A screw smelting machine melts raw materials with a different chemical ratio in a mixing funnel in a feeding order to prevent the long-range diffusion of a melt, and controls outflow at a suitable speed. A centrifugal casting machine solidifies the melt with the ingredients gradient varying into a radial ingredient gradient material by a centrifugal casting style. A temperature sensor monitors temperature of an outer surface of a centrifuge cavity of the centrifugal casting machine during centrifugal casting, and transmits the temperature to a control platform. The control platform determines an optimal flow rate of the melt at an end of screw rod according to ingredient gradient of ingredient radial-gradient pipe materials and a thickness of each component gradient material required with preparation, in combination with a real-time data fed back from the temperature sensor, and feeds back to a feeding end.

A screw smelting machine melts raw materials with a different chemical ratio in a mixing funnel in a feeding order to prevent the long-range diffusion of a melt, and controls outflow at a suitable speed. A centrifugal casting machine solidifies the melt with the ingredients gradient varying into a radial ingredient gradient material by a centrifugal casting style. A temperature sensor monitors temperature of an outer surface of a centrifuge cavity of the centrifugal casting machine during centrifugal casting, and transmits the temperature to a control platform. The control platform determines an optimal flow rate of the melt at an end of screw rod according to ingredient gradient of ingredient radial-gradient pipe materials and a thickness of each component gradient material required with preparation, in combination with a real-time data fed back from the temperature sensor, and feeds back to a feeding end.

Compositions may include a polymer melt blend composition prepared from two polyethylene copolymers having different densities, wherein the polymer melt blend composition possesses improved flowability and impact resistance for low thickness rotomolding applications. Low thickness articles may include a polymer melt blend composition prepared from two polyethylene copolymers having different densities, wherein the articles possess improved finishing properties. Rotomolding processes may include melt blending from two polyethylene copolymers having different densities, pulverizing the melt blend, and rotational molding the composition thereof.

Compositions may include a polymer melt blend composition prepared from two polyethylene copolymers having different densities, wherein the polymer melt blend composition possesses improved flowability and impact resistance for low thickness rotomolding applications. Low thickness articles may include a polymer melt blend composition prepared from two polyethylene copolymers having different densities, wherein the articles possess improved finishing properties. Rotomolding processes may include melt blending from two polyethylene copolymers having different densities, pulverizing the melt blend, and rotational molding the composition thereof.

A pallet assembly includes a support assembly and a base assembly. The support assembly has a deck molded from a plastic shell material and male fittings that extend away from a lower surface of said deck. The base assembly includes a stringer that defines a plurality of openings which extend through the entirety of the stringer. A female fitting extends completely through each of the openings in the stringer so that the base of each of the female fittings is flush with or extends beyond the bottom surface of said stringer. Each of the male fittings corresponds to a female fitting, attaching said support assembly to said base assembly.

A method of manufacturing a spa including molding a plurality of side walls, cutting utility openings in said side walls, thereby producing cutouts which are then secured to the side wall and cover at least a part of the utility opening. The cutouts may cover the same utility opening from which it stems or a different utility opening from the same side wall or different side wall. The side walls may be made integral to the basin, such as in rotomolded spas, or made separate from the basin. Certain cutouts are rotated so as to have a major dimension of the cutout cover a minor dimension of the utility opening. Certain cutouts are trimmed from their initial size so as to cover a utility opening smaller than the utility opening from which it stems.

A method of manufacturing a spa including molding a plurality of side walls, cutting utility openings in said side walls, thereby producing cutouts which are then secured to the side wall and cover at least a part of the utility opening. The cutouts may cover the same utility opening from which it stems or a different utility opening from the same side wall or different side wall. The side walls may be made integral to the basin, such as in rotomolded spas, or made separate from the basin. Certain cutouts are rotated so as to have a major dimension of the cutout cover a minor dimension of the utility opening. Certain cutouts are trimmed from their initial size so as to cover a utility opening smaller than the utility opening from which it stems.

A method for continuously producing a composite material is disclosed. In some implementations, the method includes supplying a thermoplastic resin having an initial density, mixing polypropylene-graft-maleic anhydride (PPgMA) formed of a plurality of interconnected PPgMA molecules throughout the thermoplastic resin, distributing a plurality of carbon particles throughout the thermoplastic resin and the plurality of interconnected PPgMA molecules, and forming, by rotational molding, the composite material based on a combination of the thermoplastic resin, the PPgMA, and at least some of the plurality of carbon particles.

A method for continuously producing a composite material is disclosed. In some implementations, the method includes supplying a thermoplastic resin having an initial density, mixing polypropylene-graft-maleic anhydride (PPgMA) formed of a plurality of interconnected PPgMA molecules throughout the thermoplastic resin, distributing a plurality of carbon particles throughout the thermoplastic resin and the plurality of interconnected PPgMA molecules, and forming, by rotational molding, the composite material based on a combination of the thermoplastic resin, the PPgMA, and at least some of the plurality of carbon particles.

Compositions for forming rotationally molded (rotomolded) parts, methods for forming the rotomolded parts, and the rotomolded parts are provided. An exemplary rotomolding composition includes a virgin resin, including a polyethylene polymer, and a postconsumer recycle (PCR) resin.