METHOD & APPARATUS FOR MOLDING A HOLLOW OBJECT

摘要

A method and apparatus for open molding a one-piece hollow object involves an inflatable bladder having a predetermined shape when inflated for use as a male mold. Once inflated to a predetermined pressure, fiber reinforced plastic is applied to an outer surface thereof and allowed to cure. Once hardened, the fiber reinforced material defines rigid walls of the hollow object and the bladder is deflated and removed from within the object. The bladder is rotated about a horizontal axis during application and curing to allow access to all parts of the bladder and prevent sagging of the materials applied thereto. During application and curing, a relief valve prevents excessive increase in pressure levels within the bladder.