| 摘要 |
PURPOSE:To enhance economical efficiency by making re-use possible, by sealing not only a supercooled liquid of sodium acetate in a liquidtight bag but also a metal trigger for crystallizing the supercooling liquid. CONSTITUTION:A sodium acetate supercooled liquid 2 and a metal trigger 3 are sealed in a flat liquidtight bag 1 constituted of a plastic sheet. When the metal plate 5 of the metal trigger 3 is pressed from the outside of the bag 1 by a finger, the metal plate 5 formed into a curved surface shape expanded upwardly at the central part thereof is elastically deformed to be depressed and restored by elasticity. At this time, the free pieces generated by the slits 5a provided to the metal plate 5 are also elastically deformed. By this mechanism, a sonic wave or shock wave is generated and the sodium acetate supercooled liquid 2 in an unstable state within the bag receives said wave to be ready to return to a stable state and begins to crystallize to generate a large quantity of heat at the time of crystallization. Therefore, the bag 1 can be used as a portable heat insulating device. |
