| 摘要 |
A method for the continuous production of completely or partly foamed thermosetting polymerizable plastic articles, such as pipe insulation shells or sleeves. One or more sets of justaposed mold-carrying endless conveyors are employed wherein one conveyor of each set supports a series of longitudinally contiguous mold halves complementary with a series of longitudinally contiguous mold halves supported by the other conveyor of the set. The conveyors are advanced simultaneously, and during the juxtaposed portion of travel define a laterally closed, longitudinally extended mold cavity which moves or advances. The cavity thus defined comprises a plurality of zones corresponding to tube segments extending longitudinally in side-by-side, substantially planar disposition, with thin hinge-forming channels interconnecting adjacent segment zones. A thermosetable foam-forming resin mix is distributed on to one of the complementary mold halves prior to closing of the mold cavity. The length of travel of the conveyor in closed-mold condition is designed to permit rising and curing of the resin material, at least to a condition such that the foamed article has sufficient physical integrity to be safely handled on discharge from the mold cavity. As discharged, the integrally hinged tube segments of the molded product are in substantially flat, planar disposition. This allows for a second operation to be performed on them, if desired, such as a further molding operation to incorporate a layer of foam-forming material of different physical properties than the first. In any case, whether one or more molded layers are involved, the product has the advantage for purposes of shipping or storage space economy of being flat and stackable, yet can be readily folded by articulating the integrally hinged tube segments to form the fully closed finished tubular article. |
