Abstract: In a preferred embodiment of the present invention, a web of a corrugating medium is supplied to heated corrugating rolls to which a water mist carrying a solid lubricant as a release agent has been applied evenly over the roller, a first linerboard is glued to one side of the corrugated medium, a second linerboard is passed over a preheating roller to which a solid lubricant is applied via a water suspension sprayed on the preheating roller, the second linerboard is glued to the single faced corrugated board and the resulting double faced corrugated paperboard is passed over a hot plate section while subjected to pressure from a belt and weight roller assembly from above the hot plate.

Abstract: A process for preparing a flexible, cured sheet material, the sheet material so prepared, and in particular composition boards with the sheet material as a surface covering, which process comprises: providing a first thin fibrous sheet material impregnated with a curable thermosetting resin; placing onto one surface of the first sheet material a second flexible fibrous sheet material which is capable of absorbing an adhesive material; and subjecting the first and second sheet materials to a high pressure of over about 20 kilos per centimeter square at a thermosetting resin-curing temperature, and for a period of time to bond the surface of the second sheet material to the contacting surface of the first sheet material by the cured resin. The thin sheet material is characterized by a hard, resin-cured surface and capable of absorbing an adhesive material.

Abstract: A method of making a cylindrical electrical conductor or roving comprised of a bundle of conductive glass filaments, wherein the filaments are cured under tension in a flat ribbon-like form. The method includes binding the filaments into a preferred cylindrical bundle or roving by the steps of passing the filament bundle through the axial bore of an annular bobbin having a binder yarn or element thereon and rotating the bobbin to centrifugally throw the yarn in an unconfined balloon. The free end of the yarn is secured to the filament bundle, thereby wrapping the bundle with a helical overwrap. The balloon of yarn is controlled and stabilized by air currents generated adjacent the bobbin.

Abstract: Satisfactory or enhanced dry bond between the gypsum core of plasterboard and paper facing sheets is achieved by treatment of at least the inner faces of the paper sheets with a water soluble zirconium salt before contacting the sheets with a core slurry containing gypsum plaster and starch as a dry bond assistant. The preferred zirconium salt is zirconium acetate although other salts such as oxychloride, nitrate and sulphate can also be used. The preferred level of zirconium is from 1 to 2 g. per square meter of paper, expressed as zirconium dioxide, and excellent dry bonds are formed with as little as 0.2% starch by weight of core solids, which represents an important economy in the use of starch.

Abstract: An apparatus for manufacturing from a cassette which initially has a continuous leader extending between and connected to a pair of rotary hubs thereof and from an elongated flexible information material carrying information which can be extracted from the material a cassette which has a length of the information material stored in the cassette with opposed ends of the information material connected with leaders which are respectively connected to the rotary hubs of the cassette.