Method for forming a layer of blown cellular urethane on a carpet backing
OwnerJohn G. Tillotsoninventor
Life of this patent
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Abstract
A method of forming a layer of blown cellular urethane on a primary carpet backing comprising the steps of preparing a mixture of reactive urethane forming agents, controlling the temperature of the reactive mixture, shaping the reactive mixture into a layer upon a latex film, heating the urethane forming mixture to initiate chemical blowing of the mixture, applying the underside of a previously tufted and heated primary carpet backing directly to the upper surface of the mixture, heating the mixture to a predetermined temperature, applying pressure to the carpet and mixture and stripping the carpet and cellular urethane from the conveyor belt.
Claims3
Method for producing a layer of flexible chemically blown urethane foam cushion having a density of between one and ten pounds per cubic foot on the back of a carpet product, in which a mixture of reactive urethane forming components, including isocyanate and polyol, is prepared, the mixture is depositioned on a carrier belt, the back of a preheated carpet product is brought into contact with the mixture, and the mixture which is in contact with the carpet back is chemically blown in a heated urethane foaming station into an enlarged layer of cellular urethane and cured under the effect of heat, comprising the steps of:
- (1) mixing the reactive components together in a traversing mixer at a temperature of between 60.degree. and 100.degree. F. and dispensing the mixed components onto an endless carrier belt which has been cooled to a temperature of between 50.degree. and 100.degree. F., said reactive components including water at a concentration of 0.01 to 5.0 parts per hundred parts of polyol over and above the water normally present in the reaction mixture and a catalyst which will promote a polyurethane formation reaction and concurrently promote a chemical blowing reaction so that an expansion of between 500 percent and 6400 percent is obtained for the polyurethane material;
- (2) partially reacting the mixed components on the carrier belt by heating the mixed components to a temperature of between 90.degree. and 150.degree. F.;
- (3) preheating the lower surface of an uncoated carpet material to a temperature of between 100.degree. and 300.degree. F.;
- (4) bring the lower surface of the preheated carpet material into flush contact with the partially reacted urethane component mixture;
- (5) passing the carrier belt, with its urethane mixture, and the carpet material through a urethane forming station at the same speed;
- (6) heating the urethane mixture to a temperature of between 120.degree. and 200.degree. F. in the urethane forming station for a period of 15 seconds to 120 seconds and permitting upward movement of the carpet material as the reactive urethane mixture chemically blows during urethane formation;
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- (7) curing the blown urethane foam by heating the foam to a temperature of between 150.degree. and 350.degree. F.
Dependencies are inferred from the claim text.