| 摘要 |
<p>Raw paper-board (I) comprises org. fibres (II) mixed with 20-70 (55)% diabase wool (III), and a binder (IV). (II) comprises rags, chem. pulp, or a mixture thereof. (III) contains 16-17% Al2O3, 11% FeO+Fe2O3 and 2% alkali. (IV) is a mixture of carbamide-resin and starch, this having a high affinity for (III). Sheets of pure (III) have been used for wall etc., insulation but they are relatively brittle and only really useable for the insulation of supporting walls, etc. Mixed with (II), however, together with (IV), such sheets can be used as roofing felt having good dimensional stability due to (III), and good strength due to (II) present which makes the product resistant to mech. stress.</p> |
