Acetal or Delrin - recyclable???????

are these plastics recyclable - i can’t find any info on there recyclablity??

You don’t see acetal (Delrin is just a brand name) recycled very often because it’s not produced in the quantities like those of commodity resins like HDPE, LDPE, PP, PS, etc.

However, you should always mark your parts to identify the material so that it doesn’t contaminate other materials when the product is disassembled. The symbol for acetal is POM (stands for polyoxymethylene).

Delrin is a Dupont trademark for their acetal homopolymer resin plastic, so they are basically the same thing. Acetal is a thermoplastic (see later posts) and should be recyclable using typical methods like re-grinding.

The following was edited by the author in response to a later post:

I incorrectly thought that delrin was a thermoset plastic, which are cast to shape, and are hardened through heat and a one time only catalytic reaction. Because of this, they cannot be melted again for re-use like thermoset plastics. The only real use of recycled acetal (and any thermoset, for that matter) is grinding for use as filler material. This filler can be used in a thermoplastic matrix to increase bulk, for “beans” in fabric items (with a polishing step to remove sharp edgeds) or used loose in projects like road construction fill or concrete aggregate.

For more information, check out a search on thermoset recycling:

see i need delrin or something similar to have a high abrasion resistance yet it has to have a glass reinforment to give it that property

any other matierials that are plastic and have a high abrasion resistance and are recyclable??

Abrasion resistance in thermoplastics is tough, because their ability to melt also makes them flow under repeated friction/pressure, and that leads to wear.
Your best bet might be an insert of non-recyclable material as the bearing surface, and the bulk of the part molded in a thermoplastic for recycling. Plastic parts that are designed to take wear are almost always designed to be worn out and replaced, so recycling them is almost pointless. Plus, by making a replacable part, you contribute to re-use of the old product, which is even better than recycling from an energy standpoint.

Acetal is a thermoplastic not a thermoset.
What the hell are you doing giving advice on plastics when you don’t know shit?

Apologies to weeedogeee, and everyone else.

It does look like I don’t know shit :slight_smile: He’s absolutely right that acetal is a thermoplastic. I don’t know where I was getting my original information, but some further poking around the net learned me good.
Weeedogeee, do you have any experience re-grinding this stuff?

Efunda has some (correct) information on the polymer

Again guys, I’m really sorry. I try to know what I’m talking about, but you know how that goes.

I’ve tried to offer a general guideline for those looking for materials with good wear characteristics. I also wanted to clear up some confusion between some of these materials.

Check out this post:

Hope this helps,


That’s ok, I don’t mean to pick on you, but i read a lot of incorrect information on this site.
Acetal can be reground and recycled, but it’s usually used in such small quantites (gears, rotating comonents etc.) that it’s highly unlikely that it will end up being reused.

Maybe he should loook into using Rulon, which is a great bearing material with superior abrasion resistance and, in theory, the unfilled blend should be recyclable.

dude, thank you so much!!!

there not really speciffic about the fillers