Choosing the Right Polymer: ABS, PP, PC, Nylon and SAN in Household Appliances

Material decides more than cost

In a small appliance, the polymer choice sets the part’s stiffness, impact resistance, heat tolerance, chemical resistance, appearance, food-contact suitability and processing behaviour. Getting it right at the design stage avoids redesigns after tooling, when changes are expensive.

The materials below account for the majority of moulded components in the categories we manufacture.

ABS for the exterior

ABS is the default for visible housings. It moulds with a high-gloss or textured finish, takes colour well, resists impact and can be painted or printed. Its weaknesses are UV yellowing and limited chemical resistance, which is why it is rarely used for food-contact or wet-zone parts.

For iron bodies and hot-zone housings, heat-resistant ABS grades or ABS/PC blends provide extra margin against distortion.

PP for jars, lids and wet zones

Polypropylene is tough, chemically inert and available in food-contact grades. It resists the acids, oils and detergents of a kitchen, tolerates repeated washing and can be moulded with living hinges. Its lower stiffness and tendency to shrink more than ABS must be allowed for in tooling.

Homopolymer PP is stiffer; copolymer PP is tougher at low temperatures. Jars and bases usually use the former, snap-fit lids and hinged parts the latter.

PC and SAN for transparency

Where the user needs to see the contents—blender jars, kettle windows, food-processor bowls—polycarbonate offers exceptional impact resistance and heat tolerance. SAN is a lower-cost transparent alternative for parts that are not subject to impact or heat, such as measuring cups and dry-ingredient containers.

Nylon and acetal for the drivetrain

Gears, couplers and bushings need strength, wear resistance and low friction. Glass-filled nylon provides structural strength; acetal (POM) provides low friction and dimensional stability. Both require careful drying and tooling that accounts for their shrinkage.

• Jar couplers and drive gears: glass-filled PA or POM
• Sliding switches and latches: POM
• Load-bearing internal frames: PA-GF or PP-GF

Selection in practice

Selection is a joint decision between product engineering and the moulding team. The engineer defines the functional and safety requirements; the moulder brings the processing knowledge—shrinkage, flow length, drying needs, colour behaviour. In an integrated factory that conversation happens in one meeting, and the material certificate, the dryer setting and the parameter sheet all reflect the same decision.