BARRIER COMPOSITE FILMS SEX WITH CORTICAL RE-FROST-PROOF WATER METERS, AND VOLUME EXPANSION ABSORBING MATERIAL AND ITS MANUFACTURING METHOD

The present invention relates to a volume expansion absorbing member for preventing the freezing of a water meter, having composite barrier films as shell materials and a manufacturing method thereof. The purpose of the present invention is to provide a volume expansion absorbing member having an oxygen barrier property and a moisture barrier property improved greatly by producing composite barrier films having a composite stacking structure in the process of combining a barrier layer having aluminum foil or an aluminum-deposited film as a substrate and a resin layer having a thermoplastic resin as a substrate, and composing the composite films as the shell materials of the volume expansion absorbing member for a water meter. To achieve the purpose, the present invention composes, as the shell materials of the volume expansion absorbing member, the composite barrier films having the composite stacking structure of the barrier layer having aluminum foil or aluminum-deposited films, which has an excellent moistureproof property and a gas barrier property, as a substrate and the thermoplastic resin layer satisfying other properties such as flexibility, resilience, a heat sealing property, cold tolerance, a waterproof property, impact resistance and scratch resistance. Therefore, the present invention prevents the freezing of a water meter efficiently by absorbing volume expansion in the water meter immediately because the volume expansion absorbing member satisfies resilience efficiency during repeated compression and expansion while keeping a designed volume constant simultaneously by completely preventing the swelling and softening of the volume expansion absorbing member which are induced by vapor permeation, and preventing the leakage of compressed air even after contacting with water for a long time.