Fire resistant goods prodn. esp. cardboard, sheets, or panels - from fibres such as wood pulp mixed with water, boron minerals, and acid

摘要

The fibres are made into an aq. slurry, to which boron minerals (I) and mineral acids are added, esp. to obtain pH 1.5-3, esp. 2.0. Lhe mixt. is allowed to mature, and is then fed to a fleece mfg. and dewatering machine; the fleece obtd. is dried. Minerals (I) pref. contain Ca; and the mixt. may also contain expanded- vermiculite, -clay, -oil shale, or perlite; and/or gypsum. The water used to make the slurry is pref. recirculated, and may contain fire retardants. One fleece may be formed on top of another. In an example, to make 1 tonne of wood fibre thermal insulation panels, 643 kg disintegrated wood and/or sawdust was wet milled, and then 240 kg colemanite (45% boron) added, plus H2SO4 to give pH 2-2.5. The mixt. was left to mature, so pH 4.5-4.8 was obtd., and was diluted as required, then made into a fleece and dried to ca. 5% residual moisture. In a similar example, waste paper, sodium-cellulose, and colemanite were mixed with water and H2SO4.