Patent · US Expired

Activator for initiating reaction in a heat pack and method for making same

US4872442A · kind A · utility

37Cited by
5References
6Claims
0Family size

Assignee

Inventor

Key dates

Filing dateSep 6, 1988
Grant dateOct 10, 1989
Priority date
Expiry dateSep 6, 2008

Classification

  • Technology area (CPC Y)Emerging Cross-Sectional Technologies
  • CPC primaryY10T428/12361
  • WIPO fieldThermal processes and apparatus
  • WIPO sectorMechanical engineering

Abstract

A highly reliable activator is provided for initiating the crystallization or destabilization of a super-cooled aqueous salt solution to cause generation of heat in a heat pack. The activator is characterized by a plurality of slits in a flexible metal article, with the opposing sides of the slits being in contact along at least a part of the length of the slit, and by an eroded and roughened surface on said article which comprises a number of minute metal nodules attached to and protruding from the surface, especially at or near the slit, which nodules are adapted to be detached or broken-off upon flexing of the activator. In addition the method of preparing said unique activator is provided which comprises tumbling said slit activators with an eroding material such as garnet powder to form the small nodules.

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