| 摘要 |
Filter paper, e.g. for hot gases, which is mechanically strong, inert, and incombustible is formed from glass and asbestos fibres, on which is precipitated e.g. 2 to 6% of calcium silicate, as by adding a solution of sodium silicate, and calcium chloride. The glass fibres may be 2 to 6 mm long, and 1 to 6 microns in diameter. Up to 4% of polyvinyl acetate resin may be added as an emulsion. The fibre mixture may comprise 5 to 30% of Cape asbestos which may be refined on a beater before mixing in the glass fibre. Specification 945,512 is referred to. |
