The present invention provides methods for producing molded golf balls and the resultant balls. The methods of this invention involve producing foamed polyurethane covers and these methods help reduce dimple distortions and other surface imperfections. These golf balls contain an inner core and outer foamed polyurethane cover. One or more intermediate layers can be disposed between the core and cover. In one embodiment, a castable liquid polyurethane composition containing a foaming agent is dispensed into mold cavities, which are then pressed together to form a foam cover for the ball.

Multi-layered golf ball core sub-assemblies and the resulting golf balls are provided. The core structure includes an inner core (center) comprising a foam composition, preferably foamed polyurethane. The intermediate and outer core layers are preferably formed from foamed and non-foamed thermoset compositions. For example, the intermediate core can be formed from a thermoset rubber so there are adjoining foam core layers (inner and intermediate) and the outer core layer can be formed from a non-foamed thermoset rubber. The core layers have different hardness and specific gravity levels. The core assembly preferably has a positive hardness gradient extending across the entire assembly. The core structure and resulting ball have relatively good resiliency.

Golf balls and golf ball components made using three-dimensional (3D) additive manufacturing systems are provided. The golf ball includes at least one three-dimensional piece. Preferably, a continuous liquid interface printing method is used to make the three-dimensional structure. Ultraviolet (UV)-light polymerizable materials are used in the method. The method may be used to make single-piece or multi-piece balls. For example, the ball may include an inner core produced by the liquid interface printing method. An outer core layer may be disposed about the inner core, and a cover comprising inner and outer cover layers may encapsulate the core assembly to form the finished golf ball. The outer core and cover layers may be made using conventional molding technologies or the methods of this invention.

Multi-layered, golf balls having a core made of a foamed composition are provided. The core preferably has a foam inner core (center) and surrounding thermoset or thermoplastic outer core layer. The core also includes a structural insert such as, for example, a solid shell, perforated shell, a lattice or mesh, or a central hub with extending arms, and the like. The core layers have different hardness gradients and specific gravity values. The ball further includes a cover having at least one layer. By adjusting the respective specific gravity values of the core layers, the Moment of Inertia (MOI) of the ball can be increased or decreased. In one embodiment, the ball has generally good flight distance and low spin rate.

Multi-layered golf balls containing a dual-core structure are provided. The core structure includes an inner core (center) comprising a foam composition, preferably foamed polyurethane. The outer core layer is preferably formed from a non-foamed thermoset composition such as polybutadiene rubber. The core layers have different hardness and specific gravity levels. The specific gravity (density) of the foam inner core is preferably less than the density of the outer core layer. The core assembly preferably has a positive hardness gradient extending across the entire assembly. The core structure and resulting ball have relatively good resiliency.

Golf balls having a multi-layered core made of a foamed composition are provided. The core assembly preferably includes a foam inner core (center) and surrounding outer core layer. Preferably, a viscoelastic polyurethane foam composition is used to form the inner core. The foam composition has shape-memory properties. The core has good durability and thermal stability. In other instances, the viscoelastic polyurethane foam composition can be used to make the outer core layer. The core layers can have different hardness gradients and specific gravity values. The ball further includes a cover that can be multi-layered.

A method for making a golf ball having fiber flock bonded to a core is provided. The fiber flock preferably has high color vibrancy to provide high quality aesthetics. Preferably, the fiber flock comprises fiber segments having a length less than one inch. The fiber segments may have substantially equal dimensions. In other instances, the fiber segments are of unequal dimensions. The golf ball includes a translucent cover layer surrounding the core. Thus, the fiber flock is visible from the exterior of the ball. Special decorative effects can be achieved using colored fiber flock and reflective particulate such as pearlescent pigment in the layers surrounding the core.

Golf balls having a multi-layered core made of a foamed composition are provided. The core preferably has a foam inner core (center) and surrounding thermoset or thermoplastic outer core layer. Preferably, a polyurethane foam composition is used to form the foam center. The foam inner core preferably includes a fully-foamed center region and a partially or completely-collapsed foam outer region. The hardness of the fully-foamed region is different than the hardness of the collapsed foam region. Non-foamed thermoset or thermoplastic materials such as polybutadiene rubbers or ethylene acid copolymer ionomer may be used to form the outer core layer. The ball further includes a cover that may be multi-layered. The foam cores have good resiliency.

Methods for making golf balls and golf ball components using three-dimensional (3D) additive manufacturing systems are provided. The golf ball includes at least one three-dimensional piece. Preferably, a continuous liquid interface printing method is used to make the three-dimensional structure. Ultraviolet (UV)-light polymerizable materials are used in the method. The method may be used to make single-piece or multi-piece balls. For example, the ball may include an inner core produced by the liquid interface printing method. An outer core layer may be disposed about the inner core, and a cover comprising inner and outer cover layers may encapsulate the core assembly to form the finished golf ball. The outer core and cover layers may be made using conventional molding technologies or methods of this invention.

Multi-layered, golf balls having a core made of a foamed composition are provided. The core preferably has a foam inner core (center) and surrounding thermoset or thermoplastic outer core layer. The core also includes a structural insert such as, for example, a solid shell, perforated shell, a lattice or mesh, or a central hub with extending arms, and the like. The core layers have different hardness gradients and specific gravity values. The ball further includes a cover having at least one layer. By adjusting the respective specific gravity values of the core layers, the Moment of Inertia (MOI) of the ball can be increased or decreased. In one embodiment, the ball has generally good flight distance and low spin rate.