Gypsum-based composition and gypsum board prepared using same

Abstract

The present invention provides a gypsum-based composition comprising gypsum, starch and fibers wherein the fibers are organic fibers, the weight fraction of the organic fibers being at least 0.5% of the weight of the gypsum, and the weight fraction of the starch being at least 0.5% of the weight of the gypsum. The invention also provides a gypsum board which comprises a core layer and at least one covering layer, the core layer and the covering layer form a laminated structure, and the core layer is formed by the gypsum-based composition. Organic fibers are used in the gypsum board, so that the use amount of the fibers can be reduced, and the strength of the gypsum board is improved.

Description

Technical Field

[0001] The present invention relates to gypsum building materials, in particular to a gypsum-based composition for making gypsum boards. Background Art

[0002] Gypsum board is a material made of building gypsum as the main raw material. It is a building material with light weight, high strength, thin thickness, easy processing, good sound insulation, heat insulation and fire resistance, and is one of the new lightweight boards currently being developed.

[0003] At present, the most common is the paper-faced gypsum board, which is a lightweight board made of gypsum slurry as the core and paper as the surface on both sides. The gypsum board is light in texture, high in strength, fireproof, mothproof and easy to process. Ordinary gypsum board is used for interior walls, partitions and ceilings. The water-resistant gypsum board with fireproof treatment can be used for the walls of rooms with high humidity, such as the lining of tiles, metal plates and plastic tiles in toilets, kitchens, bathrooms, etc. Summary of the invention

[0004] An object of the present invention is to provide a gypsum board product using organic fibers.

[0005] To this end, according to one aspect of the present invention, a gypsum-based composition comprises gypsum, starch and fiber, wherein the fiber is organic fiber, the weight fraction of the organic fiber is at least 0.5% of the weight of the gypsum, and the weight fraction of the starch is at least 0.5% of the weight of the gypsum.

[0006] Wherein, the organic fiber is polyethylene terephthalate fiber. Wherein, the weight fraction of the organic fiber is at least 1.5% of the weight of the gypsum.

[0007] Wherein, the weight fraction of the starch is at least 1%, or at least 2%, or at least 3% of the weight of the gypsum.

[0008] The gypsum-based composition further includes at least one of a dispersant, a foaming agent, a retarder, and an accelerator.

[0009] According to another aspect of the present invention, a gypsum board comprises a core layer and at least one covering layer, wherein the core layer and the covering layer form a laminated structure, wherein the core layer is formed of the above-mentioned gypsum-based composition.

[0010] The gypsum board further includes at least one primer layer disposed between the core layer and the cover layer, the primer layer being formed of the aforementioned gypsum-based composition.

[0011] The present invention uses organic fibers in the gypsum board, which can reduce the fiber dosage and improve the strength of the gypsum board. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 It is a schematic cross-sectional view of a gypsum board according to one embodiment of the present invention.

[0013] Figure 2 is a schematic diagram of the screw pull-out test on a gypsum board sample. DETAILED DESCRIPTION

[0014] Specific embodiments of the present invention are described below.

[0015] According to one embodiment of the present invention, a gypsum-based composition comprises gypsum, starch and fiber.

[0016] The fiber is an organic fiber, especially polyethylene terephthalate fiber (PET fiber), and its weight fraction is at least 0.5% or at least 1.5% of the weight of the gypsum. Usually, the fiber content does not exceed 3%. The fiber plays a role in enhancing strength, and short fibers are usually used, for example, the length is less than or equal to 6 mm.

[0017] The weight fraction of the starch is at least 0.5%, or at least 1%, or at least 2%, or at least 3% of the weight of the gypsum. Typically, the starch content does not exceed 10%.

[0018] The gypsum-based composition further includes at least one of a binder, a dispersant, a foaming agent, a retarder, and an accelerator.

[0019] The gypsum-based composition of the present invention may further include other optional additives according to actual needs, which may be one or more of a dispersant, a foaming agent, a retarder and an accelerator.

[0020] The dispersant may be an organic or inorganic dispersant, preferably a naphthalenesulfonate, such as sodium naphthalenesulfonate. The mass fraction of the dispersant is 0.01-1% of the mass of the gypsum.

[0021] The foaming agent may be a surfactant, such as any surfactant commonly used in the field of gypsum and available through commercial channels. The mass fraction of the foaming agent is 0.01-1% of the mass of the gypsum.

[0022] The retarder can be an organic or inorganic retarder, wherein the commonly used organic retarder is an organic acid or a polyamino acid, and the mass fraction thereof is 0.01-1% of the mass of the gypsum.

[0023] The coagulant is usually sulfate, and may also be other coagulants suitable for gypsum materials, and its mass fraction is 0.01-1% of the mass of the gypsum.

[0024] The above-mentioned raw materials can be obtained through commercial channels.

[0025] like Figure 1As shown, in another embodiment, the gypsum board 100 includes a core layer 120 formed of the above gypsum composition and cover layers 140 respectively attached to two opposite surfaces of the core layer 120. In this embodiment, the cover layer 140 is a face paper.

[0026] Optionally, the gypsum board has a primer layer 160, which is disposed between the core layer 120 and at least one face layer 140. The primer layer 160 is also formed based on the above-mentioned gypsum composition. The composition forming the primer layer 160 generally does not contain a foaming agent, so that the density of the primer layer 160 is greater than that of the core layer 120.

[0027] In other embodiments, the covering layer 140 may also be glass fiber felt, glass mesh cloth, non-woven fabric or polyvinyl alcohol layer.

[0028] The materials of the armor layer, other covering layers and reinforcement layers can all be obtained through commercial channels.

[0029] Several examples of gypsum boards are given below, and the screw pull-out strength of the samples is tested. In each example, the amount of each component is: 700 grams of gypsum, 40 grams of starch, 1.2 grams of dispersant, 0.35 grams of retarder, and 0.2 grams of accelerator. The amount of fiber is shown in each example in Table 1.

[0030] The gypsum board samples tested were made by the following process, including: 1. Mix the components in each example evenly; 2. Add 500 grams of water and stir evenly to form a slurry; 3. Set a face paper in the mold and pour the slurry into the mold; 4. Remove excess slurry and lay another face paper on the slurry; 5. After the slurry is initially set, dry it for 2 hours. The test sample size is 10 cm long, 10 cm wide and 1.2 cm thick.

[0031] The test method is as follows: First, fix a screw, such as a wood screw, at the center of the sample to be tested. Figure 2 Then, the screw is pulled out using the device and the required force is recorded in Newton. The test results are shown in Table 1.

[0032] Table 1

[0033] Fiber Type Fiber Addition (g) Pull-out strength (Newton) Comparison example Fiberglass 15 529 Example 1 PET fiber 15 620 Example 2 PET fiber 10.6 512 Example 3 PET fiber 8 548

[0034] It can be seen that in gypsum board, less PET fiber can be used to obtain higher screw pull-out strength, that is, the gypsum board has better nail holding force.

[0035] In the above description, the details of the technical solution of the present invention are explained. However, those skilled in the art can understand that the present invention is not limited to the specific details listed in the above embodiments, but can be changed within the scope defined by the claims.

Claims

1. A gypsum-based composition comprising gypsum, starch and fibers, wherein the fibers are organic fibers, the weight fraction of the organic fibers is at least 0.5% of the weight of the gypsum, and the weight fraction of the starch is at least 0.5% of the weight of the gypsum.

2. The gypsum-based composition according to claim 1, wherein The organic fiber is polyethylene terephthalate fiber.

3. The gypsum-based composition according to claim 1 or 2, wherein The weight fraction of the organic fiber is at least 1.5% of the weight of the gypsum.

4. The gypsum-based composition of claim 1, wherein The weight fraction of the starch is at least 1%, or at least 2%, or at least 3% of the weight of the gypsum.

5. The gypsum-based composition of claim 1, wherein Further comprising at least one of a dispersant, a foaming agent, a retarder and a coagulant.

6. A gypsum board comprising a core layer and at least one covering layer, wherein the core layer and the covering layer form a laminated structure, characterized in that: The core layer is formed from the gypsum-based composition according to any one of claims 1-5.

7. The gypsum board according to claim 6, characterized in that The method further comprises at least one primer layer disposed between the core layer and the cover layer, wherein the primer layer is formed based on the gypsum-based composition according to any one of claims 1 to 5.

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