CN117986034A - Method for preparing hydrophobic film on surface of gypsum board - Google Patents

Abstract

The invention discloses a method for preparing a hydrophobic film on the surface of a gypsum board, which comprises the following steps: and (3) smearing an alkali solution mixed with methyl hydrogen silicone oil on the front surface of the lower facing paper, and then drying the wet gypsum board. In the process of drying the gypsum board wet board under alkaline conditions, the Si-H which is not hydrolyzed and water molecules evaporated from the board core continue to hydrolyze into Si-OH, part of the Si-OH is combined with the facing paper fiber to fix the hydrophobic group on the front surface of the gypsum board, and the other Si-OH forms a more stable-Si-O-covalent network through self-condensation polymerization to cover the front surface of the gypsum board, so that the front surface of the gypsum board forms a hydrophobic film.

Description

Method for preparing hydrophobic film on surface of gypsum board

Technical Field

The invention relates to the field of gypsum board production lines, and in particular to a method for preparing a hydrophobic film on the surface of a paper-faced gypsum board.

Background technique

The main components of paper-faced gypsum board are gypsum, facing paper and some additives. Both gypsum and facing paper have the characteristics of easy moisture absorption, and the surface of the facing paper is hydrophilic. In an environment with high humidity, moisture will penetrate through the paper surface and enter the gypsum core layer.

In order to solve this problem, a hydrophobic film can be formed on the front side of the gypsum board to prevent moisture from penetrating through the paper surface and entering the gypsum core layer. It is known that the lower facing paper of the gypsum board is the use side, and the upper facing paper of the gypsum board usually faces the wall or ceiling and is generally not affected by the humid environment. Therefore, it is usually only necessary to form a hydrophobic film on the front side of the lower facing paper.

Summary of the invention

The object of the present invention is to provide a method for preparing a hydrophobic film on the surface of a paper-faced gypsum board, so as to solve the technical problem of how to form a hydrophobic film on the front side of the lower face paper of the gypsum board.

In order to solve the above technical problems, the present invention specifically provides the following technical solutions:

A method for preparing a hydrophobic film on the surface of a paper-faced gypsum board comprises the following steps: applying an alkaline solution mixed with methyl hydrogen silicone oil on the front surface of a lower face paper, and then drying the wet gypsum board.

Furthermore, after the lower face paper passes through the lower face paper deviation correcting machine, the alkaline solution is applied to the front side of the lower face paper.

Furthermore, before the lower face paper passes through the lower face paper notching machine, the alkaline solution is applied to the front side of the lower face paper.

Furthermore, a second lower face paper deflection corrector is added between the lower face paper deflector and the lower face paper notching machine, and after the alkaline solution is applied to the front side of the lower face paper, the lower face paper passes through the second lower face paper deflector.

Furthermore, blank areas with a width of 10 mm to 15 mm are reserved on both sides of the front side of the lower face paper, and the alkaline solution is applied to the areas outside the blank areas.

Furthermore, the step of applying an alkaline solution mixed with methyl hydrogen silicone oil on the front side of the lower face paper includes: spraying the alkaline solution on the front side of the lower face paper using a spray gun; and smoothing the alkaline solution attached to the front side of the lower face paper using an applying component.

Furthermore, the number of the spray guns is several, and the several spray guns are arranged side by side at equal intervals along the width direction of the lower face paper, and each of the spray guns can be opened or closed independently; the number of the coating components is at least 2, and the multiple coating components form a continuous and uninterrupted coating area in the width direction of the lower face paper, wherein the position of at least one coating component in the width direction of the lower face paper can be adjusted to change the overall width of the coating area; the step of using the spray gun to spray the alkaline solution on the front side of the lower face paper includes: selectively opening some of the spray guns so that the alkaline solution sprayed on the lower face paper by the spray gun avoids the blank area; the step of using the coating component to smooth the alkaline solution attached to the front side of the lower face paper includes: adjusting the position of the coating component to change the overall width of the coating area so that the edge of the coating area fits the edge of the blank area.

Furthermore, the step of applying an alkaline solution mixed with methyl hydrogen silicone oil on the front side of the lower face paper also includes: setting a supporting component on the side of the lower face paper facing away from the applying component, the supporting component including a smooth line or surface for supporting the back side of the lower face paper, and using the supporting component to offset the force applied by the applying component to the front side of the lower face paper.

On the other hand, the step of applying an alkaline solution mixed with methyl hydrogen silicone oil on the front side of the lower face paper also includes: setting a belt conveyor on the side of the lower face paper facing away from the application component, the transmission surface of the belt conveyor is in contact with the back side of the lower face paper, the transmission speed of the belt conveyor is in the same direction and speed as the linear speed of the lower face paper, and the width of the transmission surface of the belt conveyor is greater than the width of the lower face paper.

Furthermore, the step of applying an alkaline solution mixed with methyl hydrogen silicone oil on the front side of the lower face paper also includes: using a color sensor to detect the printed pattern on the front side of the lower face paper, calculating the linear speed of the lower face paper according to the interval time between the appearance of two adjacent printed patterns, and then adjusting the transmission speed of the belt conveyor so that the transmission speed of the belt conveyor is equal to the linear speed of the lower face paper.

Compared with the prior art, this application has the following beneficial effects:

Provided is a method for preparing a hydrophobic film on the surface of a paper-faced gypsum board. The method comprises the following steps: applying an alkaline solution mixed with methyl hydrogen silicone oil on the front side of a lower face paper, wherein the methyl hydrogen silicone oil contains a plurality of Si-H groups with active chemical properties, and then drying the wet gypsum board. In the process of drying the paper-faced gypsum board under alkaline conditions, the unhydrolyzed Si-H and the water molecules evaporated from the board core continue to hydrolyze into Si-OH, a part of the Si-OH is combined with the face paper fibers to fix the hydrophobic groups to the front side of the gypsum board, and the other Si-OH forms a more stable -Si-O- covalent network through self-condensation and covers the front side of the gypsum board, so that a hydrophobic film is formed on the front side of the gypsum board.

BRIEF DESCRIPTION OF THE DRAWINGS

In order to more clearly illustrate the implementation of the present invention or the technical solution in the prior art, the following briefly introduces the drawings required for the implementation or the description of the prior art. Obviously, the drawings in the following description are only exemplary, and for ordinary technicians in this field, other implementation drawings can be derived from the provided drawings without creative work.

FIG1 is a perspective view of a coating device according to an embodiment of the present invention;

FIG2 is a bottom view of a coating device according to an embodiment of the present invention;

Fig. 3 is a cross-sectional view taken along the A-A direction of Fig. 2 and an enlarged view of its local structure;

The numbers in the figure represent the following:

1-lower protective paper; 11-blank area; 2-applying component; 21-rag; 22-elastic plate; 3-spray gun; 31-solenoid valve; 4-servo slide; 5-pipeline; 6-belt conveyor; 7-color sensor.

Detailed ways

The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

The following provides a method for preparing a hydrophobic film on the surface of a gypsum board, comprising the following steps:

Before drying the gypsum board, an alkaline solution mixed with methyl hydrogen silicone oil is applied to the front side of the lower face paper 1, and then the gypsum board is dried.

The hydrophobic film is formed by the following principles:

The alkaline solution can be potassium hydroxide. Methyl hydrogen silicone oil is a highly polymerized organic compound with multiple chemically active Si-H groups in its molecules. In the process of drying the gypsum board under alkaline conditions, the unhydrolyzed Si-H and the water molecules evaporated from the board core continue to hydrolyze into Si-OH. A part of Si-OH combines with the facing paper fibers to fix the hydrophobic group to the front of the gypsum board, and the other Si-OH forms a more stable -Si-O- covalent network through self-condensation to cover the front of the gypsum board, finally forming a hydrophobic film on the front of the gypsum board.

It can be seen that the other steps of the method for producing gypsum board do not require any changes. It is only necessary to apply an alkaline solution mixed with methyl hydrogen silicone oil on the front side of the lower face paper 1 before the wet gypsum board is dried to obtain a gypsum board with a hydrophobic film formed on the front side.

Preferably:

Before the lower face paper 1 passes through the lower face paper notching machine, an alkaline solution mixed with methyl hydrogen silicone oil is applied to the front side of the lower face paper 1 .

The location for applying the alkaline solution mixed with methyl hydrogen silicone oil is selected between the lower face paper correction machine and the lower face paper scoring machine of the gypsum board production line. This is because it is difficult to apply the alkaline solution to the scored portion of the lower face paper 1, and it is difficult to form a hydrophobic layer at the edge of the lower face paper 1 of the gypsum board finally obtained. Therefore, it is necessary to apply the alkaline solution before scoring so that a hydrophobic layer can be formed on both sides of the scored portion of the lower face paper 1.

Furthermore, since glue needs to be applied to the top surface of the flange after the upper face paper is erected so that the upper face paper can be attached to the top surface of the flange, the edges on both sides of the upper face paper cannot be coated with alkaline solution, otherwise the stickiness of the glue attached to the front side of the lower face paper 1 will be reduced.

In the step of applying the alkaline solution mixed with methyl hydrogen silicone oil on the front side of the lower face paper 1, the following conditions need to be defined:

A blank area 11 with a width of 10 mm to 15 mm is left on both sides of the lower face paper 1 , and an alkaline solution mixed with methyl hydrogen silicone oil is applied to the area outside the blank area 11 .

Since the deviation of the lower face paper 1 during the transmission process will make the position of the blank area 11 difficult to control, the following conditions need to be defined: after the lower face paper 1 passes through the lower face paper deviation correcting machine, an alkaline solution mixed with methyl hydrogen silicone oil is applied to the front side of the lower face paper 1.

Furthermore, since the widths of the lower facing papers 1 of gypsum boards of different specifications are different, it is necessary to prepare coating devices of different widths for the lower facing papers 1 of different widths.

The coating device comprises at least two coating components 2, which are arranged on the transmission path of the lower face paper 1 and are used to coat the alkaline solution on the front side of the lower face paper 1;

The two application components 2 can move along the width direction of the lower face paper 1 so that the edge of the application component 2 can be close to one side of the lower face paper 1 and away from the other side of the lower face paper 1, the projections of the two application components 2 in the width direction of the lower face paper 1 are staggered from each other, and the projections of the two application components 2 in the length direction of the lower face paper 1 are partially overlapped, so that the two application components 2 can respectively apply from the middle of the lower face paper 1 to one side of the lower face paper 1, and repeat the application in the middle of the lower face paper 1.

If the width of the largest gypsum board is 2 times or more than the width of the smallest gypsum board, then two coating components 2 are not sufficient to accommodate gypsum boards of any specifications. The operator needs to replace coating components 2 of different lengths to adapt to changes in the width of the gypsum board, or expand the number of coating components 2 to 3 or more.

When the smearing device includes three smearing components 2 , one of the smearing components 2 is fixed in the middle of the lower face paper 1 and is symmetrical with respect to the center line of the lower face paper 1 , and the other two smearing components 2 are respectively located on both sides of the smearing component 2 .

The above embodiment can also be differentiated into more embodiments, for example:

The smearing device includes three smearing components 2; one of the smearing components 2 is fixed in the middle of the lower face paper 1 and is symmetrical with respect to the center line of the lower face paper 1; the other two smearing components 2 are respectively located on both sides of the smearing component 2, and the two smearing components 2 can both move along the width direction of the lower face paper 1, and their projections in the width direction of the lower face paper 1 overlap with each other.

Therefore, in many embodiments, the application component 2 only needs to meet the following conditions:

The overall width of the plurality of application members 2 in the width direction of the lower face paper 1 can be adjusted, and the plurality of application members 2 do not interfere with each other when the overall width is adjusted.

The coating component 2 can be a rag 21, a brush, a roller brush, a spray gun 3 or other existing tools for coating liquid on the surface of the product, and the alkaline solution can be quantitatively transmitted to the rag 21, the brush, the roller brush or the spray gun 3 through a pipeline.

The following preferred technical means are adopted in this embodiment.

The coating device comprises: a spray gun 3 and a linear drive;

A plurality of spray guns 3 are arranged side by side at equal intervals along the width direction of the lower face paper 1, each spray gun 3 is connected to an alkali solution source, and each spray gun 3 can be independently opened to spray the alkali solution onto the surface of the lower face paper 1;

The number of linear drives is at least 2, and the 2 linear drives are respectively connected to 1 coating component 2. The driving direction of the linear drive is parallel to the width direction of the lower protective paper 1. When the number of coating components 2 is 3, the coating component 2 located in the middle does not need to be driven by the linear drive.

Specifically, the linear drive adopts a servo slide 4 .

Each spray gun 3 is connected to a pipe 5 with an alkaline solution flowing therein via a separate solenoid valve 31. The alkaline solution can be stored inside a box (not shown in the figure). The box is connected to the pipe 5 and is located at a high place, so that the inside of the pipe 5 has a pressure that enables the alkaline solution to be sprayed out through the spray gun 3.

The smearing component 2 includes: a rag 21 and an elastic plate 22; the rag 21 is fixedly connected to the elastic plate 22, the portion where the elastic plate 22 and the rag 21 are connected is a rectangular shape, and the edge of the rag 21 exceeds the edge of the elastic plate 22, and the rag 21 always adheres to the surface of the lower protective paper 1 under the action of the rebound force of the elastic plate 22.

When the size of the gypsum board changes, the solenoid valve 31 is selectively opened and closed to change the spraying width of the spray gun 3. At the same time, the servo slide 4 drives the elastic plate 22 to move so that the alkaline solution sprayed by the spray gun 3, after being smoothed by the rag 21, just covers the area outside the blank area 11 on both sides of the lower face paper 1.

Furthermore, since at least two coating components 2 are asymmetric relative to the center line of the lower facing paper 1, when each coating component 2 applies alkaline solution to the front side of the lower facing paper 1, the lower facing paper 1 will deflect to one side, causing the corrected lower facing paper 1 to shift again.

In order to solve this problem, a device is needed to prevent the coating component 2 from exerting a force on the lower face paper 1 to cause it to deflect, or a lower face paper correction machine (not shown) is added between the coating device and the lower face paper scoring machine.

Among them, the device for preventing the smearing component 2 from applying a force to the lower face paper 1 to cause it to deviate includes: a supporting component, which is arranged on the side of the lower face paper 1 facing away from the smearing component 2, and the supporting component is used to support the back side of the lower face paper 1, so that when the smearing component 2 applies a force to the front side of the lower face paper 1, the supporting component applies a reverse force, and the two forces offset each other to avoid the lower face paper 1 from deviating.

The supporting member may be a roller, a smooth metal plate or the like, which is an existing technical means that will not damage the lower face paper 1 when rubbing against the back side of the lower face paper 1 .

The following preferred technical means are adopted in this embodiment.

The device for preventing the smearing component 2 from exerting a force on the lower face paper 1 to cause it to deviate includes: a belt conveyor 6, the transmission surface of the belt conveyor 6 is in contact with the back of the lower face paper 1, the transmission speed of the belt conveyor 6 is in the same direction and speed as the linear speed of the lower face paper 1, and the width of the transmission surface of the belt conveyor 6 is greater than the width of the lower face paper 1.

Furthermore, in order to ensure that the transmission speed of the belt conveyor 6 is the same as the linear speed of the lower protective paper 1, in this embodiment, the linear speed of the lower protective paper 1 is also detected by a color sensor 7. The color sensor 7 is installed between the lower protective paper deflection correction machine and the belt conveyor 6, and the detection end of the color sensor 7 faces the front side of the lower protective paper 1. The color sensor 7 is used to detect the printed pattern on the front side of the lower protective paper 1.

The printed pattern is printed on the surface of the lower face paper 1 by a printing roller before passing through the deflection correction machine. Usually, the printed pattern is the manufacturer's name, specification and batch of the gypsum board. Usually, the color sensor 7 is set in the middle of the lower face paper 1, and the sensing color is black.

The controller calculates the linear speed of the lower face paper 1 according to the interval time between two adjacent printed patterns, and then adjusts the transmission speed of the belt conveyor 6 so that the transmission speed of the belt conveyor 6 is equal to the linear speed of the lower face paper 1. There is no relative movement between the transmission surface of the belt conveyor 6 and the lower face paper 1, and no relative friction is generated.

The operator can also use a photoelectric encoder instead of the color sensor 7. The photoelectric encoder is used to detect the rotation speed of the roller that transmits the lower protective paper 1, and then calculate the linear speed of the lower protective paper 1 through the controller. However, this calculation result is not accurate, and there is a problem of slippage between the lower protective paper 1 and the roller.

The above embodiments are only exemplary embodiments of the present invention and are not intended to limit the present invention. The protection scope of the present invention is defined by the claims. Those skilled in the art may make various modifications or equivalent substitutions to the present invention within the essence and protection scope of the present invention, and such modifications or equivalent substitutions shall also be deemed to fall within the protection scope of the present invention.

Claims (10)

1. A method for preparing a hydrophobic film on the surface of a gypsum board is characterized in that,

Comprising the following steps: and (3) smearing an alkali solution mixed with methyl hydrogen silicone oil on the front surface of the lower facing paper, and then drying the wet gypsum board.

2. The method for preparing a hydrophobic film on the surface of a gypsum board according to claim 1, wherein,

And after the lower facing paper passes through the lower facing paper deviation corrector, smearing the alkaline solution on the front surface of the lower facing paper.

3. A method for preparing a hydrophobic film on the surface of a gypsum board according to claim 2, wherein,

The alkaline solution is smeared on the front surface of the lower facing before the lower facing passes through the lower facing scoring machine.

4. A method for preparing a hydrophobic film on the surface of a gypsum board according to claim 3,

And a second lower facial mask paper deviation rectifying machine is added between the lower facial mask paper deviation rectifying machine and the lower facial mask paper scoring machine, and after the alkaline solution is smeared on the front surface of the lower facial mask paper, the lower facial mask paper passes through the second lower facial mask paper deviation rectifying machine.

5. The method for preparing a hydrophobic film on the surface of a gypsum board according to claim 1, wherein,

And a blank area with the width of 10 mm-15 mm is reserved on two sides of the front surface of the lower facing paper, and the alkali solution is smeared at the position outside the blank area.

6. The method for preparing a hydrophobic film on a surface of a gypsum board as claimed in claim 5, wherein,

The step of smearing the alkali solution mixed with the methyl hydrogen silicone oil on the front surface of the lower protective facial tissue comprises the following steps:

spraying the alkali solution on the front surface of the lower facial tissue by using a spray gun;

The alkali solution attached to the front side of the lower facing paper is smoothed out using a spreading member.

7. The method for preparing a hydrophobic film on a surface of a gypsum board as claimed in claim 6, wherein,

The number of the spray guns is a plurality, the spray guns are arranged side by side at equal intervals along the width direction of the lower facing paper, and each spray gun can be independently opened or closed;

The number of the coating parts is at least 2, a plurality of the coating parts form a continuous and uninterrupted coating area in the width direction of the lower facial mask, and the position of at least 1 coating part in the width direction of the lower facial mask can be adjusted to change the whole width of the coating area;

The step of spraying the alkali solution on the front surface of the lower facing paper by using a spray gun comprises the following steps: selectively opening part of the spray gun to enable the alkali solution sprayed by the spray gun on the lower facing paper to avoid a blank area;

The step of trowelling the alkali solution attached to the front side of the lower facer using the applicator member comprises: the position of the coating part is adjusted to change the whole width of the coating area, so that the edge of the coating area is attached to the edge of the blank area.

8. The method for preparing a hydrophobic film on a surface of a gypsum board according to claim 7, wherein,

The step of smearing the alkali solution mixed with the methyl hydrogen silicone oil on the front surface of the lower protective facial tissue further comprises the following steps:

And a supporting component is arranged on one surface of the lower facial tissue facing away from the smearing component, the supporting component comprises a smooth line or surface for supporting the back surface of the lower facial tissue, and the acting force applied on the front surface of the lower facial tissue by the smearing component is counteracted by using the supporting component.

9. The method for preparing a hydrophobic film on a surface of a gypsum board according to claim 7, wherein,

The step of smearing the alkali solution mixed with the methyl hydrogen silicone oil on the front surface of the lower protective facial tissue further comprises the following steps:

And a belt conveyor is arranged on one surface of the lower facial tissues facing away from the smearing part, the transmission surface of the belt conveyor is attached to the back surface of the lower facial tissues, the transmission speed of the belt conveyor is in the same direction and same speed as the linear speed of the lower facial tissues, and the width of the transmission surface of the belt conveyor is larger than that of the lower facial tissues.

10. The method for preparing a hydrophobic film on a surface of a gypsum board according to claim 9, wherein,

The step of smearing the alkali solution mixed with the methyl hydrogen silicone oil on the front surface of the lower protective facial tissue further comprises the following steps:

And detecting the printed patterns on the front surface of the lower facing paper by using a color sensor, calculating the linear speed of the lower facing paper according to the interval time of the occurrence of the adjacent 2 printed patterns, and then adjusting the transmission speed of the belt conveyor so that the transmission speed of the belt conveyor is equal to the linear speed of the lower facing paper.