Yahoo Answers is shutting down on May 4th, 2021 (Eastern Time) and beginning April 20th, 2021 (Eastern Time) the Yahoo Answers website will be in read-only mode. There will be no changes to other Yahoo properties or services, or your Yahoo account. You can find more information about the Yahoo Answers shutdown and how to download your data on this help page.
Trending News
what is extrusion process? How the HDPE,LDPE and PVC and PU films aremade from the raw materials?
Polyester film and PVC sheetings are made from raw materials in granules form .By which process the end products are made and by which type of machineries ? Whether the same machineries can be used for Polyurethane raw materials to take out endproducts in Polyurethane??
2 Answers
- MeisəMLv 41 decade agoFavorite Answer
I think these links will help:
http://en.wikipedia.org/wiki/Extrusion
- 1 decade ago
HDPE and LDPE are essentially the same thing: polyethylene. They are just made with different amounts of additives to control the number of branching to the main chains. PVC is polyvinyl chloride. It comes from Vinyl chloride and made into chains.
To be made into films, you need the film extruder or the blow film extruder. There are the differences there due to the techniques used to extrude the themoplastics.
PU, however, is slightly different as you need to consider whether to make permanently set it as a thermoset or let it stay as a thermoplastic. As the setting (i forgot the term, sorry) agent is added in, it hardens easily. Blow film is not used as the plastic is quickly cooled as air passes through the hole. Film extruder is a better choice as it slowly cools the film for better clarity.
