Acetal Copolymer vs Delrin® Acetal Homopolymer

Acetal Copolymer Alternative | DuPont™ Delrin®

It’s more than acetal – it’s DuPont Delrin®.

Unlike acetal copolymers, Delrin®  is a tough, lightweight and durable acetal polymer with inherent low friction, low wear, low noise, low moisture pick-up and excellent spring back properties, invented by DuPont.It's so well known that the brand name Delrin® is often misused as the industry term for acetal resin. But, not all acetals are equal.

The uniform, larger crystalline block structure of Delrin® provides better internal bonding

How is Delrin® different?

Delrin® is an acetal homopolymer and has a uniform backbone with a larger crystalline block structure than acetal copolymers providing better chemical bonding. As a result, Delrin® is the stiffest and strongest unreinforced technical engineering polymer available. 


Delrin® offers major benefits over acetal copolymer

Specifying Delrin® for highperformance, high precision mechanical parts can allow to optimize part design and production :

  • Increased design flexibility
  • Thinner wall sections at same physical part performance
  • Lighter parts 
  • Less material usage
  • Improved mold filling
  • Shorter molding cycle times
  • Upgrading from existing tooling delivers higher performance parts
  • For new part design and upgrading with current molds 
  • Potential for reduction in part production cost (customers quote up to 20%)

Delrin® offers the potential for reduced material usage and shorter molding cycle times

Mechanical properties comparison

For example, Delrin® 500P, our general purpose resin, significantly outperforms general purpose acetal copolymer across the entire mechanical spectrum: 

  • 80% higher yield strain
  • 65% higher flow rate
  • over 40% higher impact resistance, particularly at low temperature
  • higher stiffness, yield strength, strain at break and creep resistance
  • >1000% higher flex fatigue resistance


Delrin® Properties Customer Benefits
Higher Yield Stress and Yield Strain
  • Better memory of original shape after deflection
  • Useful for snap-fits/buckles and simplicity in assembly
Higher Modulus
  • Stiffer material allows design of thinner-walled parts leading to more efficient use of resin
Higher Flow Rates with Better Mechanical properties
  • Better filling of thinner-walled cavities
  • Useful for effectively designing thin-walled parts
Much Higher Notched Charpy Impact Strength, even at Low Termperatures
  • Parts that are more resistant to fracture and capable of absorbing much more energy
  • Useful for gears in motors that change directions or stop abruptly and mechanical/moving components in refrigerated environments
Higher Strain at Break
  • Contributes to overall toughness of part
  • Allows deflection farther past yield point w/o part failure
  • Useful for snap-fits and buckles
Higher Creep Resistance
  • Better maintains overall shape over long exposures to loads
  • Maintains tighter fit in snap-fit applications 
  • Better maintains dimensions in spring-loaded applications
Much Higher Fatigue Resistance
  • More durable in high-cycle applications like continuously running gears

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