| 摘要 |
<p>The slate or scrap is milled to obtain seven fractions of (1) 8-16 mm; (2) 4-8 mm; (3) 2-4 mm; (4) 1-2 mm; (5) 0.5-1 mm; (6) 0.25-0.5 mm; and (7) 0-0.25 mm. Specific amts. of one or more of these fractions are then mixed with a synthetic resin contg. an accelerator, and a polymerisation catalyst, for max. 20 minutes to obtain max. 70 deg.C in the mixing reactor. The mixt is fed into a die vibrated at 100-150 Hz, and is compressed in the die using 40-120 bars; or two half-dies are used to compress the moulding at 40-120 bars. The visible surface of the moulding in the die is then coated with a layer of natural- and/or synthetic insulation, if required, using an adhesive to bond the layer to the moulding. Mouldings or tiles can be made, esp. from inexpensive slate scrap, which have a relatively low wt.; resist sun and other climatic conditions; and also have high strength and resist wear and corrosion.</p> |
