Parison swell—A new measurement method and the effect of molecular weight distribution for a high density polyethylene

✍ Scribed by P. L. Swan; J. M. Dealy; A. Garcia-Rejon; A. Derdouri

• Publisher: Society for Plastic Engineers
• Year: 1991
• Tongue: English
• Weight: 529 KB
• Volume: 31
• Category: Article
• ISSN: 0032-3888
• DOI: 10.1002/pen.760311004

✦ Synopsis

Abstract

The measurement of parison swell is difficult because swell is a time‐dependent phenomenon and because, for a parison, two independent swell ratios must be determined. A new technique has been developed that makes use of a video camera focused on the end of the parison. Unlike previous techniques designed to measure time‐dependent swell, no oil bath is required. The new technique was used to study the effect of molecular weight parameters on the parison swell of high density polyethylene. For a series of blends of two resins having significantly different weight‐average molecular weights, the blends exhibited larger swell ratios than the base resins.