Patent · US Expired

Manufacturing clear plastic lids

US3936265A · kind A · utility

3Cited by
5References
4Claims
0Family size

Assignee

Inventor

Key dates

Filing dateAug 15, 1974
Grant dateFeb 3, 1976
Priority date
Expiry dateAug 15, 1994

Classification

  • Technology area (CPC B)Performing Operations; Transporting
  • CPC primaryB29C48/10
  • WIPO fieldOther special machines
  • WIPO sectorMechanical engineering

Abstract

Continuous thermoplastic sheeting is manufactured by extruding thermoplastic material from a circular die to form seamless thin walled tubing. This hot, seamless tube is pressed together between a water cooled draw roll and a water cooled elastomerically coated roll to form sheet material which is transparent and without the speckled finish caused by included air.

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