Reusable heat pack containing supercooled solution and means for activating same
AssigneesMarc F. Fiedler, Herman Siegel
InventorsJoseph Stanley, Griffith L. Hoerner
Life of this patent
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Abstract
A heat pack is made by enclosing supercoolable aqueous sodium acetate solution together with a metallic activator strip in a sealed, flexible container. The activator strip is a flexible metal strip having one or more fissures or slits extending therethrough. To prepare the heat pack for activation, its contents are first heated to a temperature above the melting point of sodium acetate to completely melt it. Thereafter, the sodium acetate solution is supercooled. Activation or crystallization of the sodium acetate (with evolution of heat) is produced by bending the activator strip.
Claims12
A heat pack comprising:
- a flexible container;
- a supercoolable aqueous sodium acetate solution carried within said flexible container;
- and
- a flexible self contained activator strip disposed within said flexible container in intimate contact with said sodium acetate solution for initiating crystallization of said solution when supercooled, said activator strip having no dependency with said flexible container for said crystallization, said activator strip being formed from a ferrous material defining a thickness and a perimeter and including at least one fissure extending through said thickness and having a terminus inwardly of said perimeter.
A method of initiating crystallization of a supercoolable aqueous sodium acetate solution carried within a flexible container, said method comprising the steps of
- introducing a flexible activator strip into said supercoolable solution, said activator strip being formed from a ferrous material defining a thickness and a perimeter and including at least one fissure extending through said thickness and having a terminus inwardly of said perimeter;
- and
- flexing said activator strip through said flexible container to initiate crystallization of said supercoolable solution wherein said strip has no dependency with said container for crystallization.
Dependencies are inferred from the claim text.