Injection Molding with Delrin®
Polyoxymethylene (POM) injection molding material, often referred to as Delrin® or acetal is an engineered thermoplastic material that is used to manufacture parts that require increased stiffness, low friction versatility and greater dimensional stability. Manufactured Delrin® plastic parts are generally created through either injection molding or extrusion processes and the finished material can be used for a wide range of applications. Overall, injection molding with Delrin® offers numerous advantages that make it a highly sought-after material within injection molding and extrusion circuits.
At Stack Plastics we specialize in the use of Delrin® for the manufacturing of plastic parts and materials. Since Delrin® is a homopolymer variation of polyoxymethylene (POM), Delrin® is often used in place of acetal plastic injection molding material.
Delrin® Polyoxymethylene (POM) Injection Molding Features
Delrin® maintains many beneficial features that make it a very valuable material for injection molding and extrusion applications. Some of the features that separates manufactured Delrin® plastic parts from other materials, includes:
- High resistance to repeated impacts
- Advanced mechanical strength & rigidity
- Endures fatigue
- Increased dimensional stability
- Excellent resistance to solvents, chemicals, moisture & gasoline
- Easily fabricated
- Designed to be used in a wide range of temperatures
Injection Molding with Delrin® vs Acetal Plastic Injection Molding
Acetal is the common name for a family of thermoplastics with the chemical name "PolyOxyMethylene", or POM. Acetal is available in two general types of resins: Copolymer acetal (POM-C), and homopolymer acetal (POM-H); commonly called Delrin®. The two different types of polyoxymethylene (POM) injection molding materials are described below.
Acetal copolymer offers increased dimensional stability due to its low levels of crystallinity. It is also resistant to hot water, high pH solutions and strong caustics. Acetal plastic injection molding also provides a lower coefficient of friction and better impact and wear properties, especially in wet or moist environments.
Delrin® acetal homopolymer offers slightly higher mechanical properties than acetal copolymer but may contain a low-density center (also known as "center line porosity") especially in large cross-sections. Delrin® also gives slightly less chemical resistance than copolymer acetal. Delrin® also provides greater stiffness, with increased flex, tensile and impact strength at room and elevated temperatures. Delrin® is also slightly harder than copolymer acetal.
Delrin® or Acetal, Which to Choose?
Both Delrin® and acetal provide significant benefits to their respective applications, with the requirements of the end application ultimately determining which material is used. Overall, Delrin® provides better mechanical properties than acetal, while acetal provides greater chemical properties than Delrin®. As an example, one of the most significant difference between injection molding with Delrin® and acetal plastic injection molding is that Delrin® produces an increased centerline porosity over acetal. However, Delrin® provides increased strength and stiffness, better creep resistance and higher Rockwell hardness rating than acetal.
Delrin® Polyoxymethylene (POM) Injection Molding Applications
Delrin® plastic parts that are manufactured through the injection molding process can be used for a wide range of applications over a spectrum of industries. Some of the more common applications related to injection molding with Delrin®, include:
- Conveyor parts
- Automotive parts
- Sporting equipment
- Electrical components
- Sliding & Guiding Parts