A Guide to Acetal and its Types

At Protocase, we offer the option to incorporate plastics in the manufacturing process in several ways. Examples include adding an acrylic window to your enclosures and 3D printing components. In this blog, we’re going to focus on a specific type of plastic – acetal.

What is acetal and why is it useful?

Acetal is an engineered thermoplastic with high tensile strength, stiffness, and fatigue endurance.

Designers and engineers typically use acetal to make clamps for cables or bus bars, fiber optic trays, panels, rack stands, and clamping brackets. It is also the material of choice when designing an opaque component.

Acetal has high resistance to moisture, organic solvents, and lubricants. It has great dimensional stability, which makes it perfect for close-tolerance machined parts. Due to its low friction, many of our customers specify acetal for enclosure components that slide on each other.

Acetal’s resistance to creep is excellent, meaning it won’t slowly deform over a long period of exposure to high levels of stress. As a result, it is a great option for parts that incorporate self-threading screws.

It also has good electrical properties, making it perfect for electrical applications requiring long-term stability. Acetal retains much of its toughness through a broad temperature range.

At the end of the day, acetal is an extremely useful plastic for many different applications.

Acetal types stocked at Protocase

We stock two different kinds of acetal, homopolymer and copolymer.

Before we deep dive into the specifics and the differences between the two, it’s important to understand polymers. On the chemical level, polymers are macromolecules – they are repeating patterns of smaller molecules called monomers. Monomers can be considered as the building blocks of polymers.

• Homopolymers are polymers with only one type of monomer
• Copolymers exist when there are two or more types of monomers

(This video from StudySession gives a good overview!).

The homopolymer acetal we stock is the brand name of Delrin. It has many of the same benefits as the acetal copolymers we have always stocked, but it is stronger because its crystalline structure is uniform. It is harder, so it is more resistant to impacts and abrasion.

Derlin generally has better mechanical properties such as higher tensile and yield strength, a lower friction coefficient, good electrical properties and tighter tolerances for machining.

Copolymers, meanwhile, are more resistant to hot water and strong solutions with high pH values than Delrin. Derlin, however, is still chemical resistant. It is also more tolerant to higher temperatures than acetal – although both are good on this front.

Copolymers are not as porous as Delrin can be. As a result, the former is better suited for medical or other applications where porosity is important.

Conclusion

So, it is generally best to use Delrin for applications which require strength, and use copolymers in areas which prioritize chemical resistance. Both are great for a wide range of applications. Copolymers are an excellent choice if your application doesn’t require superior mechanical properties as Derlin is slightly higher priced.

Protocase is here to manufacture your panels brackets and enclosures exactly as you envision in whatever quantity you require. We can help you to incorporate either type of acetal into your next project, whether they be copolymer or homopolymer.

If you require any help in deciding which type of acetal to use, do not hesitate to contact us. We can build custom enclosures and sheet metal parts in 2-3 days, with no minimum order. By working with us, you can revolutionize your workflow and simplify your part sourcing with the world’s fastest custom manufacturer.