Hello,

I've recently been cast into the world of injection molding and wondered if anyone could offer some insight into one of the challenges we've encountered. This is probably going to be a stupid question, but here goes:

One of our products is a carbonation vessel with a threaded cap, injection molded using a thermoplastic elastomer (NEWMAT "Easiprene" SBS/SEBS). It is used primarily in restaurant/bar environments, so it's exposed to all the imagined elements. We've been very happy with the functionality and white/natural color aesthetic with one exception - after a few months they begin to yellow, sometimes drastically, which leads me to my question:

Are there other TPEs we could use that resist this yellowing effect, or is it almost always a feature of additives, stabilizers, etc.?

Any suggestions or keywords you could throw my way would be much appreciated.

Thanks so much

Click image for larger version. 

Name:	Perlini discoloration 2.jpg 
Views:	11 
Size:	11.9 KB 
ID:	298