Plaster board and method for producing same

Abstract

The present disclosure relates to a plasterboard comprising: a first panel having an outer surface, an inner surface, a first edge, a second edge, and a center between the first edge and the second edge; a layer of hardened plaster material coupled to the inner surface of the first panel, where the hardened plaster material has a first density proximate the first edge of the first panel and a second density proximate the center of the first panel, the first density being greater than the second density; and a second panel having an outer surface, an inner surface, a first edge, a second edge, and a center between the first edge and the second edge, where the second panel is coupled to the hardened plaster material opposite the first panel.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims the benefit of priority to U.S. Provisional Patent Application No. 63 / 294,616, filed on December 29, 2021, the entire contents of which are hereby incorporated by reference herein. Background Art 1. Technical Field

[0003] The present disclosure generally relates to plasterboards and methods for making plasterboards. The present disclosure more particularly relates to plasterboards having higher density portions disposed adjacent to edges thereof. 2. Technical Background

[0005] Plasterboard, commonly referred to as "sheet" or "drywall," is commonly used to construct walls within homes, businesses, or other buildings. Plasterboard is typically made of gypsum, but other materials, including lime and cement, are also used. A typical process for making plasterboard involves dispensing and spreading a plaster material (e.g., a slurry of gypsum in water) onto a sheet of paper or fiberglass mat on a platform, and covering the plaster material with another sheet of paper or fiberglass mat. The sandwich is fed through rollers to provide the structure with the desired thickness, and then cured to form a hardened plaster material disposed between the two sheets of paper or fiberglass. The plasterboard may be cut into sections of predetermined length and width that meet acceptable construction standards.

[0006] Various methods are used to reduce the weight of plasterboard by reducing the density of the plaster material. One such method is foaming, where air bubbles are introduced into the wet slurry before application to a sheet of fiberglass mat. However, reducing the density of the plaster material may result in a weaker plasterboard.

[0007] In some methods, a first, high-density, thin coat of slurry is applied to a sheet of fiberglass mat. A second, main layer of lower-density slurry is applied to the thin coat. The thin coat provides increased strength, particularly higher nail pulls, compared to a plasterboard made entirely of low-density plaster material. However, the addition of the thin coat increases the weight of the plasterboard. In addition, the wet thin coat may be pushed out of place during application of the main layer of slurry. This foot wash or flushing of the thin coat may result in uneven nail pull ratings for the plasterboard.

[0008] Therefore, what is needed is an improved plasterboard having both sufficient strength and reduced weight. There is also a need for an improved method and process for making such a plasterboard. Summary of the invention

[0009] One aspect of the present disclosure is a plasterboard comprising:

[0010] a first panel having an outer surface, an inner surface, a first edge, a second edge, and a center between the first edge and the second edge;

[0011] a layer of hardened plaster material coupled to the inner surface of the first panel, wherein the hardened plaster material has a first density proximate the first edge of the first panel and a second density proximate the center of the first panel, the first density being greater than the second density; and

[0012] A second panel has an outer surface, an inner surface, a first edge, a second edge, and a center between the first edge and the second edge, wherein the second panel is coupled to the hardened stucco material opposite the first panel.

[0013] Another aspect of the present disclosure is a method of making a plasterboard, the method comprising:

[0014] unrolling a first panel of material from a first roll;

[0015] applying a first line of stucco slurry to a top surface of the first panel material proximate a first edge of the first panel material;

[0016] applying a second line of stucco slurry to the top surface of the first panel material proximate a second edge of the first panel material;

[0017] applying a third stucco slurry line to the top surface of the first panel material between the first stucco slurry line and the second stucco slurry line, wherein the third stucco slurry line has a lower density than the first stucco slurry line; and

[0018] A second panel material is applied to the top surface of the third stucco slurry line.

[0019] Other aspects of the present disclosure will be apparent from the disclosure herein. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The accompanying drawings are included to provide a further understanding of the methods and apparatus of the present disclosure, and are incorporated into and constitute a part of this specification. The drawings are not necessarily drawn to scale, and the dimensions of various elements may be distorted for clarity. The accompanying drawings illustrate one or more embodiments of the present disclosure and together with the description serve to explain the principles and operations of the present disclosure.

[0021] Figure 1 is a top perspective view of a plasterboard according to one embodiment of the present disclosure.

[0022] Figure 2 yes Figure 1 Cross-sectional view of a plasterboard.

[0023] Figure 3 A method of manufacturing a plasterboard according to one embodiment of the present disclosure is illustrated.

[0024] Figure 4 A method of manufacturing a plasterboard according to one embodiment of the present disclosure is illustrated. DETAILED DESCRIPTION

[0025] The inventors have noted the shortcomings of existing processes for forming plasterboards having plaster materials of varying densities disposed therein. Conventional plasterboards are formed between sheets of paper or fiberglass mats. A slurry of plaster material is applied to the inner surface of a first sheet. The applied slurry is smoothed to a uniform thickness using one or more rollers. A second sheet of paper or fiberglass is then applied on top of the slurry, thereby sandwiching the slurry between the two sheets. However, the slurry, and therefore the resulting board, has an overall uniform density and strength along the surface of the first sheet. In order for the board to have sufficient strength in areas where large nail pulls are required (such as near the edge of the board), the overall strength of the plaster material is higher than that required at other locations (such as near the center of the board).

[0026] Thus, one aspect of the present disclosure is a plasterboard having a first surface and an opposing second surface. The plasterboard includes a body of hardened plaster material extending from the first surface of the plasterboard to the second surface of the plasterboard. The hardened plaster material has a first density near a first edge of the plasterboard and a second density near a center of the plasterboard, wherein the first density is higher than the second density. The hardened plaster material also has a third density near the second edge of the plasterboard, wherein the third density is substantially similar to the first density. At the center of the board, the density of the hardened plaster material is substantially similar along the thickness of the board. As will be described in more detail below, such a plasterboard can be produced by applying two streams of higher density slurry near the respective edges of a first sheet of paper and applying a stream of lower density slurry near the center of the first sheet of paper.

[0027] Relative to Figure 1 to Figure 2 Describing one embodiment of such a plasterboard, the figure shows two views of a plasterboard 100 . Figure 1 is an xy plane diagram of the plasterboard 100 . Figure 2 is an xz plane view of the plasterboard 100. The plasterboard 100 includes opposing surfaces 102 and 104, a body of hardened plaster material 106 (including a lower density portion of hardened plaster material 107A and two higher density portions of hardened plaster material 107B). Figure 2As shown, there is no clear boundary between the lower density hardened plaster material 107A and the higher density hardened plaster material 107B. Instead, the two plaster materials are partially mixed in the transition stage, forming a density gradient between the higher density hardened plaster material 107B and the lower density hardened plaster material 107A.

[0028] The body of hardened stucco material 106 may extend from surface 102 to surface 104 on opposite sides of the stucco board 100. The hardened stucco material 106 also extends from a first edge 114 to a second edge 115 of the stucco board 100. At any given point in the xy plane, the density of the hardened stucco material 106 is substantially similar along the z-direction (through the thickness of the stucco board 100).

[0029] As will be appreciated by those of ordinary skill in the art, the plasterboards described herein can be prepared using a variety of different inorganic base materials. For example, in various embodiments of the plasterboards and methods described herein, the plaster material includes a base material that is a gypsum material. In other embodiments of the plasterboards and methods described herein, the plaster material includes a base material such as lime or cement. The hardened plaster material can include one or more fillers or additives in the base plaster material, such as glass fibers, plasticizer materials, foaming agents, and / or ethylenediaminetetraacetic acid (EDTA). In some embodiments, additional materials are dispersed within the plaster material. For example, a layer of damping material can be included within the plaster material 106. Statements regarding the density of the plaster material 106 do not necessarily apply to additional layers of material therein.

[0030] The plasterboards of the present disclosure can be made in various thicknesses. One of ordinary skill in the art will select the desired thickness for a particular end use. In various embodiments of the plasterboards and methods described herein, the total thickness of the plasterboard (i.e., along the Figure 1 In some embodiments, the total thickness of the plasterboard is substantially equal to 0.375 inches. In other specific embodiments, the total thickness of the plasterboard is substantially equal to 0.5 inches. In other specific embodiments, the total thickness of the plasterboard is substantially equal to 0.625 inches. And in still other specific embodiments, the total thickness of the plasterboard is substantially equal to one inch (e.g., particularly when a lower density plaster material is used).

[0031] The hardened plaster material 106 is positioned between two sheets or panels, a front panel 116 and a rear panel 117. As will be appreciated by one of ordinary skill in the art, lengths of paper, fiberglass mat or fabric, or other backing material form the front panel 116 and the rear panel 117. During manufacture, one of the front panel 116 or the rear panel 117 may be placed on a platform so that the wet plaster material is dispensed and spread onto the backing material. In such embodiments, the paper, fiberglass, or other backing material will remain at the surface of the plasterboard, as is conventionally done with wallboard materials.

[0032] As described above, the use of foaming or additives within the plaster material can help improve several properties of the plasterboard. This can be used to produce a plaster material with a relatively low density, thereby producing a plasterboard that is light and therefore desirable to the installer. However, such a low-density plaster material may have relatively poor properties compared to a higher-density material. But using a hardened plaster material with different densities along the width of the plasterboard can improve such properties (e.g., nail pull force). In various embodiments, the density of the hardened plaster material is between 0.40 g / cm 3 Up to 0.65g / cm 3 within the range.

[0033] Based on the disclosure herein, one of ordinary skill in the art will provide a first density (i.e., near the first edge of the first panel) that is significantly greater than the second density (near the center of the first panel) in order to enjoy the various benefits as described herein. For example, in various embodiments further described herein, the first density is at least 110% of the second density, for example, at least 120% of the second density. In various embodiments further described herein, the first density is at least 130% of the second density, for example, at least 140% of the second density. In various such embodiments, the first density is no greater than 300% of the second density, for example, no greater than 200% of the first density. For example, in various embodiments, the first density is in the range of 110% to 300% of the second density, such as in the range of 120% to 300%, or 130% to 300%, or 140% to 300%, or 150% to 300%, or 110% to 200%, or 120% to 200%, or 130% to 200%, or 140% to 200%, or 150% to 200% of the second density.

[0034] However, one of ordinary skill in the art will appreciate that the presently disclosed methods and panels can have a variety of thicknesses and weights. However, the weight of the plasterboards described herein is generally lighter than conventional plasterboards of the same size and of comparable strength. For example, the thickness of the panel can be 3 / 8" and the dry weight can be less than 1400lb / MSF (MSF=1000 square feet). In other examples, the thickness of the panel can be 3 / 8" and the dry weight can be less than 1350lb / MSF. One of ordinary skill in the art will appreciate that the weight of the plasterboard increases with the thickness of the plasterboard. In some embodiments, the dry weight of the panel is less than 467lb / MSF per 1 / 8" thickness. In some examples, the dry weight of the panel is less than 450lb / MSF per 1 / 8" thickness.

[0035] Figure 3 A simplified manufacturing system 300 for producing a plasterboard 100 is illustrated. The manufacturing system 300 includes a roll 316 of a front panel material 116, a roll 317 of a back panel material 117, and slurry application devices 307A, 307B. In some applications, the manufacturing system 300 also includes one or more adhesive application devices to apply adhesive between the layers of the plasterboard to bond the plaster material 106 to the front panel 116 and / or the back panel 117.

[0036] During production, the front panel 116 is unrolled from the roll 316 with the outer surface 104 facing downward to form the bottom layer of the laminate. One or more applicators 307B apply a first edge layer 306B of a plaster material slurry (such as a stucco slurry) to the inner surface of the front panel 116. The plaster material slurry 306B is a relatively high density plaster material slurry, or a plaster material slurry with a relatively low foam content. As used herein, the "density" of the plaster slurry material is not the density of the slurry itself, but the density of the material in the slurry when it is transformed into a final set and dried board. One or more applicators 307B apply a line of the plaster material slurry 306B to each edge of the front panel 116 (such as Figure 1 to Figure 2 116). In some embodiments, the one or more applicators 307B include two applicators 307B, each of which applies a line of stucco slurry material 306B near a respective edge of the front panel 116. In alternative embodiments, the one or more applicators 307B include a single applicator having two or more nozzles, wherein at least one nozzle is positioned to apply a line of stucco material slurry 306B near a respective edge of the front panel 116. In some embodiments, additional equipment is positioned inline after the applicators 307B to smooth the slurry 306B into a layer having a uniform thickness.

[0037] One or more application devices 307A apply the plaster material slurry 307A to the top surface of the front panel 116 between the lines of the two plaster material slurries 307B. The system 300 may include a smoothing device in line after the second application device 307A for smoothing the plaster material slurry 307A into a uniform layer. In some examples, a single smoothing device is placed in line after the second application device 307A and is used to smooth both the plaster material slurries 307A and 307B. In an alternative form, before applying the plaster material slurry 307A, one or more first smoothing devices are used to smooth the plaster material slurry 307B. Then, a second smoothing device is used to smooth the plaster material slurry 307A.

[0038] In some examples, the second applicator 307A applies the plaster material slurry 307A before the plaster material slurry 307B dries. Therefore, the plaster material slurries 307A and 307B are partially mixed near the inner edge of the line of the two plaster material slurries 307B, thereby forming a transition area between the plaster material slurry 307B and the plaster material slurry 307A.

[0039] Alternatively or additionally, a component is added to one or both of the plaster material slurries 307A and 307B to assist in bonding therebetween and / or between the plaster material slurries 307A and 307B and the front and rear panels 116 and 117. In some forms, the bonding material comprises dextrose (e.g., in an amount of 1 lbs / MSF to 3 lbs / MSF). The addition of a bonding material (e.g., dextrose) increases the speed at which the materials bond, thereby allowing the plaster material slurries 307A and 307B to dry faster, reducing the manufacturing time of the plasterboard 100.

[0040] The rear panel 117 is unrolled from the roll 317 and applied to the top surface of the plaster material slurry 307A and 307B to form the plaster board 100. Figure 3 The illustrated embodiment has the front panel 116 forming the bottom of the laminate, but it will be appreciated that the rolls 316 and 317 may be interchanged such that the bottom layer is formed by the back panel 117 .

[0041] Figure 4 A simplified manufacturing system 400 for manufacturing a plasterboard, such as the plasterboard 100 described above, is illustrated. Figure 4 is an end view of manufacturing system 400 showing a cross section of front panel 116 near the location of applicators 307A and 307B. In some forms, manufacturing system 400 is the same as manufacturing system 300 described above.

[0042] The manufacturing system 400 includes two or more nozzles or applicators 307B for applying a slurry of plaster material near the edges 114 and 115 of the front panel 116. The manufacturing system 400 also includes an applicator 307B positioned to apply the slurry of plaster material near the center of the front panel 116 (i.e., midway between the edges 114 and 115). Although the applicators 307A and 307B appear to be positioned at the same point along the length of the front panel 116, it should be understood that the applicator 307A may be positioned downstream of the applicator 307B, such as Figure 3 Alternatively, applicator 307A may be placed upstream of applicator 307B.

[0043] A series of guides or rollers 401A-D contact the front panel 116 to form a recessed section, such as a channel or groove, therein. In the illustrated embodiment, a first guide 401A is placed near the first edge 114 of the front panel 116. The first guide 401A presses the bottom surface 104 of the front panel 116 upward. A second guide 401B is placed between the first edge 114 and the center of the front panel 116. The second guide 401B also pushes the bottom surface 104 of the front panel 116 upward. The first two guides 401A and 401B form an edge channel 407B between them. An applicator 307B is placed above the edge channel 407B to apply a slurry of plaster material into the edge channel 407B.

[0044] Similarly, the fourth guide 401D is placed near the second edge 115 of the front panel 116. The fourth guide 401D presses the bottom surface 104 of the front panel 116 upward. The third guide 401C is placed between the second edge 115 and the center of the front panel 116. The third guide 401C also pushes the bottom surface 104 of the front panel 116 upward. The two guides 401C and 401D form an edge channel 407B therebetween. The applicator 307B is placed above the edge channel 407B so as to apply the plaster material slurry into the edge channel 407B.

[0045] In some embodiments, the second guide 401B and the third guide 401C form a central channel 407A between them. The applicator 307A applies the plaster material slurry into the central channel 407A. In some embodiments, one or more additional rollers or guides are placed between each of the second guide 401B and the third guide 401C and the center of the front panel 116. These additional rollers or guides form the central channel 407A.

[0046] Alternatively or additionally, guides or rollers may be placed to press down on the top or inner surface of the front panel 116. The guides or rollers are placed near the center of the channels 407A and 407B and are used to form the channels 407A and 407B.

[0047] In some embodiments, guides 401A-D each include one or more rollers configured to contact the surface of front panel 116. When the front panel moves along manufacturing system 400, rollers 401A-D rotate due to friction between rollers 401A-D and front panel 116, thereby reducing wear on front panel 116. In other embodiments, guides 401A-D include static guides. Static guides 401A-D may include one or more fingers that contact front panel 116 at specific points within manufacturing system 400. In some forms, static guides are elastic and are configured to deform or bend according to contact with front panel 116. Alternatively, static guides 401A-D include elongated guides, such as walls or tracks, extending along the length of manufacturing system 400. The length of manufacturing system 400 with elongated static guides 401A-D includes one or more application devices 307A and / or 307B.

[0048] In some embodiments, the manufacturing system 400 includes one or more additional rollers or guides placed downstream of the guides 401A-D. The additional rollers or guides contact a relatively wide portion of the bottom surface 104 of the front panel 116 near one or more of the channels 407A and / or 407B. The rollers or guides level the front panel 116, thereby removing the channels 407A and / or 407B. In some forms, the leveling rollers or guides are placed relative to the rollers placed above the front panel 116 for smoothing the plaster material slurry. In this way, squeezing the plaster material slurry and the front panel between the guides or rollers makes the front panel 116 and the slurry assembly have a uniform thickness.

[0049] In some forms, the plaster material slurry is applied and smoothed in stages. In these examples, the first set of guides 401A-D forms an edge channel 407B. The applicator 307B applies the plaster material slurry into the edge channel 407B. Downstream of the applicator 307B, one or more leveling guides or rollers and one or more smoothing rollers remove the channel 307B and smooth the plaster material slurry near the edges 114 and 115 of the front panel.

[0050] Further downstream, additional guides, such as guides 401B-C, form a central channel 407A. Applicator 307A applies stucco material slurry into central channel 407A. Downstream of applicator 307A, leveling rollers or guides and smoothing rollers remove central channel 407A and smooth the stucco material slurry.

[0051] Applicator 307B and applicator 307A are configured to apply different stucco material slurries onto front panel 116. Specifically, applicator 307B is configured to apply a relatively high density stucco material slurry, and applicator 307A is configured to apply a relatively low density stucco material slurry.

[0052] The manufacturing system 400 includes a slurry mixer 430. The slurry mixer 430 is configured to mix the wet components and the dry components of the plaster material to form a relatively uniform slurry. In some forms, the slurry mixer 430 includes one or more inlets through which the components of the plaster material are added. The one or more inlets are computer controlled so that the formula of the plaster material can be electronically adjusted. For example, the slurry mixer 430 includes an adjustable water inlet. The water inlet can be adjusted to change the water content of the plaster material slurry.

[0053] The slurry mixer 430 includes one or more outlets leading to the applicator 307B. As described above, the applicator 307B applies the slurry mixture from the slurry mixer to the front panel 116. The slurry mixer 430 includes an additional outlet leading to a foaming chamber 435. The foaming chamber 435 is used to reduce the density of the slurry mixture. In some forms, the foaming chamber 435 includes an inlet through which the aqueous foam is added to the slurry mixture. Mixing the aqueous foam and the slurry mixture forms a foamed slurry mixture, which has a lower density than the unfoamed slurry mixture applied by the applicator 407B. Alternatively or additionally, the foaming chamber 435 includes a ventilation device. The ventilation device introduces a gas (e.g., ambient air) into the slurry mixture so that bubbles are formed therein, thereby foaming the slurry mixture.

[0054] The foaming chamber 435 is operably coupled to the applicator 307A. The applicator 307A applies the foamed slurry mixture from the foaming chamber to the front panel 116.

[0055] In some embodiments, the manufacturing system 400 includes a plurality of slurry mixers 430. The first slurry mixer 430 is used to mix slurry for use by the application device 307A. The second slurry mixer 430 is used to mix slurry for use by the application device 307B. Thus, different slurry mixtures can be used for the center portion of the stucco material and the edge portion of the stucco material. Using separate mixtures allows for further variation between the two stucco material slurries.

[0056] The plaster material slurry mixture has several components and properties that can be adjusted. As described above, the use of at least two different plaster material slurries allows the use of a lower density plaster material slurry near the center of the plasterboard 100. The process also allows the use of a lower moisture slurry compared to previous plasterboard manufacturing processes. The use of a lower moisture slurry allows the plaster material slurry to dry faster, thereby reducing the manufacturing time of the plasterboard 100.

[0057] In some examples, the average moisture content of the plaster material slurry is less than 25%. In some forms, the average moisture content of the plaster material slurry is less than 20%. In some forms, the average moisture content of the plaster material slurry is less than 15%. In some forms, the average moisture content of the plaster material slurry is less than 10%. In some forms, the average moisture content of the plaster material slurry is between 5% and 15%. In some forms, the average moisture content of the plaster material slurry is between 5% and 10%. The moisture content of the plaster material slurry can be different between the edge and the center of the plasterboard 100. In some examples, the plasterboard has a moisture content of less than 10% near the edge and a moisture content of greater than 10% near the center.

[0058] The plaster material slurry contains soap to assist in foaming. In some forms, the plaster material slurry contains soap in an amount between 0.2% and 0.5%. In some forms, the plaster material slurry contains soap in an amount between 0.25% and 0.45%. In some forms, the plaster material slurry contains soap in an amount between 0.25% and 0.35%.

[0059] In some examples, the foam density of the lower density plaster material slurry is higher than 70 g / l. In some examples, the foam density of the lower density plaster material slurry is higher than 75 g / l. In some examples, the foam density of the lower density plaster material slurry is between 80 g / l and 90 g / l.

[0060] The composition of the stucco material slurry enables the manufacturing system to apply the slurry to the front panel 116 at a faster rate than previous manufacturing systems. In some forms, the manufacturing system applies the slurry to the front panel movement 116 moving at more than 150 fpm. In some forms, the manufacturing system applies the slurry to the front panel movement 116 moving at more than 175 fpm. In some forms, the manufacturing system applies the slurry to the front panel movement 116 moving at more than 180 fpm. In some forms, the manufacturing system applies the slurry to the front panel movement 116 moving between 180 fpm and 200 fpm.

[0061] As described above, the first stucco slurry line (which provides material at the first edge of the stucco board) has a higher density than the third stucco slurry line (which provides material at the central area of ​​the stucco board). For example, in various embodiments, the density of the first stucco slurry line is at least 120%, such as at least 130%, of the density of the third stucco slurry line. In various embodiments, the density of the first stucco slurry line is at least 140%, such as at least 150%, of the density of the third stucco slurry line. However, in various embodiments, the density of the first stucco slurry line is no greater than 300%, such as no greater than 225%, or no greater than 200%, of the density of the third stucco slurry line. For example, in various embodiments, the density of the first stucco slurry line is in the range of 120% to 300% of the density of the third stucco slurry line, such as in the range of 130% to 300%, or 140% to 300%, or 150% to 300%, or 120% to 225%, or 130% to 225%, or 140% to 225%, or 150% to 225%, or 120% to 200%, or 130% to 200%, or 140% to 200%, or 150% to 200% of the density of the third stucco slurry line.

[0062] Similarly, in various embodiments, the second stucco slurry line (which provides material at the second edge of the stucco board) has a higher density than the third stucco slurry line (which provides material at the center area of ​​the stucco board). For example, in various embodiments, the density of the second stucco slurry line is at least 120%, such as at least 130%, of the density of the third stucco slurry line. In various embodiments, the density of the second stucco slurry line is at least 140%, such as at least 150%, of the density of the third stucco slurry line. However, in various embodiments, the density of the second stucco slurry line is no greater than 300%, such as no greater than 225%, or no greater than 200%, of the density of the third stucco slurry line. For example, in various embodiments, the density of the second stucco slurry line is in the range of 120% to 300% of the density of the third stucco slurry line, such as in the range of 130% to 300%, or 140% to 300%, or 150% to 300%, or 120% to 225%, or 130% to 225%, or 140% to 225%, or 150% to 225%, or 120% to 200%, or 130% to 200%, or 140% to 200%, or 150% to 200% of the density of the third stucco slurry line.

[0063] The inventors have determined that using a denser plasterboard edge can improve nail pull force (i.e., for nails driven through the plasterboard at the edge of the plasterboard). In some examples, the plasterboard 100 has a nail pull force of at least 50 lbf for nails driven near the first edge (i.e., in the area of ​​the first density). In some examples, the plasterboard 100 has a nail pull force of at least 70 lbf. In some examples, the plasterboard 100 has a nail pull force of at least 75 lbf.

[0064] The inventors have also determined that by using a denser material at the edges of the panels as described herein, edge stiffness is advantageously improved.

[0065] Furthermore, the inventors have determined that using a denser material at the edges of the plates as described herein can provide a lower dryer heat load (eg, lower overall energy consumption in drying).

[0066] "MSF" means 1000 square feet. One of ordinary skill in the art would calculate the equivalent area in square meters by using the following conversion:

[0067] 1000ft 2 =92.903m 2 .

[0068] "lb" is an abbreviation for pounds and refers to U.S. pounds. One of ordinary skill in the art would calculate the equivalent mass in grams by using the following conversion:

[0069] 1lb=453.59g.

[0070] One of ordinary skill in the art will convert between inches (") and centimeters by using the following conversion:

[0071] 1"=2.54cm.

[0072] "lbf" is an abbreviation for pounds-force. One of ordinary skill in the art would use the following conversion to calculate the equivalent force in Newtons:

[0073] 1lbf=4.4482N.

[0074] The embodiments listed below provide various aspects and embodiments of the present disclosure, and the listed embodiments may be combined in any number and in any combination that is not logically or technically inconsistent.

[0075] Embodiment 1. A plasterboard, comprising:

[0076] a first panel having an outer surface, an inner surface, a first edge, a second edge, and a center between the first edge and the second edge;

[0077] a layer of hardened stucco material coupled to the inner surface of the first panel, wherein the hardened stucco material has a first density proximate the first edge of the first panel and a second density proximate the center of the first panel, the first density being greater than the second density; and

[0078] A second panel has an outer surface, an inner surface, a first edge, a second edge, and a center between the first edge and the second edge, wherein the second panel is coupled to the hardened stucco material opposite the first panel.

[0079] Embodiment 2. The stucco board of embodiment 1, wherein the hardened stucco material has a third density proximate the second edge of the first panel, the third density being substantially similar to the first density.

[0080] Embodiment 3. The plasterboard of any one of Embodiments 1 to 2, wherein the density of the hardened plaster material is approximately equal to the second density near the center of the first panel, near the center of the second panel, and midway between the center of the first panel and the center of the second panel.

[0081] Embodiment 4. The stucco board of any one of Embodiments 1 to 3, wherein the stucco board has a dry weight of less than 467 lb / MSF per 1 / 8" thickness.

[0082] Embodiment 5. The stucco board of any one of Embodiments 1 to 4, wherein the stucco board has a dry weight of less than 450 lb / MSF per 1 / 8" thickness.

[0083] Embodiment 6. The stucco board of any one of Embodiments 1 to 5, wherein the hardened stucco material comprises dextrose.

[0084] Embodiment 7. The plasterboard of any one of Embodiments 1 to 6, wherein the plasterboard has a nail pull of at least 70 lbf.

[0085] Embodiment 8. The plasterboard of any one of Embodiments 1 to 7, wherein the plasterboard has a nail pull of at least 75 lbf.

[0086] Embodiment 9. The plasterboard of any one of Embodiments 1 to 8, wherein the first density is at least 110% of the second density, such as at least 120% of the second density.

[0087] Embodiment 10. The plasterboard of any one of Embodiments 1 to 8, wherein the first density is at least 130% of the second density, such as at least 140% of the second density.

[0088] Embodiment 11. The plasterboard of any one of Embodiments 1 to 10, wherein the first density is no greater than 300% of the second density, such as no greater than 200% of the second density.

[0089] Embodiment 12. The plasterboard of any one of Embodiments 1 to 8, wherein the first density is in the range of 110% to 300% of the second density, for example, in the range of 120% to 300%, or 130% to 300%, or 140% to 300%, or 150% to 300%, or 110% to 200%, or 120% to 200%, or 130% to 200%, or 140% to 200%, or 150% to 200% of the second density.

[0090] Embodiment 13. A method of making a plasterboard, the method comprising:

[0091] providing a first panel material (e.g., by unrolling it from a first roll);

[0092] applying a first line of stucco slurry to a top surface of the first panel material proximate a first edge of the first panel material;

[0093] applying a second line of stucco slurry to the top surface of the first panel material proximate a second edge of the first panel material;

[0094] applying a third stucco slurry line to the top surface of the first panel material between the first stucco slurry line and the second stucco slurry line, wherein the third stucco slurry line has a lower density than the first stucco slurry line; and

[0095] A second panel material is applied to the top surface of the third stucco slurry line.

[0096] Embodiment 14. A method according to embodiment 13, the method also includes: bending the first panel material to form a first edge channel near the first edge of the first panel material, wherein applying the first plaster slurry line includes applying the first plaster slurry line into the first edge channel.

[0097] Embodiment 15. A method according to any one of Embodiments 13 to 14, the method further comprising: bending the first panel material to form a center channel between the first edge and the second edge of the first panel material, wherein applying the third mortar slurry line comprises applying the third mortar slurry line into the center channel.

[0098] Embodiment 16. The method of any one of Embodiments 13 to 15, further comprising: foaming the slurry mixture to form a foamed slurry mixture, wherein applying the third stucco slurry line comprises applying the foamed slurry mixture.

[0099] Embodiment 17. The method of Embodiment 16, wherein applying the first stucco slurry line comprises applying the slurry mixture prior to foaming.

[0100] Embodiment 18. The method of any one of Embodiments 13 to 17, wherein the third stucco slurry line comprises a soap content between 0.25% and 0.35%.

[0101] Embodiment 19. The method of any one of Embodiments 13 to 18, wherein the plasterboard has an average moisture content of less than 25%.

[0102] Embodiment 20. The method of any one of Embodiments 13 to 19, wherein the plasterboard has an average moisture content of less than 10%.

[0103] Embodiment 21. The method of any one of Embodiments 13 to 20, wherein the third stucco slurry line has a higher water content than the first stucco slurry line.

[0104] Embodiment 22. The method of any one of Embodiments 13 to 21, wherein the third stucco slurry line has a foam density of at least 70 g / l.

[0105] Embodiment 23. The method of any one of Embodiments 13 to 22, wherein the third stucco slurry line has a foam density between 80 g / l and 90 g / l.

[0106] Embodiment 24. The method of any one of Embodiments 13 to 23, wherein the third stucco slurry line comprises dextrose.

[0107] Embodiment 25. The method of any one of Embodiments 13 to 24, wherein the first stucco slurry line comprises dextrose.

[0108] Embodiment 26. The method of any one of Embodiments 13 to 25, further comprising: applying an adhesive to the inner surface of the first panel material.

[0109] Embodiment 27. The method of any one of Embodiments 13 to 26, further comprising: applying an adhesive to the inner surface of the second panel material.

[0110] Embodiment 28. The method of any one of Embodiments 13 to 27, further comprising smoothing the first stucco slurry line before applying the third stucco slurry line.

[0111] Embodiment 29. The method of any one of Embodiments 13 to 28, wherein the density of the first stucco slurry line is at least 120%, such as at least 130%, of the density of the third stucco slurry line.

[0112] Embodiment 30. The method of any one of Embodiments 13 to 28, wherein the density of the first stucco slurry line is at least 140%, such as at least 150%, of the density of the third stucco slurry line.

[0113] Embodiment 31. The method of any one of Embodiments 13 to 30, wherein the density of the first stucco slurry line is no greater than 300%, e.g., no greater than 225% or no greater than 200%, of the density of the third stucco slurry line.

[0114] Embodiment 32. A method according to any one of Embodiments 13 to 28, wherein the density of the first stucco slurry line is in the range of 120% to 300% of the density of the third stucco slurry line, for example, in the range of 130% to 300%, or 140% to 300%, or 150% to 300%, or 120% to 225%, or 130% to 225%, or 140% to 225%, or 150% to 225%, or 120% to 200%, or 130% to 200%, or 140% to 200%, or 150% to 200% of the density of the third stucco slurry line.

[0115] Embodiment 33. The method of any one of Embodiments 13 to 32, wherein the density of the second stucco slurry line is at least 120%, such as at least 130%, of the density of the third stucco slurry line.

[0116] Embodiment 34. The method of any one of Embodiments 13 to 32, wherein the density of the second stucco slurry line is at least 140%, such as at least 150%, of the density of the third stucco slurry line.

[0117] Embodiment 35. The method of any one of Embodiments 13 to 34, wherein the density of the second stucco slurry line is no greater than 300%, e.g., no greater than 225% or no greater than 200%, of the density of the third stucco slurry line.

[0118] Embodiment 36. A method according to any one of Embodiments 13 to 32, wherein the density of the second stucco slurry line is in the range of 120% to 300% of the density of the third stucco slurry line, for example, in the range of 130% to 300%, or 140% to 300%, or 150% to 300%, or 120% to 225%, or 130% to 225%, or 140% to 225%, or 150% to 225%, or 120% to 200%, or 130% to 200%, or 140% to 200%, or 150% to 200% of the density of the third stucco slurry line.

[0119] Embodiment 37. The plasterboard according to any one of embodiments 1 to 12, made according to the process of any one of embodiments 13 to 36.

[0120] Embodiment 38. The method of any one of Embodiments 13 to 36, wherein the plasterboard is a plasterboard according to any one of Embodiments 1 to 12.

[0121] It will be apparent to those skilled in the art that various modifications and variations may be made to the processes and devices described herein without departing from the scope of the present disclosure. Therefore, the present disclosure is intended to cover these modifications and variations of the present invention as long as they fall within the scope of the appended claims and their equivalents.

Claims

1. A plasterboard, comprising: a first panel having an outer surface, an inner surface, a first edge, a second edge, and a center between the first edge and the second edge; a layer of hardened stucco material coupled to the inner surface of the first panel, wherein the hardened stucco material has a first density proximate the first edge of the first panel and a second density proximate the center of the first panel, the first density being greater than the second density; and A second panel has an outer surface, an inner surface, a first edge, a second edge, and a center between the first edge and the second edge, wherein the second panel is coupled to the hardened stucco material opposite the first panel.

2. The plasterboard of claim 1 , wherein the hardened plaster material has a third density proximate the second edge of the first panel, the third density being substantially similar to the first density.

3. The plasterboard of claim 1 , wherein a density of the hardened plaster material is substantially equal to the second density near the center of the first panel, near the center of the second panel, and midway between the center of the first panel and the center of the second panel.

4. The plasterboard of claim 1 , wherein the plasterboard has a dry weight of less than 450 lb / MSF per 1 / 8" thickness.

5. The plasterboard of claim 1, wherein the plasterboard has a nail pull of at least 75 lbf.

6. The plasterboard of claim 1, wherein the first density is at least 110% of the second density.

7. The plasterboard of claim 1, wherein the first density is at least 130% of the second density.

8. The plasterboard of claim 1, wherein the first density is no greater than 200% of the second density.

9. A method of making a plasterboard, the method comprising: applying a first line of stucco slurry to a top surface of the first panel material proximate a first edge of the first panel material; applying a second line of stucco slurry to the top surface of the first panel material proximate a second edge of the first panel material; applying a third stucco slurry line to the top surface of the first panel material between the first stucco slurry line and the second stucco slurry line, wherein the third stucco slurry line has a lower density than the first stucco slurry line; as well as A second panel material is applied to the top surface of the third stucco slurry line.

10. The method according to claim 9, further comprising: The first panel material is bent to form a first edge channel proximate the first edge of the first panel material, wherein applying the first line of stucco slurry includes applying the first line of stucco slurry into the first edge channel.

11. The method according to claim 9, further comprising: The first panel material is bent to form a central channel between the first edge and the second edge of the first panel material, wherein applying the third stucco slurry line includes applying the third stucco slurry line into the central channel.

12. The method according to claim 9, further comprising: The slurry mixture is foamed to form a foamed slurry mixture, wherein applying the third stucco slurry line includes applying the foamed slurry mixture.

13. The method of claim 12, wherein applying the first stucco slurry line comprises applying the slurry mixture prior to foaming.

14. The method according to claim 9, further comprising: The first stucco slurry line is smoothed prior to applying the third stucco slurry line.

15. The method of claim 9, wherein the density of the first stucco slurry line is at least 120% of the density of the third stucco slurry line.

16. The method of claim 9, wherein the density of the first stucco slurry line is at least 140% of the density of the third stucco slurry line.

17. The method of claim 9, wherein the density of the first stucco slurry line is no greater than 300%, such as no greater than 225% or no greater than 200%, of the density of the third stucco slurry line.

18. The method of claim 9, wherein the density of the second stucco slurry line is at least 120% of the density of the third stucco slurry line.

19. The method of claim 9, wherein the density of the second stucco slurry line is at least 140% of the density of the third stucco slurry line.

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