Method for making composite parts having at least one curved area

A composite part having a curved area in which undulation of filaments in the flat threads that are present in the curved area is prevented, said composite part comprising:

• a planar body with an upper surface and a lower surface that extend parallel to each other to define a thickness of said planar body, said planar body having an inner curved border which defines an inner arc having an axis that is perpendicular to the plane of said planar body and an outer curved border which defines an outer concentric arc having an axis that is perpendicular to the plane of said planar body wherein the radial distance between said inner curved border and said outer curved border defines a radial width of said planar body, said planar body comprising:
• an inner border flat thread that is located along the inner curved border of said planar body, said inner border flat thread comprising from 3,000 to 24,000 filaments selected from the group consisting of carbon fibers, glass fibers, aramid fibers, silica fibers, ceramic fibers, basalt fibers and mixtures thereof, said inner border flat thread having a length and a longitudinal axis that extends in the lengthwise direction of said inner border flat thread, said inner border flat thread having a thickness and having a width of from 1 mm to 12 mm between a first side of said inner border flat thread and a second side of said inner border flat thread, said inner border flat thread following an inner curved path along said inner curved border, said inner curved path having an inner side located closest to said inner curved border and an outer side, wherein the length of the inner side of said inner curved path along said inner curved border is shorter than the length of the outer side of said inner curved path, said inner curved path being located within the plane of said planar body and wherein said inner border flat thread has been rotated about the longitudinal axis of said inner border flat thread a sufficient number of times over the length of said inner curved path such that undulation of the filaments in said inner border flat thread is prevented;
• a flat thread that lies within the plane of said planar body in the same direction adjacent to said inner border flat thread, said flat thread being parallel to said inner border flat thread, said flat thread comprising from 3,000 to 24,000 filaments selected from the group consisting of carbon fibers, glass fibers, aramid fibers, silica fibers, ceramic fibers, basalt fibers and mixtures thereof, said flat thread having a length and a longitudinal axis that extends in the lengthwise direction of said flat thread said flat thread having a thickness and having a width of from 1 mm to 12 mm between a first side of said flat thread and a second side of said flat thread, said flat thread following a curved path adjacent to said inner border flat thread, said curved path having an inner side located closest to said inner border flat thread and an outer side, wherein the length of the inner side of said curved path is shorter than the length of the outer side of said curved path, said curved path being located within the plane of said planar body and wherein said flat thread has been rotated about the longitudinal axis of said flat thread a sufficient number of times over the length of said inner curved path such that undulation of the filaments in said flat thread is prevented;
• and
• a polymer matrix comprising an uncured resin.