device for absorbing asymmetric weight-bearing load with improved barrier material for control of diffusion pump

摘要

A product in the form of a cushioning device made from thermoplastic film containing crystalline material inflated to a relatively high pressure and sealed at the time of manufacture. The product maintains the internal inflatant pressure for long periods of time by employing a form of the diffusion pumping phenomenom of self-inflation in which the mobile gas is the gas components of air other than nitrogen. Improved and novel cushioning devices use new material, for the film of the enclosure nevelope which can selectively control the rate of diffusion pumping, thereby permitting a wider latitude flexibility and greater accuracy in the design of such new cushioning device, thus improving the performance and reducing cost of such devices while elminating some of the disadvantages of the earlier products. It is possible to permanently inflate certain types of new devices using readily available gases such as nitrogen, or air in which case nitrogen forms the captive gas.