In-Mold Labeling (IML) for HP Indigo Labels and Packaging Digital Presses
How-to Guide
November 2015 © 2015 Copyright HP Development Company, L.P.
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Part Number: CA494-18500
Edition: November 2015 Table of contents
1 Overview ...... 1 Who can benefit from reading this document? ...... 1
2 Introduction to in-mold labeling (IML) ...... 2 What is in-mold labeling (IML)? ...... 2 Market and applications ...... 3 Fast-moving consumer goods (FMCG) ...... 5 Durable goods ...... 5
3 Production process ...... 6 General ...... 6 Design and Pre-press ...... 6 Substrates ...... 8 Priming ...... 10 Printing ...... 13 Finishing (varnish) ...... 14 Converting (die-cutting and stacking) ...... 17 Molding ...... 19 Injection Molding ...... 20 Blow Molding ...... 21 Thermoforming ...... 22 Examples of E2E (end-to-end) process ...... 23 Injection molding ...... 23 Blow molding ...... 24
4 Quality assurance and best practice ...... 25 Issues affecting IML end product quality and production process ...... 25 Standard quality tests for labels and end product ...... 27 Regulatory aspects ...... 29
Appendix A Obtaining customer support ...... 30 Materials Application Team (MAT) ...... 30 My HP Indigo ...... 30 RIT’s HP Indigo Over-Print Varnish (OPV) performance program ...... 30 Suppliers and vendors list ...... 31
ENWW CA494-18500 iii Appendix B Related documentation ...... 33
Appendix C Glossary ...... 34 Terms and acronyms ...... 34
Appendix D Recycling codes ...... 37 Recycling codes ...... 37
Appendix E Service and support ...... 39 Printing instructions ...... 40
iv ENWW 1Overview
Who can benefit from reading this document? This document is intended for: ● Owners and operators of HP Indigo Labels and Packaging Digital Presses, with special focus on HP Indigo 20000 Digital Press and HP Indigo WS6000 Series Digital Presses. ● Converters and manufacturers of in-mold labeling products. ● HP Indigo customer support, marketing and sales organizations. This document provides information about the in-mold labeling (IML) process with a special focus on digital printing technology by HP Indigo. ● If you are currently producing in-mold labels using conventional methods (offset, flexo, gravure), this document will inform you about the short-to-medium run, high quality alternative that HP Indigo digital printing is introducing to the IML market. ● If you already own an HP Indigo press and you use it for printing other labels (pressure-sensitive labels, wine labels), you may be interested in learning more about the IML opportunity. ● If you already use your HP Indigo press for printing in-mold labels, this “cookbook” will expand your knowledge and guide you through our recommended materials and processes, throughout IML production. This document will also help you understand and overcome the technical challenges which arise during the very demanding production stages of in-mold labeling.
ENWW Who can benefit from reading this document? 1 2 Introduction to in-mold labeling (IML)
What is in-mold labeling (IML)? In-mold labeling (IML) is the simultaneous, one-shot molding of a plastic container/part together with an attached label. The label is fused with the plastic container/part to achieve a “no-label” look. In-mold labels can be found on cans, cups and lids available on all supermarket shelves, where they attract consumers to food and non-food products. Why choose in-mold labels (IML) over pressure-sensitive labels (PSL)? The in-mold labels are part of the label-family, next to shrink sleeves, wraparound labels and pressure- sensitive labels. The in-mold labels advantages over other labels are that they do not require additional glue during application and have great resistance to moisture, chemicals and scratching. To achieve this high performance, IML production usually requires materials (substrate, ink, protective varnish) that can withstand high temperatures during the molding process. The main difference between an in-mold label and a pressure-sensitive label is that the pressure-sensitive label is affixed to the surface of the plastic container, while the in-mold label actually becomes part of the finished product. There are three types of in-mold labeling: ● Injection Molding — Typically used for small containers (up to 1 kg) with lids, in the food and perishables industry, for products such as ice cream, cheese, butter and sour cream. ● Blow Molding — Typically used for bottles and large containers (up to 5 kg), for health and beauty products (e.g. shampoo, lotions), and other products such as motor oils and housecleaning products. ● Thermoforming — Typically used for small containers (like with injection molding), for products in the food and perishables industry. Figure 2-1 Examples of in-mold labeling types
1 Blow molding labeling 2 Injection molding labeling 3 Thermoforming labeling
Each type of in–mold labeling and the corresponding process parameters will be discussed more in details in the “Production process” chapter (see Molding on page 19).
2 Chapter 2 Introduction to in-mold labeling (IML) ENWW Market and applications The label market is characterized by a variety of target markets and applications. In-mold labeling (IML) is one of the smallest sub-markets, with roughly 2% share of global labels volume. Figure 2-2 Global market share by labeling technology
While there are many advantages to in-mold labeling, such as aesthetics and high durability, there are two main barriers to the overall market growth: the typical IML supply chain is long and complicated, and many of the materials used (such as substrates, varnishes, etc.) are more costly in comparison to pressure-sensitive (PS) labels or sleeve applications. Nevertheless, in-mold labeling is a dynamic industry showing stable growth rate in recent years, with a promising 5% annual growth in some areas. Currently, Europe is the dominant global leader of the IML market, with 54% market share in 2014. Next are North America with 25% share, APJ with 13%, Africa and ME with 4% and Latin America (mostly Brazil) with 4%.
ENWW Market and applications 3 Figure 2-3 Global market share for IML by region
There are three main technologies for molding: injection mold, blow mold and thermoforming. Injection molding is the most common one with roughly 68% share, blow molding comes second with 31% share, and thermoforming is the least common of all. Figure 2-4 Global market share by molding technology
IML is used for two main end-use markets: the fast moving consumer goods (FMCG) market and the durable goods market. The molding method is not set based on the end-use segment, and both injection and blow molding are used for durable containers as well as for FMCG.
4 Chapter 2 Introduction to in-mold labeling (IML) ENWW Fast-moving consumer goods (FMCG) The fast-moving consumer goods is a very critical market when it comes to legislation and regulation for food and (to some extent) pharmaceuticals; it is however less demanding in regards to the product’s ability to serve for a long time, as many of the packages will only be used once (i.e., the containers will be thrown away once empty). IML serves in two main product categories within the FMCG world: ● Food — Mainly tubes (butter, ice cream, etc.) and bucket-like containers (e.g. dried soup powder). ● Home and personal care — IML is mostly used in the home detergent segment (laundry, general cleaning), and for some personal care products (such as shampoos). In both product categories, the labels are usually printed on the outside (surface printing) and protected with an overprint varnish. The containers are typically made from polyolefins (PP and PE), as well as the labels (mainly PP). Figure 2-5 Examples of in-mold labeling for fast-moving consumer goods
Durable goods The durable goods market is a very demanding market because products are used for 1–10 years. They need to be resistant to the dishwasher, to weather and scratching, etc. Labels are typically protected with a thick layer of UV varnish, or are reverse printed and laminated with a second layer to ensure ink protection. In this market, besides PP more types of plastic (ABS, PC, PS) are used because their specific properties are more fitting for the applications. Examples of durable goods using in-mold labels are: suitcases, lunch boxes, beer crates, toys and sporting goods. In these cases the in-mold labels are often called In-Mold Decoration (IMD). Figure 2-6 Examples of in-mold labeling for durable goods
ENWW Market and applications 5 3 Production process
General The IML manufacturing process is usually performed by several parties, starting with the printing converter. Here the labels are printed on special substrate, the ink is protected by either varnish or over-lamination, and the printed labels are die-cut and stacked (⇒ “cut and stack” labels). These pre-cut labels are then transferred to the container manufacturer for the molding process. After the container/part is molded with the label, it is shipped to the brand for the filling process. There are also many printing converters who install molding machinery at their facility to speed up the lead time, and provide “end-to-end” (E2E) service to the brands by controlling all stages of the IML production process. The IML production flow is shown below. The steps are described in the next sections. Figure 3-1 IML process flow
The figure below illustrates the basic structure of an in-mold label. Figure 3-2 Basic structure of in-mold label
Design and Pre-press Usually the end product will dictate both the molding technology and the label design. If there is some freedom in label design/shape, the molding equipment and the automation readiness can provide additional focus into something specific. In-mold labels can be of many different sizes and shapes. Compared to self-adhesive labels (SALs), the IMLs are usually equal or larger in size. In general, we can divide the labels into four major groups/shapes:
6 Chapter 3 Production process ENWW Lid label Side + back label Straight label Conic label
Since printed materials are usually bi-oriented, and orientation (and also shrink) is mostly in the machine (length) direction (MD), labels are usually positioned following the length direction. Depending on the finishing equipment, labels can be combined (nesting) to save material (as shown in the figure below). Depending on the design, if the unprinted area between the labels is large, then it is highly recommended to cover it with an ink background layer (for example 50-100% Yellow) to avoid a difference in thickness of the printed film which could cause damage to it. In this application it is extremely important that the film lay flat, without curling. Figure 3-3 Label image positioning and background layer design
1 Background ink layer 2 Labels
Gate area When designing the label image it is important to consider the gate area. In injection molding, the gate area is where the high-pressure and high-temperature molten plastic enters the mold and meets the label; this is often the case with a lid IML application, or when a label covers the bottom of a container. The gate area (usually round shaped, with a diameter of up to 10mm), might cause defects to the printed inks due to its higher temperature and pressure compared to the rest of the mold. HP ElectroInk is a thin (up to ~5 microns) thermoplastic layer that softens at temperatures above 100 °C. As a consequence, if you are not working with optimum materials and parameters, some ink flowing and color change (= ink washout) can be seen in the gate area. To avoid or minimize defects occurring at the gate area, follow these tips:
ENWW Design and Pre-press 7 ● Reduce the temperature and increase the dwell time of the injection. This has been proven the most effective way, providing the highest improvement. ● Lower ink coverage. When designing an image above the gate area, it is highly recommended to lower the ink coverage down to not more than 200%. This provides higher thermal/pressure durability. ● Use solid printed areas above the gate, and not fine lines and text. If any ink flow happens, it will be less visible on the solid areas. ● For “label above gate area” applications, use suitable materials (primer and varnish) with higher thermal resistance. Substrates Substrates are selected according to the requirements of the application, the machine/process used, the desired finish/appearance, and the cost. These parameters are usually dictated by the molder to the printer/ converter. The molder provides the end-product (container with fused label) to the brand, per its specification. The label material is usually of the same or similar chemistry as the container material, because of the following aspects: ● Chemical compatibility — When heat-fusing two plastics, to achieve a good bond the materials must be chemically similar. For example, most containers for consumer goods IML applications are polyolefins such as PP or PE. Therefore most of the label materials for this market are of PP type (PE is less suitable for IML applications due to its low mechanical properties). ● Recycling — Having the container and the label made of the same material makes their recycling much easier and productive, since no separation processes are needed. The IML package is fully recyclable. (For additional info on recycling and its codes refer to Recycling codes on page 37).
Main container substrate types:
● PP (Polypropylene) — The most used type in the IML industry. Mainly used for FMCG (fast-moving consumer goods), which are the focus of this How-to Guide, and the best fit HP Indigo technology. In recent years PP is also being successfully tested and used in more durable applications. ● PE (Polyethylene) — Used mainly in blow molding market for bottles. ● PS (Polystyrene) — Used in fast food and sweets markets, such as noodle cups and chocolate boxes. ● ABS (Acrylonitrile butadiene styrene) — Used for long-life products such as lunch boxes. ● PC (Polycarbonate) — Used for transparent products, such as beer glasses and automotive parts. ● PET (Polyester) — Used for high temperature and high barrier applications. Sometimes a blend of resin types is used to achieve multiple characteristics for the desired part, like the ABS- PC blend used in the automotive industry for dashboard decorations.
Main IML film substrate types:
● Cavitated BOPP (biaxially-oriented polypropylene) ● Solid-core BOPP (biaxially-oriented polypropylene) ● CPP (cast polypropylene) Although there are some PET/PE/PS films used in this market, the very vast majority of IML films for FMCG are PP films (and this is our focus in this How-to Guide).
8 Chapter 3 Production process ENWW Main film properties vs. application: ● Thickness — Most of the IML film grades are from 40 to 120 microns. For injection and thermoforming the thickness is usually on the lower end, up to 90 microns, while most of the applications are about 40-70 microns. For blow molding, the thickness is usually higher – about 80-120 microns. Since IMLs are not supported with any liner (unlike the self-adhesive labels), they need to demonstrate some mechanical strength and stability during the die-cutting and molding process. The thicker the label, the more stable it will be during the production. This is the reason that for larger size labels it is recommended to choose thicker materials. ● Density — With the introduction of voided/cavitated film extrusion technique (which means the film contains tiny air bubbles), film manufacturers learned how to produce thicker and mechanical stable films while using less material. The density of these cavitated BOPPs ranges between 0.55 and 0.80 gr/ cm3. There are some micro-cavitated materials which can get as high as 0.80-0.88 gr/cm3 in density. Solid-core BOPPs and CPPs have the highest density of 0.88-0.96 gr/cm3. When looking at the IML market, we can clearly see that the majority of the BOPP films are indeed cavitated. ● Visual and texture — Usually the cavitated films have an “orange peel” look after molding. The degree of “orange peel” is defined by the size of the air bubbles and the density of the film. The lowest density films (~0.55 gr/cm3) provide the highest effect. At upper levels of density, the label surface becomes smooth (~0.75 gr/cm3) and even glossy (above 0.85 gr/cm3). If this finished look is not desired, a solid- core BOPP or CPP will be used – white or clear, depending on the color of the container. Another widely used finish look is the satin-like soft touch surface. All of the above are usually dictated to the printer/ converter by the brand design and the molder. ● Converting and molding — BOPPs are stretched during their production to achieve the desired mechanical properties, while CPP is not. Thus, BOPPs are much easier to die-cut since they do not have much elasticity left in them. CPP is very difficult to work with during printing and die-cutting due to being very elastic and easily breakable. For the molding process, it happens in the exact contrary. BOPPs, thanks to being stretched during extrusion, tend to shrink back to their natural state inside the mold. On the other hand, CPP is very molding-stable and does not shrink at all. Introducing tiny air bubbles inside the film reduces drastically the shrinkage, thus cavitated BOPP is less shrinkable than the solid-core BOPP, making it more molder- friendly. ● Film cost — Cavitated BOPP costs less than solid-core BOPP, which costs less than CPP.
Table 3-1 Popular substrates
Manufacturer Name Film Cavitated Clear Injection Blow Thermo- Thickness Density forming [mic] [gr/cm3]
Treofan EUH BOPP Yes — Yes — — 40–75 0.55
EUP BOPP Yes — Yes — — 50–60 0.55
ELR BOPP Yes — Yes — — 70 0.88
ELW BOPP Yes — Yes — — 50 0.88
EWR BOPP — — Yes — — 57 0.96
ETR BOPP — Yes Yes — — 57 0.91
CWD CPP — — Yes — — 80–100 0.93
CTD CPP — Yes Yes — — 82 0.88
EPT BOPP Yes — — — Yes 60 0.55
EUT BOPP Yes — — — Yes 40 0.55
ENWW Substrates 9 Table 3-1 Popular substrates (continued)
Manufacturer Name Film Cavitated Clear Injection Blow Thermo- Thickness Density forming [mic] [gr/cm3]
Yupo LJR BOPP Yes — Yes — — 80 0.77
ITE BOPP Yes — Yes Yes — 105 0.76
AISE BOPP Yes — Yes Yes — 105 0.78
AIUE BOPP Yes — Yes Yes — 80–105 0.80
UAIB BOPP — Yes Yes Yes — 80–120 0.86
IZE BOPP Yes — — Yes — 105 0.77
ISF BOPP Yes — — Yes — 105 0.77
IDF BOPP — — — Yes — 80 0.93
IHC BOPP — Yes — Yes — 75 0.90
Taghleef LIM BOPP Yes — Yes — — 45–65 0.62 Industries LIX BOPP Yes — Yes — — 70 0.55
LIV BOPP Yes — Yes — — 76–90 0.64
LIG BOPP Yes — Yes — — 70 0.75
LIH BOPP Yes — Yes — — 70 0.82
For specific features, and best suitable film for your application, it is recommended to contact the film manufacturer representative in your area. Priming Printing on synthetic substrates using an HP Indigo digital press requires a primer layer to achieve a good bond between the ink and the film. The only films which do not require a primer are special pre-optimized substrates that are not used at all in the IML market. The primer layer plays a very crucial role in achieving good label performance during production and for end product durability. Thus, it is very important to select a suitable primer and pay special attention to its application on film. Parameters like primer chemistry, corona on film, primer coat weight (layer thickness), drying conditions and tensions – all may affect your production and end product.
Table 3-2 HP Indigo recommended primers for IML
Primer Manufacturer Inline/Offline Available for Solvent system Water resistance Thermal inline on resistance
DP050 Michelman Inline HP Indigo Water based Low High 20000
DP680 Michelman Inline HP Indigo Water based Low High WS6000 Series
ILP030 Michelman Inline HP Indigo Water based Moderate Moderate WS6000 Series
DP4453 Michelman Offline N/A Water based Moderate-high Moderate
10 Chapter 3 Production process ENWW The following are important primer application parameters: ● Corona on film Less is more! Since all the films are already provided with corona treated surface from the extruder, the main goal here is just “refreshing” the film surface (⇒ “bump” treatment). Time, humidity, storage conditions and contaminations affect the film surface treatment level and decrease the dyne levels, therefore it is very important to refresh the film with corona to allow for good priming and printing. However, over-treating and over-burning the film may introduce an unwanted effect. This will not be visible during the priming and printing, but it will decrease dramatically the durability of the end product, and especially the water/humidity resistance. For all applications, but especially for the ones requiring water/humidity resistance of the end product, it is highly recommended to use the lowest possible corona power. The best power level is “just enough” to allow good primer wetting of the substrate and good ink fixing, not more. HP Indigo's trials have showed that the best corona watt density level for refresh is about 10-30 W*min/m2. Use your equipment specifications to calculate the watt power if your system is working on predefined power and not density. For example, if you are using BOPP film on HP Indigo WS6000 Series Digital Presses, use 100-200W power in the ILP for corona “bump” treatment. For best results it is recommended to run a short trial to find the best corona levels on your equipment and materials. ● Coat weight Less is more! To achieve better drying, adhesion and durability, it is recommended to apply the lowest coat weight possible, “just enough” to allow for a good primer cover of the substrate, and good ink fixing. Also, most of the IML films are treated on both sides (print side and back side) to allow for better fixing during the molding. In case of offline priming, it is recommended to use a low coat weight also to avoid blocking. With high dyne levels on the back side, and a high primer coat weight, you may end up with a blocked roll after rewinding. The following are the coating parameters for HP Indigo recommended primers (listed in the table above): ◦ For offline standard flexo coating it is recommended to choose low volume anilox, such as 400-700 lpi (3.5-6.0 cm3/m2 volume). ◦ For inline on HP Indigo WS6000 Series Digital Presses, use standard coating settings (low or medium coat level). ◦ For inline on HP Indigo 20000 Digital Press, use low volume anilox (2.5 bcm). ● Drying conditions and tension Dimensional stability of the label for IML is highly important since after die-cutting, and until molding, the label has no backing liner and has to perform by itself, staying flat without any deformations or curling. BOPP film is quite sensitive and unstable under increased heat and tensions, thus it is highly recommended to use the lowest possible values. Since we use water based primers, hot air is needed to dry the primer. Using higher airflow may allow you to use lower temperatures. Depending on the primer chemistry, film and process parameters, the drying temperatures may range between 50 °C and 90 °C. For best results, it is recommended to run a short trial to find the best drying temperature and tension, according to your equipment and materials. ● Static To achieve a good IML production it is highly recommended to avoid static electricity, otherwise the labels will stick together and double-picking will be a major problem. Every process step must have
ENWW Priming 11 either a passive or an active static discharge station at the end. For priming, it is very important in case of offline coating. High static may introduce pin holes in the primer layer, causing print quality issues. ● Primer ageing There is a determined period of time during which you can still effectively print on primed film, before it becomes useless. It is irrelevant in case of inline coating, and very important for offline. Environment conditions (like humidity and temperature) and the primer chemistry will define how long a primed roll can wait before printing. To achieve better results, it is usually recommended to print as soon as possible (even on the same day), but some chemistries are more stable than others and remain reactive for days and even months. For more updated data on ageing of HP Indigo recommended primers (listed in the table above), contact Michelman's representative.
12 Chapter 3 Production process ENWW Printing Printing can be done on HP Indigo digital presses in either surface or reverse (mirror) modes. Most of the IML substrates are surface printed and later coated with a protective varnish. In case a very durable label is needed, you might choose to use overlay film for protection, or reverse printing on clear substrate (solid-core clear BOPP), and later laminating it to another BOPP. This method is rarely used since it adds additional materials and costs to production, and choosing the right varnish should provide you with the necessary protection and durability. Also, high injection temperatures might compromise the lamination interface and introduce bubbles or small delamination areas.
Recommended printing parameters for HP Indigo WS6000 Series Digital Presses: ● ILP (inline priming unit) — When using inline priming, use the parameters mentioned previously in Priming on page 10. When printing on offline pre-primed film, deactivate the ILP. No additional corona treatment is needed between the primer and the ink. ● Blanket = 105 °C; T2 = 200 kg; Fan = 8 V. ● Tensions (depending on the film thickness and properties): UW = 3-6 kg, ILP = 3-4 kg, Press = 5-10 kg, RW = 0.5-1 kg.
Recommended printing parameters for HP Indigo 20000 Digital Press:
● PUW (priming unwinder) — same as for ILP above. ● Blanket = 105–110 °C; T2 = 400–600 kg; Fan = 10 V. ● Tensions (depending on the film thickness and properties): UW = 6–8 kg, PUW = 6–8 kg, Press = 6–16 kg, RW = 3-4 kg. Due to the many variations in film thicknesses, densities and other properties, the above values should be seen only as a recommended starting point. Before starting production with a new material, it is recommended conducting a short test to find the best working parameters.
Important printing parameters:
NOTE: The following important parameters are recommended for all HP Indigo digital presses, although in this How-to Guide we focus on HP Indigo 20000 Digital Press and HP Indigo WS6000 Series Digital Presses.
● Scaling control Repeat Length (RL) is very important for every label printer, and IMLs are not any different. The RL is the length between the leading edge of one image/frame and the leading edge of the following image/ frame, usually defined by the die-cut plate size and marked by eye-marks. To allow precise and accurate die cutting, the RL must be controlled on the press during the printing. Pay special attention to this matter when printing on Cavitated BOPP since, due to its lower density, it is more sensitive to elongation and thus the RL is harder to control. The following are tips for an easier scaling control: ◦ When printing on a new substrate, always start with Scaling calibration wizard and substrate profiling on the HP Indigo digital press. This will automatically define the optimum press parameters for this film. Next time you print on this type of film, this step can be bypassed by choosing the film’s scaling profile that was previously saved. ◦ Depending on the press parameters you define, printing speed (number of separations) and film sensitiveness to elongation, you may still see some difference in RL from what you defined in pre- press. In this case, use the Manual Repeat Length Correction wizard on the HP Indigo digital press.
ENWW Printing 13 TIP: Design and add a special mark (for example a cross/star) to assist you with the RL correction, when 50% of it is on the trailing edge of frame#1 and 50% is on the leading edge of frame #2 (and so on…). This way you will clearly see if you have a problem with RL, allowing for a quick correction.
● Tension Tension control is very important during the printing, to allow good scaling and also avoid unwanted film deformations and curling. Usually, when having a scaling issue, a higher press engine tension might help. To avoid curling and film deformations it is highly recommended to set a lower rewinder tension. Figure 3-4 Printing on HP Indigo WS6800 Digital Press — Die-cut lines
TIP: Add those die-cut lines (indicated by the arrow in the figure above) only for about 20-30 meters at the beginning of a roll, so that the converter will be able to complete a quick and effective setup before the die- cutting. Finishing (varnish) Protective varnish coating is the most common finishing process for printed in-mold labels. In addition to protecting the ink on the end product, varnish coating has the following other roles: ● Ink protection against scuffing and scratching on the final container. Varnish also provides protection against water and chemicals (e.g., cosmetic products, dishwasher detergent). ● Ink protection against scuffing and scratching during IML production (die-cutting, stacking, transportation, molding). ● Chargeability – for injection molding process. Before labels are picked up they need to be totally discharged in order for the vacuum fingers to pick them up one at a time. The label is then charged with static electricity in order to be inserted into the mold and stay put until the injection. The varnish layer must provide that chargeability to the label. ● Varnish coating provides the low COF (coefficient of friction) which is very necessary during the die- cutting, so that the labels can be easily collected in a stack. A low COF is also important for the feed robot before the molding, to avoid double-picking. Due to the high performance and special requirements mentioned above, most varnishes for standard pressure-sensitive labels will not be suitable for IML. Most varnish manufacturers have special grades for the IMLs.
14 Chapter 3 Production process ENWW UV and water based are the varnishes most used for IML. Aqueous products are mostly food grade and typically used for perishables, but their performance and durability are limited. UV curable products are much more durable and provide better thermal and water resistance, but only some are food grade. In recent years, more and more manufacturers introduce low migration UV varnishes that are approved for food packaging. In addition to better performance, UV varnishes also allow faster converting. Most UV varnished labels can be die-cut, stacked and shipped after 12-24 hours, while aqueous solutions require a few days for curing.
The following are important varnish application parameters:
● Corona on film HP Indigo inks require corona treatment in order to achieve good bond with the varnish coating. Watt density should not be lower than 50 W*min/m2, but HP Indigo's testing showed best results with watt density of 60-80 W*min/m2. ● Coat weight A very important issue, coat weight not only affects the end product durability but also the performance throughout the production process: die-cutting and molding. On one hand, a higher varnish layer will provide better durability and protection, lower COF, better chargeability and better release from the mold – all the qualities you look for in IML. But on the other hand a thicker varnish layer will introduce unwanted mechanical forces and tensions, which the thin and unsupported label cannot withstand, and will result in tubing or curling after the die-cutting and during the molding. This is one of the most common failures in IML production and must be avoided. HP Indigo's testing showed that the target should be 2-5 dry gr/m2, however the optimum coat weight should be found for each product. ◦ For UV varnishes using flexo coating system, choose 150-300 lpi (8-20 cm3/m2 volume) anilox. ◦ For aqueous varnishes the coat weight would be usually lower, and anilox should be chosen according to the solids content. ● Curing/drying conditions and tensions To avoid set-off or blocking, the varnish must be completely cured/dry before the rewinding. To determine if your coating is dry enough you can use the simple test called “thumb twist”: press your thumb onto the coating and twist it while applying mild pressure. If you leave no markings or smears the coating is cured. To avoid over-burning the varnish and causing it to become brittle (common case with over-curing UV varnishes), it is recommended to control the UV lamp power and speed. To determine if the varnish is over-cured, perform this simple test: fold the label sample in two and run your fingernail on the fold line, then inspect the fold and look for varnish flakes and cracks. A good varnish should maintain its flexibility and not crack. Another important matter is maintaining mechanical stability and tensions between the film and the varnish layer, to avoid curling and tubing during the die-cutting and the molding. It is recommended to test and find the best tensions per specific materials (film and varnish) and per finishing equipment, but comparing to self-adhesive labels you should use lower-end tensions. Regarding the temperature, it is highly recommended to have a chiller roller after the UV lamp to cool down the film. For drying aqueous varnishes, it is recommended not to exceed the 90 °C limit. ● Static As mentioned for priming, it is highly recommended to avoid static electricity to achieve a good IML production, otherwise the labels will stick together and double-picking will be a major problem. Every process step must have either a passive or an active static discharge station at the end.
ENWW Finishing (varnish) 15 Table 3-3 Recommended varnishes for IML from popular suppliers
Varnish Manufacturer Chemistry Finish Food safe / low migration
IV044 Pulse Roll Label UV Gloss No Products
IV047 Pulse Roll Label UV Matt No Products
EL856 Pulse Roll Label UV Gloss No Products
EL207 Pulse Roll Label UV Matt No Products
L576 Paragon Inks UV Gloss N/A
62-785 Zeller & Gmelin UV Matt Yes
85-601781-9 Siegwerk UV Matt No
81-601575-4 Siegwerk UV Matt No
85-600391-8 Siegwerk UV Semi-Matt Yes
15-600611-6 Siegwerk WB Gloss Yes
EXC-90092 Toyo Ink Arets UV Gloss No
AQ42002 Actega WB Matt No
AQ42702 Actega WB Gloss Yes
AQ42706 Actega WB Gloss Yes
RGV001270 Actega UV Gloss No
RGV001364 Actega UV Gloss No
RGV001432 Actega UV Gloss No
RAVM00188 Actega UV Matt No
53770 Ashland UV Gloss No
52684 Ashland UV Gloss No
53006E Ashland UV Gloss No
NOTE: This list of varnishes was compiled from recommendations by our global finishing partners. Not all varnishes were tested and validated by HP Indigo. Please check for latest revisions of this document for the most updated list of products and validated materials by HP Indigo. NOTE: For regulatory aspects and more detailed information about the Food Indirect Compliance and Low Migration status of each material, HP Indigo recommends to contact the material supplier. For HP Indigo regulatory statement, please refer to Regulatory aspects on page 29.
16 Chapter 3 Production process ENWW Converting (die-cutting and stacking) After printing and finishing (mainly varnishing, but sometimes laminating), the next step is to convert the web to labels by die-cutting and stacking. Since the varnish (and the lamination adhesive) needs to cure before converting, the die-cutting machine is usually offline. The time required for curing depends on the chemistry, however with UV varnishes you may convert after as soon as 24 hours, while with WB varnishes it may take up to 1 week. (For more specific details, contact your varnish supplier). A standard die-cutting machine contains a rotary or semi-rotary magnetic die-cut unit, a shingle conveyer and a stacking module (see figure below). Optional add-ons may comprise a flexo coating station, an embossing unit, and a vacuum conveyer for faster production. Recent developments introduce the laser cutting option instead of the standard die-cut plates, although it is not very common in this somewhat conventional industry. The digital solution that HP Indigo provides can be a perfect case for laser cutting, cancelling the need to replace the die-cut plate per every different job. Since converting is the last station before the labels are shipped on to the molder site, it is highly important that the end stack of labels be totally free of static charge. Standard machines have anti-static bars before the die-cut unit and before the stacking module. Although it is recommended to apply static discharge at all IML production stations (priming, printing, finishing), usually this is the station where the most powerful discharge is applied, mostly by active discharge devices. The following figures show a manual stacking module for in-mold labels, and die-cut labels stacked and ready for shipment to the molder site. Figure 3-5 In–mold labels manual stacking module
ENWW Converting (die-cutting and stacking) 17 Figure 3-6 In–mold labels stacked and ready for shipment to the molder
NOTE: This method —called Cut-and-Stack— is the most used converting method. An additional method —called Cut-in-Place— was introduced following recent years developments and automation. With this method the labels are die-cut inline at the molding machine, and automatically placed inside the mold, thus allowing for a faster turnaround.
HP Indigo is partnering with 3 major die-cutting machinery manufacturers: Schober, Prati and Brotech. Following are the main products from each company that may suit to convert HP Indigo-printed IMLs: Schober ● RSM IML Entry level solution, web width up to 410 mm, die-cut up to 24". ● RSM IML Classic edition, web width up to 550 mm, die-cut up to 42". ● RSM IML Large format design, web width up to 850 mm, die-cut up to 48". Prati ● SATURN Omnia, web width up to 400 mm, die-cut up to 24". ● ALHENA, web width up to 530 mm, die-cut up to 28". Brotech ● CDF, web width up to 420 mm, die-cut up to 24". ● SDF, web width up to 520 mm, die-cut up to 24".
When choosing die-cutting equipment, the following parameters should be taken in consideration for best fit: ● web width ● die-cut length ● label size (min - max) ● varnish and other finishing capabilities (such as perforation) ● productivity and automation (speed, nesting, magnetic drum replacement, format combination) ● collection and stacking modules (TD vs MD ability, automatic vs manual)
18 Chapter 3 Production process ENWW Molding The finished labels usually reach the molding site in “cut & stack” state. Picking the label and placing it inside the mold is mostly done automatically, by robot. At this stage the labels must be totally discharged and have the desired COF, this way they will not get stuck to each other and pick & place can be performed easily. For Injection Molding, usually the robot picks the label and charge it up to ~15 kV, so that it becomes statically charged. This allows the label to be placed inside the mold and stay there. For Blow Molding, the mold designers usually place vacuum suction tunnels inside the mold, where the label sits, to allow better hold during the molding. The ink side of the label always faces the cold mold part. When molten plastic is introduced inside the mold at high temperature (for all techniques — injection / blow / thermoforming — the temperature is process and material dependent), only the back side of the label (few microns) melts and when quickly cooling down, it fuses together with the plastic container/cup. After the cycle is complete, the mold opens and the ready product is either placed on the conveyor (usually at blow molding), or picked up again by the robot and stacked on top of the container/cup created before it. Once the mold is open and the product is out, the robot quickly places a new label for the next cycle.
ENWW Molding 19 Injection Molding The injection molding process consists in injecting a heated and molten plastic polymer into a steel mold. The printed label is placed beforehand inside the same mold. When the label meets the molten polymer inside the mold, they fuse together. The mass then cools off and solidifies into the shape of the mold with the label fused to the container/part wall. Melting and injection temperatures of the plastic are in the range of 200 – 250 °C (depending on the type of plastic). For fast cooling of the material, the steel mold is usually chilled, and thus, the real temperature encountered by the label inside the mold is somewhat lower. The whole process is usually automated and lasts up to 5 seconds per injection. The injection molding process comprises the following steps (also indicated by the red balloons in the diagram below): 1. The charged die-cut label is placed in the mold. 2. The mold closes; molten polymer is injected from the extruder into the mold; the label fuses with the plastic. 3. The plastic cools down; the mold opens and the container/cup is ready together with the fused label. Figure 3-7 Injection molding process
1 Die-cut label 3 Extruder 5 Label fused to container
2 Label placed in the mold 4 Molten polymer injected into mold
20 Chapter 3 Production process ENWW Blow Molding Blow molding is a technique used for the production of hollow plastic parts such as bottles. The label is placed inside the steel mold beforehand. Then the pre-extruded hot plastic material (called “parison”) is introduced, and the two-parts mold closes on it. With heated and high pressurized air (“blowing”) the plastic is stretched into the shape of the mold, and is fused together with the label placed at the mold’s walls. The process temperature of the molten plastic is a bit lower than in the injection molding process, being in the range of 180 – 200 °C (depending on the type of plastic; there are some special grade films that can be blow-molded at very low temperatures of 120-130 °C). For fast cooling of the material, the steel mold is usually chilled, and thus, the real temperature encountered by the label inside the mold is somewhat lower. The whole process is usually automated and lasts up to 10 seconds per part (depending on the size). The blow molding process comprises the following steps (also indicated by the red balloons in the diagram below): 1. The die-cut label is placed in the two-parts mold, on both walls. 2. Vacuum suction holds the label in place; the parison is introduced between the two open mold parts. 3. The mold closes; heated high pressurized air is blown inside the parison, expanding it towards the mold walls until it acquires the shape of the mold; the label fuses with the plastic. 4. The plastic cools down; the mold opens and the bottle is ready together with the fused label. Figure 3-8 Blow molding process
1 Die-cut label 3 Parison 5 Label fused to container
2 Label placed in the mold (on both 4 High pressurized air walls)
ENWW Molding 21 Thermoforming During thermoforming, unlike the injection and blow techniques, the thermoplastic molding material (in web or sheet state) is fed into the molding press. The process uses heat and pressure to shape the material. As for the other molding processes, the label is placed inside the mold beforehand, and when it meets the heated polymer inside the mold, they fuse together. The mass then cools off and solidifies into the shape of the mold, with the label fused to the container/part wall. The process temperatures of the plastic here are the lowest of all molding processes, being in the range of 130 – 150 °C (depending on the type of plastic). For fast cooling of the material, the steel mold is usually chilled, and thus, the real temperature encountered by the label inside the mold is somewhat lower. The whole process is usually automated and lasts up to 5 seconds per part. Due to the lower process temperatures and pressure, compared to the other techniques, it is highly recommended to NOT use standard IML substrates used for injection or blowing, to avoid the resulting poor adhesion. This was the major obstacle for the thermoforming process in the past. In recent years many label films were developed specifically for thermoforming labeling (for example, coex PP, which solved the adhesion issue by including a special low-melting PP layer), but at a somewhat higher cost. This may be the reason why this technique still has the lowest market share among the in-mold labeling production processes. The thermoforming process comprises the following steps (also indicated by the red balloons in the diagram below): 1. The die-cut label is placed in the mold. 2. The thermoplastic web/sheet is preheated before entering the mold; the softened plastic enters the mold; the mold closes, shaping the plastic to it; the label fuses with the plastic. 3. The plastic cools down; the mold opens and the container/cup is ready together with the fused label. Figure 3-9 Thermoforming process
1 Die-cut label 3 Heat 5 Closed mold
2 Label placed in the mold 4 Thermoplastic web 6 Label fused to container
22 Chapter 3 Production process ENWW Examples of E2E (end-to-end) process Injection molding
Table 3-4 Product description and required properties and finishing
Product White PP container for food, 500cc
Two labels: body (conic) + lid (round)
Properties Resistance to scuff/rub and humidity
Thermal resistance at the gate area (lid label)
Finishing White “orange peel” label
Table 3-5 Example of recommended materials and process parameters
Film EUP from Treofan, white cavitated BOPP, 60 microns
Primer DP050 from Michelman
Priming Inline on HP Indigo 20000 Digital Press:
Anilox: 2.5 BCM Corona: 400 Watt Dryer: 70 °C
Printing on HP UW tension: 9 kg ILP tension: 9 k Print tension: 10 kg Indigo 20000 Digital Press RW tension: 6 kg Blanket: 110 °C T2: 600 kg
Varnish IVO44 from Pulse (UV based)
Varnishing Corona on ink: 60 W*min/m2 Anilox: 12 cm3/m2 volume (200 LPI)
Injection Resin temp: 220 °C Cycle time: 3–5 seconds
ENWW Examples of E2E (end-to-end) process 23 Blow molding
Table 3-6 Product description and required properties and finishing
Product Opaque HDPE bottle, 1000cc
One label: body (rectangular)
Properties Water, chemical and scuff/rub resistance
Finishing White glossy label
Table 3-7 Example of recommended materials and process parameters
Film IDF from Yupo, white solid core BOPP, 80 microns
Primer DP4453 from Michelman
Priming Offline on the ABG Digicon series II:
Anilox: 5 cm3/m2 volume (400 LPI) Corona: 26 W*min/m2
Dryer: 70 °C Speed: 30 m/min
Printing on HP UW tension: 4 kg ILP tension: 4 k Print tension: 8 kg Indigo WS6800 Digital Press RW tension: 1 kg Blanket: 105 °C T2: 200 kg
Varnish Toyo Ink Arets 90092 (UV based)
Varnishing Corona on ink: 80 W*min/m2 Anilox: 12 cm3/m2 volume (200 LPI)
Blowing Process temp: 120 °C Cycle time: 20 seconds
24 Chapter 3 Production process ENWW 4 Quality assurance and best practice
Issues affecting IML end product quality and production process The following are the main issues that can affect the quality of IML end product and the production process. ● Blocking IML substrates usually come with corona treatment on the back side to allow good bonding during injection or blowing. This may attract also the primer or the varnish layer to the back side. Make sure your coating is completely dried or cured. Also low rewinding tensions are recommended. ● Static charge inside the final stack Static charge could lead to double-picking during the feeding process from the labels magazine. Also poor label placement inside the mold can occur. Most IML varnishes are optimized to be chargeable or dissipative for static electricity. Check your varnish data sheet for those properties or contact your supplier. Too low coat weight of the varnish may also affect the chargeability efficiency. ● COF not in required range COF (coefficient of friction) in the wrong range could introduce problems during stacking, and later during the picking & feeding into the mold. Just like with antistatic properties, most IML varnishes are optimized to provide suitable COF values, usually in the range of 0.15-0.20. Working with not suitable varnish, or applying too low coat weight, may affect the COF negatively. ● Double-picking from the stack Blocking, high static or wrong COF can cause double-picking during the feeding from the labels magazine to the mold. This is a big issue production-wise since it will require to stop the machine and clean the feeder or the mold. ● Curling or tubing after die-cut Also this issue will cause problems during picking labels from the magazine, since a curled label will be hard to pick by the vacuum fingers. The following can be reasons for curling: ◦ Film structure — The multi-layer structure of IML film introduces different mechanical properties per each layer. Heat and tensions applied on the film during production affect those layer differently. As a result, the equilibrium between the layers might be distorted and the label will curl. Some films are more resistant to curling than others. Usually, the voided low density films are more mechanically stable and tend to curl less than the solid-core high-density films. This is the reason voided films are used more for injection applications with smaller label size, because there the curl can be more “hurtful”. For large size containers/labels and blowing technology, the films are mainly solid-core. ◦ Tensions and temperatures — As stated above, these two external parameters can affect dramatically the film’s behavior. It is highly recommended to work at the lowest possible tensions to drive and wind the film, and also at the lowest possible temperatures to just enough dry/cure the coatings. In case of UV varnish curing, it is very important to place a chilling roller right after the UV lamp to cool down the film. ◦ Varnish — This coating layer is quite thick and may introduce unwanted tensions to the upper layer of the film, and eventually cause curling. Mostly it can happen with UV varnishes (very rare with WB chemistry), since they tend to shrink after curing. The keys to avoiding the curling from
ENWW Issues affecting IML end product quality and production process 25 the varnish layer are controlling the coat weight (not too high), and not over-curing the varnish (so to maintain its flexibility). ◦ Graphics — Designing your graphic job correctly also may help with avoiding the curling. Having very high ink coverage at certain areas (for example on the edges), and no ink at all nearby (for example in the center), may introduce some different tension zones in the label which may cause curling after die-cut (see example in the figure below). It is always recommended to have your graphic job without any drastic changes/steps in coverage. Figure 4-1 Die-cut labels, curling due to high roll tension
● Inability to hold (for injection) / dissipate (for blowing) static charge Most IML varnishes are optimized to be chargeable or dissipative for static electricity. Check your varnish data sheet for those properties, or contact your supplier. A too low coat weight of the varnish may also affect the efficiency of chargeability. ● Sticking to the mold walls – bad release This is a very common problem with the high temperatures of the injection process, when the varnish/ ink sticks to the mold walls and cannot be released correctly. Check the following to avoid this issue: ◦ Mold temperature — The mold must be cooled during the process. ◦ Varnish curing level — Uncured varnish will be tacky and sticky at the “thumb twist” test (see “Curing/drying conditions and tensions” under Finishing (varnish) on page 14). ◦ Varnish grade — Most IML varnishes are optimized with high release additives. Verify that you are using the right grade. ◦ The mold is not clean ◦ Injection temperature is too high ◦ Dwell time is too long ● Color change or ink washout near the gate after injection The gate area is one of the most failure-prone areas in injection in-mold labels production. The gate area is where the pressure and the temperature are the highest. The printed image has the film backing for protection and the mold cooling for relative thermal insulation, but sometimes those are not sufficient. Check or test the following to avoid this issue: ◦ Mold temperature — The mold must be cooled during the process. ◦ Injection parameters — Try lowering the injection temperatures and increasing dwell times. ◦ Film construction — Cavitated films have much better thermal insulation than solid-core films. If possible, try a highly voided film (lower density). ◦ Film thickness — If possible, try a higher thickness film (do not increase density).
26 Chapter 4 Quality assurance and best practice ENWW ◦ Graphics — If possible, design your image so that no ink will be above the gate area. If not possible, try at least lowering the ink coverage. ◦ Gate design — Optimize your gate geometry. Proper lens around the gate area have proved to be less aggressive. ● Poor bonding between label and plastic container / delamination The IML films are specifically designed to bond well with the molten injected plastic, or the parison, during blowing. These films have a special outer layer to be easily melted and joined with the container. Sometimes we see imperfect adhesion, either locally or along the whole label. Check or test the following to avoid this issue: ◦ Films may not melt and bond with the plastic as required, if their grade was selected improperly, or if they are old or were not stored properly. Consult your film supplier for grade and storage recommendations. ◦ Primer / ink / varnish that are not dried/cured properly and rewinded with a too high pressure may set-off to the back side during one of the production stages. This contamination may affect the label-container interface adhesion. ◦ Process parameters – try increasing the temperature and the dwell time. ◦ Migration of filled goods/product through the container walls after filling. ● Container deformation Usually happens when injecting thin-wall containers while using solid-core thick labels. As stated above, solid-core materials have a higher tendency to curling and uneven tensions/shrinkage. These tensions may overpower the container wall mechanical stability (especially with thin and large area walls or lids) and introduce deformations. It is highly recommended to use cavitated thin films for such applications. Standard quality tests for labels and end product ● Tape test / Peeling For ink adhesion testing use 810 3M scotch tape. For varnish adhesion use 610 3M scotch tape. Apply the tape on the label and run 2-10 strokes with a 2 kg weight roller. Remove the tape in one continuous motion. Check for ink/varnish removal. This test can be done after the printing, varnishing, or on the end product. It may also be performed in conjunction with freezing or water immersion tests.
NOTE: Varnishes used for IML applications are usually High Slip and Low COF, which can very much mask the tape peeling results because the tape will not bond well to the surface and you will receive a false positive result. In this case, it is recommended to perform the other tests listed below.
● Lay Flatness / Curling This test will allow you to measure the tendency of the corners or edges of a label to curl. Cut a 10 x 10 cm cross on the web, and measure the elevation of the corners. Usually the requirement is to have a curl of below 3-5mm . Perform this test on fully cured varnish (at least 24 hour after the coating), since UV varnishes tend to shrink after curing and contribute to the curling. ● Scratch resistance This test measures the resistance of the varnished label against scratches from sharp objects. The test can be done either on automatic equipment or with a manual tester. The pressing force should not exceed 3N. This test must be performed on fully cured varnish. It can also be performed in conjunction with freezing or water immersion tests.
ENWW Standard quality tests for labels and end product 27 ● Abrasion / Rub / Scuff resistance This test measures the resistance of the varnished label against scuffing. Use a standard rub tester with lapping film and 2 kg weight. Can be performed in conjunction with freezing or water immersion tests. ● Crinkle / Crease Useful test especially when the label on the end product is not flat but needs to cover some edges or corners. Typically performed in conjunction with the following: scratch, scuff, freezing and water immersion. Check for ink/varnish removal in the folds areas. ● Freeze Great simulation test for dairy products application. Place your label, or end product container, inside the freezer at -4 °C for up to 24 hours. Take it out and allow 10 minutes for humidity to condense on the label surface. Check for ink/varnish removal with peeling, scratch and rub tests.
● Water immersion Useful test for applications requiring direct water resistance. Immerse the label, or the end product container, in water for up to 1 hour. Take it out and dry the surface with paper or cloth. Immediately check for ink/varnish removal with peeling, scratch and rub tests. This test can be performed in conjunction with the crinkle test prior to water immersion. ● Chemical / Product resistance Useful test for personal hygiene products and household detergents. Apply your chemical (solvent, oil, shampoo, cream, etc.) on the label surface. In case of fast evaporating solvent, cover with glass plate. Wait for 5-15 minutes and then remove the cover and clean/absorb the chemical. Check for ink/varnish removal. ● Dishwasher Many high-end products like lunch boxes or multiple-use storage containers will be placed and washed inside a dishwasher. In addition to standard water immersion, chemical resistance and freeze testing, many companies require real-life dishwasher testing. Usually 50-150 washing cycles will be followed with standard scratch and peeling. ● Microwave Many food containers for "ready food" —that only require heating before the consumption— will be microwaved. It is recommended to test your materials and final IML container for microwave resistance. ● Blocking Tested by placing a weight (up to 4 kg/cm2) on top of a stack of labels for 24 hours. Check for blocking – the labels should not show any tendency to stick to each other in the stack. ● Chargeability Useful test to measure the time the label can withhold the required static charge and stay in the mold without moving. It is useful for maximum cycle time measurement. Charge your label up to 15 kV with a charging bar, and measure the time the label stays vertically attached to a metal plate or the mold.
28 Chapter 4 Quality assurance and best practice ENWW Regulatory aspects The status of HP Indigo ElectroInk for printing food packaging applications can be found in the white paper HP Indigo for Food Packaging Printing Regulatory Overview (4AA4-8153ENW, February 2015). (Contact customer care for this document). This document provides details on the status of HP Indigo ElectroInk under key worldwide regulations for food contact materials, and well-defined conditions of use. In-mold labels (IML) are not specifically referred to in this White Paper and, notwithstanding the fact that HP Indigo ElectroInk is not intended for direct food contact, it can be used in IML applications under well-defined conditions of use, provided that the proper risk assessment is performed. In general, IMLs will be surface-printed and then overcoated with an overprint varnish to provide protection and aesthetic appeal to the printed label. In case of food containers, this varnish would need to be approved for direct or indirect food contact and low migration. Customers can perform their own risk assessment of IML applications by considering the possibility of the following risks: 1. Migration from the printed surface through the label and container. 2. Set-off inside the winded roll from the printed surface to the back side of the film, and then migration through the container after molding. 3. Set-off inside the stacked labels after die-cutting, from the printed surface to the back side of the label, and then migration through the container after molding. 4. Set-off inside the stacked cups/containers from the printed surface to the inside food contact surface of the neighboring cup/container. Please consider this risk with highest priority since the molded cups/ containers are often stacked with high rub and friction which can increase the risk of set-off. HP Indigo will provide information on HP Indigo ElectroInk to the customer and customer's laboratory to allow a proper risk assessment to be performed. All regulatory information about other materials, such as the primer, varnish, label film and molded plastic resin should be provided by each manufacturer/supplier. HP Indigo is not responsible for materials and processes that are beyond its control. HP Indigo recommends that its customers perform their own risk assessment and regulatory compliance determination of their product.
ENWW Regulatory aspects 29 A Obtaining customer support
Materials Application Team (MAT) The Materials Application Team (MAT) provides customer support in matters related to flexible packaging materials, application development and troubleshooting. The MAT is always available to address your questions via e-mail.. The following table lists the contact details for the Materials Application Team.
Region First name Last name E-mail address
WW Carmit Havkin-Reem [email protected]
WW Pasha Solel [email protected]
EMEA Patrick Eagle [email protected]
APJ Patrick NG [email protected]
NA Keith King [email protected]
My HP Indigo Information about supplies and media for HP Indigo Labels and Packaging presses is available to HP customers on My HP Indigo portal. ● Go to: https://myhpindigo-int-pro.houston.hp.com/SuppliesBusinessManagement/Pages/default.aspx. ● Select the relevant topic to display the available information, including technical documentation, media partners, finishing solutions and more. RIT’s HP Indigo Over-Print Varnish (OPV) performance program The HP Indigo Over-Print Varnish Performance (OPV) program is a UV and WB (water base) varnishes evaluation and validation program, performed by the Printing Applications Laboratory of the RIT (Rochester Institute of Technology). Multiple varnishes from different suppliers are tested for their performance with HP Indigo ink. The varnishes go through the following tests: peeling, mechanical wear, optical test, heat resistance and UV ageing. For more information on the HP Indigo OPV performance program: ● Go to: http://printlab.rit.edu/services/opv-new/ ● Select a manufacturer/supplier to display the list of tested varnishes and the related technical documentation.
30 Appendix A Obtaining customer support ENWW Suppliers and vendors list The following tables list the contact details for our suppliers of films, primers and varnishes, and die-cutting equipment vendors.
Table A-1 Films suppliers
Supplier Address Country Tel. Website
Treofan 6001 Gun Club Rd. Winston-Salem, USA +1 336 776 9448 www.treofanamerica.com NC 27103
Av. Colorines No. 255 Zacapu, Mexico +52 436 363 9165 www.treofanamerica.com Michoacan, C.P. 58600
Am Prime Parc 17 66479 Raunheim Germany +49 6142 200 2000 www.treofan.com
Yupo Shinochanomizu Bldg., 15F 4-3 Japan +81-(0)3-5281-0811 japan.yupo.com Kanda-surugadai Chiyoda-ku, Tokyo 101-0062
800 Yupo Court, Chesapeake, VA USA +1-757-312-9876 www.yupousa.com 23320
Willstätter Strasse 30 D-40549 Germany +49 (0)211 520 54 30 www.superyupo.com Düsseldorf, Germany
Taghleef 2751 Centerville Road - Suite 400, USA +1 302 326 5500 www.ti-films.com Industries Wilmington (DE) 19808
Lou Shan Guan Road 83, 2608, Fl 26 China + 86 21 3133 2608 www.ti-films.com New Town Center Building, Shanghai
11 Moloney Drive - Wodonga Victoria Australia +61 2 60 220 220 www.ti-films.com 3690
Reutig 2, D-56357 Holzhausen an der Germany +49 6772 9676 011 www.ti-films.com Haide
Via E. Fermi, 46 - 33058 San Giorgio Italy +39 0431 627 111 www.ti-films.com di Nogaro (Udine)
Avenida de Iberoamérica, 56 - 23680 Spain +34 953 59 81 00 www.ti-films.com Alcalá la Real, Jaén
Table A-2 Primers suppliers
Supplier Address Country Tel. Website
Michelman 89d Rue Pafebruch 8303 Capellen Luxemburg +35 226 394433 www.michelman.com
9080 Shell Road Cincinnati, OH USA +1 513 686 2702 www.michelman.com 45236-1299
1 Tuas Avenue16 Singapore 638924 Singapore +65 6861 2822 www.michelman.com
Table A-3 Varnishes suppliers
Supplier Address Country Tel. Website
Actega Terra Industriestraße 12 31275 Lehrte Germany +49 5132 5009-0 www.actega.com (Altana Group)
ENWW Suppliers and vendors list 31 Table A-3 Varnishes suppliers (continued)
Supplier Address Country Tel. Website
Actega Kelstar 950 S. Chester Avenue, Suite B2 USA +1 856 829-6300 www.actega.com (Altana Group) Delran, NJ 08075
Toyo Ink Arets IND PARK KREKELENBERG Belgium +32 (0)3 880 67 67 www.toyoinkarets.com TUNNELWEG 3 2845 NIEL
PASEO DE LOS ADOBES 1081, Mexico +52 33 3627 11 45 www.toyoinkarets.com BODEGA 4 COL. GUADALAJARA TECHNOLOGY PARK CP 45019 ZAPOPAN JALISCO
3 ANSON ROAD #27-01 SPRINGLEAF Singapore +65 94 57 55 49 www.toyoinkarets.com TOWER 079909 SINGAPORE
Ashland 5200 Blazer Parkway Dublin, OH USA +1 614 790 3361 www.ashland.com 43017
Vale Industrial State Kidderminster UK +44 1562 821 300 www.ashland.com DY11 7QU
18TH Floor, 1089 Zhongshan No. 2 China +862124024888 www.ashland.com Rd. (S), Xuhuiyuan Bldg. Shanghai
Paragon Inks Brocks Way East Mains Ind. Estate UK +44 1506 853 535 www.paragoninks.co.uk Broxburn EH52 5NB
6 Little Brook Road West Wareham USA +1 508 322 7988 www.paragoninks.co.uk MA 02576
Pulse Roll Label Unit 1, Nibley Business Park Nibley UK +44 1454 272 433 www.pulserl.com Products Lane, Yate Bristol BS37 5HL
Squid Inks Welschloh 299 CH-8965 Berikon Switzerland +41 566 488 535 www.squidinks.ch
Sun Chemical / WATERRAS TOWER, 101, Kanda Japan +81 3 6733 3000 www.dic-global.com DIC Corporation Awajicho 2- chome, Chiyoda-ku, Tokyo 101-0063
35 Waterview Boulevard, Parsippany, USA +1708 236 3798 www.sunchemical.com NJ 07054-1285
Framewood Road, Slough, SL3 6PJ UK +44 203 139 000 www.sunchemical.com
Table A-4 Die-cutting equipment vendors
Supplier Address Country Tel. Website
Schober Industriestraße 2, 71735 Eberdingen Germany +49 7042 7900 www.schobertechnologies.de Technologies GmbH
Prati Via Deruta 2, 48018 Faenza Italy +39 0546 46889 www.praticompany.com
Brotech 1st Floor, 8th Building, TongFuYu China +86 755- 83733867 www.bro-tech.net Graphics Industrial Park, YongHe Road, Fuyong town, Baoan District, Shenzhen 518103
32 Appendix A Obtaining customer support ENWW B Related documentation
The following documents provide additional information about primers and overprint varnishes (OPV) for HP Indigo Labels and Packaging Digital Presses. They are available from My HP Indigo portal at: https://myhpindigo-int-pro.houston.hp.com/Pages/default.aspx You can also follow the direct links below: ● Substrate optimization and priming guidelines for HP Indigo Labels and Packaging Digital Presses How- to Guide (CA394-05492): https://myhpindigo-int-pro.houston.hp.com/Technical/TechnicalDocuments/ CA394-05492.pdf ● Selecting Varnishes and Over-Lamination for HP Indigo Labels & Packaging Digital Presses How-to Guide (CA394-07950): https://myhpindigo-int-pro.houston.hp.com/Technical/TechnicalDocuments/ CA394-07950.pdf ● Operating the Inline Primer for HP Indigo WS6000 Series Digital Presses User Guide (CA394-11323): https://myhpindigo-int-pro.houston.hp.com/Technical/TechnicalDocuments/CA394-11323.pdf
ENWW 33 CGlossary
Terms and acronyms
NOTE: Terms are ordered alphabetically. Text in italics points to another term in this glossary.
Term Description
ABS Acrylonitrile Butadiene Styrene – used for long-life products such as lunch boxes (see IMD).
Activation temperature Temperature at which the back side of the label becomes tacky and ready to adhere to the molded part.
Anilox roller Engraved primer/varnish metering roll used in flexo coaters to provide a controlled amount of coating to the rubber/transfer roller which applies the coating onto the substrate.
Basis weight The weight of a known area of substrate, usually in gr/m2 or pounds/ream.
Bleeding Printing defect on the label, where edges are not uniform and the ink appears to bleed into an adjacent area (i.e. extends beyond the label edge).
Biaxial orientation Orientation of plastic films in both machine and cross machine (transverse) directions by stretching. Biaxially stretched films are generally well balanced in both directions and much stronger in terms of tear strength.
Blistering A form of delamination that is a void or pocket which appears as bulge on the surface of the label after injection molding. It is often caused by the pressure of gasses created in the injection molding process.
Blocking The tendency of two plies of substrate to stick together in a stack or roll, especially under heat and/or pressure.
Blow molding Manufacturing process by which hollow plastic parts are formed. The process begins with melting down the plastic and forming it into a parison (or preform) which is then clamped into a mold and air is blown into it to push the plastic out to match the mold. It is one of the main types of In-Mold Labeling.
BOPP Bi-axially oriented polypropylene (also PP).
Caliper Substrate thickness expressed in mils or microns (1 mil = 25.4 microns).
Cast film Polyolefin film, usually polypropylene, which is not oriented after it is extruded.
Cavitated film A co-extruded film consisting of a partially foamed or "cavitated" inner core layer, and thin solid outer layers. This “sandwich” is much stronger, has better stiffness and has a higher yield than a solid mono-layer film of the same caliper.
Cling A very mild form of blocking where the plies can be easily separated without visible damage to either surface.
Co-extrusion (COEX) Simultaneous extrusion of two or more different thermoplastic resins into a sandwich-like film with clearly distinguishable individual layers.
COF (Coefficient of Friction) A measurement of “slipperiness” of plastic films and laminates (i.e., the force required to slide a film surface over another film surface).
Corona treatment A treatment used to alter the surface of plastics and other materials to improve bonding with printing inks, coatings, and adhesives.
CPP Cast polypropylene.
34 Appendix C Glossary ENWW Term Description
Curing Process that transforms a pre-polymer (resin) into a thermoplastic polymer via cross-linking.
Curl Label defect where a label edge or corner does not lay flat on a plane surface.
Cut in Place (CIP) A device at the molding site that cuts labels from a web and place them directly in a mold.
Delamination When the appliqué or label does not adhere to the plastic substrate to any degree.
Die-cutting Using a sharp device (e.g., die) to cut labels from printed sheets or web.
Double picking Two or more labels which are stuck together when fed from a magazine stack.
Extrusion The process of forming a thermoplastic film, container, or profile by forcing the polymer melt through a shaped orifice.
Injection molding Manufacturing process for producing parts by injecting material into a mold.
Film One layer or more [coex] of plastic material, without lamination between them.
Flagging Label defect where edges are lifted from a container.
FMCG Fast-Moving Consumer Goods - Products that are sold quickly and at relatively low cost. Examples include non-durable goods such as soft drinks, toiletries, and grocery items.
Gate The orifice through which resin flows from the runner to the part. This orifice could take various forms depending on the part design requirements.
Gauge Thickness of plastic film measured in decimal inches or mils (North America), or microns (Europe). Quick equivalency equation: 1 mil = 25.4 microns.
Hot tack Strength of a still-molten bond immediately after pressure is released.
IMD (In-Mold Decoration) Type of in-mold labeling (IML), but for durable goods like car dashboards and electronics.
IML (In-Mold Labeling) The use of paper or plastic labels during the manufacturing of containers by blow molding, injection molding, or thermoforming processes.
Ink wash An area on a label where the ink has been moved around or destroyed by heat, friction, or pressure from the injection molding process. Usually it can be seen at the gate area.
Machine direction (MD) The direction in which film moves through the packaging equipment.
Mandrel Part that transfers the label to the female side of mold.
Migration Diffusion of molecules out of a package into the contained product (e.g., food) or vice versa.
Mold release Additive in plastic resin (both container and varnish) which prevents molded container or part from sticking to the mold.
OPV Over Print Varnish - Clear coated layer used to protect the ink.
Orange peel Textured or micro-pitted label surface appearance resembling the surface of an orange. Usually caused by partial collapse of the cavitated film core during molding.
Parison Tube of molten plastic (extended from extruder) with a hole in one end through which compressed air can pass. It is captured by the closing mold in the blow molding process.
Pick and place Articulated robotic device which picks up a label from the magazine stack and positions it in the open mold.
Polycarbonate (PC) A particular group of thermoplastic polymers which are easily worked, molded, and thermoformed.
Polyethylene (PE) Made in high density, low density, linear low density and metallocene variations (LDPE, LLDPE and HDPE). Most used material for containers in blow molding.
ENWW Terms and acronyms 35 Term Description
Polyethylene Terephthalate Tough, temperature resistant polymer. Polyester film is a staple of multi-layer packaging for a (Polyester) (PET) wide variety of applications.
Polyolefin Family of polymers (plastics) derived by ethylene and propylene, such as Polyethylene (PE) and Polypropylene (PP).
Polypropylene (PP) Soft and clear but brittle at low temperatures. This property as well as stiffness, strength and clarity is improved by orientation. See: BOPP.
Polystyrene (PS) Used in Decoration Molding. See IMD.
Primer A coating applied over a substrate for the purpose of improving an ink or an adhesive bond.
PSL Pressure-sensitive label.
Release liner Paper or film carrier for heat transfer or pressure-sensitive labels.
Release solvent Solvent or water trapped in a coating, adhesive or ink.
Rotary die-cutting Off-press process of punching out individual labels using sharpened rules mounted on a support bed. See also: die cutting.
Runner The channel in the mold body through which the resin flows to the part.
SAL Self-adhesive label (see PSL).
Slip The ability of film to move easily over hard plastic, metal, or ceramic platforms or against another piece of film.
Thermoforming A method of forming plastics where a plastic sheet is heated to a point where it is soft and formable.
Transverse direction (TD) The direction perpendicular to the machine direction.
Vacuum port Small openings in the mold which hold labels in place during blow molding.
36 Appendix C Glossary ENWW DRecycling codes
Recycling codes
Packaging Code Description Properties Recycled products applications
Polyethylene Terephthalate (PET). PET is Clarity, strength, Plastic soft drink, Fiber, tote bags, clothing, film clear, tough, and has good gas and toughness, water, sports and sheet, food and beverage moisture barrier properties. Commonly barrier to gas and drink, beer, containers, carpet, strapping, used in soft drink bottles and many moisture, mouthwash, fleece wear, luggage and injection molded consumer product resistance to catsup and salad bottles. containers. Other applications include heat. dressing bottles. strapping and both food and non-food Peanut butter, containers. Cleaned, recycled PET flakes pickle, jelly and and pellets are in great demand for jam jars. Oven- spinning fiber for carpet yarns, producing able film and fiberfill and geo-textiles. Nickname: oven-able Polyester. prepared food trays.
High Density Polyethylene (HDPE). HDPE Stiffness, Milk, water, juice, Liquid laundry detergent, is used to make bottles for milk, juice, strength, cosmetic, shampoo, conditioner and water and laundry products. Unpigmented toughness, shampoo, dish motor oil bottles; pipe, bottles are translucent, have good barrier resistance to and laundry buckets, crates, flower pots, properties and stiffness, and are well chemicals and detergent bottles; garden edging, film and sheet, suited to packaging products with a short moisture, yogurt and recycling bins, benches, dog shelf life such as milk. Because HDPE has permeability to margarine tubs; houses, plastic lumber, floor good chemical resistance, it is used for gas, ease of cereal box liners; tiles, picnic tables, fencing. packaging many household and industrial processing, and grocery, trash chemicals such as detergents and bleach. ease of forming. and retail bags. Pigmented HDPE bottles have better stress crack resistance than unpigmented HDPE bottles.
Vinyl (Polyvinyl Chloride or PVC). In Versatility, Clear food and Packaging, loose-leaf binders, addition to its stable physical properties, clarity, ease of non-food decking, paneling, gutters, PVC has excellent chemical resistance, blending, packaging, mud flaps, film and sheet, good weatherability, flow characteristics strength, medical tubing, floor tiles and mats, resilient and stable electrical properties. The toughness, wire and cable flooring, cassette trays, diverse slate of vinyl products can be resistance to insulation, film electrical boxes, cables, traffic broadly divided into rigid and flexible grease, oil and and sheet, cones, garden hose, mobile materials. Bottles and packaging sheet are chemicals. construction home skirting. major rigid markets, but it is also widely products such as used in the construction market for such pipes, fittings, applications as pipes and fittings, siding, siding, floor tiles, carpet backing and windows. Flexible vinyl carpet backing is used in wire and cable insulation, film and window and sheet, floor coverings synthetic frames. leather products, coatings, blood bags, medical tubing and many other applications.
ENWW Recycling codes 37 Packaging Code Description Properties Recycled products applications
Low Density Polyethylene (LDPE). Used Ease of Dry cleaning, Shipping envelopes, garbage predominately in film applications due to processing, bread and frozen can liners, floor tile, furniture, its toughness, flexibility and relative strength, food bags, film and sheet, compost bins, transparency, making it popular for use in toughness, squeezable paneling, trash cans, applications where heat sealing is flexibility, ease of bottles, e.g. landscape timber, lumber. necessary. LDPE is also used to sealing, barrier to honey, mustard. manufacture some flexible lids and moisture. bottles and it is used in wire and cable applications.
Polypropylene (PP). Polypropylene has Strength, Catsup bottles, Automobile battery cases, good chemical resistance, is strong, and toughness, yogurt containers signal lights, battery cables, has a high melting point making it good resistance to and margarine brooms, brushes, ice scrapers, for hot-fill liquids. PP is found in flexible heat, chemicals, tubs, medicine oil funnels, bicycle racks, and rigid packaging to fibers and large grease and oil, bottles. rakes, bins, pallets, sheeting, molded parts for automotive and versatile, barrier trays. Thermometers, light consumer products. to moisture. switch plates, thermal insulation, egg cartons, vents, desk trays, rulers, license plate frames, foam packing, foam plates, cups, utensils.
Polystyrene (PS). Polystyrene is a Versatility, Compact disc Thermometers, light switch versatile plastic that can be rigid or insulation, clarity, jackets, food plates, thermal insulation, egg foamed. General purpose polystyrene is easily formed. service cartons, vents, desk trays, clear, hard and brittle. It has a relatively applications, rulers, license plate frames, low melting point. Typical applications grocery store foam packing, foam plates, include protective packaging, containers, meat trays, egg cups, utensils. lids, cups, bottles and trays. cartons, aspirin bottles, cups, plates, cutlery.
Other. Use of this code indicates that the Dependent on Three and five Bottles, plastic lumber package in question is made with a resin resin or gallon reusable applications. other than the six listed above, or is made combination of water bottles, of more than one resin listed above, and resins. some citrus juice used in a multi-layer combination. and catsup bottles.
38 Appendix D Recycling codes ENWW E Service and support
To obtain service, please contact the customer care center within your country/region:
Europe:
Belgium: +32 (0)2 626 4803
France: +33 (0)1 57 32 41 07
Germany: +49 (0)69 38 07 89 193
Ireland: +353 (0)1 656 9760
Italy: +39 02 69430637
Luxembourg: +352 (0)24 87 13 98
Netherlands: +31 (0)20 547 6870
Spain: +34 9 12757781
UK: +44 (0)84 5604 7435
APJ:
Japan: +81 (0)1 2085 5536
Singapore: +65 9891 1753
Distribution Channels (DC): +31 (0)20 654 5543
North America: 1-800-204-6344
Israel: +972 (0)8 938 1818
North America and International Israel APJ Latin America
HP HP HP HP
Indigo Division Indigo Division Indigo Division Asia Pacific Pte Ltd
5555 Windward Parkway Startbaan 16 Kiryat Weizmann No.3 Tuas Link 4 #02-01
Alpharetta, GA 30004 1187XR Amstelveen P.O. Box 150 Singapore 637016
USA The Netherlands Rehovot 76101
Israel
ENWW 39 Printing instructions
NOTE: To ensure a high quality print, use the "CAxxx-xxxxx_PRINT.pdf" version of this document.
COVER
Paper weight 250 g
Page size 8.27 x 11.00 in (21 x 27.94 cm)
Printing HP Indigo digital press
Simplex/duplex Front cover - duplex
Rear cover - simplex
Color Full color - high resolution
Coating Lamination - shiny front and rear covers
INSIDE PAGES
Paper weight 80 g
Page size 8.27 x 11.00 in (21 x 27.94 cm)
Printing HP Indigo digital press
Simplex/duplex Duplex
Color Full color - high resolution
Coating None
FINISHING
Stitch 2 saddle stitch on left side
40 Appendix E Service and support ENWW Notes
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______© Copyright 2015 HP Development Company, L.P.
This is an HP Indigo digital print. www.hp.com/go/indigo
PN: CA494-18500