| 摘要 |
1,158,460. Timber substitutes. W. R. GRACE & Co. 20 June, 1967 [1 July, 1966], No. 28465/67. Headings C3C, C3N and C3R. A building board comprises a blend of wood particles, unexpanded, expandable mineral ore, e.g. vermiculite or perlite, and a binder, and integral therewith on at least one side a layer or layers of compressed exfoliated vermiculite or unexpanded vermiculite ore. There may be a second layer, integral with the first, of exfoliated vermiculite. The board may be made by spreading in the bottom half of a press: (a) a mixture of exfoliated vermiculate and synthetic resin; and on this layer spreading (b) a mattress of wood chips, unexpanded vermiculite, and synthetic resin binder; and on this layer a futher layer of (a), and hot-pressing. The assembly may be cold-pressed before hot-pressing. The wood particles may be chips, flakes, shavings, splinters, or sawdust. The wood may have moisture content 7À2%. In (b) there may be 10-80 wt. per cent vermiculite based on wood. The binder may be ureaformaldehyde, phenol-formaldehyde, or melamine-formaldehyde. Paraffin-based wax emulsions may also be added. In a contrasting example (b) contains no vermiculite. |
