Patent · US Expired

Method of thermoforming

US4141771A · kind A · utility

22Cited by
7References
8Claims
0Family size

Assignee

Inventors

Key dates

Filing dateApr 6, 1977
Grant dateFeb 27, 1979
Priority date
Expiry dateApr 6, 1997

Classification

  • Technology area (CPC Y)Emerging Cross-Sectional Technologies
  • CPC primaryY10T428/31928
  • WIPO fieldOther special machines
  • WIPO sectorMechanical engineering

Abstract

A method of thermoforming a thermo-plastics sheet carrying a protective layer of polyethylene on at least one of the surfaces of the sheet comprising heating the assembly of sheet together with its protective layer to above the softening point of the thermoplastic and subsequently stretching the assembly to a desired shape.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.