MXPA95000732A - A composition of antisonous thickness based on cellulose defibs / y - Google Patents

Abstract

The present invention relates to a free composition of wetted mineral wool, suitable for producing, in a water-felting process, sound-insulating tiles essentially consisting of gypsum, cellulose fibers, a lightweight aggregate and a binder, wherein on a solid basis dry, there is at least about 15% by weight of gypsum and at least about 13% by weight of gypsum and at least about 13% by weight of cellulosic fibers

Description

IMPROVEMENTS IN A COMPOSITION OF AIITISONORA STRAND BASED ON CELLULOSIC FIBERS / INVENTOR PLASTER: MIRZA A. BAIG, American citizen, residing at: 9415 Meadow Lane, Des Plaines, Illinois 60016, E.U.A.

CAUSAHIENT: USG INTERIORS, INC., A North American Society, organized and existing in accordance with the Laws of the State of: Delaware, E.U.A., domiciled at: 101 S. Wacker Drive, -Chicago, Illinois, E.U.A.

EXCERPT OF THE INVENTION A composition of sound-insulating tiles based on a composition of cellulosic fibers / gypsum, which can replace all or a portion of the mineral canvas normally present in acoustic ceiling tiles. The composition of cellulose fibers / gypsum is combined with a light weight aggregate and a binder to form a composition that is used in a water felting process to make panels and tiles from acoustic ceilings. A preferred source of cellulosic fiber is a composite material of cellulosic fibers / gypsum which is prepared by mixing the gypsum and the cellulosic fiber material with sufficient water to form a diluted sludge which is then heated under pressure to calcinate the cellulose fiber. gypsum, converting it to a calcium sulfate alfaheiriihidrata do. The resulting composite material comprises cellulosic fibers physically entangled with calcium sulfate crystals. Another source of both cellulosic and gypsum fibers is fibreboard pressed with gypsum (waste scrap.) Expanded perlite is the preferred material as a lightweight aggregate FIELD OF THE INVENTION This invention relates to sound-insulating tile compositions useful for making sound-insulating tiles and panels for roofing applications. relates to acoustic tile compositions based on a gypsum / gypsum fiber composition, which can replace all or a portion of the mineral wool normally present in acoustic ceilings The invention also relates to an expanded perlite / fiber composition cellulosic / novel plaster that is used in a process of felting with water, to manufacture panels and tiles for acoustic ceilings BACKGROUND OF THE INVENTION The water felting of diluted aqueous dispersions of mineral wool and lightweight aggregate, is a commercial process for To make tiles for acoustic ceilings In this process, a wool dispersion The mineral, light weight aggregate, binder and other ingredients as desired or necessary are circulated in a foraminous moving support wire, such as that of a Fourdrinier or Oliver mat forming machine for dehydration. The dispersion is first dehydrated by gravity and then with vacuum suction means; the wet mat is dried in heated convection drying ovens, and the dried material is cut at desired dimensions and optionally overcoated, such as with paint to produce panels and acoustic ceiling tiles. For many years, acoustic ceiling tile has also been produced by a modeling or wet pulp molding process, as described in US Pat.

No. 1,769,519. In accordance with the teachings of this patent, a molding composition comprising granulated mineral wool fibers, fillers, colorants and a binder, in particular a starch gel, is prepared to mold or model the body of the tile. This mixture or composition is placed in convenient trays that have been covered with paper or a thin metal sheet and then the composition is flushed to a desired thickness with a roller or furring rod. A decorative surface, such as elongated fissures can be provided by the roller or furring bar. The trays filled with the mineral wool composition or pulp are then placed in an oven to dry or cure the composition. The dried leaves are removed from the tray if they can be treated on one or both sides to provide smooth surfaces, to obtain the desired thickness and avoid warping or twisting. The sheets are then cut into tiles of a desired size. In my U.S. patent No. 5,320,677, issued on June 14, 1994, I described a composite material and method to produce it, where ground gypsum is calcined under pressure in a sludge diluted in the presence of cellulosic fibers. Gypsum milled without calcining and the cellulose fibers are mixed together with enough water to form a diluted sludge that is then heated under pressure to calcinate the gypsum, converting it to calcium sulfate alpha hemihydrate. The resulting co-calcined material consists of the cellulosic fiber physically entangled with calcium sulfate crystals. This entanglement not only creates a good bond between calcium sulfate and cellulosic fibers, but also prevents migration of calcium sulfate away from the cellulosic fiber, when the alpha hemihydrate is rehydrated subsequently to the dihydrate (gypsum). The co-calcined gypsum / cellulose fiber material can be dried immediately before cooling to provide a stable rehydratable alpha hemihydrate compound for later use. Alternatively, the co-calcined material can be converted directly into a usable product by separating excess water that is not required for rehydration, forming the composite particles into a desired structure or shape, and then rehydrating the particles to a composite material. cellulose fibers / plaster, hardened and stabilized. Acoustic mineral wool tiles are very porous, which is necessary to provide good sound absorption. The prior art (U.S. Patent Nos. 3,498,404, 5,013,405 and 5,047,120) also disclose that mineral fillers such as expanded perlite can be incorporated into the composition. to improve sound absorption properties and to provide light weight. An object of this invention is to provide a sound-insulating tile composition in which some or all of the mineral wool is replaced by a cellulose / gypsum fiber composition. Another object of this invention is to provide a mineral wool-free sound-insulating tile composition, which has acoustic properties comparable to mineral wool tiles made by a water felting process. A further objective of this invention is to provide an anti-noise tile composition that essentially consists of gypsum, cellulosic fibers, expanded perlite and a binder. These and other objectives will be apparent to persons with skill in the art in view of the description that follows. SUMMARY OF THE INVENTION It has been found that a composition consisting essentially of gypsum, cellulose fiber, expanded perlite and a binder, can be used to produce acoustic ceiling tiles and panels, using equipment and procedures currently used in a water felting process. produce tiles and acoustic panels. The composition may also contain a small amount of mineral wool or may not contain mineral wool The dry product can be formed into tiles or panels that have comparable acoustic properties with commercially available sound-deadening tiles. A particularly preferred composition employs a cellulosic / gypsum composite material in which the gypsum and the cellulosic fiber are co-calcined under pressure to physically intertwine the cellulosic fiber with the calcium sulfate crystals. The sound-deadening tiles made from the compositions of this invention have acceptable physical properties for use in suspended ceiling systems. DETAILED DESCRIPTION OF THE INVENTION The anti-noise tile compositions of this invention are based on employing a cellulosic / gypsum fiber composition as a replacement, either partial or complete, for mineral wool in the manufacture of roof panels or tiles using a felting process with Water. In addition to gypsum and cellulosic fiber, the composition also contains expanded perlite and a binder, and may also contain other additives such as clay, flocculant and surfactant, and usually included in acoustic ceiling tile formulations. As noted above, the composition may contain some mineral wool (in reduced amount), however it has been found that the compositions of this invention can be used to produce mineral wool-free sound-insulating panels and tiles.

One of the key ingredients in the novel acoustic tile composition of this invention is gypsum (calcium sulfate dihydrate). The solubility of the gypsum in the processing sludge allows the gypsum to function as a flocculant in the formulation. This flocculation function provides a uniform distribution of fine particles (clay, gypsum, perlite and starch) on the wet mat during processing. In the absence of this flocculating action, the fine and high density particles tend to migrate to the bottom of the mat during processing, which adversely affects the discharge of water from the wet mat. The presence of gypsum in the formulation also provides deagglomeration of mineral fibers (if present) and sludge from cellulose fibers. The deagglomeration or dispersing function that is provided by the gypsum, allows the processing of a higher mud consistency (% solids) that reduces the amount of water to be removed from the mat and increases the production speed. In addition to the processing benefits that are provided by the plaster, it also improves the properties of the soundproofing tile. The presence of gypsum, which replaces the mineral wool fiber (partial or complete) in the formulation, provides a significant improvement in the surface hardness of the panels. The improved surface hardness of the roof panels also provides good surface texture (eg cracking, drilling, etc.). The superior level of fibers of Cellulose can also contribute to these improvements. The surface smoothness of the acoustic panels can also be improved by the plaster, whereby sanding the surface after drying can be eliminated. It has also been found that the cellulosic / gypsum fiber formulation does not spring back to its original position (swell) after wet pressing and drying operations, as compared to formulations containing mineral fiber. The non-swelling characteristics of the mineral wool free ceiling tile indicate that the dry mat thickness can be determined or controlled precisely during the wet pressing operation, thereby eliminating the need for a filler or sanding dry mat to control the thickness to finish the panel. Another key ingredient in the novel anti-noise tile compositions of this invention is cellulosic fiber. Various types of cellulosic fibers have been evaluated in these compositions. It is well known to use newsprint in anti-noise tile formulations and both hydroponic paper and hammer crusher have been evaluated in these compositions. Wood fibers can also be used as the source of cellulosic fibers, however, it has been found that ceiling tiles made with wood fibers, whether softwood or hardwood, are more difficult to cut with a blade on the site of installation.

A preferred source of the cellulosic fiber is a composite cellulose fiber / gypsum material that has been co-calcined as described in U.S. Pat. No. 5,320,677. As described therein, said description is incorporated herein by reference, the gypsum without calcining and either wood or paper fibers are mixed together with enough water to form a diluted sludge which is then heated under pressure to calcine the gypsum, converting it to a calcium sulfate alpha-hemihydrate. The resulting composite material comprises cellulosic fibers physically entangled with calcium sulfate crystals. The composite material can be dried immediately before cooling, to provide a stable, but rehydratable, calcium sulfate hemihydrate, or the composite sludge can be used directly to make the sound-insulating tile. It has been found that the use of co-calcined paper / gypsum composite material provides an anti-noise tile composition that has higher mat solids retention and better wet overlap resistanceHowever, it is slower to discharge and harder to cut with a blade than plaster-made tiles physically mixed with paper fibers (newsprint). Another source of both cellulosic and gypsum fibers is fiber board pressed with waste plaster (waste). It has been found that the pressed fiber board can be ground into gypsum particles and paper fibers that can be physically mixed with the other ingredients in a acoustic formulation, to provide a useful sludge in a process of felting with water to prepare a ceiling tile. Alternatively, the crushed waste chipboard can be used as a feed material in a co-calcining process and the co-calcined composite paper / gypsum material can be used in a formulation to prepare a tile. of ceiling by felted with water. A third key ingredient in the novel anti-noise tile compositions of this invention is expanded perlite. This is not a novel ingredient, since it is well known in the art to use expanded perlite in anti-noise tile compositions. The expanded perlite provides porosity in the composition, which improves the acoustic properties. It has been found that a medium-grade expanded perlite provides sufficient porosity and acceptable texture. An expanded perlite material commercially available from Silbrico Corporation under the designation perlite 3-S, has been found acceptable. The medium-grade expanded perlite contains pearlite particles that are similar in size to granulated mineral wool. The fourth key ingredient, which is also not novel in acoustic compositions, is a binder. It is well known to use starch as a binder in sound-insulating tiles based on mineral wool. A starch gel can be prepared by dispersing Starch particles in water and heat the sludge until the starch is fully cooked and the sludge is thickened to a viscous gel. A portion of the cellulosic fibers can be incorporated into the starch sludge before cooking. The cooking temperature of the starch sludge should be checked closely to ensure complete swelling of the starch granules. A representative cooking temperature for corn starch is about 82 ° C (180 ° F) to about 90 ° C (195 ° F). A latex binder can be used instead of the starch or in combination with the starch binder. Many of the latex binders useful in acoustic ceiling formulations are described in U.S. Pat. No. 5,250,153. As stated there, one of the problems with acoustic panels that employ a starch binder is excessive buckling, especially in high humidity conditions. It is well known in the art to use thermoplastic binders (latexes) in anti-noise tiles based on mineral wool. These latex binders can have a glass transition temperature in the range from about 10 ° C to about 110 ° C. Examples of latex binders include polyvinyl acetate, acrylic emulsion / vinyl acetate, vinylidene chloride, polyvinyl chloride, styrene / acrylic copolymer and carboxylated butadiene / styrene.

In addition to the four main ingredients, the acoustic compositions of this invention may also contain inorganic fillers such as clay, surfactants and flocculants. These ingredients are well known in the anti-noise tile compositions. The sound-deadening tile compositions of this invention essentially consist of gypsum, cellulose fiber, expanded perlite and a binder which may be present in the following amounts: Ingredient Percent in Weight Plaster 20-40% Cellulose Fibers 15-25% Perlite Expanded 25-50% Binder 5-15% Example 1 Tiles are prepared for acoustic ceilings, to evaluate replacing the mineral fiber in a formulation felted with conventional water and the process. The mineral fiber was replaced with gypsum and wood fibers at levels of 25 to 50, 75 and 100%. Some tiles were made where gypsum and wood fiber were co-calcined before incorporation into the acoustic formulation and other tiles were made where gypsum and wood fiber were simply physically mixed with the other ingredients without co-calcining . The ratio of gypsum to wood fibers was 85: 15% by weight in all formulations.

The wood fibers were softwood obtained from the International Papel Pilot Rock installation. The expanded perlite was grade 3-S from Silbrico Corporation. In addition to the wood fibers, cellulose fibers were also supplied by shredded paper. 1500 grams of water were added to the required amount of newsprint and mixed at high speed in an industrial mixer. Cornstarch was used as binder. The flocculant was GEN DRIV 162, and 4 grams of flocculant were added to 1000 milliliters of deionized water and mixed for less than two hours. The surfactant was NEODOL 25-3. The gypsum and the wood fibers were calcined together in a reactor at a consistency of 15% solids. The calcination was carried out according to the procedures described in the U.S. patent. No. 5,320,677. After co-calcining, the excess water was removed from the composite by applying vacuum, after which the composite material was allowed to hydrate completely to calcium sulfate dihydrate (gypsum) before drying at 49 ° C (120 ° F) overnight at constant weight. Another batch of gypsum / wood fibers was co-calcined as described above, except that after removal of excess water by vacuum, the composite was immediately dried at 121 ° C (250 ° F) for 30 minutes to avoid hydration, followed by drying at 49 ° C (120 ° F) overnight at constant weight. In this composite material, calcium sulfate was in the hemihydrated form. After drying, the Gypsum / wood fiber composites in both dihydrate and hemihydrate forms were decomposed in a double sheet mixer prior to incorporation into the sound-deadening composition. In the process of felting with water used to produce acoustic tiles, the feed sludge during the formation of a mat is maintained at 4% solids. This consistency of 4% solids was also used to produce the control tile that contains 100% mineral fibers and no gypsum / wood fibers. The following formulations (in percent by weight) were used to produce the tiles: TABLE 1 Experimental Control 100% MF 75% MF 50% MF Ingredient 0% G / WF 25% G / WF 50% G / WF 75% G / WF 100% G / WF Mineral Fibers 37.58 28.18 18. .79 9 .39 0 Plaster 0 7.98 15, .97 23, .9 31.94 Wood Fibers 0 1.41 2, .82 4, .22 5.64 Perlite 34.83 34.83 34, .83 34, .83 34.83 Expanded Paper 15.91 15.91 15.91 15.91 15.91 Total Fiber Periodic 15.91 17.32 18.73 20.13 21.55 Cellulosic Clay CTS-1 3.54 3.54 3.54 3.54 3.54 Starch 8.01 8.01 8.01 8.01 8.01 TABLE 1 (Cont.) Experimental Control 100% MF 75% MF 50% MF Ingredient 0% G / WF 25% G / WF 50% G / WF 75% G / WF 100% G / WF Flocculant 0.06 0.06 0.06 0.06 0.06 Surfactant 0.08 0.08 0.08 0.08 0.08 Evaluation procedures include pressboard formation and processing, discharge time, pressing, drying and the effect on the physical properties of the sound-insulating tiles. In general, there was no significant difference in the formation of the mat. After mixing all the ingredients to a consistency of 4% solids, the sludge was emptied into a Tappi Box and mixed gently with a 30.48 x 30.48 cm (12 x 12 inch) perforated plunger to uniformly disperse the solids. After the mat was formed in the box, vacuum was applied to the wet mat. It took approximately 30 seconds for the vacuum to reach 50.8 cm (20 inches) of mercury, after which the vacuum was released and two discharge times were recorded. The first discharge time was when the water completely disappeared from the surface of the mat and the second discharge time was when the indicator was decreased to 12.7 cm (5 inches) of mercury. At that stage, the vacuum system was interrupted, and the wet mat was removed from the Tappi Box and weighed before pressing.

Vacuum dehydrated boards were pressed to a thickness of 1,588 cm (5/8 inch) and dried. The wet mats were dried in an oven at 316 ° C (600 ° F) for 30 minutes and subsequently, the oven temperature was reduced to 177 ° C (350 ° F) and the tiles were dried for an additional 90 minutes. Before drying, a study was conducted to determine if the wet mats could dry without calcining the plaster. It was determined that the mats could be dried in an oven as described above, without calcining the gypsum to hemihydrate or anhydrite. After drying, all test specimens were cut and subjected to conditions of 24 ° C (75 ° F) / 50% at least for 24 hours before testing. The specimens were tested for the following: 1) density, thickness and MOR resistance 2) acoustic properties (NRC) 3) dimensional stability (water absorption) The following results were recorded (results are based on an average of 4 specimens in each) game unless otherwise indicated: TABLE 1A Gypsum and Wood Fibers (No Co-Calcination) Thickness Discharge After% Water% Water Vacuum Time Retreat Retreat (is.) Cm (in.) (Vacuum) (press) Control (100% MF) * 4.3 -11.4 2,619 80.47 80.93 (1,031) 75% MF & 25% G / WF 4 - 11 2.54 80.60 82.27 (1,000) 50% MF & 50% G / WF 4 - 11 2.54 80.55 81.85 (1,000) 25% MF & 75% G / WF 5.5-12.5 2.461 81.68 82.27 (0.969) 100% G / WF ** 7.3-13 2.382 81.52 82.69 (0.938) TABLE 1A (Continued) Gypsum and Wood Fibers (No Co-Calcination) Thickness Density% of Dry Board Board Water Dry Dry cm (in.) (A / cc (Ib. / Ft3) Control (100% MF) * 79.77 1.613 (0.635) .1603 (10.02) 75% MF & 25% G / WF 79.89 1.514 (0.596) .1579 (9.87) 50% MF & 50% G / WF 80.52 1.504 (0.592) .1579 (9.87) TABLE 1A (Continued) Gypsum and Wood Fibers (No Co-Calcination) Thickness Density% Water Board Dry Total Board Dried cm (in.) (G / cc (Ib. / Ft3! % MF & 75% G / WF 80.13 1.480 (0.583) .1598 (9.99) 100% G / WF ** 79.97 1.478 (0.582.1592 (9.95) TABLE 1A (Continued) Gypsum and Wood Fiber (No Co-Calcination)% Loss of Weight Loss During Additional Processing% (gypsum) Control (100% MF) * 5.01 75% MF & 25% G / WF 10. 74 5.58 50% MF & 50% G / WF 11. 45 6.45 25% MF & 75% G / WF 11. 80 6.80 100% G / WF ** 12. 20 7.20 * 2 Specimens ** 3 Specimens TABLE IB Composition Dihydrate (Co-Calcinate) Thickness Discharge After% Water% Water Vacuum Time Retired Retired (sec.) Cm (in.) (Empty) (press) Control 4.4-11.4 2.700 (1.063) 80.44 82.11 75% MF & 25% GWF 4.6-10.9 2.54 (1,000) 78.27 80.58 50% MF & 50% GWF 5-11 2.382 (0.938) 81.24 82.41 25% MF & 75% GWF *** 5.7-11 2.382 (0.938) 79.68 82.03 100% GWF 7-11 2.382 (0.938) 82.24 83.34 TABLE IB (Continued) Composition Dihydrate (Co-Calcinate) Thickness Density% Water Board Dry Total Board Dry Dry cm (in.) (G / cc (Ib. / Ft3) Control 7 788 ..7766 1 1..660022 ((00..663322)) .1574 (9.87) 75% MF & 25% GWF 8 800 .. .5577 1 1..559933 ((00..662277)) .1588 (9.93) 5 500 %% MMFF & S 5500 %% GGWWFF 7 7 7999 .., .888333 1 1..550011 ((00..559911)) .1568 (9.80) 80, .77 1.499 (0.590) .1547 (9.67) 100% GWF 7 799. .9900 1 1..442200 ((00..555599)) .16 (10.00) TABLE IB (Continued) Composition Dihydrate (Co-Calcinate)% of Weight Loss Weight Loss During Additional Processing% (gypsum) Control (100% MF) * 5.51 75% MF & 25% G / WF 9.74 4.2 50% MF & 50% G / WF 12.26 6.75 25% MF & 75% G / WF 13.40 7.89 100% G / WF ** 15.23 9.72 *** 3 Specimens TABLE 1C Compound Hemihydrate (Co-Calcined) Thickness Discharge After% Water% Water Empty Time Withdrawal Withdrawal (be.) Cm ( in.) (Empty) (press) Control (100% MF) * 4.6 - 11 2.54 (1.0) 80.43 81.31 75% MF & 25% G / WF 4.8 - 10.4 2.54 (1.0) 80.93 81.46 50% MF & 50% G / WF 5.6 - 11.4 2.54 (1.0) 79.99 81.57 % MF & 75% G.WF 6.8 - 11.3 2.54 (1.0) 81.98 82.63 100% G / WF 9.3 - 13.8 2.54 (1.0) 82.9 83.87 TABLE 1C (Continued) Compound Hemihydrate (Co-Calcined) Thickness Density% Water Board Dried Dry Total Board cm (in.) (G / cc (Ib. / Ft3) Control (100% MF) * 79.88 1,585 (0.624) .1590 (9.94) 75% MF & 25% G / WF 80.87 1.529 (0.602) .1557 (9.73) 50% MF & 50% G / WF 81.58 1.514 (0.596) .1502 (9.39) 25% MF & 75% G.WF 81.06 1.455 (0.573) .1517 (9.48) 100% G / WF 79.86 1.450 (0.571) .1502 (9.39) TABLE 1C (Continued) Compound Hemihydrate (Co-Calcinate)% Weight Loss Weight Loss During Additional Processing% (plaster) Control (100% MF) * 5.86 75% MF & 25% G / WF 11.24 5.38 50% MF & 50% G / WF 14.97 9.12 25% MF & 75% G.WF 17.58 11.72 100% G / WF 18.87 13.02 TABLE ID Density, Thickness, Resistance (MOR) No. of% Thickness Samples MF / WF cm (inch) Control 29 100 0 1,593 (0.627) (100% MF) 10 75 25 1,524 (0.600) Plaster / 10 50 50 1.53 (0.602) Wood (No 10 25 75 1,501 (0.591) Co-Calcin. ) 9 0 100 1,498 (0.590) 10 75 25 1.64 (0.630) Compound 10 50 50 1,506 (0.593) Dihydrate (Co-Calcin.) 6 25 75 1,501 (0.591) 10 0 100 1.42 (0.559) 10 75 25 1.529 (0.602) Compound 10 50 50 1,516 (0.597) Hemihydrate (Co-Calcin.) 10 25 75 7 0 100 1,443 (0.568) TABLE ID (Continued) Density, Thickness, Resistance (MOR) Density MOR (g / cc (lb / ft3) kg / cm2 (psi) Control .16 (10.05) 3.73 (53) (100% MF) 158 (9.86) 3.87 (55) Plaster / 159 (9.95) 3.94 (56) Wood (No 16 (10.05) 4.43 (63) Co-Calcin.) 162 (10.15) 5.85 (83) 16 (10.05) 3.37 (48) Compound 159 (9.99) 4.01 (57) Dihydrate (Co-Calcin.) 154 (9.64) 4.01 (57) .163 (10.22) 4.43 (63) .156 (9.76) 4.07 (58) Compound 150 (9.39) 3.87 (55) Hemihydrate (Co-Calcin.) 151 (9.46) 4.01 (57) 149 (9.32) 3.73 (53) TABLE 1E Acoustic Properties Compound Dihydrate Frequency 250 500 1000 2000 NRC Hz Hz Hz Hz (avg.) Control Drop in Db 32 27 21.5 22 Absorbance 0.266 0.392 0.546 0.532 0.434 75% MF / 25% GWF Drop in Db 29.5 24 21 21 Absorbance 0.326 0.476 0.562 0.560 0.481 50% MF / 50% GWF Drop in Db 29 24.5 20 19.5 Absorbance 0.332 0.469 0.599 0.606 0.501 % MF / 75% GWF Drop in Db 29.5 22.5 21.5 19.5 Absorbance 0.332 0.518 0.546 0.613 0.502 100% GWF Drop in Db 29 23 18.5 19 Absorbance 0.339 0.503 0.636 0.621 0.525 TABLE 1F Stability Dimensional Compound Dihydrate (Average of 6 Samples)% of Absorption% of Absorption% of Increase of H20 of H20 in Thickness 1 - Hour 4 - Hours 4 - Hours Control 387.96 404.14 - 0.540 75% MF / 25% GWF 386.48 396.15 0.035 50% MF / 50% GWF 390.23 399.90 - 0.412 TABLE 1F (Cont.) Dimensional Stability Dihydrate Compound (Average of 6 Samples) of Absorption% Absorption% H20 Increment of H20 in Thickness 1 - Hour 4 - Hours 4 - Hours % MF / 75% GWF 388.10 400.66 - 0.066 100% GWF 388.61 400.50 - 0.121 The discharge time is not affected when 25% of the mineral fiber is replaced by gypsum and wood fibers; however, the discharge was slightly adversely affected as the level of gypsum / wood fibers increased, especially at 100% hemi-hydrate compound. The thickness of the dehydrated mat decreased slightly when the level of wood / gypsum fibers increased. The difference in moisture content after dehydration under vacuum and pressing was negligible. The thickness of all wet mats was controlled at 1397 cm (0.55 inch) during pressing. It appeared that the wet pressing only controls the thickness of the mat and does not dehydrate the mat. The drying data indicates that some gypsum was filtered through the sieve with excess water during sieve formation and vacuum dehydration. The average weight loss in the control mats was approximately 5.5%, while the loss in weight in the mats containing the fibers of wood / plaster was substantially higher. The plaster settled on the bottom of the mats during the formation of the mat. Dry tiles containing gypsum / wood fibers also buckled slightly and buckling was severe when the mineral fill was completely replaced with gypsum / uncalcined wood fibers. However, there was no buckling in the tiles when replacing the mineral fiber with a hemihydrate or co-calcined dihydrate compound. The MOR resistance of the tiles containing gypsum / wood fibers was comparable with the control, even though the density was slightly lower (probably due to the gypsum lost during the formation of the mat). The thickness of the tiles containing gypsum / wood fibers was lower due to the low specific volume of the gypsum, which does not return elastically during drying as 100% mineral fiber tiles. Duplicate samples of control and experimental tiles with mineral fiber replaced by the wood fiber / gypsum dihydrate compound (co-calcined) were tested for NRC using the impedance tube method. The samples were not punctured, cracked or painted. In general, the NRC ratings for the tiles containing the wood / gypsum fibers were better than the control, especially for the tiles where all the mineral fiber was replaced. In the test for dimensional stability, there was no significant difference in the values for water absorption of 1 and 4 hr. As noted previously, very little water was removed (approximately 2%) of the tiles during wet pressing. Approximately 78% moisture was evaporated during drying, however this produces excessive pores in the tiles. however, during the dimensional stability test water penetrated the pores of the tiles, resulting in high water absorption. Example 2 Gypsum Board of Waste Fibers (Waste) was evaluated as a source of gypsum and paper fibers (co-calcined) in acoustic ceiling tiles. The pressed waste board was ground into small particles. Although some large pieces of paper were present, these were broken during calcination and the agitation required to keep the sludge in suspension during the calcination. The pressed board sludge from gypsum and waste fibers was co-calcined with additional waste paper (hydropulped) with which the sludge consisted of 15% dry weight of paper fibers and 85% by weight of gypsum. This was co-calcined to a consistency of 155 solids and the calcination was carried out as described in U.S. Pat. No. 5,320,677. After calcination, the composite material of paper / gypsum fibers was discharged from the reactor with the gypsum in its hemihydrated form. Two acoustic ceiling tiles were made by dehydrating (emptying) the mud, after mixing with pearlite Expanded and corn starch, and then press the wet mat to remove additional excess water and to control the thickness of the tiles before drying. The tiles were dried at 316 ° C (600 ° F) for 30 minutes, followed by 90 minutes at 343 ° C (650 ° F). The following tables represent the registered MOR formulation and strength: TABLE 2 A Tile No. 1 Tile No. 2 Ingredient Weight (gms.) Weight. % Weight (gms.) Weight% Plaster (hemihydrate) 158.1 39.4 607.8 66.4 Waste Paper 85.9 21.4 167.0 18.3 Expanded Perlite 137.0 34.2 120.0 13.1 Corn Starch 20.0 5.0 20.0 2.2 Consistency of Mud 4 (% solids) TABLE 2 B Thickness MOR Density Sample of Tile cm (inch) q / < C (lbs. / Ft3) kg / cm2 (psi) the 1.605 (0.632) .12 (7.5) 4.78 (68) Ib 1.572 (0.619.12 * 7.5) 4.36 (62) le 1.582 (0.623.118 (7.4) 4.71 (67) Id 1.600 (0.630) .118 (7.4) 5.48 (78) Medium 1,590 (0.626) .119 (7.45) 4.85 (69) 2a 1.575 (0.620 326 (20.4) 11.81 (168) TABLE 2 B (Cont.) Thickness MOR Density Tile Sample cm (inch) g / cc (lbs./ft3) kg / cm2 (psi) 2b 1.638 (0.645) .337 (21.1) 12.58 (179) 2c 1.630 (0.642) ) .328 (20.5) 11.18 (159) 2d 1.633 (0.643) .323 (20.2) 10.83 (154) Medium 1,620 (0.638) .329 (20.6) 11.6 (165) Control (Tile of 1.575 (0.62) .176 (11) 4.57 (65) Typical Mineral Fibers) Tile No. 1 having a density suitable for use as an acoustic ceiling tile also had a MOR comparable to the control. Example 3 Two roof tiles were made using agglomerated gypsum board of ground waste. There were large pieces of paper on the crushed chipboard. Ceiling tiles were produced by replacing agglomerated gypsum board and additional newspaper fibers in a mineral fiber board formulation. The tiles were produced by mixing all the tiles for 3 minutes in a watery sludge (4% solids). After mixing, the sludge formed on a wet mat, dehydrated under vacuum and wet pressed to control the thickness and remove some excess water before drying. The processing was comparable to using a mineral fiber formulation except that the time of download was slightly longer. After drying, there were still large pieces of paper in the tiles. Dry tiles were subjected to 24 ° C (75 ° F) / 50% relative humidity as conditions for at least 24 hours before testing for MOR resistance. The following tables represent the registered MOR formulation and strength: TABLE 3 A Weight Weight Ingredients (grams)% Plaster (waste board) 167,696 41,924 Fiber Paper (waste board) 10,704 2,676 Fiber Paper Periodic (additional) 64.0 16.0 Fiber of Total Paper 74,704 18,676 Expanded Perlite 120 30 Clay (CTS-1) 17.6 4.4 Starch 20 5 Flocculant (Gendriv) 0.06 Surfactant (Neodol 25-3) 0.08 TABLE 3 B Thickness MOR Density Tile Sample cm (inch) q / cc ( lbs. / ft3) kg / cm2 (psi) the 1.468 (0.578) .163 (10.2) 3.23 (46) Ib 1.448 (0.570) .166 (10.4) 3.87 (55) le 1.435 (0.565.166 (10.4) 3.16 (45) TABLE 3 B (Cont.) Thickness MOR Density Sample of Tile cm (pulqada) g / cc (lbs./foot3) kg / cm2 (Psi) Id 1.453 (0.572) .162 (10.1) 3.02 (43) le 1.498 (0.590.166 (10.4) 3.30 (47) Middle 1.460 (0.575) .165 (10.3) 3.30 (47) 2a 1.468 (0.578) .162 (10.1) 3.58 (51) 2b 1,521 (0,599) .163 (10.2) 4.22 (60) 2c 1,493 (0,588) .16 (10.0) 3.37 (48) 2d 1.470 (0.579) .16 (10.0) 3.09 (44) 2e 1.466 (0.577.165 (10.3) 3.52 (50) Middle 1,483 (0.584) .162 (10.1) 3.58 (51) These test data indicate that MOR of these tiles (no co-calcination) was inferior to higher density when compared to the same types of tile (see Example 2) that are produced by co-calcination of the same agglomerated chipboard waste material of plaster. Example 4 Tests were performed to evaluate 100% replacement of mineral wool in a ceiling tile formulation with a gypsum / cellulose fiber (co-calcined) composite material. In order to improve the cutting capacity of the ceiling tile, the gypsum was co-calcined with fine newspaper (hydropulped) instead of wood fibers.

Plaster and 20% by weight of shredded (periodic) paper were calcined according to the procedure described in US Pat. No. 5,320,677. The shredded newspaper was soaked in water overnight, and then gypsum was added and mixed with the paper fiber sludge, at least for 1 hour before calcining the sludge. After calcining, the excess water was removed (vacuum) and then the paper / gypsum fiber composite was dried to hemidrate. The following tables represent the MOR formulations and data recorded: TABLE 4 A Formulation # 1 Formulation # 2 Ingredients Weight (gms.)% In Weight Weight (gms.)% In Weight Plaster (calcined) 142.3 37.2 142.3 35.4 Paper Fibers (calcined) 30 7. 8 30 7. 5 Newspaper 40 10. 5 40 9. 9 Expanded Perlite 150 39. 2 150 37. 3 Corn Starch 20 5. 2 40 9. 9 Mineral Fibers 0 0 Clay 0 0 Mud Solids 7.8 8.1 TABLE 4 A (Continued) Formulation # 3 Control Ingredients Weight (gms.)% In Weight Weight (gms.)% In Weight Plaster (calcined) 142.3 36.2 0 Paper Fibers (calcined) 30 7.65 0 Newsprint 50 12.75 16.0 Expanded Perlite 150 38.2 30.0 Corn Starch 20 5.1 5.0 Mineral Fibers 0 44.6 Clay 0 4 Sludge Solids 7.4 Flocculant and standard surfactant were used in all formulations. TABLE 4 B Esp «.sor Density Sample No. cm (pig.) Q / cc: (lbs. - / ft3) Form. the 1.618 (0.637) .152 (9.5) Ib 1.600 (0.630) .147 (9.2) le 1.615 (0.636) .147 (9.2) Id 1.623 (0.639) .149 (9.3) le 1.733 (0.682) .155 (9.7) Medium 1.638 (0.645) .150 (9.4) Form 2a 1.59 (0.626) .155 (9.7) TABLE 4 B (Cont.) Thickness Density Sample No. cm (: pig.) g / cc: (lbs. / ft3) 2b 1.60 (; 0.630) .156 (9.8) 5 2c 1.615 (0.636) .156 (9.8) 2d 1.656 (0.652) .162 (10.1) Medium 1.615 (0.636) .158 (9.8) Form 3a 1,592 (0,627) .156 (9.8) 0 3b 1,577 (0.621) .153 (9.6) 3c 1,572 (0.619) .152 (9.5) 3d 1,588 (0.625) .153 (9.6) 3e 1,658 (0.653) .158 (9.9) ) Medium 1.597 (0.629) .155 (9.7) .5 Control at 1.506 (0.593) .181 (11.3) b 1.499 (0.590) .181 (11.3) c 1.514 (0.596) .181 (11.3) d 1496 (0.589). 182 (11-4) e 1,552 (0.611) .186 (11.6) ¡0 Medium: L.514 (0. 596) .182 (11.4) TABLE 4 B (Continued) MOR Burden at Break Sample No. kg / cm2 (psi.) Kg / (lbs.) Form. 1,884 (30.2) 1,852. (4.08) > 5 Ib 1.877 (26.8) 1.612 (3.55) TABLE 4 B (Continued) MOR Load to Break Sample No. kg / cm2 (psi.) Kg / (lbs.) Le 1652 (23.5) 1.439 (3.17) Id 1.877 (26.7) 1.648 (3.63) le 2.137 (30.4) 2.138 (4.71) Medium 1.933 (27.5) 1.739 3.83 ) Form 2a 2,664 (37.9) 2.247 4.95) 2b 2.488 (35.4) 2.125 4.68) 2c 2.468 (35.1) 2.147 4.73) 2d 3.058 (43.5) 2.799 6.16) Medium 2.671 (38.0) 2.329 5.13) Form 3a 2.875 (40.9) 2.433 5.36) 3b 2.186 (31.1) 1.816 4.00) 3c 2.116 (30.1) 1.748 3.85) 3d 2.242 (31.9) 1.888 '4.16) 3e 3.121 (44.4) 2.864 6.31) Medium 2.51 (35.7) 2.152 4.74) Control to 3.48 (49.5) 2.633 (5.80) b 3.297 (46.9) 2.470 (5.44) c 3.255 (46.3) 2.488 (5.48) d 3.663 (52.1) 2.733 (6.02) e 3.38 (48.1) 2.715 (5.98) TABLE 4 B (Continued) MOR Load at Breakdown Sample No. kg / cm2 (psi.) Kg / (lbs.) Medium 3.417 (48.6) 2.606 (5.74) After testing the samples for MOR resistance, they were also tested for capacity of cutting using a chipboard knife. The control tiles (16% of newsprint) are cut with cleanliness, however the plaster tiles / paper fibers (17.4% of newsprint) had very rough cuts. Example 5 Additional tests were carried out to determine the effect on the tile cutting capacity, by reducing the paper fiber content in the formulation and also increasing the starch content to maintain the dry tile strength. It is considered that reducing the fiber content of paper will adversely affect the strength. The experimental ceiling tiles were made using gypsum and paper fiber (newsprint) co-calcined. After calcining a slurry of 80% gypsum and 20% periodic paper (15% solids), the solid was dehydrated (vacuum) and dried as a hemihydrate composite. The hemihydrate compound was evaluated as a replacement for 100% of the mineral fiber. The shredded newspaper was soaked in water overnight and the next day mixed with gypsum to form the sludge at 15% solids for calcination.

The following tables represent the formulation and the resistance data recorded: TABLE 5 A Control # 1 Formula # 2 Ingredients Weigh »(gms.)% In Weight Weight (gms.)% In Weight Mineral Fibers 178.4 44.6 0 Expanded Perlite 120 30 150 39.8 Gypsum (calcined) 0 132.8 35.2 Paper Fibers (calcined) 0 28 7.4 Periodic Paper 64 16 36 9.6 Corn Starch 20 5 20 5.3 Clay 17.6 4.4 10 2.7 Mud Solids 4.0 7.0 TABLE 5 A (Continued) Formula # 3]? Ormula # 4 Ingredients Weigh) (gms.)% In Weight Weight (gms.)% In Weight Mineral Fibers 0 0 Perlite Expanded 150 39.5 150 39.8 Gypsum (calcined) 132.8 35.0 132.8 35.2 Paper Fibers (calcined) 28 7.4 28 7.4 Newspaper 29 7.6 21 5.6 Corn Starch 35 9.2 40 10.6 Clay 5 1.3 5 1.3 TABLE 5 A (Continued) Formula # 3 Formula # 4 Ingredients Weight (gms.)% In Weight Weight (gms.)% In Weight Mud Solids 7.1 7.0 TABLE 5 B Thickness Density Sample No. cm (pls.) G / cc (lbs ./pie3) Control the 1.527 0 601) .182 (11.39) Ib 1.504 0 592) .181 (22.31) le 1.488 0 .586) .180 (11.25) Id 1.488 0 586) .179 (11.19) le 1.466 0 577) .180 (11.25) Medium 1.494 0 588) .1805 (11.28) Formula 2a 1,308 0 .515) 169 (10.58) 2b 1,323 0 .521) 1688 (10.55) 2c 1,334 '0 .525) 1693 (101.58) 2d 1,374 0 .541) 1763 (11.02) Medium 1,336 0 .526) 171 ( 10.69) Formula 3a 1,321 r0 .520) 1758 (10.99) 3b 1,318 (0 .519) 1709 (10.68) 3c 1,334 '0 .525) 1698 (10.61) 3d 1,361 0,536) 1741 (10.88) 3e 1,407 (0 .555) 1766 (11.04) TABLE 5 B (Cont.) Thickness Density Sample No. cm (plq.) J / cc (lbs./] Die3) Average 1,348 (0.531) .1764 (10.84) Formula 4a 1.367 (538) .1757 (10.98) 4b 1.313 (0.517) .1728 (10.80) 4c 1.318 (0.519) .1707 (10.67) 4d 1.318 (0.519) .1730 (10.81) 4e 1389 (0.547) .1762 (11.01) Mean 1.341 (0.528) .1736 (10.85) TABLE 5 B (Continued) Load at 1a Rupture MOR Sample No. kg / (lbs.) Kg / cm2 (i) if) Control the 1.89 (4.17) 3.248 (46.2) Ib 2.22 (4.88) 3.916 (55.7) le 1.94 (4.27) 3.494 (49.7) Id 1.91 (4.2) 3.438 (48.9) le 2.04 (4.5) 3.803 (54.1) Medium 2.00 (4.4) 3.578 (50.9) Formula 2a 1.66 (3.65) 3.866 (55.0) 2b 1.48 (3.27) 3.388 (48.2) 2c 1.83 (4.02) 4.098 (58.3) 2d 1.66 (3.65) 3.508 (49.9) TABLE 5 B (Continued) Load at 1st Break MOR Sample No. kg / (lt> s.) Kg / cm2 (p Si) Medium 1.66 (3.65) 3.719 (52.9) Formula 3a 2.78 (6.12) 6.362 (90.5) 3b 2.21 (4.87) 5.083 (72.3) 3c 2.14 (4.72) 4.816 (68.5) 3d 2.12 (4.68) 4.584 (65.2) 3e 2.35 (5.18) 4.731 (67.3) Medium 2.32 (5.11 ) 5.118 (72.8) Formula 4a 3.51 (5.53) 5.37 i (76.4) 4b 1.89 (4.18) 4.400 (62.6) 4c 1.93 (4.25) 4.436 (63.1) 4d 1.84 (4.05) 4.225 (60.1) 4e 2.15 (4.73) 4.443 (63.2) Medium 2.07 ( 4.55) 4.577 (65.1) Ceiling tiles were also tested for wet strength when taking samples before drying in the oven. The experimental tiles with 17% and 15% of total paper fibers handled very well, similar to the control. The tile with 13% paper fiber was somewhat weaker. It was concluded that the ceiling tiles contain 15% to 17% paper fiber, 40% expanded perlite and 10% starch binder, which provide comparable processing and physical properties to the mineral fiber-based roof tile. Example 6 The following formulations were used to compare using periodic paper / co-calcined gypsum with a physical mixture of gypsum and newspaper without calcining. Table 6 A Control Compound (Fiber Hemihydrate Periodic Paper Mineral Ingredient) (calcined) and Gypsum Mineral Wool 44.6% 0 0 Expanded Perlite 30.0% 40% 40% Total Fibers 16.0% 16% 20-22% Paper (Newsprint) Plaster 0 34% 32% Corn Starch 5.0% 10% 7 - 9 Clay 4.4% 0 0 Flocculant 0.06Í 0. 06 0 Surfactant 0.08Í 0. 08 0 Mud Solids 4% 7% 7% When preparing the roof tile mats, the surfactant (when used) was added to the desired amount of water and mixed. Then, periodic paper (hydropulped) was added followed by mixing. The expanded perlite and wool mineral (when used) are added with continuous mixing. Finally, the clay when it is (used) and starch are added, with continuous mixing for approximately 3 minutes until a homogeneous sludge is formed, after which the flocculant (when used) is added and mixing continues for another 15 seconds . When preparing the non-mineral wool roof tiles, the clay and mineral fiber were replaced with gypsum and pefiodic paper. The mat was formed by emptying the sludge into a Tappi Box where it was mixed lightly, and subsequently there was gravity unloading and vacuum was applied to the wet mat to remove the excess water. Then, the mat was wet pressed to the desired thickness j / L in a static press, also removing additional excess water. The wet mat was tested for wet overlap resistance before drying. The mats were steam-dried at 316 ° C (600 ° F) for 30 minutes followed by drying at 177 ° C (350 ° F) for 90 minutes. It has been found that in the non-mineral wool formulation, the amount of paper fibers (newspaper) should be at least about 20% by weight for acceptable matting. The formulation using the co-calcined composite slightly increases the discharge time, especially at a higher content of paper fibers. There was no significant effect on discharge using the gypsum and newsprint mix even at a level as high as 22%.

The mat made with the hemihydrate composite was easy to handle during processing and had wet overlap resistance comparable to the control of mineral fibers, with both formulations containing 16% paper fibers. The composite material, which provides a mat in which the wet overlap had good deflection during the test. After the test, the wet overlap break line was lightly pressed by hand before drying, after which the wet overlap line was completely healed. The mat made with a mixture of gypsum and newsprint generally had a weaker wet overlap strength, however at 20% of the newsprint level, it had a wet overlap strength comparable to the hemihydrate compound formulation at 16% of fiber content of paper. The retention in weight in tiles made with the hemihydrate compound was generally superior to the tiles made with a mixture of gypsum and newspaper. This indicates that there could be loss of gypsum, as well as segregation of perlite, in the formation of mat using the mixture. As noted previously, both types of experimental tiles were harder to cut than the mineral fiber tile. The densities of both types of experimental tiles were slightly higher than the control, due to the lower thickness of the mat. The smaller thickness was the result of return elastic after pressing the mineral fiber mat, while the paper / plaster fiber mat does not spring elastically. The MOR resistance of both types of experimental tiles was acceptable or better than mineral fiber control tiles. Example 7 The following formulations were used to evaluate the effect on the cutting capacity of newspaper and gypsum (without calcining) hydropulped and the same newspaper and gypsum (calcined) as a complete replacement for mineral fibers: TABLE 7A Perlite Starch ramc 3 % in Gram Weight o. or in Weight 1 165 44 22.5 6 2 135 36 52.5 14 3 165 44 37.5 10 4 135 36 37.5 10 5 150 40 52.5 14 6 150 40 22.5 6 7 157. .5 42 33.8 9 8 142. .5 38 41.3 11 9 153. .8 41 30 8 10 146. .3 39 45 12 11 153. .8 41 41.3 11 12 146 .3 39 33.8 9 TABLE 7A (Continued) Perlite Starch Sample Gram% in Weight Gram% in Weight 13 150 40 37.5 10 TABLE 7A (Continued) Newspaper Yes »0 Sample Gram% in Weight Gram% in Weight 1 67.5 18 120 32 2 67.5 18 120 32 3 52.5 14 120 32 4 82.5 22 120 32 5 52.5 14 120 32 6 82.5 22 120 32 7 63.8 17 120 32 8 71.3 19 120 32 9 71.3 19 120 32 10 63.8 17 120 32 11 60 16 120 32 12 75 20 120 32 13 67.5 18 120 32 All these formulations were formed in sludges or aqueous sludges that have 7% by weight of solids content. In the case of newsprint / co-calcined gypsum, the ratio of gypsum to newsprint was:, and additional newsprint was added to provide the amount of newsprint established in the previous formulation. When evaluating ls 13 sample tiles, the following data were recorded: TABLE 7B Cutting Capacity Strength Cut Type Sample Calcined Without Calcining Calcined Without Calcining 1 23.8 19.8 Very Burdo Very Burdo 2 20.9 12.7 Clean Bordo 3 22.7 16.0 Very Burdo Very Burdo 4 21.6 21.1 Very Burdo 5 17.6 13.2 Burdo Burdo 6 28.1 21.8 Very Burdo Very Burdo 7 17.6 14.3 Slightly Slightly Burdo Burdo 8 17.4 20.0 Slightly Slightly Burdo Burdo 9 21.4 18.7 Clean Slightly Burdo 10 23.4 16.8 Slightly Clean Burdo 11 23.4 16.7 Slightly Clean Burdo 12 25.0 19.7 Burdo Burdo TABLE 7B (Cont.) Cutting Capacity Strength Cut Type Sample Calcined Uncalcined Calcined Uncalcined 13 27.8 16.0 Clean Burdo Cutting capacity is a measure of two factors - how difficult it is to cut with a manual blade and the appearance of the blade. cut. A two-piece accessory was designed to perform cutting tests. A supported piece holds a sample of a 7.62 x 10.16 cm (3 x 4 inch) ceiling tile in place and a standard blade is placed at an angle of 30 ° to the sample in the other piece. The cutting tests are performed on an Instron Universal Testing Machine, with the unit operating in a tension mode and the crosshead speed that is set to 50.8 cm (20 inches) / minute. This test approaches the action of cutting a tile with a manual blade. Results are reported as the force required to cut the sample and a description of the appearance of the cut. Compared to the difficult to cut plaster / newsprint formulations, all mineral fiber tiles had a clean cut and required an approximate average force of 11. As a result of the difficulty in cutting the tiles containing the gypsum / paper compound co-calcined newspaper or the physical mixture of gypsum and paper fibers (without calciner) it is preferred that the tile formulation contains at least about 10% dry weight of mineral fibers. Example 8 A plant test was performed using the following formulations, with the gypsum and hydropulpated newspaper that is physically mixed in the formulation without co-calcining: TABLE 8A Ingredients Formulation Formulation and Other Factors AB Expanded Perlite 39% 41% Periodic Paper ( hydropulped) 22% 20% Gypsum 32% 32% Starch 7% 7% Solids Content 5.5% 5.5% Line Speed 9.147 9, .144-10.36 meters (feet / min) (30) (30-34) Line speed of start-up (Formulation A) was 9. 144 m / min (30 ft / min) and this was increased to 10.36 meters / min (34 ft / min) during the last part of the second test (Formulation B). The wet mats were dried with the following dryer temperature ranges after starting.

TABLE 8B Dryer # 1 Dryer # 2 Dryer # 3 Dryer # 4 Formulation A 421-428 ° C 237-256 ° C 209-244 ° C 209-244 ° C (790-802 ° F) (458-492 ° F) (409-471 ° F) (408-471 ° F) Formulation B 420-438 ° C 243-260 ° C 215-234 ° C 215-232 ° C (788-821 ° F) (470-500 ° F) (418-454 ° F) (419-450 ° F) The mats did not exhibit warping after drying, and all dry panels passed through the cutters. Approximately 6,039 m2 (65,000 ft2) of panels were produced. The mud consistency in both tests was approximately 5.5% by weight which appears to be acceptable. Water does not separate from the material when it is poured on a smooth surface (sink test). Mud feed speed was maintained at approximately 1, 514 liters (400 gallons) / min during both tests. The wet mat was pressed to a thickness of approximately 1.55 cm (0.610 inch) before drying, which removed some of the excess water. The final density of the dry panels was approximately 0.208 g / cc (13 pounds per cubic foot).

Example 9 Another plant test was performed where 33% of mineral fibers were replaced with gypsum and additional newspaper and a second formulation where all the mineral fibers were replaced. The following formulations were used: TABLE 9A Ingredient Formulation A Formulation B Expanded Perlite 35% 39% Periodic Paper (hydropulped) 16% 22% Plaster 12% 32% Starch 10% 7% Mineral Fiber 27% 0% In both tests, the starting line speed was 9.14 m (30 ft) / min, however due to the use of additional dilution water, the line speed was reduced to 8.53 m (28 ft) / min (Formulation A) and 8.23 m (27 ft) / min (Formulation B). The following data was recorded: TABLE 9B Nos. Thickness Sample No. * Time Samples cmípul .gadas) l and 2 1:00 6 1,580 (0.622) 3 and 4 1:15 and 1:30 6 1,590 (0.626) 5 and 6 2:15 6 1.623 (0.639) 7, 8 and 9 2: 20 and 2:25 9 1.560 (0.614) 10 3:15 3 1.554 (0.612) TABLE 9B (Cont.) Thickness Noe Displays No 1. * Hourly Time cm (inches) 24 and 25 Start 6 1,542 (0.607) 11 4:: 35 3 1,582 (6.23) 12 4:: 55 3 1,615 (0.666) 13, 14 and 15 5:: 15 and 5:20 9 1.618 (0.637) 16, 17 and 18 6: 10 and 6:20 9 1.615 (0.636) 19 and 20 6: 30 6 1.570 (0.618) 21 and 22 6: 40 6 1.633 (0.643) TABLE 9B (Continued) MOR Density Sample Nc). * G / cc (Ib. / Ft3) kg / cm2 (Psi) 1 and 2 .176 (11.0) 9.56 (136) 3 and 4 .224 (14.0) 15.66 (223) and 6 .192 (12.0) 11.74 (167) 7, 8 and 9 .195 (12.2) 12.58 (179) ,182 (11.5) 11.18 (159) 24 and 25.219 (13.7) 13.92 (198) 11.237 (14.8) 18.21 (259) 12.229 (14.3) 17.36 (247) 13, 14 and 15 .214 (13.4) 15.68 (223) 16, 17 and 18,205 (12.8) 14.34 (204) 19 and 20 .210 (13.1) 15.33 (218) 21 and 22.219 (13.7) 16.38 (233) * Samples 1 to 10 were 33% replacement of mineral fibers and 11 to 25 were 100%. The buckling in both tests was minimal and all the panels passed through the grooves. There was minimal calcination of the gypsum in the dryers. During processing, the initial sludge consistency (33% replacement) was approximately 6.6% by weight solids. Due to the high consistency, the mud flow was not so uniform and the wet mat cracked before dehydration with vacuum. The mass diameter for the sinking test was only 16.5 cm (6.5 inches) indicating inadequate sludge flow. The addition of dilution water solved the sludge flow problem and reduced the sludge consistency to . 4% solids. The mass diameter for the sinking test was 24.13 cm (9.5 inches) (normal). After the test, an additional dilution of water reduced the consistency to 4.9% solids without adverse effect on the mat formation. In the 100% mineral fiber replacement test, the initial sludge consistency was 6.3% solids. This caused some cracking in the mat formation which was resolved by adding dilution water, reducing the consistency to 5.4% solids and providing a mass diameter for sag test of 24.13 cm (9.5 inches).

Claims (42)

1. CLAIMS Having described the invention, it is considered as a novelty, and therefore the content of the following clauses is claimed as property: 1. Improvements in a free composition of wetted mineral wool, suitable for producing anti-noise tiles that essentially consist of plaster, cellulosic fibers, expanded perlite and a binder, wherein on a base of dry solids, there is at least about 20% by weight of gypsum and at least about 15% by weight of cellulosic fibers.
2. 2. Composition improvements according to clause 1, characterized in that the binder is starch and is present in a dry solids base in an amount in the range of about 5 to about 15% by weight.
3. 3. Composition improvements according to clause 1, characterized in that the expanded perlite is present in a dry solids base in an amount of at least about 25% by weight.
4. 4. Composition improvements according to clause 1, characterized in that the cellulose fibers comprise paper fibers and are present in a dry solids base in an amount in the range of about 15 to about 25% by weight.
5. 5. Composition improvements according to clause 2, characterized in that the plaster is in the range of approximately 20 to about 40% by weight, the expanded perlite is in the range from about 20% to about 50% by weight and the cellulose fibers comprise paper fibers that are in the range from about 15% to about 25% by weight.
6. 6. Improvements in a free composition of wetted mineral wool, suitable for producing sound-insulating tiles that essentially consist of gypsum, cellulose fibers, expanded perlite and a binder, wherein at least a portion of the gypsum and the cellulosic fibers are in the composition. form of a composite material that has been produced by calcining under pressure a sludge diluted with gypsum and cellulose fibers.
7. 7. Composition improvements according to clause 6, characterized in that the composite material is calcium sulfate alpha hemihydrate that has been co-calcined with cellulosic fibers.
8. 8. Improvements in the composition according to clause 6, characterized in that the cellulosic fibers are paper fibers.
9. 9. Composition improvements according to clause 6, characterized in that on a dry solids basis there is at least about 20% by weight of gypsum and at least about 15% by weight of cellulose fibers.
10. 10. Composition improvements according to clause 7, characterized in that the cellulose fibers are paper fibers.
11. 11. Composition improvements according to clause 9, ca characterized in that a portion of the cellulose fibers is added to the composition as uncalcined fibers in addition to the gypsum composite material / calcined cellulose fibers.
12. 12. Composition improvements according to clause 9, characterized in that the gypsum is in the range from about 20% to about 40% by weight and the cellulose fibers are in the range from about 15% to about 25% by weight. weight.
13. 13. Improvements in the composition according to clause 12, characterized in that the cellulosic fibers comprise paper and a portion of the paper fibers is added to the composition -as fibers without calcining, in addition to the material composed of paper fibers / calcined gypsum.
14. 14. Improvements in a mineral wool free composition, wetted, suitable for producing sound-insulating tiles, which essentially consists of gypsum, cellulose fibers, expanded perlite and a binder, where on a dry solids basis there is at least about 15% by weight of cellulose fibers, and a substantial portion of the gypsum and a minor portion of the cellulose fibers are in the form of agglomerated board and ground.
15. 15. Composition improvements according to clause 14, characterized in that there is at least about 20% by weight of gypsum.
16. 16. Composition improvements according to clause 15, characterized in that the gypsum is in the range from about 20 to about 20% by weight and substantially all of the gypsum is in the form of agglomerated board of solid gypsum plaster.
17. 17. Composition improvements according to clause 16, characterized in that the cellulose fibers comprise paper and the main portion of the paper fibers is periodic paper added to the composition to supplement the paper fibers in the agglomerated board of ground gypsum.
18. 18. Improvements in a wetted composition suitable for producing sound-insulating tiles consisting essentially of mineral wool, gypsum, cellulose fibers, expanded perlite and a binder, wherein on a dry solids basis there is at least about 10% by weight of mineral wool , at least about 10% by weight of gypsum and at least about 15% by weight of cellulose fibers.
19. 19. Improvements in the composition according to clause 18, characterized in that the binder is starch and is present in an amount in the range of about 5% to about 15% by weight.
20. 20. Improvements in composition according to clause 18, characterized in that the expanded perlite is present in an amount of at least about 25% by weight.
21. 21. Liejoras in the composition according to clause 18, characterized in that the cellulose fibers comprise fibers of paper and are present in an amount that is in the range from about 15% to about 25% by weight.
22. 22. Composition improvements according to clause 18, characterized in that the amount of mineral wool is in the range of about 10% to about 30% by weight.
23. 23. Composition improvements according to clause 19, characterized in that the gypsum is in the range from about 10% to about 25% by weight, the expanded perlite -is in the range from about 25% to about 40% in weight, and the cellulose fibers consist of paper fibers that are in the range of about 15% to about -25% by weight.
24. 24. Composition improvements according to clause 19, characterized in that at least a portion of the gypsum and the cellulosic fibers are in the form of a composite material that has been produced by calcining under pressure a sludge of yeas and cellulose fibers.
25. 25. Composition improvements according to clause 19, characterized in that a substantial portion of gypsum and a minor portion of the cellulosic fibers are in the form of the agglomerated board of ground gypsum.
26. 26. Improvements in a wool-free sound-insulating tile p? dry bulk, consisting essentially of gypsum, cellulose fibers, expanded perlite and a binder, wherein at least about 20% by weight of gypsum and at least about 15% by weight of cellulose fibers.
27. 27. Improvements in the soundproofing tile according to clause 18, characterized in that the binder is at the midon and an amount that is in the range from about 5% to about 15% by weight is present.
28. 28. Improvements in the soundproofing tile according to clause 18, characterized in that the expanded perlite is present in an amount of at least about 25% by weight.
29. 29. Improvements in the soundproofing tile according to clause 18, characterized in that the cellulose fibers comprise paper fibers and are present in an amount in the range of about 15% to about 25% by weight.
30. 30. Improvements in the soundproofing tile according to clause 19, characterized in that the gypsum is in the range of about 20% to about 40% by weight, the expanded perlite is in the range of about 25% to about 50%. % by weight and the cellulose fibers consist of paper fibers in the range of about 15% to about 25% by weight.
31. 31. Improvements in a wool-free sound-insulating tile p? dry bulk, which essentially consists of gypsum, cellulose fibers, expanded perlite and a binder wherein at least a portion of the gypsum and the cellulosic fibers are in the form of composite material that has been produced by calcining under pressure Diluted mud from gypsum and cellulose fibers.
32. 32. Improvements in the soundproofing tile according to clause 31, characterized in that there is at least about 20% by weight of gypsum and at least about 15% by weight of cellulose fibers.
33. 33. Improvements in the soundproofing tile in accordance with clause 32, characterized in that the cellulosic fibers are paper fibers.
34. 34. Improvements in the soundproofing tile according to clause 32, characterized in that a portion of the cellulose fibers are uncalcined paper fibers in addition to the material composed of calcined cellulose fibers / gypsum.
35. 35. Improvements in the soundproofing tile according to clause 32, characterized in that the gypsum is in the range of approximately 20% to approximately 40% by weight and the cellulose fibers are in the range of approximately 15% to approximately 25% in weigh.
36. 36. Improvements in an anti-noise tile that essentially consists of mineral wool, gypsum, cellulose fibers, expanded perlite and a binder in which there is at least about 10% by weight of mineral wool, at least about 10% by weight of gypsum and at least about 15% by weight of cellulose fibers.
37. 37. Improvements in the soundproofing tile in accordance with clause 36, characterized in that the binder is a_l middn and is present in an amount in the range of about 5 to about 15% by weight.
38. 38. Improvements in the soundproofing tile according to clause 36, characterized in that the expanded perlite is present in an amount of at least about 25% by weight.
39. 39. Improvements in the soundproofing tile according to clause 36, characterized in that the cellulosum fibers are paper fibers and are present in an amount in the range of about 15% to about 25% by weight.
40. 40. Improvements in the soundproofing tile according to clause 36, characterized in that the amount of mineral wool is in the range of approximately 10% to approximately 30% by weight.
41. 41. Improvements in the soundproofing tile according to clause 37, characterized in that the gypsum is in the range of approximately 10% to approximately 25% by weight, the expanded perlite is in the range of approximately 25% to approximately 40% by weight and the cellulose fibers are paper fibers that are in the range of about 15% to about 25% by weight.
42. 42. Improvements in the soundproofing tile according to clause 37, characterized in that at least a portion of the gypsum and the cellulose fibers are in the form of a composite material which has been produced by calcining under pressure a Diluted mud from gypsum and cellulose fibers. In compliance with the provisions of Article 47 of the Inventions and Trademarks Law in force, I declare under protest that the invention described above is the best known method for putting this invention into practice. In testimony of which, I sign the present in Cuerna vaca, Morelos on January 31, 1995. USG INTERIORS, INC.