Uni-Directional Vs. Woven
Strength and Weight
All the strength in fiber composites is gained through the fibers and the fiber direction. As a result, you can dictate a part’s strength by the direction you place the fibers.
If Part B requires 70% strength in the A to B direction and 30% strength in the C to D direction, then the uni-directional fiber angles would match those requirements. While woven fiber would waste 40% additional material to meet the same requirements.
The enormous advantage of uni-directional fiber is it allows you to customize the fiber direction to the strengths you require, therefore minimizing waste material, costs, and weight. The ability to customize your fiber direction allows you to only use as much material and fiber as you need; rather than waste material, costs, strength, and weight in directions you don’t.
On a pure performance basis, there is NOTHING stronger than a uni-directional fiber layup.
Traditional woven fiber products are limited to two angles, 0deg and 90deg (perpendicular). Uni-directional fiber placement eliminates that limitation. Fibers can be set at any angle, therefore improving the performance of your part. Few products require the same amount of fibers running perpendicular to each other; as a result, woven cloth tends to produce heavier products with lower performance.
Carbon fiber is most commonly known by the traditional “weave” look of woven cloth. While in some ways it is an attractive external appearance, composite parts are usually more concerned with performance than appearance. As a result, the market and perception of composites is changing, and in the end, performance improvements will drive the material. Today companies are beginning to advertise uni-directional fiber in contrast to a “weave” look.