| abstract |
A lightweight fiber reinforced thermoplastic composite having an improved combination of surface roughness, flexural and shear characteristics. The composite generally comprises a fiber reinforced thermoplastic core containing reinforcing fibers bonded together with a first thermoplastic resin in which the core has a first surface and a second surface and at least one first skin applied to the first surface. The first skin comprises a plurality of fibers bonded together with a second thermoplastic resin, with the fibers in each first skin aligned in a unidirectional orientation within the first skin. The composite satisfies at least one of the conditions: an average surface roughness of the outer surface of the first skin is equal to or less than about 4.0 μm/10 mm; the flexural modulus and strength are greater than about 10,000 MPa and greater than about 180 MPa, respectively; and the shear modulus and strength are greater than about 3,000 MPa and greater than about 100 MPa, respectively. In another embodiment, a fiber reinforced thermoplastic composite comprises a fiber reinforced thermoplastic core containing reinforcing fibers bonded together with a first thermoplastic resin, the core having a density of about 0.1 gm/cc to about 2.25 gm/cc and a porosity greater than about 0% by volume. The core has a first surface and a second surface and at least one first skin applied to the first surface, each of the first skins comprising fibers bonded together with a second thermoplastic resin. The first skin comprises a thermoplastic melt impregnated continuous fiber prepreg material, or commingled fiber rovings comprising reinforcing fibers and thermoplastic fibers, with the fibers in the first skin aligned in a unidirectional orientation within the first skin. |