FLASH EXTURSION OF POLYVINYL CHLORIDE

• US 3,696,181 A
• Filed: 03/20/1970
• Issued: 10/03/1972
• Est. Priority Date: 03/20/1970
• Status: Expired due to Term

• Current Assignee: Willard Hallam Jr. Bonner
• Original Assignee: Willard Hallam Jr. Bonner
• Inventors: Bonner, Willard Hallam Jr.
• Primary Examiner(s): Frome, Julius
• Assistant Examiner(s): Leipold, Paul A.
• Application Number:
  US05/021,454
• Time in Patent Office: 928 Days
• Field of Search: 260/2.5E,2.5P 264/53
• US Class Current: 264/53
• CPC Class Codes: B29C 44/50 using pressure difference, e.g. by extrusion or by spraying B29C44/468 takes precedence
• CPC Class Codes: B29K 2027/06 PVC, i.e. polyvinylchloride
• CPC Class Codes: C08J 9/144 containing carbon, halogen and hydrogen only
• CPC Class Codes: Y10S 264/05 Use of one or more blowing agents together
• CPC Class Codes: Y10S 521/907 Nonurethane flameproofed cellular product
• CPC Class Codes: Y10S 521/91 Plural blowing agents for producing nonpolyurethane cellular products

Abstract

A flexible, low density foam of polyvinyl chloride having closed polyhedral-shaped cells and very thin cell walls of uniform thickness is produced by flash extruding a solution of the polymer in a methylene chloride solvent under conditions such that the temperature of the product immediately after extrusion is above the boiling point of the solvent, but below the stability temperature of the foam. The resultant foam material is useful as a cushioning material.

Claims

2. The process of claim 1 wherein the polymer foam is extruded in the form of a filament.