| 摘要 |
<p>An aq. mixt. of plaster contg. fibrous material for reinforcement is subjected to vibration prior to the casting and drying of finishing laminates. The mixt. is subjected to a range of vibrations from 1,000 vibrations per min.-1 to a rate which is beneath that at which the mixt. contg. plaster separates out. The vibratory treatment is pref. carried out at 3,000-4,000 vibrations per min.-1. The starting mixt. contains 50wt.% of plaster. The cement is a metal slag cement and/or an aluminium cement with a BLAME fineness of 5,000 cm2/g. The reinforcement is pref. glass fibre mat. Plaster mixt. impregnated, fibre reinforced laminates are produced in a much shorter time than is necessary when woven fibre sheets are used. In addn., the prodn. costs are reduced and laminates are produced with a smooth rear face.</p> |
