The first thing to understand here is that there is a much simpler, shorter description for polyoxymethylenes: acetals. The second thing is that, unlike other plastics that end in ‘ene’, for example polystyrene, polyethylene and polypropylene, acetals are engineering polymers, which means that they are a material with superior characteristics, particularly in the areas of strength and toughness, to the point where they are seen as an alternative to Nylon. Nylon is often used as an alternative to metals, so you get the point.
This strength and toughness means that one of the applications of acetals that you are likely to encounter on a daily basis is their use as clips, the kind that you find on all sorts of bags and rucksack straps that click together. This springy quality is what allows them, to a certain extent, to replace metal for tough applications. This springiness is also what makes this material suited for use as guitar plectrums. To get a sense of how it feels, you could think of another widely used application, which is opaque plastic pocket lights, with their slightly oily surface.
Image: Guitar plectrums by Dunlop
Key features
•Self-lubricating
•Waxy surface
•Excellent flex strength
•Excellent chemical stiffness
•Poor UV-inhibitor
•Poor clarity
•Recyclable
Sources
–Ultraform®
–Delrin®
–Celcon®
–Hostaform®
Cost
£2.35 ($3.70) per kg.
Sustainability issues
As a thermoplastic, POM is recyclable but the material is currently not being recycled in any large quantities.
Production
Standard thermoplastic techniques.
Typical applications
POM’s low-friction properties make the material a good choice for applications with moving parts, such as bearings, wheels and other mechanical components. The material is often used for its ability to flex and spring back again and again, which makes POM a suitable candidate to replace metals in many applications. Needs UV-inhibitor additive for applications that are exposed to daylight.
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–Widely available –Low friction –Strong and flexible –Recyclable |
–Only available in opaque grades –Requires an additive if the product is to be exposed to UV |