Multilayer multiphase rotational mouldings for inflatable sports balls - involving a two phase inner layer to optimise the physical performance of the ball

摘要

Mfr. of hollow mouldings having composite walls made by rotational casting of an outer skin of a monophase thermoplastic material (I) and an inner skin of two phase compsn. where the matrix phase material (II) has a higher tensile strength and modulus than (I) and the discontinuous phase material (III) is partially exposed and forms an interfacial bond with the outer skin layer (I). Used. esp. for mfr. of footballs, basketballs, volley balls, etc. The composite structure allows a surface layer of material chosen for its appearance and feel, to be complemented by an inner layer which modifies the physical properties of the ball to suit different inflation pressures, bounce characteristics etc. required for different sports.