Abstract: A gypsum board comprises linings made of coated non-woven fiberglass mats having surfaces turned away from the gypsum core of the fiberglass mats which have been coated with an inorganic binder at least partially set with water. Preferably, quick-setting mixtures comprising cement, .alpha.-hemihydrate and ultra-fine silica are used which are dimensionally stable during setting as well as later on.

Abstract: A fiberglass product usable as an end product or an intermediate product is formed as a pack in a forming station but only 1/7th of the conventional quantity of binder is applied. After curing to a self-sustaining form, additional binder is added at a location remote from the forming station in an amount in excess of the amount required in the final product and then the excess binder and moisture is removed by one or more vacuum stripping steps.

Abstract: A process for using shredded scrap or virgin fiber glass in combination with starch, water and other components to make ceiling tiles. The tiles are made by initially preparing a mixture of water, starch, boric acid and fire clay. That initial mixture is then heated to form a gel. Fiber glass is then added to the gel to form a pulp. The pulp is fed into trays to form slabs. The slabs are dried and finished into tiles.

Abstract: The process for preparing calcium sulfate anhydrite II by heating a flowable powder of flue gas gypsum moistened with less than 20% by weight, and preferably with from 7 to 17% by weight, of diluted sulfuric acid, wherein the sulfuric acid content is from 0.5 to 7% by weight, and preferably 1 to 3% by weight of sulfuric acid, based on the total mixture, is carried out by that the total mixture is direct-fired or is rapidly heated with indirect heat exchangers having relatively high wall temperatures whereby it is heated at temperatures of from 80.degree. C. to 190.degree. C. and releases the water adherent from the diluted sulfuric acid as well as two moles of water of crystallization, and then the virtually anhydrous product is annealed at temperatures of from 80.degree. C. to 190.degree. C. for 0.3 to 24 hours.

Abstract: A process for consistently making ceiling tiles having uniform density and surface texture includes using a conveyor along which trays are moved in a generally horizontal direction. A feeder box is used to deposit pulp in the trays, the pulp being comprised of a mixture of water, starch, fibrous material, and other ingredients. The feeder box through which pulp is deposited in the trays is of a special design, and includes a sloping front edge which creates a negative rake angle with respect to layers produced by the system. The lower front edge of the feeder box includes a surface having a compound curvature. Ceiling tiles are produced by the process having improved uniformity of density and surface texture.

Abstract: A lateral varactor is fabricated with a recess structure that provides staggered punch-through points, enabling the varactor to be tuned through punch-through without significant non-linearities in either capacitance or Q. The lateral varactor (30) includes a cathode (32) and an anode (40) disposed on the surface of an active layer (12). The anode (40) includes a surface section (45), and a recess section (46) disposed within a recess area (50). This recess structure results in a greater active layer depth under the anode surface section (45) than under the anode recess section (46). As a result, as reverse-bias voltage on the anode increases, the depletion region (60) reaches punch-through under the anode recess section (46) prior to reaching punch-through under the anode surface section (45).

Abstract: The invention relates to a method of producing an adsorbent where an expanded granular bloating mineral and calcium sulfate hemihydrate are mixed to form a granulated material where the calcium sulfate hemihydrate is converted in toto into calcium sulfate dihydrate by the addition of a surplus of water, and where the free water is removed by drying. It is desirable that the proportion of bloating mineral be reduced, that the adsorption effect be substantially retained and the hardness of the adsorbent be increased without any additives.

Abstract: This invention relates to a pipe insulation product which, as contrasted to presently available commercial products, eliminates fishmouthing of the protective liner from the insulation blanket, eliminates cutting the liner at the job, always a difficult task, is extremely easy to manufacture, ship and handle, and is very easy to use in the field, even under adverse working conditions such as high winds.

Abstract: The invention concerns a gypsum construction board in which a gypsum core is faced with a two-layer laminate comprised of a nonwoven fiber felt and a glass fiber web of crossed glass fibers wherein the glass fiber web of crossed glass fibers is embedded in the gypsum core and the laminate is in the form of a laminate sheet which extends across the width of the board.

Abstract: A method and apparatus for purifying waste product emissions from the manufacture of glass fiber products, including a system in which an electrostatic precipitation may or may not be employed, and in which separate, and easily controlled, forming air and oven air scrubbing systems are employed.

Abstract: Fiber containing plaster boards are prepared by superimposing a plurality of board blanks one on top of the other such that the direction of the fiber orientation in the superimposed blanks deviates one from the other. The board blanks are formed in a conventional manner from a suspension of calcium sulfate capable of setting, reinforcing fibers and a quantity of water beyond the quantity of water necessary for setting the calcium sulfate capable of setting. After mechanically removing excess water from the suspension to form the board blanks, two or more of these blanks are placed one on top of the other and are connected under pressure and dried. Thereafter, a predetermined number of board blanks having a direction of the fiber orientation deviating one from the other, are placed one on top of the other and are pressed together prior to or during the setting of the calcium sulfate.

Abstract: Pelletized calcium sulfate is prepared from finely divided, natural or synthetic calcium sulfate, wherein the particle size of the finely divided calcium sulfate is at least about 90 per cent by weight less than 200 .mu.m, there being no particles larger than 500 .mu.m, and wherein the finely divided calcium sulfate has a free water content of from about 0.5 to about 4 per cent by weight, by pressing the finely divided calcium sulfate in the presence of water with a roll press using a surface pressure of 1 to 5 Mp per cm roller length.

Abstract: Calcium sulphate produced by reacting crude phosphate with sulphuric acid is washed with aqueous solutions of condensed and complex aluminium fluorides of the general formulae MeAlF.sub.4, Me.sub.2 AlF.sub.5 and Me.sub.5 Al.sub.3 F.sub.14 as well as AlF.sub.3.nH.sub.2 O, in which Me represents an alkali metal, ammonium or thallium-I ion and n is a number between 1 and 9.

Abstract: A multi-layered gypsum board for construction purposes in which a mixture of gypsum, water and fibers provide the center or core of the board, and a composite coating of a fiberglass layer and a layer of fiberglass fleece covers one of the major surfaces of the core, with the fiberglass layer being embedded into the mixture and plaster favorably adhering to the outer surface of the fiberglass fleece layer. The other major surface of the core may be covered with a similar coating, or a layer, for example, of pasteboard.

Abstract: Particulate anhydrite, of whose particles from about 2 to 6% by weight have a particle size greater than about 5 mm, from about 13 to 23% by weight have a particle size of from about 5 to 3.15 mm, from about 33 to 40% by weight have a particle size of from about 3.15 to 1 mm, from about 17 to 23% by weight have a particle size of from about 1 to 0.2 mm, and from about 17 to 33% by weight have a particle size less than about 0.2 mm, will provide a mortar developing high early strength without requiring an excessive amount of water. If the particles having a size less than about 0.2 mm are activatingly ground to increase their energy content to above the minimum possible under ambient pressure and temperature conditions, a particularly speedy initial rise in strength takes place.