Abstract: Disclosed herein is an improvement in the process for manufacturing thermal insulation panels, especially those panels used in refrigerator cabinets. The panels are composite structures which comprise a layer of a gas filled cellular insulation material combined with a layer of impact resistant thermoplastic sheet material, wherein a film of a rubber modified high nitrile polymer containing at least 45% by weight of nitrile monomer units (calculated as acrylonitrile) is interposed between the gas filled cellular material and the thermoplastic sheet. The rubber modified high nitrile polymer film presents an effective barrier to the gas in the cellular material and provides improved impact strength in the composite while retaining good rigidity of the composite structure.

Abstract: Disclosed herein is a composite structure for use in thermal insulation panels, especially those panels used in refrigerator cabinets. The composite structure comprises a layer of a gas filled cellular insulation material combined with a layer of impact resistant thermoplastic sheet material, wherein a film of a rubber modified high nitrile polymer containing at least 45% by weight of nitrile monomer units (calculated as acrylonitrile) is interposed between the gas filled cellular material and the thermoplastic sheet. The rubber modified high nitrile polymer film presents an effective barrier to the gas in the cellular material and provides improved impact strength in the composite while retaining good rigidity of the composite structure.