Gypsum board manufacturing device and gypsum board manufacturing method

Abstract

Provided is a gypsum board manufacturing device for manufacturing a gypsum board in which at least an upper surface and a lower surface of a gypsum core are covered by a coating material, said manufacturing device including: a conveyance device for conveying the coating material; a mixer for preparing a gypsum slurry containing calcined gypsum and water, and supplying the gypsum slurry onto the coating material; a pressing device that has a pressing member for pressing the coating material conveyed by the conveyance device to the conveyance device, and a drive device for changing the distance between the pressing member and the coating material; and a control device that controls the drive device to change the distance between the pressing member and the coating material so as to switch between a pressing state in which the pressing member is pressing the coating material against the conveyance device and a release state in which the pressing member is separated from the coating material. The control device is set to the pressing state when the conveyance device starts conveyance of the coating material, and thereafter switches from the pressing state to the release state.

Description

Gypsum board manufacturing equipment, gypsum board manufacturing method

[0001] The present invention relates to a gypsum board manufacturing apparatus and a gypsum board manufacturing method.

[0002] Patent Document 1 discloses a method for manufacturing a gypsum board, which comprises feeding a roll of gypsum board surface base paper onto the upper surface of an endless belt conveyor, continuously dropping a dry gypsum paste from a first mixer onto the upper surface of the fed surface base paper, smoothing the dropped dry gypsum paste with a first roller, continuously dropping lightweight aerated gypsum from a second mixer onto the upper surface of the smoothed dry gypsum paste and smoothing it with a second roller, continuously dropping dry gypsum paste from a third mixer onto the upper surface of the smoothed lightweight aerated gypsum paste and smoothing it with a third roller, and while this is being done, a roll of gypsum board surface base paper provided separately from the above is wound around the third roller and adhered to the upper surface of the smoothed dry gypsum paste, and then the paper is sent to a cutting process, cut to an appropriate width, and further dried.

[0003] Japanese Patent Publication No. 52-144028

[0004] A gypsum board having a covering material disposed on its surface is manufactured by supplying a gypsum slurry so that it is positioned between the conveyed covering materials, and then molding and hardening the gypsum slurry.

[0005] Therefore, when the production of gypsum boards begins, the conveyance of the covering material is started, followed by the production and supply of the gypsum slurry. However, because the covering material is made of paper, nonwoven fabric, etc. and is lightweight, it has been difficult to stably convey only the covering material before the supply of the gypsum slurry begins.

[0006] Therefore, one aspect of the present invention aims to provide a gypsum board manufacturing apparatus that can transport a coating material using a transport device even before the gypsum slurry is supplied.

[0007] In order to solve the above problems, according to one aspect of the present invention, there is provided a gypsum board manufacturing apparatus for manufacturing gypsum boards in which at least the upper and lower surfaces of a gypsum core are covered with a coating material, the gypsum board manufacturing apparatus comprising: a conveying device for conveying the coating material; a mixer for preparing a gypsum slurry containing calcined gypsum and water and supplying the gypsum slurry onto the coating material; a pressing device having a pressing member for pressing the coating material being conveyed by the conveying device against the conveying device and a drive device for changing the distance between the pressing member and the coating material; and a control device for controlling the drive device to change the distance between the pressing member and the coating material, and for switching between a pressed state in which the pressing member presses the coating material against the conveying device and an open state in which the pressing member is separated from the coating material, wherein the control device switches the gypsum board manufacturing apparatus to the pressed state when the conveying device starts conveying the coating material, and then switches from the pressed state to the open state.

[0008] According to one aspect of the present invention, it is possible to provide a gypsum board manufacturing apparatus that can transport a coating material by a transport device even before a gypsum slurry is supplied.

[0009] FIG. 1A is an explanatory diagram of a gypsum board manufacturing apparatus according to one embodiment of the present invention. FIG. 1B is an explanatory diagram of a gypsum board manufacturing apparatus according to one embodiment of the present invention. FIG. 1C is an explanatory diagram of a gypsum board manufacturing apparatus according to one embodiment of the present invention. FIG. 1D is an explanatory diagram of a gypsum board manufacturing apparatus according to one embodiment of the present invention. FIG. 2A is an explanatory diagram of an example configuration of a pressing device. FIG. 2B is an explanatory diagram of an example configuration of a pressing device. FIG. 2C is an explanatory diagram of an example configuration of a pressing device. FIG. 3 is an explanatory diagram of the arrangement of a pressing device in a gypsum board manufacturing apparatus according to one embodiment of the present invention.

[0010] Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings, but the present invention is not limited to the following embodiments, and various modifications and substitutions can be made to the following embodiments without departing from the scope of the present invention. [Gypsum Board Manufacturing Apparatus] Hereinafter, a gypsum board manufacturing apparatus according to one embodiment of the present disclosure (hereinafter referred to as "embodiment") will be described with reference to the drawings.

[0011] It should be noted that all of the drawings are schematic diagrams for explaining the configuration of the gypsum board manufacturing apparatus of this embodiment, and do not accurately depict the sizes, etc. (1) Regarding gypsum boards There are no particular limitations on the types of gypsum boards manufactured by the gypsum board manufacturing apparatus of this embodiment or the gypsum board manufacturing method described below.

[0012] The gypsum board manufactured by the gypsum board manufacturing apparatus of the present embodiment may be a gypsum board in which at least the upper and lower surfaces of the gypsum core are covered with a covering material. Note that "at least the upper and lower surfaces of the gypsum core are covered with a covering material" also includes cases in which the covering material is embedded near the upper and lower surfaces of the gypsum core. Therefore, a gypsum board in which at least the upper and lower surfaces of the gypsum core are covered with a covering material can also be referred to as a gypsum board in which a covering material is disposed on at least the upper and lower surfaces of the gypsum core.

[0013] The gypsum board may be any one selected from, for example, glass mat gypsum board, gypsum-containing board with glass fiber nonwoven fabric, gypsum board specified in JIS A 6901 (2014), gypsum board that is lighter or heavier than the gypsum board specified in JIS A 6901 (2014) (hereinafter, the gypsum board specified in JIS and the gypsum board that is lighter or heavier than the gypsum board specified in JIS are also collectively referred to as "gypsum board").

[0014] The glass mat gypsum board is, for example, a gypsum board in which at least the upper and lower surfaces of a gypsum core are covered with a glass mat as a covering material.

[0015] The gypsum-containing board with nonwoven glass fiber fabric is, for example, a gypsum board in which nonwoven glass fiber fabric (glass tissue) as a covering material is embedded near at least the upper and lower surfaces of the gypsum core.

[0016] The gypsum board is, for example, a gypsum board in which at least the upper and lower surfaces of a gypsum core are covered with a covering material, gypsum board base paper.

[0017] In addition, depending on the type of the gypsum board, at least a portion of the side surface of the gypsum core of the gypsum board may also be covered with a covering material. (2) Configuration of the Gypsum Board Manufacturing Apparatus Hereinafter, the configuration of the apparatus will be described using Figures 1A to 1D as an example of a configuration of the gypsum board manufacturing apparatus of this embodiment, taking the case of manufacturing a gypsum board as an example.

[0018] 1A to 1D are explanatory diagrams of the gypsum board manufacturing apparatus of this embodiment, with Fig. 1A showing the state immediately after the start of operation of the gypsum board manufacturing apparatus, when only the conveyance of the covering material 11 has begun. Fig. 1B and Fig. 1C show the change over time immediately after the start of supplying the gypsum slurry. Fig. 1D shows the state during normal gypsum board manufacturing, showing the state in which gypsum boards are steadily manufactured.

[0019] As shown in FIGS. 1A to 1D, the gypsum board manufacturing apparatus 10 of this embodiment includes a conveying device 21, a mixer 12, a pressing device 20, and a control device 18. A specific configuration example of a gypsum board manufacturing apparatus is described below. In FIGS. 1A to 1D and 2A to 2C, the X axis is the axis along the conveyance direction of the covering material 11, the Y axis is the axis along the width of the covering material 11, and the Z axis is the axis along the height. (2-1) Mixer The mixer 12 can prepare a gypsum slurry containing calcined gypsum and water and supply the gypsum slurry onto the covering material. For this reason, the mixer 12 can be disposed at a predetermined position related to the conveyance path of the covering material 11, such as the first gypsum board base paper 111 and the second gypsum board base paper 112, for example, above or to the side of the conveyance path. Then, in the mixer 12, calcined gypsum, which is a raw material for the gypsum slurry, water, and, in some cases, various additives and foams are kneaded together to prepare the gypsum slurry.

[0020] Here, calcined gypsum is also known as calcium sulfate hemihydrate and is an inorganic composition having hydraulic properties. As the calcined gypsum, β-type calcined gypsum or α-type calcined gypsum alone, or a mixture of the two, can be used. β-type calcined gypsum is obtained by calcining in the atmosphere any one of natural gypsum, by-product gypsum, flue gas desulfurization gypsum, recycled gypsum such as waste gypsum board, etc., alone, or a mixture of any of these. α-type calcined gypsum is obtained by calcining in water (including in steam) any one of natural gypsum, by-product gypsum, flue gas desulfurization gypsum, recycled gypsum such as waste gypsum board, etc., alone, or a mixture of any of these.

[0021] When producing a gypsum board, the calcined gypsum used as a raw material preferably contains β-type calcined gypsum, and it is more preferable that the main component of the calcined gypsum used as a raw material for the gypsum board is β-type calcined gypsum. Note that, when the main component of the calcined gypsum used as a raw material for the gypsum board is β-type calcined gypsum, this means that the β-type calcined gypsum accounts for more than 50% by mass of the calcined gypsum used as a raw material for the gypsum board. When producing a gypsum board, the calcined gypsum used as a raw material may be composed only of β-type calcined gypsum.

[0022] To produce α-type calcined gypsum, it is necessary to calcinate dihydrate gypsum such as natural gypsum under pressure in water or steam using an autoclave. In contrast, β-type calcined gypsum can be produced by calcining dihydrate gypsum such as natural gypsum in the atmosphere at normal pressure, and β-type calcined gypsum can be produced more productively than α-type calcined gypsum.

[0023] Examples of additives include one or more selected from adhesion improvers such as starch and polyvinyl alcohol, inorganic fibers such as glass fibers, lightweight aggregates, fire-resistant materials such as vermiculite, setting retarders, setting accelerators, water-reducing agents, foaming agents such as sodium alkyl sulfate, alkyl ether sulfates, sodium alkylbenzene sulfonates, and polyoxyethylene alkyl sulfates, bubble size adjusters such as sulfosuccinate surfactants, water repellents such as silicone and paraffin, organic carboxylic acids, and organic carboxylates.

[0024] The adhesion improver is an additive that improves the adhesion between a gypsum hardened body (a product of hardening a gypsum slurry) and a covering material such as base paper for gypsum boards.

[0025] The calcined gypsum and some of the additives, for example, solid additives, may be mixed and stirred in advance to form a gypsum composition, which is a mixture, and then supplied to the mixer 12 .

[0026] Furthermore, foam can be added at gypsum slurry dispensing port 121 and the amount of foam added can be adjusted to produce a gypsum slurry of any density.

[0027] The first gypsum board base paper 111 is folded so that both side edges thereof extend upward and then inward along the score lines just before the forming device 16, enveloping the gypsum slurry. The second gypsum board base paper 112 is diverted, for example, by diverting rolls 15, toward the conveying line of the first gypsum board base paper 111, and is sent to the forming device 16 without being folded.

[0028] 1B to 1D, the gypsum slurry 14 supplied from the mixer 12 is supplied onto the first gypsum board base paper 111, and the second gypsum board base paper 112 is placed on top of the gypsum slurry 14 immediately before the forming device 16. Therefore, it can also be said that the mixer 12 supplies the gypsum slurry between the two covering materials 11. (2-2) Conveying Device The conveying device 21 can convey the covering material 11. In FIGS. 1A to 1D, the conveying device 21 is shown only in a portion of the conveying path of the first gypsum board base paper 111 and the second gypsum board base paper 112, which are the covering materials, but the conveying device 21 can also be placed in other portions of the conveying path of the covering material 11.

[0029] 1A to 1D , the conveying device 21 is exemplified by a belt conveyor in which a belt 212 is hung between a pair of pulleys 211 and a roll 213 that supports a coating material or the like is disposed between the pair of pulleys 211. However, the conveying device 21 may be any device that can support and convey the coating material 11 and the gypsum slurry molded body 17, and is not limited to the above form.

[0030] The conveying device 21 may be one or more types selected from, for example, a belt conveyor, a roll conveyor, etc. The conveying device 21 may include multiple types of conveying devices, such as a belt conveyor and a roll conveyor. (2-3) Pressing Device (2-3-1) Configuration of Pressing Device As shown in FIG. 1D , after a sufficient amount of gypsum slurry 14 is supplied from the mixer 12, the gypsum slurry 14 is disposed between the first gypsum board base paper 111 and the second gypsum board base paper 112, which are the covering material 11, and forms a gypsum slurry molded body 17 having sufficient weight. Therefore, the conveying device 21, which is located downstream of the molding device 16, can easily transport the gypsum slurry molded body 17.

[0031] However, as shown in Fig. 1A , for example, at the start of gypsum board production, two covering materials 11, namely, first gypsum board base paper 111 and second gypsum board base paper 112, are stacked and transported by a transport device 21 downstream of the forming device 16. Because the two covering materials 11 are lightweight, sufficient frictional force is not generated between them and the transport device 21, and the force of the transport device 21 is not sufficiently transmitted to the covering material 11. Even when the transport device 21 is operated, slip occurs between the transport device 21 and the covering material 11, making it impossible to transport the covering material 11. Furthermore, immediately after the start of supply of the gypsum slurry 14 as shown in Figs. 1B and 1C , the transport device 21 alone may not be able to transport the covering material 11 or the gypsum slurry molded body 17 until the area to which the gypsum slurry 14 is supplied becomes long enough and the gypsum slurry molded body 17 becomes heavy enough.

[0032] Therefore, the gypsum board manufacturing apparatus of this embodiment can have a pressing device 20.

[0033] The pressing device 20, like the pressing device 20A shown in FIGS. 1A to 1D and 2A, has a pressing member 201 and a driving device 202 that changes the distance between the pressing member 201 and the covering material 11.

[0034] The pressing member 201 can contact one or more members selected from the first gypsum board base paper 111 and the second gypsum board base paper 112, which are the covering material 11 being transported by the transport device 21, and press the covering material 11 against the transport device 21. (Pressing Member) The pressing member 201 of the pressing device 20 is not particularly limited as long as it is a member that, when pressed against the covering material 11, does not hinder the transport of the covering material 11 and can press the covering material 11 against the transport device 21. The pressing member 201 of the pressing device 20 is preferably a member that can rotate as the covering material 11 is transported, as shown in, for example, Figures 1A to 1D and 2A. For this reason, the pressing member 201 preferably has a circular cross-sectional shape in the XZ plane perpendicular to the Y axis, that is, a plane perpendicular to the top surface of the covering material 11 and along the transport direction of the covering material 11. The top surface of the covering material 11 refers to the surface that the pressing member 201 contacts. The cross-sectional shape of the pressing member 201 refers to the outer shape of the pressing member 201. Examples of the pressing member 201 include various types of rolls and tires.

[0035] When the pressing member 201 is a tire, and when the tire is a pneumatic tire, it is preferable that the magnitude of the force with which the pressing member 201 presses the covering material 11 against the conveying device 21 can be easily adjusted depending on the amount of air filled inside, the pressure, etc.

[0036] When the pressing member 201 is a tire, the air pressure of the tire is preferably 0.01 MPa or more and 0.5 MPa or less.

[0037] 2A , it is preferable that a roll 213A of the conveying device 21 is disposed below the point where the pressing member 201 of the pressing device 20 contacts the coating material 11. That is, it is preferable that the roll 213A is disposed so that the pressing member 201 and the roll 213A can sandwich the coating material 11. It is preferable that the roll 213A disposed below the point where the pressing member 201 of the pressing device 20 contacts the coating material 11 has a larger outer diameter than the other rolls 213, so that it can support the load applied by the pressing device 20 via the coating material 11.

[0038] Instead of the roll 213A, the conveying device 21 may have a roll 213B positioned upstream or downstream along the conveying direction of the coating material 11 from below the point where the pressing member 201 of the pressing device 20 contacts the coating material 11. By having the roll 213B in the conveying device 21, when the pressing device 20 presses the coating material 11 against the conveying device 21, the belt 212 sinks, thereby improving the adhesion between the coating material 11 and the conveying device 21. The roll 213B may also have a different outer diameter from the other rolls 213. (Driver) The driver 202 may be a device that can change the distance L (see FIG. 1D ) between the pressing member 201 and the coating material 11 and press the pressing member 201 against the coating material 11 or move the pressing member 201 away from the coating material 11, as shown in FIGS. 1A to 1D .

[0039] The driving device 202 may include, for example, an air cylinder or an oil cylinder (hydraulic cylinder).

[0040] 1A to 1D, and along the double-headed arrow A in Fig. 2A. When the driving device 202 is an air cylinder or the like, the driving device 202 is configured to place the driving device 201 on a rod 2021 of the driving device 202 as shown in Fig. 2A. By extending and contracting the rod 2021 along the double-headed arrow A, the distance between the driving device 201 and the covering material 11 can be changed.

[0041] 2A shows an example in which the pressing member 201 is disposed directly on the rod 2021, but the present invention is not limited to this configuration, and the rod 2021 and the pressing member 201 can also be configured to be connected via various frames. Also, if necessary, a damper or the like that absorbs impact can be disposed between the pressing member 201 and the rod 2021. (Other Configuration Examples of Pressing Device) The pressing device 20 is not limited to the configuration of the pressing device 20A shown in FIGS. 1A to 1D and 2A.

[0042] For example, like a pressing device 20B shown in FIG. 2B, the pressing device 20 may have a frame 203 in addition to a pressing member 201 and a driving device 202.

[0043] The shape of the frame 203 is not particularly limited, but may be, for example, a rod-like or plate-like body, and the pressing member 201 may be installed at a first end 2031 of the frame 203. Furthermore, a fulcrum 203A may be provided at a second end 2032 of the frame 203, which serves as the center of rotation when a force is applied to the frame 203 by the driving device 202. The fulcrum 203A may be formed, for example, by fixing the frame 203 to a support 204 so that the frame 203 can rotate around the fulcrum 203A.

[0044] At any position on the frame 203, the driving device 202 can apply a force to the frame 203 to move it upward or downward as indicated by the double-headed arrow B. At a point of application 203B where the driving device 202 applies a force to the frame 203, the rod 2021 of the driving device 202 can be connected to the frame 203 so as not to impede the movement of the frame 203 when the force is applied to the frame 203.

[0045] With the above configuration, when drive device 202 applies a force to frame 203 in the upward or downward direction indicated by double-headed arrow B, frame 203 can rotate as indicated by double-headed arrow C, with fulcrum 203A provided at second end 2032 as the center of rotation. Therefore, the distance between pressing member 201 and covering material 11 can be configured to be changeable.

[0046] By rotating the frame 203, for example, around a fulcrum 203A provided at the second end 2032 of the frame 203, and displacing the position of the pressing member 201 provided at the first end 2031 of the frame 203, it becomes easier to control the impact when the pressing member 201 comes into contact with the coating material 11. This makes it possible to prevent damage to the coating material 11 and to stably transport the coating material 11. (Resistance Adding Device) The pressing device 20 may further include any optional components.

[0047] The pressing device 20 may also have a resistance adding device 205 that applies a force in a direction in which the pressing member 201 moves away from the covering material 11, as in the pressing device 20C shown in FIG. 2C.

[0048] The configuration of the resistance adding device 205 is not particularly limited, but may include, for example, a weight 2051, a connecting member 2052 such as a string, rope, chain, or wire that connects the weight 2051 to the frame 203, and a pulley 2053 that adjusts the direction of the force applied to the frame 203. By connecting the weight 2051 and the frame 203 to both ends of the connecting member 2052 and hanging it on the pulley 2053, it is possible to apply a force upward to the frame 203 as shown by arrow D.

[0049] The configuration of the resistance adding device 205 is not limited to the example of Figure 2C, and it can also be configured, for example, such that one end of an elastic member such as a spring is connected near the first end 2031 of the frame 203, and the other end is connected to a support member positioned above the frame 203.

[0050] By providing the resistance adding device 205, unless the driving device 202 applies a force equal to or greater than a certain level, the pressing member 201 cannot approach the covering material 11. This prevents the pressing member 201 from unexpectedly approaching and coming into contact with the covering material 11 due to a malfunction of the driving device 202 or the like.

[0051] 2A , the resistance adding device 205 can be provided to the pressing device 20A, and in this case, the resistance adding device 205 can be installed, for example, relative to the rod 2021. (2-3-2) Arrangement of Pressing Device The arrangement of the pressing device 20 is not particularly limited, and the pressing device 20 can be installed in a location where frictional force can be applied between the coating material 11 and the conveying device 21 so that the coating material 11 can be conveyed by the conveying device 21 even before the gypsum slurry is supplied, and in a number of units that can apply the frictional force required for conveying the coating material 11.

[0052] It is preferable to arrange the pressing devices 20 in an appropriate number at appropriate positions relative to the production line so that the covering material 11 can be transported by the conveying device 21, depending on the length and layout of the production line of the gypsum board manufacturing apparatus 10, the production speed, the weight of the gypsum slurry 14 placed on the covering material 11, etc.

[0053] For example, multiple pressing devices 20 can be arranged along the width of the coating material 11 transported by the transport device 21, i.e., along the Y axis, such as pressing device 20a and pressing device 20b, or pressing device 20c and pressing device 20d shown in Figure 3.

[0054] By arranging multiple pressing devices 20 along the width of the coating material 11, the difference in the magnitude of friction force between the coating material 11 and the conveying device 21 depending on the widthwise position of the coating material 11 can be reduced, and the coating material 11 can be prevented from meandering, etc.

[0055] The pressing device 20 can be fixed to support members 301, 302, etc., arranged along the width of the covering material 11, as shown in FIG.

[0056] FIG. 3 shows an example in which two pressing devices 20 (20a, 20b, or 20c, 20d) are arranged along the width of the covering material 11, but the present invention is not limited to this configuration, and one or three or more pressing devices may be arranged.

[0057] 1A to 1D, and like pressing devices 20a to 20d shown in Fig. 3, a plurality of pressing devices 20 can be arranged along the conveying direction of the coating material 11 in the conveying device 21, that is, along the X-axis in Figs. 1A to 1D and 3. The coating material 11 is conveyed in the direction of the block arrow in Fig. 3.

[0058] By installing a plurality of pressing devices 20 along the conveying direction of the covering material 11, the covering material 11 can be easily transported along the entire conveying path along which the covering material 11 is transported when manufacturing a gypsum board.

[0059] Although the area in which the pressing device 20 is disposed is not particularly limited, it is preferable to dispose it between the molding device 16 and the rough cutting device 22, which will be described later. Cutting of the gypsum slurry molded body 17 is usually performed after the hardening of the gypsum slurry has progressed sufficiently. For this reason, the distance between the molding device 16 and the rough cutting device 22 is selected so that the hardening of the gypsum slurry 14 contained in the gypsum slurry molded body 17 being transported progresses sufficiently. Therefore, by installing the pressing device 20 in the above section, the coating material 11 can be easily transported and placed over the entire transport path of the coating material 11 in the gypsum board manufacturing apparatus 10, even before the gypsum slurry is supplied, which is preferable.

[0060] In particular, the pressing device 20 is preferably disposed between the molding device 16 and point 23 in FIGS. 1A to 1D.

[0061] The point 23 is a point away from the forming device 16 by half the distance L1 between the forming device 16 and the rough cutting device 22. That is, the distance L2 between the forming device 16 and the point 23 satisfies the relationship L2 = L1 ÷ 2.

[0062] The distance L1 refers to the distance from the exit of the forming device 16 to the point where the coating material 11 is cut by the rough cutting device 22. The distance L2 refers to the distance from the exit of the forming device 16 to the point 23. The position of the pressing device 20 refers to the position where the pressing member 201 of the pressing device 20 comes into contact with the coating material 11.

[0063] As shown in Fig. 1A, when starting the production of gypsum boards, conveyance of the covering material 11 is started. At this time, as shown in Fig. 1A, only the covering material 11 is conveyed, and gypsum slurry or the like is not supplied.

[0064] Next, the supply of only water to the mixer 12 is started. At this time, the point on the coating material 11 where only water is first supplied is defined as a water supply start point 11A (see FIGS. 1B and 1C).

[0065] Thereafter, the supply of raw materials for the gypsum slurry, such as calcined gypsum, to the mixer 12 and kneading are started.

[0066] 1B and 1C, supply of gypsum slurry 14 onto the covering material 11 is started. At this time, a point on the covering material 11 where the gypsum slurry 14 is first supplied is defined as a slurry supply start point 11B. As time passes after the supply of the gypsum slurry 14 is started, the region downstream of the molding device 16 where the gypsum slurry 14 is supplied, i.e., the region that has become a gypsum slurry molded body 17, becomes longer as shown in FIGS. 1B to 1D.

[0067] When the region that forms the gypsum slurry formed body 17 becomes longer, the force acting on the coating material 11 downstream of the forming device 16 to transport the coating material 11 in the transport direction becomes greater than the sum of the forces acting on the coating material 11 upstream of the forming device 16 that hinder the transport of the coating material 11.

[0068] Therefore, even if the pressing by the pressing device 20 is released, the coating material 11 and the gypsum slurry molded body 17 can be transported by the transport device 21. In other words, even if the pressing device 20 does not press the coating material 11 against the transport device 21, the coating material 11 can be transported by the transport device 21.

[0069] Forces acting on the coating material 11 upstream of the forming device 16 that hinder the transport of the coating material 11 include tension applied to the coating material 11 along the transport path, reaction forces from the rolls around which the coating material 11 is wound, and frictional forces between the coating material 11 and processing devices that bend the coating material 11 or parts that come into contact with the coating material 11 along the transport path.

[0070] An example of the force acting on the coating material 11 downstream of the forming device 16 to transport the coating material 11 in the transport direction is the force that transports the coating material 11 and the gypsum slurry molded body 17 transmitted from the transport device 21. Note that if the supply of the gypsum slurry 14 is insufficient and the coating material 11 and the gypsum slurry molded body 17 are not sufficiently heavy, a sufficient frictional force is not applied between the transport device 21 and the coating material 11, and the force cannot be sufficiently transmitted from the transport device 21 to the coating material 11, etc.

[0071] According to the investigations of the inventors of the present invention, if the pressing device 20 is arranged between the outlet of the molding device 16 and the above-mentioned point 23, the coating material 11 can be transported by the transport device 21 even before the gypsum slurry 14 is supplied.

[0072] When the gypsum board manufacturing apparatus 10 of this embodiment has multiple pressing devices 20, it is preferable that all of the pressing devices 20 are arranged between the forming device 16 and the rough cutting device 22, and it is more preferable that they are arranged between the forming device 16 and the point 23.

[0073] The molding device 16 and the rough cutting device 22 will be described later, but they can be arranged in sequence along the conveying direction of the coating material 11 downstream of the point 141 in the conveying device 21 where the gypsum slurry is supplied from the mixer 12 onto the coating material 11.

[0074] As described below, the molding device 16 can mold the coating material 11 and the gypsum slurry 14 into a molded gypsum slurry body 17.

[0075] The rough cutting device 22 can roughly cut the gypsum slurry molded body 17. The rough cutting device 22 is a device that cuts the gypsum slurry molded body 17, and therefore can also be called a cutting device. A plurality of cutting devices may be installed in the gypsum board manufacturing apparatus 10, and the rough cutting device 22 refers to the cutting device for the gypsum slurry molded body 17 that is arranged at the most upstream of the plurality of cutting devices along the conveying direction of the gypsum slurry molded body 17. (2-4) Control Device The gypsum board manufacturing apparatus 10 of the present embodiment can have a control device 18 that controls the pressing device 20 and the like, as shown in FIGS. 1A to 1D .

[0076] The control device 18 controls the drive device 202 to change the distance between the pressing member 201 and the coating material 11. The control device 18 can switch between a pressing state in which the pressing member 201 presses the coating material 11 against the conveying device 21 and an open state in which the pressing member 201 is separated from the coating material 11.

[0077] The control device 18 can set the conveying device 21 to the pressed state when the conveying device 21 starts conveying the coating material 11, and then switch from the pressed state to the released state.

[0078] By the control device 18 performing the above control, the coating material 11 can be transported by the transport device 21 even before the gypsum slurry 14 is supplied.

[0079] As described above, when starting the production of gypsum boards, the conveyance of the covering material 11 is started, and then the supply of only water to the mixer 12 is started. After that, the supply and kneading of raw materials for the gypsum slurry, such as calcined gypsum, to the mixer 12 is started, and the supply of the gypsum slurry onto the covering material 11 is also started.

[0080] To prevent clogging inside the mixer 12 or in the piping for supplying the gypsum slurry 14, only water is supplied to the mixer 12 before the supply of the calcined gypsum or the like as described above. The water supplied to the mixer 12 is also supplied onto the covering material 11 before the supply of the gypsum slurry. As described above, the point on the covering material 11 where only water is first supplied is defined as the water supply start point 11A.

[0081] 1B and 1C, the supply of the gypsum slurry 14 onto the covering material 11 is started. As described above, at this time, the point on the covering material 11 where the gypsum slurry 14 is first supplied is defined as a slurry supply start point 11B.

[0082] There is no particular limitation on the timing at which the control device 18 switches from the pressed state to the open state. For example, the control device 18 preferably switches from the pressed state to the open state before the portion of the covering material 11 where the gypsum slurry 14 supplied from the mixer 12 is placed reaches the point (position) at which the pressing device 20 is placed. That is, the control device 18 preferably switches from the pressed state to the open state before the slurry supply starting point 11B reaches the point at which the pressing device 20 is placed.

[0083] If the portion of the coating material 11 where the gypsum slurry 14 supplied from the mixer 12 is placed continues to be pressed even after reaching the point where the pressing device 20 is placed, the gypsum slurry 14 may overflow from the coating material 11 due to the pressing force of the pressing member 201, etc.

[0084] When the gypsum slurry 14 overflows from the covering material 11, the gypsum slurry 14 overflowing from the covering material 11 may adhere to the belt 212, the pulley 211, and the roll 213, causing slippage between the belt 212 and the pulley 211. Furthermore, the gypsum slurry 14 adhering to the belt 212 may adhere to the covering material 11 of a subsequent product, or the gypsum slurry adhering to the belt 212 may harden, causing dents, streaks, or the like in the subsequent product.

[0085] Meanwhile, the control device 18 switches the state from the pressing state to the release state before the portion of the covering material 11 where the gypsum slurry 14 supplied from the mixer 12 is placed reaches the point where the pressing device 20 is placed, thereby preventing the gypsum slurry from spilling out of the covering material 11. This prevents the gypsum slurry 14 from adhering to the belt 212 or the like, causing the above-mentioned slippage, or preventing the gypsum slurry 14 from adhering to subsequent products.

[0086] Furthermore, when the water supply starting point 11A and the subsequent portion of the coating material 11 where only water is placed reach the portion where the coating material 11 is pressed against the conveyor 21 by the pressing member 201, the pressing force of the pressing member 201 may cause water to spill out of the coating material 11. If water spills out of the coating material 11, the belt 212, the pulley 211, and the roll 213 may become wet, which could cause the belt 212 and the pulley 211 to slip, or the subsequent coating material 11 to stick to the belt 212 and fall between the conveyor 21, resulting in damage to the coating material 11. Furthermore, the coating material 11 used for the subsequent product may become wet, causing the surface of the coating material 11 of the product to wrinkle. Therefore, it is more preferable that the control device 18 switch from the pressed state to the released state before the portion of the coating material 11 where only water supplied from the mixer 12 is placed reaches the point (position) where the pressing device 20 is placed.

[0087] As described above, the portion of the covering material 11 where only the water supplied from the mixer 12 is disposed refers to the portion where the water is supplied to the covering material 11 via the mixer 12 by supplying only water to the mixer 12 prior to the start of preparation of a gypsum slurry in the mixer 12. That is, the portion of the covering material 11 where only the water supplied from the mixer 12 is disposed refers to the region between the water supply starting point 11A and the slurry supply starting point 11B shown in Figures 1B and 1C. For this reason, it is more preferable that the control device 18 switch from the pressing state to the open state before the water supply starting point 11A reaches the point where the pressing device 20 is disposed.

[0088] After only water is supplied from the mixer 12, the gypsum slurry continues to be supplied from the mixer 12. Therefore, in either of the above cases, it is preferable that the control device 18 keeps the pressing device 20 in the open state after opening the pressing device 20.

[0089] In addition, if the gypsum board manufacturing apparatus 10 has multiple pressing devices 20 along the conveying path of the covering material 11, the control device 18 can select the timing for switching each pressing device 20 from a pressing state to an open state.

[0090] As described above, it is preferable that the pressing device 20 be switched from the pressing state to the open state before the slurry supply starting point 11B reaches the location where the pressing device 20 is disposed. In this case, it is preferable that the pressing device 20 be in the pressing state and press the coating material 11 against the conveying device 21 until just before the slurry supply starting point 11B reaches the location where the pressing device 20 is disposed.

[0091] It is more preferable that the pressing device 20 be switched from the pressing state to the open state before the water supply starting point 11A reaches the location where the pressing device 20 is placed. In this case, it is preferable that the pressing device 20 be in the pressing state and press the coating material 11 against the conveying device 21 until just before the water supply starting point 11A reaches the location where the pressing device 20 is placed.

[0092] The time it takes for the water supply start point 11A and the slurry supply start point 11B to reach the point where the pressing device 20 is located varies depending on the production speed (conveying speed). For this reason, it is preferable that the control device 18 adjusts and selects the timing for switching the pressing device 20 from the pressing state to the open state depending on the time it takes for the water supply start point 11A and the like to reach the point where the pressing device 20 is located. Furthermore, it is preferable to adjust the position of the pressing device 20 depending on the time from the start of the supply of water alone until the start of the supply of the gypsum slurry, the supply speed of the gypsum slurry, and the like, so that the coating material 11 can be transported by the transporting device 21 depending on the weight of the gypsum slurry placed on the coating material 11.

[0093] For example, as shown in FIG. 1A, after the conveyance of the coating material 11 is started and before the supply of water or gypsum slurry is started, all pressing devices 20 arranged in the conveyance path of the coating material 11 can be in a pressing state, i.e., the pressing members 201 can be in a state in which the coating material 11 is pressed against the conveyance devices 21.

[0094] 1B and 1C, the supply of only water onto the coating material 11 is started, and then the supply of gypsum slurry 14 is started. Since the time from the start of the supply of the gypsum slurry is longer in Fig. 1C than in Fig. 1B, the region where the gypsum slurry 14 is supplied, i.e., the region that becomes the gypsum slurry formed body 17, is longer. As shown in Fig. 1B and 1C, the water supply start point 11A and the slurry supply start point 11B move downstream of the conveyance path of the coating material 11.

[0095] In FIG. 1B, only one pressing device 20, which is located most upstream along the conveying path of the coating material 11 and which is close to the water supply starting point 11A, is in an open state.

[0096] In FIG. 1C, only the three pressing devices 20 from the upstream along the conveyance path of the coating material 11, which has passed the water supply starting point 11A, are in an open state.

[0097] Thereafter, as shown in FIG. 1D, when the production of gypsum boards reaches a steady state and gypsum boards are continuously produced, all pressing devices 20 are opened and remain in the open state.

[0098] For example, a signal (command) to supply water to the mixer 12 or a signal (command) to supply a raw material for gypsum slurry to the mixer 12 may be configured to be detected as the timing when water or gypsum slurry is supplied to the coating material 11. In this case, the timing when the water supply start point 11A or the slurry supply start point 11B of the coating material 11 reaches the point where the pressing device 20 is located can be calculated based on the detected timing when water or gypsum slurry is supplied to the coating material 11 and the conveying speed of the coating material 11 by the conveying device 21, etc. Then, the control device 18 can control the pressing device 20 in accordance with this timing.

[0099] If necessary, the device may be configured to detect the rotation speed of the pulleys 211 of the conveying device 21, the conveying speed of the coating material 11, etc., so that the conveying speed of the coating material 11 by the conveying device 21, etc. can be measured and calculated accordingly. Also, a communication line may be provided between the control device 18 and the mixer 12, so that the timing at which water or gypsum slurry is supplied from the mixer 12 to the coating material 11 can be notified to the control device 18.

[0100] The gypsum board manufacturing apparatus 10 of the present embodiment may also have a detection device 19 (see FIGS. 1A to 1D ) for detecting that the water supply start point 11A or the slurry supply start point 11B of the covering material 11 has reached the point where the pressing device 20 is disposed. The arrangement and configuration of the detection device 19 are not particularly limited.

[0101] The detection device 19 can be placed, for example, at the outlet of the pipeline 13 of the mixer 12, or at any location on the conveying path of the coating material 11, for example, upstream of the pressing device 20 on the conveying path of the coating material 11 and adjacent to the pressing device 20.

[0102] Furthermore, the detection device 19 may be configured as an imaging device that captures an image of the surface of the coating material 11, and may be configured to detect the water supply start point 11A, the slurry supply start point 11B, the portion where only water is disposed, and the portion where gypsum slurry is disposed in the coating material 11 from the captured image. The detection device 19 may be configured to detect the water supply start point 11A, the slurry supply start point 11B, the portion where only water is disposed, and the portion where gypsum slurry is disposed in the coating material 11 using various sensors. The detection device 19 may include multiple types of detection devices depending on the detection target, such as a water detection device that detects water and a gypsum slurry detection device that detects gypsum slurry.

[0103] The control device 18 may include a CPU, which is an arithmetic processing unit for performing calculations necessary for control, RAM and ROM, which are main storage devices, an auxiliary storage device, an input / output interface, a display device, which is an output device, etc. The CPU, main storage device, auxiliary storage device, input / output interface, and output device of the control device 18 can be interconnected via a bus. All of the above components of the control device 18 do not need to be housed in the same housing; for example, the auxiliary storage device and display device may be provided externally. The auxiliary storage device is a storage device such as an SSD or HDD.

[0104] Note that CPU stands for Central Processing Unit, RAM stands for Random Access Memory, ROM stands for Read Only Memory, SSD stands for Solid State Drive, and HDD stands for Hard Disk Drive.

[0105] Examples of input / output interfaces include wired or wireless interfaces for exchanging signals (commands) to supply water or signals (commands) to supply raw materials for gypsum slurry, detection data from the detection device 19, control variables from the drive device 202, etc.

[0106] Examples of the input / output interface include user interfaces such as a touch panel, keyboard, and operation buttons for selecting control conditions.

[0107] The control device 18 can be configured with a personal computer (PC) or the like. Therefore, the above-mentioned parts of the control device 18 may be realized by software and hardware working together in an information processing device such as a personal computer, in which a CPU executes a program pre-stored in a main memory or the like. (2-5) Forming Device As shown in Figures 1A to 1D, the gypsum board manufacturing apparatus 10 of this embodiment can also have a forming device 16.

[0108] The first gypsum board base paper 111 and the second gypsum board base paper 112 being transported within the gypsum board manufacturing apparatus 10 reach the molding device 16. Here, gypsum slurry 14 is supplied from the mixer 12 through a pipeline 13 between the first gypsum board base paper 111 and the second gypsum board base paper 112. Therefore, a continuous laminate can be formed in which a layer formed by the gypsum slurry 14 is disposed between the first gypsum board base paper 111 and the second gypsum board base paper 112.

[0109] Specifically, for example, gypsum slurry 14 having a predetermined density is supplied and deposited on a first gypsum board base paper 111 that is continuously conveyed. Then, both widthwise ends of the first gypsum board base paper 111 are folded along predetermined score lines, extending upward and then inward, thereby partially enveloping the deposited layer of gypsum slurry 14. After this, a second gypsum board base paper 112, conveyed at the same speed, can be laid on top of the deposited layer of gypsum slurry 14 partially enveloping the first gypsum board base paper 111. The gypsum board is then passed through a forming device 16 that determines the thickness and width of the gypsum board, and is then formed. A gypsum board can also be formed using the above procedure. In this case, a layer of gypsum slurry with a single density is formed between the first gypsum board base paper 111 and the second gypsum board base paper 112. The present invention is not limited to this configuration, and layers of multiple types of gypsum slurries with different densities can also be formed.

[0110] In this way, the molding device 16 of the gypsum board manufacturing apparatus 10 can carry out a molding process for molding the gypsum slurry, thereby manufacturing the gypsum slurry molded body 17. (2-6) Rough Cutting Device, Dryer, Cutting Device The gypsum board manufacturing apparatus 10 of the present embodiment can also be provided with a rough cutting device 22, a dryer, a cutting device (not shown), or the like, for example, downstream of the molding device 16, as needed.

[0111] The dryer can reduce excess moisture in the gypsum slurry molded body.

[0112] The produced gypsum slurry molded body 17 can be roughly cut into a desired size by the rough cutting device 22. In Figs. 1A to 1D, a rotary cutter is shown as the rough cutting device 22.

[0113] 1A to 1D includes an upper cutter 22 A and a lower cutter 22 B. The upper cutter 22 A and the lower cutter 22 B include rotating rolls 221 A and 221 B and blades 222 A and 222 B attached to the rotating rolls 221 A and 221 B, respectively, and can roughly cut the gypsum slurry molded body 17 and the like by rotating in the direction indicated by the arrow in FIG.

[0114] However, the configuration of the rough cutting device 22 is not limited to the above embodiment.

[0115] It is preferable to start operating the rough cutting device 22 after the supply of the gypsum slurry 14 has started and the gypsum slurry molded body 17 has passed the cutting position of the rough cutting device 22. That is, it is preferable to start operating the rough cutting device 22 after the slurry supply start point 11B has passed the rough cutting device 22. Therefore, the rough cutting device 22 can be prevented from operating while only the coating material 11 is passing the cutting position of the rough cutting device 22. Then, the portion where only the coating material 11 is layered, which is generated at the start of production of the gypsum board, can be cut by the rough cutting device 22 together with the portion including the gypsum slurry molded body 17, and can be removed from the production line.

[0116] The gypsum board manufacturing apparatus 10 can have one or more rough cutting devices 22 and cutting devices as needed. The gypsum board manufacturing apparatus 10 can have, for example, a first cutting device (rough cutting device 22) that roughly cuts the manufactured gypsum slurry molded body 17 or the gypsum board for the purpose of installing the gypsum board in a dryer. The gypsum board manufacturing apparatus 10 can also have a second cutting device (cutting device) that cuts the gypsum board to the size of the final product. [Gypsum Board Manufacturing Method] The gypsum board manufacturing method of this embodiment relates to a gypsum board manufacturing method for manufacturing a gypsum board in which at least the upper and lower surfaces of the gypsum core are covered with a coating material, and can have a coating material conveying process and a gypsum slurry supplying process, which will be described below.

[0117] The method for manufacturing a gypsum board according to this embodiment can be carried out using the gypsum board manufacturing apparatus already described, and therefore, the description of the matters already described will be omitted.

[0118] In the coating material transport step, the coating material 11 can be transported by a transport device 21 .

[0119] In the gypsum slurry supplying step, a gypsum slurry 14 containing calcined gypsum and water prepared by a mixer 12 can be supplied onto the covering material 11 .

[0120] After the start of the coating material conveying process, the gypsum slurry supplying process can be started. After the start of the coating material conveying process, only water is supplied to the mixer 12 before the start of the gypsum slurry supplying process, and then the supply and kneading of raw materials for the gypsum slurry, such as calcined gypsum, to the mixer 12 is started. Thereafter, the supply of the gypsum slurry onto the coating material 11, i.e., the gypsum slurry supplying process, is started.

[0121] In the method for manufacturing a gypsum board according to the present embodiment, at the start of the coating material transport step, the pressing member 201 of the pressing device 20 can be in a pressing state in which the coating material 11 is pressed against the transport device 21. Then, the pressing member 201 of the pressing device 20 can be released from the coating material 11 and put into an open state.

[0122] As already described, the pressing device 20 has a pressing member 201 that presses the coating material 11 being transported by the transport device 21 against the transport device 21, and a driving device 202 that changes the distance between the pressing member 201 and the coating material 11.

[0123] In the method for manufacturing a gypsum board according to this embodiment, the coating material conveying process and the gypsum slurry supplying process can be continuously carried out after the start of each process. The pressing process is a process in which the pressing member 201 of the pressing device 20 presses the coating material 11 against the conveying device 21, and the releasing process is a process in which the pressing member 201 of the pressing device 20 is released from the coating material. In this case, the pressing process can be carried out continuously from the start of the coating material conveying process until a predetermined timing. After the pressing process is completed, the releasing process can be carried out.

[0124] The timing at which the pressing step ends and the releasing step starts is not particularly limited, and the pressing step can be switched to the releasing step at any timing.

[0125] For example, with regard to the pressing device 20, after the start of the gypsum slurry supply process, it is preferable to switch from the pressing state to the open state before the portion of the covering material 11 where the gypsum slurry supplied from the mixer 12 is placed reaches the point where the pressing device 20 is placed.

[0126] That is, it is preferable to finish the pressing process and start the releasing process before the slurry supply starting point 11B of the coating material 11 reaches the point where the pressing device 20 is placed. After the releasing process is started, the releasing process can be continued.

[0127] As described above, before the start of the gypsum slurry supplying step, only water is supplied to the mixer 12, and the supplied water is supplied onto the covering material 11. That is, the method for manufacturing a gypsum board of the present embodiment can also have a water supplying step in which only water is supplied from the mixer 12 to the covering material 11 before the start of the gypsum slurry supplying step.

[0128] In this case, it is more preferable that the pressing device 20 be switched from the pressed state to the released state after the water supply step is started and before the portion of the covering material 11 where only the water supplied from the mixer 12 is placed reaches the point where the pressing device 20 is placed. That is, the pressing step can be completed and the releasing step can be started before the water supply starting point 11A of the covering material 11 reaches the point where the pressing device 20 is placed. After the releasing step is started, the releasing step can be continued.

[0129] In addition, if the gypsum board manufacturing apparatus 10 has multiple pressing devices 20 along the conveying path of the covering material 11, the timing for switching from the pressing state to the release state for each pressing device 20, i.e., the timing for ending the pressing process and performing the release process, can be selected.

[0130] It is preferable to arrange an appropriate number of pressing devices 20 at appropriate positions relative to the production line so that the coating material 11 can be transported by the transport device 21, depending on the length and layout of the production line of the gypsum board manufacturing apparatus 10, the production speed, the weight of the gypsum slurry 14 placed on the coating material 11, etc. The pressing device 20 is preferably in a pressing state, pressing the coating material 11 against the transport device 21, until just before the slurry supply start point 11B reaches the point where the pressing device 20 is arranged. It is also more preferable that the pressing device 20 is in a pressing state, pressing the coating material 11 against the transport device 21, until just before the water supply start point 11A reaches the point where the pressing device 20 is arranged. For this reason, it is preferable to adjust the arrangement of the pressing device 20 depending on the time from when the supply of only water from the mixer 12 starts until the supply of the gypsum slurry starts, the supply rate of the gypsum slurry, etc.

[0131] In addition to the coating material conveying step and the gypsum slurry supplying step, the gypsum board manufacturing method of this embodiment may further include, for example, the following gypsum slurry preparation step, molding step, hardening step, rough cutting step, drying step, etc. It may also include.

[0132] In the gypsum slurry preparation step, calcined gypsum, which is a raw material for the gypsum slurry, water, and, in some cases, various additives and foams are kneaded together to prepare the gypsum slurry.

[0133] In the forming step, the gypsum slurry can be formed into a plate shape.

[0134] In the hardening step, the gypsum slurry molded body obtained in the molding step can be hardened.

[0135] In the rough cutting step, the gypsum slurry molded body can be roughly cut by a rough cutting device.

[0136] In the drying step, the gypsum slurry formed body can be dried.

[0137] In the cutting step, the gypsum board can be cut by a cutting device.

[0138] Each step will be described using an example in which the gypsum board to be manufactured is a gypsum board. (Gypsum Slurry Preparation Step) In the gypsum slurry preparation step, calcined gypsum, water, and, in some cases, foam and various additives are further mixed to prepare a gypsum slurry.

[0139] For example, as explained in the gypsum board manufacturing apparatus, these raw material components can be kneaded using a mixer or the like to prepare a gypsum slurry. Note that the raw materials for the gypsum slurry have already been explained, so explanations will be omitted here. (Forming Process) In the forming process, the gypsum slurry obtained in the gypsum slurry preparation process can be formed into a plate shape. When the gypsum board to be manufactured is a gypsum board, in the forming process, the gypsum slurry can be supplied between two sheets of gypsum board base paper and formed into a plate shape.

[0140] For example, in a gypsum slurry preparation step, gypsum slurry 14 is prepared. Then, in a molding step, a continuous laminate can be formed in which a layer of gypsum slurry 14 is disposed between first gypsum board base paper 111 and second gypsum board base paper 112. Next, the gypsum board is passed through a molding device 16 that determines the thickness of the gypsum board, and molded into a plate, thereby forming a gypsum slurry molded body.

[0141] However, the present invention is not limited to the above embodiment, and in the molding process, a gypsum slurry having a desired density can be supplied between the gypsum board base papers and molded into a plate shape using a molding device. (Hardening Process) After the molding process, a hardening process can be carried out. The hardening process is a process for hardening the gypsum slurry molded body obtained in the molding process.

[0142] The hardening process can be carried out by the hydration reaction of the calcined gypsum (hemihydrate gypsum) in the gypsum slurry, which generates needle-shaped crystals of gypsum dihydrate and coagulates and solidifies. Therefore, the hardening process can be carried out by the reaction between the calcined gypsum added to the gypsum slurry and water within the gypsum slurry molded body formed in the molding process, and the hydration reaction of the calcined gypsum progresses. (Rough Cutting Process) In the rough cutting process, the gypsum slurry molded body 17 can be cut by the rough cutting device 22.

[0143] After the gypsum slurry molded body 17 is formed in the molding step, the gypsum slurry gradually hardens. Therefore, the rough cutting step can be performed, for example, during the hardening step or after the hardening step is completed. However, it is preferable to perform the rough cutting step after the hardening step has progressed to an extent that the gypsum slurry molded body 17 can be roughly cut.

[0144] The cutting step can be performed multiple times. Therefore, the method for manufacturing a gypsum board according to the present embodiment can also include a first cutting step, which can be referred to as a rough cutting step. In the first cutting step, the gypsum slurry molded body or the gypsum board can be roughly cut into a desired size depending on, for example, the size of a dryer used in the drying step described later.

[0145] Furthermore, the second cutting step (cutting step) can be performed, for example, after the drying step, and the gypsum board can be cut to a desired product size. (Drying Step) In the drying step, the gypsum slurry molded body 17 can be dried. In the drying step, excess moisture contained in the gypsum slurry molded body 17 can be dried. Note that a gypsum slurry molded body that has completed the hardening step can be supplied to the drying step. The drying step can be performed by force-drying the gypsum slurry molded body using a dryer.

[0146] The method for forcibly drying the gypsum slurry molded bodies with a dryer is not particularly limited, but for example, a dryer can be provided on a transport path of the gypsum slurry molded bodies, and the gypsum slurry molded bodies can be continuously dried by passing through the dryer. Alternatively, the gypsum slurry molded bodies can be transported into the dryer and dried in batches.

[0147] According to the method for manufacturing a gypsum board of this embodiment described above, the coating material can be transported by the transport device even after the coating material transport step has started and before the gypsum slurry is supplied. (Notes) (1) A gypsum board manufacturing apparatus according to one aspect of the present disclosure is a gypsum board manufacturing apparatus that manufactures gypsum boards in which at least the upper and lower surfaces of a gypsum core are covered with a coating material, and includes: a conveying device that conveys the coating material; a mixer that prepares a gypsum slurry containing calcined gypsum and water and supplies the gypsum slurry onto the coating material; a pressing device that has a pressing member that presses the coating material being conveyed by the conveying device against the conveying device and a driving device that changes the distance between the pressing member and the coating material; and a control device that controls the driving device to change the distance between the pressing member and the coating material, and switches between a pressing state in which the pressing member presses the coating material against the conveying device and an open state in which the pressing member is separated from the coating material, and the control device switches to the pressing state when the conveying device starts conveying the coating material, and then switches from the pressing state to the open state. (2) In (1), the control device may switch from the pressed state to the open state before a portion of the covering material where the gypsum slurry supplied from the mixer is placed reaches a point where the pressing device is placed. (3) In (1) or (2), the control device may switch from the pressed state to the open state before a portion of the covering material where only water supplied from the mixer is placed reaches a point where the pressing device is placed. (4) In any of (1) to (3), a plurality of the pressing devices may be arranged along the width of the covering material transported by the transport device. (5) In any of (1) to (4), a plurality of the pressing devices may be arranged along the transport direction of the covering material in the transport device.(6) In any of (1) to (5), a molding device that molds the coating material and the gypsum slurry into a gypsum slurry molded body and a rough cutting device that roughly cuts the gypsum slurry molded body are provided downstream in the conveying direction of the coating material from a point where the gypsum slurry is supplied from the mixer onto the coating material, and the pressing device may be disposed between the molding device and the rough cutting device. (7) In (6), the pressing device may be disposed between the molding device and a point away from the molding device by half the distance between the molding device and the rough cutting device. (8) In any of (1) to (7), the pressing device may have a resistance adding device that applies a force to the pressing member in a direction away from the coating material. (9) A method for manufacturing a gypsum board according to one aspect of the present disclosure is a method for manufacturing a gypsum board in which at least the upper and lower surfaces of a gypsum core are covered with a coating material, the method comprising: a coating material transporting step of transporting the coating material by a transporting device; and a gypsum slurry supplying step of supplying a gypsum slurry containing calcined gypsum and water prepared by a mixer onto the coating material, wherein at the start of the coating material transporting step, the pressing member of the pressing device has a pressing member that presses the coating material being transported by the transporting device against the transporting device and a driving device that changes the distance between the pressing member and the coating material, and the pressing member presses the coating material against the transporting device, and then switches the pressing member to an open state in which it is separated from the coating material. (10) In (9), the pressing device may be switched from the pressing state to the open state before the portion of the coating material where the gypsum slurry supplied from the mixer is placed reaches a point where the pressing device is placed. (11) In the method of (9) or (10), a water supplying step of supplying only water from the mixer to the covering material before the start of the gypsum slurry supplying step may be included, and the pressing device may be switched from the pressing state to the open state after the start of the water supplying step, during the time until a portion of the covering material where only the water supplied from the mixer is placed reaches a point where the pressing device is placed.

[0148] Although the gypsum board manufacturing apparatus and the gypsum board manufacturing method have been described above in the embodiments, the present invention is not limited to the above embodiments, etc. Various modifications and changes are possible within the scope of the gist of the present invention described in the claims.

[0149] This application claims priority based on Japanese Patent Application No. 2023-102665, filed with the Japan Patent Office on June 22, 2023, the entire contents of which are incorporated herein by reference.

[0150] 10 Gypsum board manufacturing apparatus 11 Covering material 111 First gypsum board base paper 112 Second gypsum board base paper 11A Water supply start point 11B Slurry supply start point 12 Mixer 121 Separation port 13 Pipe 14 Gypsum slurry 141 Point 15 Diversion roll 16 Forming device 17 Gypsum slurry formed body 18 Control device 19 Detection device 20, 20A to 20C, 20a to 20d Pressing device 201 Pressing member 202 Driving device 2021 Rod 203 Frame 203A Support 203B Point of action 2031 First end 2032 Second end 204 Support 205 Resistance adding device 2051 Weight 2052 Connecting member 2053 Pulley 21 Conveyor device 211 Pulley 212 Belt 213 Roll 213A Roll 213B Roll 22 Rough cutting device 22A Upper cutter 221A Rotating roll 222A Blade portion 22B Lower cutter221B Rotating roll 222B Blade portion 301, 302 Support member L Distance L1 Distance L2 Distance A Double arrow B Double arrow C Double arrow

Claims

1. A gypsum board manufacturing apparatus for manufacturing gypsum boards in which at least the upper and lower surfaces of a gypsum core are covered with a covering material, comprising: a conveying device for conveying the covering material; a mixer for preparing a gypsum slurry containing calcined gypsum and water and supplying the gypsum slurry onto the covering material; a pressing device having a pressing member for pressing the covering material conveyed by the conveying device against the conveying device and a drive device for changing the distance between the pressing member and the covering material; and a control device for controlling the drive device to change the distance between the pressing member and the covering material, and switching between a pressing state in which the pressing member presses the covering material against the conveying device and an open state in which the pressing member is separated from the covering material, wherein the control device switches the conveying device to the pressing state when the conveying device starts conveying the covering material, and then switches from the pressing state to the open state.

2. The gypsum board manufacturing apparatus of claim 1, wherein the control device switches from the pressed state to the open state before the portion of the covering material on which the gypsum slurry supplied from the mixer is placed reaches the point where the pressing device is placed.

3. The gypsum board manufacturing apparatus of claim 1, wherein the control device switches from the pressed state to the open state before the portion of the covering material where only water supplied from the mixer is placed reaches the point where the pressing device is placed.

4. A gypsum board manufacturing apparatus as described in any one of claims 1 to 3, wherein a plurality of the pressing devices are arranged along the width of the covering material transported by the transporting device.

5. A gypsum board manufacturing apparatus as described in any one of claims 1 to 3, wherein a plurality of the pressing devices are arranged along the conveying direction of the covering material in the conveying device.

6. A gypsum board manufacturing apparatus as described in any one of claims 1 to 3, further comprising: a molding device for molding the covering material and the gypsum slurry to form a gypsum slurry molded body, and a rough cutting device for roughly cutting the gypsum slurry molded body, which are located downstream in the conveying direction of the covering material from a point where the gypsum slurry is supplied from the mixer onto the covering material; and a pressing device disposed between the molding device and the rough cutting device.

7. The gypsum board manufacturing apparatus according to claim 6, wherein the pressing device is disposed between the molding device and a point away from the molding device that is half the distance between the molding device and the rough cutting device.

8. A gypsum board manufacturing apparatus as claimed in any one of claims 1 to 3, wherein the pressing device has a resistance adding device which applies a force in a direction in which the pressing member moves away from the covering material.

9. A method for manufacturing a gypsum board in which at least the upper and lower surfaces of a gypsum core are covered with a covering material, comprising: a covering material transporting process for transporting the covering material by a transporting device; and a gypsum slurry supplying process for supplying a gypsum slurry containing calcined gypsum and water prepared by a mixer onto the covering material, wherein at the start of the covering material transporting process, a pressing member of a pressing device having a pressing member for pressing the covering material being transported by the transporting device against the transporting device and a driving device for changing the distance between the pressing member and the covering material presses the covering material against the transporting device, and then the pressing member is released from the covering material.

10. A method for manufacturing a gypsum board as described in claim 9, wherein the pressing device switches from the pressed state to the open state before the portion of the covering material on which the gypsum slurry supplied from the mixer is placed reaches the point where the pressing device is placed.

11. A method for manufacturing a gypsum board as described in claim 9, further comprising a water supplying process for supplying only water from the mixer to the covering material before the start of the gypsum slurry supplying process, and wherein the pressing device is switched from the pressed state to the open state after the start of the water supplying process, before the portion of the covering material where only the water supplied from the mixer is placed reaches a point where the pressing device is placed.