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Home , Acrylate polymer

Luran® S

Acrylonitrile-styrene- (ASA and ASA + PC)

Applications Range Properties Processing Luran S grades offer a broad range of exceptional properties. They feature high thermal stability, good chemical resistance and excellent resist- ance to weathering, ageing and yellow- ing. Therefore, Luran S is used in applications which involve exposure to extreme conditions. Luran S has a broad range of applications...

4 ... in automotive construction 6 ... in electrical engineering and electronics 8 ... in sport and leisure 10 ... in a wide variety of indoor and outdoor uses

Luran S and its characteristic properties

12 The Luran S range at a glance Mechanical properties

15 Resistance to weathering 17 Long-term heat resistance Fire performance Electrical properties

18 Antistatic performance Resistance to chemicals Permeability to water vapour and gases

Processing of Luran S

19 General information

22 Extrusion Blow moulding

23 Machining and post-processing

24 Safety information 25 Luran S and the environment

Supply, literature references

26 Supply Literature references

3 Luran S has a broad range of applications ...... in automotive construction

In the last 15 years, Luran S has captured a large share of the market for exterior automotive parts. More and more users choose Luran S because of its superior properties and its ability to resist UV radiation. Even after long-term weathering, Luran S does not show the greying typical of even UV-stabilized ABS. Also, Luran S withstands hot-water treatments such as the removal of the wax layer from new vehicles and frequent car wash- es. The cost saving compared with coated or painted ABS provides a further incentive for the change to Luran S.

Typical Luran S applications in the auto- motive sector are exterior mirror hous- ings, radiator grills, centre pillar trims, window frames, cowl vent grills, fairings and lamp housings. Even relatively large covering panels are often made from Luran S.

Coloured Luran S is increasingly used instead of metal, coated or painted ABS, or SMC materials for moped, motor scooters and motorcycle fairings. Luran S has also been successfully used for many years in exterior parts of recreational vehicles and trailers.

The commercial vehicle sector is of increasing importance. Draft deflectors, steps, radiator grills and exterior mirror housings from Luran S have so far been developed in joint projects. Dashboards and trim panels made from Luran S have long been in use in agricultural vehicles.

4 5 ... in electrical engineering and electronics

A typical application for Luran S, with its resistance to weathering, is antenna construction. Wind and weather subject the external elements of antennas to severe attack. Unsuitable materials corrode or become brittle. Luran S is not just an all- weather ; it is also the ideal material for heavily used household appliances and long-lived consumer goods, for example “white goods”.

Because of its exceptional UV stability, well-known antenna manufacturers use Luran S for items such as parabolic reflector coverings, mobile antennas, TV antenna parts, cable connection hous- ings, weatherproof protective housings for satellite electronics, diplexer housings and amplifier parts.

Luran S is distinguished by high heat resistance and colour stability combined with excellent resistance to oils, fats and other chemicals – properties which meet the stringent requirements of manu- facturers of washing machine panels, refrigerator handles, mouthwash hous- ings, sewing machines, kitchen appli- ances, grills and microwaves.

For equipment which can experience severe mechanical stresses, for example mobile telephones, the ASA + PC blends are especially suitable.

6 7 ... in sport and leisure

Surfboard or sailboat, golf trolley or skibox - Luran S makes sure that you can enjoy your leisure time. The superior properties of Luran S are seen in improved long-term serviceability. Injection-moulded or extruded, Luran S performs in any weather.

The applications are extensive. They range from surfboards and snowboards to moped and motorcycle fairings.

8 9 ... in a wide variety of indoor and outdoor uses

The combination of properties which gives Luran S its success, namely excellent resis- tance to weathering, ageing and yellowing, have been tried and tested for many years in innumerable applications, both indoors and outdoors.

For example, petrol-powered lawnmowers require good mechanical properties, resis- tance to petrol and colour fastness. This is a clear case for Luran S.

When an outdoor table or a serving trolley has to be scratch-resistant, Luran S not only gives you a surface which is harder than poly- propylene, but also greater rigidity with comparable toughness.

10 11 Luran S and its characteristic properties

The Luran S range at a glance Luran S is the trade name for BASF’s styrene- which are impact-mod- Globally available grades ified with acrylate rubber. The range includes Luran S 757 G: grades for injection moulding and for extrusion. ASA injection moulding grade with high stiffness and flowability Luran S is obtained by copolymerizing styrene and acrylonitrile in combination with an elas- Luran S 776 S: tomeric acrylate-based component. The elas- ASA injection moulding grade with enhanced tomer component is distributed uniformly in the toughness and lower flowability SAN structure in the form of very small parti- Luran S 776 SE: cles. ASA extrusion grade with enhanced toughness; especially suited for sheet and profiles with The Luran S grades which have a “C” at the end reduced gloss of their product name are blends of Luran S 777 K: ASA and (eg. Luran S KR 2866 C). Easy-flowing, ASA injection moulding grade with good impact resistance Luran S 778 T: ASA injection moulding grade with increased heat deflection temperature; especially for automotive parts Mechanical properties Luran S 778 TE: Stress-strain performance ASA extrusion grade with increased heat The mechanical performance of Luran S deflection temperature and high gloss grades is depicted in Fig. 1 using the Luran S 797 S: stress-strain curve from the tensile test. ASA injection moulding grade with very high impact strength Depending on their rubber content the Luran S 797 SE: individual grades show differences in their ASA extrusion grade with very high yield stresses. The shape of the stress- impact strength; especially suited for strain curves also depends on the test sheet and profiles with high gloss temperature and the strain rate. Fig. 2 uses Luran S 778 T to illustrate the tem- Regional products* perature dependence of strength. Luran S 757 R: ASA with high stiffness and medium Increasing test temperatures give higher flowability strain and lower strength values. Luran S 796 M: The modulus of elasticity also decreases ASA injection moulding grade with high with increasing test temperature. How- toughness and enhanced flowability ever, in the temperature range between Luran S KR 2858 G3: –20 and 80°C, relevant in industrial ASA with 15% glass fibres; high stiffness applications, the Luran S grades have a Luran S KR 2861/1C: high and essentially constant rigidity. ASA/PC standard grade for injection moulding and extrusion Luran S KR 2863 C: ASA/PC with very high heat deflection temperature Luran S KR 2864 C: ASA/PC injection moulding grade with high flowability Luran S KR 2866 C: ASA/PC grade with lower PC content; lower heat deflection temperature and impact strength Luran S KR 2867 C WU: Flame retardant ASA/PC with high flowability; free of , bromine and antimony

*not available in all geographic regions

12 60

50 Luran 778 T 40

Stress amplitude (MPa) 30 Luran 797 S

20

10

0 0 2 4 6 8 10 12 Strain (%) Shear modulus The curves for shear modulus and loga- Fig. 1: Stress-strain curve for various Luran S grades (ISO 527 rithmic decrement of mechanical damping tensile test at 23°C) shown in Fig. 3 give insight into the mechanical performance of the Luran S grades when undergoing small, periodically changing deformations, as a 80 -40°C Y function of temperature.

Y -20°C The Luran S grades have a damping maximum at about –40°C which can be ensile Stress (MPa) T 60 attributed to the glass transition tempera- Y 0°C ture of the component. The elastomer component becomes effective Y 23°C above this point and gives Luran S a toughness which increases as the tem- 40 Y 40°C perature rises.

Y 60°C The shear modulus is almost constant Y 80°C over the temperature range from about 20 –40°C to about 100°C. Y 100°C Fig. 2: Stress-strain Thus, Luran S has high rigidity and excel- curve of Luran S lent toughness over a wide temperature 778 T at differing range. 0 0 1 2 3 4 5 temperatures (test Strain (%) was discontinued at 10% strain)

) 2 2 10000 10

Luran S KR 2863 C, G' 1 1000 10

Luran S 778 T, G' 0 100 10 Fig. 3: Shear -1 Shear modules G' (N/mm 10 10 modulus and log- Luran KR 2863 C, tan arithmic decre- Log. damping decrement tan Log. ment of mechani- -2 1 10 cal damping of Luran S 778 T, tan Luran S 778 T and Luran S KR 10-3 -50 -30 -10 10 30 50 70 90 110 130 150 2863 C (ISO 537 Temperature (°C) torsion pendulum test)

13 Impact strength 80 Luran S combines rigidity, strength and dimensional stability with high toughness. Typical values for the impact strength are 60 Luran S KR 2861/1 C given in the brochure “Luran S: Features, typical values, applications”. 40

An assessment of toughness which is Penetration energy (Joule) very well correlated with the performance 20 of in practical applications can be Luran S 757 G obtained using the penetration test according to ISO 6603-2. A bolt impacts 0 -50 -40 -30 -20 -10 0 10 20 30 40 50 the test specimen (usually an injection- moulded disk) at a velocity of about 4.5 Temperature (°C) m/s, and the penetration energy serves as a measure of the toughness. Fig. 4: Penetration energy for 2 mm Fig. 4 shows the penetration energy mea- 25 100 h sured on 2 mm thick disks (diameter 60 thick disks (diam- 1000 h eter 60 mm) 10 h mm) as a function of the temperature. 10000 h While the toughness of Luran S increases of Luran S in the 100000 h with increasing temperature the value for ISO 6603-2 pene- 20 the blends of Luran S with polycarbonate tration test ensile stress (MPa) (Luran S KR 2861/1 C), is almost inde- T pendent of temperature. 15

Creep strength The mechanical performance of 10 Luran S under continuous static load is shown in the isochronous stress-strain curves (Fig. 5-8). The static load which can be withstood is strongly dependent 5 on temperature. The graphs shown here are merely a selection from our extensive Fig. 5: Isochro- test results. nous stress-strain 0 curves for 0 1 2 3 4 5 Luran S 778 T at Strain (%) 23 °C (ISO 899)

10000 h 15 10 h 100 h 100000 h 1000 h ensile stress (MPa) T 10

5

Fig. 6: Isochro- nous stress-strain 0 curves for Luran S 0 2 4 6 8 10 12 778 T at 60 °C Strain (%) (ISO 899)

14 ) 1000 h 10 000 h 2 A very sensitive method of quantifying the 30 100 h change in the mechanical properties of brought about by the effects of 25 weathering is to determine the penetration 50 000 h energy on weathered specimens. If the 20 (unirradiated) reverse side of the speci-

ensile stress (N/mm mens is impacted, the irradiated front side T 15 experiences a sudden tensile stress, so that even the slightest deterioration gives a clear reduction in the measured values. 10 This test is therefore an excellent indicator of weathering resistance. In contrast, if 5 the impact is on the irradiated side, as most frequently happens in practice, a 0 reduction in toughness is only observed 0 0,5 1 1,5 2 2,5 3 3,5 4 after much longer exposure times. Mea- Strain (%) surable reductions in the values of proper- ties such as breaking stress and modulus of elasticity are Fig. 7: Isochronous stress-strain curves for also seen only at a much later Luran S KR 2861/1 C at 23 °C (ISO 899) stage.

) 16 Figure 9 shows the penetra- 2 100 h 1 000 h 10 h tion energy curve for 2 mm 14 thick disks of ABS and Luran S. While the toughness of ABS 12 5 000 h falls away very rapidly, Luran S remains at a high level for a 10 significantly longer period. The ensile stress (N/mm T (ASA+PC)-Blends and UV-sta- 8 bilized Luran S show particu- larly favourable performance. 6

4

2

0 0 0,5 1 1,5 2 2,5 3 3,5 4 Strain (%)

Fig. 8: Isochronous stress-strain curves for Luran S KR 2861/1 C at 80 °C (ISO 899)

70 60 Luran S KR 2861/1 C 50 (PC + ABS) Resistance to weathering 40 30 Luran S 778 T UV Luran S has high resistance to weathering because the elastomer component con- Penetration energy (Joule) 20 sists of an acrylate having a significantly ABS-UV Luran S 778 T higher resistance to UV radiation and 10 attack by atmospheric oxygen than the 0 ABS butadiene rubber which is used, for 0 500 1000 1500 2000 example, in impact-modified Hours of sunshine and ABS.

Fig. 9: Toughness in the ISO 6603-2 penetration test after outdoor weathering in Limburgerhof, Germany; penetration energy on 2 mm thick disks

15 35 30

25 ABS resp. (ABS + PC) 20 15 Luran S (ASA + PC) 10

Degree of yellowing (delta b) Luran S (ASA) 5 Luran S UV 0 -5 0 1000 2000 3000 4000 Hours of sunshine The outdoor weathering of plastics may not only change their mechanical proper- Fig. 10: Yellowing of ABS, Luran S and blends on outdoor weathering ties. The combination of UV radiation, (white pigmentation) atmospheric oxygen and heat frequently causes a clearly visible yellowing. Also in this respect, the chemical structure of 70 Luran S makes it exceptionally stable. 60 Luran S (ASA + PC) Figure 10 shows the yellowing of different 50 white-coloured plastics on outdoor weathering. All products change colour 40 very slightly in the early stages. Whereas 30 Luran S (ASA) ABS and PC + ABS show rapid yellowing Penetration energy (Joule) afterwards, Luran S yellows only at a 20 PC + ABS much later stage and to a much lesser ABS 10 extent. Luran S containing an additional UV stabilizer shows particularly excellent 0 performance. Even after 4000 hours of 0 20 40 60 80 100 sunshine, corresponding to more than Storage time (weeks) two years of outdoor weathering, this product still shows virtually no yellowing. Fig. 11: Toughness of ABS, Luran S and blends after heat ageing at 90°C Penetration energy on 2 mm thick disks The very low level of yellowing of Luran S in outdoor weathering is compa- rable with that of PVC, a material whose 80 ideal suitability for outdoor applications ABS has been proven in many years of use. 60 For applications of Luran S in automotive exteriors it is particularly important that, in contrast to UV-stabilized ABS and PC + Degree of yellowing 40 PBT blends, dark-colored formulations PC + ABS have only a very slight tendency to gray- 20 ing after weathering followed by contact Luran S (ASA) with hot water or soap solution. This rep- resents the typical conditions both for the Luran S (ASA + PC) removal of wax from new vehicles after 00 20 40 60 80 100 120 outdoor storage and also for vehicles Storage time (weeks) which are cleaned after being subjected to solar radiation. Fig. 12: Yellowing of ABS, Luran S and blends (white pigmentation) on heat ageing at 90°C

16 Long-term heat resistance Gaseous combustion products of Electrical properties Luran S The stability of Luran S grades to long- In principle, every combustion process Luran S has good electrical insulation per- term heat exposure can be proven by gives rise to toxic substances; carbon formance. The important parameters are storage at, for example, 90°C. Whereas monoxide is the most important of these the volume resistivity and surface resistivi- the mechanical strength of comparable and generally has a decisive role. ty, the dielectric strength, the comparative ABS products decreases rapidly in this cracking performance, and the dielectric test, Luran S shows only a small change The combustion products of Luran S con- constant and dissipation factor (see the in toughness over the same period (Fig. tain carbon dioxide, carbon monoxide brochure “Luran S: Features, typical val- 11). and water as main components, and also ues, applications”). unburnt carbon (soot), acrylonitrile and Likewise, the resistance to yellowing of hydrogen cyanide as the most important In the electrical supply industry, Luran S on exposure to heat is very much secondary products. Luran S is used particularly for protective higher than that of ABS and PC + ABS insulation-housings and covers. In electri- (see Fig. 12). Toxicological investigations show that the cal communications engineering, Luran S decomposition products formed at up to is used both as a material for housings 400°C are no more toxic than the com- and covers and as an actual insulator. Fire performance bustion gases formed from wood under the same conditions. When decomposi- Fire performance according to UL 94 and tion takes place at above 500°C, the level DIN IEC 707/VDE 0304 Part 3, “Test of risk is comparable with that presented methods for determining the flammability by the combustion of nitrogen-containing under the action of igniting sources” is natural products such as wool and given in the brochure “Luran S: Features, leather. typical values, applications”. The combustion gases from Luran S are Building products made from Luran S are not particularly corrosive. The formation of tested according to “Supplement to DIN soot means that smoke is produced in 4102–Fire performance of building materi- considerable amounts. als and building components”. Flat sam- ples of Luran S of thickness of 1.0 mm and above are generally rated B2 (“build- Flame-retardant Luran S ing materials of normal flammability”) The flame-retardant product Luran S KR according to this standard. Further, they 2867 C WU has been developed for parts are normally rated as “not forming burning subject to higher fire protection require- droplets”. ments. This grade, which contains no chlorine, bromine or antimony, has good For applications in automotive construc- pigmentability, even in pale colours, and tion, the requirements of MVSS 302 excellent resistance to yellowing. The and/or DIN 75200 must be met. Flat product achieves the UL 94 V-0 classifi- specimens of Luran S in thicknesses of cation at a thickness of 1.5 mm and 1mm and above fulfill these requirements. passes the glowing wire test (IEC 695-2-1) at 960°C and a thick- ness of 2 mm.

17 Antistatic performance In pigmented Luran S, the possible effect Permeability to water vapour and of the pigments used must also be taken gases At normal atmospheric humidity levels, into account. For example, certain pig- finished parts made from Luran S have ments can undergo changes in heavily Luran S is impermeable to water. the advantage that dust marks do not chlorinated water, and this can cause a Depending on the pressure drop between form on them during manufacture or stor- colour shift of the parts. the inside and outside, water vapour and age or in use. High electrical charges gases can diffuse through a sheet of applied to the surface of Luran S, for Because such effects vary widely, labora- Luran S. Further details are given in Table 1. example by corona discharge, dissipate tory experiments can only give guidelines; rapidly. it is essential to carry out tests on the The gas permeability also depends on the actual finished part. conditions of manufacture of the films or other finished parts. Resistance to chemicals Detailed information can be found in the data sheet “Chemical Resistance of At room temperature, Luran S is stable to Styrene Copolymers”. saturated hydrocarbons, low-aromatic fuels and mineral oils, vegetable and ani- Luran S has good resistance to stress mal fats and oils, water, aqueous salt cracking; the acrylate rubber in Luran S solutions and dilute acids. Although most gives it a better performance than ABS Luran S grades are also stable to alkalis, (Fig. 13). the polycarbonate content of the Luran S (ASA+PC) grades makes them suscepti- Because of their polycarbonate content, ble to damage by alkalis, ammonia and the (ASA + PC) blends are more suscepti- amines. ble than other Luran S grades to environ- mental stress cracking. Concentrated acids, aromatic hydrocar- bons and chlorinated hydrocarbons, Finished parts made from Luran S do not , ethers and ketones attack require special care. Scratches can be Luran S. treated with the majority of commercially available creams and polishes for , The effect of any medium on a plastic leather or wood. Dirt can be removed article depends to a great extent on the with water and soap or detergents. time of exposure and the temperature. The effect is generally amplified if the Luran S part is subject to internal or external stresses.

It should also be noted that engineering materials usually contain varying amounts of ancillary ingredients, which can have ) 2 different effects on stability. 60 (N/mm

B 50 Luran S (ASA)

40 ABS 30 ensile strength T 20 Medium: isopropanol (1 h) Table 1: Typical values1 for permeability to water vapour and gases 10

2 3 3 0 Luran S-grade Water vapour Oxygen Nitrogen Carbon- 0 100 200 300 400 500 g · m-2 · d-1 cm2 · m-2 ·d-1 · bar-1 dioxide3 797 S 35 550 100 2300 Ball oversize in m

1 The values are highly dependent on the conditions of manufacture of the film, and may vary by more than Fig. 13: Stress cracking performance of Luran S and ABS 50% in either direction as a result. 2 Measured according to DIN 53122, relative humidity drop from 85% to 0%, pressure drop 23.87 mbar. with respect to isopropanol, measured by the ISO 4600 3 Measured by a method similar to that of DIN 53380, Part 2 (M). ball indentation test

18 Processing of Luran S

Luran S can be processed by any The Luran S grades which have a “C” in Because of this we do not recommend of the processes suitable for thermo- their designation (eg. Luran S KR 2861/1 self-colouring of Luran S. Instead we sug- plastics. The most important process- C) are blends of ASA and polycarbonate. gest using Luran S coloured by BASF. es are injection moulding and extru- Since these products are generally sion. Because of its chemical struc- processed at melt temperatures which are Over several decades BASF has devel- ture, Luran S is relatively stable to the higher than those for other products in oped considerable expertise in the temperatures encountered in pro- the Luran S range, we always recom- colouration of Luran S. The colourants cessing. Even so, unnecessarily long mend that they be predried. The drying used meet high requirements and have residence times in the machine temperature should be about 10–20°C passed stringent tests in order to be should be avoided, especially if melt lower than the Vicat softening point approved for Luran S. Therefore Luran S temperature is high. (VST/B/50, see “Luran S: Features, typical coloured by BASF has excellent weather- values, applications”). The drying condi- ability and heat ageing resistance, and the tions are given in Table 2. colourants are embedded permanently in the plastic material.

Mechanical Recycling Because of its high thermal stability, up to 30% of clean Luran S of a single grade and whose previous processing has not involved contamination may be added to the starting material in the manufacture of moldings where this is appropriate. The usual crushers or granulators can be used for size reduction. Regrind should be well dried.

General information Self-colouring of Luran S Special know-how is required for colour- Predrying ing Luran S. Compared to other plastics, Luran S granules can absorb small e.g. ABS, Luran S requires much higher amounts of moisture from the air during pigment concentrations. Many colourants storage. Although this does not change and masterbatches are unsuitable due to the properties of the product, streaks or their insufficient heat or weathering resis- bubbles can appear during processing, tance. In addition, unsuitable colourants depending on the moisture content. We or masterbatch ingredients may, over therefore recommend predrying of Luran S time, migrate to the surface of the finished before processing. parts or be extracted by the influence of chemicals (e.g. cleaning agents or sol- vents).

Table 2: Drying temperature Drying time Acceptable (°C) (h) moisture content Luran S (ASA) 80 2–4 < 0.1 Luran S (ASA+PC) 90–115* 2–4 < 0.1 * = 10–20°C below Vicat softening point VST/B/50

Table 3: Typical values for screw configuration Zone length Flight depth in mm

Overall length L 16-20 D D* hE hA Feed zone LE 0.5 L 30 5 2.5 Compression zone LK 0.3 L 50 6 3 Metering zone LA 0.2 L 70 8 4 D*= Screw diameter hE= Flight depth in the feed zone hA= Flight depth in theMetering zone

19 Nozzles Injection mould Open nozzles can be used for process- Gate and mould design ing Luran S moulding compounds be- Any known type of gate may be used, cause Luran S melts are relatively vis- including hot runner systems. cous. Open nozzles have a very simple design and therefore give particularly The guidelines for the design of gates and good flow. moulds for the manufacture of injection- moulded parts from (VDI Shut-off nozzles have advantages when 2006) are also applicable to Luran S. high back pressure is being used or Gates and feed channels should not be undesirable stringing has to be avoided too small, otherwise excessively high melt and thick-walled parts are to be manu- temperature and injection pressure are factured. required. This can result in streaks, char- ring caused by shear, voids or sink marks. Mechanically or hydraulically operated needle valve nozzles have proven the Use of inserts most successful. Metal parts can be moulded in without An eventual warpage of the moldings can difficulty, but they should be preheated to be counteracted by separate and differen- 80–120°C before being placed in the tiated temperature control of the two mould so that no internal stresses are halves of the mold. created. The metal parts must be free of grease, and to improve anchoring should The injection moulding process have milled, grooved or similar Processing temperature surfaces. Metal edges should Luran S moulding compounds are be well rounded. generally processed at melt temperatures of from 240 to 280°C, but the poly- Mould temperature control carbonate-containing Luran S grades A carefully designed tempera- (eg. Luran S KR 2861/1 C) should be ture control system for the processed at 260 to 300°C except the mould is particularly important, flame-retardant grade Luran S KR 2867 since the effective mould sur- CWU, for which a temperature range of face temperature has a deci- 260 to 280°C is recommended (Table 4). sive effect on surface quality (gloss, flow lines) and on the For processing at the upper end of the weld line strength, distortion, temperature range short residence times shrinkage and tolerances of should be used, since otherwise the mouldings. The recommended mould sur- material can undergo thermal degrada- face temperatures for Luran S grades are tion. This can be recognized in coloured given in Table 4. compounds by the change in colour; it normally becomes somewhat paler.

Table 4 Processing Mold Typical temperature (°C) temperature (°C) shrinkage (%) Luran S (ASA) 240-280°C 40-80°C 0.4-0.7 Luran S (ASA+PC) 260-300°C 60-90 °C 0.3-0.7 Luran S KR 2867 C WU 260-280°C 40-60°C 0.3-0.7

20 Feed characteristics Flow characteristics Even at high screw rotation rates plastifi- The spiral flow test in Figs. 14 and 15 cation of Luran S moulding compounds shows the flow characteristics of proceeds smoothly and without thermal Luran S. Although this test is not covered degradation. Plastification performance by a standard, it gives an assessment rises with increasing processing tempera- which is close to practical experience. ture. The flowability or the flow distance of a It is frequently possible to set the individ- product depends not only on the pro- ual heating zones of the cylinder to the cessing parameters, such as injection same temperature. For high processing pressure, injection rate, melt temperature temperatures and/or for long cycle times and mould temperature, but also on the the temperature of the first heater band design of the mould. (close to the feed hopper) should be set somewhat lower in order to prevent pre- mature melting of the granules in the feed zone (bridging).

Mould filling A relatively high injection speed is useful since little cooling occurs during mould filling; this gives a glossy surface, a low 800 visibility of the weld lines and a high weld 757 G line strength. Too low a rate of mould fill- 700 ing gives parts with unsatisfactory sur- faces. 777 K Flow distance (mm) 600 When the melt is injected, care should be taken that the air in the mould cavity can 796 M escape at a suitable point, to avoid char- 500 ring by compressed air (Diesel effect). 797 S

To obtain perfect injection-moulded parts 400 778 T Fig. 14: Flowability of and to prevent the formation of voids, the Luran S (ASA) as a function hold pressure and the hold pressure time of melt temperature must be sufficient to compensate the vol- 300 (spiral flow test). ume reduction which occurs when the Mould: Test spiral melt is cooled. On the other hand over- 2 mm x 10 mm; feeding of the mould cavity must also be 200 Injection pressure: avoided, since this causes stresses in the 240 260 280 1100 bar; moulding. The risk of overfeeding exists Melt temperature (°C) Mould surface temperature: mainly in the vicinity of the gate, at high 60 °C injection rates and high hold pressure. 600

500

Spiral flow distance (mm) KR 2864 C 400 KR 2863 C Fig. 15: Flowability of Luran S (ASA + PC) as a function of melt temperature 300 (spiral flow test). KR 2861/1 C Mould: Test spiral 2 mm x 10 mm; Injection pressure: 200 260 270 280 290 300 1100 bar; Melt temperature (°C) Mould surface temperature: 80 °C

21 Mould release Extrusion Blow moulding Luran S can be readily demoulded, so that even mouldings of complicated Luran S is highly suitable for the extrusion The Luran S grades most suitable for design are possible. Drafts of from 0.5 to of sheets, solid and hollow profiles and blow moulding are those with low flowa- 0.9° are generally sufficient. pipes. Specific extrusion grades are avail- bility. able for this and are identified with an “E” Textured surfaces require larger drafts: 1° (eg. Luran S 797 SE). The parison should be extruded at a melt makes it possible temperature of from 220 to 230°C. In to demould a part individual cases, the melt temperature can with 0.02 mm Sheet be lowered to about 210°C in order to depth of texture manufacture reduce stretching of the extruded tube. from the mould Suitable extru- cavity and a part ders for the man- In order to avoid a high material tempera- with 0.01 mm ufacture of ture resulting from frictional heat, the from the mould extruded sheets screw of extruders with a grooved, cooled core. comprise those and thermally insulated feed zone should generally used for have somewhat deeper flights than those, Shrinkage and processing for example, for high-molecular-weight post-shrinkage impact-modified PE-HD. Shrinkage is sig- polystyrene and nificantly lower ABS, having a Short ejection cycles, as achieved when with Luran S sheet extrusion melt accumulators are used, are advanta- moulding compounds than with semi- die. Vented extruders with a screw length geous. crystalline plastics. of from 25 to 30 D and a compression ratio of from 1:2 to 1:4 are preferable. Undercuts in blowing moulds, eg. at the The processing shrinkage is usually from thread runout or as a result of the curva- 0.4 to 0.7%, and in exceptional cases In most cases the optimum throughput ture of bottle bases, should be avoided. well below 0.4%. In regions of a mould- of sheets with superior mechanical The pinch-off areas can be designed in ing which experience high hold pressure properties and good appearance is the same way as for PE-HD processing. (near to the gate) it may even be close to achieved at about 230°C for the Luran S The pinch-off edges should be as sharp 0%. (ASA) grades or at about 260°C for the as possible to ease flash removal. In the Luran S (ASA + PC) grades. case of engineering parts, the flash areas Post-shrinkage is negligible in most appli- should be sectioned off by well-defined cations, making up about 1/10 of the pinch-offs. overall shrinkage. Pipe and profile manufacture The same conditions apply for the manu- facture of pipes and profiles as for the extrusion of sheets. The melt tempera- ture, however, is generally set lower in order to achieve sufficient melt strength between die and calibrator. The recom- mended lower limit here is 200°C. Prefer- ably, the cooling conditions should be set to give an external temperature of about 70 to 80°C for the semifinished products after passing through the waterbath.

22 Thermoforming Under standard conditions of temperature Ultrasonic welding can also be used to and pressure, the final moisture absorp- connect Luran S to a number of other Sheets and films made from Luran S can tion value is about 0.4%, and it is thermoplastics, such as SAN, ABS, PVC be thermoformed to give mouldings with achieved after about 20 days in the case and PMMA. good wall thickness distribution. Thermo- of 1.5 mm thick sheets. Even a moisture forming of Luran S can be carried out content of from 0.05 to 0.1% can, how- bonding with standard machinery for the vacuum ever, impair the surface of mouldings. Examples of solvents suitable for adhesive forming and compressed-air forming of Wrapping in welded film of bonding are methyl ethyl ketone, dichloro- sheets and films. Recommended forming adequate thickness, ie. at least 100 µm, ethylene and cyclohexanone. Parts made temperatures are from 140 to 170°C. provides effective protection against the from different grades of Luran S may be absorption of moisture. This special pack- bonded to one another, and furthermore ing greatly delays the absorption of mois- parts made from Luran S may be bond- Storage and packing of thermo- ture, but does not prevent it entirely. Even ed to parts made from ABS or SAN. forming sheet specially packed Luran S sheets should Like ABS, Luran S tends to absorb mois- therefore be stored under dry conditions. For more information we recommend ture under poor conditions of storage. contacting the industry, which On thermoforming, sheets which have offers a wide variety of suitable special become moist can generate bubbles Machining and post-processing adhesives. which make the moulding unusable. Machining Storage in dry areas (about 20°C, 30% Semifinished products made from Luran S Surface treatment relative humidity) prevents the absorption are easy to machine, ie. die-punch, saw, Parts made from Luran S may be easily of moisture which impairs thermoforming. drill, mill, turn etc., using conventional and permanently printed, coated or paint- However, if storage takes place under metal- and woodworking machinery. ed without any special pretreatment. They standard conditions of temperature and can also be metallized by the metallizing pressure (DIN 50014-23/50-2), the mois- Tools used for machining brass and processes commonly used in industry. ture content may reach levels which could bronze are suitable. Because heat dissi- adversely affect processing after some pation is slow, water cooling is frequently days or weeks. necessary even at low cutting speeds. Luran S parts can be stamped and flanged without difficulty and can be fas- tened using self-tapping screws.

Assembly Welding Hot-plate and spin welding are suitable for welding semifinished products and mouldings made from Luran S, and in specific cases high-frequency and ultra- sonic welding can also be used.

23 Safety information No substances which can damage the ozone layer (ODC) of Class I (CFC/Halons) Safety precautions during or Class II (HCFC) are used as starting processing materials or additives in the manufacture No adverse effects on the health of Luran S. of processing personnel have been observed when process- For coloured materials the Rec- ing of the products is carried ommendation IX “Colorants for Luran S in the medical sector out correctly and there is pigmentation of plastics and other BASF does not carry out product devel- suitable ventilation of the polymers for consumer goods” of the opments for applications in medical prod- production areas. The German Federal Health Office should ucts (including packaging) as defined by maximum allowable con- be taken into account. the German Medical Product Act. We centrations (MAC) of 20 therefore have no in-house experience of ml/m3 for styrene, 100 The suitability of consumer goods in any the suitability of Luran S in applications of ml/m3 for -methyl- particular instance should be tested by this type and, as a result, BASF is unable styrene, 10 ml/m3 for butyl the manufacturer or by the user with ref- to make any product recommendations acrylate and the technical erence to the maximum permissible for this section. reference concentration migration values which are established of 3 ml/m3 for acrylonitrile by law: must be observed (German Hazardous Materials Regulations Acrylonitrile: SML = not detectable 900; MAC list 1999). Acrylonitrile is a (detection limit = 0.02 mg/kg) Group III, A2 substance for which car- : SML = 3 mg/kg cinogenic activity is assumed as a result Phosgene: QM = 1 mg/kg of toxicity testing. Experience has shown that when Luran S is processed correctly (SML = specific migration limit in foods or with appropriate ventilation, the levels are food simulants; QM = maximum allowable far below the limits mentioned above. residual content of the substance in the Inhalation of the vapours of degradation consumer good) products which can arise on severe over- heating of the materials or during pump- In cases where Luran S is to be used in ing out should be avoided. Our safety contact with foodstuffs, we will be happy data sheets give further information. to provide more detailed information and confirmation regarding compliance with regulatory requirements. Food regulations Most Luran S formulations fulfill the requirements of the German Consumer Goods Regulations of 23.12.97 and of Recommendation VI “Styrene polymers, copolymers and graft polymers” and Recommendation XI “” of the German Federal Health Office as at 01.06.98.

24 Luran S and the environment

Waste disposal In Germany, Luran S waste is classified under Waste Code No. 57108 (poly- styrene wastes), except for the Luran S (ASA + PC) grades, which contain poly- carbonate and are classified under Waste Code 57117.

Under German waste monitoring regula- tions, solidified plastic waste of this type does not require any special disposal measures. Luran S waste can therefore usually be disposed of to landfill (cf. Safe- ty Data Sheet). According to our knowl- edge, Luran S waste is inert in landfill. Luran S is classified as presenting no threat to ground water. Recovery Subject to official regulations Luran S may Waste consisting solely of Luran S can be also be incinerated in a suitable incinera- recycled. Waste arising during injection tor, eg. a household waste incinerator. moulding or thermoforming, for example, The fuel value of Luran S is about 10 can be fed back to the process as regrind kWh/kg, about 70% higher than that of (cf. mechanical Recycling, page 19). Used dry wood. Complete combustion gives parts consisting solely of Luran S can also carbon dioxide, water and nitrogen, the be recycled, after cleaning and size nitrogen being oxidized to a limited extent reduction, to give new mouldings. to give nitrogen oxides. Depending on the age and application of the used parts to be mechanically recy- cled, certain properties, such as mechani- cal properties, colour etc., may have undergone change; it is therefore neces- sary to check the suitability of the recy- cled material for the intended application in each individual case.

The good compatibility of Luran S with ABS also makes it possible to include a limited quantity of Luran S in the process- ing of ABS (up to about 25% of Luran S, based on ABS).

It should be noted that, under Underwrit- ers Laboratories (UL) regulations, the flame-retardant grade Luran S KR 2867 C WU does not retain its UL material classi- fication when more than 25% of regrind or recycled material is added.

25 Supply and literature references

Supply Literature references

Product quality alone is no longer any BASF publications guarantee of success in the market. We “Chemical Resistance of Styrene offer our customers tailored supply Copolymers” arrangements so that they can achieve (TI-KTC/A 01 d 82 442 July 1995) success in the marketing of their prod- ucts. Our professional advice and cus- “BASF Plastics: Automotive construction” tomer care ensure that service and costs B 569 are kept in balance, from recognizing customer requirements at order place- “BASF Plastics: Electrical engineering” ment, production, storage and distribu- B 570 tion through the receipt and use of our products. We can help in finding the right methods for reducing raw materials Other literature inventory or achieving service level tar- Besides advising on measures to “Design of injection mold- gets. Special measures can often be increase the security of supply over the ings” VDI 2006 found to make shipments quicker and entire supply chain, our specialists can more flexible. We will help you optimize also help with packing, transport and G. Lindenschmidt, R. Theysohn: “Styrene cost-value ratios. storage problems. We can collaborate as copolymers (SAN, ABS, ASA)” partners to offer help and solutions on Kunststoffe, 77 (1987), p. 982 When the customer examines the whole any question which may arise. of the supply chain, certain questions K. Ruppmich: “ASA/PC - An interesting always arise: In which situations does Cooperation from order booking to deliv- alternative to ABS/PC” fast and flexible delivery really make ery brings the supplier and customer Kunststoffe, 75 (1985), p. 740 advantages which are well worth having. B. Rosenau: “ASA plastics: Properties and applications” Kunststoffe, 85 (1995), p. 804

A. Zahn: “ASA and ABS compared” Kunststoffe, 87 (1997), p. 314

BASF Diskettes Campus

Download: http://www.basf.de/en/produkte/kstoffe/ kstoffe/werkst/campus.htm

Internet: http://www.basf.de sense? What are the consequences for costs in the overall supply chain? What is an acceptable level for raw material inventory costs? What degree of delivery reliability is necessary to allow a continu- ing reduction in inventories?

26 Plastics from BASF The product range at a glance

Products from BASF Aktiengesellschaft Further Information: Terluran® Acrylonitrile/butadiene/styrene polymer ABS www.basf.com Ronfalin® Acrylonitrile/butadiene/styrene polymer ABS www.basf.de Luran® S Acrylonitrile/styrene/acrylate polymer ASA, (ASA + PC) Additional information Luran® Styrene/acrylonitrile copolymer SAN

® Terlux /acrylonitrile/butadiene/ MABS on can be styrene polymer found at: Terblend® N Acrylonitrile/butadiene/styrene polymer and ABS + PA www.elastogran.de Luranyl® Blend of polyphenylene ether and PS-I (PPE + PS-I) Polystyrol, impact-modified Styrene/butadiene polymer PS-I on polyolefines can be Polystyrol, impact modified Polystyrene PS found at: Styrolux® Styrene/butadiene block copolymer SBS www.basell.com Styroblend® Blend based on styrene/butadiene polymer PS-I blend on PVC and PVDC can Styroflex® Styrene/butadiene block copolymer SBS be found at: ® Ecoflex / www.solvay.com and Ultradur® terephthalate PBT, (PBT + ASA) www.solvay.de Ultraform® POM Ultramid® PA 6, 66, 6/66, 6/6T Ultrason® E Polyethersulfone PES Ultrason® S PSU Styropor® Expandable polystyrene EPS Neopor® Expandable polystyrene EPS Styrodur® C Extruded rigid polystyrene foam XPS Neopolen® P foam EPP Neopolen® E Polyethylene foam EPE Basotect® Foam from melamine resin MF Palusol® Silicate foam ® = reg. trademark of BASF Aktiengesellschaft Polyurethanes Lupranat® Diisocyanates PU Lupraphen® Polyester polyols PU Lupranol® Polyether polyols PU Pluracol®* Polyether polyols PU Elastan® Systems for sportsfield coverings PU Elastocoat® C systems as coating and casting compounds PU Elastoflex® Soft foam systems PU Elastofoam® Soft integral polyurethane foam systems PU Elastolit® Rigid integral polyurethane foam systems PU and RIM systems Elastonat® Flexible integral polyurethane systems PU Elastopan® Polyurethane shoe foam systems PU Elastopor® Rigid polyurethane foam systems PU Elasturan® Systems as cold curing cast PU Note SPS® Steel-polyurethane systems PU The information submitted in this publication is based on our current knowl- Elastospray PU system PU edge and experience. In view of the many ® Autofroth PU system PU factors that may affect processing and ElastoskinTM* Flexible integral polyurethane systems PU application, this data does not relieve Cellasto® Components made from microcellular PUR elastomers PU processors of the responsibility of carrying Elastocell® Components made from microcellular PUR elastomers PU out their own tests and experiments; CeoDS® Multifunctional composits made from Cellasto® components PU neither do they imply any legally binding assurance of certain properties or of Emdicell® Components made from microcellular PUR elastomers PU suitability for a specific purpose. It is the ® Elastollan Thermoplastic polyurethane elastomers TPU responsibility of those to whom we supply ® = reg. trademark of Elastogran GmbH ® resp. TM = reg. trademark of BASF Corporation our products to ensure that any propri- * * etary rights and existing laws and legisla- tion are observed.

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