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US 4,515,646 AGranted
Method for applying polyurethane backing
AssigneesPaul Walker, Glen F. Hamrick
InventorsPaul Walker, Glen F. Hamrick, B. Lamar Sosebee
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AssigneesPaul Walker, Glen F. Hamrick
InventorsPaul Walker, Glen F. Hamrick, B. Lamar Sosebee
Estimating the term…
A method for applying a blown polyurethane coating to carpeting or other sheet material. The method includes the step of adding a filler to the polyurethane components to assure that the liquid does not unduly penetrate porous goods. The mixed polyurethane components are then placed in a puddle on the sheet material and leveled to a uniform coating. Steam is passed through the sheet material and the coating to initiate the reaction of the components. The steam also adds water to the coating, so the formulation is such that additional water is needed, and the needed water is added by the steaming. After the polyurethane has completed blowing, and before the polyurethane has cured beyond its plastic state, the foam may be compressed to decrease the thickness. A second sheet of material can be placed over the polyurethane to prevent the polyurethane from adhering to the compressing roller.
A method for forming a blown polyurethane coating on porous sheet material, said polyurethane coating being formed by reaction of urethane forming components including at least a polyol, an isocyanate and water, said reaction requiring heat for initiation, said method including the steps of cooling said components to a temperature substantially below the temperature for initiation of the reaction, preparing a formulation of said urethane forming components having an excess of the isocyanate relative to the water compared to the desired coating formulation to provide a liquid mix, placing a quantity of said liquid mix on said porous sheet material in a puddle, leveling said puddle to provide a uniform coating of said liquid mix on said porous sheet material, passing steam through said sheet material and into said uniform coating for adding water to said liquid mix for reaction with said excess of isocyanate and for heating said liquid mix to start said reaction.
Dependencies are inferred from the claim text.