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Resin Data
ABS

Acrilonitrilo Butadieno Estireno

ABS·Polystyrenes·Amorphous

ABS (Acrylonitrile-Butadiene-Styrene) is probably the most widely used resin in injection molding — and for good reason. It combines rigidity, impact resistance and a good surface finish at a reasonable cost, making it the default choice for electronics housings, toys, automotive parts, appliances and thousands of everyday products.

But behind that simplicity there are nuances that make the difference between a clean run and a lost day from flash, silver streaks or warped parts. Here we have compiled the reference ranges from the PDS, plus the questions that come up over and over on the shop floor: how to dry it correctly, how much regrind it tolerates, when to switch to PC or HIPS, and what to do when silver streaking shows up.

Share your experience in the comments — ranges vary by manufacturer and additives, and collective discussion is what gets us out of trouble on the floor.

The ranges shown in these data tables were compiled by the MVPS team from various parameter sheets and literature, integrating the lower and upper limits for each material type.

This information must be carefully reviewed when developing injection molding processes. Final ranges and processing tolerances are the responsibility of the engineer in charge.

These ranges are not recommended for developing specific process tolerances. MVPS always recommends requesting and consulting the supplier's data sheet.

General Properties

Chemical StructureAmorphous
Specific Gravity (Density)0.91:1
L/D Ratio15 – 22:1
Compression Ratio1.5 – 3:1
Tonnage Factor3.86 – 5.41kN/cm²
Thermal Diffusivity0.1691mm²/s
Max Shear Rate50,0001/s
Shrinkage0.7 – 1.6%
Regrind30%
Heat Deflection (HDT) @ 1.82 MPa88°C
Glass Transition (Tg) @ 10°C/min99°C
Vicat Softening @ 50N95°C

Drying

Drying Temperature77 – 88°C
Drying Time2 – 3h
Recommended Moisture0.1%
Recommended Dryer TypeDesiccant
Dew Point-40°C

Temperatures

Melt241 – 271°C
Nozzle210 – 252°C
Front221 – 260°C
Middle210 – 252°C
Rear204 – 241°C
Demolding66 – 91°C
Mold (Cooling)49 – 79°C
Feed Throat35 – 79°C

Processing

Back Pressure3.4 – 14.8bar
Screw Speed30 – 70RPM
Injection SpeedMedium – High
Barrel Occupancy20 – 85%
Injection Pressure500 – 1,400Pbar
Holding Pressure125 – 1,120Pbar
Cushion3.2 – 6.4mm

Mold

Runner Diameter3.05 – 6.1mm
Gate Diameter0.76 – 1.52mm
Gate Area0.46 – 1.82mm²
Wall Thickness1.19 – 4.06mm

Venting

Depth (Vent Depth)0.0254 – 0.0508mm
Land (Vent Land)0.508 – 1.02mm
Width (Vent / Clearance)3.05 – 12.7mm
Relief (Relief Channel)0.127 – 0.254mm

Frequently asked questions

ABS is an amorphous terpolymer made of three monomers: Acrylonitrile (provides chemical resistance and thermal stability), Butadiene (improves toughness and impact resistance) and Styrene (contributes rigidity and good surface finish). The ratio of each defines final behavior: more butadiene → more impact but less stiffness; more styrene → better gloss but more brittleness.
Grades specifically formulated and certified by FDA or EFSA are suitable for food contact, but not every ABS can be assumed to be. Safety depends on additives, colorants and processing method. Some grades may contain traces of BPA. Recycled or mixed material is never assumed food-grade. If you need food contact, ask the supplier for the specific lot certificate.
Yes, ABS is a 100% recyclable thermoplastic. It tolerates between 5 and 7 reprocessing cycles before significant degradation, and blending with virgin material extends its useful life. The PDS recommends using up to 20% regrind while maintaining virgin-equivalent properties. In the international recycling code it is #7 (other), so not all municipal programs accept it separately.
PC beats ABS in impact resistance (especially at low temperature), thermal tolerance and optical transparency. ABS beats PC in ease of processing, chemical resistance and cost. The PC/ABS blend takes the best of both. Rule of thumb: if you need transparency or extreme impact, PC; if you want a balanced economical mix of properties, ABS; if you want both, PC/ABS.
ABS is hygroscopic — it absorbs moisture from the environment. If you inject with moisture above 0.05%, the steam generates silver streaks, bubbles and cloud-like patterns on the surface. The PDS recommends desiccant drying at 79–93°C for 2–4 h until reaching 0.05% or less.
Flash most commonly comes from three sources: (1) excessive injection or holding pressure, (2) insufficient clamping force for the projected area, (3) wear on the mold parting surfaces. Solution: lower pressure to the point where the part still fills completely, verify your tonnage calculation, and inspect the mold periodically.
The PDS marks 20% as the recommended maximum while maintaining virgin-equivalent properties. Above that, expect progressive impact loss and possible yellowing. For critical parts (medical, structural automotive) many OEMs forbid regrind. For cosmetic or non-structural parts you can go higher, but validate with your customer.
HIPS is cheaper and easier to process but has worse surface finish, lower dimensional stability and lower impact resistance. ABS is the choice when you need good cosmetic appearance, better dimensional stability and higher toughness. HIPS wins for economical packaging, internal non-visible parts and applications where cost rules.
Prolonged UV exposure degrades the butadiene phase, oxidizing it. Result: yellowing, loss of gloss, surface brittleness. For outdoor use there are ABS grades with UV stabilizers, or it is better to switch to ASA (acrylonitrile-styrene-acrylate), formulated specifically to resist weathering without losing ABS's processing advantages.
The PDS marks 41–80°C for the mold with 54–82°C for demolding. Hotter = better surface gloss and lower residual stress but longer cycle. Cooler = shorter cycle but risk of stress cracking and worse finish. For cosmetic parts aim for 70–80°C; for functional technical parts 50–60°C usually gives a good balance.

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