A method for spraying gypsum paint that avoids dust and paint delamination

Abstract

This invention relates to the field of equipment for spraying mortar, insulating materials, or the like, and discloses a method for spraying gypsum paint that avoids dust and paint delamination. In this invention, the dry gypsum paint powder is placed in a water-soluble film inner packaging bag, and the entire bag is added to the spraying machine and covered during stirring, preventing dust generation during the stirring process. Simultaneously, the water used for mixing softens the water-soluble film into a gel-like substance and gradually dissolves it, without the bag interfering with the stirring. Furthermore, by first placing the water-soluble film inner packaging bag into a vacuum packaging bag and then filling it with the dry gypsum paint powder, the water-soluble film inner packaging bag is prevented from breaking during filling. Also, due to the presence of the water-soluble film inner packaging bag, the dry gypsum paint powder is not drawn into the vacuum packaging machine during vacuuming, ensuring a smooth vacuuming process. After vacuuming, the dry gypsum paint powder forms a hard block, thus preventing delamination during transportation.

Description

Technical Field

[0001] This invention relates to the field of equipment for spraying mortar, insulating materials or the like, and in particular to a method for spraying gypsum coatings that avoids dust and coating delamination. Background Technology

[0002] Gypsum paint is a very common type of paint used in building construction. It is generally used as a base coat to fill in the pits on the building surface and to facilitate the application of subsequent paints. Sometimes, gypsum paint is also used as a top coat for sound absorption purposes.

[0003] When used as a base coat, gypsum paint is typically applied using a spray gun. These spray guns have a built-in mixer; the dry gypsum paint powder is poured from the hopper into the mixer and mixed with water supplied from a pipe to form a slurry, which is then sprayed onto the wall. To prevent bags of gypsum paint from being poured into the hopper along with the dry powder, the hopper opening is usually fitted with wire mesh.

[0004] During the mixing process, the bag of gypsum paint powder is opened and placed on a wire mesh, allowing the powder to slowly leak out along the mesh and be mixed. This process generates a lot of dust, which is very detrimental to the health of construction workers.

[0005] In addition to the above, another problem with dry gypsum paint powder is the potential for stratification during transportation. The two main components of gypsum paint are calcined gypsum powder (specifically, hemihydrate calcined gypsum powder, also known as calcined gypsum powder) and filler powder. Calcined gypsum powder ensures bonding strength and imparts water resistance; filler powder makes the gypsum paint slurry easier to apply, increases smoothness, and reduces costs. A crucial requirement for filler powder is that it needs to be ground very finely to improve the smoothness of the gypsum paint surface. Therefore, the particle size of filler powder is much smaller than that of calcined gypsum powder. If the particle density of the filler powder (particle density is the density calculated after removing the gaps between particles, which is greater than the bulk density) differs significantly from that of the calcined gypsum powder, then the filler powder will stratify with the calcined gypsum powder during transportation.

[0006] The filler powders used in existing gypsum coatings mainly consist of talc powder (particle density approximately 2.7 g / cm³), light calcium carbonate powder (particle density approximately 2.4-2.6 g / cm³), or heavy calcium carbonate powder (particle density approximately 2.6-2.9 g / cm³). In contrast, the particle density of calcined gypsum powder in gypsum coatings is approximately 2.3 g / cm³, which is close to the particle density of various commonly used filler powders, thus making it less prone to stratification during transportation.

[0007] However, with the depletion of natural mineral resources, the natural mineral sources required for filler in existing gypsum coatings are becoming increasingly precious. Therefore, the industry is beginning to consider using renewable resources or solid waste to replace existing filler powders. Lithium slag powder is a feasible alternative because it is easily ground. However, lithium slag powder has a high particle density (due to its high alumina content), reaching 3.24 grams per cubic centimeter. When the inventors tried using lithium slag powder as a filler powder to formulate gypsum coatings, they found that it was more prone to separating from calcined gypsum powder during transportation.

[0008] A water-soluble film, as the name suggests, is an organic film that dissolves in water. It is commonly used in the textile industry and turns into a gel-like substance and dissolves when soaked in water. Due to its solubility, embroidery is sometimes done on a water-soluble film, such as in the production of lace, and then the film is removed by dissolving it in water.

[0009] The tensile strength of water-soluble film is highest when it is first produced, and its tensile strength is even no lower than that of polyethylene plastic film. However, its softness and tensile strength gradually decrease during storage. Summary of the Invention

[0010] This invention provides a gypsum paint spraying method that avoids dust and paint delamination.

[0011] The technical problem to be solved is that gypsum coatings are prone to generating a lot of dust during use, and if the gypsum coating uses components with a particle density that differs greatly from that of calcined gypsum powder, stratification is likely to occur during the transportation of the dry gypsum coating powder.

[0012] To solve the above-mentioned technical problems, the present invention adopts the following technical solution: a gypsum paint spraying method that can avoid dust and paint stratification, which is used to spray gypsum paint using a gypsum spraying machine with automatic water addition and stirring function, and avoids the stratification of gypsum paint dry powder before use;

[0013] The spraying method includes the following steps:

[0014] Step 1: Pack the mixed gypsum paint powder into a water-soluble film inner packaging bag, and then vacuum seal it with a vacuum packaging bag;

[0015] Step 2: Remove the wire mesh from the hopper opening of the plaster spraying machine and replace it with a movable cover plate to block dust.

[0016] Step 3: Transport the packaged gypsum paint powder to the construction site, turn on the gypsum spraying machine, open the vacuum packaging bag and take out the gypsum paint powder wrapped in the water-soluble film inner packaging bag. Put the gypsum paint powder and the water-soluble film inner packaging bag into the hopper together and cover the hopper opening with the movable cover plate.

[0017] Step 4: Stir and spray the plaster coating.

[0018] Furthermore, the vacuum packaging bag is a packaging bag with a heat-sealed opening. A sealing bar is also provided between the heat-sealed opening and the water-soluble film inner packaging bag to prevent the water-soluble film inner packaging bag from being pulled out during vacuuming and to prevent the water-soluble film inner packaging bag from being torn when the vacuum packaging bag is cut open. The sealing bar is set parallel to the length direction of the heat-sealed opening, and its two ends are flush with the two ends of the heat-sealed opening.

[0019] Furthermore, the sealing bar is a cardboard tube.

[0020] Furthermore, the shaft of the mixing paddle in the plaster spraying machine is set horizontally.

[0021] Furthermore, in step one, the inner packaging bag of the water-soluble film is first placed into the vacuum packaging bag, and then the dry powder of gypsum paint is filled in. During filling, the inner packaging bag of the water-soluble film is not completely filled. After filling, the opening of the inner packaging bag of the water-soluble film is bent towards the bottom of the bag along the gap between the vacuum packaging bag and the inner packaging bag of the water-soluble film.

[0022] Furthermore, one edge of the movable cover plate is hinged to one edge of the hopper of the plaster spraying machine.

[0023] Furthermore, the gypsum coating powder contains at least one component whose particle density differs from that of calcined gypsum powder by more than 0.8 grams per cubic centimeter, and includes a segregating component whose particles are in a shape other than fibrous.

[0024] Furthermore, the gypsum coating powder contains calcined gypsum powder and lithium slag powder as a filler.

[0025] Furthermore, the gypsum coating powder also contains titanium dioxide for adjusting whiteness.

[0026] Furthermore, the vacuum packaging bag is a polyvinyl chloride plastic bag, and the inner packaging bag of the water-soluble film is made of cold water-soluble film.

[0027] The gypsum paint spraying method of the present invention, which avoids dust and paint delamination, has the following advantages compared with the prior art:

[0028] In this invention, by packaging the dry gypsum paint powder into a water-soluble film inner packaging bag, and then placing the entire bag into the spraying machine and covering it during stirring without opening the bag, there will be no dust during the stirring process. At the same time, the mixing water will soften the water-soluble film into a gel-like substance during stirring (incomplete dissolution is not a problem, because the sprayed gypsum paint layer is several centimeters thick, and adding some gel-like substance will actually increase the strength) and gradually dissolve it. The bag of water-soluble film will not affect the stirring.

[0029] In this invention, by first placing the water-soluble film inner packaging bag into a vacuum packaging bag and then filling it with gypsum paint powder, the water-soluble film inner packaging bag is prevented from being torn during the filling process (the water-soluble film becomes less flexible and less tensile after long-term storage). Simultaneously, the presence of the water-soluble film inner packaging bag prevents the gypsum paint powder from being drawn into the vacuum packaging machine during vacuuming, ensuring a smooth vacuuming process. After vacuuming, the gypsum paint powder and the water-soluble film inner packaging bag together form a solid block, preventing the gypsum paint powder from separating during transportation and preventing the water-soluble film inner packaging bag from breaking due to repeated bending. Attached Figure Description

[0030] Figure 1 A schematic diagram of packaged gypsum paint powder;

[0031] Figure 2 A schematic diagram of a plaster spraying machine with a movable cover plate;

[0032] In the diagram, 1-vacuum packaging bag, 11-heat melt seal, 12-sealing bar, 2-water-soluble film inner packaging bag, 3-plaster spraying machine, 31-movable cover plate. Detailed Implementation

[0033] A method for spraying gypsum paint that avoids dust and paint separation is used to spray gypsum paint using a gypsum spraying machine 3 with automatic water addition and stirring function, and to prevent the dry powder of gypsum paint from separating before use.

[0034] Existing gypsum spraying systems generally come with an automatic water-adding and mixing function, which includes a water supply pipe that can be connected to a faucet to automatically add water.

[0035] The spraying method includes the following steps:

[0036] Step 1: As Figure 1 As shown, the mixed gypsum paint powder is packed into a water-soluble film inner packaging bag 2, and then vacuum sealed with a vacuum packaging bag 1.

[0037] The water-soluble film inner packaging bag 2 and the vacuum packaging bag 1 work together. If the gypsum paint powder is directly filled into the vacuum packaging bag 1, a large amount of gypsum paint powder will be sucked in during vacuuming, damaging the vacuum packaging machine. At the same time, the vacuum packaging bag 1 protects the water-soluble film inner packaging bag 2, ensuring that it will not be scratched during transportation or broken due to repeated bending (because the water-soluble film inner packaging bag 2 becomes brittle after long-term storage and will break after repeated bending; here, after vacuuming, it forms a hard block with the gypsum paint powder and cannot be bent). This ensures that the water-soluble film inner packaging bag 2 is intact before use and can be completely inserted into the gypsum spraying machine 3 without generating dust.

[0038] Step Two: As Figure 2 As shown, remove the wire mesh at the hopper opening of the plaster spraying machine 3 and replace it with a movable cover plate 31 for blocking dust.

[0039] The existing gypsum spraying machine 3 has a wire mesh at the hopper opening to hold the dry gypsum paint powder. After the dry gypsum paint powder is unpacked, the opening is closed onto the wire mesh, allowing the powder to fall through the mesh without the bag entering. Here, because the dry gypsum paint powder needs to be fed into the hopper along with the water-soluble inner packaging bag 2, this wire mesh needs to be removed.

[0040] The movable cover 31 here not only blocks dust but also serves a protective function. After the construction workers throw the dry gypsum paint powder into the hopper, the mixing paddle is isolated from the outside by the movable cover 31. Note that in order for the movable cover 31 to close smoothly, the inner packaging bag 2 of the water-soluble film must be smaller than the hopper.

[0041] Step 3: Transport the packaged gypsum paint powder to the construction site, turn on the gypsum spraying machine 3, open the vacuum packaging bag 1 and take out the gypsum paint powder wrapped in the water-soluble film inner packaging bag 2. Put the gypsum paint powder and the water-soluble film inner packaging bag 2 into the hopper, and cover the hopper opening with the movable cover plate 31. After the gypsum paint powder is put into the hopper, cover the movable cover plate 31 and stir it to prevent dust.

[0042] Step 4: Stir and spray the plaster coating.

[0043] The vacuum packaging bag 1 is a packaging bag with a heat-sealed opening 11. A sealing bar 12 is also provided between the heat-sealed opening 11 and the water-soluble film inner packaging bag 2 to prevent the water-soluble film inner packaging bag 2 from being pulled out during vacuuming and to prevent the water-soluble film inner packaging bag 2 from being torn when the vacuum packaging bag 1 is cut. The sealing bar 12 is set parallel to the length direction of the heat-sealed opening 11, and its two ends are flush with the two ends of the heat-sealed opening 11.

[0044] During vacuum packaging, the water-soluble film inner packaging bag 2 may be drawn out of the vacuum packaging bag 1 due to the suction. Therefore, a sealing bar 12 is used to prevent this. At the same time, when the vacuum packaging bag 1 is opened, it may be cut along with the inner water-soluble film packaging bag 2. Therefore, the sealing bar 12 is set to stop the blade. When opening the bag, the blade is used to cut the part of the vacuum packaging bag 1 between the sealing bar and the heat-sealed 11, with the sealing bar 12 separating the blade from the inner water-soluble film packaging bag 2, so the blade will not cut the inner water-soluble film packaging bag 2.

[0045] In this embodiment, the sealing bar 12 is a cardboard tube, which is low in cost and lightweight.

[0046] In the plaster spraying machine 3, the agitator shaft is horizontally positioned so that it quickly tears the water-soluble film inner packaging bag 2 after it is fed into the hopper. Ideally, the agitator blades should have sharp points at the end to quickly cut open the water-soluble film inner packaging bag 2. Of course, without these features, the water-soluble film inner packaging bag 2 will also be quickly torn by the agitator upon contact with the mixing water, but this process will create significant resistance to the agitator and may damage the motor.

[0047] In step one, first put the water-soluble film inner packaging bag 2 into the vacuum packaging bag 1, and then fill it with gypsum paint dry powder. When filling, do not completely fill the water-soluble film inner packaging bag 2. After filling, bend the bag opening of the water-soluble film inner packaging bag 2 towards the bottom of the bag along the gap between the vacuum packaging bag 1 and the water-soluble film inner packaging bag 2.

[0048] The purpose of this procedure is to allow the use of the water-soluble film inner packaging bag 2, which has become less flexible after prolonged storage. When filling the dry gypsum paint powder, placing the water-soluble film inner packaging bag 2 inside the vacuum packaging bag 1 provides protection and prevents it from bursting. After filling, instead of tying the opening, the bag is folded and tucked between the two bags. During vacuuming, the gas inside the water-soluble film inner packaging bag 2 can be extracted without bursting.

[0049] One edge of the movable cover plate 31 is hinged to one edge of the hopper of the plaster spraying machine 3. This is a common practice, that is, the two edges are hinged together by a pin parallel to them, so that the movable cover plate 31 can be lifted up and down, and can smoothly seal the entire hopper opening when closed. Of course, a steel plate not connected to the hopper can also be used as the movable cover plate 31, but in this case, the steel plate is easy to fall off after being closed, and the steel plate needs to be larger.

[0050] The dry powder of gypsum coating contains at least one component whose particle density differs from that of calcined gypsum powder by more than 0.8 grams per cubic centimeter. Remember the component that is prone to stratification. The density of calcined gypsum powder is about 2.3 grams per cubic centimeter. 0.8 grams per cubic centimeter is more than one-third of the particle density of calcined gypsum powder. According to experience in ore particle flotation, a particle density difference of more than 1 / 3 will easily cause stratification.

[0051] In addition, stratification is more likely to occur if the particles of the easily stratified component are not fibrous. If the particles of the easily stratified component are fibrous, such as the wood fiber powder often mixed in gypsum coatings, stratification will not occur even if the particle density differs greatly from that of calcined gypsum powder.

[0052] In this embodiment, the gypsum coating powder contains calcined gypsum powder and lithium slag powder as a filler. The lithium slag powder has a particle density of approximately 3.24 g / cm³, making it easy to settle below the calcined gypsum powder during transportation. The gypsum coating powder also contains an optional component: titanium dioxide, used to adjust whiteness, with a particle density of approximately 3.9 g / cm³, which also tends to settle below the calcined gypsum powder.

[0053] This gypsum coating is a novel coating developed by the inventor. It utilizes lithium slag powder, a solid waste, to replace mineral raw materials such as talc. The lithium slag powder contains glass microspheres and has a wide particle size distribution, thus improving the coating's filling properties, enhancing adhesion, and reducing the likelihood of peeling. However, during use, the inventor discovered a problem with its tendency to delaminate during transportation. Therefore, the inventor developed the aforementioned packaging and usage method as a complementary solution. This packaging and usage method also has the added benefit of preventing dust generation.

[0054] Specifically, this gypsum coating contains the following components:

[0055] 30-70 parts of calcined gypsum powder;

[0056] 30-70 parts of filler powder; the filler powder is lithium slag powder whose whiteness is improved by adding titanium dioxide or lithium slag powder with higher whiteness, and the whiteness of the filler powder is not less than 55%; and the mesh size of the lithium slag powder is not less than 800 mesh.

[0057] If used as a base coat, pure lithium slag powder can be used as the filler powder. If used as a top coat, the whiteness of the lithium slag powder may not meet the requirements (the whiteness of lithium slag powder fluctuates greatly). Therefore, whiter lithium slag powder can be added to adjust its whiteness to the required level (high-whiteness lithium slag powder is scarce and needs to be used sparingly). If the whiteness of the available lithium slag powder is not satisfactory, titanium dioxide needs to be used to adjust the whiteness. Titanium dioxide has high whiteness and good hiding power, thus effectively improving whiteness.

[0058] 0.4-1 part of hydrophilic fiber powder. The hydrophilic fiber powder is wood fiber powder or waste paper fiber powder. The hydrophilic fiber powder is also mixed with sodium carboxymethyl cellulose to further improve the bonding strength between the hydrophilic fiber powder and the rest of the gypsum coating. The content of sodium carboxymethyl cellulose in the hydrophilic fiber powder is 6%-10%wt.

[0059] In this embodiment, the vacuum packaging bag 1 is a polyvinyl chloride (PVC) plastic bag. Since the vacuum packaging bag 1 is not for packaging food, it is not necessary to use expensive food-grade packaging bags; inexpensive PVC can be used. Furthermore, PVC has good low-temperature flexibility and will not become brittle in cold weather, thus protecting the contents. Also, there are many PVC components on construction sites, making PVC convenient for subsequent recycling.

[0060] In this embodiment, the inner packaging bag 2 of the water-soluble film is made of cold water-soluble film, thus eliminating the need for heating. Cold water-soluble film is a type of water-soluble film available on the market and commonly sold by various vendors.

[0061] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Various modifications and improvements made by those skilled in the art to the technical solutions of the present invention without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.

Claims

1. A method for spraying gypsum paint that avoids dust and paint delamination, characterized in that: Used for spraying gypsum coatings with a gypsum spraying machine (3) with automatic water mixing function, and to prevent the gypsum coating dry powder from separating before use; The spraying method includes the following steps: Step 1: Pack the mixed gypsum paint powder into a water-soluble film inner packaging bag (2), and then vacuum seal it with a vacuum packaging bag (1); Step 2: Remove the wire mesh from the hopper opening of the plaster spraying machine (3) and replace it with a movable cover plate (31) to block dust. Step 3: Transport the packaged gypsum paint powder to the construction site, turn on the gypsum spraying machine (3), open the vacuum packaging bag (1) and take out the gypsum paint powder wrapped in the water-soluble film inner packaging bag (2), put the gypsum paint powder together with the water-soluble film inner packaging bag (2) into the hopper, and cover the hopper opening with the movable cover plate (31); Step 4: Stir and spray the plaster coating; In step one, first put the water-soluble film inner packaging bag (2) into the vacuum packaging bag (1), and then fill it with gypsum paint dry powder. When filling, do not completely fill the water-soluble film inner packaging bag (2). After filling, bend the bag opening of the water-soluble film inner packaging bag (2) towards the bottom of the bag along the gap between the vacuum packaging bag (1) and the water-soluble film inner packaging bag (2).

2. The gypsum paint spraying method according to claim 1, which avoids dust and paint delamination, is characterized in that: The vacuum packaging bag (1) is a packaging bag with a heat-sealed opening (11). A sealing bar (12) is provided between the heat-sealed opening (11) and the water-soluble film inner packaging bag (2) to prevent the water-soluble film inner packaging bag (2) from being pulled out when vacuuming and to prevent the water-soluble film inner packaging bag (2) from being torn when the vacuum packaging bag (1) is cut. The sealing bar (12) is set parallel to the length direction of the heat-sealed opening (11) and its two ends are flush with the two ends of the heat-sealed opening (11).

3. The gypsum paint spraying method according to claim 2, which avoids dust and paint delamination, is characterized in that: The sealing bar (12) is a cardboard tube.

4. The gypsum paint spraying method according to claim 1, which avoids dust and paint delamination, is characterized in that: The agitator shaft of the agitator in the gypsum spraying machine (3) is set horizontally.

5. A gypsum paint spraying method according to claim 1 that avoids dust and paint delamination, characterized in that: One edge of the movable cover plate (31) is hinged to one edge of the hopper of the gypsum spraying machine (3).

6. The gypsum paint spraying method according to claim 1, which avoids dust and paint delamination, is characterized in that: The gypsum coating powder contains at least one component whose particle density differs from that of calcined gypsum powder by more than 0.8 grams per cubic centimeter, and is designated as an easily segregated component. The particles of the easily segregated component are in a shape other than fibrous.

7. A gypsum paint spraying method according to claim 6 that avoids dust and paint delamination, characterized in that: The gypsum coating powder contains calcined gypsum powder and lithium slag powder as a filler.

8. A gypsum paint spraying method according to claim 7 that avoids dust and paint delamination, characterized in that: The gypsum coating powder also contains titanium dioxide to adjust whiteness.

9. A method for spraying gypsum paint according to claim 1, which avoids dust and paint delamination, characterized in that: The vacuum packaging bag (1) is a polyvinyl chloride plastic bag, and the water-soluble inner packaging bag (2) is made of cold water-soluble film.

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