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Reusable Heat Pack

IP.com Disclosure Number: IPCOM000250000D
Publication Date: 2017-May-15
Document File: 2 page(s) / 155K

Publishing Venue

The IP.com Prior Art Database

Abstract

Our concept utilizes a modified heat pack construction. Water is incorporated into the heat pack on one side of a thin film composite (TFC) membrane with a one way check valve; calcium chloride crystals are on the other side (separated from the water via the TFC membrane and check valve). To activate the pack, you squeeze on the water side which pushes the water through the check valve and mixes with the calcium chloride. The exothermic reaction can raise the temperature to 130 F for 60-90 mins and can be tailored simply by adjusting the mass of calcium chloride and the volume of water in the heat pack. (For reference, for the sodium acetate, supercooled heat packs achieve the same operating parameters.) To reverse the process, the bag is squeezed on the side now containing the salt mixture. The pressure is sufficient to force the water through the TFC while rejecting the salt. This can be accomplished either by hand or via a mechanical assist device (such as a mechanical compression device, a toothpaste tube winder, or a manual pump).

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Reusable Heat PackABSTRACT

Described is a concept that utilizes a modified heat pack construction.

Water is incorporated into the heat pack on one side of a thin film composite (TFC) membrane

with a one-way check valve; calcium chloride crystals are on the other side (separated from the

water via the TFC membrane and check valve). To activate the pack, you squeeze on the water

side which pushes the water through the check valve and mixes with the calcium chloride. The

exothermic reaction can raise the temperature to 130 F for 60-90 minutes and can be tailored

simply by adjusting the mass of calcium chloride and the volume of water in the heat pack. (For

reference, for the sodium acetate, super cooled heat packs achieve the same operating

parameters.) To reverse the process, the bag is squeezed on the side now containing the salt

mixture. The pressure is sufficient to force the water through the TFC while rejecting the salt.

This can be accomplished either by hand or via a mechanical assist device (such as a mechanical

compression device, a toothpaste tube winder, or a manual pump).

TFCs are "typically made out of a thin polyamide layer (<200 nm) deposited on top of a

polyethersulfone or polysulfone porous layer (about 50 microns) on top of a non-woven fabric

support sheet. The three-layer configuration gives the desired properties of high rejection of

undesired materials (like salts), high filtration rate, and good mechanical strength. The

polyamide top layer is responsible...