Plain weave fabric is the second most widely used of the woven carbon fabrics. Plain weave is a slightly tighter weave pattern than 2/2 twill and therefore easier to handle without distorting, however it is not as drape-able as 2/2 twill and therefore it is not the first choice for compound contours.
The most commonly used weave pattern for carbon fibre is ‘2/2 Twill’. This weave pattern is looser than Plain Weave allowing the fabric to drape more easily which is especially useful when laminating into mould surfaces with compound curves and contours. The looser pattern of the weave means that it must be handled more carefully that plain weave and also that accidental distortion to the weave.
UD – Unidirectional
Unidirectional carbon fibre is a reinforcement where all (or almost all) of the carbon fibres are aligned in the same direction. The only thing holding the fibres together will be occasional strands of either carbon or polyester running across the fibres at 90 degrees. Unidirectional material is used in applications where all of the forces on a part will be in one direction (such as the body of an archery bow).