Moisture absorption is low, permitting molded parts to serve reliably in environments involving humidity changes. A new acetal copolymer resin, Ultraform S 1320X-003, is available from BASF Corporation Plastic Materials. The impact-modified acetal copolymer resins have a good balance of toughness and rigidity, with modulus of elasticity as high as 305,000 psi. Acetal copolymers have excellent resistance to chemicals and solvents. Continuous contact is not recommended with strong oxidizing agents such as aqueous solutions containing high concentrations of hypochlorite ions.
Most organic reagents tested have no effect, nor do mineral oil, motor oil, or brake fluids.
Samples tested in boiling water retain nearly original tensile strength after nine months. Plumbing products such as valves, valve stems, pumps, faucets, and impellers utilize the lubricity and corrosion and hot-water resistance of the copolymer. Mechanical components that require dimensional stability, such as watch gears, conveyor links, aerosols, and mechanical pen and pencil parts, are other uses. Applications for the FDA-approved grades include milk pumps, coffee spigots, filter housings, and food conveyors.