Method for forming a sheet, fiber and resin composite

A method of forming a finished composite part comprising:

• providing a mold, the mold defining a cavity with a shape-defining surface, the mold having a shear edge, the shear edge having an upper surface, having a lower surface spaced from the upper surface, defining an interior portion between the lower surface and the upper surface where the part is to be formed, and having an exterior portion between the lower and upper surface configured to remain free of the paint sheet and the resin and fiber mixture during molding, wherein an interior portion is configured to contain the paint sheet and the mixture of resin and fiber and an exterior portion of the mold shear edge is configured to operate with a spacing between the upper surface and the lower surface to allow evolved gasses to escape;
• providing an in-mold paint sheet having a thickness of greater than about one millimeter, the in-mold paint sheet having a bonding side and a finish side;
• installing the in-mold paint sheet in the cavity of the mold by preforming the paint sheet to the mold so that that the finish side of the in-mold paint sheet is conformed adjacent to the shape-defining surface of the mold;
• introducing a mixture of a polyurethane thermoset resin and a plurality of carbon reinforcing fibers with a length of about 25 millimeters by impelling uncoated carbon reinforcing fiber towards the mold cavity so that the resin substantially completely wets substantially all of the reinforcing fibers prior to the introduction of the fiber and resin mixture into the cavity and so that the resin and fiber mixture contacts the bonding side of the in-mold paint sheet;
• enclosing the in-mold paint sheet and resin and fiber mixture in the mold;
• heating the resin and fiber mixture wherein the resin expands in the mold as it cures;
• and
• cooling the paint sheet to a temperature of about 70° F. to 150° F., wherein the resin and fiber mixture is cured and bonded to the in-mold paint sheet in a one-shot process to form a one piece assembly having the finish side of the in-mold paint sheet as a finished Class A surface of the part.