Melt strength of polypropylene: its relevance to thermoforming.: An article from: Polymer Engineering and Science
Book Details
PublisherSociety of Plastics Engineers, Inc.
ISBN / ASINB00098K2EM
ISBN-13978B00098K2E5
AvailabilityAvailable for download now
Sales Rank13,493,279
MarketplaceUnited States 🇺🇸
Description
This digital document is an article from Polymer Engineering and Science, published by Society of Plastics Engineers, Inc. on November 1, 1998. The length of the article is 3878 words. The page length shown above is based on a typical 300-word page. The article is delivered in HTML format and is available in your Amazon.com Digital Locker immediately after purchase. You can view it with any web browser.
From the author: The melt strength of homopolymer, copolymer and high melt strength (HMS) grades of polypropylene (PP) was measured to assess the sagging resistance of PP for thermoforming applications. Acrylonitrile-butadiene-styrene (ABS), which can be easily processed during thermoforming, was also studied in this work. A polymer with high melt strength is considered to have a better sagging resistance. The melt strength measurements were carried out using a Gottfert "Rheotens" melt strength tester. The melt strength of the polymers increased with decreasing temperature and increasing extrusion rate. ABS generally had the highest melt strength in the low extrusion temperature region approaching the thermoforming region, indicating that it has a good sagging resistance during thermoforming. The HMS PP had significantly higher melt strength than conventional PP grades; therefore HMS PP is expected to have an improved sagging resistance. For conventional PP, melt strength was higher for the lower melt flow index (MFI) grades. A sharp increase in the melt strength was observed for conventional PP at low extrusion temperature, probably due to flow-induced crystallization of the PP. These results indicate that to minimise the sagging problem with conventional PP, low MFI grades should be used and thermoforming should be performed at temperatures close to the melting point of PP.
Citation Details
Title: Melt strength of polypropylene: its relevance to thermoforming.
Author: H.C. Lau
Publication:Polymer Engineering and Science (Refereed)
Date: November 1, 1998
Publisher: Society of Plastics Engineers, Inc.
Volume: 38 Issue: 11 Page: 1915(9)
Distributed by Thomson Gale
From the author: The melt strength of homopolymer, copolymer and high melt strength (HMS) grades of polypropylene (PP) was measured to assess the sagging resistance of PP for thermoforming applications. Acrylonitrile-butadiene-styrene (ABS), which can be easily processed during thermoforming, was also studied in this work. A polymer with high melt strength is considered to have a better sagging resistance. The melt strength measurements were carried out using a Gottfert "Rheotens" melt strength tester. The melt strength of the polymers increased with decreasing temperature and increasing extrusion rate. ABS generally had the highest melt strength in the low extrusion temperature region approaching the thermoforming region, indicating that it has a good sagging resistance during thermoforming. The HMS PP had significantly higher melt strength than conventional PP grades; therefore HMS PP is expected to have an improved sagging resistance. For conventional PP, melt strength was higher for the lower melt flow index (MFI) grades. A sharp increase in the melt strength was observed for conventional PP at low extrusion temperature, probably due to flow-induced crystallization of the PP. These results indicate that to minimise the sagging problem with conventional PP, low MFI grades should be used and thermoforming should be performed at temperatures close to the melting point of PP.
Citation Details
Title: Melt strength of polypropylene: its relevance to thermoforming.
Author: H.C. Lau
Publication:Polymer Engineering and Science (Refereed)
Date: November 1, 1998
Publisher: Society of Plastics Engineers, Inc.
Volume: 38 Issue: 11 Page: 1915(9)
Distributed by Thomson Gale
