Article |

Nissel strongly defends sheet extrusion

The companies that calender plastic resin into sheet for packaging applications managed to "pull the wool" over the usually perceptive eyes of PW editors, according to Frank Nissel.

He's president of Welex Inc. (Blue Bell PA) a major manufacturer of extrusion sheet line equipment. He referred to the report on calendering published in the June issue (see p. 26). According to Nissel calendering is "never" used if extrusion can also process a polymer because extrusion is less expensive and more flexible. And he says in a letter to PW the tolerances and sheet quality are the same for both processes. Thermal instability of resin often drives producers of polyvinyl chloride and Barex® modified acrylonitrile toward calendering instead of extrusion. However Nissel says that certain sheet suppliers have created a profitable niche by extruding PVC with qualities that cannot be matched by those produced via calendering. Nissel concludes that the article on calendering "was planted as a last ditch defense of PVC as the clear sheet...and nobody mentioned chlorine or recyclability." Despite the long experience of Frank Nissel PW editors believe that its report was both accurate and informative.

Related Sponsored Content

E-Book Special Report
Total Cost of Ownership
Sign up to receive timely updates from our editors and download this E-Book Special Report to learn how to calculate the true Total Cost of Ownership (TCO) of your packaging machinery.


Don't miss intelligence crucial to your job and business!
Click on any newsletter to view a sample. Enter your email address below to sign up!
Each newsletter ranges in frequency from once per month to a few times per month at most.