 UBBFriend: Email This Page to Someone! |
 Plastic processing forums for extrusion information and advice and for other feed screw applications.
 Extrusion, Single Screw
 Reprocessing PS laminated with EVOH/EVA
|
| next newest topic | next oldest topic |
| Author | Topic: Reprocessing PS laminated with EVOH/EVA |
|
dh Member Posts: 2 |
posted July 14, 2004 01:01 AM
  
Hi Guys, We have an issue at our plant where we are trying to re-extrude the by-product generated from granulated PS that has been laminated with a EVOH/EVA film. What we are finding is we are getting a very poor surface finish to the sheet causing us to reject the product. I think it may have something to do with the possible immisciblity of the EVA component in the laminate. Some extruder details: (This is all I can think of relevance off the top of my head but if there is anything else which may be of relevance I can find it out) The strange part of this is that sometimes this has worked, even though the settings have not apparently changed from when it doesn't work. The only factor that seems to be different is that it seemed to work at the start of the run and then degrade over time. If anyone can assist on this it would be very appreciated. dh IP: Logged |
|
Steve H Moderator Posts: 308 |
posted July 14, 2004 04:02 AM
G'day DH Welcome to the single screw forum, give me a call at Evros Extrusion if you want to really discuss this. But basically the EVA should function as a compatibilizer in this blend, the crystalline nature of the EVOH is probably what's causing the problem. What is happening with the mechanical propeties of your sheet? The simplest way to overcome the cosmetic problem is to Co-Ex, with virgin PS outer layers and the blend as a core. There are some other things that you can try if co-ex isn't an option. Steve Hodgson ------------------ If at first you don't succeed, skydiving is not for you. IP: Logged |
|
zabielski Senior Member Posts: 323 |
posted July 14, 2004 06:42 AM
Contact KURARAY, as you need a compatilizer for the EVOH. The Grade is GF-30. Use rate is ~ 3% by weight of base EVOH. IP: Logged |
|
dh Member Posts: 2 |
posted July 15, 2004 07:32 PM
Thanks very much for the replies, they have given me at least a better direction to go in. A quick question though, do you have a trade name for this GF-30 as I have searched for it extensively but cannot find any reference to it. Cheers dh IP: Logged |
All times are ET (US) | next newest topic | next oldest topic |
  |
|
Contact Us | Feed Screw Designs
Powered by Infopop www.infopop.com © 2000
Ultimate Bulletin Board 5.45a
