ES2385357T3 - System and procedure for the manufacture of gypsum boards - Google Patents

Abstract

A process for the manufacture of gypsum boards (26), comprising: (a) providing an unfinished length of gypsum board (26) having a recess along longitudinal flanges transporting it on a conveyor in a first direction; (b) forming a plurality of recesses on a first surface of the gypsum board (26) by the step gradually decompressing the gypsum board (26), a lateral recess on each side edge of the unfinished length and at least one recess between , parallel to, and offset from, the side edges when the gypsum board (26) is transported in said direction generally parallel to the recess; and (c) cutting the unfinished length of the gypsum board (26) in the at least one offset side offset to form a plurality of finished lengths of gypsum board (26), such that each length of gypsum board (26) ) have lowered edges along the four edges of the first surface.

Description

System and procedures for the manufacture of drywall

Cross reference to related requests

The present application claims the priority of the provisional U.S. patent application. No. 60 / 736,123, filed November 9, 2005 and U.S. patent application. No. 11 / 345,349 filed on February 1, 2006.

Technical field

The present invention relates generally to gypsum boards, and more specifically to methods and to an apparatus for providing recessed portions at the side edges of a gypsum board.

Prior art

Conventional drywall or drywall are typically manufactured from a suspension of gypsum paste that is placed between two layers of paper. More specifically, in the conventional procedure, a wet plaster suspension is poured onto a conveyor between two layers of paper, and the suspension is allowed a certain amount of time to set. On gypsum board, the two layers of paper contain the suspension and provide the tensile strength required in installation and use.

In at least some known manufacturing processes, the conveyor is a closed loop conveyor that can travel at speeds of more than 120 meters per minute or faster. The conveyor allows the gypsum board to be manufactured using paper rolls and, consequently, includes at least one longitudinal edge forming system, a cutting system, and a drying system. The edge forming system uses raised wedge-shaped edges along the conveyor, which create recessed areas along the longitudinal edges on the face of the drywall before the drywall is completely cured. When the drywall is cut to size and installed later, the recesses are filled with a composite of drywall, adhesive tape is placed, and they are finished to produce a smooth joint.

The cutting system allows the gypsum board to be cut into predetermined discrete lengths so that substantially rectangular gypsum board elements are formed. The cutting system is adjustable to allow different lengths of drywall to be cut without substantial interruption of the manufacturing operation. After they have been cut, the drywall elements move away from the cutting station to a loading area where they are loaded into a drying system to dry the cut drywall elements.

Known gypsum boards include recessed areas that extend along both opposite longitudinal edges of the gypsum board. The recessed areas are formed by the raised edges on the conveyor. The recessed areas are in the form of inclined planes that narrow from the face of the drywall to the longitudinal edges and have a maximum depth at the lateral edges of approximately 2.29 mm (0.090 ") below the face of the board. gypsum When the gypsum board is cut by means of the cutting system, conventional gypsum board panels are formed that are surrounded by opposite recessed longitudinal edges and by a pair of non-recessed side edges that connect the longitudinal edges. The drywall is typically cut so that the panels are manufactured with a longitudinal length that is commonly eight feet (2.43 m), ten feet (3.04 m), twelve feet (3.65 m), fourteen feet (4.26 m) and sixteen feet (4.87 m), or more Additionally, gypsum board panels are made in thicknesses that are commonly 6.35 mm, 9.53 mm, 12.7 mm, 15.88 mm (1/4 ", 3/8", 1/2 "and 5/8") thick. For one m XIMA efficiency and conservation of floor space, the same line should be able to produce all different lengths of wallboard without significant stop line. During installation, depending on the length of the wall to be formed by the drywall, the drywall panels are typically placed for installation so that the longitudinal edges are parallel to the floor, an installation known as a "horizontal orientation". In this installation, a longitudinal recess of a first panel is adjacent to a longitudinal recess of the adjacent panel. This forms a longitudinal recessed joint. Then a composite filling material is used for gypsum board and a tape to seal the recessed joint formed by the recessed longitudinal edges of the panels. Specifically, the recessed areas of the joints are filled with the drywall compound, the tape is placed and smoothed through the joint, so that the joint is covered without the compound, creating an unsightly protrusion that extends out between the panels. The installation of the drywall is such that the longitudinal length extends horizontally along a wall parallel to the floor, rather than vertically and substantially perpendicular to the floor, facilitates a faster installation time of the board panels of gypsum, and a faster finishing time of the installed drywall panels. In addition, when the drywall is installed in a vertical orientation, installation and labor costs can be increased, since installers must use ladders for installation and finishing.

When drywall panels are installed on longer walls and ceilings, as the recessed areas only extend along two longitudinal edges of each panel, a butt joint can be formed between the

Side edges of two adjacent panels. These joints should still be covered with a tape and a compound, but since the side edges do not include a recessed area, the joint compound should extend over a wider area than that of the longitudinal joints to facilitate mixing of the butt joints in the wall surface without creating unsightly bumps.

An added difficulty in creating a recessed area at the side edges of the drywall panels is that the panels are made in continuous lengths, which are then cut to size after the drywall panel has completely cured. It is very difficult to create the recessed areas on the drywall panel after the plaster is completely cured, and a particular problem has been the delamination of the paper from the gypsum core. WO 2004/007162 A1 describes a process and a line for the production of hydraulic binder boards having cut ends that are narrowed, the hydraulic binder being, in particular, plaster. The process comprises the steps of i) spraying a softening liquid onto the at least one cut end of the board; ii) wait for the softening liquid to penetrate the board; and iii) applying pressure on said at least one cut end of said hydraulic binder board with multiple presses. The process comprises the steps of moving at least a first and second hydraulic binder boards on a conveyor and applying pressure on the cut ends of said hydraulic binder boards with multiple presses.

Summary of the invention

The present invention comprises a method according to claim 1, as well as a method according to claim 6 and a device according to claim 12.

The dependent claims disclose preferred embodiments.

Brief description of the drawings

Figure 1 is a plan view of a porch having a plurality of drywall presses in accordance with an embodiment of the present invention;

Figure 2 is a perspective view of a dry gypsum board press according to an embodiment of the present invention;

Figure 3 is a perspective view of a top press assembly in accordance with an embodiment of the present invention;

Figure 4 is a perspective view of a lower press assembly according to an embodiment of the present invention;

Figure 5 is a perspective view of a top shoe assembly according to an embodiment of the present invention in an extended position;

Figures 6A-6F are views of a top shoe in accordance with an embodiment of the present invention;

Figure 7 is a perspective view of a top shoe assembly in accordance with an embodiment of the present invention in a retracted position;

Figures 8A-8D are views of a bottom shoe in accordance with an embodiment of the present invention;

Figure 9 is a perspective view of a lower shoe assembly according to an embodiment of the present invention;

Figures 10A-10C are views of a pin according to an embodiment of the present invention;

Figure 11 is a partial side view of a length of gypsum board that passes through an upper and lower press assembly according to an embodiment of the present invention; Y

Figure 12 is a side view of a length of gypsum board that passes through an upper and lower press assembly according to an embodiment of the present invention.

Best way to carry out the invention

Although this invention is capable of realization in many different ways, preferred embodiments of the invention are shown in the drawings and will be described herein in detail with the understanding that the present description should be considered as an exemplification of the scope of the claims and that it is not It is intended to limit the broad aspect of the invention to the illustrated embodiments. With reference to Figure 1, an embodiment of the present invention comprises a press 20 to form one or more recessed lengths of partially cured gypsum board, so that when the partially cured plasterboard is cut into finished lengths, the side edges of the finished lengths have recessed edges on all four edges of the

license plate. For the purposes of the present invention, a recess may be a conical or non-conical recess. The invention preferably performs this press function on partially cured gypsum board panels after the gypsum suspension has been applied to a paper support, but before the drywall is sent to the furnaces for complete curing . However, it is within the scope of the present invention to form recesses along the cured plaster before it is cut into finished lengths.

In this aspect, where the plaster is only partially cured and the uncut plasterboard in the finished lengths, the recessed areas are formed along the side edges of the uncut plasterboard and also in various positions along the length of the boards of uncut plaster. The positions of the recesses in the length of the uncut gypsum boards will vary depending on whether gypsum boards are produced eight feet (2.43 m) in length, nine feet in length, ten feet in length, etc., or combinations of length thereof. Typically, the length of the uncut and partially cured gypsum board that is sent to the furnaces to be completely cured is 9.75 m (32 '), although other lengths can be produced on several plasterboard floors. The length of 9.75 m (32 'feet), or other appropriate length, is indicated as the unfinished length. In the case of lengths of 9.75 m (32 '), it is preferable to have presses located at 0 m (0') (i.e. the side edge), 2.44 m, 2.74 m, 3.05 m , 3.66 m, 4.27 m, 4.88 m, 5.49 m, 6.1 m, 6.71 m, 7.01 m, 7.32 m, 8.23 m (8 ', 9 '10', 12 ', 14', 16 ', 18', 20 ', 22', 23 ', 24', 27 ') and 9.75 m (32') (that is, the opposite side edge). The present invention achieves this by providing presses in each indicated position. Alternatively, a smaller number of presses are provided that can be placed on the support system in different required positions. In addition, the presses are easily removable, so that a press can be removed for repair and maintenance. By feeding the length of 9.75 m (32 ') in the press and forming the recesses at the ends and in one or more positions along the length of the drywall, recesses are formed across the width thereof, such that each common length of the drywall can be manufactured with side edge cones in the lengths of the finished drywall.

The presses 20 each comprise an upper press assembly 22 and a lower press assembly 24. The drywall 26 passes between the upper and lower press assemblies 22 and 24. The upper press assemblies 22 are movable from an upper position. , where the upper press assemblies 22 do not contact the uncut gypsum board and a lower position, where the upper press assemblies 22 come into contact with the uncut gypsum board. Since the recesses are more preferably only about 0.090 "(0.022 m) deep, the upper press assemblies 22 are infinitely adjustable in the vertical direction, such that a fine adjustment can be made to adjust the thickness tolerances of the gypsum board and also to accommodate gypsum boards of different nominal thicknesses The appropriate adjustment of the height of the upper press assembly can be detected both by laser measurement and by physically contacting the gypsum board, for example, with a roller that it measures the precise thickness of the gypsum board.The upper presses 22 are all individually adjustable to adequately control the depth of the recesses, while the gypsum board moves through the presses, as can be seen in Figure 1, four 22 upper press assemblies have been lowered in position at 0 m, 3.66 m, 6.71 m, (0 ', 12', 22 ') and 9.75 m (32') to make a board of y that of 3.05 m (10 ') and 3.66 m (12') long.

Figure 2 shows the upper press assembly 22, the lower press assembly 24 and an extraction conveyor 28 for removing the drywall from the press. An upper surface of the extraction conveyor 28 is preferably in a lower plane than the upper surface of the lower press assembly 24, so that the gypsum board 26 will move away from the upper press assembly 22 as it leaves the assembly of lower press 24. The lengths of drywall 26 are shown between the upper and lower press assemblies 22 and 24, and the press assemblies 22 and 24 and the extraction conveyor 28 move the drywall in a direction indicated by the arrow A.

As shown in Figure 3, the upper press assembly 22 comprises two separate plates 30 and 32 joined together to form an upper plate assembly 34. On the upper plate assembly 34 there is a plurality of upper shoe assemblies 36 The upper shoe assemblies 36 are joined together at their ends and form a loop around the upper plate assembly 34. A large gear wheel 38 is located at a first end 40 of the plate assembly 36, and a small gear wheel 42 it is located at a second opposite end 44 of the plate assembly 36. The sprockets are located between the plates 30 and 32. One or both sprockets 38 and 42 are driven to make the upper shoe assemblies 36 rotate around the assembly of upper plate 34 in the direction indicated by arrows B. A shoe support bar 46 is also provided that holds the upper shoe assemblies 36 adjacent to the assembly of upper plate 34 when the upper shoe assemblies 36 travel along the lower portion of the upper plate assembly 34 until the upper shoe assemblies 36 are out of contact with the drywall when they extend around the wheel Toothed 38 large, as described below.

The lower press assembly 24 is shown in Figure 4 and comprises a first and second plates 48 and 50 joined together and separated from each other to form a lower plate assembly 52 having a first end 56 and a second end 60. Mounted on the lower plate assembly 52 there is a plurality of lower shoe assemblies 54. The lower shoe assemblies 54 extend around the lower plate assembly 52 to form a loop. The lower shoe assemblies 54 are also driven by one or both of a first gear wheel 58 at the first end 56 and a second gear wheel (not shown) at a second end 60.

Referring to Figures 5 and 6A-6F, the upper shoe assemblies 36 of the upper press assembly 22 comprise a forming plate 64. The forming plate 64 comprises two vertical outer walls 66 and 67. Between the walls 66 and 67 two support blocks 68 are located. Each support block 68 defines a hole 70 that is in line with the holes 72 defined in each outer wall 66 and 67. The support blocks 68 also each define an arcuate stop portion 74. Mounted inside holes 70 and 72 is a pin

76. Pin 76 captures three roller bearings 78, as well as two chain side plates 80. Another pin 82 captures three more roller bearings 84 and an opposite end of the chain side plate 80. The pin 82 is associated with the upper shoe assembly 36, thanks to the pin 82 which extends into two grooves 85 that are formed within the side walls 66 and 67 of the forming plate 64. The bearings 84 are separated from each other by collars 75 placed on pin 82 and between bearings 84.

As a result of the pin 82 being located within the grooves 84, the forming plate 64 is allowed to pivotally move around the pin 76 from a first open position, as shown in Figure 6, to a second closed position, as shown in Figure 7, making the distance between the bearing 82 and a lower surface 90 of the forming plate 64 variable.

The upper shoe assembly 36 also comprises a pair of shoe alignment bearings 86 mounted on the support blocks 68. In addition, shoe pivot bearings 88 are attached to each wall 66 and

67. In the most preferred embodiment, the bottom surface 90 of the forming plate 64 is 165.1 mm (6-1 / 2 ") wide, as seen in Figure 6D and Figure 6F. flat pad 92 is centered on the bottom surface 90 of the forming plate 64 approximately 31.75 mm (1-1 / 4 ") wide. First conical portions 94 narrow at an angle of approximately three degrees from the flat pad 92 for approximately 31.75 mm (1-1 / 4 ") from the center of the bottom surface 90. Second conical portions 96 narrow at an angle of approximately one degree from the flat pad 92 from the first conical portion 94 at any edge of the forming plate 64. The plurality of conical surfaces prevent bulging of the drywall at the edge of the forming plate 64.

A plurality of upper shoe assemblies 36 are joined together by the use of additional chain side plates 80 extending from pin 82 to a pin 76 of an adjacent upper drag shoe assembly 36 and a chain side plate 80 extending from a pin 76 of the upper shoe assembly 36 to the pin 82 of an adjacent adjacent upper shoe assembly 36. The forming plates 64 also comprise a front support surface 69 and a rear support surface 71. The point where the support surface 69 meets the bottom surface 90 is located at or behind an imaginary line ZZ which passes to through the center of the holes 70 and 72 aligned and is perpendicular to the surface 90. When the upper shoe assemblies 36 are joined together with the chain side plates 80, the front support surface 69 of an upper shoe assembly 36 it rests on the rear support surface 71 of an upper adjacent shoe assembly 36. Thus, the bottom surfaces 90 of each shoe provide a consistent surface, in which the flat pads 92, the first conical portions 94 and the second conical portions 96 of the attached upper shoe assemblies 36 are aligned and are coplanar to form a consistent surface, even with significant force applied to the surface 90 of each forming plate 64. Referring to Figures 8A-D and 9, the lower shoe assembly 54 comprises a support plate 98. The support plate 98 It has a flat bottom surface 100 and two side walls 102 and 103 extending upward. The support plate 98 also comprises a pair of support blocks 104 which each have aligned holes 106 defined therein which are aligned with the holes 108 defined in the side walls 102 and 103. Inserted into the aligned holes 106 and 108 there is a pin 110. The pin 110 retains three roller bearings 120 and two chain side plates 202 to the support plate 98. Also attached to the two support blocks 104 are alignment bearings 106. The chain side plates 202, each, is fixed to a pin 110 of a previous adjacent support plate 98 and the chain side plates 202 of an adjacent next support plate 98 are fixed to pin 110 of the present support plate 98, and so on , to create a chain. The forming plate 98 also defines an arcuate surface 204 and a rear support platform 206. When several sets of lower shoes 54 are placed, they are joined together by the side chain plates 80, the arched surface 204 of a shoe assembly Lower 54 rests on the rear support platform 206 of an adjacent lower shoe assembly 54. As a result, the lower surfaces 100 of the lower shoe assemblies 54 form a flat surface, on which a partially cured gypsum board sheet 26 can rest without deformation of the gypsum board 26.

Referring to Figures 10 A-C, pins 76, 82 and 110 are preferably identical and are described with respect to representative pin 76. The pin 76 has a central hole 130 that is threaded at both ends. The pin 76 also has annular grooves 132 in the positions corresponding to the mounting of the bearings thereon. Connecting holes 134 extend through pin 76 in the position of the annular grooves 132 to provide a path from the annular grooves 132 to the central hole 130. In this manner, greased pins can be screwed into the pin 76 in the hole. center 130 to provide grease through the central hole 130 to the connection holes 134 in the annular grooves 132 and to lubricate the bearings mounted on the pin 76. The annular grooves 136 are sized to accept retaining clips to retain the pins 76 in the forming plate 64 or the support plate 98, as the case may be.

The upper shoe assemblies 36 of the upper press assembly 22 are maintained and aligned on the plates 30 and 32 by the shoe alignment bearings 86. The shoe alignment bearings 86 contact the inner surfaces 120 and 122 of the plates 30 and 32, respectively, of the upper press assembly 22. Also, the lower shoe assemblies 54 of the lower press assembly 24 are maintained and aligned on the plates 48 and 50 by the alignment bearings 106. The alignment bearings 106 they contact the inner surfaces 124 and 128 of the plates 48 and 50 of the lower press assembly 24.

Figure 12 shows a simplified view of the interaction of the upper shoe assemblies 36 and the lower shoes 54 as they move around the perimeter of the plates 30 and 32 and the plates 48 and 50, respectively. The upper shoe assemblies 36, as they pass around the second end 44 of the upper press assembly 22, pivot outward. In this manner, the surfaces 90 of the upper shoe assemblies 36 become parallel to the drywall 26 at the point where the surfaces 90 first make contact with the drywall. The upper shoe assemblies 36 initially make contact with the gypsum board 26 and compress it in an initial 0.254 mm (0.010 "). Thus, the upper shoe assemblies 36 do not deepen or cause damage to the drywall 26 with a leading edge of the upper shoe assembly 36.

The lower shoe assemblies 54, when they pass around the second end 41 of the lower press assembly 24, as seen in Figure 12, are placed in parallel relationship with the drywall 26 and contact the drywall 26 before that the upper shoe assemblies 36 contact the gypsum board 26. In this way, the lower shoe assemblies 54 provide support for the gypsum board 26 and an opposite force for the upper shoe assembly 36 when it makes initial contact with the gypsum board 26 and compression of the gypsum board 26 begins. Additionally, to prevent a lower shoe assembly 54 above, with the label M in Figure 12, being forced into the gypsum board 26 by the support surface 204 (if the support surface were not arched) a rear lower shoe assembly 54, with the label of N in Figure 12, the support surface 204 is made arched so that the center of the arc or formed by the surface 204 is the center of the hole 108.

Referring to Figure 12, when the gypsum board 26 crosses from right to left, the upper shoe assemblies 36 move from an initial print of 0.254 mm (0.010 ") near an X point to a final print of 0.259 mm (0.0102 ") near a point Y with the horizontal length between points X and Y which is preferably approximately 1.7 m (67"). This is achieved by a taper along the bottom plates 30 and 32 that force the upper shoe assemblies 36 on the gypsum board thanks to the contact with the bearings 78 and 84. After point Y, the plates 30 and 32 provide a taper that takes the upper shoes 36 out of contact with the gypsum board 26. An extraction conveyor 28 removes the gypsum board 26 from the press 20. In a further preferred aspect of the invention, the side edges of the finished lengths of the gypsum board are wrapped with paper to further reinforce the edge e of the drywall.

Although specific embodiments have been illustrated and described, numerous modifications come to mind without significantly departing from the scope of the appended claims.

Claims (17)

1. A process for the manufacture of gypsum boards (26), comprising:

(to)

 providing an unfinished length of gypsum board (26) that has a recess along its longitudinal edges transporting it on a conveyor in a first direction;

(b)

 forming a plurality of recesses on a first surface of the gypsum board (26) by the step of gradually compressing the gypsum board (26), a lateral recess on each side edge of the unfinished length and at least one recess between, parallel to, and displaced from, the side edges when the gypsum board (26) is transported in said direction generally parallel to the recess; Y

(C)

 cut the unfinished length of the drywall (26) in the at least one offset side offset to form a plurality of finished lengths of drywall (26), such that each finished length of drywall (26) has lowered edges along the four edges of the first surface.

2.

 Method according to claim 1, which also comprises the step of selecting an apparatus for forming the recess from a plurality of devices for forming the recess and placing the recess forming apparatus in the desired position of the recesses.

3.

 Method according to claim 2, wherein the step of selecting an apparatus to form the recess from a plurality of apparatus to form the recess also comprises the step of lowering the recess forming apparatus to contact the gypsum board (26 ) in the desired position of the recess.

Four.

 Method according to claims 2 or 3, wherein the apparatus is capable of forming a plurality of recesses at the same time.

5.

 Method according to any one of claims 1 to 4, wherein a plurality of lengths of finished gypsum board (26) are produced from a single unfinished length of gypsum board (26).

6.

 Procedure for the manufacture of gypsum boards (26), which includes:

(to)

 provide an unfinished length of gypsum board that has a recess along its longitudinal edges transporting it on a conveyor in a first direction;

(b)

 forming a plurality of recesses on a first surface of the gypsum board (26), a lateral recess forming on each side edge of the gypsum board (26) and at least one recess forming between, parallel to and offset from, the side edges, forming said recesses transporting the unfinished length of gypsum board (26) through a recess forming apparatus having a plurality of presses, at least one placed on each side edge of the gypsum board (26) and at least one Position between, parallel to and displaced from, the presses corresponding to the side edges of the drywall (26), each press having an upper and lower press assembly (22, 24):

(i)

 wherein the upper assembly comprises an infinite loop that has an outer surface that can rotate around the upper press assembly (22) and the lower press assembly (24) comprises an infinite loop that has a rotating outer surface around the lower assembly ,

(ii)

 in which the upper and lower press assemblies (22, 24) are placed opposite each other,

(iii) in which a gap between the outer surfaces of the loops of the upper and lower press assemblies (22, 24) gradually narrows from a first distance at a first end of the press assembly (22) to a second distance closest; the presses being placed in such a way that they will be coupled with a leading longitudinal edge of the unfinished length of the drywall (26) when the unfinished length enters the recess and the conicity of the recess will cause a gradual compression of the unfinished length when the unfinished length passes through the gap.

7.

 Method according to claim 6, which also comprises the step of cutting the unfinished length of the gypsum board (26) in the at least one offset offset to form a plurality of finished lengths of gypsum board (26), such that Each finished length of drywall (26) has lowered edges along the four edges of the first surface.

8.

 Method according to any of claims 6 or 7, wherein the upper assembly is movable from a first position removed from the gypsum board (26) and a second position in contact with the gypsum board (26), and wherein the The method also includes the step of selecting and moving to the second position those upper assemblies necessary to produce the recesses in the desired positions.

9.

 Method according to any of claims 6 to 8, wherein the number of recesses to be formed is three, one on each side edge and one in a position between, displaced from and parallel to, the side edges.

10.

 Method according to any of claims 6 to 9, wherein the recess forming apparatus has the

minus three of stationary presses, two placed in the apparatus to correspond to each side edge of the gypsum board 5 (26) and a plurality of presses placed to correspond to the various lengths of gypsum boards (26) to produce. A method according to any one of claims 6 to 9, wherein the recess forming apparatus has at least three positionable presses, two capable of being placed in the apparatus to correspond to each of the side edges of the drywall ( 26) and a plurality of presses capable of being placed to correspond to 10 the different lengths of gypsum boards (26) to be produced, and in which the process also comprises the step of placing the presses, or that number of presses necessary, in the positions corresponding to the positions of the desired recesses in the board plaster (26). 12. A device for forming recesses in an unfinished length of gypsum board (26), said said comprising device a plurality of presses in a separate parallel relationship, each comprising upper and lower press assemblies 15:

(to)

 wherein the upper assembly comprises an infinite loop having a rotating outer surface around the upper press assembly (22), and the lower press assembly (24) comprises an infinite loop having a rotating outer surface around the lower assembly,

(b)

in which the upper and lower press assemblies (22, 24) are placed opposite each other,

20 (c) in which a gap between the outer surfaces of the loops of the upper and lower press assemblies gradually narrows from a first distance at a first end of the press assembly to a second closer distance, and (d) in which, in use, at least three presses, corresponding to two lateral recesses along the side edges of a length of gypsum board (26), plus a plurality of recesses that are formed 25 generally parallel and displaced from said lateral edges, are positioned such that they will be coupled with a leading longitudinal edge of an unfinished length of drywall (26) when the unfinished length enters the recess and the conicity of the recess will cause a gradual compression of the unfinished length when the unfinished length passes through the gap. 13. Device according to claim 12, comprising three sets of presses. 14. Device according to claim 12 or 13, wherein the separation of the presses is fixed. 15. Device according to claim 12 or 13, wherein at least one press can be placed on the support system in the various required positions so that the recess to be formed by said at least one press can be formed in, and is perpendicular a, any desired position along the longitudinal edge of the gypsum board (26). Device according to claim 12 or 13, in which all presses can be placed on the support system in the various required positions. 17. Device according to any of claims 12 to 16, wherein each upper assembly is movable from a first position where it is removed from the point where it will be coupled to an unfinished length of gypsum board (26) in the recess to a second position where you will be in contact with and will be able to form a recess of the Desired depth on an upper surface of a length of gypsum board (26) that passes through the gap.

18.

 Device according to any of claims 12 to 17, wherein the length of the gap is at least 0.15 meters.

19.

 Device according to any of claims 12 to 18, which also comprises means for contacting

45 physically with the gypsum board, to detect changes in the thickness of the gypsum board (26) to be processed and adjusting the position of the upper assembly to ensure a consistent depth of the recess.