Patent ID: 7785219

Claim:
A method of manufacturing a game ball having a cover and a textile layer, the method comprising steps of: obtaining a closed cell, cross-linked, foam material manufactured through a process that includes: impregnating a polyolefin selected from the group consisting of low-density polyethylene, high-density polyethylene, polypropylene, and ethylvinylacetate with a nitrogen blowing agent having at least 99.9% purity, and expanding the polyolefin by heating the polyolefin above a softening temperature of the polyolefin, reducing a fluid pressure surrounding the polyolefin, and cooling the polyolefin to form the closed cell foam material; and incorporating the closed cell foam material into the game ball between the cover and textile layer, wherein the foam layer has a thickness ranging from 0.5 to 4.5 mm; wherein the method forms a game ball having a rebound ranging from 138 to 140 cm, and a size expansion of from 0.54 to 0.66 cm.