MXPA00001184A - Method of manufacture for textured surface panels and panel products made therefrom - Google Patents

Abstract

An improved method for texturing gypsum fiber panels and producing surface textured panels, edge tapers, and deeper patterned wainscot-type panels, involving the use of a flexible die (20) with a texturedsurface. The die (20) is pressed onto the panel in its slurry state just after the onset of an exothermic rehydration reaction. Partial hydration and setting occur during pressing by the die (20) to form a textured mat (M). The mat (M) is removed from contact with the die at a point along the rehydration temperature curve about at or less than one-half of the rise to the greatest rehydration temperature.

Description

METHOD FOR MAKING PANELS OF TEXTURED SURFACE AND PANEL PRODUCTS MADE WITH THEMSELVES BACKGROUND OF THE INVENTION The present invention relates in general to the ability to impart surface textures on composite materials for use in the construction industry. More particularly, the present invention relates to the use of flexible light weight matrices for imparting surface texture to composite materials, when the composite materials are still in a semi-fluffy state. The gypsum fiber board process of the United States Gypsum Company, as illustrated and described in US Pat. No. 5,320,677, and herein incorporated by reference in its entirety, describes a composite product and a process for producing a composite material, wherein a diluted sludge of gypsum particle and cellulosic fibers is heated under pressure to convert the gypsum, i.e. calcium sulfate , in the stable dihydrate state (CaS04.2H20), in calcium sulfate alpha hemidrate having acicular crystals. The cellulosic fibers have pores or voids in the surface and alpha hemihydrate crystals are formed in the interior, over and around the voids and pores in the cellulosic fibers. The heated sludge is then dewatered to form a mat, preferably using equipment similar to papermaking equipment, and the sludge is cooled sufficiently to begin rehydration of the hemihydrate to gypsum, whereby the mat is pressed on a chipboard. the desired configuration. The pressed mat is subjected to an exothermic reaction and rehydrated in gypsum to form a dimensionally stable, strong and useful board for construction. The board is then trimmed and dried. One of the many advantages of the process described in the '677 patent is that a surface texture can be imparted to the resulting gypsum panel, as the panel is formed. Two such board examples are textured panels for room fabrication applications, and surface relief panels for a variety of markets. The challenge in the surface texturing of gypsum fiber boards during in-line processing is the synchronization of the impression made in the mud or the wet mat. As the rehydration begins and the mass solidifies, an exothermic reaction is carried out. First, after calcination, there is cooling of the mat as the sludge dehydrates, such as by vacuum extraction, and a primary press disposed on the moving conveyor belt or screen. The primary dewatering press is employed as a first press to remove up to about 90% of the free water remaining after vacuum extraction. Before rehydration, it is important to remove usually about 80-90% of free water while reducing the temperature of the filter cake. Dehydration processes contribute significantly to reduce the temperature of the filter cake. Extracting free water is necessary when looking for texturing and wet pressing the filter cake to a desired product structure. Alternatively, the filter cake can be dried immediately and then cooled to a stable hemihydrate but rehydratable for later use. Therefore, it is also convenient to remove as much as possible of the free water that is not required in the compound mass for rehydration, before the temperature drops to the rehydration temperature. When the rehydration temperature is reached, which may require additional cooling, an exothermic reaction is carried out. The exothermic reaction results in a hydration curve that is plotted as temperature with time or distance on the conveyor. As the calcium sulfate hemihydrate, rehydratable and the cellulose fibers in a sludge form leave the headbox, the hemihydrate crystals will have a temperature generally in the range of about 82.2-98.9 ° C (180 to 210 ° F approximately). Later, the sludge is dispersed through the conveyor and the action of the vacuum pumps starts to withdraw the free water and the temperature drops significantly. The rehydration temperature in the carrier may vary depending on the additives and accelerators employed, but in general it is in the range of about 15.6 ° C (60 ° F) to about 48.9 ° C (120 ° F). This would trace the starting point or under the hydration curve or so-called temperature trace. At this point, the exothermic reaction arises and heat is released. The temperature trace will show an increased curve until a substantially constant dependent trace is reached (linear) of increased temperature with time, or distance. The exothermic reaction will then thin out resulting in a graphical change from an ascending linear slope to a curved trace reaching a peak temperature, signaling a decrease in the hydration rate. Subsequently, the curve tilts down as the reaction drops to reach 100% hydration. Finally, the board can be dried to remove any excess water. The critical key to imparting texture is to find where in the temperature curve between the start of hydration and its termination the texturing should occur so that a) the texturing does not end too soon for the fraging compound to maintain or retain the relief b) the structures from plaster to circular glass in formation are not destroyed and c) the impression is not imparted so late that the surface texture is broken by being fixed very firmly to receive the texture. The usual selection method for imparting textures in wide panels is using a roller to texture a mouldable surface, such as is done with roof tile with wet felt. However, the manufacture of these rolls typically has long deadlines and high costs. Another option is to make flat sheets and then stick them to the roller. Unfortunately, for both methods, the manufactured rolls then have very little opportunity to change the textured pattern. Rolling processes to date have not proven to be highly successful. A third roller method is the manufacture of rubber sleeves on nickel or para-aramid brand KEVLAR, which can then be slipped into or out of a mandrel, generally using compressed air. This method allows texture changes using less expensive sleeves on a common mandrel, however it still has long lead times for initial fabrication. A rollless option, commonly used for raised hardboard and some cement board products, involves machining a steel plate, placing it against a surface and applying sufficient pressure and / or heat on a platen press to impart the texture to a panel surface. These surfaces imparted in general are of very high quality. Steel platens have the added advantage of making it easy to change textured patterns, always having a different platen pattern in stock. However, this method requires difficult and heavy equipment that is associated with the handling of steel plates, especially with larger panels. In addition, these large steel plate matrices tend to be expensive. Deep patterns, such as wood grain panels or wood siding panels can be made in at least one of four ways. Molded pieces of wood can be cut and added to panel products. The disadvantage for this method is the cost and time associated with the finishing of the corners and molded edges as well as maintaining uniformity of the panels. Uniformity can be increased by using a roller to impart the texture to a mouldable surface, such as is done with the roof tile with wet felt. However, the manufacture of these rolls typically has long terms and high costs. Deeper features, such as the molding of wood siding panels, require more machining with higher cost and even longer lead times. These rollers have very little opportunity to change the pattern of embossing. A third option involves machining a steel plate, placing it against a surface and applying sufficient pressure and heat to impart the texture to a panel surface as described above. A fourth method is to machine the profile or relief on the surface of the panel, which gives a rougher surface and generates substantially dust that must be collected, handled and disposed of, or recycled. SUMMARY OF THE INVENTION The present invention relates generally to producing panels of gypsum fiberboard with surface texture. More particularly, the present invention relates to the use of flexible light weight dies for imparting surface texture to gypsum board panels while the panels are in a semi-mud state. This invention involves a method for imparting texture to a gypsum fiber board, shortly after the start of rehydration and combination of the hydration curve with processing points on the production line. The invention allows to dehydrate the sludge by suction with vacuum, leaving the head box and then passing the sludge to a first press, just after the rehydration temperature has been reached, where additional dehydration occurs by removing approximately 80-90% of the remaining free water. At this point, a small percentage of rehydration of the hemihydrate has started and a wet fiber mat comes out of the primary or first press. In this union, the temperature of the sludge has decreased and will increase as rehydration occurs. A texturing matrix, as will be defined here, is then provided to be adapted to run in a second press. The location on the processing line to begin texturing is proportional to the increase in temperature velocity from the low point in the hydration curve, such that the textured matrix meets the mat substantially at a point where the mat is foldable and is partially rehydrated. The textured matrix is then placed in pressure contact against the mat, as the hydration is accelerated. Previously in the process of forming the sludge, acicular crystalline structures in the cellulosic fibers and gypsum have intermixed and formed a matrix. This matrix is pre-compressed in the first press and recompressed by the texturization matrix. The formation of fibers and crystalline expands upwards against the matrix due to hydration, leaving enhancements and other surface reliefs as desired by the manufacturer. The hydration gypsum with the fiber is expanded in the secondary press to a certain predetermined press clamp point thickness. The rupture of the rehydration and deformation crystals is minimized. It has been found that the starting point and duration of the texturing in relation to the hydration curve, is best achieved by starting slightly beyond the point of low temperature at the beginning of rehydration and continuing at a temperature level equal to approximately 25-60% of the final temperature increase, such that before leaving the texturization matrix, the hydration mat experiences up to about 25-60% of the maximum temperature level that occurs in the zenith of the curve. The method described to produce both large textured surface panels, smaller and deeper patterned wood cladding panels, splash-covered relief, edge tapering, and other types of textures, involve the use of a urethane matrix flexible with a textured surface. The urethane matrix is initially made from a master surface that has the desired texture. Once the urethane is applied to the master surface, it is allowed to cure and then remove. The resulting composite is a flexible urethane matrix having the master surface molded therein. This flexible urethane matrix is then applied to the composite material while the composite material is still in a semi-mud state. Sufficient pressure is applied to the urethane matrix to impart its texture to the composite material, while the composite material hardens. After a sufficient amount of time has passed, the urethane matrix is removed from the composite, and the resulting product is a textured surface board that is cut into panel sizes. BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a perspective view of an operator that empties a urethane compound on a master panel retained within a dam with a surface relief to which the urethane is formed when curing; Figure 2 is a cross-sectional view of the urethane covering the master panel of Figure 1, showing in criss-cross lines the filling of the master panel relief by the urethane; Figure 3 shows the detachment of the cured urethane layer imparted by the texturing of the master panel; Figure 3A shows in cross-section an edge taper shaped array removed from the mat leaving the panel edge taper relief for the resulting panels; Figure 4 shows a worker in a perspective view detaching the flexible urethane textured matrix from the master panel having wood facing form portions and wood grain surface textured portions, thereby providing both portions of surface textured as deep textured; Figure 4A is a plan view of a panel having a type of texturing known as splash-covered that is produced by the invention; Figure 4B is a cross section of the panel of Figure 4A showing the texturing characteristics; Figure 5 is a schematic view illustrating a production line for forming plasterboard agglomerate board having a head box, dewatering vacuum, primary dewatering press, feed structure and outlet for a textured matrix in combination with a secondary press, arranged to process a sludge of rehydratable gypsum fibers on a conveyor; and Figure 6 is a trace curve of hydration temperature over time, having a generic profile or model that reflects the processing steps on the production line of Figure 5, from when the calcined sludge begins rehydration in the transporter through rehydration; and Figure 6A is a graphical model of the range of approximate percentages of rehydration (setting) that is reached in stages on the production line of Figure 5. DETAILED DESCRIPTION OF THE PREFERRED MODALITY The present invention is directed to a training system for imparting texture to large agglomerate board panels of large surface gypsum fibers, to form textured panels and panels with relief on the surface, and in particular to the use of lightweight flexible matrices to impart texture on surface panels, when the panels are They find themselves in a semi-mud state. The training system generally designated with the number 10 and best illustrated in Figure 5, includes a head box 12, vacuum boxes 14, a wet press (primary) 16 for 1) clamping the filter cake mat to a desired thickness and 2) removing approximately 80-90% of the remaining water, and a secondary press 18 for 1) imparting a surface texture that is the negative image of the web surface or texturization matrix employed, 2) achieving a final calibrated panel thickness as the setting compound expands against the press matrix or band and 3) aids in improving the flexural strength as the crystalline compound expands during rehydration against the press matrix or band. The head box 12 is used to uniformly disperse the calcined sludge, which has at least about 70% by weight of liquid across the width of the conveyor or formation mixes, where vacuum boxes 14 are used to dehydrate the sludge in a mat with a general moisture content of 28-41% (wet basis) (40-70% moisture content on dry basis). The wet (primary) press 16 consisting of alternating suction clamping points and flat rollers, and a porous band further dehydrates and consolidates the mat under the combined effect of vacuum and pressure at a moisture content (wet basis) of 23- 35% (30-55% on dry basis). The similarities to conventional training lines known in the industry of wood fiber board production, allows its easy conversion. The spacing between the first and secondary presses - whether measured by time or distance, is linked to the hydration curve. Only slight hydration (approximately 5-10%) occurs in the primary press 16. The secondary press 18 is used for products of medium to higher density and imparts a surface texture (or smoothness) depending on the surface of the band or matrix used. This press 18 also decreases the variation in thickness by adjusting to a fixed space fixing point slightly less than the desired final resulting board thickness. The expansion of plaster against this fixed space surface also improves the resistance to final bending. The flexible lightweight matrix 20 of the present invention is to be used in conjunction with the secondary press 18 of the forming system 10 to impart selective surface textures of large panels made from composite material. Expansion of the crystal formation with the subject fibrous particles forces the setting mat against the texturing matrix 20, as the rehydration rate increases to reach a temperature level, with a certain percentage of the difference (? T) between the rehydration temperature and the highest temperature in the rehydration curve, at which point the mat leaves the press 18. Flexible Matrix Manufacturing for Textured Panels The method of the invention of using lightweight flexible matrices is particularly useful with a continuous process of set material, such as agglomerated fibreboard with gypsum. The preferred material is a urethane matrix that can be hand-fed easily through a continuous press that has sufficient pressure to compress or deform fine textures on the mat just after the point where setting begins. The mat is then removed after a certain amount of temperature rise has occurred and set. There is an elastic return of the composite mat on the conveyor, which is controllable to give more precision and control of the texture formation. The manufacture of urethane dies is generally known in the industry with respect to texturing and embossing of media susceptible to printing. In the present invention, there is the ability to induce both a light surface texture as well as a deeper pattern, such as can be used to create wood veneer panels or with deep wood grain. With reference to Figure 1, the worker emptying a liquid urethane compound 30 in a master panel 32 surrounded by a dam 34 to retain the drained urethane 30 will be illustrated. It will be seen that the master panel 32 has deep wood facing portions. W and lots of textured wood grain T around and in the wood siding portion. The master panel 32 can be made in this manner or it can be made with only textured T, wooden coating W, or both, as will be understood by those skilled in the art. In another embodiment, a shallow popular splashback texture can be obtained, which emulates the well-known manual technique of textured iron-tipped finishing by using a wide spatula to leave smooth flat parts surrounded by textured valleys, as will be discussed with respect to textures in Figures 4A and 4B. Still in another modality, boards with edge tapers can be made, such as E in Figure 3A, where the texturing has no grains or fluted, but simply marginal portions that have less depth than the rest of the board. The mat shown in Figure 3A will eventually be cut on the center line to make two boards B1 and B2. Other well-known textures can also be achieved, for example a brush chopping effect, stucco-like appearance and the like. As used in this specification and claims, the term "texture" broadly defines all types of surface or shallow relief that can be imparted to the setting mat, including but not limited to, a simple localized change in thickness, such as a taper. of edges, to more complex regular patterns, ie wood siding, a checkerboard-like appearance, grid-like configuration, repeated curves, arcs and the like, and also includes irregular random patterns such as grain relief to wood, texturing covered with splashes (tirol), chopped effects of brushes, stucco-like surfaces and the like. With reference to the cross-sectional view of Figure 2, it will be seen that the master panel 32 has a base of gypsum or other rigid material 36 and a hardened textured compound 38 superimposed to form the wood siding relief pattern W and the textured T. Textured composite 38 is first coated on gypsum board 36. It can be manually printed with tools such as brushes or other pattern forming implements, or it can be engraved by placing a wooden form against it that has the inverse form of wood veneer W, or other select pattern, before the texturizing compound 38 sets. In the embodiment described, the texturizing compound 38 comprises the texturized TUF-TEX composite made by the United States Gypsum Company. When the urethane compound 30 has been emptied into dam 34, it is allowed a curing time, typically about 12 hours at temperature in the range of about 76.7-85 ° C (170-185sF) as is known to those with skill in the specialty. Of course, urethane will cure if left simply at room temperature, but it will take much longer. Pre-applying a release compound on the textured 38 allows the set urethane 30 to peel off and lift upward, as illustrated in Figures 3 and 4, and roll up to form the full textured matrix 20. In Figure 4 , a worker is shown detaching the set urethane 30, which can then be rolled up for use in the process of the invention, schematically illustrated in Figure 5 (not drawn to scale). In the described embodiment, the length of the resulting array 30 is variable. It can also be made as a continuous band for continuous use in the secondary press 18 by joining its ends, such as by vulcanizing or other joining process. The length of the die 20 is determined by the length of the boards intended to be cut from the set mat. To use as a discontinuous matrix, a single matrix should be sufficient for a section of board, or if longer board sections are intended, multiple segments of matrices can be joined to make them sufficiently long in order to have a portion extending from a strue of feeding roller 40 through secondary press 18 to an output roller strue 42. The width depends on the width of the conveyor and the size of the board to be processed.

In the preferred form, a continuous texturization matrix extends through the conveyor 44 shown in FIG.

Figure 5. Typically, a fibreboard and gypsum board process will produce panels of 2.45 m (8 feet wide) by 4.88 m (16 feet) long, in a continuous process. For ease of handling, for a width of 2.45 m (8 feet) and length of 4.88 m (16 feet), the textured array will have a length of at least approximately i 4.88 m (16 feet) from the feed structure 40 to through the outlet structure 42. It is envisaged that the process 10 forms a setting mat 46 having an approximate normal depth of .635 to 1,905 cm (1/4 to 3/4 inch) to meet normal construction requirements. . Accordingly, it is envisaged that the textured T in Figures 2-4, S in Figures 4A and 4B and E in Figure 3A, will have a depth in the range of approximately .0635 - .127 cm (0.025 to 0.050 inch) to achieve an aesthetically pleasing finish. The texture S is typically shallower than a wood grain texture T. The depth of the wood veneer depends on the final flexural strength of the board to be produced and also depends on the accelerators and additives used in a particular system. The wood veneer W can typically be formed up to half the thickness of the resulting mat 46. Use of Flexible Matrix in Board Panel Manufacturing Fiber and Gypsum Agglomerate The method of using lightweight flexible matrices is particularly useful with a continuous process of setting material, such as the fiberboard process 10 is shown in Figure 5, and described in US Pat. No. 5,320,677. The urethane matrices 20 can be easily fed by hand through a continuous press 18 having sufficient pressure to compress or deform fine textures on the mat just after the setting begins and then remove after a suitable set amount has occurred. , but before reaching the maximum exothermic reaction temperature on the hydration curve. The pressure against the main upper band 49 of the secondary press 18 should be sufficient to displace the urethane matrix 20 and the rollers 48 of the secondary press 18. Rolls of the matrix 20 can be unrolled by hand, with the textured side against the upper part of the mat M as it enters the secondary press 18. As illustrated schematically in Figure 5, the urethane matrix 20 contains the mat M in the feed of the secondary press 18, where the mat is still unset and It is foldable. The hydration has just begun before the mat enters the secondary press 18. The mat M with a printed surface or surface relief, then begins to set while under the pressure of the urethane matrix 20. The matrix 20 it is separated from the formed panel 46 emerging from the secondary press 18, where the panel 46 has set to a somewhat stiffer condition, however below the maximum setting. The setting is to the point where the pressure moderate by the index finger of the person did not leave an indentation. The die 20 can then easily be wound onto the outlet structure 42 and fed back into the inlet of the secondary press 18 in the feed structure 40. Alternatively, the ends of the die 20 can be joined, such as by vulcanization to form an endless band which is placed around the secondary press 18 and rotates around to press continuously against the mat M. A plurality of dies 20 can also be joined for larger board lengths. By making a type of surface relief of panel board W, an increased pressure at the edge results in a densified and reinforced edge, damaging it less in handling and also during installation, as well as offering excellent fastener holding properties. Similarly, when a matrix 20 configured to create edge taper E is provided in Figure 3A, the board edges N are densified and produce improved clamping strength. The edge tapers E are typically provided to allow the joint and taper compound in the panel joints. The set compound 46 will then be separated on the center line and the edges trimmed, so that both boards B1 and B2 are provided with edge tapers E. In Figures 4A and 4B, a matrix 20 is formed to have the Negative image of the texturized style covered in splashes or tirol S. This shallow textured appearance has flattened peaks or flat portions 51 over surrounding textured valleys 52, creating a desired aesthetically pleasing appearance for interior construction. Figure 6 is a plot of hydration trace mcdelo for agglomerate board fiber-plaster setting. The shape of the curve will also be understood by those in the industry, as representative of the curca of temperature to which the rehydrated calcinated gypsum is subjected, when it is mixed with water and the temperature drop at the rehydration level after leaving a pot of calcination. Certain points on this hydration curve are critical to the invention with respect to how the hydration curve joins or combines with corresponding processing steps or points in the production line process, ie from (a) to the output of the head box 12 on the conveyor 44, b) dehydrated by vacuum boxes 14, c) passage through a first press 16, d) move through a distance on the conveyor 44 and then e) pass through the secondary press 18 for a certain duration, whereby the mat 46 leaves the secondary press 18 at a desired point on the hydration curve of Figure 6. Figure 6A is a plot of the setting ranges estimated at certain points corresponding to to the points labeled in Figure 6 and showing the percentage range of maximum hydration (set) at each point. The Y axis is the percentage of hydration that is reached and the X axis is the position of the mat as it passes through process 10. In Figure 6, it will be seen that the Y axis is the temperature and the X axis is the time . The temperature curve reflects a starting point A at time zero or approximately at the point after the sludge is fed on the conveyor 44 from the headbox and has been dehydrated by the vacuum boxes 14 to lower the rehydration temperature , which is typically approximately 15.5 ° C (60 ° F) to approximately 48.9 ° C (120 ° F). The temperature that has fallen from the upper calcination temperature in the calcination kettle (not shown) when fed to the head box 12, which may be approximately 93.3 ° C (200 ° F) or more when it is first emptied onto the conveyor 44. Point A is the rehydration temperature. The point A 'is the point shortly after when the mat M enters the primary press 16, where hydration has begun. The primary press (wet) 16 removes approximately 80-90% of any remaining free water by the use of suction rollers and simple alternating ones. The mat M leaves the press 16 at point A "where the exothermic hydration reaction has reached approximately 5-10% of the maximum temperature increase It has been learned that the starting point B for successfully creating surface impressions is after that a slight amount of hydration and set has occurred, and continuing only for part of the subsequent hydration period.This period of time has been found to be enough time for the temperature to reach a value B 'shown as a range in the Figure 6. Point C is the highest temperature reached by the exothermic reaction: Mat M enters secondary press 16 at point B, where the temperature has reached approximately 15-25% of the increase from A to C (? T The mat M leaves the secondary press 18 at point B 'where the temperature has risen to approximately 25-60% of the increase from A to C (? T) In the secondary press 18, the agglomerated board of fibers and plaster, forges and expands. The secondary press 18 and the transported matrix 20 fasten the mat M. The expansion pressure of the rehydrating plaster causes the mat to fill the matrix texture W, T, E or S. When the contact between the matrix 20 and the mat 46 at point B ', there will be enough set to retain the textured detail. Therefore, keys for the present invention require a) that the mat M come into contact with the matrix 20 while it is soft or soft, b) the expansion of the setting mat under the matrix press for a period of time so that enough range set and c) then leave the matrix at point B 'which falls in the range shown in Figure 6 on the temperature curve with the relief that is maintained from there. The temperature control of the exothermic process can be slowed down or accelerated by the use of additives, retarders and other catalysts as known in the prior art methods to rehydrate calcium sulfate hemihydrate. Of course it is necessary to lower the temperature of the sludge with minimal remaining free water, so that rehydration does not occur in the presence of excess water. With respect to the temperature curve of Figure 6, the X axis can alternatively be distance on the conveyor 44 instead of time. The shape of the curve over the distance would generally be the same configuration where there is a drop in temperature that leaves the head box to a point where rehydration begins at point A, with the curve that then rises to a point B and then point BJ which is a point on a portion of the curve that has a constant slope generally linear up to a point B. It is on this line of constant slope that the exothermic reaction accelerates rapidly and where the texturing pressure of the matrix 20 occurs for up to about 25-60% of the rise to the maximum temperature point C. After the point B "is reached, the reaction is braked and the linear trace changes to a forward curve before reaching the exotherm temperature maximum C. It is expected that with a start level of hydration A of approximately 15.5-48.9 ° C (60-120 ° F), the highest temperature C would be from approximately 21.1-60 ° C (70-140 ° F). This temperature is greatly influenced among other things, ambient conditions in a panel plant without the presence of thermal collectors of metal structure on the conveyor line. Then after point C, the temperature trace is curved downward as the compound approaches complete rehydration at point D. Points A, JB, BJB ", C and D have been placed in Figure 5 denoting the corresponding locations in this schematic illustration of process 10. Figure 5 is not drawn to scale Figure 6A plots the percentage of complete setting ( rehydration) on the Y axis at the corresponding locations on the X axis for points A, AJB, B ', B ", C and D of Figures 5 and 6. At point AJ the mat M enters the primary press 16 no more than about 5% rehydration. It comes out at approximately 5-10% rehydration. Upon entering the secondary press 18, mat M has been found to have reached approximately a setting of 20-30%. By leaving the secondary press 18 at point B J a person can not leave a fingerprint using moderate pressure and it is estimated that the hydration is approximately 40-70% complete. At the highest temperature C generated from the heat evolved by the exothermic reaction, hydration has been empirically found to be approximately 80-90% complete. The board is then usually cut into panel widths and lengths and reaches a final setting at point D. Drying in an oven at ambient conditions then follows. The increase in temperature during hydration and the time or distance over which the increase is carried out depend on various calcination factors, such as among others, the proportions of gypsum and fiber, the amount of water present and of course the amounts of retarding accelerator additives and catalysts that can be changed to increase or decrease the setting time. Various features of the invention have been particularly shown and described in connection with the illustrated embodiments thereof. However, it should be understood that these particular products, and their method of manufacture, do not limit but merely illustrate and that the invention should be given its fullest interpretation within the terms of the appended claims.

Claims (29)

1. CLAIMS 1. A method for producing agglomerated board of fibers and textured gypsum, characterized in that it comprises the steps of: mixing ground gypsum and host particles of a fibrous reinforcement material and sufficient liquid to make a diluted sludge consisting of at least about 70% of liquid in weight; calcining the gypsum, in the presence of the host particles by heating the sludge diluted under pressure, to form crystals of acicular calcium sulfate alpha hemihydrate; separating a portion of the liquid from the calcined gypsum and host particles to form a filter cake; reduce the temperature of the filter cake to the rehydration temperature of the calcined gypsum to begin setting; First press the filter cake to form a board to remove additional water from there; provide a flexible matrix having texture on one side and second pressing the texture of the flexible matrix against the board while the board is forging and folding; allow the board to continue to set while under pressure from the flexible matrix; separate the board from the flexible matrix before full setting; and dry the board to remove any remaining free water. The method according to claim 1, characterized in that the step of providing a flexible matrix further includes preparing a flexible urethane matrix from a master panel having texture. 3. A method for producing a textured fiber and gypsum composite material, comprising the steps of: producing a urethane matrix from a master surface; cure the urethane matrix; removing the urethane matrix from the master surface; applying the textured surface of the urethane matrix to a composite material of rehydrating fibers and gypsum, while the composite material is still in a setting state; allow the composite material of fibers and gypsum to continue to set, thereby causing the textured surface of the urethane matrix to produce a textured surface in the composite material of fibers and gypsum; and removing the urethane matrix from the composite material before complete setting. . A method for producing a textured product, characterized in that it comprises the steps of: calcining gypsum to form acicular crystalline calcium sulfate hemihydrate in the presence of wood fibers to form a sludge; Dehydrate the sludge to remove a majority of the water content and form a cake mat " filter; reduce the temperature of the mat to the rehydration temperature of calcined gypsum; press the filter cake mat to remove additional water; re-pressurizing the filter cake mat by imposing a flexible textured matrix on the filter cake mat while the mat is forging and folding; allow the mat to partially set during the re-press stage; remove the contact mat with the textured flexible matrix; and continue setting the mat until it is completely set with the negative of the textured matrix on top. The method according to claim 4, characterized in that the step of removing comprises removing the contact mat when the mat has reached from about 40% to about 70% of final setting. The method according to claim 4, characterized in that the step of re-pressing comprises re-pressing with a textured flexible matrix made of urethane. The method according to claim 6, characterized in that the step of re-pressing comprises re-pressing with a textured flexible matrix comprising a layer of urethane. The method according to claim 6, characterized in that the step of re-pressing comprises re-pressing with a textured flexible matrix comprising an endless band of urethane. 9. A method for creating flexible, lightweight matrices for imparting surface texture to gypsum board that sets, characterized in that it comprises the steps of: preparing a master panel with a textured surface; apply a urethane coating to the textured surface of the master panel, whereby the urethane fills the textured surface of the master panel; cure urethane; and separating the urethane form from the master panel, thereby forming a lightweight flexible matrix with a textured surface on one side. A method according to claim 9, characterized in that the step of preparing a master panel with a textured surface includes the step of: applying a texturing compound to an outer surface of the master panel. 11. A method according to claim 10, characterized in that it also includes the step of imparting textured relief to the texturizing compound. 12. A method according to claim 11, characterized in that it also includes the step of drying the texturizing compound. 13. A method according to claim 9, characterized in that the step of preparing a master panel with a textured surface includes the step of preparing a master panel with a surface relief on its outer surface in the form of a splash-covered texture (tirol) . A method according to claim 9, characterized in that the step of preparing a master panel with a textured surface includes the step of preparing a master panel with a surface relief on its outer surface in the form of a wood grain. A method according to claim 9, characterized in that the step of preparing a master panel with a textured surface includes the step of preparing a master panel with a surface relief on its outer surface in the form of edge tapers so that panels are cut from fibreboard and plasterboard. 16. A method according to claim 9, characterized in that the step of preparing a master panel with a textured surface includes the step of preparing a master panel surface with surface reliefs on its outer surface in the form of a wood covering. 17. A method for producing textured fiberboard and gypsum board, characterized in that it comprises the steps of: mixing ground gypsum and host particles of a fibrous reinforcing material and liquid sufficient to produce a diluted sludge consisting of at least about 70% liquid by weight; calcining the gypsum, in the presence of the host particles, by heating under pressure and forming calcium sulfate hemihydrate; separating a main portion of the liquid from the calcined gypsum and host particles to form a filter cake; reduce the temperature of the filter cake to the rehydration temperature of the calcium sulfate hemihydrate; First press the filter cake to form a board and remove additional water from there; provide a matrix that has a texture; in second press the texture of the matrix centers the board, while the board is forging and folding; and separating the board from the matrix at a point in the rehydration, where the board temperature is not greater than about half the temperature increase between the rehydration temperature and the highest temperature reached during rehydration. 18- The method according to claim 17, characterized in that the separation step occurs when the board temperature is in the range of about 25% -60% of the temperature increase between the rehydration temperature and the highest temperature. 19. A method for producing a textured fiber and gypsum composite material, characterized in that it comprises the steps of: providing a urethane on a master surface having a relief; cure urethane; removing the urethane from the master surface and forming a flexible matrix having surface relief; applying the surface relief of the urethane matrix to a composite material of rehydrated calcined gypsum and gypsum, while the composite material is forging and folding; allow the composite material of fibers and gypsum to continue to rehydrate and set, causing the relief surface of the urethane matrix to form a relief surface in the composite material of fibers and gypsum, and to remove the urethane matrix from the composite material. a temperature of the composite material, no greater than about 60% of the temperature increase between the rehydration temperature and the maximum temperature reached during rehydration. 20. A method for producing a textured board, characterized in that it comprises the steps of calcining gypsum to form calcium sulfate hemihydrate in the presence of wood fibers and water to form a sludge; Dehydrate the sludge to remove a majority of the free water content and form a filter cake mat; reduce the temperature of the filter cake to the rehydration temperature of the calcium sulfate hemihydrate; press the filter cake mat to remove additional water and form a board; re-pressing the board by imposing a textured matrix on the board while the board is foldable and rehydration occurs; allow the board to partially set during the re-press stage; and removing the contact board with the textured matrix at a temperature no greater than about half the temperature between the rehydration start temperature and the highest rehydration temperature. The method according to claim 20, characterized in that the step of re-pressing comprises re-pressing a textured flexible matrix which is a layer of material. 22. The method according to claim 20, characterized in that the step of re-pressing comprises re-pressing a textured flexible matrix that is an endless band. 23. The method according to claim 20, characterized in that the step of re-pressing comprises re-pressing a textured flexible matrix comprising urethane. The method according to claim 20, characterized in that the step of re-pressing begins after the filter cake mat reaches from about 10% to about 25% of the increase between the rehydration temperature and the rehydration temperature. high. 25. The method according to claim 20, characterized in that the step of removing is carried out on the rise curve of exothermic reaction temperature of the rehydration material at a point from about 25% to about 60% of the temperature increase. from the beginning of rehydration to the highest point of the exothermic reaction temperature curve. 26. The method according to claim 25, characterized in that the temperature rise curve has a portion with a substantially constant slope and the step of removing occurs at a point on it. 27. The method according to claim 20, characterized in that the step of removing the contact board with the textured matrix occurs when the board is approximately 40% to approximately 70% fully rehydrated. 28. The method according to claim 27, characterized in that the board is set sufficiently so that the moderate pressure of a person's finger leaves no impression. 29. A product made by the method of claims 1, 3, 4, 9, 17, 19 or 20.