US Patent 7721781 Apparatus and method for forming inflated chambers

An inflatable web, and method and apparatus for inflating the web, which generally includes two sheets having inner surfaces sealed to each other in a pattern defining a series of inflatable chambers of predetermined length, each of the chambers having at least one change in width over their length; an inflation port located at a proximal end of each chamber, the inflation ports being formed by intermittent seals between the sheets; and longitudinal flanges formed by a portion of each of the sheets that extend beyond the inflation ports and intermittent seals.