Method for forming reinforced pultruded profiles

Abstract

A method and apparatus for forming a profile that contains at least one layer of continuous fibers and at least one layer of discontinuous fibers. Said method allowing the selective control of features to achieve a profile that has increased transverse strength and flexural modulus. The layer of continuous fibers may be formed from one or more continuous fiber reinforced ribbons ('CFRT') () that contain fibers embedded within a thermoplastic polymer matrix, whereby a void fraction and in turn is minimized and flexural modulus is optimized Further, the ribbon (s) are consolidated so that the continuous fibers remain fixed in alignment in a substantially longitudinal direction (e.g., the direction of pultrusion). In addition to enhancing the tensile properties of the profile, the use of such ribbons also allows an improved handability when placing them into the desired position within the pultrusion die. The discontinuous fibers are also embedded within a thermoplastic matrix, in such a way as to assist in bonding of the layers to achieve the desired strength. At least a portion of the fibers are oriented in the transverse direction to provide increased transverse strength.