Environment-friendly solventless coating and preparation method thereof

Abstract

The invention relates to the technical field of coating preparation, and discloses an environment-friendly solvent-free coating and a preparation method thereof. The raw materials comprise, by mass, 40-70% of polyester resin, 3-8% of highlight barium sulfate, 5-10% of precipitated barium sulfate, 6-12% of calcium carbonate, 4-12% of hydroxyalkylamide, 15-20% of a pigment filler, 4-6% of nano-silica, 4-6% of hollow glass beads, 0.05-0.2% of a curing inhibitor, 0.1-0.5% of a lubricant, 0.8-3% of a leveling agent, 0.8-1% of benzoin, and 0.8-2% of an anti-ultraviolet absorbent. The pigment filler comprises zinc oxide and aluminum silicate fiber. Raw materials are evenly scattered into the stirring barrel twice through the spiral scattering assembly, material accumulation is avoided, the mixing uniformity is improved, the V-shaped elastic stirring piece can deform in the stirring process, caked raw materials are squeezed to be loosened, the stirring piece is formed by hinging two stirring plates, the inner side of the stirring piece is provided with a squeezing structure, the squeezing effect is optimized, the stirring plates are provided with sieve holes, and the stirring effect is improved. Raw materials can be cut, accumulation is prevented, and the stirring efficiency and uniformity are improved.

Description

Technical Field

[0001] The present invention relates to the technical field of coating preparation, and in particular to an environmentally friendly solvent-free coating and a preparation method thereof. Background Art

[0002] Powder coating is an environmentally friendly solvent-free coating. It exists in fine powder form. No solvent is added during the production process, which fundamentally avoids the environmental and safety problems caused by solvent volatilization. During construction, the powder coating is transferred to the surface of the coated object in powder form, and forms a uniform and dense coating film through baking, melting and solidification. It not only has excellent decorative and protective properties, but also, due to its powdery physical form, has the advantages of less space occupation, less leakage, less volatility, and less flammability and explosion compared to traditional solvent-based coatings during storage and transportation. This reduces storage and transportation costs and risks, while also reducing potential pollution to the environment. In the preparation process of the coating, all raw materials must first be dried to remove the moisture therein. Then, according to the formula ratio of the powder coating, the main raw materials are put into the mixer for pre-mixing. After the pre-mixing is completed, the remaining raw materials are added to the pre-mixed materials for secondary mixing. The mixed materials are sent to the extruder for kneading. The screw shearing action of the extruder melts and shears the materials, so that the components are fully mixed in the high-temperature molten state and form a uniform melt. Then, the molten material extruded by the extruder is conveyed to the tablet press. The roller pressing action of the tablet press squeezes the molten material into flakes for subsequent cooling and crushing. After the flake material is cooled to room temperature, it is first coarsely crushed to break it into smaller particles, and then ground and finely crushed to obtain powder that meets the particle size requirements. Finally, the crushed powder is passed through a grading and screening equipment for particle size classification to remove unqualified coarse particles and fine powder to ensure that the particle size distribution of the coating powder meets the standard requirements. After strict testing and processing, powder coating products that meet quality standards are produced. In the process of mixing paint raw materials, a two-step mixing process is adopted, that is, the main raw materials are first mixed in a mixer, and then the remaining raw materials are poured into the mixer at one time for secondary mixing. However, in the secondary mixing stage, all the remaining raw materials are poured into the mixer at one time, which is prone to insufficient mixing. Because pouring a large amount of remaining raw materials at one time will cause instantaneous accumulation of materials in the mixer, making the distribution of materials in the mixer uneven, the material concentration in some areas is too high, and the materials in other areas are relatively thin.

[0003] To solve the above problems, this application proposes an environmentally friendly solvent-free coating and a preparation method thereof. Summary of the Invention

[0004] The present invention provides an environmentally friendly solvent-free coating and a preparation method thereof, which solves the problem in the related art that in the secondary mixing stage, all the remaining raw materials are poured into the mixer at one time, resulting in insufficient stirring.

[0005] The present invention provides an environmentally friendly solvent-free coating comprising the following raw materials, which are expressed in percentage by mass: Polyester resin 40-70%, high gloss barium sulfate 3-8%, precipitated barium sulfate 5-10%, calcium carbonate 6-12%, hydroxyalkylamide 4-12%, pigments and fillers 15-20%, nano-silica 4-6%, hollow glass microspheres 4-6%, curing inhibitor 0.05-0.2%, lubricant 0.1-0.5%, leveling agent 0.8-3%, benzoin 0.8-1%, anti-UV absorber 0.8-2%; The pigments and fillers include zinc oxide and aluminum silicate fibers.

[0006] A method for preparing an environmentally friendly solvent-free coating, using the above-mentioned environmentally friendly solvent-free coating, comprises the following steps: Step 1: Drying: Dry all raw materials before mixing; Step 2: Mixing: The main raw materials, polyester resin, high-gloss barium sulfate, precipitated barium sulfate, calcium carbonate and hollow glass microspheres are put into a blender for pre-mixing. After the pre-mixing is completed, the remaining raw materials are added to the pre-mixed materials for secondary mixing; Step 3: Melt extrusion: The mixed materials are sent to the extruder for mixing, and the materials are melted and sheared by the shearing action of the screw of the extruder; Step 4: Cooling and tableting: The molten material extruded from the extruder is conveyed to the tablet press, and the molten material is squeezed into thin sheets by the roller pressing action of the tablet press, and then cooled to room temperature; Step 5: Coarsely crush the flaky material into smaller particles, and then grind them into fine particles; Step 6. Finished product: The crushed powder is passed through a grading and screening device for particle size classification to remove unqualified coarse particles and fine powder, and then the powder product is obtained after testing.

[0007] As a further optimization scheme of the present invention, the mixer includes a mixing drum, a spiral spreading assembly, a rotating tube, a V-shaped elastic stirring member, a driving member and a hot air supply member, the spiral spreading assembly is installed on the top of the mixing drum, the rotating tube is vertically arranged in the mixing drum, a plurality of circumferentially arranged V-shaped elastic stirring members are installed on the rotating tube, an exhaust valve that cooperates with the V-shaped elastic stirring member is installed on the inner wall of the mixing drum, a hot air nozzle is installed on the rotating tube, and the hot air supply member is used to guide hot air into the rotating tube and discharge it through the hot air nozzle; The rotating tube is driven by the driving member to drive the spiral spreading assembly and the V-shaped elastic stirring member to rotate simultaneously. When the spiral spreading assembly rotates, the material is thrown into the mixing drum in a spiral shape. When the V-shaped elastic stirring member rotates, it stirs the material and when it passes through the semi-arc convex position and collides with it, it deforms and squeezes the material.

[0008] As a further optimization scheme of the present invention, the V-shaped elastic stirring member includes a first stirring plate, a second stirring plate and an arc-shaped elastic sheet. The first stirring plate and the second stirring plate are hinged to each other to form a V-shaped structure. The first stirring plate is fixedly connected to the rotating tube. The semi-arc protrusion corresponds to the rotation path of the second stirring plate. The arc-shaped elastic sheet is connected between the first stirring plate and the second stirring plate. Mesh holes are provided on the first stirring plate and the second stirring plate.

[0009] As a further optimization solution of the present invention, an extrusion structure is installed on the inner side of the first stirring plate and the second stirring plate; The extrusion structure includes multiple groups of extrusion rods, and the length and diameter of each group of extrusion rods increase in sequence from the adjacent ends of the first stirring plate and the second stirring plate to the distant ends.

[0010] As a further optimization scheme of the present invention, the spiral spreading assembly includes a loading seat, a feeding barrel and a spiral spreading piece. The loading seat is installed on the top of the mixing barrel. A through assembly channel is provided in the loading seat. The rotating tube rotates through the bottom of the feeding barrel and is installed with a push plate located in the feeding barrel. The top of the feeding barrel is covered with an end cover. The spiral spreading piece is fixedly mounted on the rotating tube and is located in the assembly channel. The bottom of the feeding barrel is provided with an eccentrically arranged drop port that is connected to the spiral spreading piece.

[0011] As a further optimization scheme of the present invention, the spiral spreading member includes a spreading barrel, which is fixedly mounted on the rotating tube and located in the assembly channel. The drop-out port is connected to the spreading barrel, and the bottom of the spreading barrel is symmetrically connected to two spreading pipes located in the mixing barrel, and the spreading pipes are inclined outward from the bottom of the spreading barrel.

[0012] As a further optimization scheme of the present invention, the hot air supply component includes a rotary joint, a hot air pipe and a hot air blower. The rotary joint is installed at the bottom of the mixing drum. The bottom end of the rotating pipe rotates through the bottom of the mixing drum and is connected to the rotating air outlet end of the rotary joint. The air inlet end of the rotary joint is connected to the hot air blower through the hot air pipe.

[0013] As a further optimization scheme of the present invention, the driving member includes a driven gear, a driving gear and a motor. The driven gear is fixedly sleeved on the bottom end of the rotating tube and is located between the mixing drum and the rotary joint. The motor is installed at the bottom of the mixing drum, and the output end of the motor is connected to the driving gear that meshes with the driven gear.

[0014] As a further optimization solution of the present invention, an exhaust valve is connected to the outer periphery of the mixing drum, a discharge pipe is connected to the bottom of the mixing drum, and a control valve is installed on the discharge pipe.

[0015] The above technical solution of the present invention has the following beneficial technical effects: 1. When mixing raw materials, the present invention first pours the main raw material into the spiral spreading assembly, and then drives the rotating tube to rotate the spiral spreading assembly through the driving member, and the main raw material is spirally scattered into the mixing drum, and the main raw material is pre-mixed and stirred by the V-shaped elastic stirring member on the rotating tube. After the pre-mixing is completed, the remaining raw material is poured into the spiral spreading assembly, and the spiral spreading assembly is used to sprinkle the remaining raw material again in a spiral shape into the mixing drum to mix with the main raw material. The present invention uses the spiral spreading assembly to evenly sprinkle the main raw material and the remaining raw material into the mixing drum in two spiral shapes, avoiding the problems of instantaneous accumulation and uneven distribution of materials caused by traditional one-time pouring. This step-by-step and uniform spreading method allows the raw materials to be more evenly distributed in the mixing drum from the beginning, providing a good foundation for subsequent mixing and stirring, reducing the phenomenon of local excessive concentration or thinness, thereby improving the overall uniformity of the mixed raw materials, and providing a strong guarantee for the performance consistency of the coating; 2. In the process of mixing and stirring the raw materials by the V-shaped elastic stirring piece on the rotating tube of the present invention, when the V-shaped elastic stirring piece passes through the semi-arc convex position of the inner wall of the mixing drum, it can be deformed, squeezing the raw materials agglomerated during stirring to loosen them. Since the rotating tube can drive the V-shaped elastic stirring piece to rotate continuously, the V-shaped elastic stirring piece can be deformed under the reaction force each time it passes through the semi-arc convex position, and then return to its original position. This design can enable the V-shaped elastic stirring piece to continuously deform and recover, thereby achieving reciprocating extrusion of the agglomerated raw materials, so that the agglomerated materials are loosened. This design can not only effectively handle agglomerated materials and avoid insufficient mixing caused by agglomeration, but also ensure that the agglomerated materials are fully loosened through continuous deformation and recovery, further improving the mixing effect, ensuring uniform mixing of the coating raw materials, and improving the quality and performance of the coating. 3. The V-shaped elastic stirring member of the present invention is formed by hingedly connecting the first stirring plate and the second stirring plate. When the rotating tube drives the V-shaped elastic stirring member to rotate and the second stirring plate passes through the semi-arc convex position, under the reaction force, the angle between the second stirring plate and the first stirring plate becomes smaller, and the arc-shaped elastic sheet between the first stirring plate and the second stirring plate is compressed and deformed. When the angle between the first stirring plate and the second stirring plate changes, the raw materials close to the narrow angle will be squeezed first, and as the squeezing process progresses, the materials will be squeezed to the extreme and will hinder the two plates from getting closer. This also results in excessive squeezing occurring closer to the narrow angle and the further away from the narrow angle. The squeezing degree is not enough at the corners, so an squeezing structure is set on the inner side of the first stirring plate and the second stirring plate. The squeezing structure consists of multiple groups of squeezing rods. The length and diameter of each group of squeezing rods increase in sequence from the narrow angle between the first stirring plate and the second stirring plate to the position away from the narrow angle. This structural design can make the thin and short squeezing rods close to the narrow angle pierce the raw materials and give priority to squeezing the raw materials at the narrow angle position. The thick and long squeezing rods away from the narrow angle make up for the problem of insufficient squeezing degree, thereby ensuring that the raw materials can be evenly and appropriately squeezed during the entire stirring process, further optimizing the mixing effect, and improving the dispersion and uniformity of the raw materials; 4. The present invention provides sieve holes on both the first stirring plate and the second stirring plate. When the rotating tube drives the first stirring plate and the second stirring plate to rotate and stir the raw materials, the sieve holes on the first stirring plate and the second stirring plate can cut the raw materials, and the sieve holes can also prevent the raw materials from accumulating at the narrow angle between the first stirring plate and the second stirring plate. The cutting effect helps to further refine the raw material particles and make the raw materials more dispersed during the stirring process, while the anti-accumulation function avoids the problem of affecting the stirring efficiency and mixing uniformity due to the accumulation of raw materials in local areas. Through this design, the stirring efficiency is improved, and the fluidity and uniformity of the raw materials in the mixing drum are also better guaranteed, thereby improving the efficiency and quality of the entire mixing process; 5. When the raw materials are mixed and stirred, the present invention can guide the hot air into the rotating tube through the hot air supply part, and then blow the hot air toward the raw materials in the stirring process through the hot air nozzle on the rotating tube, which can not only loosen the raw materials, but also heat the raw materials. Heating the raw materials can not only remove the undried moisture in the raw materials, but also preheat them to prepare for the next step of melt extrusion. This pretreatment method can improve the efficiency and effect of subsequent processes, reduce production problems caused by insufficient moisture or temperature of the raw materials, and improve the stability of the entire coating production process and product quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 The present invention provides a flow chart of a method for preparing an environmentally friendly solvent-free coating.

[0017] Figure 2 It is a structural schematic diagram of the mixing drum of the present invention.

[0018] Figure 3 Schematic diagram of the bottom structure of the mixing drum of the present invention.

[0019] Figure 4 This is an internal cross-sectional view of the mixing drum of the present invention.

[0020] Figure 5 Schematic diagram of the internal structure of the mixing drum of the present invention.

[0021] Figure 6 It is a schematic structural diagram of the rotating tube and the V-shaped elastic stirring member of the present invention.

[0022] Figure 7 It is a structural schematic diagram of the V-shaped elastic stirring element of the present invention.

[0023] Figure 8 It is a structural schematic diagram of the spiral spreading assembly of the present invention.

[0024] Figure 9 It is a structural schematic diagram of the driving component and the hot air supply component of the present invention.

[0025] Figure numerals: 1. mixing drum; 101. semi-arc protrusion; 102. exhaust valve; 103. discharge pipe; 104. control valve; 2. spiral spreading assembly; 21. loading seat; 22. feeding barrel; 221. drop port; 222. end cover; 23. spiral spreading member; 231. spreading barrel; 232. spreading pipe; 3. rotating pipe; 31. hot air nozzle; 32. pushing plate; 4. V-shaped elastic stirring member; 41. first stirring plate; 42. second stirring plate; 43. arc-shaped elastic sheet; 44. sieve hole; 45. extrusion structure; 451. extrusion rod; 5. driving member; 51. driven gear; 52. driving gear; 53. motor; 6. hot air supply member; 61. rotary joint; 62. hot air pipe; 63. hot air blower. DETAILED DESCRIPTION

[0026] To make the objectives, technical solutions, and advantages of the present invention more clearly understood, the present invention will be further described in detail below in conjunction with specific embodiments and with reference to the accompanying drawings. It should be understood that these descriptions are merely exemplary and are not intended to limit the scope of the present invention. In addition, in the following description, descriptions of well-known structures and technologies are omitted to avoid unnecessary confusion of the concepts of the present invention.

[0027] like Figure 1-9 As shown, the environmentally friendly solvent-free coating proposed by the present invention includes the following raw materials, which are expressed in percentage by mass: Polyester resin 40-70%, high gloss barium sulfate 3-8%, precipitated barium sulfate 5-10%, calcium carbonate 6-12%, hydroxyalkylamide 4-12%, pigments and fillers 15-20%, nano-silica 4-6%, hollow glass microspheres 4-6%, curing inhibitor 0.05-0.2%, lubricant 0.1-0.5%, leveling agent 0.8-3%, benzoin 0.8-1%, anti-UV absorber 0.8-2%; Pigments and fillers include zinc oxide and aluminum silicate fibers.

[0028] When preparing environmentally friendly solvent-free coatings, each raw material is accurately weighed according to the mass percentage. Polyester resin is the main film-forming substance, which determines the basic properties of the coating, such as the hardness and flexibility after film formation. High-gloss barium sulfate and precipitated barium sulfate can improve the hiding power and gloss of the coating, are evenly dispersed in the coating, fill in the gaps in the film-forming substances, and enhance the density of the coating. Calcium carbonate can improve the processing performance and physical properties of the coating and reduce costs. Hydroxyalkylamide is used as a curing agent and reacts with polyester resin under certain conditions to form a strong coating film. Zinc oxide in the pigment filler has antibacterial and mildew-proof effects. Aluminum silicate fiber can enhance the mechanical strength of the coating. The two work together to improve the comprehensive performance of the coating. Nano-silica can improve the coating The wear resistance, scratch resistance and weather resistance of the material are improved. Its nano-scale particles are evenly dispersed in the coating system, which enhances the microstructural stability of the coating. The hollow glass microspheres can reduce the weight of the coating and improve the thermal insulation performance of the coating. The curing inhibitor controls the curing speed of the coating to prevent premature curing during the preparation and storage process. The lubricant improves the fluidity of the coating, making it easier to apply the coating evenly during construction. The leveling agent ensures that the coating forms a flat and smooth surface during the film formation process. Benzoin is used to eliminate bubbles generated by the coating during the curing process. The anti-UV absorber can effectively absorb ultraviolet rays, improve the weather resistance of the coating, and extend the service life of the coating. By controlling the proportion of each raw material, it is ensured that the coating has good environmental performance, physical properties and chemical properties.

[0029] like Figure 1 As shown, a method for preparing an environmentally friendly solvent-free coating, using the above-mentioned environmentally friendly solvent-free coating, comprises the following steps: Step 1: Drying: Dry all raw materials before mixing; Step 2: Mixing: The main raw materials, polyester resin, high-gloss barium sulfate, precipitated barium sulfate, calcium carbonate and hollow glass microspheres are put into a blender for pre-mixing. After the pre-mixing is completed, the remaining raw materials are added to the pre-mixed materials for secondary mixing; Step 3: Melt extrusion: The mixed materials are sent to the extruder for mixing, and the materials are melted and sheared by the shearing action of the screw of the extruder; Step 4: Cooling and tableting: The molten material extruded from the extruder is conveyed to the tablet press, and the molten material is squeezed into thin sheets by the roller pressing action of the tablet press, and then cooled to room temperature; Step 5: Coarsely crush the flaky material into smaller particles, and then grind them into fine particles; Step 6. Finished product: The crushed powder is passed through a grading and screening device for particle size classification to remove unqualified coarse particles and fine powder, and then the powder product is obtained after testing.

[0030] like Figure 2 、 Figure 3 、 Figure 4 、 Figure 5 and Figure 6 As shown, in this embodiment, the mixer includes a mixing drum 1, a spiral spreading assembly 2, a rotating tube 3, a V-shaped elastic stirring member 4, a driving member 5 and a hot air supply member 6. The spiral spreading assembly 2 is installed on the top of the mixing drum 1, and the rotating tube 3 is vertically arranged in the mixing drum 1. A plurality of circumferentially arranged V-shaped elastic stirring members 4 are installed on the rotating tube 3. An exhaust valve 102 that cooperates with the V-shaped elastic stirring member 4 is installed on the inner wall of the mixing drum 1. A hot air nozzle 31 is installed on the rotating tube 3. The hot air supply member 6 is used to guide hot air into the rotating tube 3 and discharge it through the hot air nozzle 31. The rotating tube 3 is driven by the driving member 5 to drive the spiral spreading component 2 and the V-shaped elastic stirring member 4 to rotate simultaneously. When the spiral spreading component 2 rotates, it throws the material into the mixing drum 1 in a spiral shape. When the V-shaped elastic stirring member 4 rotates, it stirs the material and when it passes through the semi-arc protrusion 101 and collides with it, it deforms and squeezes the material.

[0031] When the raw materials are mixed, the driving member 5 works to drive the rotating tube 3 to rotate. The rotation of the rotating tube 3 drives the spiral spreading component 2 and the V-shaped elastic stirring member 4 to rotate synchronously. When the spiral spreading component 2 rotates, the material is thrown into the mixing drum 1 in a spiral shape, so that the material is evenly distributed in the mixing drum 1 to avoid concentrated accumulation. The V-shaped elastic stirring member 4 stirs the material during the rotation process. When the V-shaped elastic stirring member 4 passes through the semi-arc protrusion 101 on the inner wall of the mixing drum 1, it is subjected to the reaction force of the semi-arc protrusion 101, and the V-shaped elastic stirring member 4 is deformed. , the agglomerated raw materials in stirring are squeezed to loosen them. During the stirring process of the raw materials, the hot air nozzle 31 on the rotating tube 3, under the action of the hot air supply part 6, guides the hot air into the raw materials in the mixing drum 1. On the one hand, the hot air loosens the raw materials, and on the other hand, it heats the raw materials, removes residual moisture and preheats them, preparing for subsequent melt extrusion, thereby improving the efficiency and quality of subsequent processes. This structural design realizes the functions of uniform material spreading, efficient stirring, agglomeration treatment and raw material preheating, effectively improving the quality and efficiency of raw material mixing.

[0032] like Figure 5 、 Figure 6 and Figure 7 As shown, in this embodiment, the V-shaped elastic stirring member 4 includes a first stirring plate 41, a second stirring plate 42 and an arc-shaped elastic sheet 43. The first stirring plate 41 and the second stirring plate 42 are hinged to each other to form a V-shaped structure. The first stirring plate 41 is fixedly connected to the rotating tube 3, and the semi-arc protrusion 101 corresponds to the rotation path of the second stirring plate 42. The arc-shaped elastic sheet 43 is connected between the first stirring plate 41 and the second stirring plate 42. Sieve holes 44 are provided on the first stirring plate 41 and the second stirring plate 42.

[0033] When the rotating tube 3 drives the V-shaped elastic stirring member 4 to rotate, the second stirring plate 42 is subjected to the reaction force of the semi-arc protrusion 101 when passing the position of the semi-arc protrusion 101, and the angle between the second stirring plate 42 and the first stirring plate 41 becomes smaller, and the arc-shaped elastic sheet 43 connected between the two is compressed and deformed. At this time, the raw materials between the first stirring plate 41 and the second stirring plate 42 are squeezed, causing the agglomerated raw materials to loosen. At the same time, the sieve holes 44 opened on the first stirring plate 41 and the second stirring plate 42 have a cutting effect on the raw materials during the stirring process, further refining the larger raw material particles and improving the dispersion of the raw materials. The sieve holes 44 can also prevent the raw materials from accumulating at the narrow angle position between the first stirring plate 41 and the second stirring plate 42, thereby ensuring the uniformity of the stirring and avoiding the influence of local raw material accumulation on the stirring efficiency and mixing quality, thereby improving the effect of the entire stirring process and ensuring that the raw materials are mixed more evenly.

[0034] like Figure 7 As shown, in this embodiment, an extrusion structure 45 is installed on the inner side of the first stirring plate 41 and the second stirring plate 42; The extrusion structure 45 includes a plurality of extrusion rods 451 . The length and diameter of each extrusion rod 451 increase from the adjacent ends of the first stirring plate 41 and the second stirring plate 42 to the distal ends.

[0035] In the process of the V-shaped elastic stirring member 4 stirring the raw materials, as the angle between the first stirring plate 41 and the second stirring plate 42 changes, the raw materials near the narrow angle will be squeezed first, and the squeezing degree at the position away from the narrow angle is insufficient. A plurality of extrusion rods 451 are installed on the inner side of the first stirring plate 41 and the second stirring plate 42. The length and diameter of each group of extrusion rods 451 increase successively from the narrow angle to the position away from the narrow angle. When the V-shaped elastic stirring member 4 rotates to extrude the raw materials, the thin and short extrusion rods 451 near the narrow angle can pierce the raw materials first, and give priority to squeezing the raw materials at the narrow angle position, while the thick and long extrusion rods 451 away from the narrow angle make up for the problem of insufficient squeezing degree away from the narrow angle, so that the raw materials can be evenly and appropriately extruded during the entire stirring process, further optimizing the mixing effect, improving the dispersion and uniformity of the raw materials, and ensuring the mixing quality of the coating.

[0036] like Figure 4 and Figure 8 As shown, in this embodiment, the spiral spreading assembly 2 includes a loading seat 21, a feeding barrel 22 and a spiral spreading piece 23. The loading seat 21 is installed on the top of the mixing barrel 1. A through assembly channel is provided in the loading seat 21. The rotating tube 3 rotates through the bottom of the feeding barrel 22 and is installed with a pushing plate 32 located in the feeding barrel 22. The top of the feeding barrel 22 is covered with an end cover 222. The spiral spreading piece 23 is fixedly mounted on the rotating tube 3 and is located in the assembly channel. The bottom of the feeding barrel 22 is provided with an eccentrically arranged drop port 221 that is connected to the spiral spreading piece 23.

[0037] During the raw material mixing process, the end cover 222 on the feed barrel 22 can be opened, and the raw materials can be poured into it, and then the end cover 222 can be closed. When the rotating tube 3 rotates, the pushing plate 32 can be driven to rotate in the feed barrel 22, and the material in the feed barrel 22 is pushed to the drop port 221. The material enters the spiral spreading member 23 through the drop port 221. The spiral spreading member 23 is fixedly mounted on the rotating tube 3 and rotates with the rotating tube 3 to scatter the material in a spiral shape into the mixing drum 1. This structural design can realize the quantitative transportation and uniform scattering of materials, ensure that the materials are evenly distributed in the mixing drum 1, provide favorable conditions for subsequent stirring and mixing, avoid the uneven distribution problem caused by concentrated pouring of materials, and improve the mixing efficiency and quality.

[0038] like Figure 8 As shown, in this embodiment, the spiral spreading member 23 includes a spreading barrel 231, which is fixedly mounted on the rotating tube 3 and located in the assembly channel. The drop-out port 221 is connected to the spreading barrel 231, and the bottom of the spreading barrel 231 is symmetrically connected to two spreading pipes 232 located in the mixing barrel 1, and the spreading pipes 232 are inclined outward from the bottom of the spreading barrel 231.

[0039] When the rotating tube 3 drives the spiral spreading member 23 to rotate, the spreading barrel 231 collects the material entering from the drop port 221. Since the spreading pipe 232 is inclined outward from the bottom of the spreading barrel 231, under the action of centrifugal force, the material is thrown out along the inclined direction of the spreading pipe 232 and is evenly dispersed into the mixing barrel 1 in a spiral shape. The spreading pipe 232 is symmetrically arranged, which makes the distribution of the material in the mixing barrel 1 more uniform, further improves the uniformity of the spreading, ensures that the raw materials can be fully mixed in the subsequent stirring process, avoids local concentration differences, and improves the overall effect of the coating raw material mixing.

[0040] like Figure 9 As shown, in this embodiment, the hot air supply component 6 includes a rotary joint 61, a hot air pipe 62 and a hot air blower 63. The rotary joint 61 is installed at the bottom of the mixing drum 1. The bottom end of the rotating tube 3 rotates through the bottom of the mixing drum 1 and is connected to the rotating air outlet end of the rotary joint 61. The air inlet end of the rotary joint 61 is connected to the hot air blower 63 through the hot air pipe 62.

[0041] The hot air blower 63 generates hot air, which is transported to the rotary joint 61 through the hot air pipe 62. The hot air can enter the rotary tube 3 through the rotary joint 61, and then be discharged through the hot air nozzle 31 on the rotary tube 3 and blown toward the raw materials in the mixing drum 1. During the raw material mixing process, the hot air can, on the one hand, loosen the agglomerated raw materials to facilitate mixing and stirring. On the other hand, it heats the raw materials and removes the undried moisture in the raw materials. At the same time, it preheats the raw materials to prepare for the subsequent melt extrusion process, thereby improving the efficiency and stability of the subsequent process and reducing production defects caused by raw material humidity or temperature problems.

[0042] like Figure 9 As shown, in this embodiment, the driving member 5 includes a driven gear 51, a driving gear 52 and a motor 53. The driven gear 51 is fixedly mounted on the bottom end of the rotating tube 3 and is located between the mixing drum 1 and the rotary joint 61. The motor 53 is installed at the bottom of the mixing drum 1, and the output end of the motor 53 is connected to the driving gear 52 meshing with the driven gear 51.

[0043] After the motor 53 is started as a power source, its output end drives the driving gear 52 to rotate, and the driving gear 52 engages with the driven gear 51. The driven gear 51 is fixedly sleeved on the bottom end of the rotating tube 3. Under the drive of the driving gear 52, the driven gear 51 drives the rotating tube 3 to rotate. The rotation of the rotating tube 3 then drives the spiral spreading assembly 2 and the V-shaped elastic stirring member 4 to rotate synchronously, thereby achieving uniform spreading and stirring of the material.

[0044] like Figure 3 As shown, in this embodiment, an exhaust valve 102 is connected to the outer periphery of the mixing drum 1 , a discharge pipe 103 is connected to the bottom of the mixing drum 1 , and a control valve 104 is installed on the discharge pipe 103 .

[0045] During the mixing process, hot air needs to be blown to the raw materials in the mixing drum 1. The exhaust valve 102 can discharge excess gas in time to maintain the stable air pressure in the mixing drum 1 and avoid excessive air pressure affecting the mixing effect. When the mixing is completed, the control valve 104 on the discharge pipe 103 is opened, and the mixed material is discharged from the mixing drum 1 through the discharge pipe 103, which is convenient for subsequent melt extrusion and other processes.

[0046] The specific working principle of the present invention is as follows: According to the coating formula, various raw materials such as polyester resin, high-gloss barium sulfate, etc. are weighed according to mass percentage, the end cap 222 of the feeding cylinder 22 is opened, and the main raw materials of polyester resin, high-gloss barium sulfate, precipitated barium sulfate, calcium carbonate and hollow glass microspheres are poured into it, and then the end cap 222 is closed; The motor 53 is started, and its output end drives the driving gear 52 to rotate. The driven gear 51 meshing with the driving gear 52 drives the rotating tube 3 to rotate. The rotation of the rotating tube 3 drives the push plate 32 to rotate in the feeding barrel 22, pushing the main raw materials to the drop opening 221. The raw materials enter the spiral spreading member 23 through the drop opening 221. The spreading tube 231 in the spiral spreading member 23 rotates with the rotating tube 3. Under the action of centrifugal force, the material is evenly scattered in a spiral shape along the outward-inclined spreading tube 232 into the mixing drum 1. At the same time, the rotating tube 3 drives the V-shaped elastic stirring members 4 arranged circumferentially thereon to rotate, pre-mixing and stirring the main raw materials entering the mixing drum 1; After the pre-mixing of the main raw materials is completed, the remaining raw materials are poured into the feeding barrel 22, and the above-mentioned spreading process is repeated to fully mix the remaining raw materials with the pre-mixed main raw materials in the mixing barrel 1. During the mixing process, when the second stirring plate 42 of the V-shaped elastic stirring member 4 passes through the semi-arc protrusion 101 on the inner wall of the mixing barrel 1, it is subjected to a reaction force, and the angle between the second stirring plate 42 and the first stirring plate 41 becomes smaller, and the arc-shaped elastic sheet 43 connecting the two is compressed and deformed, thereby squeezing the raw materials between the two plates to loosen the agglomerated raw materials. The sieve holes 44 opened on the first stirring plate 41 and the second stirring plate 42 have a cutting effect on the raw materials during mixing, and refine the raw material particles, while preventing the raw materials from accumulating in narrow angle positions, thereby improving the mixing uniformity and efficiency. In addition, the extrusion structure 45 installed on the inner side of the first stirring plate 41 and the second stirring plate 42 has multiple groups of extrusion rods 451 whose length and diameter increase successively from the narrow angle to the position away from the narrow angle, which can ensure that the raw materials are evenly and appropriately extruded during the mixing process, further optimizing the mixing effect; The hot air generated by the hot air blower 63 is transported to the rotary joint 61 through the hot air pipe 62, then enters the rotary tube 3 through the rotary joint 61, and finally blows toward the stirring raw materials through the hot air nozzle 31 on the rotary tube 3. On the one hand, the hot air loosens the agglomerated raw materials to facilitate stirring and mixing. On the other hand, it heats the raw materials to remove undried moisture and preheat the raw materials to prepare for the subsequent melt extrusion process, thereby improving the efficiency and stability of the subsequent process. During the stirring process, the exhaust valve 102 discharges the excess gas in the mixing drum 1 in time to maintain the air pressure in the mixing drum 1 stable. After the mixing is completed, the control valve 104 on the discharge pipe 103 is opened, and the mixed material is discharged from the mixing drum 1 through the discharge pipe 103 and enters the extruder for melt extrusion. A uniform melt is formed through the shearing action of the screw. The molten material is transported to the tablet press for cooling and tableting, and then coarse crushing, grinding and fine crushing are carried out in sequence. Finally, the particle size is classified by grading and screening equipment to remove unqualified particles. After passing the test, the powder product is obtained. The whole process effectively solves the problem of insufficient traditional secondary mixing and stirring through the coordinated work of various components, and improves the quality and performance of the coating.

[0047] It should be understood that the above-described specific embodiments of the present invention are merely illustrative or illustrative of the principles of the present invention and do not constitute limitations of the present invention. Therefore, any modifications, equivalent substitutions, improvements, etc. made without departing from the spirit and scope of the present invention should be included within the scope of protection of the present invention. In addition, the appended claims are intended to cover all variations and modifications that fall within the scope and metes and bounds of the appended claims, or equivalents thereof.

Claims

1. An environmentally friendly solvent-free coating, characterized in that: The following raw materials are included, and the raw materials are expressed in percentage by mass: Polyester resin 40-70%, high gloss barium sulfate 3-8%, precipitated barium sulfate 5-10%, calcium carbonate 6-12%, hydroxyalkylamide 4-12%, pigments and fillers 15-20%, nano-silica 4-6%, hollow glass microspheres 4-6%, curing inhibitor 0.05-0.2%, lubricant 0.1-0.5%, leveling agent 0.8-3%, benzoin 0.8-1%, anti-UV absorber 0.8-2%; The pigments and fillers include zinc oxide and aluminum silicate fibers.

2. A method for preparing an environmentally friendly solvent-free coating, using the environmentally friendly solvent-free coating according to claim 1, characterized in that: The following steps are involved: Step 1: Drying: Dry all raw materials before mixing; Step 2: Mixing: The main raw materials, polyester resin, high-gloss barium sulfate, precipitated barium sulfate, calcium carbonate and hollow glass microspheres are put into a blender for pre-mixing. After the pre-mixing is completed, the remaining raw materials are added to the pre-mixed materials for secondary mixing; Step 3: Melt extrusion: The mixed materials are sent to the extruder for mixing, and the materials are melted and sheared by the shearing action of the screw of the extruder; Step 4: Cooling and tableting: The molten material extruded from the extruder is conveyed to the tablet press, and the molten material is squeezed into thin sheets by the roller pressing action of the tablet press, and then cooled to room temperature; Step 5: Coarsely crush the flaky material into smaller particles, and then grind them into fine particles; Step 6. Finished product: The crushed powder is passed through a grading and screening device for particle size classification to remove unqualified coarse particles and fine powder, and then the powder product is obtained after testing.

3. The method for preparing an environmentally friendly solvent-free coating according to claim 2, characterized in that: The mixer comprises a mixing drum (1), a spiral spreading assembly (2), a rotating tube (3), a V-shaped elastic stirring member (4), a driving member (5) and a hot air supply member (6), wherein the spiral spreading assembly (2) is mounted on the top of the mixing drum (1), the rotating tube (3) is vertically arranged in the mixing drum (1), a plurality of circumferentially arranged V-shaped elastic stirring members (4) are mounted on the rotating tube (3), an exhaust valve (102) matched with the V-shaped elastic stirring member (4) is mounted on the inner wall of the mixing drum (1), a hot air nozzle (31) is mounted on the rotating tube (3), and the hot air supply member (6) is used to guide hot air into the rotating tube (3) and discharge it through the hot air nozzle (31); The rotating tube (3) is driven by the driving member (5) to drive the spiral spreading assembly (2) and the V-shaped elastic stirring member (4) to rotate simultaneously. When the spiral spreading assembly (2) rotates, the material is thrown into the stirring drum (1) in a spiral shape. When the V-shaped elastic stirring member (4) rotates, it stirs the material and when it passes through the semi-arc protrusion (101) and collides with it, it deforms and squeezes the material.

4. The method for preparing an environmentally friendly solvent-free coating according to claim 3, characterized in that: The V-shaped elastic stirring member (4) includes a first stirring plate (41), a second stirring plate (42) and an arc-shaped elastic sheet (43). The first stirring plate (41) and the second stirring plate (42) are hinged to each other to form a V-shaped structure. The first stirring plate (41) is fixedly connected to the rotating tube (3). The semi-arc protrusion (101) corresponds to the rotation path of the second stirring plate (42). The arc-shaped elastic sheet (43) is connected between the first stirring plate (41) and the second stirring plate (42). The first stirring plate (41) and the second stirring plate (42) are both provided with sieve holes (44).

5. The method for preparing an environmentally friendly solvent-free coating according to claim 4, characterized in that: An extrusion structure (45) is installed on the inner side of each of the first stirring plate (41) and the second stirring plate (42); The extrusion structure (45) comprises a plurality of groups of extrusion rods (451), and the length and diameter of each group of extrusion rods (451) increase in sequence from the adjacent ends of the first stirring plate (41) and the second stirring plate (42) to the distal ends.

6. The method for preparing an environmentally friendly solvent-free coating according to claim 3, characterized in that: The spiral spreading assembly (2) includes a loading seat (21), a feeding barrel (22) and a spiral spreading member (23), wherein the loading seat (21) is mounted on the top of the mixing barrel (1), and a through assembly channel is provided in the loading seat (21), the rotating tube (3) rotates through the bottom of the feeding barrel (22) and is provided with a push plate (32) located in the feeding barrel (22), the top of the feeding barrel (22) is covered with an end cover (222), the spiral spreading member (23) is fixedly mounted on the rotating tube (3) and is located in the assembly channel, and the bottom of the feeding barrel (22) is provided with an eccentrically arranged drop port (221) connected to the spiral spreading member (23).

7. The method for preparing an environmentally friendly solvent-free coating according to claim 6, characterized in that: The spiral spreading member (23) comprises a spreading barrel (231), which is fixedly sleeved on the rotating tube (3) and located in the assembly channel. The drop opening (221) is communicated with the spreading barrel (231), and the bottom of the spreading barrel (231) is symmetrically connected to two spreading pipes (232) located in the mixing barrel (1), and the spreading pipes (232) are inclined outward from the bottom of the spreading barrel (231).

8. The method for preparing an environmentally friendly solvent-free coating according to claim 3, characterized in that: The hot air supply component (6) comprises a rotary joint (61), a hot air pipe (62) and a hot air blower (63). The rotary joint (61) is installed at the bottom of the mixing drum (1). The bottom end of the rotary pipe (3) rotates through the bottom of the mixing drum (1) and is connected to the rotating air outlet end of the rotary joint (61). The air inlet end of the rotary joint (61) is connected to the hot air blower (63) through the hot air pipe (62).

9. The method for preparing an environmentally friendly solvent-free coating according to claim 8, characterized in that: The driving member (5) comprises a driven gear (51), a driving gear (52) and a motor (53); the driven gear (51) is fixedly sleeved on the bottom end of the rotating tube (3) and is located between the mixing drum (1) and the rotary joint (61); the motor (53) is installed at the bottom of the mixing drum (1); and the output end of the motor (53) is connected to the driving gear (52) meshing with the driven gear (51).

10. The method for preparing an environmentally friendly solvent-free coating according to claim 3, characterized in that: An exhaust valve (102) is connected to the outer periphery of the mixing drum (1), a discharge pipe (103) is connected to the bottom of the mixing drum (1), and a control valve (104) is installed on the discharge pipe (103).

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