摘要 |
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. |