Preparation process and production formula of high-adhesive gypsum board

Abstract

The invention discloses a preparation process and production formula of a paper-faced gypsum board with high paper adhesion. The dihydrate gypsum is dried to make semi-hydrated gypsum, and water, foaming agent, starch, water reducing agent, coagulant, retarder and glass fiber are added to form slurry; the slurry is pumped into a mixer for stirring; the upper and lower papers are unrolled and enter a molding machine through an automatic deviation correcting machine, and the gypsum slurry in the mixer falls on the lower paper of the vibration platform and enters the molding machine, and a gypsum board is squeezed out on the molding machine; the molded gypsum board is cut into paper-faced gypsum board; dried; packaged and shipped. The formula of the gypsum core board: the amount of water added is based on 68-70% of the standard thickening water; the coagulant is less than 2%; the retarder is a composite retarder of disodium ethylenediaminetetraacetic acid, sodium hexametaphosphate, sodium tripolyphosphate and citric acid; the amount of glass fiber added is 1.5-5%; the amount of foaming agent added is 1.8-4%; the amount of starch used is 0.3-1.25%. The invention greatly improves the dispersibility of the semi-hydrated gypsum, accelerates the hydration heat release rate and shortens the setting time.

Description

Technical Field

[0001] The invention relates to lime, magnesium oxide, slag, cement and a composition thereof, and in particular to a preparation process and a production formula of a high-adhesive paper-faced gypsum board. Background Art

[0002] Shang Yunbao mentioned in the paper "Experimental Study on Improving the Flexural Strength and Adhesion of Gypsum Board" published in "Fertilizer and Health" Volume 48, Issue 3, June 2021: Adhesion refers to the degree of adhesion of the facing paper to the finished gypsum board. It is one of the important indicators in the production process of gypsum board and one of the most intuitive indicators for judging the quality of gypsum board. There are many factors that affect adhesion, mainly the water absorption and air permeability of the facing paper, the amount of starch added, the hydration rate of hemihydrate gypsum, etc. It improves the adhesion of gypsum board by controlling the content and particle size of hemihydrate gypsum, temperature and the amount of accelerator phosphogypsum added.

[0003] Zhang Jiali published a paper titled "The Effect of Melamine Water-Reducing Agent on the Hydration and Hardening Process of α-Hemihydrate Gypsum" in the Journal of Zhejiang University (Science Edition) Vol. 36 No. 3 in May 2009. It mentioned that: SM can accelerate the hydration of α-hemihydrate gypsum. ② The number of dihydrate gypsum crystals in the structure of the gypsum hardened body after modification increases. ② The aspect ratio is significantly reduced. ② The hardened body structure is more compact. Therefore, ② SM can be used to modify α-hemihydrate gypsum. ② It is particularly beneficial to improve the strength of the gypsum hardened body. (Sulfonated melamine (Sulfonated melamine formaldehyde ② SM)). The existing technologies are all from the aspect of component improvement, and the degree of improvement is general. Due to the limitations of their respective preparation processes, they are generally unable to learn from each other. Summary of the invention

[0004] The purpose of the present invention is to overcome the defects existing in the prior art and provide a preparation process of a gypsum board with high paper adhesion, so that the dispersion of hemihydrate gypsum is greatly improved, the agglomeration of hemihydrate gypsum particles is prevented, the contact area between hemihydrate gypsum particles and water is increased, the dissolution of hemihydrate gypsum and the nucleation and crystallization of dihydrate gypsum are accelerated, and thus the hydration heat release rate is accelerated and the setting time is shortened, thereby improving the paper adhesion. By slightly changing the structure of the gypsum board, increasing the specific surface area of ​​the gypsum core board, improving the paper adhesion, combining the improvement of the gypsum board structure with the improvement of the preparation components and process, the ability to improve the paper adhesion is improved.

[0005] To achieve the above object, the technical solution of the present invention is to design a preparation process of a high-adhesive gypsum board, which is composed of the following preparation steps:

[0006] S1: drying dihydrate gypsum to make hemihydrate gypsum, grinding and adding water, foaming agent, starch, water reducing agent, coagulant, retarder and glass fiber to the hemihydrate gypsum to form slurry;

[0007] S2: The slurry is pumped into a mixer and mixed evenly to form gypsum slurry;

[0008] S3: After the upper and lower papers are unwound, they enter the molding machine through the automatic deviation correcting machine. The gypsum slurry in the mixer falls onto the lower paper on the vibrating platform and enters the molding machine, where the gypsum board is squeezed out.

[0009] S4: The formed gypsum board is solidified on the transport track and cut into paper-faced gypsum boards by a cutting machine;

[0010] S5: The cut gypsum boards are sent to a dryer for drying;

[0011] S6: After drying, the gypsum boards are packed and shipped out;

[0012] In the step S1, potassium sulfate is added to water, and the amount added is based on water, and the molar mass is 0.02 mol / 100 g;

[0013] In the step S3, grooves are cut on the paper surface of the face paper facing the gypsum core board; during molding and extrusion on a molding machine, marks are made on the surface of the gypsum core board and corresponding positions on the face paper are polished.

[0014] By slightly changing the structure of the gypsum board, the specific surface area of ​​the gypsum core board is increased and the adhesion is improved.

[0015] Since the air permeability of paper is too low, it will affect the adhesion of gypsum board. During the drying process of gypsum board, starch and excess water will migrate outward. If the air permeability of paper is too low, the density of paper will be relatively large, and starch and excess water will be difficult to escape. They will be concentrated between the face paper and gypsum board, causing the separation of paper and board. Therefore, appropriate micro-grooving of the face paper can improve its air permeability on the one hand, and increase the specific surface area of ​​the face paper and gypsum core board on the other hand to improve the adhesion of paper.

[0016] By improving the facing paper and gypsum core board during the preparation process, the roughness of the corresponding positions of the indentation and expansion facing paper is completed, thereby jointly achieving improved paper adhesion.

[0017] The working principle of starch as an adhesive is to assist the migration of moisture to the surface of the gypsum board and enter the gaps in the facing paper under the action of capillaries, so accelerating the rate of moisture migration and enhancing the migration ability of starch can improve the adhesion of the paper.

[0018] When hemihydrate gypsum is added with water, the surface of the particles comes into contact with water and dissolves uniformly, producing Ca 2+ and SO4 2- . Due to SO42- Volume is larger than Ca 2+ It is much larger and relatively difficult to diffuse outward, so it stays on the surface of the original hemihydrate gypsum particles to form potential ions, while Ca 2+ It quickly enters the liquid phase to form counterions, forming a double-layer structure with a negative zeta potential; the monovalent K + Metal cations can change the zeta potential of gypsum slurry, and the influence is relatively large; cations have opposite electrical properties to hemihydrate gypsum micelles and have electrostatic attraction; increasing the concentration of monovalent cations increases the number of ions entering the double electrical layer, and the zeta potential also increases accordingly; K + It has a great influence on the double electric layer structure, significantly increases the absolute value of the zeta potential, greatly improves the dispersion of hemihydrate gypsum, prevents the agglomeration of hemihydrate gypsum particles, increases the contact area between hemihydrate gypsum particles and water, accelerates the dissolution of hemihydrate gypsum and the nucleation and crystallization of dihydrate gypsum, and thus accelerates the hydration heat release rate and shortens the setting time. As stated in the prior art paper "Experimental Study on Improving the Flexural Strength and Adhesion of Gypsum Board" published by Shang Yunbao in "Fertilizer and Health" in June 2021, Volume 48, Issue 3: The initial setting time and final setting time of hemihydrate gypsum are one of the important factors affecting the adhesion of gypsum board. Generally, the longer the initial setting time and final setting time, the worse the adhesion. Therefore, adding potassium sulfate can improve the adhesion.

[0019] A further technical solution is that in step S1, the dihydrate gypsum is first slurried by adding water before drying; and then 0.2% quicklime is added to the dihydrate gypsum after slurrying.

[0020] The step of adding water to adjust the slurry is as follows: adding water to the phosphogypsum so that the mass fraction of the dihydrate gypsum after the water adjustment is controlled to be 60%, stirring for 20 to 30 minutes and then filtering.

[0021] The mass fraction of dihydrate gypsum after water slurrying is controlled to be 60%. Adding 0.2% quicklime to the dihydrate gypsum after water slurrying can improve the pH value of dihydrate gypsum, shorten the initial setting and final setting time in the production process; and improve the adhesion (because the initial setting time and final setting time of hemihydrate gypsum are one of the important factors affecting the adhesion of paper-faced gypsum board. Generally, the longer the initial setting time and final setting time, the worse the adhesion, and the flexural strength will also be affected to a certain extent).

[0022] A further technical solution is that in step S1, the drying temperature of dihydrate gypsum is 150°C; the accelerator is dihydrate gypsum, and the dosage is less than 2%; the drying time is 60 to 70 minutes; the amount of water added is based on 68 to 70% of the standard thickening water; the grinding time is 20 to 30 seconds; the amount of starch is 1.2 to 1.5%; the retarder is a composite retarder of disodium ethylenediaminetetraacetic acid, sodium hexametaphosphate, sodium tripolyphosphate and citric acid, wherein disodium ethylenediaminetetraacetic acid and sodium hexametaphosphate are used. , sodium tripolyphosphate, and citric acid are added in amounts of 0.30%, 0.15%, 0.15%, and 0.15%, respectively; glass fiber is 1.5-5%; the foaming agent is calcium lignin sulfonate or sodium α-olefin sulfonate, and the addition amount is 0.01-0.1%; the water reducer is at least one of a polycarboxylic acid high-performance water reducer and a naphthalene-based water reducer, and the amount of the water reducer is 0.125-1.2%; the starch is modified cassava starch PB916, and the amount is 0.3-1.25%;

[0023] In the step S3, the ambient temperature of the extrusion molding is maintained at 40°C.

[0024] The technical scheme disclosed in the present invention is a production formula of a high-adhesive paper-faced gypsum board, which is composed of a gypsum core board and upper and lower protective papers; wherein the formula of the gypsum core board is as follows: the amount of water added is based on 68-70% of the standard thickening water; the coagulant is less than 2%; the composition ratio of the components in the component after the dihydrate gypsum is dried to form the semi-hydrate gypsum is: the mass fraction of the semi-hydrate gypsum is ≥65.00%, and the mass fraction of the dihydrate gypsum is ≤4.90%; the retarder is disodium ethylenediaminetetraacetic acid, sodium hexametaphosphate, tripolyphosphate The invention discloses a compound retarder of sodium bisulphate and citric acid, wherein the addition amounts of disodium ethylenediaminetetraacetate, sodium hexametaphosphate, sodium tripolyphosphate and citric acid are 0.30%, 0.15%, 0.15% and 0.15% respectively; the addition amount of glass fiber is 1.5-5%, the diameter of glass fiber is 0.01-0.013mm, and the length is 10-15mm; the foaming agent is calcium lignin sulfonate, and the addition amount is 1.8-4%; the starch is modified cassava starch PB916, and the usage amount is 0.3-1.25%.

[0025] The advantages and beneficial effects of the present invention are that the improvement of the structure of the gypsum board is combined with the improvement of the preparation components and the process, so that the ability to improve the paper adhesion is improved.

[0026] By slightly changing the structure of the gypsum board, the specific surface area of ​​the gypsum core board is increased and the adhesion is improved.

[0027] Since the air permeability of paper is too low, it will affect the adhesion of gypsum board. During the drying process of gypsum board, starch and excess water will migrate outward. If the air permeability of paper is too low, the density of paper will be relatively large, and starch and excess water will be difficult to escape. They will be concentrated between the face paper and gypsum board, causing the separation of paper and board. Therefore, appropriate micro-grooving of the face paper can improve its air permeability on the one hand, and increase the specific surface area of ​​the face paper and gypsum core board on the other hand to improve the adhesion of paper.

[0028] By improving the facing paper and gypsum core board during the preparation process, the roughness of the corresponding positions of the indentation and expansion facing paper is completed, thereby jointly achieving improved paper adhesion.

[0029] The working principle of starch as an adhesive is to assist the migration of moisture to the surface of the gypsum board and enter the gaps in the facing paper under the action of capillaries, so accelerating the rate of moisture migration and enhancing the migration ability of starch can improve the adhesion of the paper.

[0030] After adding water to the semi-hydrated gypsum, the surface of the particles comes into contact with water, dissolving uniformly and producing Ca2+ and SO42-. Since SO42- is much larger in volume than Ca2+ and is relatively difficult to diffuse outward, it is retained on the surface of the original semi-hydrated gypsum particles to form potential ions, while Ca2+ quickly enters the liquid phase to form counterions, forming a double-layer structure with a negative zeta potential; monovalent K+ metal cations can change the zeta potential of the gypsum slurry, and the influence is relatively large; cations have opposite electrical properties to the semi-hydrated gypsum micelles and have an electrostatic attraction; increasing the concentration of monovalent cations increases the number of ions entering the double layer, and the zeta potential also increases accordingly; K+ has a greater influence on the double layer structure, significantly increasing the absolute value of the zeta potential, greatly improving the dispersion of the semi-hydrated gypsum, preventing the agglomeration of the semi-hydrated gypsum particles, increasing the contact area between the semi-hydrated gypsum particles and water, accelerating the dissolution of the semi-hydrated gypsum and the nucleation and crystallization of the dihydrated gypsum, and therefore accelerating the hydration heat release rate and shortening the setting time. As stated in the paper "Experimental Study on Improving the Flexural Strength and Adhesion of Gypsum Board" published by Shang Yunbao in the Journal of Fertilizer and Health, Vol. 48, No. 3, June 2021, the initial setting time and final setting time of hemihydrate gypsum are one of the important factors affecting the adhesion of gypsum board. Generally, the longer the initial setting time and final setting time, the worse the adhesion. Therefore, adding potassium sulfate can improve the adhesion.

[0031] The mass fraction of dihydrate gypsum after water slurrying is controlled to be 60%. Adding 0.2% quicklime to the dihydrate gypsum after water slurrying can improve the pH value of dihydrate gypsum, shorten the initial setting and final setting time in the production process; and improve the adhesion (because the initial setting time and final setting time of hemihydrate gypsum are one of the important factors affecting the adhesion of paper-faced gypsum board. Generally, the longer the initial setting time and final setting time, the worse the adhesion, and the flexural strength will also be affected to a certain extent). BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 It is a schematic diagram of a molding machine, a solidifying belt and a conveying roller in Example 1 of a preparation process of a high-adhesive gypsum board of the present invention;

[0033] Figure 2 yes Figure 1 A three-dimensional schematic diagram of the middle forming machine;

[0034] Figure 3 yes Figure 1 Top view of the solidification belt;

[0035] Figure 4 yes Figure 1 Side view of the mid-solidification belt;

[0036] Figure 5 yes Figure 4 An enlarged schematic diagram of the middle pressure roller part;

[0037] Figure 6 yes Figure 1 A top view of the middle conveyor roller;

[0038] Figure 7 is a schematic diagram of Embodiment 3 of the present invention;

[0039] Figure 8 yes Figure 7 Schematic diagram of the solidification belt;

[0040] Fig. 9 yes Figure 7 A top view of the first solidification belt conveyor mechanism;

[0041] Fig.10 yes Figure 7 Schematic diagram of the first solidification belt conveyor mechanism;

[0042] Fig.11 yes Fig.10 A magnified schematic diagram of part A;

[0043] Fig.12 yes Fig.10 Schematic diagram of the paper-faced gypsum board and the pressboard;

[0044] Fig.13 yes Fig.10 Side view of

[0045] Fig.14 yes Fig.10 Schematic diagram of the cam mechanism after action;

[0046] Fig.15 yes Fig.14 A magnified schematic diagram of part B;

[0047] Fig.16 yes Fig.11 Schematic diagram of the cam mechanism;

[0048] Fig.17 yes Fig.16 Side view of

[0049] Fig.18 is a schematic diagram of a fourth embodiment of the present invention;

[0050] Fig.19 yes Fig.18 Side view of

[0051] Fig. 20 yes Fig.19 Schematic diagram of the state when the worker operates to the halfway position;

[0052] Fig.21 yes Fig.19 Schematic diagram of the state when the worker operates to the final position;

[0053] Fig. 22 yes Fig.21 An enlarged schematic diagram of the middle oval portion;

[0054] Fig.23 yes Fig.19 Top view of the .

[0055] In the figure: 1, forming machine; 2, solidification belt; 3, conveying roller; 4, pressure roller; 5, baffle; 6, first solidification belt conveying mechanism; 7, pressure plate; 8, rubber elastic strip; 9, paper-faced gypsum board; 10, push rod; 11, bending rod; 12, compression spring; 13, limit bending rod; 14, photoelectric sensor; 15, bottom plate; 16, cam; 17, servo motor; 18, intermediate wheel; 19, roller; 20, channel; 21, baffle; 22, connecting rope; 23, weight block; 24, sliding channel; 25, reduction motor; 26, friction wheel; 27, seat plate. DETAILED DESCRIPTION

[0056] The specific implementation of the present invention is further described below in conjunction with the accompanying drawings and embodiments. The following embodiments are only used to more clearly illustrate the technical solution of the present invention, and cannot be used to limit the protection scope of the present invention.

[0057] Embodiment 1: Figures 1 to 6As shown, the present invention is a preparation process of a high-adhesive paper-faced gypsum board, wherein dihydrate gypsum (phosphogypsum) is roasted to prepare semi-hydrated gypsum, and then a proper amount of water is added to the semi-hydrated gypsum (in order to reduce the weight of the finished gypsum board, a proper amount of foaming agent, starch, etc. are added at the same time) to form a slurry; potassium sulfate is added to the water, and the added amount is based on water, and the molar mass is 0.02 mol / 100g; before the dihydrate gypsum is dried, the dihydrate gypsum is firstly treated by adding water to the slurry; then 0.2% quicklime is added to the dihydrate gypsum after the water-added slurry;

[0058] The step of adding water to adjust the slurry is as follows: adding water to the phosphogypsum so that the mass fraction of the dihydrate gypsum after adding water to adjust the slurry is controlled to 60%, stirring for 20 to 30 minutes and then filtering.

[0059] All the slurry is pumped into the mixer and mixed evenly to form qualified gypsum slurry;

[0060] After unwinding, the upper and lower papers are passed through an automatic deviation correcting machine (the upper and lower papers enter the molding machine after being polished and grooved), and the slurry from the mixer falls onto the lower paper on the vibrating platform and enters the molding machine 1, where gypsum boards of different specifications are extruded; grooves are cut on the paper surface of the face paper facing the gypsum core board (i.e., the lower paper surface of the upper paper and the upper paper surface of the lower paper) (the face paper is grooved by a groover); during molding and extrusion on the molding machine, marks are made on the surface of the gypsum core board and the corresponding position of the face paper is polished (the face paper is polished first by a grinder, and the polished and grooved face paper is then entered into the molding machine; or when the upper paper is pressed against the gypsum slurry, the timing of the grinding by the grinder is calculated according to the transmission speed of the upper paper, and a small handheld grinder / grinder is moved close to the upper paper and polished at the required position and then immediately leaves the lower paper surface of the upper paper).

[0061] After the gypsum board of required specifications is extruded on the molding machine 1, the initial setting is completed on the solidification belt 2, the final setting is completed on the conveying roller 3, and the board is cut into the required length by the fixed-length cutting machine. Therefore, the aforementioned processing step of indenting the surface of the gypsum core board during molding and extrusion on the molding machine 1 is actually indenting in the initial setting stage (using the pressing roller 4 set above the solidification belt 2 to form an indentation on the paper-faced gypsum board; the pressing roller 4 is rotatably set on the side baffle 5 of the solidification belt 2) to form the desired stable indentation effect (the indentation here is different from the well-known in the art of indenting or scoring the paper under the face paper or using a pressing wheel to press out a line mark to form the covering paper of the height edge of the gypsum board; here, a dent is pressed on the surface of the gypsum board). Since there is a slightly downward dent on one surface of the paper-faced gypsum board after indentation, this surface is generally used as the inner layer of the building to avoid affecting the appearance (so compared with the prior art, the creasing wheel in this embodiment first releases a portion of the amount when pressing the creasing marks on both sides of the paper to facilitate the need for the upper paper to be sunken into the indentation required for the subsequent pressing roller indentation process, that is, compared with the prior art, the spacing between the two sides of the line marks pressed by the creasing wheel in this embodiment is slightly larger than the width of the gypsum core board, and the extra part is used to allow the facing paper to be sunken into the indentation formed by the indentation).

[0062] The formed gypsum board is solidified on the conveyor roller 3 and cut into different sizes by the cutting machine;

[0063] The cut gypsum boards enter the dryer for drying;

[0064] After drying, the gypsum board can be packaged for use.

[0065] The drying temperature of dihydrate gypsum is 150°C; the accelerator is dihydrate gypsum, and the dosage is less than 2%; the drying time is 60 to 70 minutes; the amount of water added is based on 68 to 70% of the standard thickening water; the grinding time is 20 to 30 seconds; the starch dosage is 1.2 to 1.5%; the retarder is a composite retarder of disodium ethylenediaminetetraacetic acid, sodium hexametaphosphate, sodium tripolyphosphate and citric acid, wherein disodium ethylenediaminetetraacetic acid, sodium hexametaphosphate, sodium tripolyphosphate, citric acid The amount of acid added is 0.30%, 0.15%, 0.15% and 0.15% respectively; the glass fiber is 1.5-5%; the foaming agent is calcium lignin sulfonate or sodium α-olefin sulfonate, and the addition amount is 0.01-0.1%; the water reducer is at least one of polycarboxylic acid high-performance water reducer and naphthalene series water reducer, and the amount of water reducer is 0.125-1.2%; the starch is modified cassava starch PB916, and the amount is 0.3-1.25%;

[0066] The ambient temperature for extrusion molding was maintained at 40°C.

[0067] Embodiment 2: The difference from Embodiment 1 is that the preparation process of "drying dihydrate gypsum to prepare semi-hydrate gypsum" in step S1 is different, namely: drying dihydrate gypsum twice to prepare semi-hydrate gypsum; taking out part of the semi-hydrated components after the first drying; drying the remaining components for the second time, and then adding water, foaming agent, starch, water reducing agent, components after the first drying (the components are semi-hydrate gypsum and dihydrate gypsum; and dihydrate gypsum can also be used as a coagulant), and retarder to the semi-hydrate gypsum to form a slurry;

[0068] The coagulant is still dihydrate gypsum; therefore, in the process of drying dihydrate gypsum to make semi-hydrate gypsum, a part of the semi-dried components (that is, containing a part of dihydrate gypsum and semi-hydrate gypsum) are leaked out in an extensive manner and directly added into the system as a coagulant, thereby reducing the content of free water in the dihydrate gypsum used as a coagulant, which is more in line with the actual process requirements.

[0069] This method is convenient for controlling the content of the coagulant used as dihydrate gypsum and avoiding excessive addition of the coagulant. Taking out some components also reduces the amount of objects to be dried for the second time, so the increase in energy consumption is not large; therefore, although the use of two dryings increases energy consumption to a certain extent, it is convenient for producing hemihydrate gypsum and the increase in energy consumption is not large, so it is still a technical improvement worth promoting.

[0070] Moreover, this method can reduce the temperature control requirements of the first drying. It only needs to use a lower temperature and a shorter time than the first drying temperature to carry out preliminary drying of the dihydrate gypsum in a rough manner, which reduces the stringency of the process requirements. The requirements for technical workers or equipment are reduced; because the method of drying twice in sequence is adopted, in case the process parameters of the first drying are inappropriate, they can be adjusted by the second drying (after the first drying, the moisture and other related parameters of the remaining components mentioned above are tested, and the process parameters of the second drying are formulated according to the situation of the remaining components mentioned above), which can reduce the situation where defective products caused by the first drying cannot be remedied (because the preparation of semi-hydrated gypsum from dihydrate gypsum has the process requirements of controlling the drying temperature and time to avoid excessive temperature causing changes in the quality of gypsum, so the use of two dryings and the use of a shorter time and lower temperature in the first drying can better avoid the above situation compared with the method of drying once, so this embodiment can better produce semi-hydrated gypsum).

[0071] Embodiment 3: The difference from Embodiment 1 is that Figures 7 to 17 As shown (for ease of illustration, Figures 7 to 9 The cam mechanism is not shown in the figure), and during the extrusion molding process, an elastic element arranged on the lower surface of the upper paper forms a preliminary indentation on the surface of the unsolidified gypsum slurry (i.e., the gypsum slurry on the lower paper) during the extrusion molding process;

[0072] In this way, an indentation can be formed during extrusion; and during extrusion, a small handheld grinder / grinding machine is used to approach the upper paper and grind at the required position, and then the lower paper surface of the upper paper is immediately removed; so grinding and indentation can be completed at the same time in the extrusion process; no additional process is required, which reduces the complexity of the process, reduces working hours, and improves work efficiency. Therefore, the three processes of indenting the surface of the gypsum core board, grinding the face paper, and grooving are equivalent to adding only one grooving process to the entire process, that is, the face paper is grooved before extrusion, and then the gypsum core board is polished and indented during the extrusion process (of course, to be more precise, an indentation is initially formed on the surface of the gypsum slurry during extrusion).

[0073] A pressing plate 7 is arranged on the first solidification belt conveying mechanism 6, and a pressing roller 4 is arranged on the solidification belt 2 (the pressing roller 4 is used to press the upper paper of the face paper downward so that the upper paper abuts against the indentation of the gypsum core board); an intermittent pushing mechanism for partially pushing the rubber elastic strip out of the paper-faced gypsum board is also arranged between the pressing plate and the pressing roller, and the intermittent pushing mechanism is used to push the rubber elastic strip 8 placed between the upper paper and the gypsum slurry out of a part of the paper-faced gypsum board 9. The intermittent pushing mechanism is arranged at the starting end of the conveying direction of the first solidification belt conveying mechanism 6. The intermittent pushing mechanism includes a cam mechanism fixedly arranged on the pressure plate 7 and a bent rod 11 located on one side of the push rod 10 of the cam mechanism. The bent rod is hinged at the end of the pressure plate 7, and the bent rod is connected to a compression spring 12. The other end of the compression spring is fixedly connected to the pressure plate 7. The size and shape of the bent rod 11 meet the requirements that when the cam mechanism is actuated, the push rod 10 pushes the bent rod to rotate and overcomes the elastic force of the compression spring 12 to push against the rubber elastic strip 8. In order to prevent the bent rod from being pushed by the push rod to rotate too much, a limiting bent rod 13 fixedly connected to the side end face of the pressure plate 7 is arranged below the hinge between the bent rod 11 and the pressure plate 7. A photoelectric sensor 14 is arranged above the end of the conveying direction of the first solidification belt conveyor mechanism. The photoelectric sensor is connected to the signal of a controller remotely arranged on the first solidification belt conveyor mechanism, and the controller is connected to the signal of a servo motor on the cam mechanism. The cam mechanism also includes a base plate 15, on which a cam 16 is rotatably arranged. One side of the base plate A cam is set on one side, and a servo motor 17 is set on the other side. The output shaft of the servo motor 17 is fixedly connected to the wheel axle of the cam 16. The bottom plate is connected to the pressure plate 7 through a connecting rod. A push rod is also slidably set on the bottom plate. An intermediate wheel 18 is rotatably set at the end of the push rod, and the intermediate wheel 18 is set against the cam 16; when the photoelectric sensor receives a signal, the controller controls the servo motor to operate, and the push rod slides outward to push the bent rod, and the bent rod overcomes the elastic force of the compression spring and rotates toward the gypsum board. Due to the position setting and the shape of the bent rod, the bent rod is rotated until it abuts against the limit bent rod 13, which just pushes the rubber elastic strip 8. Since the gypsum board is in a state of being transported by the first solidifying belt conveyor mechanism, the speed of the servo motor and the selection of the compression spring should be such that when the push rod of the cam mechanism pushes the rear bent rod to abut against the rubber elastic strip, the component speed of the bent rod along the horizontal direction is greater than the conveying speed of the first solidifying belt conveyor mechanism.Therefore, the process is to place the rubber elastic strip 8 on the slurry surface of the gypsum slurry before extrusion, and then the pressure plate 7 presses the upper paper during the conveying of the first solidifying belt conveyor mechanism 6 to prevent the rubber elastic strip from squeezing the upper paper of the facing paper upward due to its elasticity and the initial setting of the gypsum slurry, making the upper paper part convex. When the first solidifying belt conveyor mechanism conveys the gypsum board to the end of the first solidifying belt conveyor mechanism, the controller controls the servo motor to move, and the bending rod is pushed by the push rod of the cam mechanism to rotate. This process of the bending rod rotation realizes the pushing of the rubber elastic strip to push a certain length of the gypsum board, and the end of the pushed rubber elastic strip continues to be pulled out manually. Then the gypsum board is conveyed to the solidifying belt 2, and the pressure roller 4 (the height of the lower horizontal plane tangent to the pressure roller is slightly lower than the height of the upper paper of the gypsum board, so that the upper paper of the facing paper can be pressed down) presses the upper paper of the facing paper to the space after the rubber elastic strip is pulled out.

[0074] In the initial setting stage (in the present embodiment, it is at the first solidification belt conveyor mechanism; because in the present embodiment, the initial setting stage is divided into two parts, that is, the initial setting is realized on the first solidification belt conveyor mechanism 6 and the solidification belt 2), a pressing plate is arranged, and the pressing plate is fixedly connected to the frame of the first solidification belt conveyor mechanism, and a roller 19 is rotatably arranged under the pressing plate, and the roller abuts against the paper-faced gypsum board, so that the elastic element located on the lower surface of the upper paper during extrusion (the elastic element adopts a rubber elastic strip arranged on the lower surface of the upper paper, and the rubber elastic strip is hollow, that is, a cavity is arranged in the middle of the rubber elastic strip so that the rubber elastic strip can float on the gypsum slurry when it is placed and arranged between the upper paper and the gypsum slurry; the rubber elastic strip is before extrusion, that is, before the upper paper enters the forming machine It is placed on the slurry surface of the gypsum slurry. The placement position is determined by the position of the pressure roller subsequently arranged above the solidifying belt 2, that is, the placement position is consistent with the position of the pressure roller 4 arranged above the solidifying belt 2, to ensure that when the pressure roller 4 subsequently presses down the upper paper of the face paper, it is pressed on the space after the rubber elastic strip is pulled out). The upper paper of the face paper will not be squeezed upward due to the elasticity and the initial setting of the gypsum slurry, making the upper paper part convex (and this process can also make the initial indentation form. Even if the rubber elastic strip is pushed out later, the indentation on the surface of the gypsum core board still exists. Because this process takes a period of time to make the gypsum slurry slightly solidified, there will be no resistance to the subsequent immediate push out and manual removal of the rubber elastic strip, but the initially formed indentation still exists). A pre-solidification belt conveyor mechanism is arranged in front of the solidification belt (actually the solidification belt conveyor mechanism), and the sum of the lengths of the solidification belt conveyor mechanism and the pre-solidification belt conveyor mechanism in this embodiment is consistent with the length of the solidification belt conveyor mechanism in the prior art to ensure that the desired solidification state in the initial setting stage is achieved (in order to seal the slurry between the upper paper and the lower paper, the process of folding the gypsum board along the line mark is arranged after the pressing roller is completed).

[0075] Embodiment 4: The difference from Embodiment 3 is that Figures 18 to 23As shown in the figure (in the figure, the connecting rope passes through the side plate of the first solidifying belt conveyor mechanism 6 and then is turned by the fixed pulley arranged outside the side plate; for the convenience of illustration, it is not shown in the figure), a channel 20 for people to reach in is respectively arranged on the side plates on both sides of the first solidifying belt conveyor mechanism 6, and the two channels 20 are inclined along the conveying direction from the side plate to the center direction of the first solidifying belt conveyor mechanism 6 (to be more in line with the conveying and discharging direction), and a baffle 21 is slidably arranged on the inner top wall of the channel 20, and the baffle 21 is used to block the driving mechanism that drives the rubber elastic strip 8 to leave the paper-faced gypsum board and arrive at the two sides of the rubber elastic strip asynchronously, and the two baffles 21 are connected to the same weight block 23 through a connecting rope 22; the weight The block 23 slides vertically on the sliding channel 24, which is fixedly connected to the frame of the first solidification belt conveyor 6, so that the hands (more specifically, the driving mechanism operated by the hands) extending from the two channels 20 can reach the rubber elastic strip 8 synchronously; the driving mechanism includes a reduction motor 25, a friction wheel 26 fixedly connected to the output shaft of the reduction motor, and the reduction motor is fixedly connected to the seat plate 27; the worker holds the seat plate 27 against the baffle 21, and when the baffle 21 reaches the end of the channel 20, that is, close to one end of the rubber elastic strip 8, the friction wheel 26 just abuts against the side of the rubber elastic strip 8, and the friction wheel rotates to drive the rubber elastic strip 8 to move outward quickly and detach from the paper-faced gypsum board. In order to better implement this solution, the paper-faced gypsum board needs to stop when it reaches the conveying end of the first solidification belt conveyor 6 to facilitate the worker's operation.

[0076] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the technical principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A process for preparing a high-adhesive gypsum board, characterized in that: It consists of the following preparation steps: S1: drying dihydrate gypsum to make hemihydrate gypsum, grinding and adding water, foaming agent, starch, water reducing agent, coagulant, retarder and glass fiber to the hemihydrate gypsum to form slurry; S2: The slurry is pumped into a mixer and mixed evenly to form gypsum slurry; S3: After the upper and lower papers are unwound, they enter the molding machine through the automatic deviation correcting machine. The gypsum slurry in the mixer falls onto the lower paper on the vibrating platform and enters the molding machine, where the gypsum board is squeezed out. S4: The formed gypsum board is solidified on the transport track and cut into paper-faced gypsum boards by a cutting machine; S5: The cut gypsum boards are sent to a dryer for drying; S6: After drying, the gypsum boards are packed and shipped out; In the step S1, potassium sulfate is added to water, and the amount added is based on water, and the molar mass is 0.02 mol / 100 g; In the step S3, grooves are made on the paper surface of the face paper facing the gypsum core board; during the molding and extrusion on the molding machine, marks are made on the surface of the gypsum core board and the corresponding position of the face paper is polished; The process of "drying dihydrate gypsum to form semi-hydrate gypsum" in step S1 is as follows: drying dihydrate gypsum twice to form semi-hydrate gypsum; taking out part of the semi-hydrated components after the first drying; drying the remaining components for the second time, and adding the components after the first drying to the semi-hydrated gypsum; The pressing roller arranged above the solidifying belt is used to form an indentation on the paper-faced gypsum board; the pressing roller is rotatably arranged on the side baffle of the solidifying belt.

2. The process for preparing a high-adhesive gypsum board according to claim 1, characterized in that: In the step S1, the dihydrate gypsum is first hydrated and slurried before being dried; then 0.2% quicklime is added to the slurry-mixed dihydrate gypsum; The step of adding water to adjust the slurry is as follows: adding water to the phosphogypsum so that the mass fraction of the dihydrate gypsum after the water adjustment is controlled to be 60%, stirring for 20 to 30 minutes and then filtering.

3. The process for preparing a high-adhesive gypsum board according to claim 2, characterized in that: In the step S1, the drying temperature of dihydrate gypsum is 150°C; the accelerator is dihydrate gypsum, and the dosage is less than 2%; the drying time is 60-70 minutes; the amount of water added is based on 68-70% of the standard thickening water; the grinding time is 20-30 seconds; the starch dosage is 1.2-1.5%; the retarder is a composite retarder of disodium ethylenediaminetetraacetic acid, sodium hexametaphosphate, sodium tripolyphosphate and citric acid, wherein disodium ethylenediaminetetraacetic acid, sodium hexametaphosphate, sodium tripolyphosphate and citric acid are used. The addition amount of sodium sulfonate and citric acid is 0.30%, 0.15%, 0.15% and 0.15% respectively; the glass fiber is 1.5~5%; the foaming agent is calcium lignin sulfonate or sodium α-olefin sulfonate, and the addition amount is 0.01~0.1%; the water reducer is at least one of polycarboxylic acid high-performance water reducer and naphthalene series water reducer, and the water reducer dosage is 0.125~1.2%; the starch is modified cassava starch PB916, and the dosage is 0.3~1.25%; In the step S3, the ambient temperature of the extrusion molding is maintained at 40°C.

Images