ABS Advanced Engineering & Material Science FAQ

• Polycarbonate/ABS: This is the most common alloy. It combines the high impact resistance and heat resistance of PC with the excellent processability and toughness of ABS.
• Polyamide/ABS: Nylon 6 is alloyed with ABS. This combination offers significantly higher chemical resistance, increased mechanical strength, and better fatigue resistance.

The most common ABS blends include polybutylene terephthalate/ABS with enhanced chemical resistance, polyvinyl chloride/ABS that offer excellent fire-retardant properties, and polymethyl methacrylate/ABS that offer high scratch resistance. See full details of the different ABS blends here.

PC/ABS blends have higher melt flow rates, which makes it easier to use for molding complex, thin-walled parts and reducing manufacturing cycle times. The blend also has higher heat resistance, with heat deflection temperatures exceeding 100°C. PC/ABS blend delivers exceptional surface finish, rigidity, and stability, reducing warping in finished parts.

PC/ABS is highly hygroscopic, which means it absorbs moisture from the air. If the moisture content is not reduced below 0.04% (ideally 0.02%), it can lead to surface defects and brittle parts after molding. To achieve the desired moisture content, dry it for 2-4 hours at 90°C to 110°C.

ABS is combustible and produces harmful fumes when it burns, including toxic styrene, carbon monoxide, and hydrogen cyanide. It is not biodegradable, which makes it a contributor to environmental pollution.

Although ABS already has good impact resistance, the addition of different agents can help to overcome its inherent limitations as follows:

• Rubber modifiers: Polybutadiene, ethylene-propylene-diene monomer (EPDM), and other elastomeric compounds are used to absorb impact energy, stop crack growth, and reduce stress concentration.
• Epoxidized styrene-butadiene-styrene (SBS): It is used to toughen recycled or waste ABS, significantly boosting notched Izod impact strength by up to 59% in some cases.
• Thermoplastic elastomers: They are blended with ABS to improve toughness and flexibility. Examples include TPO, POE, and SEBS.
• ABS graft powder: Acts as a toughening agent in flame-retardant ABS.

PC/ABS and ABS/PVC are high-performance engineering thermoplastics that combine the toughness and strength of the individual components. Below are a few examples of how they are applied across different industries, but you will find more detailed examples here.

• Automotive industry: Used for interiors (e.g., dashboards, instrument panels) and exteriors (e.g., fender panels, radiator grilles).
• Electronics and communication equipment: Suitable for office or computer components (e.g., keyboard housings, mice), and consumer electronics (e.g., TV rear housing).
• Household appliances: large appliances (e.g., vacuum cleaner shells) and kitchenware (e.g., blender casings).

Modifications can be in the form of blending, additive, surface modification, or reinforcement.

• Blending with other polymers: The heat resistance of ABS can be improved by combining with PC, while chemical resistance can be improved with PA.
• Additive: flame retardants, thermal stabilizers, and anti-static agents enhance material safety and performance.
• Surface modifications: Roughening the surface helps to improve paint adhesion and electroplating quality.

Reinforcement: The addition of 20-40% glass fiber significantly improves tensile strength, dimensional stability, and flexural modulus, but lowers impact strength.

The different modifications are achieved either by altering the ratios of the 3-base monomer, introducing additives, or alloying with other plastics.

ABS still tends to warp during cooling, even when modified. This is particularly true for large or complex 3D-printed or molded parts.

Compliance tests for ABS make sure the material meets specific safety, environmental, and performance standards required for the intended real-world application.

It is commonly used for kitchen appliances, refrigerator components, and food packaging. It doesn’t contain carcinogens and is considered safe for contact with food. Worthy of note is that only specialized “food grade” ABS that has undergone certification to ensure no harmful substances are released should be used for direct, prolonged food contact.

Although safe at room temperatures and generally considered non-toxic in its solid form, ABS can release harmful, pungent fumes if heated to high temperatures, for example, during 3D printing.

On the other hand, specialized flame-retardant ABS is engineered to meet stricter standards, especially UL 94 V-0, which requires the material to self-extinguish within ten seconds after being ignited without producing flaming drips.

Acetone test: When you apply a small drop of acetone to an ABS, the area becomes soft and sticky, and will dissolve over time.

Burn test: It burns with a yellow flame (often with blue edges) and produces dense black smoke. The smell emitted has a faint, sweet, or rubbery smell.

Density test: When you place a small sample of ABS in water, it will sink because it has a density between 1.05 and 1.18 g/cm³.

Physical traits: ABS has a high-gloss, opaque appearance, is rigid, and brittle. It often exhibits whitening at a bend or break point.