TABLE OF CONTENTS Glass fibres have been known in one form or another since 1500 BC, and some glass fabrics have been produced as far back as the beginning of the eighteenth century, but all of these were far too coarse to be of any industrial value. During the late 1930s glass fibre became available on a commercial scale and of a quality and smallness of diameter which enabled it to be manufactured into textile products. This was due to the development of the continuous filament process. It was soon apparent that the fibres made by this new process had many desirable properties such as strength, smallness of diameter, high elasticity, and the ability to withstand high temperatures.
Early attempts to use glass fibre as a reinforcement were disappointing. The resin then being used required high moulding pressures and this led to a crushing of the fibres with a resulting loss in strength. During the early 1940s an entirely new group of resins was introduced; these were known as contact resins as they could be used without pressure. Of the contact resins the polyesters are undoubtedly the best known, and they are the most widely used resins in the preparation of glass reinforced laminates because of their combination of low cost and ability to be moulded without pressure, and because their conditions of use fitted into normal workshop practice. With glass fibre as a reinforcement they could be used by relatively unskilled labour to produce strong, lightweight...
