Compression molding method and reinforced thermoplastic parts molded thereby

A method of molding a fiber reinforced composite part, comprising:

• cutting a plurality of flakes from a unidirectional fiber preform pre-impregnated with a thermoplastic resin, the plurality of flakes including flakes of at least two different shapes respectively having fibers of differing lengths, the flakes of the at least two different shapes being mixed together;
• forming a mold charge by introducing a preselected quantity of the plurality of flakes into a mold;
• and
• compression molding the mold charge in a mold cavity, the compression molding including compressing the mold charge at a rate that results in turbulent flow of the mold charge through the mold.

A method of making a part, comprising:

• cutting a plurality of first flakes from a first unidirectional carbon fiber thermoplastic prepreg tape, each of the plurality of first flakes having a first shape;
• cutting a plurality of second flakes from a second unidirectional carbon fiber thermoplastic prepreg tape, each of the plurality of second flakes having a second shape different than the first shape;
• mixing the plurality of first flakes and the plurality of second flakes into a mold charge having a mold cavity substantially conforming to a shape of the part;
• and
• compression molding the mold charge, including applying heat and pressure to the mold charge that results in a turbulent flow of the mold charge through the mold cavity, such that the combination of the flow rate and a viscosity of the mold charge results in the fibers in the plurality of first flakes and the plurality of second flakes being distributed substantially uniformly through the mold cavity with substantially random fiber orientations.