W. R. Grace Co.

W. R. Grace & Co., Cryovac Div.

W. R. Grace & Co., Cryovac Division

Frederick D Stringer

Michael D Esakov

Daniel J Ferguson

Raymond B Dacey

David C Hudgens, Jr

Daniel F Ferguson

A heat sealable and shrinkable, coextruded, multi-layer packaging film having a propylene homopolymer base layer and a skin layer of a preferred blend of 60% to 80% propylene-ethylene copolymer with propylene homopolymer provides a sealing temperature range of up to 30.degree. C.

Heat sealable, multi-ply polypropylene film

In the process of extruding tubular thermoplastic film or tape, the production rate can be improved by using a smooth support plug to stabilize and shape the extrudate after it has been cooled and at least partially solidified. A principal function of the support plug is to assist in supporting the long slender column of partially solidified extrudate which is above the plug. The result is a significant increase in the output of the extrusion process.

Method and apparatus for high speed extrusion of thermoplastic materials

A generally cylindrical core for winding a web of sheetlike material has portions with a lesser diameter than other portions such that otherwise baggy areas of the web overlie the lesser diameter area of the core. The core particularly solves the problem of elongated edges on a wound film of heat shrinkable thermoplastic material caused by differential shrinkage about a core.

Winding core for heat shrinkable film material

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Greenville, SC, United States of America

Frederick D Stringer