Continuous preparation method of formaldehyde-free flame-retardant adhesive

Abstract

The invention discloses a continuous preparation method of a formaldehyde-free flame-retardant adhesive, which comprises the following steps: respectively preparing a main adhesive flow A and a cross-linked flame-retardant flow B, continuously pumping the main adhesive flow A and the cross-linked flame-retardant flow B into a static mixer according to a fixed ratio, reacting in a sectional temperature control tubular reactor, and quickly cooling to obtain a finished product, according to the method, stable, efficient and continuous production of the formaldehyde-free environment-friendly adhesive is achieved, in order to implement the method, integrated preparation equipment is further provided and comprises two sets of proportioning and mixing mechanisms, each set of proportioning and mixing mechanism is matched with a ratchet wheel assembly through a first driving device, stirring and material pumping in a reaction kettle are synchronously achieved, and the purpose of continuous production of the formaldehyde-free environment-friendly adhesive is achieved. Materials are pumped into the two sets of independent heat preservation storage tanks and then synchronously conveyed by the pumping assembly in proportion, the stored main glue flow A and the cross-linked flame retardant flow B are stirred through the stirring assembly, and the equipment achieves multi-process collaborative operation with the least power source, is compact in structure and reliable in operation, and guarantees accuracy and stability of continuous production.

Description

Technical Field

[0001] This invention relates to the technical field of adhesive preparation methods, specifically a continuous preparation method for formaldehyde-free flame-retardant adhesives. Background Technology

[0002] With the increasing awareness of environmental protection and safety, the fields of artificial board, decorative materials and furniture manufacturing have put forward higher requirements for adhesives. Traditional aldehyde resin adhesives (such as urea-formaldehyde resin and phenolic resin) are widely used because of their low raw material cost and mature technology. However, they will continue to release harmful volatile organic compounds such as formaldehyde during production and use, which seriously endanger human health and environmental safety. Therefore, the development of high-performance and formaldehyde-free environmentally friendly adhesives has become an important development direction for the industry.

[0003] At the same time, the construction, transportation and other fields have mandatory or high standards for the flame retardant performance of materials. At present, the common practice is to apply flame retardants by impregnation or coating after the substrate such as artificial board is formed. This method has problems such as easy peeling of flame retardant layer, poor durability, affecting the mechanical properties of substrate, and complicated process. Integrating flame retardant function into adhesive body in chemical or physical way to prepare adhesive with intrinsic flame retardant properties is an ideal way to achieve efficient flame retardancy and structural integration of materials.

[0004] Furthermore, existing formaldehyde-free or flame-retardant adhesives are mostly produced using batch reactor processes. This process typically involves sequentially completing all steps, such as adding raw materials, heating the reaction, and adjusting the temperature, within a single reactor. This process has inherent drawbacks, including low production efficiency, large batch-to-batch quality fluctuations, high energy consumption, and difficulty in precisely controlling the reaction process (such as instantaneous heating and cooling). In particular, for systems that require precise and uniform mixing and reaction of the main adhesive with a solid flame retardant suspension, batch processes are more prone to problems such as uneven mixing, violent local reactions, and solid particle sedimentation, which affect the stability and performance of the final product. Summary of the Invention

[0005] In view of the above-mentioned shortcomings in the existing technology, the purpose of this invention is to provide an environmentally friendly, efficient, continuously producible, and low-failure-rate method for preparing formaldehyde-free flame-retardant adhesives.

[0006] The technical solution adopted by the present invention to achieve the above objectives is: a continuous preparation method for a formaldehyde-free flame-retardant adhesive, comprising the following steps:

[0007] S1. Preparation of main adhesive A flow:

[0008] S2. Preparation of cross-linked flame-retardant B-flow;

[0009] S3. Store the prepared main adhesive A stream in a warm place, and store the prepared crosslinked flame retardant B stream in a warm place.

[0010] S4. Pump the thermal insulation main adhesive A stream and the cross-linked flame retardant B stream into the static mixer in proportion;

[0011] S5. The mixture after being mixed in the static mixer is conveyed to the segmented temperature-controlled tubular reactor;

[0012] S6. The material output from the segmented temperature-controlled tubular reactor is sent to a heat exchanger for cooling.

[0013] S7. The cooled material flows into the finished product buffer tank.

[0014] In the above technical solution, the preparation steps of the main adhesive A flow include:

[0015] S1-1, The proportions by weight are as follows:

[0016] 70 parts deionized water, 15 parts polyvinyl alcohol, 5 parts acrylic acid, 0.3 parts ammonium persulfate;

[0017] S1-2. Add 70 parts of deionized water to the A flow dissolving tank, start stirring and heat to 85°C;

[0018] S1-3. Slowly add 15 parts of polyvinyl alcohol;

[0019] S1-4. Heat to 95℃, keep warm and stir for 1.5 hours until the polyvinyl alcohol is completely dissolved and the solution is clear and transparent;

[0020] S1-5, Cool down to 65℃;

[0021] S1-6, 5 parts of acrylic acid are slowly added dropwise to the A flow dissolving tank, and the reaction temperature is controlled to be less than 70°C;

[0022] S1-7, 0.3 parts ammonium persulfate, which is pre-dissolved in 5 parts water and added to the A flow dissolving tank;

[0023] S1-8. Keep the reaction at 65±2℃ for 40 minutes to obtain the main adhesive A flow.

[0024] In the above technical solution, the preparation steps of the crosslinked flame retardant B-flow include:

[0025] S2-1. The proportions by weight are as follows:

[0026] 75 parts deionized water, 15 parts ammonium polyphosphate, 5 parts melamine, 5 parts pentaerythritol;

[0027] S2-2. Add 75 parts of deionized water to the B flow preparation tank and start stirring.

[0028] S2-3, add 15 parts ammonium polyphosphate, 5 parts melamine, and 5 parts pentaerythritol in sequence;

[0029] S2-4. After the solid is completely dispersed, slowly add 5% sodium hydroxide solution to adjust the pH of the system to 8.5, and obtain cross-linked flame retardant B flow.

[0030] In the above technical solution, in step S3, the insulation temperature of the insulated storage tank A is 60±2℃, and the insulation temperature of the insulated storage tank B is 40±2℃.

[0031] In addition, in step S4, the mass ratio of the main adhesive A stream to the crosslinked flame retardant B stream is 7:1.

[0032] Furthermore, in step S5, the segmented temperature-controlled tubular reactor includes a first reaction section and a second reaction section, wherein the reaction temperature of the first reaction section is 70±2℃ and the temperature of the second reaction section is 83±2℃.

[0033] Furthermore, in step S6, a plate heat exchanger is used, through which the material is cooled by cooling water from 83±2℃ to below 35℃ within 15 seconds.

[0034] In one embodiment, steps S1-S4 are performed in an integrated preparation device;

[0035] The integrated preparation equipment includes a base frame, a mixing mechanism, and a heat-insulating conveying mechanism. Two sets of the mixing mechanism are fixedly connected to the base frame. One set of the mixing mechanism is used for the preparation of the main adhesive A stream, and the other set of the mixing mechanism is used for the preparation of the crosslinked flame retardant B stream.

[0036] The heat-insulating conveying mechanism is fixedly connected to the equipment base frame. The heat-insulating conveying mechanism includes a heat-insulating storage tank, a stirring assembly, and a pumping assembly. There are two sets of heat-insulating storage tanks. One set of heat-insulating storage tanks is connected to one set of proportioning and mixing mechanisms through pipelines for heat-insulating and storing the main adhesive A stream. The other set of heat-insulating storage tanks is connected to another set of proportioning and mixing mechanisms through pipelines for heat-insulating and storing the cross-linked flame retardant B stream.

[0037] The pumping assembly is connected to the pipelines of the two sets of insulated storage tanks, and the main adhesive A stream and the crosslinked flame retardant B stream are pumped to the static mixer in proportion through the pumping assembly;

[0038] The two sets of insulated storage tanks cooperate with the stirring assembly, which can stir the main adhesive A stream and the cross-linked flame retardant B stream.

[0039] In the aforementioned integrated preparation equipment, the proportioning and mixing mechanism adopts the following structure:

[0040] The proportioning and mixing mechanism includes a reaction vessel, a proportioning stirring paddle, a non-powered pump, a ratchet assembly, and a first driving device. The reaction vessel is fixedly connected to the equipment base frame, the proportioning stirring paddle is rotatably connected to the reaction vessel, a first worm gear is fixedly connected to the proportioning stirring paddle, and a first worm is rotatably connected to the reaction vessel. The first worm is meshed with the first worm gear.

[0041] The non-powered pump is fixedly connected to the equipment base frame. The inlet of the non-powered pump is connected to the outlet pipeline of the reaction vessel, and the outlet of the non-powered pump is connected to the inlet pipeline of a set of insulated storage tanks.

[0042] A central rotating shaft is rotatably connected to the equipment base frame. The ratchet assembly is mounted on the central rotating shaft. The first driving device is fixedly connected to the equipment base frame. The first driving device is poweredly connected to the central rotating shaft. The central rotating shaft is poweredly connected to the first worm gear through a first transmission assembly located at the power input end of the ratchet assembly. The central rotating shaft is poweredly connected to the pump shaft of the unpowered pump through a second transmission assembly located at the power output end of the ratchet assembly.

[0043] In the aforementioned integrated preparation equipment, the pumping assembly adopts the following structure:

[0044] The pumping assembly includes a second drive unit and a piston pump, wherein the piston pump is provided in two sets;

[0045] The piston pump includes a piston cylinder, a piston body, a piston rod, an inlet pipe, an outlet pipe, a first check valve, and a second check valve. The piston cylinder is fixedly connected to the equipment base frame. The piston cylinder has a piston chamber inside. The piston body is located inside the piston cylinder. The piston rod is fixedly connected to the piston body. The inlet pipe and the outlet pipe are fixedly connected to the bottom of the piston cylinder. The first check valve is fixedly connected to the inlet pipe, and the second check valve is fixedly connected to the outlet pipe.

[0046] In the two sets of piston pumps, the capacity of the piston chamber is set differently according to the required ratio, and the size of the matching piston body is different;

[0047] According to the required proportion, the inlet pipe of one set of piston pumps is connected to the outlet pipe of the corresponding insulated storage tank, and the inlet pipe of the other set of piston pumps is connected to the outlet pipe of the corresponding insulated storage tank.

[0048] The outlet pipes of both sets of piston pumps are connected to the inlet pipe of the static mixer;

[0049] The second drive device is poweredly connected to both sets of piston rods;

[0050] Furthermore, the top ends of both sets of piston rods are fixedly connected to traction frames, and a sliding frame is fixedly connected to the equipment base frame. The traction frame is slidably connected to the sliding frame, and the second drive device cooperates with the traction frame so that the second drive device can pull the traction frame to perform reciprocating linear motion on the sliding frame.

[0051] In the aforementioned integrated preparation equipment, the stirring assembly adopts the following structure:

[0052] The stirring assembly includes a storage stirring paddle, a second worm gear, and a second worm wheel. Each set of insulated storage tanks is rotatably connected to the storage stirring paddle, each set of storage stirring paddles is fixedly connected to the second worm wheel, each set of insulated storage tanks is rotatably connected to the second worm gear, the second worm gear meshes with the corresponding second worm wheel, and the second drive device is poweredly connected to the two sets of second worm gears.

[0053] Furthermore, the two sets of second worm gears are fixedly connected by a connecting shaft, on which a gear is fixedly connected, and on which a rack is fixedly connected, and which meshes with the gear.

[0054] The beneficial effects of this invention are:

[0055] 1. The adhesive does not contain formaldehyde or other harmful substances, thus solving the formaldehyde release problem of traditional wood-based panel adhesives from the source. The product is green and environmentally friendly. Furthermore, by pre-formulating the three intumescent flame retardant components, ammonium polyphosphate, melamine, and pentaerythritol, into a B-flow, and combining them with the main adhesive A-flow during the reaction, the flame retardant function is integrated into the adhesive body rather than simply being added physically, resulting in more stable performance. In addition, the continuous production process replaces the traditional batch reactor reaction, which has significant advantages such as high production efficiency, good batch stability, uniform product quality, and easy automation control.

[0056] 2. The preparation, storage, metering, conveying, and mixing of the main adhesive A stream and the crosslinked flame retardant B stream are integrated into an integrated preparation equipment. It has a compact structure, small footprint, and is easy to install and manage.

[0057] 3. The proportioning and mixing mechanism of the integrated preparation equipment, through a first drive device, a central shaft, and a ratchet assembly, can drive the proportioning stirring paddle and the non-powered pump. When the main adhesive A stream or the cross-linked flame retardant B stream is prepared through the proportioning and mixing mechanism, the first drive device can rotate forward to drive the proportioning stirring paddle, thereby stirring the raw materials during proportioning. Due to the unidirectional transmission characteristic of the ratchet assembly, the non-powered pump does not work. When the main adhesive A stream or the cross-linked flame retardant B stream is prepared and needs to be transported to the insulated storage tank for storage, the first drive device rotates in reverse to activate the non-powered pump. At this time, the non-powered pump can pump the main adhesive A stream or the cross-linked flame retardant B stream into the corresponding insulated storage tank. In this way, a single drive device can realize the stirring and pumping work, reducing the complexity of equipment control and reducing the failure rate.

[0058] 4. The pumping component of the integrated preparation equipment uses two sets of piston pumps with fixed piston chamber volumes in a fixed ratio. They are driven synchronously by a second drive device. With this structure, the volume difference of the piston chambers directly determines the transport volume ratio of the main adhesive A flow and the cross-linked flame retardant B flow. It is not affected by factors such as flow meter accuracy and fluid viscosity changes. The ratio accuracy is extremely high and absolutely synchronized. At the same time, the second drive device synchronously controls the two piston pumps, ensuring that the start-up, stop and speed of the main adhesive A flow and the cross-linked flame retardant B flow are completely consistent, fundamentally eliminating the imbalance of the ratio.

[0059] 5. The stirring component of the integrated preparation equipment is also powered by a second drive device. When the second drive device drives the traction frame to reciprocate linearly, the rack drives the gear to rotate, and then the power of the gear is transmitted to the two sets of storage stirring paddles. This ensures that the material in the insulated storage tank is uniform, prevents sedimentation or stratification, and eliminates the need for a separate motor for stirring, making it energy-saving and reliable. Attached Figure Description

[0060] Figure 1 This is a front view structural diagram of the present invention;

[0061] Figure 2 This is a three-dimensional structural diagram of the present invention;

[0062] Figure 3 This is a structural schematic diagram of the present invention from another angle;

[0063] Figure 4 This is a schematic diagram of the mixing mechanism in this invention;

[0064] Figure 5 This is a schematic diagram of the mixing mechanism in this invention from another angle;

[0065] Figure 6 This is a schematic diagram of the thermal insulation conveying mechanism in this invention;

[0066] Figure 7 This is a schematic diagram of the heat preservation and conveying mechanism of the present invention from another angle;

[0067] Figure 8 This is a schematic diagram of the piston pump in this invention;

[0068] Figure 9 This is a schematic diagram of the pipeline connection structure in this invention;

[0069] Figure 10 This is a schematic diagram of the pipeline connection from another angle in this invention.

[0070] In the diagram: 100 equipment base frame;

[0071] 200 Proportioning mixing mechanism, 201 Reactor, 202 Proportioning stirring paddle, 203 Non-powered pump, 204 Ratchet assembly, 205 First drive device, 206 First worm gear, 207 First worm, 208 Central rotating shaft, 209 First transmission assembly, 210 Second transmission assembly;

[0072] 300 Insulated Conveyor Mechanism;

[0073] 301 Insulated Storage Tank;

[0074] 302 stirring assembly, 3021 storage stirring paddle, 3022 second worm gear, 3023 second worm wheel, 3024 connecting shaft, 3025 gear, 3026 rack;

[0075] 303 Pumping assembly, 3031 Second drive device, 3032 Piston pump, 30321 Piston cylinder, 30322 Piston body, 30323 Piston rod, 30324 Inlet pipe, 30325 Outlet pipe, 30326 First check valve, 30327 Second check valve, 30328 Piston chamber, 3033 Traction frame, 3034 Sliding frame;

[0076] 400 static mixer. Detailed Implementation

[0077] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention.

[0078] Example 1

[0079] A continuous preparation method for a formaldehyde-free flame-retardant adhesive includes the following steps:

[0080] S1. Preparation of main adhesive A flow:

[0081] First, prepare the raw materials according to the predetermined mass proportions. The specific formula is: 70 parts deionized water, 15 parts polyvinyl alcohol, 5 parts acrylic acid, and 0.3 parts ammonium persulfate.

[0082] During operation, first add the measured amount of deionized water to the reaction vessel, start stirring and heating to raise the water temperature to 85°C. Then, while stirring continuously, slowly and evenly add 15 parts of polyvinyl alcohol to the water.

[0083] After the addition of materials is complete, the system is heated to 95°C and stirred at this temperature for 1.5 hours until the polyvinyl alcohol is completely dissolved and the resulting solution is clear and transparent.

[0084] Next, the solution temperature is lowered to 65°C. At this temperature, 5 parts of acrylic acid are slowly added to the reaction vessel dropwise. During this process, the reaction temperature must be strictly controlled not to exceed 70°C.

[0085] Next, 0.3 parts of ammonium persulfate were dissolved in 5 parts of deionized water, and then the solution was added to the reaction system.

[0086] Finally, the reaction system was maintained at 65±2℃ and the reaction was continued for 40 minutes. After the reaction was completed, the resulting uniform adhesive solution was the main adhesive A flow.

[0087] S2. Preparation of cross-linked flame-retardant B-flow:

[0088] First, prepare the raw materials according to the following mass proportions: 75 parts deionized water, 15 parts ammonium polyphosphate, 5 parts melamine, and 5 parts pentaerythritol.

[0089] During operation, first add the measured amount of deionized water to the preparation container and start stirring;

[0090] Then, add 15 parts of ammonium polyphosphate, 5 parts of melamine and 5 parts of pentaerythritol to water in sequence, and stir continuously until all solid powders are completely dispersed in water to form a uniform suspension.

[0091] Finally, a 5% sodium hydroxide solution was slowly added dropwise to the suspension while stirring, and the pH of the entire system was adjusted to 8.5 to obtain the cross-linked flame retardant B flow.

[0092] S3. Insulated storage of materials:

[0093] The prepared main adhesive A stream is transported to a dedicated insulated storage tank for storage. The insulated storage tank is equipped with a temperature control device that can keep the temperature of the material inside the tank constant within the range of 60±2℃.

[0094] Similarly, the prepared cross-linked flame retardant B stream was transported to another dedicated insulated storage tank for storage, and its storage temperature was kept constant within the range of 40±2℃.

[0095] Both insulated storage tanks are equipped with gentle stirring devices to prevent the solid particles in stream B from settling during storage and to maintain the uniformity of stream A.

[0096] S4. Precise mixing and conveying of materials:

[0097] The main adhesive A stream and the cross-linked flame retardant B stream, stored in their respective insulated storage tanks, are pumped out through independent conveying pipelines at a fixed mass conveying ratio. Specifically, the conveying mass ratio is 7 parts of the main adhesive A stream to 1 part of the cross-linked flame retardant B stream. These two material streams are pumped synchronously and proportionally into the inlet of a static mixer. The static mixer is equipped with special mixing elements that enable the two material streams to be mixed quickly, efficiently, and uniformly as they flow through, forming a preliminary mixed material.

[0098] S5, segmented temperature-controlled reaction:

[0099] The mixture flowing out of the static mixer is immediately introduced into a segmented temperature-controlled tubular reactor for reaction. The tubular reactor is divided into two reaction sections with independent temperature control along the material flow direction. The mixture first enters the first reaction section, where the reaction temperature is precisely controlled at 70±2℃. Subsequently, the material flows into the second reaction section, where the reaction temperature is precisely controlled at 83±2℃. This step-by-step heating method provides an optimized reaction temperature process for the components in the material, ensuring the fullness and controllability of the crosslinking and polymerization reactions.

[0100] S6. Rapid cooling of the reaction products:

[0101] The reacting binder material flows out from the end of the segmented temperature-controlled tubular reactor and then enters a heat exchanger, preferably a plate heat exchanger. Inside the heat exchanger, the high-temperature material at around 83°C undergoes efficient countercurrent heat exchange with cooling water. By design, the material is rapidly cooled in a very short time (e.g., 15 seconds), with the temperature dropping sharply from 83±2°C to below 35°C. This rapid cooling process can effectively terminate the reaction, "lock in" the product's performance, and prevent its performance from changing due to continuous heating.

[0102] S7. Finished Product Collection:

[0103] After being rapidly cooled, the finished adhesive product is temporarily stored in a finished product buffer tank for subsequent packaging or direct application.

[0104] Example 2

[0105] Please see Figures 1-10 A continuous preparation method for a formaldehyde-free flame-retardant adhesive is described in this embodiment, which provides an integrated preparation device based on Example 1. This integrated preparation device is used for the production of S1-S4 in Example 1. For details, please refer to... Figures 1-3 The integrated preparation equipment includes an equipment base frame 100, a proportioning and mixing mechanism 200, and a heat-insulating conveying mechanism 300. Two sets of proportioning and mixing mechanisms 200 are fixedly connected to the equipment base frame 100. One set of proportioning and mixing mechanisms 200 is used for the preparation of the main adhesive A stream, and the other set of proportioning and mixing mechanisms 200 is used for the preparation of the crosslinked flame retardant B stream.

[0106] A heat-insulating conveying mechanism 300 is also fixedly connected to the equipment base frame 100. The heat-insulating conveying mechanism 300 includes a heat-insulating storage tank 301, a stirring assembly 302, and a pumping assembly 303. There are two sets of heat-insulating storage tanks 301. One set of heat-insulating storage tanks 301 is connected to a set of proportioning and mixing mechanisms 200 through pipelines for heat-insulating and storing the main adhesive A stream. The other set of heat-insulating storage tanks 301 is connected to another set of proportioning and mixing mechanisms 200 through pipelines for heat-insulating and storing the cross-linked flame retardant B stream.

[0107] Furthermore, the pumping assembly 303 is connected to the pipelines of two sets of insulated storage tanks 301, and the main adhesive A stream and the crosslinked flame retardant B stream are pumped to the static mixer 400 in proportion through the pumping assembly 303.

[0108] In addition, the two sets of insulated storage tanks 301 are used in conjunction with the stirring assembly 302, which can stir the main adhesive A stream and the cross-linked flame retardant B stream.

[0109] To elaborate further, please refer to Figure 4 , Figure 5 , Figure 9 , Figure 10 The proportioning and mixing mechanism 200 includes a reaction vessel 201, a proportioning stirring paddle 202, a non-powered pump 203, a ratchet assembly 204, and a first driving device 205. Specifically, the reaction vessel 201 is fixedly connected to the equipment base frame 100, the proportioning stirring paddle 202 is rotatably connected to the reaction vessel 201, the first worm gear 206 is fixedly connected to the proportioning stirring paddle 202, and the first worm 207 is rotatably connected to the reaction vessel 201. The first worm 207 is meshed with the first worm gear 206.

[0110] In addition, a non-powered pump 203 is fixedly connected to the equipment base frame 100. The inlet of the non-powered pump 203 is connected to the outlet pipeline of the reactor 201. The outlet of the reactor 201 is equipped with a material valve. The outlet of the non-powered pump 203 is connected to the inlet pipeline of a set of insulated storage tanks 301.

[0111] A central rotating shaft 208 is rotatably connected to the equipment base frame 100. A ratchet assembly 204 is provided on the central rotating shaft 208. A first driving device 205 is fixedly connected to the equipment base frame 100. The first driving device 205 is poweredly connected to the central rotating shaft 208. The central rotating shaft 208 is poweredly connected to the first worm gear 207 through a first transmission assembly 209. The first transmission assembly 209 is located on the power input end side of the ratchet assembly 204. The central rotating shaft 208 is poweredly connected to the pump shaft of the unpowered pump 203 through a second transmission assembly 210. The second transmission assembly 210 is located on the power output end side of the ratchet assembly 204.

[0112] The first transmission component 209 and the second transmission component 210 can both be a combination of sprockets and chains or a combination of belts and pulleys, while the first drive device 205 can be a motor.

[0113] When the main adhesive A stream or cross-linked flame retardant B stream is prepared by the above-mentioned mixing mechanism 200, it can be carried out according to step S1 or S2. When it is necessary to stir the raw materials, the first drive device 205 can rotate forward to drive the central shaft 208 to rotate. Then, under the action of the first transmission component 209, the first worm gear 207 is driven to rotate. The first worm gear 207 then drives the first worm wheel 206 to rotate, and finally realizes the rotation of the mixing paddle 202. At this time, under the action of the ratchet component 204, the unpowered pump 203 does not rotate.

[0114] After preparation is completed, the first drive device 205 reverses to drive the central shaft 208 to rotate. At this time, under the action of the ratchet assembly 204, the power can be transmitted to the unpowered pump 203 through the second transmission assembly 210. Then the material valve of the reactor 201 is opened, so that the material in the reactor 201 can be extracted by the pump.

[0115] With the above structural design, not only can the needs of stirring and pumping be met as needed, but the number of drive devices is also reduced, thereby reducing the failure rate.

[0116] To go further, please refer to Figures 6-10 The pumping assembly 303 includes a second drive unit 3031 and a piston pump 3032, with two sets of piston pumps 3032.

[0117] Taking a set of piston pumps 3032 as an example, the piston pump 3032 includes a piston cylinder 30321, a piston body 30322, a piston rod 30323, an inlet pipe 30324, an outlet pipe 30325, a first check valve 30326, and a second check valve 30327. The piston cylinder 30321 is fixedly connected to the equipment base frame 100. The piston cylinder 30321 is provided with a piston chamber 30328. The piston body 30322 is provided inside the piston cylinder 30321. The piston rod 30323 is fixedly connected to the piston body 30322. The inlet pipe 30324 and the outlet pipe 30325 are fixedly connected to the bottom of the piston cylinder 30321. The first check valve 30326, which only allows fluid to enter the piston chamber 30328, is fixedly connected to the inlet pipe 30324. The second check valve 30327, which only allows fluid to exit the piston chamber 30328, is fixedly connected to the outlet pipe 30325.

[0118] In order to meet the delivery ratio requirements, such as the required 7:1, the piston chamber 30328 of the two sets of piston pumps 3032 are designed with different sizes, and the piston bodies 30322 are also different in size. According to the required ratio, the inlet pipe 30324 of the larger capacity piston pump 3032 is connected to the outlet of the insulated storage tank storing the main adhesive A flow through a pipeline, and the inlet pipe 30324 of the smaller capacity piston pump 3032 is connected to the outlet of the insulated storage tank storing the cross-linked flame retardant B flow through a pipeline. The outlet pipes 30325 of both sets of piston pumps 3032 are connected to the inlet pipeline of the static mixer 400.

[0119] The second drive unit 3031 is poweredly connected to both sets of piston rods 30323. Furthermore, a traction frame 3033 is fixedly connected to the top of each set of piston rods 30323. A sliding frame 3034 is fixedly connected to the equipment base frame 100, and the traction frame 3033 is slidably connected to the sliding frame 3034. The second drive unit 3031 cooperates with the traction frame 3033, enabling the second drive unit 3031 to pull the traction frame 3033 to reciprocate linearly on the sliding frame 3034. When the traction frame 3033 reciprocates, it synchronously drives the two sets of piston rods 30323 and their piston bodies 3032. 2. Reciprocating motion. Since the volume of piston chamber 30328 is fixed, materials are synchronously and quantitatively extracted and pumped from the two insulated storage tanks in a fixed volume ratio (corresponding to the required mass ratio). This pumping structure is not affected by factors such as flow meter accuracy and fluid viscosity changes. The proportioning accuracy is extremely high and absolutely synchronous. At the same time, a second drive device 3031 synchronously controls two piston pumps 3032, ensuring that the start-up, stop and speed of the main adhesive A flow and the cross-linked flame retardant B flow are completely consistent, fundamentally eliminating the proportion imbalance. In addition, the second drive device 3031 here can be a servo electric telescopic cylinder.

[0120] Furthermore, the stirring assembly 302 includes a storage stirring paddle 3021, a second worm gear 3022, and a second worm wheel 3023. Specifically, a storage stirring paddle 3021 is rotatably connected to each set of insulated storage tanks 301, a second worm wheel 3023 is fixedly connected to each set of storage stirring paddles 3021, and a second worm gear 3022 is rotatably connected to each set of insulated storage tanks 301. The second worm gear 3022 meshes with the corresponding second worm wheel 3023. The second drive device 3031 is poweredly connected to the two sets of second worm gears 3022. More specifically, the two sets of second worm gears 3022 are fixedly connected via a connecting shaft 3024, on which a gear 3025 is fixedly connected. A traction frame 3033 is fixedly... A rack 3026 is connected, and the rack 3026 meshes with a gear 3025. When the second drive device 3031 drives the traction frame 3033 to perform reciprocating linear motion, the rack 3026 on the traction frame 3033 moves accordingly, driving the gear 3025 meshing with it to rotate alternately in the forward and reverse directions. The rotation of the gear 3025 is transmitted to the two second worm gears 3022 through the connecting shaft 3024. The second worm gears 3022 drive the second worm wheel 3023 meshing with it and the storage stirring paddle 3021 to rotate, thereby realizing the synchronous stirring of the stirring paddles in the two insulated storage tanks. By stirring the material in the insulated storage tank 301, sedimentation or stratification can be prevented, and there is no need to configure a separate motor for stirring, which is energy-saving and reliable.

[0121] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the present invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

[0122] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A continuous preparation method for a formaldehyde-free flame-retardant adhesive, characterized in that, Includes the following steps: S1. Preparation of main adhesive A flow: S2. Preparation of cross-linked flame-retardant B-flow; S3. Store the prepared main adhesive A stream in a warm place, and store the prepared crosslinked flame retardant B stream in a warm place. S4. Pump the thermal insulation main adhesive A stream and the cross-linked flame retardant B stream into the static mixer in proportion; S5. The mixture after being mixed in the static mixer is conveyed to the segmented temperature-controlled tubular reactor; S6. The material output from the segmented temperature-controlled tubular reactor is sent to a heat exchanger for cooling. S7. The cooled material flows into the finished product buffer tank.

2. The continuous preparation method of a formaldehyde-free flame-retardant adhesive according to claim 1, characterized in that, The preparation steps of the main adhesive A stream include: S1-1, The proportions by weight are as follows: 70 parts deionized water, 15 parts polyvinyl alcohol, 5 parts acrylic acid, 0.3 parts ammonium persulfate; S1-2. Add 70 parts of deionized water to the A flow dissolving tank, start stirring and heat to 85°C; S1-3. Slowly add 15 parts of polyvinyl alcohol; S1-4. Heat to 95℃, keep warm and stir for 1.5 hours until the polyvinyl alcohol is completely dissolved and the solution is clear and transparent; S1-5, Cool down to 65℃; S1-6, 5 parts of acrylic acid are slowly added dropwise to the A flow dissolving tank, and the reaction temperature is controlled to be less than 70°C; S1-7, 0.3 parts ammonium persulfate, which is pre-dissolved in 5 parts water and added to the A flow dissolving tank; S1-8. Keep the reaction at 65±2℃ for 40 minutes to obtain the main adhesive A flow.

3. The continuous preparation method of a formaldehyde-free flame-retardant adhesive according to claim 2, characterized in that, The preparation steps of the crosslinked flame retardant B-flow include: S2-1. The proportions by weight are as follows: 75 parts deionized water, 15 parts ammonium polyphosphate, 5 parts melamine, 5 parts pentaerythritol; S2-2. Add 75 parts of deionized water to the B flow preparation tank and start stirring. S2-3, add 15 parts ammonium polyphosphate, 5 parts melamine, and 5 parts pentaerythritol in sequence; S2-4. After the solid is completely dispersed, slowly add 5% sodium hydroxide solution to adjust the pH of the system to 8.5, and obtain cross-linked flame retardant B flow.

4. The continuous preparation method of a formaldehyde-free flame-retardant adhesive according to claim 3, characterized in that, In step S3, the insulation temperature of the insulated storage tank A is 60±2℃, and the insulation temperature of the insulated storage tank B is 40±2℃. In step S4, the mass ratio of the main adhesive A stream to the crosslinked flame retardant B stream is 7:

1. In step S5, the segmented temperature-controlled tubular reactor includes a first reaction section and a second reaction section. The reaction temperature of the first reaction section is 70±2℃, and the temperature of the second reaction section is 83±2℃. In step S6, a plate heat exchanger is used, through which the material is cooled by cooling water from 83±2℃ to below 35℃ within 15 seconds.

5. The continuous preparation method of a formaldehyde-free flame-retardant adhesive according to claim 4, characterized in that, Steps S1-S4 are performed in an integrated preparation device; The integrated preparation equipment includes a base frame (100), a mixing mechanism (200), and a heat-insulating conveying mechanism (300). Two sets of the mixing mechanisms (200) are fixedly connected to the base frame (100). One set of the mixing mechanisms (200) is used for the preparation of the main adhesive A stream, and the other set of the mixing mechanisms (200) is used for the preparation of the crosslinked flame retardant B stream. The heat-insulating conveying mechanism (300) is fixedly connected to the equipment base frame (100). The heat-insulating conveying mechanism (300) includes a heat-insulating storage tank (301), a stirring assembly (302), and a pumping assembly (303). There are two sets of heat-insulating storage tanks (301). One set of heat-insulating storage tanks (301) is connected to one set of proportioning and mixing mechanisms (200) through pipelines for heat-insulating and storing the main adhesive A stream. The other set of heat-insulating storage tanks (301) is connected to another set of proportioning and mixing mechanisms (200) through pipelines for heat-insulating and storing the cross-linked flame retardant B stream. The pumping assembly (303) is connected to the pipelines of the two sets of the insulated storage tanks (301), and the main adhesive A stream and the cross-linked flame retardant B stream are pumped to the static mixer (400) in proportion through the pumping assembly (303). The two sets of insulated storage tanks (301) cooperate with the stirring assembly (302), and the stirring assembly (302) can stir the main adhesive A stream and the crosslinked flame retardant B stream.

6. The continuous preparation method of a formaldehyde-free flame-retardant adhesive according to claim 5, characterized in that, The mixing mechanism (200) includes a reaction vessel (201), a mixing impeller (202), a non-powered pump (203), a ratchet assembly (204), and a first drive device (205). The reaction vessel (201) is fixedly connected to the equipment base frame (100). The mixing impeller (202) is rotatably connected to the reaction vessel (201). A first worm gear (206) is fixedly connected to the mixing impeller (202). A first worm (207) is rotatably connected to the reaction vessel (201). The first worm (207) meshes with the first worm gear (206). The equipment base frame (100) is fixedly connected to the non-powered pump (203), the inlet of the non-powered pump (203) is connected to the outlet pipeline of the reactor (201), and the outlet of the non-powered pump (203) is connected to the inlet pipeline of a set of insulated storage tanks (301). A central shaft (208) is rotatably connected to the equipment base frame (100). The ratchet assembly (204) is provided on the central shaft (208). The first drive device (205) is fixedly connected to the equipment base frame (100). The first drive device (205) is poweredly connected to the central shaft (208). The central shaft (208) is poweredly connected to the first worm gear (207) through a first transmission assembly (209). The first transmission assembly (209) is located on the power input end side of the ratchet assembly (204). The central shaft (208) is poweredly connected to the pump shaft of the unpowered pump (203) through a second transmission assembly (210). The second transmission assembly (210) is located on the power output end side of the ratchet assembly (204).

7. The continuous preparation method of a formaldehyde-free flame-retardant adhesive according to claim 6, characterized in that, The pumping assembly (303) includes a second drive unit (3031) and a piston pump (3032), wherein the piston pump (3032) is provided in two sets; The piston pump (3032) includes a piston cylinder (30321), a piston body (30322), a piston rod (30323), an inlet pipe (30324), an outlet pipe (30325), a first check valve (30326), and a second check valve (30327). The piston cylinder (30321) is fixedly connected to the equipment base frame (100). The piston cylinder (30321) has a piston chamber (30328) inside. 321) The piston body (30322) is provided inside, and the piston rod (30323) is fixedly connected to the piston body (30322). The bottom of the piston cylinder (30321) is fixedly connected to the inlet pipe (30324) and the outlet pipe (30325). The first one-way valve (30326) is fixedly connected to the inlet pipe (30324), and the second one-way valve (30327) is fixedly connected to the outlet pipe (30325). In the two sets of piston pumps (3032), the capacity of the piston chamber (30328) is set differently according to the required ratio, and the size of the matching piston body (30322) is different; According to the required proportion, the inlet pipe (30324) of one set of piston pumps (3032) is connected to the outlet pipe of the corresponding heat-insulated storage tank (301), and the inlet pipe (30324) of another set of piston pumps (3032) is connected to the outlet pipe of the corresponding heat-insulated storage tank (301). The outlet pipes (30325) of both sets of piston pumps (3032) are connected to the inlet pipe of the static mixer (400); The second drive device (3031) is poweredly connected to both sets of piston rods (30323).

8. The continuous preparation method of a formaldehyde-free flame-retardant adhesive according to claim 7, characterized in that, The top ends of both sets of piston rods (30323) are fixedly connected to traction frames (3033), and a sliding frame (3034) is fixedly connected to the equipment base frame (100). The traction frame (3033) is slidably connected to the sliding frame (3034). The second drive device (3031) cooperates with the traction frame (3033) so that the second drive device (3031) can pull the traction frame (3033) to perform reciprocating linear motion on the sliding frame (3034).

9. The continuous preparation method of a formaldehyde-free flame-retardant adhesive according to claim 8, characterized in that, The stirring assembly (302) includes a storage stirring paddle (3021), a second worm gear (3022), and a second worm wheel (3023). Each set of insulated storage tanks (301) is rotatably connected to the storage stirring paddle (3021). Each set of storage stirring paddles (3021) is fixedly connected to the second worm wheel (3023). Each set of insulated storage tanks (301) is rotatably connected to the second worm gear (3022). The second worm gear (3022) is meshed with the corresponding second worm wheel (3023). The second drive device (3031) is poweredly connected to the two sets of second worm gears (3022).

10. The continuous preparation method of a formaldehyde-free flame-retardant adhesive according to claim 9, characterized in that, The two sets of second worm gears (3022) are fixedly connected by a connecting shaft (3024). A gear (3025) is fixedly connected to the connecting shaft (3024), and a rack (3026) is fixedly connected to the traction frame (3033). The rack (3026) meshes with the gear (3025).

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