CA1328046C - Method of producing acoustical mineral fiberboard - Google Patents
Method of producing acoustical mineral fiberboardInfo
- Publication number
- CA1328046C CA1328046C CA 603670 CA603670A CA1328046C CA 1328046 C CA1328046 C CA 1328046C CA 603670 CA603670 CA 603670 CA 603670 A CA603670 A CA 603670A CA 1328046 C CA1328046 C CA 1328046C
- Authority
- CA
- Canada
- Prior art keywords
- slurry
- weight percent
- mineral
- felt
- dried
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Lifetime
Links
Classifications
-
- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B38/00—Porous mortars, concrete, artificial stone or ceramic ware; Preparation thereof
-
- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B14/00—Use of inorganic materials as fillers, e.g. pigments, for mortars, concrete or artificial stone; Treatment of inorganic materials specially adapted to enhance their filling properties in mortars, concrete or artificial stone
- C04B14/38—Fibrous materials; Whiskers
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B28—WORKING CEMENT, CLAY, OR STONE
- B28B—SHAPING CLAY OR OTHER CERAMIC COMPOSITIONS; SHAPING SLAG; SHAPING MIXTURES CONTAINING CEMENTITIOUS MATERIAL, e.g. PLASTER
- B28B1/00—Producing shaped prefabricated articles from the material
- B28B1/52—Producing shaped prefabricated articles from the material specially adapted for producing articles from mixtures containing fibres, e.g. asbestos cement
- B28B1/526—Producing shaped prefabricated articles from the material specially adapted for producing articles from mixtures containing fibres, e.g. asbestos cement by delivering the materials on a conveyor of the endless-belt type
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B28—WORKING CEMENT, CLAY, OR STONE
- B28B—SHAPING CLAY OR OTHER CERAMIC COMPOSITIONS; SHAPING SLAG; SHAPING MIXTURES CONTAINING CEMENTITIOUS MATERIAL, e.g. PLASTER
- B28B5/00—Producing shaped articles from the material in moulds or on moulding surfaces, carried or formed by, in, or on conveyors irrespective of the manner of shaping
- B28B5/02—Producing shaped articles from the material in moulds or on moulding surfaces, carried or formed by, in, or on conveyors irrespective of the manner of shaping on conveyors of the endless-belt or chain type
- B28B5/026—Producing shaped articles from the material in moulds or on moulding surfaces, carried or formed by, in, or on conveyors irrespective of the manner of shaping on conveyors of the endless-belt or chain type the shaped articles being of indefinite length
- B28B5/027—Producing shaped articles from the material in moulds or on moulding surfaces, carried or formed by, in, or on conveyors irrespective of the manner of shaping on conveyors of the endless-belt or chain type the shaped articles being of indefinite length the moulding surfaces being of the indefinite length type, e.g. belts, and being continuously fed
-
- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B26/00—Compositions of mortars, concrete or artificial stone, containing only organic binders, e.g. polymer or resin concrete
- C04B26/02—Macromolecular compounds
- C04B26/28—Polysaccharides or derivatives thereof
-
- D—TEXTILES; PAPER
- D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
- D21J—FIBREBOARD; MANUFACTURE OF ARTICLES FROM CELLULOSIC FIBROUS SUSPENSIONS OR FROM PAPIER-MACHE
- D21J1/00—Fibreboard
-
- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B2111/00—Mortars, concrete or artificial stone or mixtures to prepare them, characterised by specific function, property or use
- C04B2111/52—Sound-insulating materials
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02W—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO WASTEWATER TREATMENT OR WASTE MANAGEMENT
- Y02W30/00—Technologies for solid waste management
- Y02W30/50—Reuse, recycling or recovery technologies
- Y02W30/91—Use of waste materials as fillers for mortars or concrete
Abstract
Abstract A method of producing an acoustical mineral fiberboard comprising (a) forming an aqueous slurry of mineral fiber-con-taining solids suitable for forming an acoustical board, the solids content of the slurry being sufficiently high to bring about predominant formation of nodules of mineral fiber throughout the slurry upon mixing of the slurry;
(b) mixing the slurry to form the nodules of mineral fibers;
(c) dewatering the slurry to form a wet felt;
(d) drying the wet felt; and (e) texturing one surface of the dried felt without mechanically punching holes in the surface.
(b) mixing the slurry to form the nodules of mineral fibers;
(c) dewatering the slurry to form a wet felt;
(d) drying the wet felt; and (e) texturing one surface of the dried felt without mechanically punching holes in the surface.
Description
~ 1 1328046 .
METMOD OF WET-FOR~IING MINERAL FIBERBOARD
WITH FOR~TION OF FIBER NODULES
This invention relates to a wet process of manufacturing mineral-fiberboard products,and is concerned more particularly with the production of a mineral fiber acoustical board having a fine-textured appearance.
Acoustical boards which have high sound-absorption properties can be made from a water slurry of mineral wool fibers and a binder such as starch. In the manufacture of a desirable type of such boards, the mineral wool is introduced to the slurry in the form of pellets of nodulated mineral wool. A mat is then formed by continuously depositing the slurry upon a moving wire screen and removing the water by drainage and suction. The mat thus formed is dried and the binder set, after which the mat is cut into units of desired dimensions. The product may be provided with fissures or perforations or otherwise textured in order to improve its appearance and enhance its sound-absorption properties. Use of the nodulated mineral wool contributes to an especially attractive appearance in the finished product and also improves the porosity of the product, enabling it to absorb sound more readily.
A disadvantage of the above water-laid technique is that it xequires the pre-nodulation of the mineral wool and thus entails an additional process step. Also, various conven-tional methods of nodulating or granulating mineral wool unfortunately result in breakage of fibers, which diminishes the quality of the wool.
It would be desirable to provide a mineral fiberboard product which would have a combination of advantageous physical properties, including a highly decorative and pleasing appearance, by a wet-forming technique which would be relatively simple and economical and not require extra manufacturing steps, such as a pre-nodulation of mineral fib~rs.
. ',~ "' ~ '.
; -2- 1328~46 : ~
The present invention concerns an improved method of producing a wet felted board containing mineral fibers, whereby the fibers are nodulated during mixing of the board-forming ingredients instead of prior thereto.
The present invention also involves the production of a wet felted, fine-textured mineral fiberboard which is characterized by a combination of desirable physical properties including goods strength and sound-absorption properties and a highly decorative surface.
According to the present invention, there is provided a method of producing an acoustical, mineral fiberboard by the steps of forming an aqueous slurry of a mineral fiber-containing composition suitable for forming an acoustical board, dewatering the slurry to form a wet felt; optionally coating the wet felt and drying the wet felt characterized by the solids content of the slurry being sufficiently high to bring about substantial formation of nodulated mineral fiber upon mixing of the slurry; mixing the slurry to uniformly distribute the solids and form the nodules of mineral fiber; and abrading the surface of the dried felt to form a textured surface thereon.
The mineral fiberboard-forming slurry is preferably formed by mixing a composition comprising, based on the total weight of dry ingredients, from about 40 to 80 percent by weight of mineral fiber, 2 to 20 percent by weight of cellulosic fiber, 0 to 40 percent by weight of perlite, 0 to 30 percent by weight of clay, and 1 to 20 percent by weight of binder. These ingredients are combined with sufficient water to make up a slurry having a total solids of from about 4 to 10 percent by weight.
B
. . .
.:
1328~6 ~:
-- 3 -- :
As described below, in a preferred embodiment the ingredients, together with the water necessary to make up the required high slurry consistency, are added to conventional mixing and holding equipment from which they are flowed onto the board-forming wire of a machine such as a Fourdrinier through a conventional head box. The water-laid mat which is thus formed is compressed and dried. The resulting dried board surface is then modified to yield a finished product having a combination of desirable properties, including a visually appealing surface. The surface modification may include abrasion, such as by surface brushing or surface blasting (e.g., by a centrifugal force blasting machine), or any other `
treatment which results in a decorative appearance.
The invention will now be described with reference to the accompanying drawing which is a diagrammatic, side elevational view of an apparatus for carrying out the method of the present invention. ;
The process of the present invention is preferably carried out by forming an aqueous suspension of the material to be modulated, such as mineral wool or glass wool, and the other board-forming ingredients. In a typical preparation of a slurry in accordance with the invention, conventionally felted mineral wool is first added to a machine chest 1 containing water. Then the other ingredients, typically consisting of aqueous ~-suspensions of perlite and optionally clay, of starch, and of paper, are added to the machine chest. The machine chest agitator 2 is suitably operated to keep the slurry stirred up so that the ingredients, including the formed nodules of mineral wool, are uniformly distributed throughout the slurry. The rate and duration of agitation for forming an appropriate content of nodulated wool in the slurry can be readily determined through routine experimentation. Generally, the slurry is mixed for about :
10 to 60 minutes by means of a rotary agitator (impeller) - ' ~' .'."
. .
4 13280~6 r~volving at a rate of about 100 to 150 revolutions per minute.
The consistency or solids content of the board-forming slurry must be sufficiently high to bring about substantial formation of nodulated wool upon mixing of the slurry. When the dried board containing this nodulated mineral wool is subjected to surface modification, e.g., by sandblasting equipment, centrifugal force blasting equipment, brushes, coaters, or the like, a pleasing appearance is created on the board's surface~ The content of nodulated wool and the surface modification technique coact to produce the decorative surface on the fiberboard products of the invention.
The mineral wool-containing slurry can have a very wide range of consistencies, from relatively thick to almost unstirrable. The extremely thick slurries are less desirable because of the difficulty in processing them. The consistency is advantageously greater than ab~ut 5, more preferably 6, and most preferably 7 wt % solids. The aqueous fibrous slurry generally will have a consistency in the range from about 4 to 10, preferably 6 to 8, and more preferably 6.5 to 7.5, wt % solids. This use of high consistencies in accordance with the present invention is contrary to the conventional practice of keeping the solids content of the slurry as low as possible, such as between about 2-4 wt ~, so as to provide long and stringy fibers for optimum wet felting.
The mineral fiber component to be nodulated in accordance with the invention includes wool or fibers formed -from rock, slag, fused glass, glass mixtures thereof and other heat liquefiable raw materials capable of being converted into fibers~ The mineral fibers usually have a ratio of length to diameter which is equal to 10 or higher, with lengths which vary between 0.1 and 100 mm, more typically between 1 and 10 mm, and diameters within the range of 0.1 to 25 microns. The mineral wool employed in the ~
process of the invention typically has fiber diameters from ;-.
132~04~
about 4 to ~ microns, an acid/base ratio (molar) of about 0.80 to 1.10 and the following composition:
Mineral Wool Composition , TyPical (%) ~ange (%) aiO2 45 42-48 Al2O3 8 7-9 CaO 37 36-38 ;
MgO 7 6-9 The slurry also may contain cellulosic fibers and a binder. The solids of the slurry may comprise about 20% to 85% mineral fibers and about 2% to 15%, preferably 2% to 10%, cellulosic fibers, and the binding agent in an amount suffi-cient to form the board of the invention, as, e.g., about 5%
to 15%. `~
The cellulosic fibers may be wood fibers, primary or secondary paper fibers, cotton linters or the like. The -~
fiber length will generally be up to about 1/4 inch (6.35 mm) in length. Highly desirable ibers for use in the present invention are newsprint fibers which will generally have a length of from about 1/4 millimeter to about 5 millimeters with an average length of about 1 millimeter.
Numerous materials may be used as binding agents in the board-forming composition of the invention. Useful binders include starch, chemically modified starches, phenol-formal- , dehyde or other artificial resin binders, sodium silicate, glue, casein, rubber latex, aqueous rubber dispersions or emulsions, asphalt emulsions, or combinations thereof. The binder may include a minor amount of virgin kraft pulp, as `
disclosed in U. S. Patent No. 2,773,764.
A wide variety of fillers can be employed in the mineral fiber containing composition of the invention. The preferred ~
fillers are those which are inorganic. The filler or fillers generally constitute about 5 to 70, more preferably about 15 to 50, most preferably about 15 to 40 weight percent (dry solids basis) of the composition. Examples of suitable fillers include calcium carbonate, plaster and gypsum, . .
:: , ,~"~, ~ilica, sericite, expanded perlite, fly ash, vermiculite, n~tural clay, such as kaolin, bentonite or ball clay, talc, mica and other silicates.
Advantageously, the composition contains about 5 to 50, preferably 5 to 40, and more preferably 10 to 35, wt % (dry solids basis) of expanded perlite particles, which suitably have a density in the range from about 3.0 to 8.0, preferably 5.0 - 8.0, pcf (48.0 to 128.0, preferably 80.0 to 128.0, kg/m3). The expanded perlite used in the present invention has a typical screen analysis as follows:
Expanded Perlite Typical Sieve Analysis % Retained Sieve U. S. Sieve No. OPening TYPical Range 8 2.38 mm 0 0 16 1.19 mm 0 0-2 595 micron ~ 4-20 297 micron 55 35-60 100 149 micron 27 15-40 pan - 10 10-20 The slurry additionally may contain other auxiliary substances useful in conventional mineral fiberboard-forming compositions, such as preservatives, wetting agents, defoamers, retention aids, sizing agents, and broke. The amounts of such auxiliary additives can be readily determined by those skilled in the art.
A typical formulation (dry weight basis) for formation of the textured board of the present invention is as follows:
1328~a~6 , Preferred -I~lyredientTypical (%) Ranqe (%) Range (%) Mineral Wool ~5 40-80 ~0-70 Clay o 0-30 0-5 ~ ~
~erlite ~2 0-40 20-30 -Cellulosic Fibers 4 2-20 3-9 Starch g 5-~0 7-12 Retention Aid 0.03 0-1 0-0.1 A~ter the mineral wool containing slurry is agitated sufficiently to nodulate the wool, the slurried composition is delivered by pump 3 through pipe 4 to head box 5. The slurry is subsequently deposited on Fourdrinier wire 7 `~
through orifice 6 of head box 5. The first section 8 of the Fourdrinier wire permits free drainage of water from the material and further drainage is promoted by suction boxes 9 in section 10. As the slurry is brought in contact with the Fourdrinier machine and water of the slurry drains through the wire screen, a wet felted mat of the mineral fiber composition forms on the machine. The wet laid mat is ~ :
dewatered by the Fourdrinier machine to a solids content of about 20 to 40 weight percent.
The partially dried material is then prepressed to a ;;
thickness of about 0.4 to 0.8 inch (10 to 20 mm) by a ~ ;
plurality of press rolls 11. It will be appreciated that a single set of press rolls could be employed if desired.
After being pressed, the sheet product will generally have from about 60 to about 75% water. A coating may be applied to the pressed mat by means of feed-pipe 13 and coater 14.
After passing through press rolls 11, the wet mat is ~-transferred into dryer 12. At the outlet of the dryer, there is obtained a board having a moisture content of less than about 1.0%. The board is cut into smaller panels by saw arrangement 15. The dried product can be subjected to any -suitable conventional finishing apparatus, depending on the 35 applications for which it is intended. ~uch apparatuses may -include applicators for applying coatings to protect and/or decorate the product surface, such as bevel coaters, finish 1328~146 spray coaters, printers, multi-color decorative coaters, and the ]ike, and further drying equipment.
A fine-textured appearance can be created on one of the two major surfaces of the dried board by any suitable tex-turing means 17, such as by abrading, scoring, brushing, etc.The board may be advantageously turned over by an inverter 16 to present the smooth screen side for surface treatment. It has been found that a wheel blaster, such as that supplied by Wheelabrator-Frye, Inc. and known as a Tile Etch Machine, produces a surface which is fine-textured and visually appealing.
The wheel blaster uses centrifugal force to propel abrasive material against the board surface. Suitable abrasive material for eroding the surface includes metal grit, plastic abrasive, and walnut shells. Typically, the surface abrasion removes only about 0.01-0.04 inch (0.250 -1.016 mm) of the board surface in producing the desired look.
The finish coat is suitably applied to the board surface after its treatment by the blasting machine.
In accordance with the process of the present invention, the mineral fiber-containing slurry is typically formed into a textured fiberboard of from about 0.4 to 0.8 inch (10 mm to 20 mm) thick, preferably from about 0.5 to 0.8 inch (12.7 to 20.3 mm) thick, and having a density of from about 10 to 25 pounds per cubic foot (160 to 400 kg per cubic meter), pref-erably from about 10 to 20 pounds per cubic foot ~160 to 320 kg per cubic meter). The noise reduction coefficient ~NRC) of the board is generally from about 0.50 - 0.70, and preferably greater than 0.55, and can be secured without the use of mechanical punching or fissuring, although, if desired, the latter means of perforating the board surface can be employed to further enhance the NRC.
The present invention provides a unique method of producing from a mineral wool-containing slurry a wet-felted mineral ceiling product with a subtly-textured surface appearance. The board-forming slurry is formulated to contain a high consistency (solids content), such as from `~
13280~6 ``
about 6.0 - 7.5 wt %, and advantageously to contain a rela-tively high mineral wool content (e.g.,>55 wt %, dry solids basis) and low cellulosic fiber content. Wet mixing of this L' slurry to hom~genize it results in nodulation or balling-up of the mineral wool. After tne nodulated wool-containing slurry is formed into a wet mat and dried, the surface of the dried board can then be modified, such as by wheel blasting or brushing, to produce a fine-textured fibrous product which is eminently suitable for use as an acoustical tile or panel for ceiling and wall decoration. The product has the desired appearance and good acoustical value for such purposes without the conventional pin punched perforations normally provided in acoustical ceiling board. The process of the invention is an improvement over the prior practice of using pre-nodulated wool in fiberboard formation by eliminating the need for such pre-nodulation. By providing an "hydraulic cushion" during nodulation, the present process has the further advantage of doing less mechanical damage to the wool fibers than the pre-nodulating technique.
The present invention is further illustrated by the following examples in which all percentages are by weight.
This example illustrates with reference to the drawing ~, the large-scale production in accordance with the present 25 invention of a wet-felted ceiling product. ~ `
The formulation utilized in manufacturing the product consisted of the following ingredients in the listed per-centages by weight:
Ingredient %
Mineral Wool 54.3 Clay 17.0 ;
Perlite 15.0 Newsprint 6.5 Starch 7.2 ~etention Aid0.05 '~
The ingredients were diluted with water to form a slurry in machine chest 1. Wet mixing of the slurry, which had a stock :
1328~46 onsistency of 5.5 wt %, nodulated the mineral wool. Theslurry was -transferred to head box 5 and next deposited on Fourdrinier wire 7. The slurry was dewatered in a conven-tional manner on the Fourdrinier machine to form a wet felt or mat of interlocked fibers. The partially dewatered fibrous mat was next passed through a press section compris-ing pressing rolls 11, which densified the mat and provided a wet mat of uniform thickness (about one inch - 25 mm) with a moisture content of about 65%. After leaving the press section, the wet mat was conveyed to dryer 12.
After being dried, the board product was subjected to various conventional finishing steps, which included cutting into appropriate sizes and cleaning. After being flipped over by inverter 16, the board product was then abraded on the screen side by a wheel blaster, and this side was coated to produce textured fiberboards of the invention.
Mineral ceiling panels made in accordance with the foregoing procedure had the following physical properties:
Average Thickness, in 0.78-0.79 (mm) ( 19.8- 20.1) Average Dencity, lb/cu ft17.4-18.2 " (kg/m3) (278.7-291.6) Transverse Strength, lb 42-60 ~ -" (kg)(force) ( 19.1- 27.3) NRC 0.50 Another wet-felted ceiling product was manufactured, utilizing the following ingredients in the listed percentages ~ ~
by weight: - ~ -In~redient %
Mineral Wool 67.0 Perlite 22.7 Newsprint 8.4 Starch 7.3 Retention Aie 0.05 . ' .
A slurry of the ingredients having a consistency of 5.5 wt %
was formed and mixed to nodulate the mineral wool. The slurry was converted to textured fiberboards in accordance with the procedure described in Example 1. The process was 5 repeated except that feed-pipe 13 and coater 14 were employed -~
to coat the mat and thus provide, after the coated mat was turned upside down by inverter 16, a backsizing on the finished fiberboards. ;
Backsized and unbacksized mineral ceiling panels made in accordance with the foregoing procedures had the physical characteristics reported in the following Table:
Table Evaluation of Fiberboards Physical Property Value ASTM E-84 Tunnel Test RatingClass I with a 20 Flame Spread and 10 Smoke Developed Average Thickness, in 0.739 ;
" (mm) (18.8) Average Density, lb/cu ft 13.3 " ~kg/m3) (213.1) Transverse Strength, backsized, lb 26.9 " (kg)(force) (12.2) Transverse Strength, unbacksized, lb 19.0 n (kg)(force) t8.6) NRC
! 2'x 2' ~ca 600mm x 600mm) backsized 50 2'x 2' (ca 600mm x 600mm) unbacksized 50 2'x 4' (ca 600mm x 1200mm) backsized 55 2'x 4' (ca 600mm x 1200mm)unbacksized 50 "' .,.
- ':' ; ., ,
METMOD OF WET-FOR~IING MINERAL FIBERBOARD
WITH FOR~TION OF FIBER NODULES
This invention relates to a wet process of manufacturing mineral-fiberboard products,and is concerned more particularly with the production of a mineral fiber acoustical board having a fine-textured appearance.
Acoustical boards which have high sound-absorption properties can be made from a water slurry of mineral wool fibers and a binder such as starch. In the manufacture of a desirable type of such boards, the mineral wool is introduced to the slurry in the form of pellets of nodulated mineral wool. A mat is then formed by continuously depositing the slurry upon a moving wire screen and removing the water by drainage and suction. The mat thus formed is dried and the binder set, after which the mat is cut into units of desired dimensions. The product may be provided with fissures or perforations or otherwise textured in order to improve its appearance and enhance its sound-absorption properties. Use of the nodulated mineral wool contributes to an especially attractive appearance in the finished product and also improves the porosity of the product, enabling it to absorb sound more readily.
A disadvantage of the above water-laid technique is that it xequires the pre-nodulation of the mineral wool and thus entails an additional process step. Also, various conven-tional methods of nodulating or granulating mineral wool unfortunately result in breakage of fibers, which diminishes the quality of the wool.
It would be desirable to provide a mineral fiberboard product which would have a combination of advantageous physical properties, including a highly decorative and pleasing appearance, by a wet-forming technique which would be relatively simple and economical and not require extra manufacturing steps, such as a pre-nodulation of mineral fib~rs.
. ',~ "' ~ '.
; -2- 1328~46 : ~
The present invention concerns an improved method of producing a wet felted board containing mineral fibers, whereby the fibers are nodulated during mixing of the board-forming ingredients instead of prior thereto.
The present invention also involves the production of a wet felted, fine-textured mineral fiberboard which is characterized by a combination of desirable physical properties including goods strength and sound-absorption properties and a highly decorative surface.
According to the present invention, there is provided a method of producing an acoustical, mineral fiberboard by the steps of forming an aqueous slurry of a mineral fiber-containing composition suitable for forming an acoustical board, dewatering the slurry to form a wet felt; optionally coating the wet felt and drying the wet felt characterized by the solids content of the slurry being sufficiently high to bring about substantial formation of nodulated mineral fiber upon mixing of the slurry; mixing the slurry to uniformly distribute the solids and form the nodules of mineral fiber; and abrading the surface of the dried felt to form a textured surface thereon.
The mineral fiberboard-forming slurry is preferably formed by mixing a composition comprising, based on the total weight of dry ingredients, from about 40 to 80 percent by weight of mineral fiber, 2 to 20 percent by weight of cellulosic fiber, 0 to 40 percent by weight of perlite, 0 to 30 percent by weight of clay, and 1 to 20 percent by weight of binder. These ingredients are combined with sufficient water to make up a slurry having a total solids of from about 4 to 10 percent by weight.
B
. . .
.:
1328~6 ~:
-- 3 -- :
As described below, in a preferred embodiment the ingredients, together with the water necessary to make up the required high slurry consistency, are added to conventional mixing and holding equipment from which they are flowed onto the board-forming wire of a machine such as a Fourdrinier through a conventional head box. The water-laid mat which is thus formed is compressed and dried. The resulting dried board surface is then modified to yield a finished product having a combination of desirable properties, including a visually appealing surface. The surface modification may include abrasion, such as by surface brushing or surface blasting (e.g., by a centrifugal force blasting machine), or any other `
treatment which results in a decorative appearance.
The invention will now be described with reference to the accompanying drawing which is a diagrammatic, side elevational view of an apparatus for carrying out the method of the present invention. ;
The process of the present invention is preferably carried out by forming an aqueous suspension of the material to be modulated, such as mineral wool or glass wool, and the other board-forming ingredients. In a typical preparation of a slurry in accordance with the invention, conventionally felted mineral wool is first added to a machine chest 1 containing water. Then the other ingredients, typically consisting of aqueous ~-suspensions of perlite and optionally clay, of starch, and of paper, are added to the machine chest. The machine chest agitator 2 is suitably operated to keep the slurry stirred up so that the ingredients, including the formed nodules of mineral wool, are uniformly distributed throughout the slurry. The rate and duration of agitation for forming an appropriate content of nodulated wool in the slurry can be readily determined through routine experimentation. Generally, the slurry is mixed for about :
10 to 60 minutes by means of a rotary agitator (impeller) - ' ~' .'."
. .
4 13280~6 r~volving at a rate of about 100 to 150 revolutions per minute.
The consistency or solids content of the board-forming slurry must be sufficiently high to bring about substantial formation of nodulated wool upon mixing of the slurry. When the dried board containing this nodulated mineral wool is subjected to surface modification, e.g., by sandblasting equipment, centrifugal force blasting equipment, brushes, coaters, or the like, a pleasing appearance is created on the board's surface~ The content of nodulated wool and the surface modification technique coact to produce the decorative surface on the fiberboard products of the invention.
The mineral wool-containing slurry can have a very wide range of consistencies, from relatively thick to almost unstirrable. The extremely thick slurries are less desirable because of the difficulty in processing them. The consistency is advantageously greater than ab~ut 5, more preferably 6, and most preferably 7 wt % solids. The aqueous fibrous slurry generally will have a consistency in the range from about 4 to 10, preferably 6 to 8, and more preferably 6.5 to 7.5, wt % solids. This use of high consistencies in accordance with the present invention is contrary to the conventional practice of keeping the solids content of the slurry as low as possible, such as between about 2-4 wt ~, so as to provide long and stringy fibers for optimum wet felting.
The mineral fiber component to be nodulated in accordance with the invention includes wool or fibers formed -from rock, slag, fused glass, glass mixtures thereof and other heat liquefiable raw materials capable of being converted into fibers~ The mineral fibers usually have a ratio of length to diameter which is equal to 10 or higher, with lengths which vary between 0.1 and 100 mm, more typically between 1 and 10 mm, and diameters within the range of 0.1 to 25 microns. The mineral wool employed in the ~
process of the invention typically has fiber diameters from ;-.
132~04~
about 4 to ~ microns, an acid/base ratio (molar) of about 0.80 to 1.10 and the following composition:
Mineral Wool Composition , TyPical (%) ~ange (%) aiO2 45 42-48 Al2O3 8 7-9 CaO 37 36-38 ;
MgO 7 6-9 The slurry also may contain cellulosic fibers and a binder. The solids of the slurry may comprise about 20% to 85% mineral fibers and about 2% to 15%, preferably 2% to 10%, cellulosic fibers, and the binding agent in an amount suffi-cient to form the board of the invention, as, e.g., about 5%
to 15%. `~
The cellulosic fibers may be wood fibers, primary or secondary paper fibers, cotton linters or the like. The -~
fiber length will generally be up to about 1/4 inch (6.35 mm) in length. Highly desirable ibers for use in the present invention are newsprint fibers which will generally have a length of from about 1/4 millimeter to about 5 millimeters with an average length of about 1 millimeter.
Numerous materials may be used as binding agents in the board-forming composition of the invention. Useful binders include starch, chemically modified starches, phenol-formal- , dehyde or other artificial resin binders, sodium silicate, glue, casein, rubber latex, aqueous rubber dispersions or emulsions, asphalt emulsions, or combinations thereof. The binder may include a minor amount of virgin kraft pulp, as `
disclosed in U. S. Patent No. 2,773,764.
A wide variety of fillers can be employed in the mineral fiber containing composition of the invention. The preferred ~
fillers are those which are inorganic. The filler or fillers generally constitute about 5 to 70, more preferably about 15 to 50, most preferably about 15 to 40 weight percent (dry solids basis) of the composition. Examples of suitable fillers include calcium carbonate, plaster and gypsum, . .
:: , ,~"~, ~ilica, sericite, expanded perlite, fly ash, vermiculite, n~tural clay, such as kaolin, bentonite or ball clay, talc, mica and other silicates.
Advantageously, the composition contains about 5 to 50, preferably 5 to 40, and more preferably 10 to 35, wt % (dry solids basis) of expanded perlite particles, which suitably have a density in the range from about 3.0 to 8.0, preferably 5.0 - 8.0, pcf (48.0 to 128.0, preferably 80.0 to 128.0, kg/m3). The expanded perlite used in the present invention has a typical screen analysis as follows:
Expanded Perlite Typical Sieve Analysis % Retained Sieve U. S. Sieve No. OPening TYPical Range 8 2.38 mm 0 0 16 1.19 mm 0 0-2 595 micron ~ 4-20 297 micron 55 35-60 100 149 micron 27 15-40 pan - 10 10-20 The slurry additionally may contain other auxiliary substances useful in conventional mineral fiberboard-forming compositions, such as preservatives, wetting agents, defoamers, retention aids, sizing agents, and broke. The amounts of such auxiliary additives can be readily determined by those skilled in the art.
A typical formulation (dry weight basis) for formation of the textured board of the present invention is as follows:
1328~a~6 , Preferred -I~lyredientTypical (%) Ranqe (%) Range (%) Mineral Wool ~5 40-80 ~0-70 Clay o 0-30 0-5 ~ ~
~erlite ~2 0-40 20-30 -Cellulosic Fibers 4 2-20 3-9 Starch g 5-~0 7-12 Retention Aid 0.03 0-1 0-0.1 A~ter the mineral wool containing slurry is agitated sufficiently to nodulate the wool, the slurried composition is delivered by pump 3 through pipe 4 to head box 5. The slurry is subsequently deposited on Fourdrinier wire 7 `~
through orifice 6 of head box 5. The first section 8 of the Fourdrinier wire permits free drainage of water from the material and further drainage is promoted by suction boxes 9 in section 10. As the slurry is brought in contact with the Fourdrinier machine and water of the slurry drains through the wire screen, a wet felted mat of the mineral fiber composition forms on the machine. The wet laid mat is ~ :
dewatered by the Fourdrinier machine to a solids content of about 20 to 40 weight percent.
The partially dried material is then prepressed to a ;;
thickness of about 0.4 to 0.8 inch (10 to 20 mm) by a ~ ;
plurality of press rolls 11. It will be appreciated that a single set of press rolls could be employed if desired.
After being pressed, the sheet product will generally have from about 60 to about 75% water. A coating may be applied to the pressed mat by means of feed-pipe 13 and coater 14.
After passing through press rolls 11, the wet mat is ~-transferred into dryer 12. At the outlet of the dryer, there is obtained a board having a moisture content of less than about 1.0%. The board is cut into smaller panels by saw arrangement 15. The dried product can be subjected to any -suitable conventional finishing apparatus, depending on the 35 applications for which it is intended. ~uch apparatuses may -include applicators for applying coatings to protect and/or decorate the product surface, such as bevel coaters, finish 1328~146 spray coaters, printers, multi-color decorative coaters, and the ]ike, and further drying equipment.
A fine-textured appearance can be created on one of the two major surfaces of the dried board by any suitable tex-turing means 17, such as by abrading, scoring, brushing, etc.The board may be advantageously turned over by an inverter 16 to present the smooth screen side for surface treatment. It has been found that a wheel blaster, such as that supplied by Wheelabrator-Frye, Inc. and known as a Tile Etch Machine, produces a surface which is fine-textured and visually appealing.
The wheel blaster uses centrifugal force to propel abrasive material against the board surface. Suitable abrasive material for eroding the surface includes metal grit, plastic abrasive, and walnut shells. Typically, the surface abrasion removes only about 0.01-0.04 inch (0.250 -1.016 mm) of the board surface in producing the desired look.
The finish coat is suitably applied to the board surface after its treatment by the blasting machine.
In accordance with the process of the present invention, the mineral fiber-containing slurry is typically formed into a textured fiberboard of from about 0.4 to 0.8 inch (10 mm to 20 mm) thick, preferably from about 0.5 to 0.8 inch (12.7 to 20.3 mm) thick, and having a density of from about 10 to 25 pounds per cubic foot (160 to 400 kg per cubic meter), pref-erably from about 10 to 20 pounds per cubic foot ~160 to 320 kg per cubic meter). The noise reduction coefficient ~NRC) of the board is generally from about 0.50 - 0.70, and preferably greater than 0.55, and can be secured without the use of mechanical punching or fissuring, although, if desired, the latter means of perforating the board surface can be employed to further enhance the NRC.
The present invention provides a unique method of producing from a mineral wool-containing slurry a wet-felted mineral ceiling product with a subtly-textured surface appearance. The board-forming slurry is formulated to contain a high consistency (solids content), such as from `~
13280~6 ``
about 6.0 - 7.5 wt %, and advantageously to contain a rela-tively high mineral wool content (e.g.,>55 wt %, dry solids basis) and low cellulosic fiber content. Wet mixing of this L' slurry to hom~genize it results in nodulation or balling-up of the mineral wool. After tne nodulated wool-containing slurry is formed into a wet mat and dried, the surface of the dried board can then be modified, such as by wheel blasting or brushing, to produce a fine-textured fibrous product which is eminently suitable for use as an acoustical tile or panel for ceiling and wall decoration. The product has the desired appearance and good acoustical value for such purposes without the conventional pin punched perforations normally provided in acoustical ceiling board. The process of the invention is an improvement over the prior practice of using pre-nodulated wool in fiberboard formation by eliminating the need for such pre-nodulation. By providing an "hydraulic cushion" during nodulation, the present process has the further advantage of doing less mechanical damage to the wool fibers than the pre-nodulating technique.
The present invention is further illustrated by the following examples in which all percentages are by weight.
This example illustrates with reference to the drawing ~, the large-scale production in accordance with the present 25 invention of a wet-felted ceiling product. ~ `
The formulation utilized in manufacturing the product consisted of the following ingredients in the listed per-centages by weight:
Ingredient %
Mineral Wool 54.3 Clay 17.0 ;
Perlite 15.0 Newsprint 6.5 Starch 7.2 ~etention Aid0.05 '~
The ingredients were diluted with water to form a slurry in machine chest 1. Wet mixing of the slurry, which had a stock :
1328~46 onsistency of 5.5 wt %, nodulated the mineral wool. Theslurry was -transferred to head box 5 and next deposited on Fourdrinier wire 7. The slurry was dewatered in a conven-tional manner on the Fourdrinier machine to form a wet felt or mat of interlocked fibers. The partially dewatered fibrous mat was next passed through a press section compris-ing pressing rolls 11, which densified the mat and provided a wet mat of uniform thickness (about one inch - 25 mm) with a moisture content of about 65%. After leaving the press section, the wet mat was conveyed to dryer 12.
After being dried, the board product was subjected to various conventional finishing steps, which included cutting into appropriate sizes and cleaning. After being flipped over by inverter 16, the board product was then abraded on the screen side by a wheel blaster, and this side was coated to produce textured fiberboards of the invention.
Mineral ceiling panels made in accordance with the foregoing procedure had the following physical properties:
Average Thickness, in 0.78-0.79 (mm) ( 19.8- 20.1) Average Dencity, lb/cu ft17.4-18.2 " (kg/m3) (278.7-291.6) Transverse Strength, lb 42-60 ~ -" (kg)(force) ( 19.1- 27.3) NRC 0.50 Another wet-felted ceiling product was manufactured, utilizing the following ingredients in the listed percentages ~ ~
by weight: - ~ -In~redient %
Mineral Wool 67.0 Perlite 22.7 Newsprint 8.4 Starch 7.3 Retention Aie 0.05 . ' .
A slurry of the ingredients having a consistency of 5.5 wt %
was formed and mixed to nodulate the mineral wool. The slurry was converted to textured fiberboards in accordance with the procedure described in Example 1. The process was 5 repeated except that feed-pipe 13 and coater 14 were employed -~
to coat the mat and thus provide, after the coated mat was turned upside down by inverter 16, a backsizing on the finished fiberboards. ;
Backsized and unbacksized mineral ceiling panels made in accordance with the foregoing procedures had the physical characteristics reported in the following Table:
Table Evaluation of Fiberboards Physical Property Value ASTM E-84 Tunnel Test RatingClass I with a 20 Flame Spread and 10 Smoke Developed Average Thickness, in 0.739 ;
" (mm) (18.8) Average Density, lb/cu ft 13.3 " ~kg/m3) (213.1) Transverse Strength, backsized, lb 26.9 " (kg)(force) (12.2) Transverse Strength, unbacksized, lb 19.0 n (kg)(force) t8.6) NRC
! 2'x 2' ~ca 600mm x 600mm) backsized 50 2'x 2' (ca 600mm x 600mm) unbacksized 50 2'x 4' (ca 600mm x 1200mm) backsized 55 2'x 4' (ca 600mm x 1200mm)unbacksized 50 "' .,.
- ':' ; ., ,
Claims (8)
1. A method of producing an acoustical, mineral fiberboard by the steps of forming an aqueous slurry of a mineral fiber-containing composition for forming an acoustical board, the solids content of the slurry being between 4 and 10 weight percent of the weight of the slurry to bring about substantial formation of nodulated mineral fiber upon mixing of the slurry; mixing the slurry to uniformly distribute the solids and form the nodules of mineral fiber; dewatering the slurry to form a wet felt;
drying the wet felt, and abrading the surface of the dried felt to form a textured surface thereon.
drying the wet felt, and abrading the surface of the dried felt to form a textured surface thereon.
2. The method of claim 1, wherein the solids content of the initially formed slurry ranges from 5 weight percent to 7 weight percent, said solids content comprises from 5 to 20 weight percent of binder; 20 to 85 weight percent mineral fibers; 2 to 15 weight percent of cellulosic fibers.
3. The method of claims 1 or 2, wherein the solids content of the initially formed slurry comprises 40 to 80 weight percent mineral wool; 0 to 30 weight percent of clay; 0 to 40 weight percent of perlite; and 5 to 20 weight percent of starch.
4. The method of claim 1 or 2, wherein the abrasion is accomplished by a wheel blaster which uses centrifugal force to propel abrasive material against the surface, the abrasive material preferably being walnut shells.
5. The method of claim 1 or 2, wherein the surface of the dried felt is mechanically punched or fissured to further enhance the noise reduction coefficient.
6. The method of any of claims 1 or 2, wherein the slurry is deposited on a moving wire screen to form a partially dewatered wet felt, the partially dewatered wet felt is compressed to further remove water therefrom, and the wet felt is dried.
7. The method of claim 6, wherein a textured surface is formed on said dried felt by abrading the surface of the dried felt which did not contact the wire screen during dewatering, the abrasion preferably being accomplished by a wheel blaster which uses centrifugal force to propel abrasive material against the surface, the abrasive material preferably being walnut shells.
8. The method of claim 1 or 2, wherein a coating is applied to the wet felt.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US210,446 | 1988-06-23 | ||
| US07/210,446 US4911788A (en) | 1988-06-23 | 1988-06-23 | Method of wet-forming mineral fiberboard with formation of fiber nodules |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1328046C true CA1328046C (en) | 1994-03-29 |
Family
ID=22782937
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA 603670 Expired - Lifetime CA1328046C (en) | 1988-06-23 | 1989-06-22 | Method of producing acoustical mineral fiberboard |
Country Status (6)
| Country | Link |
|---|---|
| US (1) | US4911788A (en) |
| EP (1) | EP0347809B1 (en) |
| JP (1) | JP2871728B2 (en) |
| KR (1) | KR100196232B1 (en) |
| CA (1) | CA1328046C (en) |
| DE (1) | DE68913824T2 (en) |
Families Citing this family (39)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5013405A (en) * | 1987-01-12 | 1991-05-07 | Usg Interiors, Inc. | Method of making a low density frothed mineral wool |
| US5071511A (en) * | 1988-06-23 | 1991-12-10 | The Celotex Corporation | Acoustical mineral fiberboard |
| US5158014A (en) * | 1988-07-09 | 1992-10-27 | Rich, Hengstenberg Gmbh & Co. | Arrangement for apportioning and dispensing fibrous goods, particularly sauerkraut |
| US5632848A (en) * | 1989-10-12 | 1997-05-27 | Georgia-Pacific Corporation | Continuous processing equipment for making fiberboard |
| CA2029072A1 (en) * | 1989-11-09 | 1991-05-10 | Alan L. Boyd | Texturing of acoustical mineral fiberboard with wheel blast machine |
| EP0655966B1 (en) * | 1992-08-06 | 2001-03-21 | Georgia-Pacific Corporation | Continuous processing equipment for making fiberboard |
| US6068804A (en) * | 1994-04-25 | 2000-05-30 | Celotex Corporation | Process for making expansion joint material |
| US5945182A (en) * | 1995-02-14 | 1999-08-31 | G-P Gypsum Corporation | Fire-resistant members containing gypsum fiberboard |
| SE513941C2 (en) * | 1996-12-16 | 2000-11-27 | John Fellert | Sound absorbing plaster mills mainly comprising cotton fibers and expanded mineral |
| US5911818A (en) * | 1997-08-20 | 1999-06-15 | Usg Interiors, Inc. | Acoustical tile composition |
| US5964934A (en) * | 1997-12-18 | 1999-10-12 | Usg Interiors, Inc. | Acoustical tile containing treated perlite |
| DE19823723A1 (en) * | 1998-05-08 | 1999-11-11 | Voith Sulzer Papiertech Patent | Process to apply a liquid or paste coating to the surface of a wet paper or cardboard web |
| US6399185B1 (en) * | 1998-10-30 | 2002-06-04 | Timothy D. Cathey | Vegetation substrate |
| US20020096278A1 (en) * | 2000-05-24 | 2002-07-25 | Armstrong World Industries, Inc. | Durable acoustical panel and method of making the same |
| US6443256B1 (en) * | 2000-12-27 | 2002-09-03 | Usg Interiors, Inc. | Dual layer acoustical ceiling tile having an improved sound absorption value |
| US6524504B2 (en) * | 2001-01-04 | 2003-02-25 | Masonite Corporation | Method of producing cellulosic article having increased thickness, and product thereof |
| US6755938B2 (en) * | 2001-08-20 | 2004-06-29 | Armstrong World Industries, Inc. | Fibrous sheet binders |
| US6919132B2 (en) * | 2003-08-07 | 2005-07-19 | Awi Licensing Company | Fiberboard panel having improved acoustics and durability |
| ITFI20040102A1 (en) * | 2004-04-29 | 2004-07-29 | Guglielmo Biagiotti | METHOD AND DEVICE FOR THE PRODUCTION OF TISSUE PAPER |
| FI20051243L (en) * | 2005-12-02 | 2007-06-03 | Esa Silfverhuth | Coating mixture and process for its production |
| US7703243B2 (en) * | 2006-02-13 | 2010-04-27 | Usg Interiors, Inc. | Ceiling tile construction |
| US8309231B2 (en) | 2006-05-31 | 2012-11-13 | Usg Interiors, Llc | Acoustical tile |
| US20080148665A1 (en) * | 2006-12-21 | 2008-06-26 | Yonash Richard F | Ceiling tiles made of rigid pvc |
| US7879433B1 (en) | 2007-03-09 | 2011-02-01 | Awi Licensing Company | Acoustical panel and method of making such panel |
| JP5136203B2 (en) * | 2008-05-20 | 2013-02-06 | 京セラドキュメントソリューションズ株式会社 | Image forming system |
| EP2679690A1 (en) | 2009-06-23 | 2014-01-01 | American Process, Inc. | Process for producing alcohol and other bioproducts from biomass used in thermal conversion to energy and stepwise enzymatic hydrolysis process for cellulosic fiber |
| ES2613640T3 (en) * | 2009-10-02 | 2017-05-25 | Unifrax I Llc | Ultra light weight insulation board |
| US8028803B1 (en) * | 2010-04-13 | 2011-10-04 | Usg Interiors, Inc. | Molding a lightweight cast acoustical product |
| US8536259B2 (en) | 2010-06-24 | 2013-09-17 | Usg Interiors, Llc | Formaldehyde free coatings for panels |
| US8383233B2 (en) | 2010-12-22 | 2013-02-26 | Usg Interiors, Llc | Ceiling tile base mat |
| USD674123S1 (en) | 2011-10-25 | 2013-01-08 | Empire West, Inc. | Ceiling tile |
| US9896807B2 (en) * | 2015-09-25 | 2018-02-20 | Usg Interiors, Llc | Acoustical ceiling tile |
| CN109071346B (en) | 2016-04-04 | 2022-06-14 | 菲博林科技有限公司 | Compositions and methods for providing increased strength in ceiling, floor and building products |
| US9796635B1 (en) | 2016-06-22 | 2017-10-24 | Usg Interiors, Llc | Large diameter slag wool, composition and method of making same |
| US20180079691A1 (en) | 2016-09-20 | 2018-03-22 | Usg Interiors, Llc | Silicate coating for improved acoustical panel performance and methods of making same |
| US10208477B2 (en) | 2016-10-20 | 2019-02-19 | Usg Interiors, Llc | Veil finishing process |
| US10094614B2 (en) | 2016-12-14 | 2018-10-09 | Usg Interiors, Llc | Method for dewatering acoustical panels |
| US10464846B2 (en) * | 2017-08-17 | 2019-11-05 | Usg Interiors, Llc | Method for production of acoustical panels |
| US11753550B2 (en) | 2018-06-14 | 2023-09-12 | Usg Interiors, Llc | Borate and silicate coating for improved acoustical panel performance and methods of making same |
Family Cites Families (21)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2732295A (en) * | 1956-01-24 | Mftrnn of maktivr mfvfp at | ||
| US2077720A (en) * | 1935-05-28 | 1937-04-20 | Johns Manville | Felted product and method of making the same |
| US2702241A (en) * | 1950-10-07 | 1955-02-15 | Hawley Products Co | Glass fiber material |
| US2773764A (en) * | 1954-04-22 | 1956-12-11 | Armstrong Cork Co | Mineral fiber product |
| BE568617A (en) * | 1957-06-18 | 1900-01-01 | ||
| US3093533A (en) * | 1960-02-01 | 1963-06-11 | Wood Conversion Co | Production of fiberboard containing mineral fiber |
| US3250633A (en) * | 1962-01-17 | 1966-05-10 | Celotex Corp | Molded mineral fiber acoustical tile |
| US3379608A (en) * | 1964-01-16 | 1968-04-23 | United States Gypsum Co | Water-felted mineral wool building and insulation product including nonfibrous cellulose binder |
| JPS4926509B1 (en) * | 1970-07-29 | 1974-07-09 | ||
| US3736163A (en) * | 1971-02-02 | 1973-05-29 | Fibreboard Corp | Fiber reenforced insulating segments |
| US4153503A (en) * | 1973-04-02 | 1979-05-08 | Armstrong Cork Company | Method of wet-forming mineral fiberboard product having damage-resistant overlay |
| US4024014A (en) * | 1975-12-15 | 1977-05-17 | Conwed Corporation | Non-combustible hardboard sheet |
| JPS52145424A (en) * | 1976-05-29 | 1977-12-03 | Nitsukaboodo Kk | Method of coating primer on glass fiber plate for decoration |
| FR2365131A1 (en) * | 1976-09-17 | 1978-04-14 | Thomson Csf | RADAR ECHO PRESENCE DETECTION DEVICE, AND PULSE RADAR SYSTEM INCLUDING SUCH A DEVICE |
| JPS5365321A (en) * | 1976-11-24 | 1978-06-10 | Daiken Trade & Industry | Manufacture of mineral fiber plate |
| US4217380A (en) * | 1977-06-02 | 1980-08-12 | The Celotex Corporation | Process for producing a raised embossed effect |
| US4263093A (en) * | 1979-09-20 | 1981-04-21 | Armstrong Cork Company | Method for retaining textured surface of pressed ceiling board |
| US4698257A (en) * | 1982-11-08 | 1987-10-06 | The Celotex Corporation | Wet-end molded product |
| CA1213768A (en) * | 1982-11-08 | 1986-11-12 | Celotex Corporation (The) | Wet-end molding method and molded product |
| US4608108A (en) * | 1982-11-08 | 1986-08-26 | The Celotex Corporation | Wet-end molding method and molded product |
| JPS625847A (en) * | 1985-07-02 | 1987-01-12 | 大建工業株式会社 | Mineral substance fiber board |
-
1988
- 1988-06-23 US US07/210,446 patent/US4911788A/en not_active Expired - Lifetime
-
1989
- 1989-06-19 DE DE1989613824 patent/DE68913824T2/en not_active Expired - Lifetime
- 1989-06-19 EP EP19890111131 patent/EP0347809B1/en not_active Expired - Lifetime
- 1989-06-22 CA CA 603670 patent/CA1328046C/en not_active Expired - Lifetime
- 1989-06-22 KR KR1019890008616A patent/KR100196232B1/en not_active IP Right Cessation
- 1989-06-23 JP JP16245589A patent/JP2871728B2/en not_active Expired - Lifetime
Also Published As
| Publication number | Publication date |
|---|---|
| US4911788A (en) | 1990-03-27 |
| KR910001177A (en) | 1991-01-30 |
| DE68913824D1 (en) | 1994-04-21 |
| KR100196232B1 (en) | 1999-06-15 |
| EP0347809B1 (en) | 1994-03-16 |
| JP2871728B2 (en) | 1999-03-17 |
| EP0347809A1 (en) | 1989-12-27 |
| DE68913824T2 (en) | 1994-10-27 |
| JPH02243575A (en) | 1990-09-27 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CA1328046C (en) | Method of producing acoustical mineral fiberboard | |
| US5071511A (en) | Acoustical mineral fiberboard | |
| US4608108A (en) | Wet-end molding method and molded product | |
| EP0347810B1 (en) | Acoustical mineral fiberboard and method of manufacturing same | |
| CA2320593C (en) | Method and apparatus for producing an inorganic foam structure for use as a durable acoustical panel | |
| US6780356B1 (en) | Method for producing an inorganic foam structure for use as a durable acoustical panel | |
| EP1016757B1 (en) | Multiple layer nonwoven mat, laminate made therefrom and method of making the mat | |
| US6616804B2 (en) | Durable acoustical panel and method of making the same | |
| EP1345864B1 (en) | A dual layer acoustical ceiling tile having an improved sound absorption value | |
| US4153503A (en) | Method of wet-forming mineral fiberboard product having damage-resistant overlay | |
| HU220366B (en) | A gypsum/cellulosic fiber acoustical tile composition | |
| US5107629A (en) | Texturing of acoustical mineral fiberboard with wheel blast machine | |
| JPS6159259B2 (en) | ||
| US6268042B1 (en) | High strength low density board for furniture industry | |
| EP0108381A1 (en) | Wet-end molding method and molded product | |
| US3042577A (en) | Surface treatment of wet felts | |
| JPS6039525B2 (en) | Manufacturing method for fiber reinforced board products | |
| US3573083A (en) | Surface-layered felted fiber substrate and method of producing same | |
| JPH0242958B2 (en) | ||
| US4183886A (en) | Chemical method for embossing a ceramic acoustical product | |
| JP3365189B2 (en) | Manufacturing method of inorganic plate | |
| EP0427274A1 (en) | Texturing of acoustical mineral fiberboard with wheel blast machine | |
| WO2023004288A1 (en) | High acoustic and low density basemat | |
| AU3342301A (en) | Method and apparatus for producing an inorganic foam structure for use as a durable acoustical panel | |
| JPH0154166B2 (en) |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKEX | Expiry |
Effective date: 20110329 |