Brunswick Corporation

Stephen Crane

Charlie Reeves

Dave Gruenwald

A thermoplastic multi-layer composite structure is disclosed and consist in a first embodiment of a co-extruded acrylic polypropylene outer skin and high melt strength polypropylene substrate which is attached to a first surface of a polypropylene foam core. An inner polypropylene skin can be provided and is attached to a second surface of the foam core. The foam core can either be constructed from an expanded polypropylene or an extruded polypropylene. Where an expanded polypropylene foam core is provided, the foam core is attached to the outer and inner skin through the use of a polypropylene adhesive. Where the extruded polypropylene foam core is provided, the skins can be attached to the foam core through a welding or bonding process in lieu of adhesives. The polypropylene adhesives can also be utilized for attaching the skins to the extruded foam core. Additionally, the extruded foam core can vary in density to provide a composite foam core. Preferably, the various densities of the composite foam core are arranged such that the lowest density foam is provided at the center of the core and the varying densities of the foam core extend outward from the center in numerical order. In an alternative embodiment, an all acrylic composite multi-layered structure is provided.

Thermoplastic multi-layer composite structure

A thermoplastic multi-layer composite structure is disclosed and in a first embodiment as a co-extruded acrylic polypropylene outer skin and high melt strength polypropylene substrate which is attracted to a first surface of a polypropylene foam core. An inner polypropylene skin is attached to a second surface of the foamed core, which can either be constructed from an expanded polypropylene or an extruded polypropylene and is attached to the outer and inner skin through the use of an adhesive. Where an extruded polypropylene foam core is provided, the skins can be attached to the foam core by adhesives or through a welding or bonding process in lieu of adhesives. Additionally, the extruded foam core can vary in density to provide a composite foam core. An all acrylic composite multi-layered structure is also provided.

A thermoplastic multi-layer composite structure is disclosed and consist in a first embodiment of a co-extruded, acrylic polypropylene outer skin and high melt strength polypropylene substrate which is attached to a first surface of a polypropylene foam core. An inner polypropylene skin can be provided and is attached to a second surface of the foam core. The foam core can either be constructed from an expanded polypropylene or an extruded polypropylene. Where an expanded polypropylene foam core is provided, the foam core is attached to the outer and inner skin through the use of a polypropylene adhesive. Where the extruded polypropylene foam core is provided, the skins can be attached to the foam core through a welding or bonding process in lieu of adhesives. The polypropylene adhesives can also be utilized for attaching the skins to the extruded foam core. Additionally, the extruded foam core can vary in density to provide a composite foam core. Preferably, the various densities of the composite foam core are arranged such that the lowest density foam is provided at the center of the core and the varying densities of the foam core extend outward from the center in numerical order.

A rotational molding method is provided consisting in a first method of spraying the inner mold area with an acrylic polyethylene alloy prior to loading the resin into the mold. The mold is then heated, rotated and cooled to form the molded part. The part is provided with a shinier and harder surface layer as compared to previous rotational molding methods. In a second method, in lieu of spraying, the acrylic polyethylene alloy is loaded into the mold with the resin. In the third and fourth methods, a drop box is provided for releasing resins into the mold. Other materials, in addition to acrylic polyethylene, can also be used with the various methods.

Rotational molding process

A thermoplastic multi-layer composite structure is disclosed and consist in a first embodiment of a co-extruded acrylic polypropylene outer skin and high melt strength polypropylene substrate which is attached to a first surface of a polypropylene foam core. An inner polypropylene skin can be provided and is attached to a second surface of the foam core. The foam core can either be constructed from an expanded polypropylene or an extruded polypropylene. Where an expanded polypropylene foam core is provided, the foam core is attached to the outer and inner skin through the use of a polypropylene adhesive. Where the extruded polypropylene foam core is provided, the skins can be attached to the foam core through a welding or bonding process in lieu of adhesives. The polypropylene adhesives can also be utilized for attaching the skins to the extruded foam core. Additionally, the extruded foam core can vary in density to provide a composite foam core. Preferably, the various densities of the composite foam core are arranged such that the lowest density foam is provided at the center of the core and the varying densities of the foam core extend outward from the center in numerical order.

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Stanwood, WA, United States of America

Stephen Crane