Materials
Golf balls are made mostly of plastic and rubber. Two-piece balls have a solid rubber core and a thermoplastic cover. These are longer-lasting than three-piece balls and account for 70 percent of golf ball production. Two-piece balls can be made in one day. First, the ball’s center must be formed. In a two-piece ball, the rubber begins as a hard block. It is heated and pressed to form a sphere that is about 1.5 inches in diameter. The smaller and heavier a ball, the farther it will go. Golf ball specifications are regulated by the Royal & Ancient Golf Club of St. Andrews and the United States Golf Association, according to the International Rubber Products Exhibition Centre (IRPEC).
Molding
Either compression molding or injection molding is used to form the ball’s cover, as well as its dimples, according to IRPEC. With injection molding, the core that was formed earlier is centered in a mold and held by pins. Molten thermoplastic is injected into the mold. Pressure as well as heat join the cover material with the center, forming the ball’s dimpled shape. As the plastic hardens, the pins are taken out.
If compression molding is used, the ball’s cover is molded into two hollow hemispheres via injection. The hemispheres are positioned around the ball’s core. This is pressed together and heated with a mold that fuses the core and cover to each other. The mold also forms the dimples. Compression molding results in fewer cosmetic defects than injection molding.
Finishing
After molding is complete, any rough spots on the ball as well as the seam on the ball’s molded cover are removed. Two coats of paint are then put on the ball. The ball sits on a couple of posts that spin so that the paint can be applied uniformly. The ball is stamped with a logo, and a clear coat meant to add sheen and help resist scuffs is applied, according to How Products Are Made. Balls made of thermoplastic resins can sometimes skip the painting step, because these resins can be blended with colors during processing, according to IRPEC. Painted balls are placed in a large dryer. After they are dry, they are packaged and readied for distribution.
Three-Piece Balls
The three-piece ball has a solid rubber center that is smaller than the two-piece ball's. Some three-piece balls are liquid-filled in the center. A rubber thread is wound around the ball’s center under tension. A rubber cover is then added. Three-piece balls can take up to a month to produce. They are all compression molded. Injection molding would cause problems because the hot plastic flowing through might distort and cause breaks in the rubber threads.
Member Comments