| 摘要 |
A prepreg comprising fibrous material impregnated with two films of an uncured thermosetting resin, comprising 15-70%, most preferably 30-40%, resin by weight of the prepreg, the prepreg having a level of impregnation given by a water pick up of from 3 to 9% (preferably 3-5%), resulting in a moulding with improved void content once cured. Preferably, the resin has a viscosity in the range of 1000-100,000Pa.s at 23°C. The fibrous material preferably comprises unidirectional filaments. The prepreg may be provided with one or more backing sheets. The resin may be a liquid epoxy resin with an Epoxy Equivalent Weight (EEW) in the range of 150-1500 and a storage modulus G of 1x106Pa to 1x107Pa. The filaments may comprise carbon, basaltic fibre, graphite, glass, metalized polymers, aramid and mixtures thereof. A process for the production of articles comprising the prepreg comprises curing at a temperature of 75-200°C, at a pressure of less than 3.0 bar absolute and preferably by an out of autoclave method such as vacuum bag. A wind turbine blade or spar made by the process is also disclosed. |
