| 摘要 |
Fibre reinforced resin products are produced by distributing a thermosetting resin powder in or on a felt and then placing the felt in a moulding press heated to the curing temperature of the resin, the press being repeatedly opened and closed to cause the fusion of the resin and its distribution throughout the felt and then to cure it. Corrugated plates, for example, are formed by first depositing, using a vibratory sprinkler, a uniform layer of 750g/m2 of a powdered phenol formaldehyde resin on a strip of needled jute felt. A second identical felt is placed on top and the two are passed, to become seni-rigid, through two calender rolls heated to 120 DEG C. The strip is cut into plates and two of them, separated by a metal sheet or non adhesive film, are put in a press capable of exerting a pressure of 1800 tons and provided with two corrugated mould members heated to 165 DEG C. After three cycles each of a 15 second closure followed by a 5 second opening there is a fourth closure of 45 seconds. The method may be modified for other objects, i.e. motor housings, by passing the felt on a conveyer under a resin distributer, and the calendering process may be replaced by using a press or may be omitted. The pressure in the fibre of some water, say 3-6% per weight of the fibre as a minimum is advisable. The felt may have been impregnated with the resin before it was needled. |
