Several constructions have been developed, some as early as the 1970s. In the 1980s, a number of inflatable cushion systems were documented. Before 2000, most inflatable air cushions used a single
check valve. However if one part of the cushion was punctured then this packaging would completely deflate. In 2002, several types of continuously independent one way air valve films were introduced. These patents incorporated a one way air valve film, which can be produced continuously and independently. If one air tube is punctured, the other air tubes will still remain inflated. ==Concept==