Klosiewicz, U.S. Pat. No. 4,400,340, discloses a method of making a thermoset polydicyclopentadiene by first combining a plurality of reactant streams, one containing the activator of a metathesis-catalyst system, a second containing the catalyst of a metathesis-catalyst system and at least one containing dicyclopentadiene; then immediately injecting this combination into a mold where polymerization results in the formation of a tough, rigid thermoset polymer with high modulus and excellent impact strength.
Looman, et al., U.S. Pat. No. 3,887,728, discloses rotational molding to form molded articles using vinyl chloride-propylene copolymer. The heating and cooling times amount to 3-7 minutes each, depending on the heating and cooling system used, the wall thicknesses and the molded article and the actual mold and material of which it is made. Note column 3, lines 58-68 and column 5, lines 1 and 2. Powdered polymer is fed into the molds in the Looman, et al. process.
Takahashi, et al., U.S. Pat. No. 3,935,143 discloses feeding a mixture of polymers to a McNeil type rotating casting machine. Note column 4, lines 34-54.
Rees, U.S. Pat. No. 4,143,193, discloses a molded container made by providing a cross-linkable high density polyethylene powder in a mold which is attached to the arm of a McNeil-Akron Roto Cast rotational molding machine and transferring to an oven at 600.degree. F. (315.degree. C.), note column 4, Example 1, lines 41-46.
Looman, et al., U.S. Pat. No. 3,950,482, discloses a variation of Looman, et al., 3,887,728, as described above. Here again, a copolymer of vinyl chloride is fed to a rotational molding apparatus. In rotary molding machines, the powdered molding composition is matted upon contact with the heated mold surface. The mold can be heated by preheating circulated air, direct gas heating, low melting salt mixtures, and circulating heating bath fluids, liquids, column 4, lines 47 through 60.
Delacoste, U.S. Pat. No. 4,154,789, discloses a thermoplastic ball and method of manufacturing. In the Delacoste method, the thermoplastic is heated in a mold while imparting planetary motion to the mold.
Rotational molding is generally applicable to the molding of thermoplastic resins, and is applicable to plastic materials in the form of powder, grains or liquid. Commercial rotocasting devices are recommended by manufacturers as applicable to the molding of ABS resin as well as polyethylene, polyvinylchloride, polystyrene, nylon, cellulose butyrate, and cellulose acetate. Note Takahashi, et al., U.S. Pat. No. 3,935,143, column 1, lines 19 through 25.