Mmmmmm…Just thinking out loud here, but If it’s not Delrin and it’s a carbon copy of Delrin, I wonder how another company would get around the product copyright that US companies are so rabid in protecting? Unless of course another company produces it under license, but then again I thought that a company like Dupont would insist that their brand name would be on the subcontracted version of their product.
Who knows? The mystery thickens!!!
Delrin® is a trade name (which is protected) for -[-CH2-O]- Polyoxymethylene (aka polyacetal, aka a dozen different names because IUPAC and polymer chemists could never agree) . Originally made in the 50s it no longer is under patent, so generic versions can be made. I cannot think of a way copyright would apply.
In other words, you can make and sell tissue paper to wipe a nose, but you cannot call it Kleenex®.
That sums up the situation pretty well. I buy my Delrin from Mcmaster-Carr. They also offer a generic Acetal Copolymer, which is about 10% cheaper, but not available in as wide a selection of sizes. My choice has been to stick with the Dupont Delrin material since I know where it is coming from and it avoids having to get into long-winded explanations about what the flute is made of.
Dave Copley
Loveland, Ohio
Thanks for the enlightenment, I.D.10-t, dcopley, everything regarding ABS/Delrin/polymer etc is a lot clearer in my eyes. 
Edited to add: Sorry I.D.10-t, I may have got the wrong point across, what I meant was that I don’t think any company could make Polyoxymethylene and market it as ‘Delrin’, that would be a brand name copyright infringement. I also didn’t know that products like Delrin and such came under the same sort of limited copyright as songs, where after so many years (what is the figure exactly?) the copyright is lifted and the music comes into the public domain. I think that sucks if you are a songwriter/composer. 