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Glossary » Materials » Polymers » Polyacetal » 25% Glass Coupled

25% Glass Coupled Acetal is a subcategory of Polyacetal. The additative is added by weight during the manufacturing process. Its elastic modulus ranges from 1250 to 1400 MPa. Its tensile strength ranges from 16000 to 18500 MPa at break. Its flexural strength ranges from 18000 to 28000 MPa. Its Izod Impact strength ranges from 1 to 1.8 J/cm. Its elongation at break ranges from 2 to 3 %. Its hardness ranges from 79 to 90 Rockwell M. Its specific gravity ranges from 1.58 to 1.61. Its coefficient of thermal expansion ranges from 17 to 44 x 10^-6/°C. Its melting temperature ranges from 160 to 180 °C. Its molding pressure ranges from 8 to 20 MPa.

Polyacetal, also known as Acetal, is a thermoplastic. Common trade names are Delrin and Ultraform. copolymer It is a lubricious, strong, and resistant to creep and fatigue. It has good dimensional stability and relatively high abrasion and chemical resistance. Acetal is commonly used in quality toy parts, handles, knobs, and bearing parts. Delrin is approved by FDA for use in the food industry. Acetal resins were commonly used in the plumbing industry. However, they are sensitive to chlorine which leads to cracks in acetal plumbing fittings. The widespread failure of acetal moldings in potable and hot water supplies resulted in one of the largest class actions in the USA when acetal plumbing fittings cracked and caused floods of many homes in many states.