Unidirectional Carbon Fiber Fabric

Unidirectional fabric has 95%+ of fibers oriented in a single direction (0°). Woven fabric has fibers in both 0° and 90° directions. UD fabric provides much higher stiffness and strength in the fiber direction but requires cross-plying for multi-axial loads. Woven fabric offers balanced properties but lower stiffness in any one direction.

Yes. UD fabric should be cross-plied with layers oriented at 0°, 90°, and ±45° to create balanced laminates. For uniaxial load applications (e.g., spar caps), all plies can be oriented in the same direction for maximum efficiency.

The binder (thermoplastic powder or cross-weave) holds the fibers in position during handling and layup. It dissolves into the resin during cure and does not affect mechanical properties. The binder content is typically 3% – 6% by weight.

Yes. UD fabric is well-suited for vacuum infusion. However, the tightly packed tows require lower viscosity resins (≤ 200 cP) and slightly lower injection pressure (0.3–0.5 bar) for complete wet-out. Using flow media on both sides of the fabric improves infiltration.

With vacuum bagging: 55% – 58%. With autoclave or compression molding: 60% – 65%. The high fiber alignment allows excellent compaction without fiber distortion, achieving some of the highest Vf values of any carbon fabric form.