Patent ID: 7204278

Claim:
A structure of check valves for use in an air-packing device for protecting a product therein wherein the air-packing device has a plurality of air containers and is made of first and second thermoplastic films, comprising: a check valve film on which peeling agents of predetermined pattern are applied, said check valve film being attached to one of the first and second thermoplastic films; an air input established by one of the peeling agents on the air-packing device for receiving air from an air source; an air flow maze portion forming an air passage of a zig-zag shape, said air flow maze portion having an exit at an end thereof for supplying the air from the air passage to a corresponding air container having one or more series connected air cells; and a common air duct portion which provides the air from the air input to the air flow maze portion of a current air container as well as to the air flow maze portion of a next air container having one or more series connected air cells; wherein heat-sealing between the first and second thermoplastic films for air tightly separating two adjacent air containers is prevented in a range where said peeling agent is applied, and wherein said air passage in said air flow maze portion is created by heat-sealing the check valve film with one of the first and second thermoplastic films.