| 主权项 |
1. An automatic inside-mold coloring method for stitches on a cover of a molded baseball or softball, comprising steps of:
forming a ball core; placing a fiber layer serving as a base of a consistent thickness around the ball core, then infusing liquid Polyurethane (PU) material into and impregnating said fiber layer ; attaching and aligning a masking jig onto an inner side of a ball cover mold having multiple stitch-shape grooves, with said masking jig having notches configured to expose said stitch-shape grooves on said inner side of said ball cover mold while covering the rest of said inner side of said ball cover mold; using hands to apply or using a spraying tool to spray a coloring material on said masking jig to fill said coloring material in said stitch-shape grooves of said ball cover mold with the rest of said inner side of said ball cover mold shielded by said masking jig; removing said masking jig from said ball cover mold; placing said Polyurethane-soaked ball core inside said ball cover mold, and then putting said ball cover mold encased with said soaked ball core into a metal mold holder for said ball core to tightly engage with said ball cover mold; heating up said ball cover mold, and curing said Polyurethane-impregnated fiber layer around said ball core inside said ball cover mold at 70° C. for 2 hours; and removing a finished ball having two figure-8 shape rows of bulged stitches formed integrally with said coloring material thereon from said ball cover mold and said metal mold holder. |
