Trexel, Inc.

Matthew Pallaver

Sung W Cha

Nam Pyo Suh

James F Stevenson

Jere R Anderson

Roland Y Kim

Theodore A Burnham

Robert H Walat

Continuous polymeric extrusion nucleation systems and methods useful for making polymeric microcellular foamed materials, including crystalline and semi-crystalline polymeric microcellular materials, are provided. Pressure drop rate is an important feature in some embodiments, and the invention provides systems for controlling these and other parameters. One aspect involves a multiple-pathway nucleator that is separated from a shaping die by a residence chamber. Another aspect involves a die for making advantageously thick articles, including a multiple-pathway nucleation section. Microcellular material can be continuously extruded onto wire, resulting in a very thin, essentially closed-cell microcellular insulating coating secured to a wire. Other very thin microcellular products can be fabricated as well.

Method and apparatus for microcellular polymer extrusion

Microcellular thermoplastic elastomeric polymeric structures are provided. The articles have an average cell size of less than 100 &mgr;m and a compression set ranging from less than about 30% to less than about 5%, and a rebound value of at least 50%. The articles may be formed from a thermoplastic elastomeric olefin, preferably metallocene-catalyzed polyethylene. The density of the articles ranges from less than 0.5 gm/cm to less than 0.3 gm/cm .

Microcellular thermoplastic elastomeric structures

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Lexington, MA, United States of America

Matthew Pallaver