Effect of MWD on the Amount of Polymer Process AID Required to Suppress Sharkskin Melt Fracture in LLDPE

Autor: H. Mavridis, K. Fronek
Rok vydání: 2002
Předmět:
Zdroj: Journal of Plastic Film & Sheeting. 18:45-57
ISSN: 1530-8014
8756-0879
Popis: At TAPPI-2000 it was reported [1] that different types of High-Performance Hexene Linear Low Density Polyethylene (HPH-LLDPE) behaved differently with respect to the onset of sharkskin melt fracture (SSMF), depending on the breadth of the molecular weight distribution (MWD). The MWD differences were small and subtle, but the effect on the onset of melt fracture was significant. The present study is a continuation of that work, through a comparative investigation under shear rate conditions high enough to induce melt fracture in both narrow and broad-MWD LLDPEs. A fluoropolymer process aid (PPA) was then added in stepwise increments until melt fracture was eliminated. It was found that the narrow-MWD resin required more than twice the amount of PPA to eliminate SSMF.
Databáze: OpenAIRE