Processes for making molded composite panels

A one-step molding process for the production of a composite panel of variable thickness comprising a fiber backing and a cover sheet, said panel having at least one area of greater thickness and one area of lesser thickness, said process comprising the steps of:

• placing a stratified assembly comprising a first layer of fibers and a non-polymerized binder and a second layer comprising a cover sheet thereover between a mold and mold backing which are mutually shaped to define said areas of greater and lesser thickness;
• conforming said stratified assembly to the shape of said mold or mold backing by pressurization of the mold defined thereby, said pressurization being effected by forcing air into the mold while preventing exhaust thereof thereafter, blowing heated air by partial crossover blowing into the assembly only in the area corresponding to said area of greater thickness, said air being blown into said assembly from the side opposite said cover sheet, and escaping on the same side,
• thereafter reversing the direction of said blown air with the air inlets in the first blowing phase becoming the air outlets of said reverse blowing phase, said blowing being maintained for sufficient time and at sufficient temperature to polymerize said binder, and
• contact heating the areas of said assembly corresponding to said area of lesser thickness.