A water-based edge-sealing coating for flooring, preparation method thereof, and spraying equipment

Abstract

The present invention relates to the technical field of floor coatings, and discloses a water-based edge-sealing coating for flooring, a preparation method thereof, and spraying equipment. The water-based edge-sealing coating for flooring comprises a main agent, a film-forming aid, a water-based additive, and a thickener. The main agent is a silane-modified waterborne polyurethane-modified acrylic emulsion, and the water contact angle of the water-based edge-sealing coating for flooring is ≥100°. The water-based coating, which uses the waterborne polyurethane-modified acrylic emulsion as a main ingredient, is virtually unaffected by changes in ambient humidity and can effectively and long-term protect the tongue-and-groove or lock-and-lock areas of wooden floors. Furthermore, as a water-based system coating, it is a more environmentally friendly edge-sealing coating.

Description

Technical Field

[0001] The present invention relates to the technical field of floor coatings, and in particular to a water-based edge-sealing coating for floors. The present invention also relates to a preparation method for the water-based edge-sealing coating, and spraying equipment for the water-based edge-sealing coating. Background Art

[0002] Wood flooring is made from processed wood materials and includes solid wood flooring made from solid wood boards, composite flooring made from multi-layer composite boards, and laminate flooring made from high-density fiberboard. Wood expands and contracts when wet, so wood flooring often changes in size and shape due to changes in ambient temperature and humidity.

[0003] In order to prevent wooden floors from being affected by ambient temperature and humidity, paint with a certain waterproof effect is often roller-coated or curtain-coated on the surface and back of the floor, and edge sealing agents with a certain waterproof effect are sprayed on the four sides of the floor (which are also the tongue and groove surfaces). Common edge sealing agents include water-based paint, molten paraffin, etc., and molten paraffin has the widest range of applications, and can be used for tongue and groove waterproof edge sealing treatment of solid wood flooring, composite flooring, laminate flooring and other products.

[0004] For example, in the Chinese Patent Database, the invention patent application with publication number CN103509490A, titled "A Hot Melt Adhesive for Furniture Edge Sealing," describes a hot melt adhesive composed of the following raw materials in parts by weight: 70-80 parts ethylene-vinyl acetate copolymer, 10-15 parts liquid paraffin, 2-3 parts glycerol triglyceride, 1-2 parts hexamethylphosphoric triamide, 6-10 parts nano-bauxite, 8-10 parts talc, 0.1-0.2 parts tin isooctyl dimethyldimercaptoacetate, and 10-15 parts tackifier. This hot melt adhesive has strong adhesion and is suitable for edge sealing of wood furniture and flooring. The coating is stable and highly weather-resistant. Another example is the technical solution described in the invention patent application with publication number CN102086347A, titled "Laminate Flooring Edge Sealing Agent, Preparation Method, and Application thereof." Specifically, this laminate flooring edge sealing agent includes 2-6 parts wax, 20-40 parts resin, 20-40 parts ester solvent, and 2-50 parts alkane solvent. It has the advantages of high adhesion, high permeability, fast drying, no coating after drying, matte finish, low odor and environmental protection.

[0005] However, paraffin or other wax-containing coatings will gradually evaporate and lose with changes in ambient temperature and humidity during long-term use, reducing the waterproof or protective effect or even making it ineffective, shortening the shelf life of the product and posing certain quality risks. Summary of the Invention

[0006] The technical purpose of this case is to overcome at least one of the above-mentioned technical problems and provide a water-based edge-sealing coating for floors, which is a water-based coating with water-based polyurethane-modified acrylic emulsion as the main ingredient. Therefore, it is almost unaffected by changes in environmental humidity and can effectively protect the tongue and groove or lock of wooden floors for a long time. At the same time, as a water-based system coating, it is a more environmentally friendly edge-sealing coating.

[0007] To achieve the above-mentioned technical objectives, one aspect of this case provides a water-based edge-sealing paint for floors, which includes a main agent, a film-forming aid, a water-based aid and a thickener. The main agent is a water-based polyurethane-modified acrylic emulsion modified with silane, and the water contact angle of the water-based edge-sealing paint for floors is ≥100°.

[0008] Preferably, the weight proportions of the components in the water-based edge-sealing paint for flooring are: main agent 80%, film-forming agent 6-10%, water-based additive 0.2%, thickener 0.2%, and water 8-10%.

[0009] This case also provides a preparation method suitable for this type of edge-sealing water-based coating, including the preparation of a main agent, which includes a preparation step of water-based polyurethane, and a preparation step of adding an acrylic monomer to the water-based polyurethane to prepare a water-based polyurethane-modified acrylic emulsion; a silane coupling agent monomer is added simultaneously with the acrylic monomer.

[0010] Preferably, the preparation of the main agent includes the following steps:

[0011] Step 1: using isophorone diisocyanate as a hard segment, adding a hydrophilic monomer and a catalyst and heating to 90° C. to obtain a first prepolymer;

[0012] Step 2, continuing the above step 1 until the -NCO reaches a first set value, adding a chain extender to obtain a second prepolymer, adding a capping agent to obtain a double-bond terminated prepolymer when the -NCO reaches a second set value, adding a neutralizing agent to obtain a third prepolymer when the -NCO reaches a third set value, and after 45-55 minutes, adding deionized water to emulsify the third prepolymer for 1-1.5 hours to obtain a waterborne polyurethane;

[0013] Step 3: adding acrylic acid monomer, crosslinking agent, deionized water, silane coupling agent monomer, and initiator to the waterborne polyurethane to obtain a pre-emulsion;

[0014] Step 4, weighing deionized water in a container and heating it to 80° C., dripping the pre-emulsion into the container, heating it to 85° C. and keeping it warm to obtain a fourth prepolymer;

[0015] Step 5: adding a post-initiator to the fourth prepolymer to obtain a fifth prepolymer, and obtaining a silane-modified waterborne polyurethane-modified acrylic emulsion by heat preservation, filtration, and discharging.

[0016] Preferably, the silane coupling agent monomer used includes γ-methacryloxypropyltrimethoxysilane and / or vinyltri(β-methoxyethoxy)silane.

[0017] Preferably, the acrylic monomer includes a mixture of one or more of methyl methacrylate, butyl acrylate, and hydroxyethyl acrylate, and the chain extender is 2,2-dihydroxymethylpropionic acid and / or 1,4-butanediol.

[0018] The present case also provides a spraying device suitable for this type of edge-sealing water-based paint, including a vacuum spraying mechanism arranged at an angle, the vacuum spraying mechanism including a limit assembly, a vacuum nozzle assembly, a paint source connected to the vacuum nozzle assembly pipeline, and a mounting shaft; the mounting shaft is fixedly mounted on the frame, and the limit assembly can rotate relative to the mounting shaft; the limit assembly includes an upper limit ring and a lower limit ring mounted on the mounting shaft, the upper limit ring can suck from its limit working surface on the inner side of the ring, and the lower limit ring can suck from its limit working surface on the inner side of the ring; the vacuum nozzle assembly is fixedly mounted on the mounted shaft, the vacuum nozzle assembly is located between the upper limit ring and the lower limit ring, and abuts against the upper limit ring and the lower limit ring; the limit assembly and the vacuum nozzle assembly can cooperate with the female tenon of the floor block to form a spraying operation chamber.

[0019] Preferably, the upper limit ring includes an upper limit cavity with a trumpet opening, an upper suction channel provided on the cavity wall of the upper limit cavity, and an upper suction component sealedly inserted in the upper suction channel, the outer wall of the upper limit cavity abuts and fits with the surface of the floor block, and the upper suction component is connected to the vacuum air source pipeline; the lower limit ring includes a lower limit cavity with a trumpet opening, a lower suction channel provided on the cavity wall of the lower limit cavity, and a lower suction component sealedly inserted in the lower suction channel, the outer wall of the lower limit cavity abuts and fits with the side of the floor block, and the lower suction component is connected to the vacuum air source pipeline.

[0020] Preferably, the upper limit cavity is divided into a first part of the upper limit cavity and a second part of the upper limit cavity which are coaxial and set with a gap, the gap being the upper suction channel, and the upper suction component including an upper fixing ring which is sealingly connected to the first part of the upper limit cavity and the second part of the upper limit cavity, an upper through hole provided on the upper fixing ring, and an upper suction tube which is sealingly inserted into the upper through hole; the lower limit cavity is divided into a first part of the lower limit cavity and a second part of the lower limit cavity which are coaxial and set with a gap, the gap being the lower suction channel, and the lower suction component including a lower fixing ring which is sealingly connected to the first part of the lower limit cavity and the second part of the lower limit cavity, a lower through hole provided on the lower fixing ring, and a lower suction tube which is sealingly inserted into the lower through hole.

[0021] Preferably, the extension line of the axis of the vacuum nozzle of the vacuum nozzle assembly passes through the connection between the inner side surface of the groove of the female tenon and the bottom surface of the groove.

[0022] In summary, the water-based edge-sealing coating for flooring disclosed in the present application and the spraying method and equipment thereof have at least the following advantages:

[0023] 1. In this case, by modifying water-based polyurethane-modified acrylic emulsion with silicone, a water-based coating with hydrophobicity, high and low temperature resistance, anti-fouling properties, long protective period and almost unaffected by ambient temperature and humidity is obtained.

[0024] 2. In this case, by first synthesizing a vinyl-terminated polyurethane emulsion to adjust the chain structure of the water-based polyurethane, it is made self-emulsifying and no longer requires the use of an emulsifier, thereby improving the overall performance of the water-based polyurethane-modified acrylic emulsion; further, by introducing a silane coupling agent as a functional monomer into the polyurethane acrylic resin, the hydrophobicity and thermal stability of the resin are improved.

[0025] 3. In this case, by means of the coordination between the limiting components and the surface and side (lower side) of the floor blocks, and the extension position of the vacuum spraying components, the atomized paint can be sprayed onto the surface and side of the floor blocks, and the water-based paint can be evenly sprayed on the surface of the female tenon. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present application. For those skilled in the art, other drawings can be obtained based on these drawings without paying any creative labor.

[0027] Figure 1 This is a schematic structural diagram of the vacuum spraying mechanism of an embodiment of the present application.

[0028] Figure 2 This is a schematic diagram of the vacuum spraying mechanism in use according to an embodiment of the present application.

[0029] Figure 3 This is a schematic cross-sectional structural diagram of the vacuum spraying mechanism of an embodiment of the present application.

[0030] Figure 4 This is another cross-sectional structural schematic diagram of the vacuum spraying mechanism of an embodiment of the present application.

[0031] In the figure: 100, floor block, 101, retreat surface, 102, groove top surface, 103, groove inner side surface, 104, groove bottom surface, 105, groove outer side surface, 106, support surface, 107, lower side surface, 200, vacuum spraying mechanism, 210, vacuum nozzle assembly, 211, annular sleeve, 212, vacuum spraying component, 220, limit assembly, 221, upper limit cavity, 2211, first part upper limit cavity, 2212, second part upper limit cavity, 222, upper suction component, 2221, upper fixing ring, 2222, upper suction pipe, 223, lower limit cavity, 2231, first part lower limit cavity, 2232, second part lower limit cavity, 224, lower suction component, 2241, lower fixing ring, 2242, lower suction pipe, 230, mounting shaft. DETAILED DESCRIPTION

[0032] In order to enable those skilled in the art to better understand the technical solutions in this application, the technical solutions in the embodiments of this application will be clearly and completely described below in conjunction with the drawings in the embodiments of this application. Obviously, the described embodiments are only part of the embodiments of this application, not all of the embodiments. Based on the embodiments of this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts should fall within the scope of protection of this application.

[0033] A method for preparing a water-based edge-sealing coating for flooring includes the preparation of a main agent, which comprises the following steps:

[0034] Step 1: Using isophorone diisocyanate (IPDI) as the hard segment, adding a hydrophilic monomer and a catalyst, heating to 90° C. to obtain a first prepolymer, and measuring the -NCO (isocyanate group) concentration in the system every 0.5 h;

[0035] Step 2: Continue the above step 1 until the -NCO reaches the theoretical value, then add a chain extender to obtain a second prepolymer. Similarly, when the -NCO reaches the theoretical value, add a capping agent to obtain a double-bond terminated prepolymer. When the -NCO reaches the theoretical value, cool and add a neutralizing agent to obtain a third prepolymer. After 45-55 minutes, add deionized water to emulsify the third prepolymer for 1-1.5 hours to obtain a waterborne polyurethane. The -NCO concentration at each stage is calculated according to the di-n-butylamine method.

[0036] Step 3: Adding acrylic acid monomer, crosslinking agent, deionized water, silane coupling agent monomer, and initiator to waterborne polyurethane to obtain a pre-emulsion;

[0037] Step 4, weighing deionized water in a container and heating it to 80° C., dripping the pre-emulsion into the container, heating it to 85° C. and keeping it warm to obtain a fourth prepolymer;

[0038] Step 5: adding a post-initiator dropwise to the fourth prepolymer to obtain a fifth prepolymer, and obtaining a silane-modified waterborne polyurethane-modified acrylic emulsion by heat preservation, filtration, and discharging.

[0039] The preparation method of this embodiment is described below in detail by taking the preparation of 100 g of the main agent as an example.

[0040] In step 1, the amount of isophorone diisocyanate (IPDI) added is 18 g; the water-based monomer is polyether diol (DL2000), the amount of which is 68 g; and the catalyst is dibutyltin dilaurate (T12), the amount of which is 0.02 g.

[0041] In step 2, the chain extender includes 2,2-dihydroxymethylpropionic acid (DMPA) and 1,4-butanediol (BDO), with the addition amounts being 2 g and 3 g, respectively; the end capping agent is hydroxyethyl acrylate (HEA), with the addition amount being 4 g; the neutralizing agent is triethanolamine (TEA), with the addition amount being 5 g; and the addition amount of deionized water is 150 g.

[0042] In step 3, the acrylic monomers include methyl methacrylate (MMA), butyl acrylate (BA) and hydroxyethyl acrylate (HEA), with the addition amounts of 10 g, 3.5 g and 7.5 g, respectively; the crosslinking agent is trimethylolpropane triacrylate (TMPTA) or N,N-methylenebisacrylamide (MBA), with the addition amount of 0.2 g or 0.18 g; the addition amount of deionized water is 50 g; the silane coupling agent monomer is γ-methacryloyloxypropyltrimethoxysilane (KH-570) and / or vinyl tris(β-methoxyethoxy)silane (A-172); the initiator is potassium persulfate (KPS) dissolved in deionized water, with the addition amount of 0.15 g.

[0043] In step 4, weigh 50 g of deionized water and add it to a four-necked flask. Heat the mixture to 80°C. Simultaneously, transfer the pre-emulsion obtained in step 3 to a constant-pressure separatory funnel and add the pre-emulsion dropwise to the flask. Control the flow rate to complete the addition over 3 hours. Then, heat the mixture to 85°C and maintain for 1 hour.

[0044] In step 5, the post-initiator is potassium persulfate (KPS), and the added amount is 0.15 g.

[0045] Table 1 shows the silane coupling agent monomers and the amounts added in the preparation methods of Examples 1 to 3.

[0046] Table 1. Silane coupling agent monomers and addition amounts in the preparation methods of Examples 1 to 3

[0047]

[0048] Control Example 1: The difference between Control Example 1 and Example 1 is that no silane coupling agent monomer is added in step 3.

[0049] Control Example 2: The difference between Control Example 2 and Example 1 is that in step 2, no emulsifier is added instead of the capping agent.

[0050] Control Example 3: The difference between Control Example 3 and Example 1 is that no emulsifier is added in place of the end-capping agent in step 2, and no silane coupling agent monomer is added in step 3.

[0051] Table 2 shows the performance parameters of the main agent (modified waterborne polyurethane acrylate) of Examples 1-3 and the main agent (waterborne polyurethane acrylate) of Comparative Examples 1-3.

[0052] Table 2. Performance parameters of the main agent of Examples 1-3 and Comparative Examples 1-3

[0053] Example Water contact angle / ° Gel rate / % Example 1 87 2.2 Example 2 100 4.0 Example 3 98 3.4 Comparative Example 1 72 0.5 Comparative Example 2 80 1.5 Comparative Example 3 70 1.4

[0054] Traditional acrylic resin emulsion polymerization for wood requires the addition of an emulsifier, but the addition of an emulsifier not only reduces the water resistance of the coating but also affects its mechanical properties. In this embodiment, by first synthesizing a vinyl-terminated polyurethane emulsion to adjust the segment structure of the waterborne polyurethane, it can form a relatively stable dispersion in a water-based system. Its self-emulsification property eliminates the need for an emulsifier, thereby improving the overall performance of the waterborne polyurethane-modified acrylic emulsion.

[0055] Furthermore, the water resistance of water-based wood coatings is relatively poor. In this embodiment, a silane coupling agent is introduced into the polyurethane acrylic resin as a functional monomer, and the -Si-O- and -Si-C- functional groups in the silane coupling agent are grafted into the resin chain segments to improve the hydrophobicity of the resin. At the same time, the double bond structure contained in the silane coupling agent molecule can increase the cross-linking degree of the resin and improve the thermal stability of the resin.

[0056] In this preparation method, the synthesis route of γ-methacryloxypropyltrimethoxysilane (KH-570) modified waterborne polyurethane acrylate is:

[0057]

[0058]

[0059] The synthetic route of vinyl tris(β-methoxyethoxy)silane (A-172) modified waterborne polyurethane acrylate is:

[0060]

[0061] The main agent prepared by the method of the above-mentioned Examples 1-3 is used to prepare the edge sealing water-based floor coating of Examples 1-3 through the following steps:

[0062] Step 1: Place 100g of the main agent (modified waterborne polyurethane acrylate) obtained above in a polytetrafluoroethylene beaker, add 10g of film-forming aid, and stir at a speed of 500r / min for 25min;

[0063] Step 2: Add water-based additives, including water-based leveling agent and water-based defoamer, in amounts of 0.1 g and 0.15 g, respectively, and stir at 400 r / min for 20 min;

[0064] Step 3, adding a thickener, the thickener is a polyurethane thickener, the addition amount is 0.25g, and stirring at 150r / min for 15min;

[0065] Step 4: Use a 100-mesh filter cloth to filter and obtain the water-based edge sealing paint for the floor.

[0066] The main agent prepared by the method of reference examples 1-3 was used in the same manner as above to prepare the edge-sealing water-based coatings for floors of reference examples 1-3.

[0067] Comparative Example 4: Heat and melt the paraffin wax, and use a vacuum edge sealing sprayer to evenly apply the molten paraffin wax on the flat wood surface, let it stand and solidify, and the coating thickness is 0.05 mm.

[0068] The floor edge-sealing water-based coatings obtained in Examples 1-3 and Reference Examples 1-3 were applied to a flat timber surface using the vacuum spraying method of the prior art. The coating thickness was 0.03 mm to test the coating performance. Table 3 shows the coating performance of the floor edge-sealing water-based coatings of Examples 1-3 and Reference Examples 1-3, as well as the coating performance of Reference Example 4. The ethanol resistance test used a 50% ethanol solution by volume. The test process took 1 hour, and the test was observed after waiting for 1 hour. The alkali resistance test used a 50g / L NaHCO3 test solution. The test process took 1 hour, and the test was observed after waiting for 1 hour. The stain resistance test used brewed vinegar (in accordance with national standard GB / T 18187-2000) and green tea water (2g green tea / 250ml boiling water, tested after 5 minutes). The test process took 1 hour, and the test was observed after waiting for 1 hour.

[0069] Table 3. Coating properties of water-based edge-sealing floor coatings of Examples 1-3 and Comparative Examples 1-3, and coating properties of Comparative Example 4

[0070]

[0071] Figure 1 、 2 The figure shows a spraying device for water-based edge-sealing paint for flooring, which is suitable for vacuum edge-sealing spraying of the female tenon of the floor block 100. It can be an independent sprayer connected to the spraying line, or it can be an extension of the tongue-and-groove structure processing equipment, that is, it is set at the end of the tongue-and-groove and lock processing lines such as the four-sided planer and the lock line. The spraying device for water-based edge-sealing paint for flooring includes a vacuum spraying mechanism 200 set at an angle, and the vacuum spraying mechanism 200 is fixedly installed by a frame not shown in the figure. Figure 3 As shown, the vacuum spraying mechanism 200 includes a paint source, a vacuum nozzle assembly 210 connected to a paint source pipeline, a limiting assembly 220 , and a mounting shaft 230 .

[0072] The paint source is a water-based edge-sealing paint for the floor loaded in a paint tank or paint pool in the prior art. A paint pump is placed in the paint source, and the paint pump is connected to the vacuum nozzle assembly through a pipeline, an electromagnetic valve, a flow meter, etc.

[0073] The mounting shaft 230 is mounted on one side of the frame, tilted relative to the surface (i.e., horizontal plane) of the floorboard 100. This side corresponds to the side where the female tenon of the floorboard 100 is located. The mounting shaft 230 is mounted on the frame in a restricted manner, meaning it cannot move or rotate about its axis. To facilitate pipeline layout, the mounting shaft 230 is preferably hollow.

[0074] The vacuum nozzle assembly 210 includes an annular sleeve 211 and a vacuum spraying component 212 mounted through the annular sleeve 211. The annular sleeve 211 is fixedly mounted on the mounting shaft 230 by means of a key fit or bearing. Because the vacuum nozzle assembly 210 is tilted, the annular sleeve 211 has a top located at a higher position and a bottom located at a lower position. The bottom of the annular sleeve 211 has a notch, and the bottom of the notch has a through-hole that communicates with the interior of the mounting shaft 230, allowing circuits and pipelines to pass through the mounting shaft and the annular sleeve 211 and connect to the vacuum spraying component 212.

[0075] The vacuum spraying component 212 is any product of the prior art, for example, including a machine head and a vacuum nozzle. The machine head is embedded in the notch and fixed therein by means of screwing, gluing, etc. The inclination angle of the vacuum nozzle assembly 210 relative to the surface of the floorboard 100 does not need to be specifically limited, but the spraying angle of the vacuum nozzle needs to be limited. Generally speaking, the female tenon includes a retreat portion and a tenon groove portion. The retreat portion is formed by cutting off the upper side surface and the surface, including a retreat surface 101. The tenon groove portion includes a groove top surface 102 connected to the retreat surface 101 and extending into the interior of the floorboard 100, as well as a groove inner side surface 103, a groove bottom surface 104, a groove outer side surface 105, and a support surface 106 connected in sequence. The support surface 106 is connected to the remaining lower side surface 107. Depending on the type of the lock buckle, the groove inner side surface 103 can be a vertical surface or an inclined surface. In this embodiment, an obtuse angle is formed between the groove inner side surface 103 and the groove bottom surface 104. It needs to be defined that the extension line of the axis of the vacuum nozzle passes through the connection between the inner side surface 103 of the groove and the bottom surface 104 of the groove, and preferably, the extension position of the vacuum nozzle is located between the connection between the retreat surface 101 and the top surface 102 of the groove and the connection between the bottom surface 104 and the outer side surface 105 of the groove, so as to ensure that the paint sprayed by the vacuum nozzle has sufficient atomization and dispersion space.

[0076] The limiting assembly 220 includes an upper limiting ring and a lower limiting ring mounted on the mounting shaft 230. Both the upper limiting ring and the lower limiting ring are resin rings capable of undergoing a certain degree of elastic deformation. The upper limiting ring includes an upper limiting cavity 221 with a trumpet-shaped opening. The upper limiting cavity 221 is divided into a first upper limiting cavity 2211 and a second upper limiting cavity 2212 that are coaxial and spaced apart. The first upper limiting cavity 2211 and the second upper limiting cavity 2212 are respectively mounted on the mounting shaft 230 via rotating bearings, and both are capable of rotating relative to the mounting shaft 230. The gap between the first upper limiting cavity 2211 and the second upper limiting cavity 2212 can serve as an upper suction channel. The upper suction component 222 includes an upper fixing ring 2221 that sealingly connects the first upper limiting cavity 2211 and the second upper limiting cavity 2212, an upper through hole formed in the upper fixing ring 2221, and an upper suction pipe 2222 that is sealingly inserted into the upper through hole. The upper retaining ring 2221 is fixedly mounted on the mounting shaft 230 via a key structure or bearing. The upper retaining ring 2221 is a conventional sealing strip, sealingly engaging the first and second upper limit cavities 2211 and 2212, respectively, through ridges. The upper suction pipe 2222 is a conventional plastic tube. One end extends beyond the outer wall of the first upper limit cavity 2211, i.e., the limiting working surface of the first upper limit cavity 2211, and is capable of extending into the withdrawal portion of the female tenon parallel to the withdrawal surface 101, but not below the groove top surface 102. The other end extends into the inner ring of the first upper limit cavity 2211, enabling connection to an external vacuum air source. The vacuum air source is a conventional miniature vacuum air pump, etc. Since the negative pressure required to be generated in the female tenon is extremely low, there are no specific requirements for the type of vacuum air source; a vacuum of -0.01 to 0.03 MPa is sufficient.

[0077] During operation, when the floor panel 100 passes through the vacuum spraying mechanism 200, the outer wall surface of the first part upper limit cavity 2211 (that is, the limiting working surface of the first part upper limit cavity 2211) abuts against the surface of the floor panel 100. When the upper suction pipe 2222 starts to suck, it can suck from its limiting working surface toward the inner side of the ring, thereby forming a negative pressure in the retreat part and the mortise part of the female tenon.

[0078] The lower limiting ring includes a lower limiting cavity 223 with a trumpet-shaped opening. The lower limiting cavity 223 is divided into a first lower limiting cavity 2231 and a second lower limiting cavity 2232, which are coaxial and spaced apart. The first lower limiting cavity 2231 and the second lower limiting cavity 2232 are respectively mounted on the mounting shaft 230 via rotating bearings, and both are capable of rotating relative to the mounting shaft 230. The gap between the first lower limiting cavity 2231 and the second lower limiting cavity 2232 can serve as a lower suction channel. The lower suction component 224 includes a lower fixing ring 2241 that sealingly connects the first lower limiting cavity 2231 and the second lower limiting cavity 2232, a lower through hole defined in the lower fixing ring, and a lower suction pipe 2242 that is sealingly inserted into the lower through hole. The lower retaining ring 2241 is fixedly mounted on the mounting shaft 230 via a key structure or bearing. The lower retaining ring 2241 is a conventional sealing strip, which, through a ridge structure, seals with the first and second lower limit cavities 2231, 2232. The lower suction pipe 2242 is a conventional plastic tube. One end extends beyond the outer wall of the first lower limit cavity 2231, i.e., the limiting working surface of the first lower limit cavity 2231, and is capable of extending parallel to the support surface 106 and into the tenon groove of the female tenon, but not exceeding the position of the outer surface 105 of the groove. The other end extends into the inner ring side of the first lower limit cavity 2231, thereby enabling connection to an external vacuum air source pipeline.

[0079] During operation, when the floor panel 100 passes through the vacuum spraying mechanism 200, the outer wall surface of the first part lower limit cavity 2231 (that is, the limiting working surface of the first part lower limit cavity 2231) abuts against the lower side surface 107 of the floor panel 100. When the lower suction pipe 2242 starts to suck, it can suck from its limiting working surface toward the inner side of the ring, thereby forming a negative pressure in the retreat part and the mortise part of the female tenon.

[0080] When the limiting working surfaces of the upper limiting cavity 2211 of the first part and the limiting working surfaces of the lower limiting cavity 2231 of the first part simultaneously abut the surface and lower side surface 107 of the floor panel 100, the limiting assembly 220 and the vacuum nozzle assembly 210 can cooperate with the female tenon of the floor panel 100 to form a spraying operation chamber. Since the spraying operation chamber of the female tenon is relatively small, if the vacuum nozzle is sprayed onto the female tenon surface at a long distance, paint is likely to escape, resulting in paint waste; if the vacuum nozzle is sprayed at a close distance, it is difficult to spray evenly, affecting the uniformity of the paint film. In the technical solution of this embodiment, the limiting working surface of the upper limiting cavity 2211 of the first part and the limiting working surface of the lower limiting cavity 2231 of the first part simultaneously abut against the surface and lower side surface 107 of the floor block 100, which can prevent the atomized paint from being sprayed onto the surface and side surface of the floor block 100 during spraying by the vacuum spraying component 212. At the same time, an instantaneous negative pressure is formed in the spraying operation cavity of the female tenon, so that the paint is fully atomized and adsorbed on the retreat surface 101, the top surface 102 of the groove, the outer side surface 105 of the groove, the support surface 106, and the lower side surface 107, thereby preventing the paint from being too thickly coated on the inner side surface 103 and the bottom surface 104 of the groove.

[0081] Simplified structure reference of the limiting component 220 Figure 4 As shown, the upper limit ring includes an upper limit cavity 221 with a trumpet-shaped opening, an upper suction channel provided on the cavity wall of the upper limit cavity 221, and an upper suction component 222 sealedly inserted into the upper suction channel; the lower limit ring includes a lower limit cavity 223 with a trumpet-shaped opening, a lower suction channel provided on the cavity wall of the lower limit cavity 223, and a lower suction component 224 sealedly inserted into the lower suction channel. In this embodiment, the upper limit ring and the lower limit ring are both fixedly mounted on the mounting shaft 230, and the upper suction channel and the lower suction channel are through holes provided on the cavity walls of the upper limit cavity 221 and the lower limit cavity 223, respectively. The structure of this embodiment is relatively simple, but the outer walls of the upper limit cavity 221 and the lower limit cavity 223 rub against the surface of the floor panel 100 and are prone to wear.

[0082] Example 4: The water-based edge-sealing paint for the floor obtained in Example 1 is sprayed on the female joints of the wooden floor using the above-mentioned spraying equipment for the water-based edge-sealing paint for the floor.

[0083] Comparative Example 5: The water-based edge sealing coating for the floor obtained in Example 1 was sprayed on the female joints of the wooden floor using the vacuum spraying equipment of the prior art.

[0084] Table 4 shows the coating thickness at various locations of the mother tenon obtained by the methods of Examples 4 and 5.

[0085] Table 4. Coating thickness of each part of the mother tenon obtained by the method of Examples 4 and 5 / mm

[0086] Example Retreat side Groove top surface Inner side of the groove Groove bottom Outer side of the groove Support surface Example 4 0.03 0.03 0.03 0.03 0.03 0.03 Comparative Example 5 0.01 0.01 0.05 0.05 0.01 0.01

[0087] The above description is intended to be illustrative and not limiting. Many embodiments and applications beyond the examples provided will be apparent to those skilled in the art upon reading the above description. Therefore, the scope of the present teachings should not be determined with reference to the above description, but rather with reference to the appended claims and the full scope of equivalents to which such claims are entitled. For the purpose of completeness, all articles and references, including disclosures of patent applications and publications, are incorporated herein by reference. The omission of any aspect of the subject matter disclosed herein from the preceding claims is not a disclaimer of such subject matter, nor should it be considered that the applicants did not consider such subject matter to be part of the disclosed subject matter.

Claims

1. A spraying device for water-based edge-sealing paint for flooring, characterized in that: It comprises a vacuum spraying mechanism arranged at an angle, the vacuum spraying mechanism comprising a limit assembly, a vacuum nozzle assembly, a paint source connected to the vacuum nozzle assembly pipeline, and a mounting shaft; the mounting shaft is fixedly mounted on the frame, and the limit assembly can rotate relative to the mounting shaft; the limit assembly comprises an upper limit ring and a lower limit ring mounted on the mounting shaft, the upper limit ring can suck from the inner side of its limit working surface of the ring, and the lower limit ring can suck from the inner side of its limit working surface of the ring; the vacuum nozzle assembly is fixedly mounted on the mounting shaft, the vacuum nozzle assembly is located between the upper limit ring and the lower limit ring, and abuts against the upper limit ring and the lower limit ring; the limit assembly and the vacuum nozzle assembly can cooperate with the female tenon of the floor block to form a spraying operation chamber.

2. The spraying equipment for edge-sealing water-based paint for flooring according to claim 1, characterized in that: The upper limit ring includes an upper limit cavity with a trumpet opening, an upper suction channel provided on the cavity wall of the upper limit cavity, and an upper suction component sealingly inserted in the upper suction channel. The outer wall of the upper limit cavity abuts and cooperates with the surface of the floor block, and the upper suction component is connected to the vacuum air source pipeline; the lower limit ring includes a lower limit cavity with a trumpet opening, a lower suction channel provided on the cavity wall of the lower limit cavity, and a lower suction component sealingly inserted in the lower suction channel. The outer wall of the lower limit cavity abuts and cooperates with the side of the floor block, and the lower suction component is connected to the vacuum air source pipeline.

3. The spraying equipment for edge-sealing water-based paint for flooring according to claim 2, characterized in that: The upper limit cavity is divided into a first part upper limit cavity and a second part upper limit cavity which are coaxial and set with a gap, the gap is the upper suction channel, and the upper suction component includes an upper fixing ring which is sealingly connected to the first part upper limit cavity and the second part upper limit cavity, an upper through hole provided on the upper fixing ring, and an upper suction pipe which is sealingly inserted into the upper through hole; the lower limit cavity is divided into a first part lower limit cavity and a second part lower limit cavity which are coaxial and set with a gap, the gap is the lower suction channel, and the lower suction component includes a lower fixing ring which is sealingly connected to the first part lower limit cavity and the second part lower limit cavity, a lower through hole provided on the lower fixing ring, and a lower suction pipe which is sealingly inserted into the lower through hole.

4. The spraying equipment for edge-sealing water-based paint for flooring according to claim 1, characterized in that: The extension line of the axis of the vacuum nozzle of the vacuum nozzle assembly passes through the connection between the inner side surface of the groove of the female tenon and the bottom surface of the groove.

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