ABS — Acrylonitrile Butadiene Styrene
Acrylonitrile Butadiene Styrene
ABS is an amorphous styrenic thermoplastic prized for its balance of rigidity and impact resistance and its excellent surface finish. It is the go-to material for aesthetic technical parts in injection molding (housings, fascias, trims).
- Mold temperature: 40-80°C
- Melt temperature: 220-260°C
- Shrinkage: 0.4-0.7%
- Density: 1.04-1.07
- Manufacturer grades: Terluran GP-35 (INEOS Styrolution), Cycolac MG47 (SABIC), Novodur P2MC (INEOS)
Processing
ABS is hygroscopic: drying for 2 to 4 h at 80 °C before molding is recommended, otherwise residual moisture causes silver streaks and a drop in impact strength. Use a rising temperature profile from 220 to 250 °C, moderate back pressure to homogenize without over-shearing, and a mold regulated between 50 and 60 °C for good surface gloss.
Advantages
- Excellent surface finish, chrome-platable and paintable
- Good dimensional stability (amorphous, low shrinkage)
- Easy to machine, bond and assemble
- Good rigidity-to-impact-resistance ratio
Limitations
- UV-sensitive: yellows outdoors (prefer ASA)
- Limited chemical resistance to solvents and hydrocarbons
- Moderate continuous service temperature (≤ 80 °C)
- Flammable without flame-retardant additive
Common injection molding defects
- Silver streaks — Residual moisture: dry ABS before molding
- Weld lines — Very visible on dark colors: raise melt temperature and speed
- Sink marks — On thick sections: increase holding and review rib design
Typical applications
Electronic housings, automotive dashboards, toys, home appliances