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:
Mar. 06, 1979
Filed:
Dec. 01, 1977
James F Pilgrim, Elginburg, CA;
Ronald A Hunter, Kingston, CA;
Du Pont of Canada Limited, Montreal, CA;
Abstract
An improved process for coating sheet substrates with thermoplastic polymer is disclosed. In the process the sheet substrate forms one die lip of the extrusion coating die. The sheet substrate is passed from face-to-face contact with the metal block of the extrusion coating die into a spaced apart relationship with one die lip of the extrusion coating die, the sheet substrate forming the second die lip. Molten thermoplastic polymer is extruded into the space between the one die lip and the sheet substrate, thereby coating the sheet substrate with polymer. The preferred polymer is a poly-.alpha.-olefin, especially polyethylene or a copolymer of ethylene and butene-1. The preferred sheet substrate has orifices in the surfaces thereof. The process may be used to coat sheet substrates with a thermoplastic polymer, e.g. in the manufacture of form boards for the construction industry.