Tube rolling

Tube rolling is a long-standing composites manufacturing process for producing finite-length tubes and rods. It is particularly applicable to small-diameter cylindrical or tapered tubes in lengths up to 6.1m/20 ft. Tubing diameters up to 152 mm/6 inches can be rolled efficiently. Typically, a tacky prepreg fabric or unidirectional tape is used, depending on the part. The material is precut in patterns that have been designed to achieve the requisite ply schedule and fiber architecture for the application. The pattern pieces are laid out on a flat surface and a mandrel is rolled over each one under applied pressure, which compacts and debulks the material. When rolling a tapered mandrel — for a fishing rod, as an example — only the first row of longitudinal fibers falls on the true 0° axis. To impart bending strength to the tube, the fibers must be continuously reoriented by repositioning the pattern pieces at regular intervals.