Glass Patents (Class 162/156)
  • Patent number: 4284538
    Abstract: A sizing composition is provided for glass fibers to render the glass fibers more dispersible in aqueous solutions. The sizing composition has present an aqueous dispersion of cationic imidazoline; aliphatic, aromatic and/or polymeric ester; and polyethylene in an amount equivalent to an amount in the range of about 0.1 to about 1.5 weight percent of the aqueous sizing composition based on an approximately 30 percent active aqueous dispersion. The sizing composition may also contain, depending on the use, other components such as starch, lubricant, emulsifying agents, wetting agents, plasticizers, biocides and the like.
    Type: Grant
    Filed: June 21, 1979
    Date of Patent: August 18, 1981
    Assignee: PPG Industries, Inc.
    Inventor: Roy R. Graham
  • Patent number: 4284470
    Abstract: High strength roofing products using a novel glass fiber mat are described herein. The roofing products include shingles and built up roofing membranes and systems.
    Type: Grant
    Filed: September 26, 1979
    Date of Patent: August 18, 1981
    Assignee: GAF Corporation
    Inventor: Alfredo A. Bondoc
  • Patent number: 4265704
    Abstract: What is provided herein is a method of dispersing bundles of glass fibers for making uniform glass fiber mats by the wet-laid process. Well-dispersed glass fiber compositions are prepared herein by agitating chopped bundles of glass fibers in water with a small amount of a surfactant which is a polyethoxylated derivative of the amide condensation product of fatty acids and polyethylenepolyamines. The dispersions are formed at relatively high glass fiber consistencies, and at low surfactant concentrations.
    Type: Grant
    Filed: March 30, 1979
    Date of Patent: May 5, 1981
    Assignee: GAF Corporation
    Inventor: Roop C. Nahta
  • Patent number: 4265979
    Abstract: A fiber-reinforced cementitious sheet is formed by first co-mixing in an air current reinforcing fibers such as glass fibers, and cementitious mineral materials in finely particulate form such as calcium sulfate hemihydrate, both in substantially dry form, depositing the mixture on a moving foraminous surface by means of the air current to form a sheet, applying water as by spraying in at least an amount which is stoichiometrically sufficiently to hydrate the calcium sulfate hemihydrate to the dihydrate form and to provide the necessary degree of plasticity to the mixture, densifying the sheet by compression, and setting and drying the sheet. A pair of sheets may be utilized as face sheets and, prior to setting, combined with a core formed of for example a calcium sulfate hemihydrate slurry, and the sheets and core then set and dried to form a paper-free gypsum board having excellent strength, surface hardness, and fire-resistant properties.
    Type: Grant
    Filed: November 7, 1979
    Date of Patent: May 5, 1981
    Assignee: United States Gypsum Company
    Inventors: Donald O. Baehr, David G. Izard
  • Patent number: 4258098
    Abstract: A glass fiber mat having excellent tensile strength and flexibility is provided herein. The mat includes a plurality of glass fibers and a binder therefor which is characterized by comprising about 25% to 90% by weight of a urea-formaldehyde resin and about 10% to 75% by weight of a styrene-butadiene latex copolymer containing about 0.1% to 5% by weight of an acrylamide type monomer.
    Type: Grant
    Filed: June 6, 1979
    Date of Patent: March 24, 1981
    Assignee: GAF Corporation
    Inventors: Alfredo A. Bondoc, Philip A. Cautilli
  • Patent number: 4248664
    Abstract: A board product containing glassy inorganic fibre such as mineral wool, in a matrix of a plastic clay such as ball clay. The amounts of clay and inorganic fibre are in the respective ranges 29 to 80 percent by weight and 15 to 55 percent by weight of the product, and its density is at least 500 kg/m.sup.3.The board can replace asbestos millboard and has the advantage of being asbestos-free. It can be made by the standard paper and board-making techniques, when preferred ingredients are pulp fibres e.g. cellulose pulp, and a complementary binder, particularly hydrolyzable starch, the latter enabling the product to be re-mouldable upon moistening with water.
    Type: Grant
    Filed: June 13, 1979
    Date of Patent: February 3, 1981
    Assignee: Turner & Newall Limited
    Inventors: Alan W. Atkinson, Richard H. Clucas, Robert A. Lancaster, Allen M. Perkins
  • Patent number: 4242404
    Abstract: What is provided herein is a glass fiber mat having a novel structure and high-strength properties which is particularly useful for roofing products, including built up roofing membranes and systems.The glass mat of the invention is comprised of two fibrous components, namely, individual filament glass fibers and extended glass fiber elements, which are formed in situ in a wet-laid process from original bundles of glass fibers. The individual filaments appear by conventional filamentation of the bundles. The extended fiber elements, however, are formed by longitudinal extension of a given bundle whose fibers are connected longitudinally. Thereby the effective length of a fiber element is very much greater than the length of the fibers therein. The fiber elements are further characterized by a non-uniform diameter, as contrasted to the fibers themselves, being thicker in the mid-section of the element where connection of fibers is maximized, and tapered towards its ends, where fiber connection is at a minimum.
    Type: Grant
    Filed: May 16, 1979
    Date of Patent: December 30, 1980
    Assignee: GAF Corporation
    Inventors: Alfredo A. Bondoc, V. Robert Canfield, B. Randall Ziegler
  • Patent number: 4234379
    Abstract: A process of producing a uniform fiber dispersion involves the use of an in-line dispersing chamber to provide an average fiber dwell time of only about ten minutes and less. The chamber is provided with a plurality of weedless, nonthrusting impellers that generate regions of reduced pressure and flow disruptive turbulence of high intensity, the turbulence being of sufficient intensity to rapidly open fiber bundles and disperse the individual long fibers during said dwell time within said chamber. The process produces a machine-made light weight glass fiber web material of exceptionally uniform fiber distribution. The web is comprised of micron diameter glass fibers having a fiber length of about 1/4 inch or more and a basis weight of about 5-30 grams/square meter. The web material exhibits an isolated multi-fiber defect count of less than 10 per 100 square feet and a visually perceptible overall uniform fiber distribution essentially devoid of "cloud effect" fiber density variations.
    Type: Grant
    Filed: June 2, 1978
    Date of Patent: November 18, 1980
    Assignee: The Dexter Corporation
    Inventors: Bernard W. Conway, Nelson L. Fegley, James Moran
  • Patent number: 4233368
    Abstract: A fiber-reinforced cementitious sheet is formed by first co-mixing in an air current reinforcing fibers such as glass fibers, and cementitious mineral materials in finely particulate form such as calcium sulfate hemihydrate, both in substantially dry form, depositing the mixture on a moving foraminous surface by means of the air current to form a sheet, applying water as by spraying in at least an amount which is stoichiometrically sufficient to hydrate the calcium sulfate hemihydrate to the dihydrate form and to provide the necessary degree of plasticity to the mixture, densifying the sheet by compression, and setting and drying the sheet. A pair of sheets may be utilized as face sheets and, prior to setting, combined with a core formed of for example a calcium sulfate hemihydrate slurry, and the sheets and core then set and dried to form a paper-free gypsum board having excellent strength, surface hardness, and fire-resistant properties.
    Type: Grant
    Filed: June 5, 1978
    Date of Patent: November 11, 1980
    Assignee: United States Gypsum Company
    Inventors: Donald O. Baehr, David G. Izard
  • Patent number: 4233353
    Abstract: High-strength built-up roofing (BUR) membranes and systems are provided herein. These BUR products are made using improved glass fiber mat structures having unusual tear resistance in place of organic felts.The glass fiber mats are constructed from two fibrous components, namely, individual filaments, which provide the uniform denseness required for impregnation of saturant asphalt in the interstices of the mat, and extended fiber elements formed by longitudinal extension and connection of fibers from bundles of glass fibers in a wet-laid process, which furnish tear resistance and tensile strength to the BUR membranes and systems.The BUR membranes and systems of this invention have exceedingly high strengths compared with commercially available products of similar construction, and, advantageously, they can be manufactured by a very economical process.
    Type: Grant
    Filed: May 16, 1979
    Date of Patent: November 11, 1980
    Assignee: GAF Corporation
    Inventors: Alfredo A. Bondoc, V. Robert Canfield, B. Randall Ziegler
  • Patent number: 4225383
    Abstract: A sheet which is a composite of (A) from about 1 percent to about 30 percent of a water-dispersible fiber such as wood fiber, (B) from about 2 percent to about 30 percent of a film-forming, water-insoluble, organic polymer such as a copolymer of styrene and butadiene and (C) from about 60 percent to about 95 percent of a finely-divided, substantially water-insoluble, non-fibrous, inorganic filler such as magnesium hydroxide is prepared by steps comprising:(I) providing an aqueous dispersion of the fiber;(II) mixing therewith (A) the inorganic filler and (B) the organic polymer in the form of an ionically stabilized latex;(III) colloidally destabilizing the resulting mixture to form a fibrous agglomerate in aqueous suspension;(IV) distributing and draining the aqueous dispersion on a porous substrate such as a wire to form a wet web; and(V) drying the web.
    Type: Grant
    Filed: December 14, 1978
    Date of Patent: September 30, 1980
    Assignee: The Dow Chemical Company
    Inventor: Kent B. McReynolds
  • Patent number: 4224103
    Abstract: A bonding composition for incombustible fibrous materials comprising (a) a water-soluble polymer containing hydrazide groups or its adduct with a water-soluble alkaline earth metal salt of an inorganic acid and (b) a heavy metal ion capable of forming chelate with the water-soluble polymer or its adduct. The bonding composition is employed as bonding agents to prepare incombustible sheet materials from incombustible fibrous materials by adding the components (a) and (b) to an aqueous dispersion of the fibrous materials and forming sheets or by forming wet or dry sheets containing the component (b) and then making the component (a) contain in the sheets. The bonding composition has excellent bonding effect and the polymer itself becomes incombustible, so incombustible sheet materials having excellent strength can be economically obtained.
    Type: Grant
    Filed: June 27, 1979
    Date of Patent: September 23, 1980
    Assignees: Otsuka Chemical Co. Ltd., Sansho Co., Ltd.
    Inventors: Hideo Yamaguchi, Masahiro Kobayashi, Atsunobu Mizote, Yoshiyuki Iwamuro
  • Patent number: 4221846
    Abstract: The invention disclosed relates to a novel paper composition for use as a separator material in electrical batteries. The paper composition 30-50%/w of glass fibers and 70-59%/w of a co-polymer of vinyl chloride and vinyl acetate.
    Type: Grant
    Filed: February 2, 1979
    Date of Patent: September 9, 1980
    Assignee: Her Majesty the Queen in right of Canada, as represented by the Minister of National Defence
    Inventors: William A. Armstrong, James A. Wheat
  • Patent number: 4210697
    Abstract: A process is provided for preparing hydrophobic porous fibrous sheet material suitable for use as a filter due to its inertness, strength, resistance to deterioration at elevated temperatures, and porosity, comprising impregnating a porous fibrous substrate with an aqueous dispersion consisting essentially of polytetrafluoroethylene or polytrifluorochloroethylene in an amount within the range from about 2 to about 40% by weight of the emulsion, and a silicone resin prepolymer such as a reactive polydimethylsiloxane in an amount within the range from about 0.1 to about 8% by weight of the emulsion; and drying the substrate at a temperature above about 525.degree. F.
    Type: Grant
    Filed: September 15, 1978
    Date of Patent: July 1, 1980
    Assignee: Pall Corporation
    Inventor: Joseph G. Adiletta
  • Patent number: 4200487
    Abstract: The glass mat made herein is comprised of two fibrous components, namely, individual filament glass fibers and extended glass fiber elements. These components are formed herein in situ in a wet-laid process from original bundles of glass fibers. The individual filaments appear by conventional filamentation of the bundles. The extended fiber elements, however, are formed by longitudinal extension of a given bundle whose fibers are connected longitudinally. Thereby the effective length of a fiber element is very much greater than the length of the fibers therein. The fiber elements are further characterized by a non-uniform diameter, as contrasted to the fibers themselves, being thicker in the midsection of the element where connection of fibers is maximized, and tapered towards its ends, where fiber connection is at a minimum.The extended fiber elements preferably predominate by weight of the fibrous content of the mat over the individual filaments.
    Type: Grant
    Filed: May 16, 1979
    Date of Patent: April 29, 1980
    Assignee: GAF Corporation
    Inventors: Alfredo A. Bondoc, V. Robert Canfield, B. Randall Ziegler
  • Patent number: 4194914
    Abstract: Highly heat-resisting ceramic fibers are manufactured either by simply coating the surface of ceramic fibers with at least one phosphorus compound or by further subjecting the resultant coated ceramic fibers to a heat treatment. The ceramic fibers having the surface coated with said phosphorus compound or the ceramic fibers having the phosphorus compound contained therein at a gradually decreasing concentration in the direction of increasing depth from the surface which are manufactured by the aforesaid method are capable of high resistance to heat.
    Type: Grant
    Filed: February 27, 1978
    Date of Patent: March 25, 1980
    Assignees: Agency of Industrial Science & Technology, Ministry of International Trade & Industry, Ibigawa Electric Industry Ltd.
    Inventors: Yoshiro Moriya, Kazuhito Ikai, Makoto Tanaka
  • Patent number: 4194946
    Abstract: Fiber reinforced cement is continuously prepared by forming a conveyor by connecting a plurality of suction boxes each having a perforated plate, contacting the perforated plates of the suction boxes with a filter cloth and moving the suction boxes with the filter cloth at a synchronous speed, feeding a cementitious slurry and a fiber on the filter cloth, removing excess water by suction from the cementitious slurry through a suction trough connected to a suction device, and releasing the suction on the suction boxes to separate the filter cloth from the perforated plates of the suction boxes.
    Type: Grant
    Filed: September 27, 1977
    Date of Patent: March 25, 1980
    Assignees: Asahi Glass Company, Ltd., Nakashima Manufacturing Company, Ltd.
    Inventors: Toshihiro Ootani, Mikio Kozuka, Ryuichiro Takeda, Hideaki Kurihara
  • Patent number: 4183782
    Abstract: This invention describes an aqueous, glass fiber dispersion composition for making uniform, high strength glass mats which comprises a plurality of glass fibers dispersed in an aqueous system comprising an effective amount of an amine oxide and a derivatized guar gum.A wet-laid process for making such mats using said dispersion composition also is described.
    Type: Grant
    Filed: July 11, 1978
    Date of Patent: January 15, 1980
    Assignee: GAF Corporation
    Inventor: A. A. Bondoc
  • Patent number: 4179331
    Abstract: In accordance with the present invention, there is provided herein improved glass fiber dispersions for making uniform glass fiber mats by the wet-laid process. The well dispersed glass fiber compositions of this invention usually are prepared by mixing chopped glass fiber bundles in water with a small amount of an amine oxide surfactant to disperse the bundles into individual fibers. As a feature of the invention, the dispersions may be formed at relatively high glass fiber consistencies. The resultant dispersions then are used to make very high quality glass fiber mats at high rates of production.
    Type: Grant
    Filed: November 15, 1977
    Date of Patent: December 18, 1979
    Assignee: GAF Corporation
    Inventor: Paritosh M. Chakrabarti
  • Patent number: 4178203
    Abstract: In accordance with the present invention, there is provided herein a method of increasing the strength of wet glass fiber mats prepared by the wet-laid process. The wet-strength of such freshly prepared glass fiber mats are improved in this invention by treating the wet mat with a dilute solution of an anionic surfactant. As a feature of the invention, the wet-strength of such mats are increased substantially so that they may be conveniently handled and transferred, even manually, for further processing, e.g. for applying binders and drying, into the finished glass fiber mat product.
    Type: Grant
    Filed: January 24, 1978
    Date of Patent: December 11, 1979
    Assignee: GAF Corporation
    Inventor: Paritosh M. Chakrabarti
  • Patent number: 4178204
    Abstract: In accordance with the present invention, there is provided herein a method of increasing the strength of wet glass fiber mats prepared by the wet-laid process. The wet-strength of such freshly prepared glass fiber mats are improved in this invention by treating the wet mat with a dilute solution of an anionic polyelectrolyte. As a feature of the invention, the wet-strength of such mats are increased substantially so that they may be conveniently handled and transferred, even manually, for further processing, e.g. for applying binders and drying, into the finished glass fiber mat product.
    Type: Grant
    Filed: January 24, 1978
    Date of Patent: December 11, 1979
    Assignee: GAF Corporation
    Inventor: Paritosh M. Chakrabarti
  • Patent number: 4178206
    Abstract: In accordance with the present invention, there is provided herein improved glass fiber dispersions for making uniform glass fiber mats by the wet-laid process. The well dispersed glass fiber compositions of this invention usually are prepared by mixing chopped glass fibers in water with a small amount of a select group of cationic quaternary ammonium compounds which have at least two long chain groups as part of the molecule. As features of the invention, the dispersions may be formed at relatively high glass fiber consistencies, in neutral or slightly alkaline solutions, and without generation of a high degree of foams. The resultant dispersions then are used to make very high quality glass fiber mats at high rates of production.
    Type: Grant
    Filed: February 10, 1978
    Date of Patent: December 11, 1979
    Assignee: GAF Corporation
    Inventor: Paritosh M. Chakrabarti
  • Patent number: 4118272
    Abstract: A continuous wet-laid process for making high-strength glass fiber mats is described. In the process, glass fibers of known quantity are fed directly into a water stream of given volume to form a flowing fiber slurry of predetermined fiber consistency. Immediately thereafter, the flow of the slurry is interrupted turbulently to form a uniform fiber dispersion. The dispersion then is conveyed quickly onto a moving mat-forming wire screen to form the desired mat. The water thus-removed is recirculated into the original stream to provide a continuous operation. The process may be used advantageously for making high-strength mats of relatively long glass fibers, which find utility in the manufacture of asphalt roofing shingles, and as backing sheets for vinyl flooring.
    Type: Grant
    Filed: March 3, 1977
    Date of Patent: October 3, 1978
    Assignee: GAF Corporation
    Inventors: Bertram Randall Ziegler, Edward J. Matteson
  • Patent number: 4102736
    Abstract: A process of preparing an inside-to-outside flow filter tube, which process comprises dispersing a plurality of glass fibers in water to form a water slurry of the fibers, the glass fibers having a diameter range of from about 0.001 to 10 microns; forming a filter tube comprising a wet mat of the glass fibers from the water slurry on a cylidrical mandrel; during the forming of the wet mat of fibers into a filter tube, incorporating an open-scrim, reinforcing sheet material within the internal wall thickness of the wet mat of fibers forming the filter tube, the sheet material extending generally the length of the filter tube and at least about 11/2 revolutions of the filter tube diameter; drying the filter tube containing the scrim sheet material within the filter tube wall; bonding the dried filter tube with a bonding agent at the junction of the glass fiber crossover points and with and through the scrim sheet material; and recovering an integral filter tube having a high burst strength.
    Type: Grant
    Filed: June 3, 1977
    Date of Patent: July 25, 1978
    Assignee: Whatman Reeve Angel Limited
    Inventors: Brian Arthur Head, Philip C. Kimball
  • Patent number: 4085001
    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.
    Type: Grant
    Filed: June 30, 1976
    Date of Patent: April 18, 1978
    Assignee: Asahi Glass Company, Ltd.
    Inventors: Tadashi Fukuwatari, Kiyotaka Mishima, Hiroshi Ichimura, Hideaki Kurihara
  • Patent number: 4078965
    Abstract: The specification discloses a novel composite coalescing filter tube and the method of making the same. In contrast to previous coalescing filters, which had layers of filter material sandwiched between relatively rigid support members, the present invention provides for a completely unitary coalescing filter tube wherein the various layers of the filter are successively vacuum formed one over the other on a forming fixture which is submerged in an appropriate glass fiber slurry mix, with the various layers being air dried, epoxy dipped, and cured as needed for the particular application. Since, during the vacuum forming process, glass fibers from one layer will interlock with glass fibers from the previously formed layer, a completely unitary coalescing filter tube is formed, preventing the problems of filter layer separation, channeling, pressure collapse and vibration damage which have occurred in past coalescing filters.
    Type: Grant
    Filed: July 7, 1975
    Date of Patent: March 14, 1978
    Assignee: Finite Filter Company
    Inventors: L. Joseph Berger, Jr., Denis D. Guequierre
  • Patent number: 4052256
    Abstract: Dispersions of glass fibers are produced by agitating a mixture comprising water, glass fibers and a water solution of a linear polysiloxane containing at least 6 silicon atoms, each of said silicon atoms having 2 non-hydrolyzable oleophilic groups attached thereto.
    Type: Grant
    Filed: February 4, 1976
    Date of Patent: October 4, 1977
    Assignee: Owens-Corning Fiberglas Corporation
    Inventors: Laurent C. Renaud, Clarence W. Charon
  • Patent number: 4052257
    Abstract: A size and dispersion system for, and a method for, the production of glass mats, the size comprising a methyl trimethoxysilane and a malto-dextrin, the dispersion system comprising a nonionic guar gum and an isostearic amide.
    Type: Grant
    Filed: January 8, 1976
    Date of Patent: October 4, 1977
    Assignee: Owens-Corning Fiberglas Corporation
    Inventors: Homer G. Hill, Kenneth L. Austin
  • Patent number: 4018647
    Abstract: A fiber web made by the wet method on a paper making machine is impregnated with a heat sensitized, foamed latex binder as the web passes through a screening area of the paper making machine.
    Type: Grant
    Filed: June 10, 1974
    Date of Patent: April 19, 1977
    Assignee: Chemische Industrie AKU-Goodrick B.V.
    Inventor: Popke Wietsma
  • Patent number: 4006054
    Abstract: A filter tube, which filter tube comprises a mass of interrelated nonwoven glass fibers, the fibers having a diameter of from about 0.001 to about 10 microns, the fibers bonded at the junctions of the fiber crossovers with a hardened silicone resin bonding agent, the fibers interrelated to form a semirigid mass of desired porosity suitable for use as a filter for gases or liquids.
    Type: Grant
    Filed: November 12, 1975
    Date of Patent: February 1, 1977
    Assignee: Whatman Reeve Angel Limited
    Inventor: Brian Arthur Head
  • Patent number: 3985427
    Abstract: A liquid crystal cell and method for its manufacture. The cell has a strip of microglass paper impregnated with liquid crystal material sandwiched between two substrates, each of which has conductive material plated thereon. If coincident selection of a point in the cell is desired, the conductive material on the substrates are in the form of parallel strips with the strip on one substrate being perpendicular to the strips on the other substrate and a layer of non-linear resistance material is deposited over the conductive material on one of the substrates.
    Type: Grant
    Filed: March 29, 1973
    Date of Patent: October 12, 1976
    Assignee: Bunker Ramo Corporation
    Inventor: James Vincent Masi
  • Patent number: 3979253
    Abstract: Beta Glass fibers are dispersed in a solution containing hydrochloric acid nd a hydrophobic fumed silicon dioxide treated with a silane thereby forming a slurry which is subjected to a sonic probe whereafter other glass fibers are mixed into said slurry and the mixture is formed into a glass fiber filter.
    Type: Grant
    Filed: February 5, 1976
    Date of Patent: September 7, 1976
    Assignee: The United States of America as represented by the Secretary of the Navy
    Inventor: Robert C. Clark
  • Patent number: 3974024
    Abstract: This invention relates to a process for continuously producing a dense board of cement-like material reinforced by glass fiber, which comprises (1) preparing a slurry of cement-like material; (2) simultaneously spraying the cement-like slurry and short lengths of glass fiber on a suction conveyor in such a manner that the cement-like slurry stream and the glass fiber stream intersect on the suction conveyor to form a dense mat of an intimate mixture of the two; and (3) dehydrating the mat by pulse-like intermittent suction using one or more suction boxes before the cement-like material begins to set, and to an apparatus used in carrying out the process.
    Type: Grant
    Filed: March 27, 1974
    Date of Patent: August 10, 1976
    Assignee: Onoda Cement Company, Ltd.
    Inventors: Tsuyoshi Yano, Kazumasa Ichikawa, Takao Take, Tetsuro Sasano
  • Patent number: 3937865
    Abstract: Non-woven glass-fiber webs for reinforcing plastics material carrying printed circuits are produced by the wet process from E-glass fibers bonded with polyvinyl alcohol. The polyvinyl alcohol used is a powder or suspension, has a degree of hydrolization of 98 - 100%, and a viscosity, as a 4% solution in water of 20.degree.C, of 20-100 cP. Preferably the polyvinyl alcohol has a degree of swelling at 20.degree.C of between 3 and 8, and in the dry form a particle size of between 50 and 180 .mu.. A plurality of these glass fiber webs are impregnated with a solution of an epoxy resin, arranged as a laminate, then compressed at elevated pressure and temperature to form the final laminate.
    Type: Grant
    Filed: January 25, 1974
    Date of Patent: February 10, 1976
    Assignee: Koninklijke Papierfabrieken Van Gelder Zonen N.V.
    Inventor: Hendrik Jongetjes