US 5,221,136 A · Refrigerator liner structures

Abstract

A refrigerator cabinet is provided with a plastic liner, the inside wall of the refrigerator, which is resistant to chemical degradation by fluorocarbons. Freon and Freon substitutes used as blowing agents for foaming the insulation contained between the outer metal cabinet and the inside wall of the refrigerator can cause blistering, cracking, and sometimes dissolution of materials used to form the plastic liner, which is the inside wall of the refrigerator. There is now provided a plastic liner which is resistant to those blowing agents and particularly to those blowing agents which are partially halogenated and tend to be more aggressive than Freon. The plastic liner wall maintains impact strength and toughness after exposure to fluorohydrocarbons conventionally employed in refrigerator units for in situ polyurethane foam production.

Claims30

Dependent claims

A refrigerator appliance cabinet which comprises an outer metal cabinet and an inner plastic liner, the improvement comprising a plastic liner molded from a thermoformable composite which comprises:

a core layer which is (1) high impact polystyrene or (2) acrylonitrilebutadient-styrene copolymer, said core layer containing 5 to 35 weight percent rubber in the form of particles having average diameters of at least 5 microns, said core layer having two surfaces;
wherein the core layer comprises at least 50 weight percent of the composite,
a gloss patina on a first of said two surfaces,
a barrier material on a second of said two surfaces of said core layer, said barrier material comprising a polymer or copolymer of ethylene or propylene containing 0 to 40% of a block copolymer rubber, based upon the weight of the barrier material, said barrier material comprising 4 to 50% by weight of the composite.

1 more element

A refrigerator appliance cabinet which comprises an outer metal cabinet, an inner plastic liner, and a polyurethane foam disposed between said outer metal cabinet and liner, wherein said foam contains a fluorinated hydrocarbon blowing agent and said liner is chemically degradable by the fluorinated hydrocarbon blowing agent, the improvement comprising:

a plastic liner molded from a thermoformable composite which comprises
a core layer which is (1) high impact polystyrene or (2) acrylonitrilebutadiene-styrene copolymer, said core layer containing 5 to 35 weight percent rubber, based on the weight of the core layer, in the form of particles having average diameters of at least 5 microns, said core layer having two surfaces;
wherein the core layer comprises at least 50 weight percent of the composite,
a gloss patina on a first of said two surfaces, which comprises less than 10 weight percent of the composite;
a barrier material on a second of said two surfaces of said core layer, said barrier material comprising a polymer or copolymer of ethylene or propylene containing 0 to 40 weight percent of a block copolymer rubber, based on the weight of the barrier material, said barrier material comprising 4 to 50% by weight of the composite and is selected from the group consisting of polypropylene, low density polyethylene, linear low density polyethylene, high density polyethylene, high molecular weight high density polyethylene.

2 more elements

Dependencies are inferred from the claim text.

Refrigerator liner structures

Life of this patent

Refrigerator liner structures

Life of this patent

Abstract

Claims30