Patent ID: 8443793
Filing Date: 2013-05-21
Classification: B65D

Abstract:
1. A moisture resistant flexible package for a moisture-activated chemical heater, comprising: an outer sheet; an inner sheet consisting of a rapidly quenched, low crystallinity polypropylene, wherein the inner sheet is substantially superposed and attached to the outer sheet along three contiguous sides thereof forming permanent opposing side seams and a permanent bottom seam intermediate the permanent opposing side seams thus defining an elongated flexible envelope having an open top end opposite the permanent bottom seam, a fold defined by folding the envelope over on itself; and temporary side seams formed by heat sealing the polypropylene inner sheet to itself; and a removable top seam intermediate the temporary side seams securing the envelope in a folded position to form a continuous moisture barrier surrounding a moisture activated chemical heater disposed in the envelope; wherein the heater can be opened for use by opening or removing the top seam and unfolding the envelope by opening the temporary side seams to provide the unfolded envelope, the outer and inner sheets remaining sealed along the permanent side seams and permanent bottom seam while allowing access inside the envelope via the open top end.