Described are balls, in particular a football, and a method for its manufacture. The ball comprises particles of an expanded material. As examples, the particles are connected, at least partially, to each other by radio frequency welding and/or infrared welding. As examples, the ball has a first layer of the particles of the expanded material, wherein the first layer is provided as an outer shell.

Particular embodiments described herein provide for a pickleball comprising a polymer outer shell, where at least a portion of the polymer outer shell is crosslinked. The pickleball with crosslinked material can be created by receiving manufactured non-crosslinked polymer pickleballs in consumer packaging in a bulk shipping container, removing the manufactured polymer pickleballs from the bulk shipping container, and passing the manufactured polymer pickleballs in the consumer packaging through an electronic beam to crosslink at least a portion of the polymer that comprises the pickleball to create the crosslinked polymer pickleballs.

The present invention relates to a freeze-drying mold and a method for manufacturing water-soluble polymer balls using the same, more specifically to a freeze-drying mold that is provided with a first mold having a plurality of first accommodation grooves formed on underside thereof and a plurality of discharge portions formed on top thereof to communicate with the plurality of first accommodation grooves and a second mold having a plurality of second accommodation grooves formed on top thereof to be facingly coupled to the plurality of first accommodation grooves of the first mold to thus provide a plurality of accommodation portions, and a method for manufacturing water-soluble polymer balls using the same. According to the present invention, the freeze-drying mold is capable of controlling the shrinkage rate of a solution in a freeze-drying process to make freeze-dried spherical materials, easily separating the made freeze-dried materials therefrom, and optimizing a drying efficiency thereof, and the method for manufacturing water-soluble polymer balls using the same is carried out so that the water-soluble polymer balls are constant in pore sizes and distributions, have high strength, and do not have any films on the surfaces thereof.

A pickleball ball is provided for increasing durability, improving performance, and/or reducing the loudness and/or frequency of sound generated when said ball strikes a paddle. The ball being a hollow ball comprised of a spherical shell defining a hollow cavity. The ball is made of a graphene-infused polymer material and the shell defines a plurality of holes distributed around the surface of the ball.