Polymethyl methacrylate (PMMA) is a smooth, glossy, hard, and dense material, ranging in color from pale yellow to white, with thin-walled sections appearing semi-transparent. It has flammable properties, continuing to burn after being removed from the flame, with a yellow flame tip and a blue flame base, melting and dripping, emitting a strong刺激性甲醛 odor and fishy smell. Acetal resins suitable for injection molding, extrusion molding, and blow molding are all available. It is crucial during processing to avoid exceeding temperature limits or experiencing severe overpressure due to the formation of formaldehyde. The polymer should be thoroughly cleaned before shutdown to prevent overheating during startup. Acetal resins should be stored in a dry place. The apparent viscosity of acetal resins is less dependent on shear stress and temperature than polyolefins, but their melt has low elasticity and strength. The low melt strength poses a challenge in blow molding applications. Copolymers with branching structures are more suitable for blow molding. They crystallize rapidly, with molding shrinkage completing within 48 hours after molding. Transparent films are difficult to produce due to the rapid crystallization.