Patent ID: 7208215

Claim:
A reusable composite film comprising: a composite layer of resilient and nontoxic material having a thickness between a top surface and a bottom surface; a sealing layer coated onto the top surface of the composite layer; and a plurality of micro-gaps distributed within at least a pre-selected area of the composite layer, wherein each of the micro-gaps traverses the thickness of the composite layer from the bottom surface to the top surface, wherein in a static state with no pressure exerted on the composite layer, each of the micro-gaps is in a normally closed condition to prevent air permeation through the composite layer, each of the micro-gaps comprising a split upper seam portion with edge ridges demonstrated on the top surface of the composite film and a close lower seam portion on the bottom surface of the composite layer in communication with the split upper seam, wherein the sealing layer coated onto the top surface of the composite layer at least in the pre-selected area on the composite layer holds the plurality of micro-gaps in the normally closed condition to prevent air and water permeation through the micro-gaps, wherein when pressure and heat are exerted on the bottom surface of the composite layer in the thickness direction, the initially closed lower seam portions become split and the sealing layer separates from the composite layer without fracturing to allow the split upper seam portion to expand to facilitate pressure regulation, wherein when pressure and heat is removed from the bottom surface of the composite layer, the sealing layer re-seals to the top surface of the composite layer and the plurality of micro-gaps return to the normally closed condition to prevent air permeation through the composite layer such that the composite film can be reused to regulate another increase of pressure exerted against the bottom surface of the composite layer in the thickness direction.