Patent · US Expired

Retortable composite closure for plastic containers

US4991731A · kind A · utility

20Cited by
3References
14Claims
0Family size

Assignee

Inventors

Key dates

Filing dateAug 3, 1989
Grant dateFeb 12, 1991
Priority date
Expiry dateAug 3, 2009

Classification

  • Technology area (CPC B)Performing Operations; Transporting
  • CPC primaryB65D51/145
  • WIPO fieldHandling
  • WIPO sectorMechanical engineering

Abstract

This invention relates to a closure which permits the opening of a hermetically sealed plastic container in a single action motion, which also maintains the hermetic seal under retort conditions. This closure includes a generally cylindrical side wall having threads along the inner surface thereof and a top portion having a metallic disk with its lower surface coated with a fusible coating, such as polypropylene. An annular flange is provided along the inner surface of the side wall to retain the metallic disk between the annular flange and an inwardly inclined inner surface portion of the side wall. A method is also disclosed for providing a hermetic seal on plastic containers using the closure of this invention.

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