Appliances having sound and thermal insulation based on viscoelastic polyurethane
AssigneeDow Global Technologies LLC
InventorsGuiseppe Lista, Silvia Scussolin, Gianluca Casagrande
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Abstract
Thermal and acoustic insulation is provided to an appliance or a component thereof through a layer of a viscoelastic polyurethane foam. The selection of a viscoelastic foam of this density provides efficient thermal insulation as well as acoustic insulation.
Claims17
An appliance comprising at least one thermally and acoustically insulated component, wherein the insulated component has an insulation structure applied to at least one surface thereof, the insulation structure including at least one layer of a viscoelastic polyurethane foam having a thickness of 17 to 50 mm and an areal density of 3000 to 7500 g/m2, the viscoelastic polyurethane being characterized in that:
- a) the viscoelastic polyurethane foam has a resiliency value of at most 20% as measured according to ASTM 3574;
- b) the viscoelastic polyurethane foam has a recovery time of at least 3 seconds as measured according to ASTM D3574 Test M;
- c) the viscoelastic polyurethane foam has a lambda value of less than 0.075 W/m-° K as measured according to EN 12667;
- and
- d) the viscoelastic polyurethane foam is made in the reaction of an aromatic polyisocyanate with a mixture of isocyanate-reactive materials that includes at least 20 weight-percent, based on the combined weight of all isocyanate-reactive materials in the mixture, of at least one polyol having a molecular weight of at least 750, a hydroxyl equivalent weight of 225 to 450 and 2 to 4 hydroxyl groups per molecule, and water in an amount of at least 0.2 parts per 100 parts by weight of the mixture of isocyanate-reactive materials, wherein the isocyanate index is 60 to 100;
- wherein the appliance is a dishwasher, oven, refrigerator, freezer, clothes washing machine, clothes dryer, garbage disposal, trash compactor, vacuum cleaner or HVAC device.
A method of insulating an appliance, comprising applying an insulation structure to at least one component of the appliance, wherein the insulation structure includes at least one layer of a viscoelastic foam having a thickness of 17 to 50 mm and an areal density of 3000 to 7500 g/m2, the viscoelastic polyurethane being characterized in that:
- a) the viscoelastic polyurethane foam has a resiliency value of at most 20% as measured according to ASTM 3574;
- b) the viscoelastic polyurethane foam has a recovery time of at least 3 seconds as measured according to ASTM D3574-08 Test M;
- c) the viscoelastic polyurethane foam has a lambda value of less than 0.075 W/m-° K as measured according to EN 12667;
- and
- d) the viscoelastic polyurethane foam is made in the reaction of an aromatic polyisocyanate with a mixture of isocyanate-reactive materials that includes at least 20 weight-percent, based on the combined weight of all isocyanate-reactive materials in the mixture, of at least one polyol having a molecular weight of at least 750, a hydroxyl equivalent weight of 225 to 450 and 2 to 4 hydroxyl groups per molecule, and water in an amount of at least 0.2 parts per 100 parts by weight of the mixture of isocyanate-reactive materials, wherein the isocyanate index is 60 to 100;
- wherein the appliance is a dishwasher, oven, refrigerator, freezer, clothes washing machine, clothes dryer, garbage disposal, trash compactor, vacuum cleaner or HVAC device.
Dependencies are inferred from the claim text.