Solid and Liquid Silicone Rubber

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CREATING TOMORROW’S SOLUTIONS

Wacker Chemie AG 09.19

Hanns-Seidel-Platz 4 / 81737 Munich, Germany SOLID AND LIQUID SILICONE RUBBER Phone +49 89 6279-1741 www.wacker.com/contact MATERIAL AND PROCESSING www.wacker.com Follow us on: 05.21 replaces 6709e replaces 05.21 / GUIDELINES 6709e

Section 1: Silicone Rubber – Basic Principles 6 General characteristics of silicones and why WACKER silicones are so successful. Chemical fundamentals, the most important silicone rubber grades, their components and curing mechanisms

Section 2: Silicone Rubber – Material and Processing Advantages 14 Why and when silicone rubber is the material of choice. Material and processing advantages

Section 3: WACKER Silicone Rubber Grades 20 Which applications and properties are typical? Overview of the most important applications and properties

Section 4: Material Preparation 26 Temperature, viscosity, additives and what to consider in advance. Storing and compounding silicone rubber

Section 5: Processing of Material 38 How to process silicone rubber and where to be careful. Extrusion, compression molding, injection molding and coating of textiles

Section 6: Secondary Finishing 62 How to finish cured silicone rubber. Post-curing, bonding technology, coating and printing

Section 7: Service 74 How we support you along the entire process chain. Advice on product choice, technical support, customized ready-to-use compounds, WACKER ACADEMY, e-business

Section 8: Rubber Solutions A-Z 82 Facts and figures about silicone.

ELASTOSIL®, LUMISIL®, SILMIX® and SILPURAN® are registered trademarks of Wacker Chemie AG.

3 4 WACKER is one of the world's three Close on 100 Years of Experience – WACKER Production Sites biggest silicone manufacturers. Close on 100 Years of Innovation for Silicone Rubber For over 50 years, we have been WACKER is one of the most research- Burghausen (Germany): developing, refining and producing intensive companies in the industry. Production and technical center silicones for a huge variety of We maintain our own basic-research Nünchritz (Germany): Production applications. institute as well as industry-oriented Pilsen (Czech Republic): Productio innovation teams in close contact with Adrian, USA: Production and Global Production – universities. This enables us to offer technical center Local Customer Support you ever more refined solutions. Chino (USA): Production The silicones that WACKER makes North Canton (USA): Production at its various production sites world- Silicone Rubber – Zhangjiagang (China): wide meet identical quality standards. 1,000 and More Grades Production and technical center What's more, we have set up technical Silicones can be tailored to practically Akeno-Tsukuba (Japan): centers across the globe to offer all any application. Accordingly, we have Production and technical center manner of support for product selec- a very wide and deep product range. Jandira (Brazil): Technical center tion, manufacturing, and end-product Your choice of product depends on Mumbai, India: Technical center specification. processing parameters and the prop- Amtala, India: Production erties required for the cured rubber product. Our experts will gladly assist you in choosing the right silicone grade.

5 SECTION 1: SILICONE RUBBER – BASIC PRINCIPLES

6 Basic PrinciplesBasic

Contents

General characteristics of silicones and why WACKER silicones are so successful

1.1 Chemical Structure 8 Why silicone rubber is inherently different from other elastomers

1.2 Major Classes of Silicone Rubber 9 How solid and liquid silicone rubber grades differ, and what characterizes them

1.3 Components of Silicone Rubber 10 Fillers, additives and catalysts, and their role in formulation

1.4 Curing 12 Peroxide curing and platinum-catalyzed addition curing: Two different processes and their specific advantages

7 1.1 CHEMICAL STRUCTURE

Chemical Structure

O O Si O Si O Si O Si CH2 CH CH3 3 Si CH3 C CH3 CH3

CH CH3 3 Vinylmethylsiloxane unit

Dimethylsiloxane unit

From Sand to Silicone Uncured silicone rubber contains MQ polymers of different chain lengths. MQ, or polydimethylsiloxane (PDMS), Silicones are made from quartz sand, a It always comprises a principal silicon- denotes a polymer in which two raw material available in practically unlim- oxygen chain (the siloxane backbone) methyl groups are bound to the silox- ited quantities. WACKER manufactures and an organic moiety bound to the ane backbone. silicone monomers in a closed-loop silicon. A silicon atom has four valence integrated production system based on electrons, which is why silicone rubber VMQ the Müller-Rochow process, creating is often abbreviated with a Q for VMQ stands for a polydimethylsiloxane the precursors for around 3,000 silicone “quaternary group”. The properties of in which a small number of methyl products. silicone rubber vary greatly depending groups have been replaced by vinyl on the organic groups and the chemi- groups. cal structure. Sustainable Production PVMQ The highly integrated energy and raw- The organic groups may be methyl, vi- PVMQ stands for an VMQ in which a material production system is exclusive nyl, phenyl or other groups. Depending small number of methyl groups have to WACKER. The by-products of the on which organic groups are present, been replaced by phenyl groups. chemical processes are either used im- silicone polymers in common use are mediately or returned elsewhere to the classified as follows: FVMQ production loop, so that virtually no waste FVMQ stands for an VMQ in which is generated. Waste heat is also recov- a small number of methyl groups ered and utilized, increasing the system's have been replaced by trifluoropropyl overall energy efficiency. substituents.

8 Basic PrinciplesBasic

1.2 MAJOR CLASSES

Solid silicone rubber bar Drum pair of liquid silicone rubber (standard supply form) (A and B component)

Aside from polymer structure, the Solid Silicone Rubber Liquid Silicone Rubber viscosity frequently serves as a Solid silicone rubber contains polymers Liquid silicone rubber contains polymers classification feature. A distinction with a high molecular weight and rela- of lower molecular weight and hence is accordingly made between liquid tively long polymer chains. It is referred shorter chains. It also has better flow and solid silicone rubber. to as HCR (= high consistency rubber). properties. Liquid silicone rubber is WACKER offers two product ranges always addition-curing (platinum-cat- based on solid silicone rubber: alyzed), and is marketed by WACKER a range of peroxide-curing grades as ELASTOSIL® LR (where LR stands marketed as ELASTOSIL® R (R = for liquid rubber).LSR grades are sup- Rubber) and a range of addition-curing plied as 2-component systems. The A (platinum-catalyzed) grades marketed component contains the platinum cat- as ELASTOSIL® R plus. alyst, while the B component contains The standard delivery form is as bars the crosslinker. measuring 90 x 100 mm (cross-section), • 20-kg pails with a PE inliner which are wrapped in PE film and (ø inside 280 mm) shipped in cartons. For special require- • 200-kg drums with a PE inliner ments, we also offer our ready-to-use (ø inside 571.5 mm) blends in the form of strips, round- cords, pellets and profile strips.

9 1.3 COMPONENTS

Uncured, Filled Polymer Compared with Cured Rubber

Curing

Uncured polymer with filler Polymer with chemical crosslinks (red) forms a filled, elastic network

Aside from the “pure polymer”, Crosslinkers • Reinforcing fillers: uncured silicone rubber generally A crosslinker is required to convert the Pyrogenic silica with very high BET contains only three additional raw rubber into a mechanically stable surface areas (more than 100 m2/g) substances: crosslinker, fillers and cured product. Use is made of perox- is the most frequently used reinforc- additives. ides or platinum catalyst systems (see ing filler. WACKER HDK® has proven section 1.4, pages 12-13, and 4.3, to be especially effective here, although pages 36-37). precipitated silica and carbon black can also be used. Fillers • Non-reinforcing fillers: Fillers are needed to reinforce the These have a fill-up function and are elastic silicone network. The nature, used to adjust certain properties. composition and quantity of the fillers Quartz, for example, increases the have a crucial influence on the proper- cured rubber’s resistance to various ties of the raw and cured rubber. media.

10 Basic PrinciplesBasic

ELASTOSIL® pigment pastes blend especially easily and fast into rubber compounds on the roll mill

Additives Stabilizers Colorants Compared with other elastomers, Stabilizers are available for special Silicone rubber is generally transparent silicone rubber requires few additives applications in order to optimize and can be colored as desired: because the essential properties are properties such as heat and media from transparent through translucent determined by the siloxane polymer resistance. to opaque. WACKER will supply you used. Thus, a finished polymer com- with suitable pigment pastes, both for pound may consist only of polymer liquid silicone rubber and solid silicone and filler. Particularly notable is the fact rubber. These pigment pastes are tai- that silicone rubber is free of curing lored specifically to the rubber grade accelerators or retarders, organic in question and are easily blended into plasticizers and organic antioxidants. the compound while on the roll mill or Additives include stabilizers, masticat- via metering equipment during injection ing aids and colorants. molding. It should be remembered that some additives are themselves inherently colored.

You will find additional information on fillers, additives, stabilizers and colorants in section 4.3, as from page 31.

11 1.4 CURING PEROXIDE CURING

Peroxide Curing

Vinyl group

Methyl group 150 – 200°C Peroxide decomposition with addition of the active Polydimethylsiloxane peroxo radical polymer chain to the double Reaction of the free bond radicals under formation of a chemically stable crosslink

To become an elastomeric material, Advantages Processing Information raw silicone rubber has always to Peroxide curing is a time-tested and Some peroxide crosslinkers be cured. This can be done either technically mature process. Peroxide- (ELASTOSIL® AUX Crosslinker C1 and by peroxide or addition curing. curing silicone rubber from WACKER ELASTOSIL® AUX Crosslinker C6) are has been in use for more than 50 years inhibited by atmospheric oxygen. Any Peroxide curing involves the use of and is refined continuously in close surface coming into contact with air organic peroxides. At elevated temper- cooperation with our customers. The during curing will cure incompletely atures, they decompose to form highly same applies to the production pro- and remain sticky. reactive radicals which chemically cesses, which ensure consistently high crosslink the polymer chains. The quality. You will find additional information on result is a highly elastic, three-dimen- The peroxide-containing compounds the various crosslinkers in section 4.3, sional network. WACKER offers are characterized by low sensitivity to page 36. peroxide crosslinkers in paste or catalyst poisons and have a particular- powder form. ly long shelf life.

12 Basic PrinciplesBasic

1.4 CURING PLATINUM-CATALYZED ADDITION CURING

Addition Curing

Addition of H-siloxanes to C=C double bonds

120 – 200°C

Pt-catalyzed hydrosilylation

Uncured state Elastic state

During platinum-catalyzed addition Advantages Processing Information curing, the crosslinker’s Si-H groups Unlike peroxide-curing, platinum- Even small amounts of catalyst poi- react with the vinyl groups of the poly- catalyzed addition reactions do not sons in the ambient air can inhibit the mers to form a three-dimensional net- produce odor- or flavor-impairing by- catalyst, especially amine- and sulfur- work. WACKER offers silicone rub- products. This is a major advantage containing compounds of the kind ber grades which already contain the for food-contact applications. Curing encountered during processing of or- platinum catalyst as well as grades to is fast, and the curing speed can be ganic rubber grades. For this reason, which the catalyst must be added prior controlled via the temperature. The platinum-catalyzed systems must be to use. cured rubber demolds very easily and stored and processed in a separate has a dry surface, thus facilitating room, well away from organic rubber. further processing and reducing pro- Roll mills and processing machinery duction cycle times. must always be scrupulously cleaned in order to prevent cross-contamination.

You will find additional processing information in section 5, page 39.

13 SECTION 2: SILICONE RUBBER – MATERIAL AND PROCESSING ADVANTAGES

14 Material Advantages Material

Contents

Why and when ELASTOSIL® silicone rubber is the material of choice

2.1 Material Advantages 16 Why the property range is unique, and how it differs from other elastomers

2.2 Processing Advantages 19 Where ELASTOSIL® solid and liquid rubber grades are particularly efficient

15 2.1 MATERIAL ADVANTAGES INHERENT PROPERTIES

ELASTOSIL® silicone rubber is flame SILPURAN® silicone rubber is highly ELASTOSIL® silicone rubber is extremely resistant and flame retardant. Clothing made transparent, chemically inert, does not heat resistant, odorless, tasteless and of silicone-coated fabric provides vital contain organic plasticizers and therefore permanently elastic, making it predestined protection for rescue personnel in action complies with medical standards for seals and gaskets

Silicone rubber differs from other Material Benefits Resulting from This results in the following elastomers in its unparalleled prop- the Polymer Structure properties: erty range. Of particular interest Silicones are characterized by a fully • Excellent high-temperature resistance are the characteristics resulting saturated backbone of alternating sili- combined with low-temperature not from additives or surface treat- con and oxygen atoms. The Si-O links flexibility ment but from the polymer and filler in the chain have an exceptionally high • High resistance to chemicals and structure. These are inherent prop- bond energy of 451 kJ/mol. C-C links, environmental influences erties of the silicone rubber. by comparison, have a bond energy • Water repellent surface of 352 kJ/mol. At the same time, the Si-O chain mobility is very high. The organic side groups shield the backbone, so surface energy is low.

16 2.1 MATERIAL ADVANTAGES Advantages Material GENERAL PROPERTIES

ELASTOSIL® silicone rubber withstands All ELASTOSIL® silicone rubber grades have ELASTOSIL® silicone rubber has good continuous high temperatures and dynamic good mechanical properties. Specialty grades release properties. Since it is odorless and stress, and thus represents the perfect have very high tear resistance, making them tasteless, it is suitable for the manufacture solution for turbocharger hoses ideal for bottle nipples and pacifiers of baking liners or molds

Material Benefits Resulting from the General Properties of Typical Range of Polymer/Filler Structure Silicone Rubber Mechanical Properties Silicone rubber usually contains • Broad operating-temperature • Density 1.05 – 1.60 g/cm3 pyrogenic silica as filler, e.g. HDK® range from –50 °C to +250 °C, • Shore A hardness 3 – 90 from WACKER. Pyrogenic silica is (specialty grades: • Tensile strength 5 – 11 N/mm2 structurally very similar to the polymer. –110 °C to +300 °C) • Elongation at break 100 – 1,100% They both consist predominantly of Si • Only slight changes in • Tear strength (ASTM D 624) and O which leads to very interesting physical properties between 5 – 55 N/mm properties: –50 and +180 °C • Compression set • High transparency • Excellent compression set (22 h /175 °C) 5 – 25% • Good mechanical properties thanks • Odorless and tasteless (many grades • Rebound resilience 30 – 70% to effective polymer-filler interaction are BfR and FDA compliant) • Good flame resistance; non-toxic • Can be pigmented as desired combustion products in the case • Can be easily processed of fire • Can be adjusted electrically from insulating to semiconducting • High radiation resistance • Biocompatible

17 2.1 MATERIAL ADVANTAGES

Temperature and Oil Resistance (as per ASTM-D 2000/SAE J 200) Exceptional Property Profile Elastomers are generally expected 250 FKM to be heat resistant, oil resistant and Using heat stabilizers flexible at low temperatures. Outstand-

200 VMQ ing performance in any of these prop- 80 % 40 % erties is likely to come at the expense VA HT-ACM EVM VA 44 % ACM 34 % AEM of the other ones. Silicone rubber is an ACN ACN 150 HNBR EPDM exception here: it shows excellent me- Temperature resistance* [°C] resistance* Temperature 48 % 18 % CM/CSM IIR ACN CO/ECO ACN chanical properties over a very wide NBR temperature range and exhibits satis- CR 100 SBR factory resistance to oil. Silicones also BR have an outstanding low compression NR set. 50 0 20 40 60 80 100 120 140 160 Media resistance in IRM 903 [vol %] High Purity Compared to other elastomers, Low-Temperature Flexibility versus High-Temperature Resistance silicone rubber is exceptionally pure and is therefore also suitable for use 0 in the food and medical sectors.

-20 ACM FKM Ready-to-use Compounds Silicone rubber is available as SBR CR NBR CM/CSM EVM/AEM CO/ECO HNBR ready-to-use compounds or -40 EPDM as compounds to which

Low-temperature flexibility [°C] flexibility Low-temperature the crosslinker and, if required, NR pigment, must be added. -60 IIR BR VMQ Using heat stabilizers

-80 60 80 100 120 140 160 180 200 220 240 260

Temperature resistance* [°C]

* Temperature at which – after 1000 h – half of the initial elongation at break remains.

18 Material Advantages Material 2.2 PROCESSING ADVANTAGES

ELASTOSIL® liquid silicone rubber permits Self-adhesive ELASTOSIL® silicone rubber ELASTOSIL® solid silicone rubber ensures high mass production of parts without secondary grades permit the production of composite flexibility when it comes to manufacturing pro- finishing materials in a single operation cesses and long production runs

Besides curing properties, the Advantages of Solid Silicone Advantages of Liquid Silicone processing properties also repre- Rubber Rubber sent a major criterion for the choice • Processing is highly variable, so that, • Short cycle times (low viscosity, of a suitable elastomer. Liquid and e. g. a wide range of different parts high curing speed) solid silicones each have a large can be made with a few basic silicone • Process can be fully automated number of processing advantages: grades • Molds with up to 256 cavities • High flexibility for small-to-medium • Suitable for complex part geometry series • 2K injection molding • No secondary finishing Processes: • Press curing, injection molding • Extrusion • Calendering

19 SECTION 3: WACKER SILICONE RUBBER GRADES

20 Contents

Which applications and properties are typical? Silicone Rubber Grades

3.1 Overview of Important Applications 22

3.2 Overview of Typical Properties 24

21 3.1 IMPORTANT APPLICATIONS OF SILICONE RUBBER

Automotive

– Ignition technologies, e.g. spark plug boots, pencil coils, ignition cables – Switches & buttons Transportation – Connector seals/weather packs – Exhaust pipe hangers – Profiles – Vibration dampers, e.g. engine mounts – Sound-insulation panels – Turbocharger hoses – Bellows, e.g. trains, buses – Other hoses, e.g. radiator hoses – Wall transitions – Gaskets and bellows – Floor profiles

– Water management/ – Coffee machine tubing irrigation – Oven door profiles – Sanitary – Food tubing – Bakeware & accessories Water

Food and Household

– Insulators – Insulator coatings – Cable accessories Compounding – Insulating fluids

Transmission & Distribution Industry

Please also see our applications-specific brochures on medical technology, SILPURAN®, automotive, cables and textile coatings.

22 SILPURAN Medical Technical Textile Coatings – – – – – – – Medical textile coating Medical cables Medical instruments Tubing, drainage Catheters anesthetics, e. care,Respiratory O-rings, valves, membranes Seals, gaskets, ® – – – – – Airbags e.g. sails, paragliders, tents paragliders, sails, e.g. Lifestyle textiles gloves protective clothing, door panels, e.g. insulation, textiles,Safety textilesArchitectural belts conveyor e g. Industrial textiles,

g. masks

Lighting Looking foraSpecific Product? in theproduct overviews. productsThe mostimportant are listed – – – – Gaskets /sealings Gaskets Diffusors Reflectors Lens molding Lifestyle – e.g. diving masks diving e.g. &Sports fashion, Baby – – – Baby-bottle nipples Paci articles e.g.Others, breast feeding fi ers

Industry Your ApplicationisnotListed? silicone rubberistherightmaterial foryou. will quicklytell youwhetheraparticular Why notgiveusacall?Ourspecialists – – – – – Roll coatings Conveyor belts and molded parts Extruded Window profiles pad Key

Wire/Cable – – – – – – Fire safety cable safety Fire High cable performance Ignition cable General purpose cable Battery cables Battery sleevings Electrical 23

Silicone Rubber Grades 3.2 PROPERTIES OF SILICONE RUBBER

Self-Adhesive

– Self-adhesive to PA and PBT – Self-adhesive to PC and PBT – Self-adhesive and oil-exuding – Self-adhesive and coolant resistant – Self-adhesive, oil resistant and non-abrasive Multi-Purpose Tear Resistant – Self-adhesive and flame resistant – Self-adhesive, – Standard – High tear with a high tear strength – Fast-curing – High tear – Self-adhesive, – Low compression set and fast curing with a low surface friction WACKER SILICONE RUBBER

– Flame resistant – Ceramifying Highly Transparent

Flame Resistant

Heat Conducting

Low Surface Friction/Haptic Effects

24 Looking for a Specific Product? Your Application is not Listed? The most important products are listed Why not give us a call? Our specialists in the product overviews. will quickly tell you whether a particular silicone rubber is the right material for you.

Silicone Rubber Grades

Compliance with Industrial Standards Electrically Conductive

– Food contact FDA, BfR Media Resistance – Drinking water contact WRAS, KTW, ACS, W270 – Medical/pharmaceutical – Oil and fuel resistant ISO 10993, USP Class VI, E.P. 3.1.9. – Oil and abrasion resistant – Fire safety – Coolant resistant UL 94, NFF 16101, BS 6853, EN 45545-2

– Oil-exuding, – Extremely heat resistant with varying oil content (1 – 6% oil) – Heat and oil resistant – Oil-exuding and high tear strength – Heat and solvent resistant – Oil-exuding and high cut resistance – Extremely heat resistant and – Oil-exuding and media resistant (fluorine) low compression set – Low-temperature resistant

Oil-Exuding Thermal Resistance

Low Compression Set

25 SECTION 4: MATERIAL PREPARATION

26 SECTION 4: MATERIAL PREPARATION

Contents

Temperature, viscosity, additives and what to consider in advance

4.1 Storage of ELASTOSIL® Solid Silicone Rubber 28 Optimal storage conditions

4.2 Storage of ELASTOSIL® Liquid Silicone Rubber 29 Optimal storage conditions

4.3 Compounding ELASTOSIL Solid Silicone Rubber 30 Material Preparation

Additives, colorants and stabilizers: important information on roll-mill compounding. When the method of choice is peroxide curing and when it is addition curing

27 4.1 STORAGE OF SOLID SILICONE RUBBER

® Properly stored, ELASTOSIL solid Storage-Induced Increase in General Information on Storing silicone rubber has a shelf life of Mooney Viscosity ELASTOSIL® Solid Silicone Rubber up to 12 months depending on the Long-term storage of silicone rubber • Store in closed containers in cool grade. Products which have been may cause a rise of its Mooney viscos- rooms at 0 – 30 °C stored longer may also still be us- ity. This is due to polymer/filler orien- • Do not expose to direct sunlight able. For quality assurance reasons, tation that causes stronger mutual in- • Keep separate from organic however, you should check that the teraction. However, this phenomenon rubber and crosslinker chemicals rubber still has the properties re- is reversible, and the rubber can be quired for the intended use. processed in the normal way within the Caution: given storage period. The viscosity is • If stored above 30 °C, platinum- reduced when additives are blended catalyzed grades and compounds in on a roll mill or when the rubber is containing Crosslinker E are particularly extruded or compression molded. susceptible to scorching Rubber which has been stored too • Contact with organic rubber may long can usually be made suitable for inhibit the curing system and also processing by replasticating it on a roll cause discoloration mill. If this doesn't work, a mastication aid may be used in addition. Safety Information: Please consult our safety data sheets if you require additional safety information.

28 4.2 STORAGE OF LIQUID SILICONE RUBBER Material Preparation

If kept in closed containers at 0 to Viscosity Increase General Information on Storing ® 30 °C, ELASTOSIL liquid silicone As with solid silicone rubber, the ELASTOSIL® Liquid Silicone Rubber rubber has a shelf life of up to 12 viscosity of liquid silicone rubber may • Store in closed containers in cool months from the delivery date de- increase during storage. rooms at 0 – 30 °C pending on the grade. Even if the This is due to a particular polymer/ • Higher average temperatures may product is stored for longer than filler orientation that can be reversed shorten the shelf life the recommended time, you can at any time. Despite its higher viscos- • Do not expose to direct sunlight usually still use it. For quality as- ity, the rubber can be processed in the • When opening the container, make surance reasons, however, please normal way within the given storage sure that no dirt falls onto the surface check that the rubber still has the period. When the rubber is injected of the rubber properties required for the intended into the injection molding machine, the use. screw generally causes its viscosity to Safety Information: decrease, enabling the rubber to flow Please consult our safety data sheets if better and fill the mold. you require additional safety information.

29 4.3 COMPOUNDING

ELASTOSIL® solid silicone rubber Recommendations* is characterized by its ease of • The roll mills should be temperature- processing. Most applications in- controlled (water cooling) volve the use of additives. Typical- • Friction should be about 1:1.2. If ly, the compounding components your roll mills have rough surfaces, are blended in the following order: soft formulations may stick to them rubber, stabilizers, colorant, cross- • The roll nip should be always adjust- linker. At WACKER, compounds ed in such a way to allow the forma- which do not contain additives have tion of a sufficient rubber bead the affix oH or S (standard). We offer ( = mixing zone) in the nip many solid silicone rubber grades in • First feed the harder grade onto a ready-to-process form (having the the roll mill, then the softer one, affix mH) or as a customized, ready- and homogenize them thoroughly to-use SILMIX® grade. • Homogenize the silicone rubber for 2 to 10 minutes before incorpo- rating paste additive • To speed up and optimize homogenization, make frequent incisions at the edges of the sheet, or roll it up into “dollies” and fold it back into the center of the nip

*All recommendations are intended only as a sugges- tions and not as instructions for any particular application. It is essential that you check for yourself in how far these recommendations are suitable for your application, your compound and your machine.

30 4.3 COMPOUNDING STABILIZERS AND ADDITIVES

For particularly demanding applica- depends on the crosslinker, color and Reversion Stabilizers tions, special properties of silicone operating temperature. Please note ELASTOSIL® AUX R stabilizer is used rubber can be further enhanced by that ELASTOSIL® AUX E crosslinker is as an anti-reversion agent (reversion the addition of stabilizers and other incompatible with ELASTOSIL® AUX H3 = breakdown of the network in condi- additives. stabilizer. All other heat-stabilizer grades tions that exclude oxygen). It also pre- can be used without restriction. vents a blooming effect on the surface Improving Hot-Air Resistance ELASTOSIL® AUX C1 and of non-postcured rubber products by Parts exposed to extremely high tem- ELASTOSIL® AUX C6 crosslinkers binding by-products of ELASTOSIL® Material Preparation peratures, such as turbocharger hos- can be used safely with all stabilizers. AUX E crosslinker (2,4–dichlorobenzoyl es, need to be heat-stabilized. Special They should therefore be preferably peroxide). Stabilizer ELASTOSIL® AUX oxides of transition metals (e.g. iron) used for colored compounds. As re- R simultaneously improves the rub- and special carbon blacks are particular- gards liquid silicone rubber, specialty ber's oil resistance. We recommend ly suitable for this purpose. WACKER FL pigment pastes can be added adding 0.8 – 1% paste via the roll mill. supplies ELASTOSIL® AUX H0 – H6 during pigment metering. hot-air stabilizers in the form of pastes that are readily incorporated via the roll mills. The correct choice of stabilizer

Recommendations for the Right Choice of Heat Stabilizer for HTV Grades Are Depicted in the Following Table ELASTOSIL® AUX stabilizer Recommended maximum service temperature for HTV grades Peroxide curing rubber Addition curing rubber H0 225 °C 225 °C H1 250 °C 225 °C H2 250 °C 250 °C H3 275 °C 275 °C H4 275 °C 225 °C H6 300 °C 225 °C H6 F 300 °C 225 °C

The Hot-Air Resistance of ELASTOSIL® LR Grades Can Be Improved by Adding ELASTOSIL® Color Pastes FL ELASTOSIL® Color Pastes FL Recommended maximum service temperature Ivory RAL 1014 225 °C Reddish-brown RAL 2001 225 °C Iron oxide red RAL 3013 225 °C Deep black RAL 9005 250 °C

31 4.3 COMPOUNDING STABILIZERS AND ADDITIVES

Improving Flame Resistance Adding Fillers on Roll Mills Fillers and Additives If the flame resistance of solid silicone Never add quartz powder on an open roll Additive group Additive Description /effect % Comments BfR* FDA** rubber has to be improved, we recom- mill because of the silicosis risk. It is bet- Stabilizer R ELASTOSIL® AUX Improves oil resistance and reversion 0.8 – 1 Lowers reversion tendency (thermal network breakdown) ® mend adding 2.2% ELASTOSIL AUX ter to use products already containing Stabilizer R stability Binds by-products of crosslinker E, Batch SB 2. quartz powder, such as ELASTOSIL® thus preventing surface blooming Easy to add on the roll mill R 701 or R 780/80 from WACKER. Small Heat stabilizers ELASTOSIL® AUX Milky white 0.5 – 2 May cause slight brown discoloration Using a Mold-Release Aid amounts of amorphous fillers, such as Stabilizer H0 of the cured rubber In the production of press-vulcanized diatomaceous earth or pyrogenic silica, ® rubber parts, the metal molds are ELASTOSIL AUX Reddish brown 3   can be added on a roll mill fitted with a Stabilizer H1 often treated with external release good ventilation hood. ® agents, e.g. with ELASTOSIL® AUX ELASTOSIL AUX Beige 2 Stabilizer H2 Mold Release Agent 32. The internal ® ® mold release agent ELASTOSIL® AUX ELASTOSIL AUX Jet black 1.5 Incompatible with ELASTOSIL AUX Crosslinker E   Stabilizer H3 Mold Release Agent A can serve as a ELASTOSIL® AUX Reddish brown 3 feasible alternative. The paste is incor-   Stabilizer H4 porated into the rubber in a concentra- ELASTOSIL® AUX Beige 3 tion between 0.3 and 1.0%. However, Stabilizer H6 consider the following: ELASTOSIL® ELASTOSIL® AUX Beige 3  AUX Mold Release Agent A slightly im- Stabilizer H6 F pairs the rubber's compression set. Mastication aids ELASTOSIL® AUX Enhances ease of adding and soft-rolling 1 – 3   We therefore strongly advise you to Mastication Aid 4 properties on the roll mill, and stabilizes the conduct thorough tests before using it! viscosity Mold release agents ELASTOSIL® AUX Improves mold-release properties; a deter-   Mold Release Agent 32 gent which is sprayed onto the mold ELASTOSIL® AUX Improves mold-release properties; paste for 0.3 – 1 Has a negative effect in the compression set test   Mold Release Agent A adding to the solid rubber and should only be used after thorough testing

Flame resistance ELASTOSIL® AUX Improves flame resistance 2.2 Batch SB 2 Foam batches Upon request

32 You Don't Do your Own Compounding? WACKER supplies almost 1.000 different ready-to-use rubber grades. We also supply additional, customized grades whenever required. Just ask us about our SILMIX® system!

Fillers and Additives Additive group Additive Description /effect % Comments BfR* FDA** Stabilizer R ELASTOSIL® AUX Improves oil resistance and reversion 0.8 – 1 Lowers reversion tendency (thermal network breakdown) Stabilizer R stability Binds by-products of crosslinker E, thus preventing surface blooming Easy to add on the roll mill Heat stabilizers ELASTOSIL® AUX Milky white 0.5 – 2 May cause slight brown discoloration Stabilizer H0 of the cured rubber ELASTOSIL® AUX Reddish brown 3   Stabilizer H1 ELASTOSIL® AUX Beige 2 Material Preparation Stabilizer H2 ELASTOSIL® AUX Jet black 1.5 Incompatible with ELASTOSIL® AUX Crosslinker E   Stabilizer H3 ELASTOSIL® AUX Reddish brown 3   Stabilizer H4 ELASTOSIL® AUX Beige 3 Stabilizer H6 ELASTOSIL® AUX Beige 3  Stabilizer H6 F Mastication aids ELASTOSIL® AUX Enhances ease of adding and soft-rolling 1 – 3   Mastication Aid 4 properties on the roll mill, and stabilizes the viscosity Mold release agents ELASTOSIL® AUX Improves mold-release properties; a deter-   Mold Release Agent 32 gent which is sprayed onto the mold ELASTOSIL® AUX Improves mold-release properties; paste for 0.3 – 1 Has a negative effect in the compression set test   Mold Release Agent A adding to the solid rubber and should only be used after thorough testing

Flame resistance ELASTOSIL® AUX Improves flame resistance 2.2 Batch SB 2 Foam batches Upon request

* BfR XV, Part A, “Silicones”, 182. Communication BGBl. 32, 211 (1989). ** FDA Chapter 21 CFR § 177.2600 Rubber Articles Intended for Repeated Use.

33 4.3 COMPOUNDING COLORS

WACKER is a “one-stop supplier”. lab. For special regulatory requirements Processing Tip We can supply you with suitable we offer a broad range of FDA- and We recommend to homogenize PT pigment pastes for both solid sili- BfR-compliant pigments. We will gladly color pastes on the mill and FL color cone rubber grades (ELASTOSIL® advise you on existing dosage limits pastes through stirring before use. In PT pigment pastes) and liquid prescribed by these standards. Please general, PT color pastes are dosed silicone rubber grades (ELASTOSIL® also contact us if you require pigments with 1%, FL pastes with 2%. Please FL pigment pastes). To ensure op- compliant with USP Class VI und ISO note the specific exceptions like e.g. timal processing, the viscosity of 10993. for color paste 9005. these pastes is adjusted to match that of our silicone rubber grades. Adjusting Colors with PT Pastes on the Roll Mill Looking for a Special Color? Choosing your Color We recommend adding the PT pigment Should you require a particular color not Choose the color you would like from pastes together with the crosslinker included in our standard pigment paste our range of standard and special col- because a homogeneously colored range, we will formulate a customized ors (see table on page 35). As our material will then indicate uniform paste on request. Just contact us! pigment additives can be mixed to- crosslinker distribution. gether in any ratio, almost any desired color can be obtained. Our technical support specialists will gladly assist you in mixing a specific color in their

The conformity values quoted in the table alongside are not guaranteed because the relevant regulations can change. Please consult our Technical Service for the latest data.

1 The RAL values in the table are only a guide. 2 BfR and FDA compliance necessitates adhering to existing dosage limits. We will be glad to assist you. 3 Not suitable for use with crosslinker E. 4 For questions regarding the biocompatibility of our FL pigment pastes, please contact our technical service department. 5 Please consider the defined time-temperature use conditions (B-H) acc. to table 2 under 21 CFR §176.170. 6 Please consider the defined time-temperature use conditions (C-H) acc. to table 2 under 21 CFR §176.170. 7 Only analogous certificates possible

34 Our ELASTOSIL (exposure inUVweathering chamber).For higher requirements pleasecontactour technical service. Color name Black Black Deep black Dark brown Pale brown Gray Green Light blue Dark blue Ultramarine blue Reddish-violet Red Red Orange Orange Yellow Yellow Yellow Other colors Universal Black White Blue Reddish-brown ELASTOSIL Black Deep black Gray Green Helio green Light blue Dark blue Ultramarine blue Reddish-violet Red Red Dark red Orange Orange Reddish-brown Yellow Yellow Yellow Yellow Yellow Ivory Other colors Deep black White Blue Iron oxide red Helio green Color name Yellow Standard colors Yellow Standard colors ELASTOSIL ® PTColorPastes ® ® FL Color Pastes Color FL AUX PTbzw. FLshow aminimumtemperature resistence of42d/175°Cor21d/200°C oraUV-resistance of21d Similar to RAL RAL 9011 RAL 9017 RAL 9005 RAL 8015 RAL 8003 RAL 7040 RAL 6017 RAL 5015 RAL 5010 RAL 5002 RAL 4002 RAL 3000F RAL 3000 RAL 2004F RAL 2004 RAL 1033 RAL 1026F RAL 1021 RAL 9010 RAL 5022 RAL 3013 RAL 9005F RAL 9005 RAL 7000 RAL 6010 RAL 6004 RAL 5015F RAL 5010 RAL 5002 RAL 4002 RAL 3020 RAL 3000F RAL 3000 RAL 2004F RAL 2004 RAL 2001 RAL 1033 RAL 1026F RAL 1026 RAL 1021 RAL 1006 RAL 1014 RAL 9011 RAL 9010 RAL 5022 RAL 3013 RAL 6004 Similar to RAL RAL 1016 RAL 1016 5 3 5 5 5 5 3 5 5 3 6 5 6 5 1 1                         BfR                      BfR 2 2                      FDA FDA

                

2 2              10933 /ISO VI Class USP            10933 /ISO VI Class USP  4 7 Color Color

Material Preparation 4.3 COMPOUNDING PEROXIDE CURING

WACKER offers three different per- For Vulcanization under Pressure For Vulcanization under Pressure oxide crosslinkers for the peroxide- or in Steam: or in Steam: curing of solid silicone rubbers. ELASTOSIL® AUX Crosslinker C1 ELASTOSIL® AUX Crosslinker C6 ELASTOSIL® AUX Crosslinker C1 ELASTOSIL® AUX Crosslinker C6 is For Pressureless Vulcanization: is used for producing compression only used for processing rubber in ELASTOSIL® AUX Crosslinker E molded articles. ELASTOSIL® AUX compression molds and is easily incor- We recommend ELASTOSIL® AUX Crosslinker C1 is hardly affected by porated as a paste on the roll mill. Like Crosslinker E for pressureless vulcani- temperature and can be handled safely ELASTOSIL® AUX Crosslinker C1, zation, e.g. for the extrusion of hoses, under typical processing conditions. It Crosslinker C6 is largely unaffected by profiles and the like. decomposes at 155 °C. temperature. It is stable up to 160 °C, making processing particularly unprob- Processing tips: Processing tips: lematic. It is important to remember that • Add the crystalline crosslinker at ELASTOSIL® AUX Crosslinker E begins about 45 °C. At this temperature, the Processing tips: to react at approx. 100 °C: crystals melt and the liquified cross- Avoid contact with atmospheric • Always cool the rolls (< 60 °C) linker is distributed homogeneously oxygen: all surfaces that come into • Never roll up the rubber sheet into • Intensive cooling of the roll mill is contact with oxygen during cross- thick “dollies”. Lay it out to cool for unnecessary linking remain sticky. approx. 30 minutes in strips not • The sheeted out rubber may be thicker than 15 mm, either open to thicker than 15 mm in this case, and the air or covered loosely with a it can be folded into a zig-zag when PE film laid out • Store catalyzed rubber compounds • Avoid contact with atmospheric at a temperature below 30 °C to oxygen: all surfaces that come into prevent premature curing contact with oxygen during crosslinking remain sticky

Peroxide Crosslinkers Name/grade Peroxide % Vulcanization [°C] Processing ELASTOSIL® AUX (50% paste in silicone fluid) bis- 1.5 – 1.8 > 100 Especially suitable for rubber that is Crosslinker E (2.4-dichlorobenzoyl-)peroxide vulcanized under low-pressure conditions, especially for the extrusion of hoses and profiles ELASTOSIL® AUX Dicumyl peroxide (98%), 0.6 – 0.9 165 – 190 For manufacturing molded parts Crosslinker C1 crystalline powder ELASTOSIL® AUX (45% paste in silicone rubber) 0.6 – 1.5 170 – 190 For manufacturing compression molded Crosslinker C6 2,5-bis-(tert.-butylperoxo)-2,5 parts, easy to add on the roll mill dimethylhexane

36 4.3 COMPOUNDING PLATINUM-CATALYZED CURING

We recommend platinum-catalyzed • 2-part system: separated from organic rubber during addition curing for all applications in The catalyst is added later. WACKER storage and processing, and always which it is important that: offers the catalysts ELASTOSIL® AUX clean roll mills and processing • No odor or flavor is produced Batch PT 1 (for extrusion) and PT 2 machinery meticulously to avoid (e.g. for food-contact applications) (for molded articles). For example, cross-contamination. • No volatile peroxide by-products are the catalyst PT 1 is used with the released grade ELASTOSIL® R plus 4305. Storing and Adding Crosslinker • Transparent articles do not discolor • Always store peroxides in cool rooms during post-curing Processing tips: • Shelf life approx.12 months • Curing is fast and cycle times Platinum-catalyzed 2-component • To ensure homogeneous distribution,

therefore short grades may start crosslinking slightly Material Preparation spread pasty crosslinkers onto the • The cured product is readily demold- even at room temperature; as a result, sheeted-out rubber during roll milling able and has a dry surface it is important not to exceed the shelf • Add powdered crosslinkers portion-wise, life. We recommend carrying out pre- and avoid inhaling any dust WACKER Offers Two Types of liminary tests to ensure that the rubber Solid Silicone Rubber for these still has the required processing prop- Tip Applications: erties. It is important Any special requests? • Ready-to-process compound: that all batches are stored for the Further crosslinkers are available for The platinum-catalyst is already con- same length of time between com- special requirements tained in the rubber formulation pounding and processing. Catalyst (1-part compound), as typified by the poisons in the ambient air inhibit curing. grade ELASTOSIL® R plus 4001. This is particularly true of amines and sulfur containing compounds, which are common components of organic rubber systems. So always keep platinum-catalyzed silicone rubber well

Platinum Catalysts Crosslinkers % Vulcanization [°C] Recommended for Recommended for rubber grades processing ELASTOSIL® AUX Catalyst paste 1.5 – 2 165 ELASTOSIL® R plus Extrusion Batch PT 1 ELASTOSIL® AUX Catalyst paste 1.5 – 2 165 ELASTOSIL® R plus Molded articles Batch PT 2 SILPURAN® Catalyst paste 1.5 – 2 165 SILPURAN® Extrusion of medical Curing Agent X articles SILPURAN® Catalyst paste 1.5 – 2 165 SILPURAN® Molded medical articles Curing Agent M We offer additional catalysts for textile coating formulations and will gladly advise you on your specific application.

37 SECTION 5: PROCESSING THE MATERIAL

38 Contents

Everything you need to know about processing ELASTOSIL® silicone rubber

5.1 Introduction 40 When to use which process, and which material is suitable

5.2 Extrusion 41 Metering, conveying, extrusion die, vulcanization, troubleshooting

5.3 Press Molding 48 Compression molding, transfer molding and what to consider

5.4 Injection Molding 50 Metering and mixing, injection and vulcanization, demolding, 2K injection molding, troubleshooting

5.5 Textile Coating 60 Material Processing Which properties can be achieved, which silicones are suitable and which processes are most important

39 5.1 INTRODUCTION

ELASTOSIL® silicone rubber can be processed in a variety of ways. The main processes include extrusion, coextrusion, compression molding, transfer molding, injection molding and knife coating (on textiles). Calendering and low-pressure filling are also possible.

Selecting the Best Process Since the choice of process always depends on a number of factors, the following questions should be clarified: • How are the properties specified for the application? • Which chemical and physical properties is the vulcanized rubber required to have? • How large is the required production series? • Is liquid or solid silicone rubber the right choice? • Which sort of geometry does the part have? Complex or simple? Extrusion of ELASTOSIL® solid silicone rubber into tubing • Which equipment is available and how much investment is required, if any? Selection of the Rubber Grade by Process • What experience/expertise Processing Solid silicone rubber Liquid silicone rubber is available for the particular Extrusion • processes? Coextrusion • Compression molding • A rapid decision can then be made Transfer molding • about which processing technique to Injection molding • • choose. For complex part geometries Doctor blade • • Calendering • in large quantities, for example, injection Low-pressure filling • (low-viscosity grades) molding is recommended, while extrusion is to be preferred for producing continuous articles.

40 5.2 EXTRUSION

Schematic Diagram of an Extruder with Crosshead Die

Feed hopper

Crosshead

Extrusion is a continuous manufacturing process in which silicone rubber is squeezed through a die and then vulcanized. The die gives the Conveying screw extrudate its shape. The required Material Processing pressure is produced via a convey- Extrusion die ing screw, in which the material is homogenized, compressed and deventilated.

Typical Application Selection and Preparation Screens of approx. 100 µm mesh Extrusion is mainly used for the of the Material remove foreign particles, homogenize following products: Peroxide and addition-curing the material, and eliminate any trapped • Tubing ELASTOSIL® solid silicone rubber air. • Profiles grades are suitable for extrusion. • Cables The materials are either available as • Flat tape ready-to-process compounds or have • Round cord to be compounded in advance.

For this purpose, the rubber is compounded with the required additives and crosslinkers on the roll mill. To eliminate contaminants from the rubber compound, it should be subse- quently passed through a strainer.

41 5.2 EXTRUSION METERING

RotoFeeder® as metering unit for extrusion Interior of the RotoFeeder®: CTM® from Colmec and injection molding Feed hopper with conveying screw

The extruder should be fed as Manual Feeding Automatic Feeding uniformly as possible. This can be For manual feeding, a sheet is pro- Feeding and metering can be per- done manually, semi-automatically duced on the roll mill, cut into strips formed automatically using appropriate or automatically. and fed into the feed hopper manually. auxiliary equipment (e. g. PolyLoad® from Krauss Maffei, RotoFeeder® from Semi-Automatic Feeding Engel or CTM®-System from Colmec). We offer special delivery forms for The material is transferred to a reserve semi-automatic feeding. The rubber container containing one or more strips have already been wound into screws. The screw feeds the extruder coils in the plant. They can be placed continuously via the outlet opening. on a rotating disk coiler. Operation can For this purpose, ELASTOSIL®/ be integrated directly into the extrud- SILPURAN®/SILMIX® solid silicone er’s machine control. Alternatively, the rubber can be used in all delivery coil strips can be introduced directly forms. from the cardboard box via a take-off unit.

RotoFeeder® is a registered trademark of Engel. PolyLoad® is a registered trademark of Krauss Maffei. CTM® is a registered trademark of Colmec.

42 5.2 EXTRUSION CONVEYING IN THE SCREW

Open extruder with conveying screw Material Processing

The screw performs several func- Screw Design • Typical screw dimensions are tions during the process, it conveys • Feeding is facilitated by maximum length: diameter = 10 : 1 to 12 : 1 and compresses the rubber while flight clearance in the screw feed • The screw and cylinder jacket must at the same time building up the zone. Slots in the flights have also be cooled to prevent scorching of pressure for deaeration of the mate- proved successful the material rial. Homogenization, back venting • One or two-flight screws with com- and output rate can be controlled pression ratios from 1 : 1.5 to 1 : 2 by varying the screw geometry and can be used. Twin-flight screws machine parameters. increase output • A progressive core or flight pitch is an advantage. With progressive cores, the core diameter increases gradually from the feed zone towards the screw tip. With a progressive pitch, the flight pitches decrease towards the screw tip

43 5.2 EXTRUSION EXTRUSION DIE

The extrusion die determines the Projection of the Die Geometry profile of the cured rubber. Die design does not require any specific Make the die edges concave measures for silicone rubber; the customary guidelines apply.

• The wall should have the same Extrusion die thickness in all areas of the die • Avoid sharp edges or corners: they can cause rough surfaces on the extrudate • Avoid dead corners and sudden changes in direction of flow: material can accumulate in the dead corners Extrudate and vulcanize • It is important to have a uniform flow rate across the cross section. Mate- Uncorrected shape Corrected shape rial more distant from the die center has a slower flow rate. For the production of straight edges a concave Design of the Edges of a Die for an Open Profile design of the die edges is required

Avoid sharp edges/corners Compensating the Die Swell The extrudate swells as it leaves the die. This phenomenon is affected by: • Viscosity: the lower the viscosity, the greater the die swell • The material temperature: the Unsuitable design Better design higher the temperature, the greater the die swell • The extrusion velocity: the faster the extrusion, the greater the die If the take-off belt of the heating tunnel swell runs faster than the extrudate leaves • The die diameter: the smaller the die, the die, stretching occurs. This can the greater the die swell be used to adjust the desired diameter of the extrudate. As a result, die swell can be compensated and cured products manufactured with diameters smaller than the die orifice.

44 5.2 EXTRUSION VULCANIZATION

Cable production: extrusion with subsequent vulcanization in the infrared tunnel Material Processing

Extrudates are usually vulcanized Vulcanization in Heating Zones To avoid pressure marks resulting from via vertical or horizontal heating without Pressure the conveyor belt, a shock tunnel can zones, with or without pressure. Tubing and profiles are usually vulca- be fitted upstream in horizontal heat- Silicone rubber is usually not nized in a heating zone (at 200 – ing zones to prevulcanize the parts at vulcanized in a salt bath, though 500 °C) without the application of about 600 °C. this option is possible in principle external pressure. Horizontal or vertical In many instances, it is preferable to for peroxide-curing compounds. heating tunnels are heated by means extrude vertically using an extruder of resistance heaters, infrared heating head deflected through 90°. This bars with reflectors, hot-air systems or prevents belt pressure marks, so that ceramic dark radiators. The extrudates even very soft materials can be easily are conveyed on sheet-steel or mesh processed. conveyor belts. The conveyor belts run on movable deflector rolls to compen- sate for the thermal expansion of the belt. Their velocity can be regulated. The conveyor belt return should be located in the heating tunnel to prevent excessive cooling. If this is not possible, use covers to prevent rapid heat loss.

45 Hose vulcanization in a horizontal hot-air tunnel

Vulcanization in Heating Zones with General Information on Extrusion Coextrusion Pressure Cooling: Coextrusion allows extrudates to be Continuous vulcanization (CV) lines are During extrusion, high shearing rates produced from different materials. For primarily used to manufacture cables. occur, which generate heat. example, it allows the manufacture of Heating is usually by means of pres- • To avoid scorching, the extruder, screw striped tubes, pigmented extrudates, surized steam. and extruder head should be cooled to or sheets with an extruded-on profile. The line is usually fed with steam at a ensure that the rubber temperature lies WACKER offers self-adhesive pressure of 4 to 20 bar. At least 6 bar safely below the decomposition temper- ELASTOSIL® R plus grades for this is necessary to achieve the required ature of the peroxide purpose. vulcanization temperature. Different • In addition, the highest output rates are steam temperatures are reached, obtained when the cylinder is cooled depending on the supply pressure. With this process, the extruder head is Extruder Size: continually supplied with saturated • Extruders with 45 to 90 mm screw steam. To prevent scorching, the ex- diameter and an L/D ratio of 10 : 1 to truder head must be intensively cooled. 16 : 1 (typically 10 : 1 to 12 : 1) are most The vulcanization time depends on the commonly used length of the zone, the temperature, • The bigger the extruder, and therefore and the wall thickness of the insulation. the screw, the lower is the speed, and It is usually between 30 seconds and therefore the heat of friction for the 2 minutes. same output

46 5.2 EXTRUSION TROUBLESHOOTING

Fluctuations in the extrudate geometry

The following table shows the Overview most common faults and possible Fault Possible cause causes. If you still have any ques- Bubbles Atmospheric moisture on machines, air inclusions tions, please ask your WACKER Fisheyes No strainer sieve, scorching of particles due to contact or call the WACKER info excessive material temperature, inhomogeneous Material Processing line. mixing Brittle extrudate/white stripes when Material damage due to high curing temperature the extrudate is stretched In General, to Avoid Problems: Round, soft region in the center of Insufficient curing, line speed too high or • The material has to be mixed the extrudate temperature too low homogeneously and has to be Sharp edges on the extrudate have Poor die design free of impurities a sawtooth structure • The extruder should be thoroughly Fluctuation in the extrudate geometry Fluctuations in the material pressure or cleaned between two production temperature runs Rough surface Scratched/damaged die surface, material temperature too high • Fluctuations in the material temperature and pressure should be avoided • Material feed into the extruder should be uniform • Strainer screens should be used (for ventilation of the material and to avoid pressure fluctuations) • All machines should be regularly maintained

47 5.3 PRESS MOLDING PROCESSES COMPRESSION AND TRANSFER MOLDING

Press molding processes are used Compression Molding for a wide range of applications. ELASTOSIL® solid silicone rubber is vulcanized in molds by heat and pressure. Compression and transfer molding are the preferred methods Movable (top) for solid silicone rubber. mold half

Material Selection/Mold Filling For compression molding, peroxide- Silicone rubber curing and platinum-catalyzed Fixed (bottom) ® ELASTOSIL solid silicone rubber mold half grades are preferred. Each cavity is individually filled with a precisely weighed amount of rubber. Ejector

Pressing/Vulcanization The platen presses are usually hydrau- lically operated, they are heated, e.g. electrically or with steam. For vulcanization of peroxide mixtures with Demolding However, it should be correctly me- ELASTOSIL® AUX Crosslinker C1 or External and internal mold-release tered. Too much release agent can C6, and for platinum-catalyzed solid agents can be used to assist lead to mold contamination by form- silicone rubber, a mold temperature demolding. ing deposits on the hot mold wall. It of about 150 to 200 °C is usually cho- can also cause inhomogeneities in sen. The temperature plays an important • External release agents : the end product. If the mold release role: it is required to be as high as In this case, a 1 – 3% aqueous agent is pushed forward by the flow possible to shorten the vulcanizing solution of the mold release agent front during mold filling, it can lead to time, and therefore the cycle times. ELASTOSIL® AUX Mold Release (undesirable) weld lines as a result of However it must not be too high, since Agent 32 is sprayed into the hot incomplete welding of the merging scorching may otherwise occur. The mold. The process is repeated as flow fronts. In both cases, the end vulcanizing time is determined by the required. product is no longer usable. temperature of the material, the mold • Internal mold-release agents: Alter- temperature and the thickness of the natively, ELASTOSIL® AUX Mold part. Release Agent A can be added to the silicone rubber.

48 Transfer Molding Die Cutting/Slitting Die cutting offers an economic alternative for very small quantities. In this process, parts such as O-rings are die cut from extruded, calendered or pressed sheet. Plunger Note that silicone rubber grades with high Transfer plunger notch resistance are not easy to die cut. It is better to use blends of elastic grades Silicone rubber and standard extrusion grades. Always Runner carry out tests in advance.

Mold cavity Molded part For Safety's Sake • Please follow the instructions in our material safety data sheets Ejector • We recommend using an extractor to purify the room air Material Processing Transfer molding is a development Material Selection/Mold Filling of compression molding. It is more The pot is charged with a defined economic for small-volume parts with amount of silicone rubber. A plunger complex geometries, which are pro- then forces the rubber through a duced in large quantities and with less runner into the mold. For greater manual work (no secondary finishing). economy, several molds can be filled It differs from compression molding in by using a sliding table unit or runner that the mold is charged via a chamber manifold. (the “pot”) with runner. Transfer molding is particularly suitable for producing moldings in which high dimensional accuracy is required (precision parts).

49 5.4 INJECTION MOLDING

Injection molding is currently the Advantages of Injection Molding Material Selection most popular and efficient method Injection molding is characterized by ELASTOSIL® solid silicone rubber and of processing large quantities of high dimensional accuracy. It produces ELASTOSIL® liquid silicone rubber are silicones where there are strict high quality parts without secondary both suitable for injection molding. demands for consistently high finishing, and allows much shorter pro- product quality. duction cycles than other processes. The disadvantages are higher mold and machine costs, though these can be offset by the high productivity.

Typical Applications Injection molding is particularly suitable for the production of large numbers of small to medium-sized parts, such as: • Nipples for baby bottles • Gasket rings

50 5.4 INJECTION MOLDING METERING AND MIXING

Mixing and Metering Equipment for Liquid Silicone Rubber Mixing A static or dynamic mixer can be used. Static mixers do not have mov-    Metering unit for the ing parts; the material is homogenized A and B components of the  liquid silicone rubber via fixed mixing elements in the interior. Dynamic mixers have moving parts  Metering unit for pigment/ supporting the homogenization. Static additives mixers are typically used for liquid silicone rubbers. After the two compo-  Mixing station nents A and B have been mixed, the  Metering cylinder material can be injected into the mold.   Heated injection mold with Injection injection-molded part  The mixed material is metered and injected into the mold with a screw in  the injection cylinder. Modern injection molding machines offer precise control of the injection process.

Pot Life Material Processing At room temperature (about 20 °C), Due to their widely differing vis- Metering the A/B mixture has a pot life of at cosities, liquid and solid silicone The metering units pump the A and B least three days. If the temperature is rubbers are metered and mixed components of liquid silicone rubber higher, the pot life may decrease differently. directly from the pails or drums in a correspondingly. To prevent premature ratio of 1 : 1 and feed it to a mixer, and vulcanization, it is advisable to thermo- ELASTOSIL® Liquid Silicone then to the feed dosing cylinder of the stat the metering cylinder and mixer. Rubber injection-molding machine. If required, The injection unit should be rinsed with Liquid silicone rubber grades require ELASTOSIL® Pigment Paste FL can be one of the components, preferably the special metering and mixing systems. fed to the mixer via an additional pig- A component, before relatively long ment line. production breaks of more than three days.

51 ® ELASTOSIL Solid Silicone Rubber Metering Please Note ® ELASTOSIL solid silicone rubber for Solid silicone rubber is generally me- • The A and B components of liquid injection molding is available in two tered to the injection molding machine silicone rubber should have the same supply forms: via a stuffing box. It is generally per- batch number, since the curing systems • As ready-to-process material in formed either semi- or fully automatically are matched to one another within a different delivery forms. Preferably in the case of profile strips. As an alter- batch ® as bars, but also as strips or round native to the stuffing box, RotoFeeder • If the silicone rubber contains abrasive ® cord, etc. (Engel) or PolyLoad (KraussMaffei) fillers, the cylinder, screw, non-return • As a silicone rubber base compound, systems can be used. valve, needle valve, sprue and runners to which the crosslinker and possibly must be hard-faced other additives are added. This is The cylinder and discharge from the usually performed via roll mills (see stuffing box are usually maintained at section 4, page 30) 40 – 50 °C to facilitate material feed.

RotoFeeder® is a registered trademark of Engel. PolyLoad® is a registered trademark of Krauss Maffei.

52 5.4 INJECTION MOLDING INJECTION AND VULCANIZATION

ELASTOSIL® Liquid Silicone Rubber Indirect Gating Direct Gating There are two types of sprue system: The material is injected into the cavities In this case the material in the cold indirect gating via a cold runner and through a cold runner, via a manifold. runner is injected into the part. A cold hot sub-runner, or direct gating. The The vulcanized sprue waste must be runner with needle valve offers addi- cold runner may have a hydraulic nee- removed from the mold together with tional processing advantages, such dle valve. Each gating method has its the molding, and discarded after sepa- as low shearing during injection. pros and cons. ration from the molded part. • Advantages: • Advantages: – Articles do not require secondary – Less expensive mold making finishing – Suitable for small and – High degree of automation medium-sized series possible • Disadvantages: – Low material consumption – High material consumption (no sprue waste) (sprue waste) – Can also be used for rapid curing – Secondary finishing of the parts is systems required (to remove the sprue) • Disadvantages: – Not suitable for fast-curing systems – Expensive mold design/production (risk of premature curing in the run- – Higher costs for multicavity molds ners) (a cold runner for each cavity) is

required Material Processing

Comparison: Indirect and Direct Gating via Cold Runner

Open cold runner Injection nozzle Water cooling Top mold half Top mold half

Sprue

Bottom mold half Silicone molded part Bottom mold half Silicone molded part

53 Vulcanization ELASTOSIL® Solid Silicone Rubber The curing temperatures and times In general, it offers the same advantag- depend on the quality of the heating es as liquid silicone rubber. However, system and on the material, volume due to the higher viscosity, the runner and geometry of the rubber part. cross-sections are generally larger. ELASTOSIL® liquid silicone rubber is usually processed at between 150 and Curing 200 °C. Solid silicone rubber is processed at between 150 and 200 °C.

54 5.4 INJECTION MOLDING DEMOLDING

Vulcanized silicone rubber tends to stick to the mold wall. This can be solved in various ways.

Multiple Process Passes Demolding may be more difficult at the beginning of the process. After multiple cycles, a release layer resulting from the silicone rubber forms on the mold surface, and assists in demolding (cf. diagram).

Mold Release Agents The use of mold release agents, e. g. ELASTOSIL® Mold Release Agent 32, aids demolding on process startup.

Auxiliary Equipment The parts are generally demolded by Demolding an injection molded sheet from the mold means of ejector pins and brush or Material Processing blower units. Schematic Course of Demoulding Force Demoulding force Demoulding

Number of cycles

55 5.4 INJECTION MOLDING 2K INJECTION MOLDING

Multicomponent parts can be manu- Process Options • 2K injection molding on two injection factured by 2K injection molding. Combination parts can be produced molding machines: • Soft-hard combinations by different processes. This is a two-stage process with two (combinations of silicone rubber • Insert process: machines: the thermoplastic backing with thermoplastic or metal parts) Prefabricated hard components part is molded on the first machine in • Silicone rubber/silicone rubber (thermoplastics, glass or metal) are a thermoplastic mold. While the part combinations (e. g. color combina- inserted in the cavity on a 1K injec- is still hot, a gantry robot transfers tions or combinations of grades tion molding machine and then it to a silicone mold on the second with different hardnesses) overmolded with ELASTOSIL® liquid machine, where it is overmolded with silicone rubber. Before insertion, liquid silicone rubber. Advantages of 2K Injection Molding metals should be degreased with a • Excellent adhesion of the solvent such as ethanol or acetone. components With thermoplastics, ensure that they • Greater scope for designers have first been properly dried, since (color combinations, etc.) adsorbed moisture leads to poor ad- • Soft or non-slip surfaces hesion. With difficult material com- can be produced in one step binations, adhesion can be assisted • Outstanding sealing, e. g. against by, e. g. flame, corona or plasma dust or condensation treatment. • 2K injection molding on one injection Material Selection molding machine: WACKER offers self-adhesive A 2K injection molding machine with ELASTOSIL® silicone rubber. rotary table produces combination For more information, please see parts in one step. In the first position, our product overview leaflets. the parts are molded from thermoplastic. The moldings are then transferred to position 2 on the turntable, where they are overmolded with liquid silicone rubber.

56 Diagram ComparingtheDifferent 2KInjectionMoldingMethods 2K injection molding on two injection molding machines 2K injection molding on one injection molding machine process Insert 57

Material Processing 5.4 INJECTION MOLDING TROUBLESHOOTING

Troubleshooting Symptoms Moldings not Overpacking/flash Mold adhesion/ Air inclusions/ Burn marks/ Weld seam Part deformation/ Defects in the Irregular mold Fluctuations from Underfilling Sink marks fully crosslinked parts not demoldable bubbles white spot scorching molding filling shot to shot Possible Causes Mold temperature too low   Mold temperature too high      Mold has excessive  undercuts Mold surface too smooth  Inadequate mold balancing    (cold runner/manifold) Mold defective  Heating time too short    Clamping force too low  Inhomogeneous temperature     distribution in the mold Inadequate deaeration/       vacuum Injection too fast       Injection too slow   Nonreturn valve faulty   Holding pressure too high/   too long Too little material  Switchover point to holding    pressure incorrect Deviations in mixing ratio of   the components Poor material mixing  Faulty shut-off valve on   material feed Air in the material feed    

58 Troubleshooting Symptoms Moldings not Overpacking/flash Mold adhesion/ Air inclusions/ Burn marks/ Weld seam Part deformation/ Defects in the Irregular mold Fluctuations from Underfilling Sink marks fully crosslinked parts not demoldable bubbles white spot scorching molding filling shot to shot Possible Causes Mold temperature too low   Mold temperature too high      Mold has excessive  undercuts Mold surface too smooth  Inadequate mold balancing    (cold runner/manifold) Mold defective  Heating time too short    Clamping force too low  Inhomogeneous temperature     distribution in the mold Inadequate deaeration/       vacuum Injection too fast      

Injection too slow   Material Processing Nonreturn valve faulty   Holding pressure too high/   too long Too little material  Switchover point to holding    pressure incorrect Deviations in mixing ratio of   the components Poor material mixing  Faulty shut-off valve on   material feed Air in the material feed    

59 5.5 TEXTILE COATING

Silicones are the right solution for a Silicones can be used for coating Info variety of coating requirements. Their nearly any type of fabric. The art of We will advise you on formulations and special chemistry makes them per- formulation requires a great deal of will conduct application-related testing fect for a wide variety of uses. experience and creativity and a wealth for you. We will gladly show you the op- of knowledge about relevant chemical portunities and advantages of innovative This is mainly due to their special and processing relationships. coating technologies that meet your chemistry. What’s more, their basic WACKER SILICONES’ technical service individual needs. Upon request, we can structure can be varied in almost any specializes in precisely that. We help also carry out pilot runs for you (product way as a result of chemical modifica- you manage the often difficult balanc- width up to 90 cm). tion or skillful combination of additives. ing act between product, coating system and substrate in order to achieve the perfect end result.

60 textile functionality. such asELASTAN coatings forhighlyelastictextiles – As such,theycanbereliably usedas break over1,000%forsomegrades. elastic materials, withelongationat Silicone elastomers are extremely Elasticity tional andprotective clothing. ture, food,lifestyle,aswellfunc- in suchdifferingareas asarchitec- impress withtheirhighfunctionality, SILICONE PROPERTIES TEXTILE COATING 5.5 coated withELASTOSIL e.g. fortextiles, too. Textile materials prove itindiverseapplicationareas – multifunctional “natural talents”and No problem forsilicones.Theyare Materials withspecificproperties?

® –withoutlimiting ® silicones

to UVdamage. bemorewould otherwise susceptible can alsoprotect textile fibersthat UVlight,siliconecoatingsshort-wave properties. Sincesiliconesabsorb cycles withnochangeintheirsurface specialty blendswithstand1.5million (2 l sulfurdioxide) hasshownthat described inDIN50018–SFW 2.0 S ering. Theindustrialclimate test them exceptionally resistant to weath- able chemicalresistance, thismakes hydrophobic properties andconsider to UVradiation. Combinedwiththeir Silicones are extraordinarily resistant UV andWeathering Resistance fire-safety requirements. textiles alsomeethighlystringent additives ensure thatsilicone-coated non-corrosive andnon-toxic. Special as white ash);thegases formedare to silicondioxide (whichaccumulates In theeventofafire, silicone reverts of siliconeelastomers isapprox. 430°C. polymers. Theautoignition temperature Silicones are inherently flame-resistant Flame Resistance >10 m asdescribedinEN20811. ble ofwithstandingwater columnsof coating weightsproduce textiles capa- lowsilicone. Inaddition,evenvery ter doesnotwettextiles coated with is approx. 130°,whichmeansthatwa- of water onasmoothsiliconesurface material. Thecontactangleofadrop Silicone rubberisawater-repellent Hydrophobic, Waterproof Material

industry applications. industry must beapproved foruseinfood each individualsiliconeformulation and Polymeric Coatings.Pleasenote: (FDA) 21CFR§175.300Resinous of theFood andDrugAdministration Assessment (BfR)andrequirements the GermanFederal Institute forRisk cones meetRecommendationXVof When processed properly, manysili- Food Contact wash resistance, forexample. tic demonstrated bytheiroutstanding durableparticularly –acharacteris- making silicone-coated textiles with alarge array ofsubstrates, Silicones canformchemicalbonds Wash Resistance

Material Processing 5.5. TEXTILE COATING SILICONE PRODUCT GROUPS

ELASTOSIL® R Solid Silicone Rubber Crosslinking mechanism Peroxide curing Components 1- or 2-component systems Solvent Solvent-free; can be dispersed with solvents Viscosity Stiff pastes Curing In a drying tunnel, 150 – 200 °C, 1 – 5 min Processing Knife coating, calendering, extrusion Benefits High resistance to substances that disrupt the curing process, very good mechanical properties, high heat resistance, rapid curing

ELASTOSIL® R plus Solid Silicone Rubber Crosslinking mechanism Addition curing Components 1- or 2-component systems Solvent Solvent-free; can be dispersed with solvents Viscosity Stiff pastes Curing In a drying tunnel, 130 – 200 °C, 1 – 3 min Processing Knife coating, calendering, extrusion Benefits Rapid curing, excellent mechanical properties, dry surface

WACKER SILICONES offers you ELASTOSIL® LR Liquid Silicone Rubber a number of silicone systems that Crosslinking mechanism Addition curing differ substantially from each Components 2-component systems other in terms of processing Solvent Solvent-free; can be dispersed with solvents parameters – regardless of the Viscosity 10,000 - 500,000 mPas·s properties of the cured rubber. Curing In a drying tunnel, 130 – 200 °C, 1 – 3 min The differences lie primarily in the Processing Knife coating, dip coating application method, in the curing Benefits Very rapid curing, good processability, rate and temperature, and in the considerable formulation flexibility number of components. Each product group offers specific pro- ELASTOSIL® RD Dispersion cessing advantages tailored to Crosslinking mechanism Addition curing particular applications. Contact Components 2-component systems your technical representative to dis- Solvent Xylene or petroleum ether cuss the selection of system com- Viscosity 5,000 – 700,000 mPas·s ponents most suitable for you. Curing Evaporate solvent at no more than 100 °C and then cure for 1 – 3 min at 130 – 200 °C in a drying tunnel Processing Knife coating, dip coating Benefits Excellent mechanical properties, good processability, considerable formulation flexibility, dry surface, low coating weights possible

ELASTOSIL® E RTV-1 Rubber Crosslinking mechanism Condensation curing Components 1-component systems Solvent Solvent-free or solvent-based Viscosity 50,000 – 350,000 mPas·s Curing Skin forms at room temperature after approx. 15 min, fully cured after 1 – 3 days (dependent on atmospheric humidity) Processing Knife coating, dispensing, screen printing Benefits High resistance to substances that disrupt the curing process, easy processing, good adhesion

62 Benefits Processing Curing Viscosity Solvent Components Crosslinking mechanism ELASTOSIL ® ERTV-1 Rubber process, easyprocessing, goodadhesion High resistance to substances thatdisruptthecuring Knife coating,dispensing,screen printing humidity) fully cured after 1 – 3 days(dependent onatmospheric Skin formsatroom temperature after approx. 15min, 50,000 –350,000 mPas·s Solvent-free orsolvent-based 1-component systems Condensation curing

evenly andallowsitto permeate the blade distributes thesiliconerubber The shearforce appliedunderthe cally, infront ofadoctor blade. applied, eithermanuallyorautomati- method, liquidsiliconepastes are for applyingthinnerfilms.Inthis Knife coating,bycontrast, isideal cally 1 – 2 mm. crosslinking. Filmthicknessesare typi- pressure andthensubjected to thermal thickness, appliedto thetextile under rubber isrolled to thedesired film During thecalenderingprocess, solid to othermaterials. about anhourbefore switchingover temperature ofatleast150°Cfor heating tunnelshouldbeheldata cleaning agents.After cleaning,the as white spiritsorisoparaffins as ommend aliphaticsolventssuch Wesuch asPVCoracrylates. rec- cessing othercoatingcompounds, forprofor siliconescanevenserve - cleaning, coatingequipmentused for solidsilicones.After careful liquid siliconesandcalendering methods are knifecoatingfor ing textiles. Themostcommon mon applicationmethodsforcoat- Silicones canbeappliedbyallcom- APPLICATION METHODS TEXTILE COATING 5.5.

knife coating. obtaining excellent coatingresults by paste’s rheologyare key factors in andfine-tuning ofthesiliconeExpertise for coatingsasthinapprox. 10 µm. pressed directly onto thetextile, allowing low,is very theblade(airknife)is coating thickness.Iftheweight and thetextile definesthe resulting bond. Thedistancebetweentheblade fabric, resulting inagoodadhesive Knife Coating Calendering Liquid rubber Solid rubber Coating weight:below100g/m² Air knife: Coating weight:over500 g/m² F calender:

Coating weight:over500 g/m² Z calender: Coating weight:50–1,000 g/m² Knife overroll: Solid rubber Liquid rubber 63

Material Processing SECTION 6: SECONDARY FINISHING

64 Contents

Secondary finishing of cured silicone rubber

6.1 Post-Curing 66 When, how and why post-curing is important

6.2 Multicomponent Technologies 69 Self-adhesive silicone rubber, priming, bonding: step by step Secondary Finishing

65 6.1. POST-CURING

Ideally, silicone rubber articles do Why is Post-Curing Necessary? • Addition-curing platinum-catalyzed not need secondary finishing. But Post-curing is performed to achieve rubber: in many cases the material must be an improvement in the mechanical In this case, curing does not form post-cured. That involves heating properties (e.g. a particularly low odor containing by-products. But at a high temperature for a defined compression set), and to remove vola- post-curing is still recommended if time. tiles (by-products from the crosslinker the silicone article is intended for chemicals and low-molecular polymer use in sensitive areas, such as food- components). For e.g. food-contact contact or medical applications. In applications, post-curing is recom- such cases the relevant recommen- mended or even essential in order to dations FDA1 or BfR2 or E.P. 3.1.93 meet legal requirements. must be followed. • Peroxide-curing rubber: Post-curing serves principally to Removing Defects eliminate by-products from the Other work steps may be necessary in peroxide curing reaction. When the following cases: ELASTOSIL® AUX Crosslinker E is • Correcting flash or defects (cryogenic used, by-products migrate to the deflashing or sanding down) cured rubber surface for several • Removing sprue waste and talc hours, and can be seen as white crystal deposits on the surface Our experts will be glad to help you set (blooming). In the case of up your production plant to manufacture ELASTOSIL® AUX Crosslinker C1 products that meet your demands, and or C6, the by-products impart a eliminate unnecessary production steps, characteristic odor to the cured e.g. by means of test series in our pilot rubber, which can be removed by plant or on-the-spot advice. post-curing.

1 FDA Chapter 21 CFR § 177.2600 Rubber Articles Intended for Repeated Use. 2 BfR recommendation XV. Silicones. 3 E.P. 3.1.9: European Pharmacopeia 5.0, Chapter 3.1.9.

66 Ideally, cured ELASTOSIL® silicone rubbers are free of flash and ready to use with no further production steps

The Right Way to Post-Cure • Fresh-air supply: Carry out post-curing in a circulating- air oven with a fresh air supply. The volatile components consist predominantly of flammable low-molecular siloxanes and maybe peroxide by- products, which must be removed from the oven during post-curing. To ensure reliable operation, fresh air • Temperature/time: Important! must be supplied at a rate of 100 – Perform tests to assure the optimum Never post-cure platinum-curing grades 120 l/min/kg of silicone to prevent conditions for your part. Check the in contact with peroxides or their degra- a risk of deflagration (observe the volatiles content by measuring the dation products. The presence of such explosion limits). Most of the volatile weight loss1. The required post- substances in the ventilation air can af- components escape in the first 2 curing time increases with the layer fect the basic properties of the rubber. hours. Ensure good ventilation thickness. Sheets 2 mm thick gener- Avoid contact with volatile components of during this time. ally require 4 hours at 200 °C. The organic rubber to prevent cross contami- • Inserting the cured parts: temperature profile, too, depends on nation. Clean the post cure ovens and Place the parts on a perforated plate the thickness of the parts: the thicker exhaust system regularly, and replace the or wire mesh, if possible without their the part the lower the starting tem- pipes in certain intervals. touching each other, so that they perature and the slower the tempera- are not deformed by their inherent ture is increased. Following the heat- weight. To avoid unrestricted air flow, ing-up phase, post-curing should be do not place parts one inside the conducted for at least 4 hours at other. Coil up tubes or profiles. 200 °C. Never exceed 220 °C or a In the production of cables, the cable post-curing time of 8h, since this can drums should be wound loosely. Sin- lead to undesirable thermal aging of gle rods between the layers ensure the material and embrittlement. that air can circulate through the Besides thermal aging, an oxygen Secondary Finishing cable drum. deficiency can also cause undesirable reversion (degradation of crosslinks) and the formation of unwanted form- aldehyde. Check regularly that the oven is operating at constant conditions (e.g. constant temperature).

1 BfR tests require drying over calcium chloride prior to weight loss determination.

Picture: ©Eberl Trocknungsanlagen GmbH

67 Influence of Post-Curing Time on Compression Set of ELASTOSIL® LR 3003/50 at Various Wall Thickness

40 Compression set* [%] set* Compression

0 0 1 2 3 4 5 6 7 Time/temperature at 200 °C [h]

■ Wall thickness 6 mm ■ Wall thickness 2 mm

* Measurement of compression set at 22h/175 °C in compliance with DIN ISO 815-B

Post-Curing for Technical ELASTOSIL® AUX Crosslinker E Applications and Stabilizer R Post-curing can also be used to • Many HTV extrusion grades (e.g. for achieve particular technical properties. window profiles) do not need to be For example, the compression set of post-cured if Stabilizer R is added to ® cured ELASTOSIL silicone rubber the silicone rubber. The stabilizer pre- depends very significantly on the post- vents the blooming of by-products in ® curing time. In the case of ELASTOSIL ELASTOSIL® AUX Crosslinker E and LR 3003/50, non-post-cured products improves the compression set. have a compression set of 60 – 70%, • Large-volume parts require post-curing which can be improved by post- and the addition of Stabilizer R. curing. The non-post-curing grades Here, incomplete migration of dichloro- ® ® ELASTOSIL LR 3005, ELASTOSIL benzoic acid, a primary by-product ® LR 3015, ELASTOSIL LR 3065 and of ELASTOSIL® AUX Crosslinker E, ® ELASTOSIL R 701 are designed for a chemically ages the rubber by acid at- particularly low compression set even tack from the rubber bulk (softening it). without post-curing. However, they are Stabilizer R binds the by-products and generally restricted to use in technical significantly restricts this reaction. applications.

68 6.2 MULTICOMPONENT TECHNIQUES

Hard-Soft Combinations with Silicones

Mechanical interlocking (undercut)

Chemical bonding using primers

Chemical bonding using silicone rubber

Substrate Silicone rubber Primer

Silicone rubber can bond either Chemical Bonding Techniques Advantages of Chemical Bonding mechanically or chemically to other Chemical bonding techniques include: Chemical bonding generally offers substrates. The mechanical bond is • Use of self-adhesive silicone rubber price and performance advantages: produced by interlocking, for exam- • Vulcanizing onto a primer-treated • Lower mechanical loading ple by overmolding of openings or substrate • Lower tendency of the bond to undercuts in the hard component. • Bonding of premolded individual fatigue Chemical bonding generally offers parts • Lower weight several advantages: there are • Physical (e.g. plasma) or mechanical • Bonds and seals simultaneously various ways of achieving this. treatment of the substrate surface • Can be bonded to shock-sensitive

substrates (e.g. glass) Secondary Finishing • Can be bonded to electrochemically sensitive metals

69 6.2 MULTICOMPONENT TECHNIQUES SELF-ADHESIVE SILICONE RUBBER

Self-adhesive silicone rubber Advantages grades such as ELASTOSIL® The advantages of self-adhesive R plus 4070 or ELASTOSIL® LR silicone rubbers ELASTOSIL® R plus 3070 adhere directly to a substrate and LR are especially clear: during vulcanization. • Only one step (no application of primer, no cleaning of the substrate, Adhesion to metals such as steel, no undercuts) aluminum or brass is generally very • Rapid curing and therefore short good. The same applies to many ther- contact time with the mold moplastics and thermosets. Silane- • Easily demoldable, even from based products are generally used in uncoated steel the rubber as internal adhesion pro- • Rapid build-up of adhesion strength moters. They are compatible with the to the substrate uncured rubber but incompatible with • No adhesion to the mold the cured rubber, and therefore diffuse to the surface during vulcanization, Please Note forming a chemical bond. • Always check that the silicone rubber is compatible with the substrate (metal, Injection Molding Injection molding machine for 2K materials glass, PA, PBT, PET, etc.) The following processing methods can • The melting point of the substrate be used here (for details, see section 5, should be as high as possible pages 56 – 57): • Extensive information about tested ma- • Insertion process terial combinations and adhesion values • 2K process on an injection molding is available from our technical service. machine We will be pleased to perform tests in – Mold with rotary table house on your behalf – Transfer within the mold by a handling robot • 2K injection molding process with two IM machines – Two different molds linked via a handling robot

Extrusion For extrusion applications, coextrusion can be used to produce extrudates from different materials in one step (for details, see section 5, page 46).

70 6.2 MULTICOMPONENT TECHNIQUES PRIMER/ADHESIVE

Primers Primer Dynamic viscosity Special Suitable for Recommended in mPa •s Characteristics coating technique WACKER® PRIMER 1 General purpose Platinum curing rubber Spraying G 790 WACKER® PRIMER 1 General purpose Platinum curing rubber Spraying G 790 TOLUENE FREE WACKER® PRIMER 4000 Silicone-on-silicone Platinum curing rubber Brushing or dipping G 791 A+B curing ELASTOSIL® AUX 5 General purpose Peroxide curing rubber Spraying G 3242 ELASTOSIL® AUX 550 General purpose Peroxide curing rubber Spraying or brushing G 3243 ELASTOSIL® AUX 300 Red color Peroxide curing rubber Spraying or brushing G 3244 ELASTOSIL® AUX 2600 General purpose Peroxide curing rubber Brushing or dipping G 3246

ELASTOSIL® AUX PRIMERS G serve Application • Dry primed metal parts in air for at as adhesion promoters between sili- ELASTOSIL® AUX PRIMERS G are least 15 minutes. cone elastomers and other substrates used to pretreat metallic, ceramic, • Store the pretreated surfaces in like metals, glass and thermoplasts. glass or other polymeric substrate a clean and dust-free place for ELASTOSIL® AUX PRIMERS G are surfaces to enable excellent adhesion maximum 24 hours drying time. solvent based and contain a mixture of towards subsequent vulcanized • So that the primer film is not dam- reactive silanes and siloxanes. ELASTOSIL® R, R plus or LR silicone aged by high shearing forces during elastomers. vulcanization, in the case of large- Special Characteristics area coatings and for the production • Provide excellent adhesion onto vari- Step by Step of rollers or rubberized metal parts ous substrates. • The substrate to be primed must be by injection molding, the primer Secondary Finishing • Solvent based – Different viscosities dry and free of grease, oils or other should be baked in the press. available for various coating tech- contaminants. Very smooth surfaces For example: 20 to 40 minutes at niques like dipping, brushing or must be roughened, for example 100 to 140 °C. spraying. thoroughly cleaned by sandblasting • Further dilution in organic solvents or with glass beads, and degreased possible. with solvents such as white spirit or Please Note acetone. Primers are based on moisture-sensitive • Apply primer by spraying, dipping or compounds. Therefore, only open the brushing (thin coat with no bubbles). containers briefly during processing and For absorbent surfaces, repeat prim- do not return residues to the vessel. ing several times

71 6.2 MULTICOMPONENT TECHNIQUES BONDING OF PREMOLDED INDIVIDUAL PARTS

Adhesive Two-Component Systems Adhesive Dynamic viscosity Special Characteristics Two-component systems (RTV-2) are in mPa•s (Brookfield) an economically attractive alternative ELASTOSIL® E43 350.000 General purpose for larger production runs and large- ELASTOSIL® E43 N 300.000 For food contact applications area bonds. They cure rapidly even un- ELASTOSIL® E47 Non-slump Fast curing at elevated temperatures der lower air exposure. ® ELASTOSIL N10 10.000 General purpose • Step by step: ® ELASTOSIL N199 Non-slump General purpose – Apply the paste thinly to the ® SILPURAN 4200 300.000 For medical applications cut surface and fix the bond in position under pressure WACKER supplies one and two- • Step by step: – Cure by direct heating, with a component room-temperature- – Clean the rubber parts or hot-air gun or in a drying cabinet curing systems for bonding substrate carefully and degrease – The time depends on the heating vulcanized silicone rubber parts if necessary method and thermal capacity of or bonding silicone rubber to – Apply the silicone rubber 1-com- the parts to be bonded. At about other substrates. ponent adhesive (RTV-1) to a thick- 170 °C, the bond cures within ness of at least 0.5 mm 20 to 30 seconds One-Component Adhesive – Miter cut the ends of cords or One-component room-temperature- profiles obliquely before bonding to Bonding of Metal vulcanizing (RTV-1) silicone rubber give the biggest possible bonding • ELASTOSIL ® E one-component silicone compounds are supplied ready to area rubber compounds release acetic acid process in tubes, cartridges and pails. – Press together the parts to be when they cure causing corrosion to The compounds cure on exposure to bonded and fix them in position some metals atmospheric moisture. ELASTOSIL® until the adhesive has cured • Therefore, pretreat metals with primer G E 43 N is a solvent-free, heat-resistant – Depending on the air humidity, the 790; the primer also improves adhesion transparent adhesive that does notuse optimum bond strength at room • With very corrosion-sensitive metals, tin-containing catalysts. ELASTOSIL® temperature is achieved within we recommend using amine-curing or E 41 is a toluene-containing one- 12 to 15 hours. It is much faster neutral systems component dispersion that is easier to at temperatures between 50 and handle due to its improved flow prop- 100 °C and high humidity erties. However, ELASTOSIL® E 43 N is better for large-area bonding of relatively thin silicone rubber parts. The warping caused by the swelling effect of toluene can be avoided in this case.

72 73

Secondary Finishing SECTION 7: SERVICE

74 SECTION 7: SERVICE

Contents

How we support you along the entire process chain

7.1 Technical Support and Advice 76 Technical centers, pilot plant and applications labs

7.2 SILMIX® 78 Ready-to-use silicone compounds to your specifications

7.3 WACKER Infoline / E-Business 79 The direct route to the righ contact/tailored solutions from electronic ordering to the vendor managed inventory

7.4 Regulatory Support 80 Qualified support in approval procedures according to national and international standards

7.5 WACKER ACADEMY 81 Seminar and training programs covering the world of silicone rubber Service

75 7.1. TECHNICAL SUPPORT AND ADVICE

What We Offer • Preliminary material selection tests • Production of two-component samples especially for adhesion testing and other test purposes • Extruding profiles, tubing, round strands, cables of different geometries and silicone rubber materials for test purposes • In-site production of prototypes and sample series using the client’s own tooling for screening tests, approval or subsequent use by the end customer • Joint development of specific products • Training and instruction • System consulting, particularly process design and utilization of machines/tooling in new applications and projects • In-site process optimization • Analysis and simulation of problems We offer you technical support at For example, our pilot plant in occurring in processing and various levels to ensure the success Burghausen forms the interface between production of our products at every stage in product and applications expertise. It • Individual problem solving and your process chain. is equipped with a lab and test facili- ensuring process stability ties, as well as production systems Technical Centers (extrusion and injection molding) for We maintain technical centers in all key HTV and LSR silicone rubber, and regions to assist you in any technical 2K combinations. At our pilot plant, matters. From adjusting formulations we put our ELASTOSIL® product se- to individual requirements, to property ries through a range of practical tests testing of rubber compound and cured as part of their development, testing, material. The technical centers are modification and optimization. At the equipped to perform all relevant ana- same time, we offer extensive advice lytical techniques and lab tests for you at every step in the supply chain, and according to international and local put our pilot plant and all the necessary standards and regulations. You have tools at your disposal. Or we work access not only to our locally based on your premises at your production experts but also to our globally net- plant. worked knowledge from over 50 years of market experience.

76 Applications Labs Some of Our Services For technical support, our application • Technical consultancy for product chemists work closely with our cus- selection to your specific requirements tomers, dealing with specific questions • Joint development of specific from the field. We will support you by products finding the optimum product for your • Testing the chemical resistance of specific requirements and supporting materials your product development from mate- • Thermal storage tests rial selection through to industrial pro- • Providing samples and sheet samples duction – worldwide. Our laboratories • Color matches deal with key issues from specific in- • Advice on questions about material dustrial sectors (such as medical and processing automotive applications and cables). They have thereby built up special expertise and know-how in these Service application fields.

77 7.2. SILMIX®: CUSTOM SILICONE RUBBER COMPOUNDS

Best Quality SILMIX® compounds are manufactured to the same quality standards as all WACKER silicone rubber grades. Thanks to its integrated silicon production system, WACKER is highly backward-integrated and produces the necessary raw materials itself, from the polymer base upwards. This ensures highly consistent good quality.

With SILMIX®, we offer you ready- Flexible and Globally Represented Interested? ® to-use silicone rubber compounds At our SILMIX plants at various sites You can find further information on our tailored to your specifications. around the world, we develop custom website: www.wacker.com/silmix compounds to your specifications.

Direct and Versatile Our ready-to-process SILMIX® products allow you to manufacture a wide variety of silicone rubber articles directly by various processes, such as pressing, transfer molding, injection molding and extrusion. Applications range from automotive gaskets, through cable insulation, to rubber-coated rolls for photocopiers.

78 7.3. WACKER INFOLINE E-BUSINESS

Infoline E-Business To make it easier for you to get into WACKER e-solutions simplify commu- rapid personal dialog, we have set up nication with customers and suppliers, an info hotline for you. For all ques- and offer many new possibilities: from tions concerning silicone rubbers from global searches to expedited order WACKER, our products and services, processing via the web platform or just call us or send us an email: you Hub2Hub, to vendor managed inven- will be redirected to a specialist who tory – just as you wish. We compile a can answer your questions. tailored service package for you. Exactly tailored to the size of your Europe and the Middle East company, your profile and the wishes • Infoline Germany: of each contact. 0800 – 6279 – 800 • International Infoline: You can gain considerably greater +49 89 6279-1741 efficiency through: • Email: [email protected] • “Clean orders” • Fewer order changes NAFTA region – • Faster processing with a greatly Canada, Mexico and USA reduced proportion of errors • Infoline: • Maximum planning reliability and +1 888 -922-5374 • Full transparency (+1 888-WACKER 4 U) • Email: [email protected] WACKER e-solutions support you exactly where human error is most common. However, they supplement rather than replace human interactions, And you can by bringing the right people together. • Call up any industry and product Our partners value the direct line to information you want our experts in R&D, supply chain man- • Order easily, quickly and agement, sales support and technical reliably – 24/7 customer service. • Carry out paperless invoicing • Automatically process all orders • Automatically check and complete your inventories Service

79 7.4. REGULATORY SUPPORT

To ensure product safety, we – of • Requirements of specific industries Just Ask Us! course – offer you regulatory support. (e.g. GADSL, IMDS, automotive Call us if you have any questions about Our experts will deal with your enqui- industry) food approvals, REACH or other regulatory ries about environmental, health and • Specific customer requirements issues. Please ask our sales managers regulatory matters. (e.g. banned-substance and first, who are your direct contacts. They substance-avoidance lists) will pass your questions on to our experts This includes, for example, the • Toxicology and ecotoxicology and send you our reply to your specific following topics: • Risk assessment question! • Food contact applications • Organizational assistance (e.g. BfR, FDA) • Drinking water approval (e.g. KTW, WRAS, ACS) • Pharmaceutical and medical applications (e.g. European Pharmacopeia and U.S. Pharmacopeia USP) • National and international regulations and provisions (e. g. EU directive 2002/95/EC – RoHS, REACH)

80 7.5. THE WACKER ACADEMY

To transfer its own expertise and mar- You can find the current program at: All our seminars are held by experi- ket experience, WACKER has founded www.wacker.com/wacker-academy. enced specialists – chiefly in-house a unique institution, the WACKER The WACKER ACADEMY is headquar- experts. To make our program even ACADEMY. Here, at a number of sites tered at our largest production plant, more attractive and ensure it remains worldwide, you can take advantage of which is in Burghausen, Germany. up to date, we work closely with a versatile, industry-specific seminar Further WACKER ACADEMY centers universities and research institutes. program. located in different regions exemplify our policy of making global expertise This includes: available right on your doorstep. As a • Introductory chemistry seminars result, we can offer you a seminar pro- • Training programs on particular gram that is tailored to you and your application fields specific markets. • Introductory seminar on silicone rubber for newcomers to the field

• General seminars, e.g. on intercul- Service tural communication or innovation management

81 SECTION 8: RUBBER SOLUTIONS A–Z FACTS AND FIGURES ABOUT SILICONE

82 Weathering andUVresistance Water andsteam resistance Volume resistivity Tracking Resistance Thermal conductivityandspecificheatcapacity Temperature behavior Tear strength andelongationatbreak Tear propagation andnotchresistance resistanceSurface Shrinkage 86 Solvent andchemicalsresistance Reversion 85 Rebound resilience Ozone resistance Hot-air resistance High-energy radiation Hardness 85 Gas permeability Flame resistance Fire behavior Dissipation factor Dielectric strength Dielectric constant Density 84 Compression set Coefficient of expansion A listoffrequently usedtechnical terms isgivenbelow. Contents 87 87 87 87 87 87 86 86 86 86 85 85 85 85 85 84 84 84 84 84 84 84 83

Rubber Solutions A-Z 8. RUBBER SOLUTIONS A–Z FACTS AND FIGURES ABOUT SILICONE

Coefficient of Expansion (Linear) Density Fire Behavior • Linear thermal coefficient of silicone • Determination as per ISO 1183-1 A • The auto-ignition temperature of rubber is approx. 2 – 4 ∙ 10-4 ∙ K-1 (buoyancy method). cured products is about 430 °C. • Shrinkage of the final parts needs • Typical range for specific density • Silicone rubber burns to form a white to be taken into consideration. 1.05 – 1.60 g/cm³. non-toxic ash of silicon dioxide • Tool steel approx. 1.5 ∙ 10-6 ∙ K-1. • When using additional inactive fillers • The resultant combustion gases are (e.g. quartz), values up to 1.75g/cm3 usually non-corrosive. Compression Set can be achieved, e.g. to improve • Specialty grades for high-safety • Determination of the compression swelling resistance. cables form a ceramic layer in the set as per ISO 815-B (ASTM D395 case of fire. B-2) by storage for 22h/175 °C, or Dielectric Constant ε 22h/125 °C in the case of self- • Determination of dielectric constant ε Flame Resistance adhesive grades. as per DIN 53 482 or VDE 0303. • Determination of the flame resistance • Compression set describes the elas- • Typical values for silicone rubber: acc. to test standard ASTM D 2863 tic recovery of a cured rubber, an ε = 2.7 - 3.3 (at 25 °C and 50 Hz). by determining the limiting oxygen important characteristic for gasket • This property can be increased up index (LOI) or acc. to Underwriters applications. to 150 by the use of suitable fillers. Laboratory fire standard (UL 94). • Typical values for silicone rubber: • Typical LOI values of flame retardant 5 – 25%. Dielectric Strength grades 27 to 35% • Determination of dielectric strength • Standard grades normally achieve per IEC 60243-1. UL 94 HB (0.5 – 1.0 mm thickness*) • Typical value for ELASTOSIL® • Specialty grades with additives silicone rubber > 20 kV/mm reach UL 94 V0 (0.75 – 4.0 mm (measured on a 1 mm sheet). thickness*). • In the case of solid silicone rubber, Dissipation Factor Tan δ the addition of 2.2% ELASTOSIL® • Determination of the dissipation AUX Batch SB-2 improves the flame factor as per VDE 0303. resistance considerably. • Typical values for loss angle tan δ ~ 10–3. tan δ is raised by increasing the filler content/density.

* dep. on grade

84 Gas Permeability High-Energy Radiation • For selected products of the • Determination as per DIN 53 536 • Outstanding resistance of silicone ELASTOSIL® R 401 and • Very high gas permeability compared rubber (VMQ, PVMQ) to high-energy ELASTOSIL® LR 3003 series, a to other elastomers, e.g. for air 30 radiation in combination with hot-air cracking level of 0 was obtained af- times higher than for natural rubber resistance in comparison to other ter 96h at an ozone concentration of (NR) or 400 times higher than butyl elastomers. 200 pphm (temperature: 40 °C, r.h. rubber (IIR) (measured at 25 °C) • With VMQ silicone rubber grades, 55%, elongation 80%) • The absolute value of a 50 Shore A only high radiation doses of 400 – grade for air at 20 °C and 80 °C is 800 kGy lead to a reduction of 50% Rebound Resilience 570 and 1.330 cm3 ∙ mm ∙ m-2 ∙ h–1 ∙ in the elongation at break. • Determination of rebound resilience bar–1 (volume of air measured in cm3, • Phenyl-containing PVMQ silicone as per DIN 53 512 that penetrates a membrane of 1 m2 rubber, such as ELASTOSIL® R • Also commonly known as “snap” area per hour at a pressure difference 490/55, has higher resistance. • Measured on 6 mm samples as a of 1 bar and 1 mm thickness) • Properties not severely affected by ratio of rebound height to the drop • Technical advantage, e.g. for contact gamma and beta radiation height of a pendulum lenses, textile coatings and for some (25 – 75 kGy), as widely used for • Typical values 30 – 70%. medical applications sterilization of medical equipment. • At high temperatures, silicone has • Very good resistance to microwaves, Reversion similar values to organic elastomers since silicone parts are not microwave- • By reversion is meant in general deg- active and therefore not heated. radation of the crosslinking network in the cured rubber as a result of Gas Permeability Hot-Air Resistance chemical or thermal effects, which Gas relative permeability • The mechanical properties of leads to a permanent decrease of at 25 °C [%] Air 100 WACKER silicone rubber are retained hardness (softening) Hydrogen 190 even at high temperature loading • In silicone rubber, at high tempera- Oxygen 170 (hot air). tures (> 200 °C) traces of moisture Nitrogen 80 • As a result, the hot-air resistance is or free hydroxyl groups in fillers Carbon dioxide 1.000 clearly superior to that of most organic cause cleavage of the Si-O bond in Ethylene 390 elastomers (cf. ASTM Chart D2000) the polymer chain and ultimately the above-mentioned decrease in hard- Hardness Ozone resistance ness due to depolymerization • Determination of the hardness of • Outstanding resistance of silicone • This process is inhibited by the pres- silicone rubber in Shore A (ISO 48-4) rubber to ozone ence of air or in IRHD units (DIN 53 519). • Determining ozone resistance as per • High heat resistance therefore re- • Typical bandwidth 3 – 90 Shore A. DIN 53509 quires unrestricted access of atmospheric oxygen • In the case of thick parts, where oxygen diffusion is difficult, this process is inhibited by the use of Stabilizer R.

85 Rubber Solutions A-Z Solutions Rubber Solvent and Chemical Resistance Shrinkage Tear Strength and Elongation • The chemical resistance of WACKER • Linear shrinkage of approx. 2 – 4% at Break silicone rubber generally depends on falls with increasing Shore hardness • Determination as per DIN 53 504 the crosslinking density, filler used, and lower vulcanization temperature • Standard test on S1 bar. In excep- and filler content. • The higher the filler content or den- tional cases also measurements on • With higher filler levels in the silicone sity, the less is the shrinkage of the small S2 and S3 test specimens, rubber, swelling tendency decreases cured parts. though the values deviate and resistance is therefore improved. • Very strong dependency on pro- correspondingly • High swelling tendency to non-polar cessing parameters and material • Typical values for tensile strength: liquids such as hydrocarbons, grades approx. 5 – 12 N/mm2 (or MPa) mineral oils and greases. • For precision parts, fine tuning is • Typical values for elongation at • Low swelling tendency to polar necessary by means of preliminary break: approx. 100 – 1.100% liquids, such as polyhydric alcohols, tests. low-molecular ketones, and therefore no negative effect on seal quality. Surface Resistence • Strongly attacked by concentrated • Determination of the surface acids and alkalis, particularly by resistivity per VDE 0303 oxidizing acids such as sulfuric or • Typical values for insulating nitric acid. ELASTOSIL® LR compounds: • Silicone rubber has good resistance approx. 1012 – 1013 Ω. to aqueous solutions of weak acids, alkalis or salts, which are commonly Tear Propagation and Notch used as cleaning solutions for lines/ Resistance tubing at 70 – 80 °C in the food • Tear strength depends on which industry. particular standard is used. • Typical values when determined as per ASTM D 624 B (crescent): 5 – 55 N/mm. • Values are up to 30% lower when measured by ISO 34-1, method B-b (Graves). • ISO 34-1 method A (trouser) yields values about 50% lower.

86 • • • • • • • • Temperature Behavior produces quartz-like properties. obtained, asoxidative degradation for insulationathightemperatures is Excellent stablelong-term behavior ers H1–H6orofFLpigmentpastes. increased bytheuseofheatstabiliz- The lifetimeofthevulcanizate canbe the vulcanizate leads to shrinkage. The simultaneousweightdecrease of (embrittlement). strength andelongationatbreak together withadecrease oftensile chains, withanincrease inhardness cause post-curingofthepolymer cleavage. Theresulting free radicals the siliconatom undergo free-radical the organic sidegroups attachedto At hightemperatures ( ible crystallization. temperatures (–40°C)dueto revers- The material hardens low atvery –50 to +250°C. Typical temperature service range: organic elastomers. ASTM D2000. properties isonlysmallcompared to The changeinthemechanical respectively. as perDIN53503or53505 elastomers determined at23°C(RT) Mechanical properties ofsilicone > 180°C),

• • • • • Heat Capacity Thermal ConductivityandSpecific • • Volume Resistivity • Tracking Resistance • • systems. grades compared to peroxide-cured in thecaseofplatinum-catalyzed Lower temperature dependency approx. 2-150Ω∙cm. Typical valuesforconductive grades approx. 0.2–0.3W∙m Typical valueat100°C: the typeandamountoffillersused. The thermalconductivitydependson Determined asperDIN52612 rubber grades approx. 10 Typical valuesforinsulating silicone Determination asper VDE0303 (CTI: 600-<1asperIEC60112). high tracking resistance Silicone rubbergenerally features 0.1 – 1.2 W∙m compounds achievevaluesofabout Special thermallyconductive pacity: approx. 1.25kJ∙kg Typical valuesforspecific heatca- -1 ∙K -1 . -1

∙K 15 Ω∙cm. -1 -1 ∙K

. -1 . • • • Weathering andUVResistance • • • Water andSteam Resistance etc.). sorganic antioxidants, UVstabilizers, achieved withoutadditives(e.g. weathering resistance canbe Unlike with organic elastomers, weathering). in long-term tests (several yearsof Properties onlychangeslightlyeven insensitive to UVradiation. areSilicone rubberarticles generally properties. slight worseningofmechanical at 134°C,5min.)leadsto onlya 17665, DINEN868-8at500cycles Steam sterilization (asperISO low 1%,evenafter prolonged action. Volume decrease inboilingwater be- Excellent resistance to boilingwater.

Rubber Solutions A-Z YOUR NOTES

EXPERTISE AND SERVICE NETWORK ON FIVE CONTINENTS

SalesVertriebs- offices, und production Produktionsstandorte sites and technical sowie competence centerstechnische around Kompetenzzentren the world. weltweit

WACKER is one of the world’s leading Spanning the globe with 4 business customers worldwide in the develop- and most research-intensive chemical divisions, we offer our customers highly- ment of products tailored to regional companies, with total sales of €4.69bn. specialized products and comprehensive demands, supporting them during every Products range from silicones, binders service via 26 production sites, 23 techni- stage of their complex production pro- and polymer additives for diverse industrial cal competence centers, 14 WACKER cesses, if required. sectors to bioengineered pharmaceutical ACADEMY training centers and 52 sales WACKER e-solutions are online services actives and hyperpure silicon for semi- offices in Europe, North and South America, provided via our customer portal and as conductor and solar applications. As a and Asia – including a presence in China. integrated process solutions. Our custom- technology leader focusing on sustainability, With a workforce of some 14,300, we see ers and business partners thus benefit WACKER promotes products and ideas ourselves as a reliable innovation partner from comprehensive information and that offer a high value-added potential to that develops trailblazing solutions for, reliable service to enable projects and ensure that current and future generations and in collaboration with, our customers. orders to be handled fast, reliably and enjoy a better quality of life, based on We also help them boost their own suc- highly efficiently. energy efficiency and protection of the cess. Our technical competence centers Visit us anywhere, anytime around the climate and environment. employ local specialists, who assist world at: www.wacker.com

All figures are based on fiscal 2020.

E_de_single page_A4_2021_200421_RZ.indd 1 20.04.21 11:22 CREATING TOMORROW’S SOLUTIONS

Wacker Chemie AG PRODUCT OVERVIEW 09.19

Hanns-Seidel-Platz 4 / 81737 Munich, Germany Phone +49 89 6279-1741 www.wacker.com/contact www.wacker.com Follow us on: PEROXIDE-CURING 05.21 replaces 6709C e /

6709C e SOLID SILICONE RUBBER

Multi-purpose · High green strength · High tear resistance · Low compression set

These figures are only intended as a guide and should not be used in preparing specifications.

1 BfR recommendation XV (silicones); (BfR = Bundesinstitut für Risikobewertung). 2 FDA CFR 21 § 177.2600 ”Rubber articles intended for repeated use“ (FDA = Food and Drug Administration). 3 Categories on request. 4 Non-postcured Please contact us for in-depth technical consulting to select the right product for your individual demands. Please contact us if you are interested in products with specific characteristics or if you need products from our basic portfolio in other hardnesses.

ELASTOSIL® is a registered trademark of Wacker Chemie AG. CREATING TOMORROW’S SOLUTIONS

Wacker Chemie AG PRODUCT OVERVIEW Hanns-Seidel-Platz 4 81737 Munich, Germany Phone +49 89 6279-1741 www.wacker.com/contact www.wacker.com Follow us on: PEROXIDE-CURING

6709D e/05.21 replaces 6709D e/09.19 SOLID SILICONE RUBBER

Media resistant · High rebound resilience · Low temperature resistance · High heat resistance · Ceramifying · Electrically conductive · Flame retardant · Low rebound resilience · Superheated steam resistance ·

The data presented in this medium are in accordance with the present state of our knowledge but do not absolve the user from carefully checking all supplies immediately on Magnetisable receipt. We reserve the right to alter product constants within the scope of technical progress or new developments. The recommendations made in this medium should be checked by preliminary trials because of conditions during processing over which we have no control, especially where other companies’ raw materials are also being used. The information provided by us does not absolve the user from the obligation of investigating the possibility of infringement of third parties’ rights and, if necessary, clarifying the position. Recommendations for use do not constitute a warranty, either express or implied, of the fitness or suitability of the product for a particular purpose. Main characteristics Brand Product Hardness Specific gravity Tensile strength Elongation at Tear resistance Compression set Data obtained Food contact - Food contact – Drinking water Drinking water Molding Extrusion Appearance Typical applications Shore A [g/cm 3] [N/mm 2] break [%] [N/mm] ASTM D [%] (22 h/175 °C) with curing BfR 1 FDA 2 contact – contact – ISO 48-4 ISO 1183-1A ISO 37 Typ 1 ISO 37 Typ 1 624 B DIN ISO 815-B agent KTW 3 WRAS Media resistant ELASTOSIL® R 700/40 4 42 1.09 7.3 470 14 10 C1 X X X Translucent Production of industrial molded parts, e.g. rollers or seals and gaskets in contact with oil ELASTOSIL® R 700/80 4 83 1.39 6.2 200 16 17 C1 X X X Beige Production of industrial molded parts, e.g. rollers or seals and gaskets in contact with oil ELASTOSIL® R 701/40 41 1.10 6.9 460 14 7 C1 X Opaque Production of industrial molded parts, e.g. rollers or seals and gaskets in contact with oil ELASTOSIL® R 701/50 51 1.16 7.8 470 20 7 C1 X Beige Production of industrial molded parts, e.g. rollers or seals and gaskets in contact with oil ELASTOSIL® R 701/60 61 1.24 7.6 340 16 6 C1 X Beige Production of industrial molded parts, e.g. rollers or seals and gaskets in contact with oil ELASTOSIL® R 701/70 71 1.30 7.8 280 17 7 C1 X Beige Production of industrial molded parts, e.g. rollers or seals and gaskets in contact with oil ELASTOSIL® R 701/80 81 1.39 7.6 200 16 17 C1 X Beige Production of industrial molded parts, e.g. rollers or seals and gaskets in contact with oil ELASTOSIL® R 780/80 oH 80 1.74 6.0 70 8 15 E X X X Beige Masterbatch for compounding inert fillers ELASTOSIL® R 861/60 S 57 1.16 8.5 370 20 21 E X X X Translucent Production of extruded or molded parts, e.g. seals with low compression set ELASTOSIL® R 861/70 S 69 1.20 8.8 320 20 29 E X X X Translucent Production of extruded or molded parts, e.g. seals with low compression set High rebound resilience ELASTOSIL® R 101/25 oH 23 1.07 7.0 890 14 13 C1 X X X Translucent Production of molded parts, e.g. damping elements ELASTOSIL® R 101/35 oH 35 1.09 8.0 700 16 10 C1 X X X Translucent Production of molded parts, e.g. damping elements for engine mounts ELASTOSIL® R 101/45 oH 47 1.10 8.0 540 18 10 C1 X X X Translucent Production of molded parts with excellent long-term stress durability, e.g. damping elements for engine mounts ELASTOSIL® R 101/65 oH 65 1.13 8.0 200 16 10 C1 X X X Translucent Production of molded parts with excellent long-term stress durability, e.g. damping elements for engine mounts Low temperature resistance ELASTOSIL® R 490/55 oH 50 1.17 11.0 500 33 39 E X X X Transparent Production of extruded or molded parts with very good low temperature resistance High heat resistance ELASTOSIL® R 750/40 oH 40 1.12 10.5 600 23 26 E X Transparent Production of extruded parts with good resistance to dry heat ELASTOSIL® R 750/50 oH 49 1.14 10.8 530 28 20 E X X Translucent Production of extruded parts with good resistance to dry heat ELASTOSIL® R 756/40 oH 41 1.10 8.0 570 21 8 C1 X X X Transparent Production of molded parts with good resistance to dry heat ELASTOSIL® R 756/50 oH 51 1.13 9.5 510 24 10 C1 X X Transparent Optimized for high temperatures ELASTOSIL® R 756/60 oH 58 1.15 10.0 460 25 12 C1 X X X X Transparent Extruded or molded parts with excellent heat resistance ELASTOSIL® R 756/70 oH 67 1.18 10.0 430 26 11 C1 X X X X Transparent Extruded or molded parts with excellent heat resistance Ceramifying. ash-stable ELASTOSIL® R 502/75 oH 73 1.28 8.7 400 24 56 C6 X White Production of safety cables ELASTOSIL® R 512/70 oH 70 1.37 6.5 314 18 41 E X White Production of safety cables ELASTOSIL® R 570/50 oH 52 1.11 7.9 370 14 37 C1 X Black Production of electrically conductive molded parts (volume resistivity 6.2 Ω cm) ELASTOSIL® R 570/60 oH 62 1.13 7.4 230 12 29 C1 X Black Production of electrically conductive molded parts (volume resistivity 3.5 Ω cm) ELASTOSIL® R 570/70 oH 71 1.15 7.4 180 12 34 C1 X Black Production of electrically conductive molded parts (volume resistivity 3.7 Ω cm) Flame retardant ELASTOSIL® R 501/75 oH 68 1.23 7.3 500 34 E X White Applications with high demands on fire safety, e.g. door profiles in trains or floor profiles in airplanes ELASTOSIL® R 770/50 oH 46 1.14 9.0 670 38 16 E X White Applications with high demands on fire safety, e.g. door profiles in trains or floor profiles in airplanes ELASTOSIL® R 770/60 oH 63 1.49 4.0 420 14 38 E X White Applications with high demands on fire safety, e.g. door profiles in trains or floor profiles in airplanes ELASTOSIL® R 770/75 oH 72 1.55 3.8 350 15 39 E X White Applications with high demands on fire safety, e.g. door profiles in trains or floor profiles in airplanes Low rebound resilience ELASTOSIL® R 752/50 oH 50 1.18 9.9 770 32 38 C1 X X X Translucent Production of molded parts with good damping properties, e.g. vibration damping elements in the automotive industry ELASTOSIL® R 752/70 oH 70 1.22 8.5 460 22 19 C1 X X X Translucent Production of molded parts with good damping properties, e.g. vibration damping elements in the automotive industry Superheated steam resistance ELASTOSIL® R 755/60 oH 60 1.18 7.7 330 17 16 C1 X Opaque Production of molded parts with good resistance to steam Magnetisable ELASTOSIL® R 781/80 83 2.33 3.3 50 18 64 E X X X X Black Production of magnetic profiles

These figures are only intended as a guide and should not be used in preparing specifications.

1 BfR recommendation XV (silicones); (BfR = Bundesinstitut für Risikobewertung). 2 FDA CFR 21 § 177.2600 ”Rubber articles intended for repeated use“ (FDA = Food and Drug Administration). 3 Categories on request. 4 Non-postcured Please contact us for in-depth technical consulting to select the right product for your individual demands. Please contact us if you are interested in products with specific characteristics or if you need products from our basic portfolio in other hardnesses.

ELASTOSIL® is a registered trademark of Wacker Chemie AG. CREATING TOMORROW’S SOLUTIONS

Wacker Chemie AG PRODUCT OVERVIEW 09.19

Hanns-Seidel-Platz 4 / 81737 Munich, Germany Phone +49 89 6279-1741 www.wacker.com/contact www.wacker.com Follow us on: LIQUID SILICONE RUBBER 05.21 replaces 6709E e /

6709E e Multi-purpose · High tear resistance · Media resistance · Heat resistance · Low coefficient of friction

The data presented in this medium are in accordance with the present state of our knowledge but do not absolve the user from carefully checking all supplies immediately on receipt. We reserve the right to alter product constants within the scope of technical progress or new developments. The recommendations made in this medium should be checked by preliminary trials because of conditions during processing over which we have no control, especially where other companies’ raw materials are also being used. The information provided by us does not absolve the user from the obligation of investigating the possibility of infringement of third parties’ rights and, if necessary, clarifying the position. Recommendations for use do not constitute a warranty, either express or implied, of the fitness or suitability of the product for a particular purpose. Main characteristics Brand Product Further characteristics Hardness Specific gravity Tensile strength Elongation at Tear resistance Compression set Food Food Drinking Drinking Flame Cure system Appeareance Typical applications Shore A [g/cm 3] [N/mm 2] break [%] [N/mm] [%] (22 h/175 °C) contact – contact – water contact water contact retardancy – ISO 48-4 ISO 1183-1A ISO 37 Typ 1 ISO 37 Typ 1 ASTM D 624 B DIN ISO 815-B BfR 1 FDA 2 – KTW 3 – WRAS UL 94 Listing Multi-purpose ELASTOSIL® LR 3003/03 3 1.01 1.3 700 3 16 Platinum (1:1 A/B) Transparent Production of molded parts, e.g. seals, valves, gaskets, membranes, O-rings ELASTOSIL® LR 3003/05 6 1.05 2.5 700 7 13 Platinum (1:1 A/B) Transparent Production of molded parts, e.g. seals, valves, gaskets, membranes, O-rings ELASTOSIL® LR 3003/10 TR 12 1.07 4.2 760 13 13 X HB (0.5 mm) Platinum (1:1 A/B) Transparent Production of molded parts, e.g. seals, valves, gaskets, membranes, O-rings ELASTOSIL® LR 3003/20 TR 22 1.09 8.3 870 24 17 X X X X HB (0.5 mm) Platinum (1:1 A/B) Transparent Production of molded parts, e.g. seals, valves, gaskets, membranes, O-rings ELASTOSIL® LR 3003/25 25 1.09 8.8 860 25 15 X X X Platinum (1:1 A/B) Transparent Production of molded parts, e.g. seals, valves, gaskets, membranes, O-rings ELASTOSIL® LR 3003/30 30 1.09 7.0 610 21 10 X X X X HB (0.5 mm) Platinum (1:1 A/B) Transparent Production of molded parts, e.g. seals, valves, gaskets, membranes, O-rings ELASTOSIL® LR 3003/40 40 1.13 10.0 610 30 11 X X X X HB (0.5 mm) Platinum (1:1 A/B) Transparent Production of molded parts, e.g. seals, valves, gaskets, membranes, O-rings ELASTOSIL® LR 3003/50 50 1.13 10.3 490 28 13 X X X X HB (0.5 mm) Platinum (1:1 A/B) Transparent Production of molded parts, e.g. seals, valves, gaskets, membranes, O-rings ELASTOSIL® LR 3003/60 60 1.13 9.5 340 27 12 X X X X HB (0.5 mm) Platinum (1:1 A/B) Transparent Production of molded parts, e.g. seals, valves, gaskets, membranes, O-rings ELASTOSIL® LR 3003/70 70 1.14 8.6 290 20 12 X X X X HB (0.5 mm) Platinum (1:1 A/B) Transparent Production of molded parts, e.g. seals, valves, gaskets, membranes, O-rings ELASTOSIL® LR 3003/80 76 1.16 8.3 240 12 13 X X X X HB (0.5 mm) Platinum (1:1 A/B) Transparent Production of molded parts, e.g. seals, valves, gaskets, membranes, O-rings ELASTOSIL® LR 3003/85 85 1.14 6.5 130 11 14 X X Platinum (1:1 A/B) Transparent Production of molded parts, e.g. seals, valves, gaskets, membranes, O-rings ELASTOSIL® LR 3003/90 90 1.13 7.0 33 8 X X X Platinum (1:1 A/B) Transparent Production of molded parts, e.g. seals, valves, gaskets, membranes, O-rings ELASTOSIL® LR 3004/30 Fast cure 30 1.10 7.5 620 24 10 X X X X HB (1.5 mm) Platinum (1:1 A/B) Transparent Economic production of molded parts, e.g. seals, O-rings, valves, gaskets, membranes ELASTOSIL® LR 3004/40 Fast cure 40 1.13 10.0 610 29 10 X X X X HB (1.5 mm) Platinum (1:1 A/B) Transparent Economic production of molded parts, e.g. seals, O-rings, valves, gaskets, membranes ELASTOSIL® LR 3004/50 Fast cure 50 1.13 10.0 480 27 12 X X X X HB (1.5 mm) Platinum (1:1 A/B) Transparent Economic production of molded parts, e.g. seals, O-rings, valves, gaskets, membranes ELASTOSIL® LR 3004/60 Fast cure 58 1.13 9.6 380 25 13 X X X X HB (1.5 mm) Platinum (1:1 A/B) Transparent Economic production of molded parts, e.g. seals, O-rings, valves, gaskets, membranes ELASTOSIL® LR 3004/70 Fast cure 70 1.14 9.5 310 23 11 X X X X HB (1.5 mm) Platinum (1:1 A/B) Transparent Economic production of molded parts, e.g. seals, O-rings, valves, gaskets, membranes ELASTOSIL® LR 3005/30 Low comp. set, npc 4, fast cure 30 1.10 6.0 610 16 13 HB (1.5 mm) Platinum (1:1 A/B) Transparent Economic production of technical molded parts, e.g. seals, O-rings, valves, gaskets, membranes ELASTOSIL® LR 3005/40 Low comp. set, npc 4, fast cure 40 1.12 7.8 600 22 16 HB (1.5 mm) Platinum (1:1 A/B) Transparent Economic production of technical molded parts, e.g. seals, O-rings, valves, gaskets, membranes ELASTOSIL® LR 3005/50 Low comp. set, npc 4, fast cure 50 1.13 9.0 500 24 15 HB (1.5 mm) Platinum (1:1 A/B) Transparent Economic production of technical molded parts, e.g. seals, O-rings, valves, gaskets, membranes ELASTOSIL® LR 3005/60 Low comp. set, npc 4, fast cure 60 1.13 9.5 380 28 18 HB (1.5 mm) Platinum (1:1 A/B) Transparent Economic production of technical molded parts, e.g. seals, O-rings, valves, gaskets, membranes ELASTOSIL® LR 3005/70 Low comp. set, npc 4, fast cure 70 1.14 8.5 330 26 19 HB (1.5 mm) Platinum (1:1 A/B) Transparent Economic production of technical molded parts, e.g. seals, O-rings, valves, gaskets, membranes High tear resistance ELASTOSIL® LR 3040/30 Fast cure, high tear 30 1.12 9.8 740 35 14 X X Platinum (1:1 A/B) Transparent Economic production (fast cure) of molded parts, e.g. baby-bottle nipples or pacifiers ELASTOSIL® LR 3040/40 Fast cure, high tear 40 1.12 9.0 600 36 11 X X Platinum (1:1 A/B) Transparent Economic production (fast cure) of molded parts, e.g. baby-bottle nipples or pacifiers ELASTOSIL® LR 3040/50 Fast cure, high tear 50 1.12 9.8 500 40 11 X X Platinum (1:1 A/B) Transparent Economic production (fast cure) of molded parts, e.g. baby-bottle nipples or pacifiers ELASTOSIL® LR 3040/60 Fast cure, high tear 60 1.14 9.7 430 40 12 X X Platinum (1:1 A/B) Transparent Economic production (fast cure) of molded parts ELASTOSIL® LR 3040/70 Fast cure, high tear 70 1.14 8.0 330 44 15 X X Platinum (1:1 A/B) Transparent Economic production (fast cure) of molded parts ELASTOSIL® LR 3043/40 High tear 40 1.14 10.0 680 36 25 X X Platinum (1:1 A/B) Transparent Production of molded parts, e.g. baby-bottle nipples or pacifiers ELASTOSIL® LR 3043/50 High tear 50 1.13 9.4 460 46 25 X X Platinum (1:1 A/B) Transparent Production of molded parts, e.g. baby-bottle nipples or pacifiers ELASTOSIL® LR 3043/60 High tear 60 1.13 9.2 390 50 20 X X Platinum (1:1 A/B) Transparent Production of molded parts ELASTOSIL® LR 3043/70 High tear 70 1.13 8.9 280 24 22 X X Platinum (1:1 A/B) Transparent Production of molded parts ELASTOSIL® LR 3015/50 Oil resistant, less abrasive, low comp. set, npc 4 50 1.34 5.4 470 12 18 Platinum (1:1 A/B) Beige Technical parts, e.g. valves, seals and O-rings in contact with oil Media resistance ELASTOSIL® LR 3015/70 Oil resistant, less abrasive, low comp. set, npc 4 70 1.33 6.1 280 15 16 Platinum (1:1 A/B) Beige Technical parts, e.g. valves, seals and O-rings in contact with oil ELASTOSIL® LR 3016/65 Oil resistant, less abrasive, low comp. set, npc 4 65 1.17 8.7 350 26 15 Platinum (1:1 A/B) White Technical parts, e.g. valves, seals and O-rings in contact with oil ELASTOSIL® LR 3020/60 Water-vapor resistant 60 1.13 6.5 280 13 10 X X X Platinum (1:1 A/B) Opaque Production of molded parts, such as gaskets, valves, membranes and o-rings ELASTOSIL® LR 3022/60 Coolant resistant 61 1.11 5.9 270 14 7 Platinum (1:1 A/B) Opaque Technical parts, e.g. valves, seals and O-rings in contact with coolant ELASTOSIL® LR 3023/60 Low comp. set, npc 4, coolant resistant 60 1.12 5.9 300 15 11 Platinum (1:1 A/B) Opaque Technical parts, e.g. valves, seals and O-rings in contact with coolant ELASTOSIL® FLR 3900/40 Fluorosilicone, fuel- and oil resistant, low comp. set, npc 4 44 1.24 6.3 400 15 20 4 Platinum (1:1 A/B) Translucent Fabrication of molded parts with fuel and oil contact ELASTOSIL® FLR 3900/60 Fluorosilicone, fuel- and oil resistant, low comp. set, npc 4 62 1.26 6.5 260 15 20 4 Platinum (1:1 A/B) Translucent Fabrication of molded parts with fuel and oil contact ELASTOSIL® FLR 3905/40 Fluorosilicone, fuel- and oil resistant, oil-bleeding, 40 1.22 4.8 300 12 16 4 Platinum (1:1 A/B) Opaque Fabrication of molded parts with fuel and oil contact low comp. set, npc 4 ELASTOSIL® FLR 3905/60 Fluorosilicone, fuel- and oil resistant, oil-bleeding, 60 1.25 5.5 240 16 16 (4 Platinum (1:1 A/B) Opaque Fabrication of molded parts with fuel and oil contact low comp. set, npc 4 Heat resistance ELASTOSIL® LR 3092/65 Low comp. set 66 1.15 10.0 330 25 10 HB (0.5 mm) Platinum (1:1 A/B) Black Post-cured technical parts in contact with high temperatures ELASTOSIL® LR 3093/65 Low comp. set 63 1.12 8.5 330 24 7 Platinum (1:1 A/B) Black Post-cured technical parts in contact with high temperatures ELASTOSIL® LR 3094/60 Low comp. set, npc 4 60 1.14 10.0 400 28 18 Platinum (1:1 A/B) Black Non-post-cured technical parts in contact with high temperatures, spark plug boots Low coefficient of friction ELASTOSIL® LR 3065/30 Low comp. set, npc 4, technical appl. 30 1.12 8.0 700 24 17 HB (0.5; 1.5; 3 mm) Platinum (1:1 A/B) Transparent Technical molded parts with low coefficient of friction, e.g. weather packs, connector seals for the automotive industry ELASTOSIL® LR 3065/50 Low comp. set, npc 4, technical appl. 50 1.12 9.0 460 31 15 HB (0.5; 1.5; 3 mm) Platinum (1:1 A/B) Transparent Technical molded parts with low coefficient of friction, e.g. weather packs, connector seals for the automotive industry ELASTOSIL® LR 3066/30 Food contact 30 1.10 7.8 660 31 12 X X Platinum (1:1 A/B) Transparent Molded parts with low coefficient of friction for food contact applications ELASTOSIL® LR 3066/40 Food contact 40 1.12 9.3 580 32 12 X X Platinum (1:1 A/B) Transparent Molded parts with low coefficient of friction for food contact applications ELASTOSIL® LR 3066/60 Food contact 60 1.13 8.9 330 27 17 X X Platinum (1:1 A/B) Transparent Molded parts with low coefficient of friction for food contact applications ELASTOSIL® LR 3066/70 Food contact 70 1.13 7.9 270 18 17 X X Platinum (1:1 A/B) Transparent Molded parts with low coefficient of friction for food contact applications ELASTOSIL® LR 3066/80 Food contact 80 1.13 6.9 180 11 13 X X Platinum (1:1 A/B) Transparent Molded parts with low coefficient of friction for food contact applications

These figures are only intended as a guide and should not be used in preparing specifications. 1 BfR recommendation XV (silicones); (BfR = Bundesinstitut für Risikobewertung). Please contact us for in-depth technical consulting to select the right product for your individual demands. A tighter specification regarding Sh-A hardness can be possible for selected products on demand (+/-1, +/-2, +/-3). 2 FDA CFR 21 § 177.2600 ”Rubber articles intended for repeated use“ (FDA = Food and Drug Administration). Please contact us if you are interested in products with specific characteristics or if you need products from our basic portfolio in other hardnesses. 3 Categories on request. 4 Non-postcured. ELASTOSIL® is a registered trademark of Wacker Chemie AG. 5 Compression set [%] (22 h/125 °C) DIN ISO 815-B. Non-postcured. CREATING TOMORROW’S SOLUTIONS

Wacker Chemie AG PRODUCT OVERVIEW Hanns-Seidel-Platz 4 81737 Munich, Germany Phone +49 89 6279-1741 www.wacker.com/contact www.wacker.com Follow us on: LIQUID SILICONE RUBBER

6709F e/05.21 replaces 6709F e/09.19 Self-adhesion · Oil-bleeding · Low viscosity · Electrically conductive · High transparency · Flame retardant · Low volatile content without post-curing

The data presented in this medium are in accordance with the present state of our knowledge but do not absolve the user from carefully checking all supplies immediately on receipt. We reserve the right to alter product constants within the scope of technical progress or new developments. The recommendations made in this medium should be checked by preliminary trials because of conditions during processing over which we have no control, especially where other companies’ raw materials are also being used. The information provided by us does not absolve the user from the obligation of investigating the possibility of infringement of third parties’ rights and, if necessary, clarifying the position. Recommendations for use do not constitute a warranty, either express or implied, of the fitness or suitability of the product for a particular purpose. Main characteristics Brand Product Further characteristics Hardness Specific gravity Tensile strength Elongation at Tear resistance Compression set Food Food Drinking Drinking Flame Cure system Appeareance Typical applications Shore A [g/cm 3] [N/mm 2] break [%] [N/mm] [%] (22 h/175 °C) contact – contact – water contact water contact retardancy – ISO 48-4 ISO 1183-1A ISO 37 Typ 1 ISO 37 Typ 1 ASTM D 624 B DIN ISO 815-B BfR 1 FDA 2 – KTW 3 – WRAS UL 94 Listing Self-adhesion ELASTOSIL® LR 3070/20 Adhesion on PA, PBT, PET, technical appl. 20 1.09 6.6 820 15 39 4 Platinum (1:1 A/B) Transparent Technical hard-soft composite parts (silicone on PA, PBT, PET), e.g. cable connectors ELASTOSIL® LR 3070/30 Adhesion on PA, PBT, PET, technical appl. 29 1.10 7.7 730 18 384 HB (0.75 mm) Platinum (1:1 A/B) Transparent Technical hard-soft composite parts (silicone on PA, PBT, PET), e.g. cable connectors ELASTOSIL® LR 3070/40 Adhesion on PA, PBT, PET, technical appl. 40 1.12 8.7 670 24 37 4 Platinum (1:1 A/B) Transparent Technical hard-soft composite parts (silicone on PA, PBT, PET), e.g. cable connectors ELASTOSIL® LR 3070/50 Adhesion on PA, PBT, PET, technical appl. 50 1.11 9.2 490 20 25 4 Platinum (1:1 A/B) Transparent Technical hard-soft composite parts (silicone on PA, PBT, PET), e.g. cable connectors ELASTOSIL® LR 3070/60 Adhesion on PA, PBT, PET, technical appl. 60 1.12 9.1 460 23 21 4 X Platinum (1:1 A/B) Transparent Technical hard-soft composite parts (silicone on PA, PBT, PET), e.g. cable connectors ELASTOSIL® LR 3071/30 Food contact 30 1.09 8.2 780 20 40 4 X X Platinum (1:1 A/B) Transparent Hard-soft composite parts (silicone on PA, PBT, PET) for food contact ELASTOSIL® LR 3071/40 Food contact 40 1.11 8.5 660 22 40 4 X X X X Platinum (1:1 A/B) Transparent Hard-soft composite parts (silicone on PA, PBT, PET) for food contact ELASTOSIL® LR 3071/50 Food contact 50 1.11 8.2 560 25 50 4 X X X X Platinum (1:1 A/B) Transparent Hard-soft composite parts (silicone on PA, PBT, PET) for food contact ELASTOSIL® LR 3071/60 Food contact 60 1.12 8.5 520 27 53 4 X X X Platinum (1:1 A/B) Transparent Hard-soft composite parts (silicone on PA, PBT, PET) for food contact ELASTOSIL® LR 3072/30 Oil-exuding 30 1.11 7.4 710 17 27 4 Platinum (1:1 A/B) Opaque Hard-soft composite parts with oil-exuding properties, e.g. connector seals or weather packs for the automotive industry ELASTOSIL® LR 3072/40 Oil-exuding 40 1.12 8.8 620 21 21 4 Platinum (1:1 A/B) Opaque Hard-soft composite parts with oil-exuding properties, e.g. connector seals or weather packs for the automotive industry ELASTOSIL® LR 3072/50 Oil-exuding 50 1.12 8.6 510 23 12 4 Platinum (1:1 A/B) Opaque Hard-soft composite parts with oil-bleeding properties, e.g. seals or weather packs for the automotive industry ELASTOSIL® LR 3074/60 Coolant resistant 60 1.13 6.8 360 14 19 4 Platinum (1:1 A/B) Opaque Hard-soft composite parts with coolant resistant properties, e.g. seals for the automotive industry ELASTOSIL® LR 3076/50 Oil resistant, less abrasive 50 1.33 5.5 470 15 184 Platinum (1:1 A/B) Beige Hard-soft composite parts with oil resistant properties, e.g. seals for the automotive industry ELASTOSIL® LR 3076/70 Oil resistant, less abrasive, low comp. set, npc 4 70 1.31 4.7 230 14 14 4 Platinum (1:1 A/B) Beige Hard-soft composite parts with oil resistant properties, e.g. seals for the automotive industry ELASTOSIL® LR 3170/40 Flame retardant 45 1.12 9.8 590 23 29 4 V-0 (3 mm); HB (0.5; 0.8 mm) Platinum (1:1 A/B) Dark gray Hard-soft composites with flame retardant properties ELASTOSIL® LR 3271/45 Flame retardant 45 1.14 7.3 540 20 454 X X X Platinum (1:1 A/B) Transparent Hard-soft composite parts with hot water resistance, e.g. for gaskets with food contact ELASTOSIL® LR 3671/30 Low coefficient of friction, food contact 30 1.12 8.9 770 29 X X Platinum (1:1 A/B) Transparent Hard-soft composite parts with low coefficient of friction, e.g. for applications with food contact ELASTOSIL® LR 3671/40 Low coefficient of friction, food contact 40 1.12 8.8 680 26 X X Platinum (1:1 A/B) Transparent Hard-soft composite parts with low coefficient of friction, e.g. for applications with food contact ELASTOSIL® LR 3675/30 Low coefficient of friction, low compression set 30 1.12 8.0 760 25 144 Platinum (1:1 A/B) Transparent Hard-soft composite parts with low coefficient of friction, e.g. for technical applications like gaskets ELASTOSIL® LR 3675/50 Low coefficient of friction, low compression set 50 1.12 7.8 410 33 124 Platinum (1:1 A/B) Transparent Hard-soft composite parts with low coefficient of friction, e.g. for technical applications like gaskets Oil-bleeding ELASTOSIL® LR 3841/50 Low comp. set, npc 4 50 1.13 9.0 490 30 13 Platinum (1:1 A/B) Opaque Oil-bleeding molded parts (around 1.5 % oil), e.g. connector seals, single wire seals ELASTOSIL® LR 3834/50 Low comp. set, npc 4 50 1.12 7.5 420 20 9 Platinum (1:1 A/B) Opaque Oil-bleeding molded parts (around 4 % oil), e.g. connector seals, single wire seals ELASTOSIL® LR 3842/40 Low comp. set, npc 4 40 1.12 8.0 610 25 15 Platinum (1:1 A/B) Opaque Oil-bleeding molded parts (around 2 % oil), e.g. connector seals, single wire seals ELASTOSIL® LR 3842/50 Low comp. set, npc 4 50 1.13 8.5 460 37 12 Platinum (1:1 A/B) Opaque Oil-bleeding molded parts (around 2 % oil), e.g. connector seals, single wire seals ELASTOSIL® LR 3842/60 Low comp. set, npc 4 60 1.14 9.2 420 38 13 Platinum (1:1 A/B) Opaque Oil-bleeding molded parts (around 2 % oil), e.g. connector seals, single wire seals ELASTOSIL® LR 3842/70 Low comp. set, npc 4 68 1.14 8.5 380 28 16 Platinum (1:1 A/B) Opaque Oil-bleeding molded parts (around 2 % oil), e.g. connector seals, single wire seals ELASTOSIL® LR 3843/30 Low comp. set, npc 4 30 1.12 8.0 680 22 19 Platinum (1:1 A/B) Opaque Oil-bleeding molded parts (around 3 % oil), e.g. mat seals, single wire seals ELASTOSIL® LR 3844/20 Low comp. set, npc 4 21 1.09 6.5 800 17 16 Platinum (1:1 A/B) Opaque Oil-bleeding molded parts (around 4 % oil), e.g. mat seals, single wire seals ELASTOSIL® LR 3844/30 Low comp. set, npc 4 30 1.10 7.2 700 22 17 Platinum (1:1 A/B) Opaque Oil-bleeding molded parts (around 4 % oil), e.g. mat seals, single wire seals ELASTOSIL® LR 3844/40 Low comp. set, npc 4 42 1.13 8.5 580 24 15 Platinum (1:1 A/B) Opaque Oil-bleeding molded parts (around 4 % oil), e.g. connector seals, single wire seals ELASTOSIL® LR 3844/50 Low comp. set, npc 4 50 1.13 8.5 500 36 14 Platinum (1:1 A/B) Opaque Oil-bleeding molded parts (around 4 % oil), e.g. connector seals, single wire seals ELASTOSIL® LR 3846/20 Low comp. set, npc 4 21 1.09 6.1 800 16 16 Platinum (1:1 A/B) Opaque Oil-bleeding molded parts (around 6 % oil), e.g. mat seals, single wire seals ELASTOSIL® LR 3846/30 Low comp. set, npc 4 30 1.11 7.0 750 19 17 Platinum (1:1 A/B) Opaque Oil-bleeding molded parts (around 6 % oil), e.g. mat seals, single wire seals ELASTOSIL® LR 3851/50 Low comp. set, npc 4, very good cut resistance 48 1.13 9.5 530 36 15 Platinum (1:1 A/B) Opaque Oil-bleeding molded parts (around 1.8 % oil), e.g. connector seals, single wire seals ELASTOSIL® LR 3852/50 Low comp. set, npc 4, excellent cut resistance 47 1.13 9.0 560 40 15 Platinum (1:1 A/B) Opaque Oil-bleeding molded parts (around 2.5 % oil), e.g. connector seals, single wire seals ELASTOSIL® LR 3856/20 Low comp. set, npc 4, excellent cut resistance 21 1.08 6.2 850 16 18 Platinum (1:1 A/B) Opaque Oil-bleeding molded parts (around 6 % oil), e. g. mat seals with excellent cut resistance, connector seals ELASTOSIL® LR 3856/30 Low comp. set, npc 4, excellent cut resistance 32 1.09 6.5 650 22 14 Platinum (1:1 A/B) Opaque Oil-bleeding molded parts (around 6 % oil), e. g. mat seals with excellent cut resistance, connector seals Low viscositiy ELASTOSIL® LR 3153 Low volume resistivity 60 1.07 7.3 160 14 Platinum (1:1 A/B) Transparent Coating of textile braided cables Electrically conductive ELASTOSIL® LR 3162 Low volume resistivity 54 1.12 5.3 340 14 Platinum (1:1 A/B) Black Electrically conductive molded parts High transparency LUMISIL® LR 7601/50 50 1.03 6.0 330 15 X X Platinum (1:1 A/B) Highly transparent Molded parts with excellent transparency LUMISIL® LR 7601/60 60 1.04 7.3 290 15 X X Platinum (1:1 A/B) Highly transparent Molded parts with excellent transparency LUMISIL® LR 7601/70 70 1.05 10.0 90 10 X X Platinum (1:1 A/B) Highly transparent Molded parts with excellent transparency LUMISIL® LR 7601/80 78 1.05 11.0 80 10 X X Platinum (1:1 A/B) Highly transparent Molded parts with excellent transparency Flame retardant ELASTOSIL® LR 3001/55 FR Low inflammability, high oil resistance 55 1.36 6.3 300 15 13 V-0 (0.75 and 3 mm) Platinum (1:1 A/B) Dark gray/black Flame retardant molded parts, e.g. anode caps ELASTOSIL® LR 3011/50 FR Low inflammability, short curing times 50 1.13 9.5 510 28 13 V-0 (0.75 and 3 mm) Platinum (1:1 A/B) Dark gray/black Lamp holder, seals in electronic equipment, low inflammability components Low volatile content ELASTOSIL® LR 5040/30 Fast cure, high tear 30 1.12 9.2 760 32 X X Platinum (1:1 A/B) Transparent Economic manufacturing without post cure of molded parts, e.g. baby bottle teats and pacifiers without post-curing ELASTOSIL® LR 5040/40 Fast cure, high tear 40 1.13 9.0 580 38 X X Platinum (1:1 A/B) Transparent Economic manufacturing without post cure of molded parts, e.g. baby bottle teats and pacifiers ELASTOSIL® LR 5040/45 Fast cure, high tear 45 1.12 9.0 580 38 X X Platinum (1:1 A/B) Transparent Economic manufacturing without post cure of molded parts, e.g. baby bottle teats and pacifiers ELASTOSIL® LR 5040/50 Fast cure, high tear 50 1.13 9.5 490 42 X X Platinum (1:1 A/B) Transparent Economic manufacturing without post cure of molded parts, e.g. baby bottle teats and pacifiers ELASTOSIL® LR 5040/60 Fast cure, high tear 60 1.13 9.0 380 50 X X Platinum (1:1 A/B) Transparent Economic manufacturing without post cure of molded parts, e.g. baby bottle teats and pacifiers ELASTOSIL® LR 5040/70 Fast cure, high tear 70 1.13 9.5 370 36 X X Platinum (1:1 A/B) Transparent Economic manufacturing without post cure of molded parts, e.g. baby bottle teats and pacifiers

These figures are only intended as a guide and should not be used in preparing specifications. 1 BfR recommendation XV (silicones); (BfR = Bundesinstitut für Risikobewertung). Please contact us for in-depth technical consulting to select the right product for your individual demands. A tighter specification regarding Sh-A hardness can be possible for selected products on demand (+/-1, +/-2, +/-3). 2 FDA CFR 21 § 177.2600 ”Rubber articles intended for repeated use“ (FDA = Food and Drug Administration). Please contact us if you are interested in products with specific characteristics or if you need products from our basic portfolio in other hardnesses. 3 Categories on request. 4 Non-postcured. ELASTOSIL® and LUMISIL® are registered trademarks of Wacker Chemie AG. 5 Compression set [%] (22h/125 °C) DIN ISO 815-B. Non-postcured. CREATING TOMORROW’S SOLUTIONS

Wacker Chemie AG PRODUCT OVERVIEW 09.19

Hanns-Seidel-Platz 4 / 81737 Munich, Germany Phone +49 89 6279-1741 www.wacker.com/contact www.wacker.com Follow us on: ADDITION CURING 05.21 replaces 6709G e /

6709G e SOLID SILICONE RUBBER

Multi-purpose · High tear resistance · Low compression set · High elasticity · Low coefficient of friction · Self-adhesion · High heat resistance · Oil bleeding · Electrically conductive

The data presented in this medium are in accordance with the present state of our knowledge but do not absolve the user from carefully checking all supplies immediately on receipt. We reserve the right to alter product constants within the scope of technical progress or new developments. The recommendations made in this medium should be checked by preliminary trials because of conditions during processing over which we have no control, especially where other companies’ raw materials are also being used. The information provided by us does not absolve the user from the obligation of investigating the possibility of infringement of third parties’ rights and, if necessary, clarifying the position. Recommendations for use do not constitute a warranty, either express or implied, of the fitness or suitability of the product for a particular purpose. Main characteristics Brand Product Hardness Specific gravity Tensile strength Elongation at break Tear resistance Compression set Food contact - Food contact - Molding Extrusion Cure system Appearance Typical applications Shore A [g/cm 3] [N/mm 2] [%] [N/mm] [%] (22 h/175 °C) BfR 1 FDA 2 ISO 48-4 ISO 1183-1A ISO 37 Typ 1 ISO 37 Typ 1 ASTM D 624 B DIN ISO 815-B Multi-purpose ELASTOSIL® R plus 4001/20 20 1.10 8.0 1300 34 30 X X X Platinum (1 component, ready to use) Transparent Molded parts, e.g. seals, membranes, baking molds ELASTOSIL® R plus 4001/30 30 1.10 11.5 1030 45 37 X X X Platinum (1 component, ready to use) Transparent Molded parts, e.g. seals, membranes, baking molds ELASTOSIL® R plus 4001/40 40 1.11 10.9 1000 38 22 X X X Platinum (1 component, ready to use) Transparent Molded parts, e.g. seals, membranes, baking molds ELASTOSIL® R plus 4001/50 50 1.13 11.5 870 39 20 X X X Platinum (1 component, ready to use) Transparent Molded parts, e.g. seals, membranes, baking molds ELASTOSIL® R plus 4001/60 60 1.14 11.0 740 30 20 X X X Platinum (1 component, ready to use) Transparent Molded parts, e.g. seals, membranes, baking molds or spark plug boots ELASTOSIL® R plus 4001/70 70 1.17 10.3 740 38 30 X X X Platinum (1 component, ready to use) Transparent Molded parts, e.g. seals, membranes, baking molds or spark plug boots ELASTOSIL® R plus 4001/80 80 1.20 8.0 640 29 45 X X X Platinum (1 component, ready to use) Transparent Molded parts, e.g. seals, membranes, baking molds ELASTOSIL® R plus 4001/90 88 1.21 6.5 245 18 27 X X X Platinum (1 component, ready to use) Transparent Molded parts, e.g. seals, membranes, baking molds ELASTOSIL® R plus 4110/60 60 1.15 10.5 790 40 11 X X X Platinum (1 component, ready to use) Transparent Extruded parts, e.g. tubes or profiles High tear resistance ELASTOSIL® R plus 4000/40 40 1.12 9.3 860 46 35 X X X Platinum (100:1.5 base + catalyst) Transparent Molded parts, e.g. baby-bottle nipples or pacifiers ELASTOSIL® R plus 4000/50 50 1.13 9.1 850 49 43 X X X Platinum (100:1.5 base + catalyst) Transparent Molded parts, e.g. baby-bottle nipples or pacifiers ELASTOSIL® R plus 4000/60 60 1.16 9.9 680 50 23 X X X Platinum (100:1.5 base + catalyst) Transparent Molded parts, e.g. baby-bottle nipples or pacifiers ELASTOSIL® R plus 4000/70 70 1.16 9.3 590 54 19 X X X Platinum (100:1.5 base + catalyst) Transparent Molded parts, e.g. baby-bottle nipples or pacifiers ELASTOSIL® R plus 4020/40 39 1.14 10.9 1000 46 29 X X X Platinum (1 component, ready to use) Transparent Molded parts under high mechanical stress, e.g. baby-bottle nipples or pacifiers ELASTOSIL® R plus 4020/50 49 1.16 11.0 830 45 26 X X X Platinum (1 component, ready to use) Transparent Molded parts under high mechanical stress, e.g. baby-bottle nipples or pacifiers ELASTOSIL® R plus 4020/60 59 1.18 11.9 850 48 18 X X X Platinum (1 component, ready to use) Transparent Molded parts under high mechanical stress, e.g. baby-bottle nipples or pacifiers ELASTOSIL® R plus 4020/70 71 1.20 10.4 660 51 22 X X X Platinum (1 component, ready to use) Transparent Molded parts under high mechanical stress, e.g. baby-bottle nipples or pacifiers ELASTOSIL® R plus 4305/30 30 1.11 11.8 1100 43 8 X X X Platinum (100:1.5 base + catalyst) Transparent Extruded parts, e.g. tubes or profiles ELASTOSIL® R plus 4305/40 40 1.12 9.8 830 27 7 X X X Platinum (100:1.5 base + catalyst) Transparent Extruded parts, e.g. tubes or profiles ELASTOSIL® R plus 4305/50 50 1.14 8.8 770 35 7 X X X Platinum (100:1.5 base + catalyst) Transparent Extruded parts, e.g. tubes or profiles ELASTOSIL® R plus 4305/60 S 57 1.17 9.9 630 38 13 X X X Platinum (100:1.5 base + catalyst) Transparent Extruded parts, e.g. tubes or profiles ELASTOSIL® R plus 4305/70 70 1.18 9.1 600 39 14 X X X Platinum (100:1.5 base + catalyst) Transparent Extruded parts, e.g. tubes or profiles ELASTOSIL® R plus 4305/80 80 1.19 7.8 310 21 17 X X X Platinum (100:1.5 base + catalyst) Transparent Extruded parts, e.g. tubes or profiles ELASTOSIL® R plus 4305/90 90 1.20 6.4 150 17 30 X X X Platinum (100:1.5 base + catalyst) Transparent Extruded parts, e.g. tubes or profiles Low compression set ELASTOSIL® R plus 4060/50 50 1.15 8.0 500 25 9 X X X Platinum (1 component, ready to use) Transparent Molded parts, e.g. gaskets ELASTOSIL® R plus 4060/60 60 1.15 7.5 380 20 10 X X X Platinum (1 component, ready to use) Transparent Molded parts, e.g. gaskets High elasticity ELASTOSIL® R plus 4360/60 60 1.15 8.4 380 18 10 X X X Platinum (100:1.5 base + catalyst) Transparent Extruded parts, e.g. profiles with low compression set Low coefficient of friction ELASTOSIL® R plus 4066/60 60 1.15 8.0 660 40 27 X X X Platinum (1 component, ready to use) Transparent Molded parts with low coefficient of friction, e.g. seals ELASTOSIL® R plus 4366/60 60 1.15 7.6 550 41 20 X X X Platinum (100:1.5 base + catalyst) Transparent Extruded parts, e.g. profiles with low coefficient of friction, special tubes or flat seals Self-adhesion ELASTOSIL® R plus 4070/20 22 1.07 7.9 1300 35 57 X Platinum (1 component, ready to use) Translucent Hard-soft composite molded parts, primerless adhesion to various plastic substrates (e.g. PA. PBT) and metals ELASTOSIL® R plus 4070/30 31 1.11 10.5 1200 52 463 X Platinum (1 component, ready to use) Translucent Hard-soft composite molded parts, primerless adhesion to various plastic substrates (e.g. PA. PBT) and metals ELASTOSIL® R plus 4070/60 62 1.17 10.0 790 39 49 3 X Platinum (1 component, ready to use) Translucent Hard-soft composite molded parts, primerless adhesion to various plastic substrates (e.g. PA. PBT) and metals ELASTOSIL® R plus 4370/40 40 1.14 10.9 1000 39 43 3 X Platinum (100:1.5 base + catalyst) Translucent Extruded or coextruded parts ELASTOSIL® R plus 4370/50 48 1.14 10.6 900 42 43 3 X Platinum (100:1.5 base + catalyst) Translucent Extruded or coextruded parts High heat resistance ELASTOSIL® R plus 4050/55 55 1.13 8.4 400 23 X X X Platinum (1 component. ready to use) Black Molded parts, e.g. gaskets for high temperature applications ELASTOSIL® R plus 4350/55 58 1.13 8.2 350 18 10 X X X Platinum (100:1.5 base + catalyst) Transparent Extruded parts, e.g. profiles for high temperature applications Oil bleeding ELASTOSIL® R plus 4806/20 20 1.05 6.0 950 17 17 X Platinum (1 component, ready to use) Opaque Oil-exuding molded parts, e.g. mat seals, weather packs for the automotive industry ELASTOSIL® R plus 4846/30 30 1.11 10.0 1000 32 19 X Platinum (1 component, ready to use) Opaque Oil-exuding molded parts, e.g. mat seals, weather packs for the automotive industry Electrically conductive ELASTOSIL® R plus 573/50 50 1.11 5.5 370 16 32 X Platinum (A/B component) Black Production of electrically conductive cable components and profiles (volume resistivity 7.4 Ω cm) ELASTOSIL® R plus 573/70 71 1.16 6.5 246 17 36 X Platinum (A/B component) Black Production of electrically conductive cable components and profiles (volume resistivity 1.8 Ω cm)

These figures are only intended as a guide and should not be used in preparing specifications.

1 BfR recommendation XV (silicones); (BfR = Bundesinstitut für Risikobewertung). 2 FDA CFR 21 § 177.2600 ”Rubber articles intended for repeated use“ (FDA = Food and Drug Administration). 3 Not post-cured, other values in this column after 4h/200 °C post-curing. Please contact us for in-depth technical consulting to select the right product for your individual demands. Please contact us if you are interested in products with specific characteristics or if you need products from our basic portfolio in other hardnesses.

ELASTOSIL® is a registered trademark of Wacker Chemie AG. Valves Interfaces for infant nasal breathing tubes CREATING TOMORROW’S SOLUTIONS

Breathing tube Ventilation mask

Handles for surgical instruments Ventilation bag

Seals Catheter

Wacker Chemie AG PRODUCT OVERVIEW 09.19

Hanns-Seidel-Platz 4 / 81737 Munich, Germany Phone +49 89 6279-1741 www.wacker.com/contact

www.wacker.com Follow us on: SILICONE RUBBER FOR 05.21 replaces 6709H e

Valve Syringe seals /

6709H e MEDICAL APPLICATIONS

Liquid Silicone Rubber · Multi-purpose · High tear resistance · Low coefficient of friction · Non-healing · Self-adhesion Solid Silicone Rubber · Multi-purpose · High tear resistance ·

The data presented in this medium are in accordance with the present state of our knowledge but do not absolve the user from carefully checking all supplies immediately on Low coefficient of friction receipt. We reserve the right to alter product constants within the scope of technical progress or new developments. The recommendations made in this medium should be checked by preliminary trials because of conditions during processing over which we have no control, especially where other companies’ raw materials are also being used. The information provided by us does not absolve the user from the obligation of investigating the possibility of infringement of third parties’ rights and, if necessary, clarifying the position. Recommendations for use do not constitute a warranty, either express or implied, of the fitness or suitability of the product for a particular purpose. Main characteristics Brand Product Product type / cure system Hardness Specific gravity Tensile strength Elongation at Tear resistance Compression set Food contact – Food contact – Medical. pharma. Medical pharma.. Molding Extrusion Appearance Typical applications Shore A [g/cm 3] [N/mm 2] break [%] [N/mm] [%] (22 h/175 °C) BfR 1 FDA 2 biotech – USP biotech – ISO 48-4 ISO 1183-1A ISO 37 Typ 1 ISO 37 Typ 1 ASTM D 624 B DIN ISO 815-B Class VI 3 ISO 10993 4 Liquid silicone rubber Multi purpose SILPURAN® 6000/05 LSR, platinum (1:1 A/B) 5 1.04 2.5 700 6 15 X X X Transparent Molded parts for the medical and pharma industry SILPURAN® 6000/10 LSR, platinum (1:1 A/B) 10 1.07 4.2 740 12 15 X X X Transparent Molded parts for the medical and pharma industry SILPURAN® 6000/20 LSR, platinum (1:1 A/B) 20 1.08 8.0 850 21 17 X X X X X Transparent Molded parts for the medical and pharma industry SILPURAN® 6000/30 LSR, platinum (1:1 A/B) 30 1.10 8.6 650 25 13 X X X X X Transparent Molded parts for the medical and pharma industry SILPURAN® 6000/40 LSR, platinum (1:1 A/B) 40 1.12 9.6 600 29 13 X X X X X Transparent Molded parts for the medical and pharma industry SILPURAN® 6000/50 LSR, platinum (1:1 A/B) 50 1.13 10.0 480 30 14 X X X X X Transparent Molded parts for the medical and pharma industry SILPURAN® 6000/60 LSR, platinum (1:1 A/B) 60 1.13 10.0 350 27 14 X X X X X Transparent Molded parts for the medical and pharma industry SILPURAN® 6000/70 LSR, platinum (1:1 A/B) 70 1.15 9.5 290 22 11 X X X X X Transparent Molded parts for the medical and pharma industry High tear resistance SILPURAN® 6400/40 LSR, platinum (1:1 A/B) 40 1.12 9.2 630 35 25 X X X X X Transparent Molded parts for the medical and pharma industry SILPURAN® 6400/50 LSR, platinum (1:1 A/B) 50 1.12 9.1 450 47 25 X X X X X Transparent Molded parts for the medical and pharma industry SILPURAN® 6400/60 LSR, platinum (1:1 A/B) 60 1.13 9.5 430 51 20 X X X X X Transparent Molded parts for the medical and pharma industry Low coefficient of friction SILPURAN® 6600/40 LSR, platinum (1:1 A/B) 40 1.12 9.4 550 32 14 X X X X X Transparent Molded parts for the medical and pharma industry with a low coefficient of friction SILPURAN® 6600/50 LSR, platinum (1:1 A/B) 50 1.12 8.9 440 31 13 X X X X X Transparent Molded parts for the medical and pharma industry with a low coefficient of friction SILPURAN® 6600/60 LSR, platinum (1:1 A/B) 60 1.12 9.0 310 26 14 X X X X X Transparent Molded parts for the medical and pharma industry with a low coefficient of friction Non-healing SILPURAN® 6610/40 LSR, platinum (1:1 A/B) 40 1.21 7.2 510 20 12 X X X X X White Needle free valves, slit membranes where healing needs to be avoided SILPURAN® 6610/50 LSR, platinum (1:1 A/B) 50 1.23 8.0 450 25 9 X X X X X White Needle free valves, slit membranes where healing needs to be avoided SILPURAN® 6610/60 LSR, platinum (1:1 A/B) 60 1.23 7.0 300 20 15 X X X X X White Needle free valves, slit membranes where healing needs to be avoided Self adhesion SILPURAN® 6700/40 LSR, platinum (1:1 A/B) 40 1.11 8.5 640 23 X X X X X Transparent Hard-soft composite parts for the medical and pharma industry (silicone on PA. PBT) SILPURAN® 6700/50 LSR, platinum (1:1 A/B) 50 1.12 8.5 590 24 X X X X X Transparent Hard-soft composite parts for the medical and pharma industry (silicone on PA. PBT) SILPURAN® 6700/60 LSR, platinum (1:1 A/B) 60 1.12 8.2 490 26 X X X X X Transparent Hard-soft composite parts for the medical and pharma industry (silicone on PA. PBT) Self adhesion. high tear SILPURAN® 6740/40 LSR, platinum (1:1 A/B) 40 1.10 9.2 710 25 10 X X X X X Transparent Hard-soft composite parts for the medical and pharma industry (silicone on PA. PBT) Self adhesion, low coefficient of friction SILPURAN® 6760/50 LSR, platinum (1:1 A/B) 50 1.10 8.4 600 27 X X X X X Transparent Hard-soft composite parts for the medical and pharma industry (silicone on PA. PBT) X-ray opaque ELASTOSIL® LR 34004/50 LSR, platinum (1:1 A/B) 50 1.23 7.8 450 26 X X X X X White X-ray opaque injection molding parts Solid silicone rubber Multi purpose SILPURAN® 8020/40 HTV, platinum (100:1.5 base + catalyst) 40 1.12 11.1 820 34 25 X X X X X Translucent Molded parts for the medical and pharma industry SILPURAN® 8020/50 HTV, platinum (100:1.5 base + catalyst) 50 1.14 11.2 760 35 30 X X X X X Translucent Molded parts for the medical and pharma industry SILPURAN® 8020/60 HTV, platinum (100:1.5 base + catalyst) 60 1.16 11.2 670 31 30 X X X X X Translucent Molded parts for the medical and pharma industry SILPURAN® 8020/70 HTV, platinum (100:1.5 base + catalyst) 70 1.18 10.4 650 37 35 X X X X X Translucent Molded parts for the medical and pharma industry SILPURAN® 8030/40 HTV, platinum (100:1.5 base + catalyst) 40 1.13 9.7 810 30 14 X X X X X Translucent Extruded parts, e.g. tubes and profiles for the medical and pharma industry SILPURAN® 8030/50 HTV, platinum (100:1.5 base + catalyst) 50 1.14 10.5 850 35 20 X X X X X Translucent Extruded parts, e.g. tubes and profiles for the medical and pharma industry SILPURAN® 8030/60 HTV, platinum (100:1.5 base + catalyst) 60 1.17 10.7 710 39 25 X X X X X Translucent Extruded parts, e.g. tubes and profiles for the medical and pharma industry SILPURAN® 8030/70 HTV, platinum (100:1.5 base + catalyst) 70 1.18 9.7 650 41 25 X X X X X Translucent Extruded parts, e.g. tubes and profiles for the medical and pharma industry SILPURAN® 8060/40 HTV, peroxide (base + Crosslinker E) 42 1.12 9.3 560 23 35 X X X X X Transparent Medical / pharmaceutical extruded or molded parts SILPURAN® 8060/50 HTV, peroxide (base + Crosslinker E) 50 1.14 11.0 520 25 35 X X X X X Transparent Medical / pharmaceutical extruded or molded parts SILPURAN® 8060/60 HTV, peroxide (base + Crosslinker E) 60 1.15 11.0 470 25 25 X X X X X Transparent Medical / pharmaceutical extruded or molded parts SILPURAN® 8060/70 HTV, peroxide (base + Crosslinker E) 70 1.18 11.6 480 29 35 X X X X X Transparent Medical / pharmaceutical extruded or molded parts High tear resistance SILPURAN® 8461/60 HTV, peroxide (base + Crosslinker E) 61 1.18 10.5 480 33 31 X X X X X Transparent Medical / pharmaceutical extruded parts with high tear resistance, e.g. tubes or profiles Low coefficient of friction SILPURAN® 8630/60 HTV, platinum (100:1.5 base + catalyst) 60 1.15 8.0 510 41 17 X X X X X Translucent Extruded parts with low coefficient of friction, e.g. tubes and profiles for the medical and pharma industry Barium sulfate batch SILPURAN® AUX 8250 RO Barium sulfate batch (75 %) X X X X White X-ray opaque additive for peroxide-curing silicone rubber compounds SILPURAN® AUX 8251 RO Barium sulfate batch (75 %) X X X X White X-ray opaque additive for platinum-curing silicone rubber compounds

All SILPURAN® products are produced in accordance to WACKER CLEAN OPERATIONS standards. These figures are only intended as a guide and should not be used in preparing specifications.

1 BfR recommendation XV (silicones); (BfR = Bundesinstitut für Risikobewertung). 2 FDA CFR 21 § 177.2600 ”Rubber articles intended for repeated use“ (FDA = Food and Drug Administration). 3 Systemic / intracut. toxicity, implantation test (additional tests on request). 4 Cytotoxicity, sensitization as per LLNA, pyrogenicity (additional tests on request). Please contact us about the compliance of our SILPURAN® grades with European Pharmacopoeia, Chapter 3.1.9 ”Silicone elastomers for closures and tubing“. Please contact us for in-depth technical advice on selecting the right product for your individual needs. Please contact us if you are interested in products with specific characteristics or if you need products from our basic portfolio in other hardnesses. Device Master Files listed at FDA.

SILPURAN® and ELASTOSIL® are registered trademarks of Wacker Chemie AG.

Impregnated?????????? outdoor jacket Architectural textile CREATING TOMORROW’S SOLUTIONS

Silicone-coated nonvoven fabric Silicone-printed fabric

Fire-protective Silicone-coated airbag clothing

Wacker Chemie AG PRODUCT OVERVIEW 09.19

Hanns-Seidel-Platz 4 / 81737 Munich, Germany Phone +49 89 6279-1741 www.wacker.com/contact Silicone-coated hose for thermal insulation Silicone-coated non-slip garter www.wacker.com Follow us on: SILICONE RUBBER 6934e replaces 05.21 /

6934e FOR TEXTILE COATING

Rubber Dispersions · High Temperature Curing Silicone Rubber · Room Temperature Curing Silicone Rubber · Top Coats

* Valid for the silicone base. Additives have to be evaluated separately! ** Valid after post-curing (4h/200 °C)

ELASTOSIL® is a registered trademark of Wacker Chemie AG. CREATING TOMORROW’S SOLUTIONS

Wacker Chemie AG 09.19

Hanns-Seidel-Platz 4 / 81737 Munich, Germany SOLID AND LIQUID SILICONE RUBBER Phone +49 89 6279-1741 www.wacker.com/contact MATERIAL AND PROCESSING www.wacker.com Follow us on:

6709e replaces 05.21 / GUIDELINES 6709e