Abstract: A method of producing dry-process composition paper board from waste paper. Waste paper is particulated into flakes and the like fragments, conditioned for moisture content, and blended with an adhesive such as a synthetic thermosetting resin prior to forming by compression into mats which are cured under high pressure and temperature to form a rigid, cohesive paper flake board.The method obviates the need of sorting, pulping, cleaning and purification of waste paper and permits manufacture of structural panel boards in small recycling plants.

Abstract: A process for preparing glass fiber-reinforced cement sheets by dewatering a slurry wherein at least one member selected from asbestos, cotton, flax, hemp, wool, or silk fibers is added to the aqueous cement-glass fiber slurry. The sheets so produced have increased bending strengths and improved peeling resistance.

Abstract: A process for preparing a non-combustible hardboard sheet is disclosed. The process comprises the formation of relatively low density insulation board type product which is dried, whereafter the board is wetted on both sides and compressed at relatively high temperatures to form a dense non-combustible hardboard product.

Abstract: A composite dry process hardboard includes a hardboard panel consisting of pressed defibrated and refined wood chips, plus a surface layer of paper cemented to the hardboard by a cured resin made from phenolic resin mixed with water and ethylene glycol. If desired, an embossed pattern may be incorporated into pressing the paper overlay. In the subject process, first a mass of defibrated wood chips is mixed with a binding agent, the mass is then formed into a mat which is coated with a mixture of phenolic resin and polyhydric compound such as a polyhydric alcohol having a boiling point higher than water. Then, a dry sheet of paper is laid on the mat and the composite structure is then cured by the application of heat and pressure.

Abstract: Pressed fiberboard is produced in an S-1-S type process at much shorter than normal (prior art) press cycles. The process includes the use of fiber furnish having preselected shrinkage characteristics. This furnish is wet formed into a mat either with or without a paper overlay, which overlay may be decorated or undecorated, depending on the desired end use and pressed wet as in the S-1-S process, using control means, such as stop bars in the hot press, to limit the final separation distance between the hot plates in each press opening to provide full caliper reduced density board. By using a fiber furnish having selected shrinkage characteristics it has been found that the pressed board can be safely removed from the press in a semi-cured, moist condition, at unusually short press cycles. The use of said fiber furnish also permits the use of higher than normal (prior art) press temperatures without incurring discloration of the paper overlays.

Abstract: Wet pressed fiber board material of high resistance to bending is produced by preparing a layer of fiber from a water suspension of the fiber, said layer being de-watered and pressed to form a coherent flat sheet, wherein raw material is distributed over the surface of said layer in varying quantities and/or qualities in a manner such that the pressed board obtains strip-like surface portions which extend in at least one direction of the horizontal plane of the sheet, said strip-like surface portions having varying density and/or strength properties, whereby the finished board has a higher resistance to bending than a homogeneous sheet having substantially the same average density.

Abstract: A process for preparing a non-combustible hardboard sheet is disclosed. The process comprises the formation of relatively low density insulation board type product which is dried, whereafter the board is wetted on both sides and compressed at relatively high temperatures to form a dense non-combustible hardboard product.

Abstract: Lignocellulose fiber containing chips, preheated with steam liberated from a previous chip defibration, are dewatered and then defibrated in an atmosphere of saturated steam and in the presence of backwater and suspended in backwater to form a pulp suspension whereafter wet sheets are formed from the pulp suspension, water is mechanically removed from the wet sheets and recycled as backwater to be supplied simultaneously, with dewatered chips, to the defibration step and to form a new pulp suspension and said wet sheets are dried.

Abstract: Hardboard is produced by a process wherein wood solubles or sugars released principally during the pulp preparation stage are retained in a closed water system by collecting the process waters released during mechanical dewatering of the pulp to form a mat and returning such water to the system. The mat is dried by thermal evaporation with substantial quantities of sugars being deposited on the mat surfaces as a result. The mat is then pressed under conditions such as to cause flowing and caramelization of the surface sugars thus forming a crust or skin of the sugars on the mat surfaces, which sugars improve the board surface characteristics. A paper overlay may be applied to the mat prior to pressing and bonded thereto by the sugars to provide a paper overlaid hardboard.

Abstract: Fire retardant reconstituted cellulosic products are produced having fire retardancy substantially equal to conventional fire retardant products by impregnation of a portion of bark with a fire retardant and mixing said impregnated bark portion with another portion of bark which is untreated with a fire retardant. Additionally, a portion of wood chips is impregnated with a fire retardant and mixed with another portion of wood chips untreated with a fire retardant. Subsequently, the combined portions of bark and wood chips are formed into a three layer composite particleboard, having a bark core and wood chip surface, by pressing and heating.

Abstract: A composition board consisting essentially of a resin binder in the amount of between about 10 and 45 percent by weight and filler materials in the amount of between about 90 and 55 percent by weight and having a cross section of varying depth formed as a result of differentially compacting a dry blank to a thickness which is between about 30 and 70 percent of the original thickness at an average pressure of between about 600 psi and 1500 psi at an elevated temperature which is between about 275.degree. F. and 350.degree. F. so as to cause portions which were compacted to a greater degree to exhibit a darker color than portions which were compacted to a lesser degree to thereby produce a tonal effect on said composition board.

Abstract: An insulative material comprises a random network of ceramic fibers and a binder for holding the fibers together. In addition, it may include a filler material composed of hollow ceramic spheres which locate at the interstices of the fibrous network and increase the strength of the network. The insulative material can withstand extremely high temperatures and thermal shock without degradation, has an extremely low density, has excellent insulating properties, and has reasonably high compressive strength. The material is formed by making a slurry which contains the ceramic fibers, with or without the filler, and the binder; felting the slurry; subjecting the felt so formed to microwave energy for drying; and firing the dried felt at 2300.degree.-3200.degree.F. to increase its strength.