BUILDING BOARD

摘要

1404001 Building board compositions CAPE UNIVERSAL BUILDING PRODUCTS Ltd 8 June 1973 [8 March 1972] 10741/72 Heading D2B An asbestos free composition for use in the manufacture of a fire-resistant building board comprises a water-settable inorganic binder which is one or more of a calcium silicate binder, Portland cement, aluminous cement, blast furnace slag cement or compounds necessary for the formation of a calcium silicate binder, a fibrous reinforcing material which includes organic fibres do not melt below 140‹C and vermiculite. In addition inorganic fibrous reinforcing material may be added. Some or all of the fibrous material may be coated, with, for example alkali-resistant material. Other filler materials may also be incorporated in the composition. The aqueous slurry from which a building board is produced has a solids content of 3-20% by weight, and is slightly heated to 25-35‹C and may contain flocculants and filtration aids, e.g. polyacrylamides, water retention aids, hydro modifiers, (e.g. carboxymethyl cellulose derivatives, polyethylene oxides), wetting agents (e.g. detergents), and setting controlling agents (e.g. calcium chloride and ligno sulphates). The board is then formed from the slurry by the Hatchek, Magnani, or Fourdrinier process or by a simple press. The organic fibres may be cellulosic fibres, for example, sulphate, sulphite, and mechanical fibres, waste wood pulps, jute, flax, cotton, straw, esparto grass, hemp, rannie and bagasse. Other possibilities include polyamide fibres, e.g. Nylon, polyester fibres, e.g. polyethylene terephthalate, polypropylene, carbon and viscose fibres. The inorganic fibres may be mineral wool fibres such as glass fibres, slag wool fibres, rock wool fibres, ceramic fibres such as zirconium oxide and aluminium fibres, silicaalumina fibres, aluminium silicate fibres and metal fibres. These additional fibres may constitute 0.5-60% by weight of the total fibrous material. The inorganic binder may be a calcium silicate binder, Portland cement, aluminous cement, blast furnace cement or refractory cement. Calcium silicate binders are preferred especially those having a tobermorite or xonotlite crystal structure. The binder comprises 50-95% by weight of the total weight of the binder and reinforcing fibre. The fillers may be perlite, mica, kieselguhr, clays and clay wastes, carbonates such as chalk, dolomites and magnesium carbonate, wollastonite and other calcium silicate fillers.