Patent · US Expired

Process for transversely stretching polyethylene terephthalate film

US4238443A · kind A · utility

16Cited by
13References
9Claims
0Family size

Assignee

Inventor

Key dates

Filing dateAug 9, 1979
Grant dateDec 9, 1980
Priority date
Expiry dateAug 9, 1999

Classification

  • Technology area (CPC B)Performing Operations; Transporting
  • CPC primaryB29C48/08
  • WIPO fieldOther special machines
  • WIPO sectorMechanical engineering

Abstract

A process is disclosed for transversely stretching amorphous polyethylene terephthalate film wherein the temperature is adjusted to be substantially uniform across the web before stretching, heat is removed during stretching, and after stretching, the temperature is 1 to 15C..degree. lower and is uniform across the web.

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