The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Nov. 15, 1994
Filed:
Mar. 18, 1994
Applicant:
Inventor:
Phillip A Wagner, Essexville, MI (US);
Assignee:
The Dow Chemical Company, Midland, MI (US);
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
B32B / ;
U.S. Cl.
CPC ...
4283186 ; 264321 ; 264553 ; 4283179 ; 4283197 ; 4283199 ; 521139 ; 521146 ;
Abstract
A polystyrene foam sheet comprising a polystyrene resin which contains 1 to 15 wt. % of a rubber component having a majority of particle sizes less than about 0.45 microns has been found to be superior for forming deep drawn articles. Optionally one or two films may be extrusion coated or laminated to the foam sheet prior to thermoforming. Also disclosed is a method for thermoforming the foam sheet. Preheat the sheet, clamp the sheet between the matched male and female mold members, move the members into final position while applying a vacuum through both members to both sides of the foamed sheet and then chill formed foam to set a final shape.