Patent · US Expired

Envelope opening process and composition

US4228634A · kind A · utility

1Cited by
6References
8Claims
0Family size

Assignee

Inventor

Key dates

Filing dateAug 13, 1979
Grant dateOct 21, 1980
Priority date
Expiry dateAug 13, 1999

Classification

  • Technology area (CPC B)Performing Operations; Transporting
  • CPC primaryB43M7/004
  • WIPO fieldOther consumer goods
  • WIPO sectorOther fields

Abstract

In an envelope opening process in which an aqueous solution of a chemical degradation agent, such as tartaric acid is applied to envelope edges and the envelope edges are then heated and subjected to a mild mechanical action, penetration of the degradation agent through the envelope paper at its edges is assured by including in the aqueous solution from 2.5% to 30% of a glycol ether, such as ethylene glycol ethyl ether.

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