A foaming agent mixed solution, a gypsum slurry, a gypsum board and processes for preparing the gypsum slurry and for fabricating the gypsum board
Patent Information
- Authority / Receiving Office
- EP · EP
- Patent Type
- Applications
- Current Assignee / Owner
- SAINT GOBAIN PLACO SAS
- Filing Date
- 2024-10-31
- Publication Date
- 2026-06-03
AI Technical Summary
Existing gypsum boards have an uneven distribution of air hole diameters in their board cores, leading to inconsistent performance and increased water absorption.
A foaming agent mixed solution comprising an unstable foaming agent and a foam stabilizer, such as sodium alpha-olefin sulfonate, is used to create a gypsum slurry with a controlled air hole distribution, resulting in a more uniform board core with reduced water absorption.
The solution achieves a more uniform distribution of air hole diameters in the gypsum board core, reducing water absorption to no more than 25% and enhancing the overall performance of the gypsum board.
Smart Images
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Abstract
Description
[0001] A foaming agent mixed solution, a gypsum slurry, a gypsum board and processes for preparing the gypsum slurry and for fabricating the gypsum board
[0002] Technical Field
[0003] The present disclosure relates to the field of building materials, and particularly to a foaming agent mixed solution for preparing a gypsum board, a gypsum based slurry comprising the foaming agent mixed solution and a gypsum board formed from the slurry.
[0004] Background
[0005] Gypsum board is commonly used in building. Generally, the gypsum board is constituted from a board core formed by a gypsum slurry with a surface-protecting paper attached thereto. The gypsum slurry is formed by mixing a calcined gypsum, water and an additive.
[0006] To reduce the weight of the gypsum board, a foaming agent is usually added to the gypsum slurry to form bubbles therein. This results in the formation of the board core with a large number of air holes, thereby reducing the weight of the gypsum board.
[0007] However, due to uncontrolled formation of bubbles, the distribution range of diameters of the air holes eventually formed in the board core is relatively large. The industrial goal is to create air holes with even distribution and diameters in the board core.
[0008] Summary
[0009] Accordingly, an object of the present disclosure is to improve the diameter distribution of air holes in the board core of the gypsum board, thereby enhancing the performance of the gypsum board.
[0010] In an aspect, provided is a foaming agent mixed solution, comprising an unstable foaming agent and a foam stabilizer. In an embodiment, the foam stabilizer is 3-50% of the total mass of the foaming agent mixed solution. In an embodiment, the foam stabilizer is a sodium alphaolefin sulfonate solution.
[0011] In another aspect, provided is a gypsum slurry, comprising the following components, on a mass basis, 100 parts of a calcined gypsum; 0.2-5 parts of a starch; and 0.03-0.20 parts of the foaming agent mixed solution as described above.
[0012] In an embodiment, the gypsum slurry further comprises, 0.1-0.5 parts of a water reducing agent; 0.1-1 parts of a coagulant; 0.1-1 parts of a retarder; and 50-70 parts of water.
[0013] In yet another aspect, provided is a gypsum board, comprising a board core formed from the gypsum slurry as described above with air holes in the board core, wherein the deviation value of diameters of the air holes is no more than 1.2, preferably no more than 1.0. In an embodiment, the water absorption of the board core is no more than 25%.
[0014] In yet another aspect, provided is a process for preparing the gypsum slurry as described above, comprising the following steps: Step 100, adding a solution of a foam stabilizer into a solution of an unstable foaming agent to give a foaming agent mixed solution; Step 200, mixing the foaming agent mixed solution with water and injecting a gas for foaming, to give a second mixed solution; Step 300, mixing the second mixed solution with a calcined gypsum, water, a starch, a reducing agent, a coagulant and a retarder with stirring for homogenization.
[0015] In yet another aspect, provided is a process for fabricating the gypsum board as described above, comprising the following steps: Step 10, providing a first surface-protecting layer; Step 20, placing the gypsum slurry on the first surface-protecting layer to give a slurry layer, wherein the gypsum slurry is prepared by the process for preparing the gypsum slurry as described above; Step 30, providing a second surface-protecting layer on the slurry layer to give a wet board body; Step 40, drying the wet board body. In an embodiment, the process further comprises forming a priming coating layer on a side of the first surface-protecting layer and / or the second surface-protecting layer towards the slurry.
[0016] The technical solutions as provided herein make sizes of the air holes in the formed gypsum board more uniform and can control the size distribution of the air holes to a certain extent. The technical solutions as provided herein also reduce the water absorption of the formed gypsum board.
[0017] Brief Description of the Drawings
[0018] Fig. 1 shows an image of the board core of a gypsum board obtained using a prior art foaming agent solution.
[0019] Fig. 2 shows an image of the board core of the gypsum board of Example 10.
[0020] Fig. 3 shows an image of the board core of the gypsum board of Example 6.
[0021] Examples
[0022] The specific embodiments of the present disclosure will be described in detail below, which are only used to illustrate the present disclosure rather than limitation thereto.
[0023] According to an embodiment according to the present disclosure, provided is a foaming agent mixed solution, comprising an unstable foaming agent and a foam stabilizer. The unstable foaming agent may be any suitable known product and may be commercially available.
[0024] The foam stabilizer may be a sodium alpha-olefin sulfonate solution, for example, an aqueous solution. It may be commercially available. Depending on different products, the concentration range of sodium alpha-olefin sulfonate is usually 30-35% by mass.
[0025] The foam stabilizer is 3-50% of the total mass of the foaming agent mixed solution, depending on the concentration of the sodium alpha-olefin sulfonate solution and the desired diameters of the air holes in the final product.
[0026] The present inventors have found that with other process parameters unchanged, the proportion of the foam stabilizer is negatively correlated with the diameters of air holes in the final resulting gypsum board core. That is, the higher the proportion of the foam stabilizer, the smaller the air hole diameters of the final resulting gypsum board core. When the proportion of foam stabilizer exceeds 50%, the air holes in the gyro board core are overly small to effectively reduce the weight of the gyro board. When the proportion of foam stabilizer is less than 3%, the final resulting gypsum board core may have defects. Accordingly, as compared to the situation where a foam stabilizer is not used, the technical solution of the present application can reduce air hole defects in the gypsum board, such as multiple air hole fusion or connection.
[0027] In another embodiment according to the present disclosure, provided is a gypsum slurry, comprising the following components, on a mass basis, 100 parts of a calcined gypsum; 0.2-5 parts of a starch; 0.03-0.20 parts of the foaming agent mixed solution as described above, 0.1- 0.5 parts of a water reducing agent; 0.1-1 parts of a coagulant; 0.1-1 parts of a retarder; and 50- 70 parts of water.
[0028] The content of the foaming agent mixed solution as used may be determined according to specific applications. When the content of the foaming agent mixed solution is low, due to decrease of the foaming agent, the bubble walls become thinner and burst, resulting in less air remaining in the slurry and a decrease in foaming efficiency. When the content of the foaming agent mixed solution increases, the bubbles become stable and have smaller diameters, but excessive foaming agent cannot further improve foaming efficiency. The foaming efficiency herein refers to the density ratio of gypsum slurry to water. The lower the density ratio, the higher the foaming efficiency. As compared to prior foaming agent, the foaming agent mixed solution with foam stabilizer added according to the present disclosure can increase the foaming efficiency by about 5%.
[0029] The water reducing agents, coagulant, and retarder may be any suitable commercially available products, and their specific contents may be determined by those skilled in the art based on practical applications. As used herein, the contents of water reducing agent, coagulant, water and retarder are those conventionally used in the field.
[0030] In another embodiment according to the present disclosure, provided is a gypsum board, comprising a board core formed from the gypsum slurry as described above with air holes in the board core, wherein the deviation value of diameters of the air holes is no more than 1.2, preferably no more than 1.0.
[0031] The method for determining the deviation value of air hole diameters is as follows.
[0032] Obtaining an image of cross-section of the board core using any suitable camera device.
[0033] Identifying diameters and areas of air holes in the image using a software, which may be commercially available. The air hole diameters DIO, D50, and D90 are determined. DIO refers to the air hole diameter corresponding to the distribution where the air hole diameters reach 10%, and its physical meaning is that 10% of air holes have diameters smaller than DIO. Similarly, D50 refers to the air hole diameter corresponding to the distribution where the air hole diameters reach 50%, and its physical meaning is that 50% of air holes have diameters smaller than D50 and 50% of air holes also have diameters larger than D50. D90 refers to the air hole diameter corresponding to the distribution where the air hole diameters reach 90% and its physical meaning is that 90% of air holes have diameters smaller than D90. That is, D50 is the median value of the air hole diameter distribution.
[0034] Obtaining the deviation value, also known as span (SPAN), using the following formula 1. SPAN=(D90-D10) / D50 Formula 1
[0035] The smaller the deviation value as obtained, that is, the closer the span is to 0, the more uniform and consistent the size of the air holes.
[0036] Furthermore, due to the use of the foam stabilizer, more closed air holes are generated, resulting in a decrease in water absorption of the board core. As determined with the method stipulated in the National Standard GB / T9775-2008 for Gypsum Boards, the water absorption of the board core of the gypsum board of the present disclosure shall be no more than 25%.
[0037] The gypsum board may further comprise a surface-protecting layer, which is attached to the board core and forms a laminated structure. Further, a priming coating layer may also be provided between the surface-protecting layer and the board core. The priming coating layer may be formed from a gypsum slurry without a foaming agent.
[0038] In another embodiment according to the present disclosure, provided is a process for preparing the gypsum slurry as described above, comprising the following steps:
[0039] Step 100, adding a solution of the foam stabilizer into a solution of the unstable foaming agent to give a foaming agent mixed solution.
[0040] Step 200, mixing the foaming agent mixed solution with water and injecting a gas for foaming, to give a second mixed solution. A specialized equipment is usually used for foaming, and the gas as usually used is air. Generally, sizes of bubbles in the soap solution can be controlled by adjusting air volume, foaming agent content, and foaming machine rotate speed.
[0041] Step 300, mixing the second mixed solution with a calcined gypsum, water, a starch, a reducing agent, a coagulant and a retarder with stirring for homogenization.
[0042] Provided is also a process for fabricating a gypsum board with the gypsum slurry as described above, comprising the following steps: Step 10, providing a first surface-protecting layer; Step 20, placing the gypsum slurry on the first surface-protecting layer to give a slurry layer, wherein the gypsum slurry is prepared by the process for preparing the gypsum slurry as describe above; Step 30, providing a second surface-protecting layer on the slurry layer to give a wet board body; Step 40, drying the wet board body. The process further comprises forming a priming coating layer on a side of the first surface-protecting layer and / or the second surfaceprotecting layer towards the slurry.
[0043] Specific Examples of various gypsum boards are provided as follows, wherein the gypsum slurries are prepared according to the following components:
[0044] Calcined gypsum 100 parts,
[0045] Starch 0.5 parts,
[0046] Foaming agent mixed solution 0.1 parts,
[0047] Water reducing agent 0.5 part,
[0048] Coagulant 0.3 parts,
[0049] Retarder 0.5 part,
[0050] Water 55 parts.
[0051] The foaming agent mixed solution is prepared according to Table 1.
[0052] Table 1
[0053]
[0054] As shown in Table 1, deviation values of the air hole diameters of the board core of the gypsum board are all less than 1.2, preferably less than 1.0.
[0055] Fig. 2 and Fig.3 correspond to images of the board core of the gypsum board of Example 10 and Example 6, respectively. It can be seen that as content of the foam stabilizer solution increases, the air hole diameters of the board core decrease. Moreover, as compared to prior foaming agent solution, the board core of the gypsum board obtained according to the present disclosure has more closed air holes, thereby reducing water absorption. In the above description, the details of the technical solutions of the present disclosure have been illustrated. However, those skilled in the art will appreciate that the present disclosure is not limited to the specific details listed in the above embodiments but can vary within the scope defined by the claims.
Claims
CLAIMS1. A foaming agent mixed solution, comprising an unstable foaming agent and a foam stabilizer, wherein the foam stabilizer is 3-50% of the total mass of the foaming agent mixed solution.
2. The foaming agent mixed solution according to claim 1, characterized in that, the foam stabilizer is a sodium alpha-olefin sulfonate solution.
3. A gypsum slurry, comprising the following components, on a mass basis,100 parts of a calcined gypsum;0.2-5 parts of a starch; and0.03-0.20 parts of the foaming agent mixed solution according to claim 1 or 2.
4. The gypsum slurry according to claim 3, characterized in that, the gypsum slurry further comprises,0.1-0.5 parts of a water reducing agent;0.1-1 parts of a coagulant;0.1-1 parts of a retarder; and50-70 parts of water.
5. A gypsum board, comprising a board core formed from the gypsum slurry according to claim 3 or 4 with air holes in the board core, characterized in that, the deviation value of diameters of the air holes is no more than 1.2.
6. The gypsum board according to claim 5, characterized in that, the deviation value of diameters of the air holes is no more than 1.0.
7. The gypsum board according to claim 5, characterized in that, the water absorption of the board core is no more than 25%.
8. A process for preparing the gypsum slurry according to claim 3 or 4, comprising the following steps:Step 100, adding a solution of a foam stabilizer into a solution of an unstable foaming agent to give a foaming agent mixed solution;Step 200, mixing the foaming agent mixed solution with water and injecting a gas for foaming, to give a second mixed solution;Step 300, mixing the second mixed solution with a calcined gypsum, water, a starch, a reducing agent, a coagulant and a retarder with stirring for homogenization.
9. A process for fabricating the gypsum board according to any one of claims 5-7 with the gypsum slurry prepared by the process according to claim 8, comprising the following steps:Step 10, providing a first surface-protecting layer;Step 20, placing the gypsum slurry on the first surface-protecting layer to give a slurry layer;Step 30, providing a second surface-protecting layer on the slurry layer to give a wet board body;Step 40, drying the wet board body.
10. The process according to claim 9, characterized in that, it further comprises forming a priming coating layer on a side of the first surface-protecting layer and / or the second surface-protecting layer towards the slurry.