Abstract: A method for making a ball having a cover and a core, which core has a spherical center and a winding, is disclosed. The ball is made by foam injection molding a thermoplastic resin comprising a mixture of at least about 45% of a copolymer of at least one olefin with at least one unsaturated monocarboxylic acid to form a spherical partially blown center. The center is then wound to form a wound core which is immersed in an adhesive which impregnates the yarn. The wound core is then dried and ironed the melt the surface of the center so as to fuse the windings to the center. A cover is then applied to the core to form the completed ball.

Abstract: A ball, such as a baseball or softball, which includes a thermoplastic resin center, an outer winding and a two-piece cover is disclosed. The core comprises at least 45% of a partially blown copolymer of at least one olefin with at least one unsaturated monocarboxylic acid which is wrapped with a suitable winding impregnated with a latex based adhesive which winding is heat fused to the outer surface of the thermoplastic resin center. The partially blown spherical center has a micro cellular structure wherein the cells increase in number and decrease in size radially outward from the center. The core, consisting of the thermoplastic resin center and winding which is heat fused thereto, is covered with a two-piece stitched cover. The process for making the described ball is also disclosed.