Patent · US Expired

Forming process for light gauge polymer sheet material

US4294640A · kind A · utility

5Cited by
10References
5Claims
0Family size

Assignee

Inventors

Key dates

Filing dateDec 12, 1979
Grant dateOct 13, 1981
Priority date
Expiry dateDec 12, 1999

Classification

  • Technology area (CPC Y)Emerging Cross-Sectional Technologies
  • CPC primaryY10T156/103
  • WIPO fieldAudio-visual technology
  • WIPO sectorElectrical engineering

Abstract

A method for cold-forming light gauge polymer sheet material by application of localized heat to the area of the fold. In the manufacture of Lexan polycarbonate flexible magnetic disk jackets, heat is applied to the folded corner by a heater bar generally maintained uniformly at 375.degree. F. The heater bar contacts the folded Lexan polycarbonate edge in a U-shaped trough having planar side walls generally perpendicular to a planar bottom wall.

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