US Patent 7192547 Method for manufacturing a golf product

A process for reaction injection molding a polyurethane material for a layer of a golf ball is disclosed herein. The layer is preferably a cover for the golf ball. The process discloses preferred pressure parameters and mass flow parameters for reaction injection molding the layer. Such preferred pressure parameters include the difference from mix-head open to the shot mid-point, ΔΔPom, and the pressure difference from mix-head open to close, or ΔΔPoc. The mass flow parameters include the percentage change in mass flow ratio from mix-head open to shot mid-point, or % MFRom, and the change in mass flow ratio from mix-head open to shot mid-point, or ΔMFRom.