Abstract: Fiber boards of high strength which are highly water- and flame-resistant are disclosed, as well as a method for making such boards and an inorganic binder composition for bonding wood fibers. The boards comprise a lignin-containing fiber material, a binder derived from a binder composition comprising an alkali silicate solution, sulphur and/or an inorganic sulphur compound, and a calcium and/or magnesium compound and, optionally, fillers and/or hydrophobing agents.The fiber boards are manufactured by mixing the lignin-containing fiber material with the binder composition and optional further additives, whereupon the mix is compressed at a high pressure and at a temperature of 130.degree.-230.degree. C.

Abstract: A fibre board having improved strength, water-resistance and flame resistance comprises a lignin-containing fibre material and a binder. The binder is formed from a binder solution containing an alkali silicate solution, a sulphur component, and an metal component. The solution may also include hydro-foaming agents, fillers and other materials. The preferred binder solution includes 50-90 parts by weight alkai silicate solution, 0.5-10 parts by weight sulphur component and 10-40 parts by weight of the metal component. A method is also presented for the formation of an improved fibre board through utilization of a preferred mixture of a lignin-containing fibre material and a preferred binder solution under pressure, at a temperature of about 130.degree. to 230.degree. centigrade.

Abstract: A molding mixture comprising a filler, such as wood particles and a resin binder, is pressed under light pressure on a flat bed to produce a mat with a density between 1/15 and 1/3 of the material in the finished article to be made by pressure molding. A molding preform is then made from a piece of such mat having a suitable contour, by sculpturing one side of the mat with suction devices to provide a thickness variation over the mat area corresponding to the requirements of the molding step.

Abstract: A method of and apparatus for the manufacturing of products of plastic to which a filler preferably of wood material has been added to a high degree as described. A thermosetting or otherwise solidifying plastic compound has finely divided filling material distributed therein so that a mixture is obtained. The mixture is introduced into a mold and is pressed by a ram adapted to the shape of the product. The mixture in the mold is subjected to vibrations of a special form provided from synchronized vibrations.