Abstract: The production of hardboard by the wet press process is speeded up by the incorporation of finely divided fibers in an aqueous slurry of otherwise fast draining wood fibers and a thermosetting binder so that a barrier of said fine fibers is formed during hot pressing of the mat and steam pressure is built up in the mat. The high pressure permits a curing temperature of from about 300.degree. F. to about 350.degree. F. in the core of the mat and a concomitant acceleration of the cure of the binder.

Abstract: Filter media sheets comprising particulate retention aid consisting of cellulose pulp of +100 to -100 Canadian Standard Freeness, and method of making the same.

Abstract: A ceramic fiber felt is obtained by mixing alumina crystalline ceramic fibers having at least about 60 weight percent of Al.sub.2 O.sub.3, the rest being SiO.sub.2 and impurities, and having a filament length ranging from 10 to 30 mm with aluminosilicate non-crystalline ceramic fiber having from about 40 to 70 weight percent of Al.sub.2 O.sub.3, the rest being primarily SiO.sub.2, impurities, and, optionally, including a small amount of metal oxides, and having a filament length ranging from 5 to 30 mm, the weight proportions of the alumina crystalline ceramic fibers to the aluminosilicate non-crystalline ceramic fiber being from about 4:6 to 7.5:2.5, and preferably from about 4:6 to 5:5, and binding the mixture of components with an organic binder.The ceramic fiber felt having a linear percentage shrinkage at 1400.degree. C. of only about 2% is very inexpensive compared to alumina ceramic fiber and is highly suited for use as or in furnace linings.

Abstract: The invention relates to a filtering material and a process for producing same. The proposed material can most advantageously be used in filter elements of internal-combustion engines, ventilation and air-conditioning systems, dust- and gas-collecting apparatus, and systems of purifying petroleum products of various viscosities and degrees of contamination, as well as for filtration of liquid foodstuffs, chemicals, and domestic sanitary and hygienic products. The filtering material contains 60 to 85% by volume of pores 5 to 40 microns in size, varying in diameter by no more than 5 microns. According to the proposed process, preshredded cellulose-containing material is refined in an air medium, at a concentration of at least 80% BD, to an average fiber length of 0.3 to 2.5 mm with subsequent dispersion of said fiber in an aqueous medium to obtain a uniform fibrous suspension with a concentration of 1.5 to 6% and make-up of the furnish from the suspension and additives.

Abstract: A multi-ply fibrous material is provided which is suitable for use as a wipe, swab, or sponge and which comprises a backing layer and at least one liquid absorbent layer. The backing layer is made of compactly assembled natural wood pulp fibers, bonded to each other with an adhesive binder to provide wet strength. The liquid absorbent layer is made of loosely assembled fibers including both natural wood pulp fibers and wettable thermoplastic synthetic wood pulp fibers which are irregularly arranged, intersecting, overlapping, and mechanically interengaged segments of the thermoplastic synthetic wood pulp fibers being heat fused and bonded to the backing layer in a discontinuous pattern of embossed areas alternating with unembossed areas.

Abstract: Process and apparatus are provided for the preparation of improved high-yield cellulose pulps, such as semichemical, chemimechanical, thermomechanical, and mechanical pulps, which comprises mechanically defibrating a mixture of particulate lignocellulosic materials which have been partially pulped and softened to different extents. Part of the raw lignocellulosic material is particulate form is washed, moistened with steam, impregnated with pulping chemicals and pulped to a yield of from about 65 to about 92%. Another part is treated in similar manner but either not pulped at all or, if pulped, pulped to a lesser extent. The two parts are mixed without intermediate washing, after which the mixture is subjected to a vapor phase pulping by heating to a temperature within the range from about 90 to about 200.degree. C. under pressure to obtain softening of the lignin, and delignification, after which the resulting product is mechanically defibrated to form cellulose pulp.

Abstract: An economical and uniform fibrous glass mat displaying improved tear strength and a wet forming process of making such a mat is disclosed herein. The mat, which is especially suitable as a carrier material in the manufacture of asphalt shingles or other such roofing products, includes a web of base fibers comprising individual monofilament glass fibers and reinforcement fibers in the form of glass fiber bundles interspersed throughout the web in a randomly oriented pattern. The mat also includes a binder substance to assist in holding the base fibers and reinforcement fiber bundles together.

Abstract: An economical and uniform fibrous glass mat displaying improved tear strength and a wet forming process of making such a mat is disclosed herein. The mat, which is especially suitable as a carrier material in the manufacture of asphalt shingles or other such roofing products, includes a web of base fibers comprising individual monofilament glass fibers and reinforcement fibers in the form of glass fiber bundles interspersed throughout the web in a randomly oriented pattern. The mat also includes a binder substance to assist in holding the base fibers and reinforcement fiber bundles together.

Abstract: A selected powdery form of a graft copolymer containing hydrophilic chains provides a highly moisture-absorbent media which is suitable for use in absorbent bodies, particularly those used for absorbing body exudates such as catamenial devices, diapers, wound dressings, surgical sponges, incontinence pads and the like. The powdered form of said copolymers is useful alone or in combination with other absorbent materials in making up the absorbent bodies.

Abstract: A nonwoven fabric having alternating stripes of high fiber density and low fiber density has fibers of at least 1/2 inch in length and fibers of less than 1/2 inch in length, preferably under 1/4 inch in length. The fabric is made in such a manner as to produce parallel twistless ribbon strands in the high fiber density areas containing both short and long fibers. The twistless ribbon strands are bridged together by the long fibers so as to form the nonwoven fabric. A majority of the bridging long fibers have at least a portion of their length included in adjacent twistless ribbon strands; said ribbon strands having at least one strand width space between said ribbon strands.

Abstract: High yield resin saturable papers containing total lignin, based on paper weight, in amounts from about 8 up to 15 percent are employed as core stock for high pressure decorative melamine laminates. At least 65 percent of the fibers should be hardwood fibers. Up to 35 percent of softwood fibers may be present but then the softwood lignin, based on paper weight, should not be greater than about 2.8 percent.

Abstract: A process is provided for producing novel convoluted, fiberized substantially nonfibrillated, cellulose fibers and novel sheet products from low moisture-content cellulose pulp, at a high through-put rate, which includes the application of contortive forces to a pulp mass under controlled operating conditions, wherein the feed rate, work space gap, and relative rate of movement of the working elements applying the contortive forces are correlated to maintain the work space filled with fibers under sufficient compression. Sheets made from these fibers exhibit excellent bulk, softness and absorbency properties, even when the formation process is conducted in an aqueous system, and even when substantial compacting forces are applied to the wet web processing.

Abstract: A novel web that can be produced by the process of the present invention is comprised of two different types of fibers, with the web characterized by having a predominance of one fiber type at one of its major faces, and a predominance of the other fiber type at the other of its major faces. The web includes a transition between the faces in which the predominance of the fibers decreases uniformly away from the face at which they predominate.

Abstract: An improved wet laid laminate comprising a first layer consisting of very short fibrous material and a binder and a second layer consisting of a combination of very short fibrous material and rayon or synthetic fibrous material substantially free of binder material and methods for manufacturing the improved laminates.

Abstract: High yield resin saturable papers containing total lignin, based on paper weight, in amounts from about 8 up to 15 percent are employed as core stock for high pressure decorative melamine laminates. At least 65 percent of the fibers should be hardwood fibers. Up to 35 percent of softwood fibers may be present but then the softwood lignin, based on paper weight, should not be greater than about 2.8 percent.