Patent ID: 8088470

Claim:
A preform moulding material comprising: two individual unidirectional reinforcement layers of a fibrous reinforcement material; and a resin material between adjacent ones of the fibrous reinforcement layers; wherein the resin material is a matrix resin material, whereby the preform moulding material forms a prepreg; wherein the matrix resin material between the fibrous reinforcement layers partially impregnates and conjoins the fibrous reinforcement layers, thereby obviating the need in the prepreg for an additional bonding means to join the individual fibrous reinforcement layers; wherein one of the fibrous reinforcement layers includes a fabric that is skewed relative to a lengthwise direction of the preform moulding material and including a weft of unidirectional fibrous reinforcement material disposed at an angle relative to the lengthwise direction and a warp of fibres in the lengthwise direction; and wherein the other of the fibrous reinforcement layers includes a fabric that is skewed relative to the lengthwise direction of the preform moulding material and including a weft of unidirectional fibrous reinforcement material at an angle relative to the lengthwise direction and a warp of fibres in the lengthwise direction; wherein the orientation of the unidirectional fibrous reinforcement material of one of the reinforcement layers differs from the orientation of the unidirectional fibrous reinforcement material of the other reinforcement layer; whereby said preform moulding material is bi-axial prepreg.