Method of heating in-mold coating composition
A method of forming a polyurethane skin for an interior part of a vehicle having an in-mold coating. The in-mold coating composition is applied with an air assisted spray nozzle having an atomizing air stream that is heated to a temperature above ambient temperature. The heated air stream heats the in-mold coating composition as it is atomized and sprayed toward a forming surface by the spray nozzle. The layer of polyurethane is then applied over the in-mold coating layer to form a polyurethane skin. A heater heats compressed air before the compressed air is provided to the spray gun.
1 . A method of forming a polyurethane skin for an interior part of a vehicle, comprising:
providing an air assisted spray nozzle capable of delivering an atomizing air stream;
heating an in-mold coating composition to a temperature above ambient temperature to create a heated in-mold coating composition;
spraying the heated in-mold coating composition towards a forming surface with the air assisted spray nozzle to create an in-mold coating layer; and
applying a layer of polyurethane over the in-mold coating layer to form the polyurethane skin.
2 . The method of claim 1 wherein the step of heating the in-mold coating composition is performed by heating the atomizing air before the atomizing air is provided to the spray nozzle.
3 . The method of claim 2 wherein the atomizing air stream is heated to a temperature of between 100° F. and 200° F.
4 . The method of claim 2 wherein the atomizing air stream is heated to a temperature of between 120° F. and 160° F.
5 . The method of claim 1 wherein the step of applying the layer of polyurethane is performed by spraying a layer of aromatic polyurethane over the in-mold coating layer after a flash cycle.
6 . The method of claim 5 wherein the step of heating the in-mold coating composition is performed on the in-mold coating composition prior to entry of the in-mold coating composition into the spray nozzle, and wherein the in-mold coating is heated to a temperature of between 100° F. and 180° F.
7 . A system for manufacturing a polyurethane skin for an interior part of a vehicle, comprising:
an air compressor for providing a compressed air to an air assisted spray nozzle having an atomizing air stream;
an air heater for heating the compressed air to a temperature above ambient temperature to provide heated atomizing air;
an air assisted spray nozzle using the heated atomizing air for spraying an in-mold coating composition layer toward a forming surface of a die; and
a spray applicator for applying a layer of polyurethane over the in-mold coating layer to form the polyurethane skin.
8 . The system of claim 7 wherein the air heater heats the atomizing air stream to a temperature of between 100° F. and 200° F.
9 . The system of claim 7 wherein the air heater heats the atomizing air stream to a temperature of between 120° F. and 160° F.
10 . The system of claim 7 wherein the air heater heats the atomizing air to evaporate a solvent of the in-mold coating.
11 . The system of claim 7 wherein the spray applicator for applying a layer of polyurethane over the in-mold coating layer applies an aromatic polyurethane after a flash cycle.
12 . The system of claim 11 wherein the flash cycle is 20% shorter than a flash cycle for an in-mold coating composition applied without heating the atomization air.
13 . An in-mold coating composition spray system, comprising:
a drum containing a supply of in-mold coating composition that is connected to a fluid circuit;
a pump for pumping the in-mold coating composition from the drum and through the fluid circuit;
a spray gun connected to the fluid circuit that receives the in-mold coating composition from the pump;
an air compressor for providing compressed air through an air line to the spray gun to atomize the in-mold coating composition and direct the in-mold coating composition in a pattern; and
a heater operative to heat the compressed air in the airline before the compressed air is provided to the spray gun.
14 . The in-mold coating composition spray system of claim 13 wherein the compressed air is used to atomize the in-mold coating and also to direct the spray in a fan-shaped spray pattern.
15 . The in-mold coating composition spray system of claim 13 further comprising a color manifold station connected to the fluid circuit wherein the in-mold coating composition is selected from a group of different color in-mold coatings.
16 . The in-mold coating composition spray system of claim 13 further comprising an air piloted pressure regulator in the fluid circuit immediately up stream from the spray gun.