Delrin® versus acetal
There are 2 different types of acetal resins available: acetal homopolymer and acetal copolymer, each with their own advantages & disadvantages.
Delrin (acetal homopolymer)
Delrin® acetal is a crystalline plastic made by the polymerization of formaldehyde, offering an excellent balance of properties that bridge the gap between metals and plastics. Delrin® offers the manufacturing features of plastic fabrication and competes with other engineering materials on a cost and performance basis.
Acetal (acetal copolymer)
Acetal copolymer is an engineering thermoplastic used in precision parts requiring high stiffness, low friction, and excellent dimensional stability. It is resistant to hot water, hydrocarbons and solvents and possesses good bearing and wear properties.
Delrin® and acetal are both FDA & USDA compliant.
Delrin® (homopolymer) advantages over acetal
Tensile strength is 10-15% higher than co-polymers
Higher impact strength at room temperature and low temperatures
Slightly harder than copolymer acetals
Slightly higher continuous use temperature than copolymer (95°C vs. 90°C)
Superior impact and creep resistance
Acetal (copolymer) advantages over Delrin®
Better chemical resistance with high pH (basic) solutions
Improved dimensional stability over comparable homopolymers formulations due to its lower level of crystallinity
Good wear and abrasion properties **Lower centerline porosity than Delrin® homopolymer (excessive centerline porosity may cause void)