Kynar® PVDF foam improves wire and cable jacketing properties

New foaming technology improves dielectric constant and shrink-back properties

Arkema Inc. has developed technology to manufacture Kynar® PVDF foam structures for wire and cable jacketing and insulation applications.  The technology is based on the patent-pending foam concentrate Kynar Flex® 2620 FC masterbatch resin.

"By foaming Kynar® PVDF, we can demonstrate an improvement in dielectric constant of greater than 50 percent," says Sean Stabler, Arkema's business development engineer for Kynar® PVDF fluoropolymer foams.  "The robust foam process shows the same dielectric constant improvements for both homopolymer and copolymer Kynar® resins," Stabler notes.

Shrink-back is an issue when temperature fluctuations cause jacketing on wire and cable to shrink from its original cut length.  It has been demonstrated that Kynar® foam jacketing is more resistant to shrink-back than solid Kynar® PVDF.  A long-term, high temperature annealing test shows that shrink-back is reduced 40 percent when using of Kynar® foam.  A short-term, lower temperature cycling study shows that shrink-back is reduced 20 percent when using Kynar® foam.

"A reduction in shrink-back using Kynar® foam is important," says Don Gaynor, Arkema's electrical industrial sales and market field manager for fluoropolymers in the Americas. "The low shrink characteristic of the cable jackets ensures the optical integrity of the cable during temperature changes from manufacturing to installation. Customers have expressed their desire for a fluoropolymer jacket that exhibits improved shrink-back properties, especially for fiber optic applications," Gaynor notes.

The foaming technology and specialized masterbatch has been developed over several years by the R&D group in Arkema's King of Prussia, PA laboratory. The masterbatch is sold in pellet form, which allows fine-tuning of foaming levels in any conventional extrusion process.

Kynar® and Kynar Flex® are registered trademarks of Arkema Inc.

A global chemical company and France's leading chemicals producer, Arkema is building the future of the chemical industry every day. Deploying a responsible, innovation-based approach, we produce state-of-the-art specialty chemicals that provide customers with practical solutions to such challenges as climate change, access to drinking water, the future of energy, fossil fuel preservation and the need for lighter materials. With operations in more than 40 countries, some 14,000 employees and 10 research centers, Arkema should generate annual revenue of approximately $8.3 billion, and holds leadership positions in all its markets with a portfolio of internationally recognized brands.