A manufacturing method for seamless manmade leather ball mainly comprises a inflatable ball bladder having a peripherally wrapped around binding yarn or cloth thereon to form a reinforcement layer is protrudingly made with an air charging inlet, wherein the manufacturing method is the following:
- Composites such as soft bioplastic resin or manmade leather, etc are injected, extruded or hot compressed to form hemisphere shaped upper half bowl type thin cover and lower half bowl type thin cover to completely matchingly sleeve and sphere the corresponding ball bladder ready for inflation to ball shape;
- Subsequently, said ball bladder enclosed by bowl type thin covers being put into the hemisphere shaped curing molds being capable of opening and closing in vertical direction and having a temperature heating control device is pressingly combined under the pressure of the same spherical shape and size and at the medium temperature condition set to suit for resin compound softening for softening the resin content of said thin covers to paste with reinforcement layer and thereby making the corresponding middle section seam edges to be integrated into one, and allowing inside surfaces of thin covers to fusionly paste on the periphery of ball bladder so as to become the initial blank;
- Secondly, said initial blank while being continuous pressingly combined can be through the temperature control device of the same curing molds to raise the temperature thereof up to the high temperature curing condition for foaming or not foaming resin compound;
- or the said initial blank is removed from said curing molds to be further put in another curing molds with temperature set to high temperature curing condition for foaming or not foaming resin compound to be further pressingly combined under the pressure of the same ball shape and size, and at the high temperature for curing, i.e. the ball bladder is completely pasted by said thin covers at the external periphery thereof to become an initial blank with water proof layer, and further after the curing molds are opened, the initial blank with completely adapted water proof middle layer and reinforcement layer;
- Furthermore, said initial blank while still hot can be put in another set of semi-spherical shaped bowl type forming molds being capable of opening and closing in vertical direction for pressing combination, formation and cooling treatment once again, wherein inside surfaces of forming molds for low temperature and cooling use are designed to pre-form different types of shaping blocks thereon or distributed seams alike convex or concave engraved lines thereon according to ball outlook or modeling, whereby said upper and lower bowl type thin covers with residual warm, and thermoplastic surfaces are pressingly combined by said forming molds to form a seamless base body with overall distributed shaping blocks or reversed seam lines of concave or convex engraved lines after the molds are reopened;
- In continuity, surface of base body can be further selectively soaked, spray coated, smeared, or wrapped by a leather film for transparent or non-transparent surface cortex layer treatment by manmade leather material to complete the manmade leather ball manufacture, wherein pre-made lines area covered by said cortex layer of the same thickness is formed to decorative lines of same concaveness, wherein it is characterized for the multiple economic and convenient benefits achieved through manufacture simplification, product standardization and human error reduction, etc.