Abstract: A machine and method are disclosed whereby multiple casting units simultaneously produce foamed-plastic tubular articles which may be of different shapes and sizes. All units are served from a single supply of foamable material, and in each unit rotation of an annular mold develops a homogenous longitudinal and radial distribution of foaming plastic. The foaming plastic is introduced into each mold rotation, the cavity being closed to permit foamed filling of the mold, and a polymerizing cure is effected prior to mold opening and product removal. The particular machine herein described includes provision for coordinated shot size for foamable material into each of the plural mold cavities, whereby regardless of the mold-cavity size at particular casting units, the shot size (of foamable plastic material) is automatically determined, for uniform or predetermined density in the ultimate products regardless of size variation produced at the respective casting units.

Abstract: The invention contemplates a machine and method whereby rotation of an annular mold is used to develop a homogenous longitudinal and radial distribution of foaming plastic. The foaming plastic is introduced into the mold cavity during mold rotation and, particularly where mold-cavity length substantially exceeds mold-cavity diameter, a longitudinal traverse is imparted to the introduction of foaming material during rotation of the mold. The cavity is closed to permit foamed filling of the mold, and a polymerizing cure is effected prior to mold opening and product removal. The particular machine herein described is notable (a) for its ready mechanical release from both inner and outer molding contact with the product, (b) for its inherent adaptability to production of a selected one of a plurality of inner and outer profiles and sizes in the product, and (c) for its safe accommodation of fast-foaming and curing plastics, even for relatively large product diameter or girth.