Preparation method of modified formaldehyde-free adhesive

Abstract

The invention discloses a preparation method of a modified formaldehyde-free adhesive, and relates to the technical field of preparation of modified formaldehyde-free adhesives. A supporting table, an outer cylinder, a vacuum pump, a buffeting type defoaming mechanism, a progressive defoaming mechanism and a pressure maintaining mechanism are matched to complete preparation of the modified formaldehyde-free adhesive, the buffeting type defoaming mechanism used for vibrating the adhesive to preliminarily remove bubbles is installed at the cavity bottom of the outer cylinder, and a single cylinder located on the lower portion is fixedly connected to the outer portion of a driving shaft through a connecting rod. The buffeting type defoaming mechanism and the gradual type defoaming mechanism are combined, large bubbles are removed through vibration, then the gradual type combined cylinder is used for spreading and thinning an adhesive layer by layer, centrifugal force is enhanced, small bubbles are rapidly discharged, it is ensured that defoaming is more comprehensive and thorough, meanwhile, the defoaming efficiency is improved, and meanwhile the defoaming effect is better. The progressive bubble removing mechanism is linked with the pressure maintaining mechanism, the vacuum degree is automatically adjusted when bubbles escape, the stable negative pressure environment is maintained, and it is guaranteed that the deep small bubbles are thoroughly discharged.

Description

Technical Field

[0001] The invention relates to the technical field of modified formaldehyde-free adhesive preparation, in particular to a method for preparing the modified formaldehyde-free adhesive. Background Art

[0002] Formaldehyde-free adhesive is an adhesive that does not contain formaldehyde or formaldehyde-releasing substances. Its purpose is to reduce the negative impact of formaldehyde used in traditional adhesives on the environment and human health. As people's attention to indoor air quality continues to increase, the demand for formaldehyde-free adhesives is growing, especially in furniture manufacturing, building materials, packaging materials and other fields. In the context of pursuing environmental protection and sustainable development, soy protein, as a natural renewable resource, has good biodegradability and low toxicity. It is becoming more and more common to prepare modified formaldehyde-free adhesives using soy protein isolate powder. Common methods for preparing modified formaldehyde-free adhesives include protein solution preparation, modifier addition, plasticizer addition, degassing treatment, curing agent addition and packaging and storage. Degassing treatment is one of the most important steps in the preparation of modified formaldehyde-free adhesives. The degassing adhesive can significantly improve the quality and performance of the adhesive.

[0003] However, the current degassing treatment methods mainly include vacuum static degassing and mechanical stirring. It often takes a long time to effectively remove the bubbles in the adhesive, and the degassing method is relatively single. For tiny bubbles, due to the high viscosity of the adhesive, the bubbles are easily trapped in the colloid. It is difficult to completely remove all bubbles by simply relying on mechanical stirring or vacuum degassing. The bubbles remaining in the colloid will cause the performance of the adhesive to deteriorate. Summary of the invention

[0004] The present invention provides a preparation method of a modified formaldehyde-free adhesive, which solves the problem that current degassing treatment methods mainly include vacuum static degassing and mechanical stirring, but these two methods usually take a long time to effectively remove bubbles in the adhesive, and the degassing means are single. Due to the high viscosity of the adhesive, small bubbles are easily trapped in the colloid, and it is difficult to completely remove all bubbles by mechanical stirring or vacuum degassing alone, resulting in a decrease in adhesive performance. In addition, in the existing vacuum degassing process, as bubbles continue to escape, the pressure in the vacuum barrel gradually decreases, and sufficient negative pressure cannot be maintained, especially deep small bubbles are difficult to discharge, which increases the risk of residual bubbles, and the technical problem of high operational complexity of frequently starting the vacuum pump or adjusting the vacuum degree.

[0005] The present invention provides a method for preparing a modified formaldehyde-free adhesive. The specific steps of the method for preparing the modified formaldehyde-free adhesive are as follows: S1. Preparation of protein solution: Dissolve soy protein isolate powder in deionized water in a certain proportion, stir until completely dissolved to form a uniform protein solution, and use a pH adjuster to adjust the pH value to alkaline to improve solubility and reaction activity.

[0006] S2. Adding modifier: slowly add a proper amount of polyphosphoric acid modifier to the protein solution while stirring to promote the chemical reaction between the protein and the modifier. After continuing to stir for a period of time, add nano-silica to further improve the mechanical strength and water resistance of the adhesive.

[0007] S3. Adding plasticizer: Add an appropriate amount of glycerin plasticizer to the mixed liquid after stirring in S2 to improve flexibility and processing performance, and stir thoroughly to ensure that all ingredients are evenly mixed.

[0008] S4, degassing treatment: Use the pH adjuster again to fine-tune the pH value of the solution to ensure that it is within the optimal range, and pass the adhesive mixed in step S3 into the outer cylinder for vacuum degassing, and then enter the dithering degassing mechanism and the progressive degassing mechanism in turn for further degassing treatment to remove bubbles therein and improve the quality of the adhesive.

[0009] S5. Adding curing agent: Add an appropriate amount of curing agent to the adhesive after degassing in step S4, stir thoroughly to ensure that all ingredients are evenly mixed, and obtain the desired modified formaldehyde-free adhesive.

[0010] S6. Packaging and storage: Fill the prepared modified formaldehyde-free adhesive into a sealed container and store it in a cool and dry place.

[0011] The steps of the method for preparing the modified formaldehyde-free adhesive in the above steps S1-S6 need to be completed by the support, the outer cylinder, the vacuum pump, the dithering defoaming mechanism, the progressive defoaming mechanism and the pressure-maintaining mechanism.

[0012] The upper end surface of the support platform is fixedly connected with an outer cylinder, a vacuum pump is arranged on the outer cylinder, a vibration defoaming mechanism for vibrating the adhesive to preliminarily remove bubbles is installed at the bottom of the outer cylinder cavity, a feeding pipe connected with the vibration defoaming mechanism is fixedly connected to the left part of the outer cylinder, a progressive defoaming mechanism for dispersing the adhesive and gradually removing the remaining bubbles is arranged inside the outer cylinder and above the vibration defoaming mechanism, a discharge mechanism for discharging the defoamed adhesive is arranged on the outer cylinder, and the progressive defoaming mechanism includes a mounting strip fixedly connected between the left and right cavity walls of the outer cylinder, a A driving shaft, a combined cylinder rotatably connected to the inner cavity of the outer cylinder through a support plate, a pumping portion jointly arranged at the lower part between the combined cylinder and the driving shaft, and a stirring portion arranged outside the driving shaft for stirring the adhesive entering the combined cylinder. A driving motor transmission-connected to the driving shaft is arranged on the upper cavity wall of the outer cylinder. The combined cylinder includes a plurality of single cylinders whose diameters increase equidistantly from bottom to top and are interconnected, and a material blocking assembly arranged on each single cylinder. The single cylinders are all sleeved on the outside of the driving shaft. The single cylinder located at the lower part is fixedly connected to the outside of the driving shaft by a connecting rod, and the inner cavity of the single cylinder gradually inclines toward the side close to the axis of the driving shaft from top to bottom.

[0013] In one possible implementation, the extraction part includes a sleeve fixedly connected to the left cavity wall of the outer cylinder through a cross bar and connected to the lower part of the combined cylinder, a prismatic rod fixedly connected to the lower end of the driving shaft, a sliding sleeve fixedly connected to the outside of the prismatic rod, a spiral paddle fixedly connected to the outside of the sliding sleeve, and an inner tube fixedly connected in the sleeve, and the sleeve is rotatably connected to the single cylinder located at the bottom.

[0014] In one possible implementation, the vibration defoaming mechanism includes two sliding rods that are symmetrically fixed to the bottom of the outer cylinder cavity through support blocks, the two sliding rods are slidably connected to the outside with sliding ear blocks, the sliding ear blocks and the sliding rods are commonly fixedly connected with a limiting spring, a material storage box is commonly fixedly connected between the sliding ear blocks, two L-shaped frames are symmetrically fixedly connected to the upper end front and rear of the support, a number of diverter plates are equidistantly fixedly connected to the lower end surface of the transverse section of the L-shaped frame and located in the material storage box, a vertical column is fixedly connected to the bottom of the material storage box cavity, and an arc-shaped diverter plate cooperating with the vertical column is fixedly connected to the outside of the prismatic rod.

[0015] In one possible implementation, the stirring part includes a driving sleeve rotatably connected to the outside of the driving shaft, and the outside of the driving sleeve is fixedly connected with a plurality of stirring rod groups corresponding to the single cylinder at equal distances along the axis, and the stirring rods are fixedly connected in a plurality of rows at equal distances along the circumferential outer wall of the driving sleeve.

[0016] In one possible implementation, the material blocking assembly includes a plurality of rotating columns equidistantly circumferentially penetrating and rotatably connected to the single cylinder, an end of the rotating column close to the center of the single cylinder is fixedly connected to an arc-shaped blocking bar, an end of the rotating column away from the single cylinder is fixedly connected to a No. 2 gear ring, a driving ring is slidably connected to the outside of the single cylinder, and a plurality of racks corresponding to and meshing with the No. 2 gear ring are fixedly connected to the upper part of the driving ring at equidistant circumference.

[0017] In one possible implementation, the lower end surface of the mounting strip is fixedly connected to a transmission box arranged outside the drive shaft and the driving shaft sleeve, a No. 1 gear ring is fixedly connected to the outside of the drive shaft and located in the transmission box, a transmission shaft is rotatably connected between the upper and lower cavity walls of the transmission box, a No. 2 gear ring meshing with the No. 1 gear ring is fixedly connected to the upper part of the outer wall of the transmission shaft, and a pulley assembly is commonly connected to the lower part of the transmission shaft and the driving shaft sleeve.

[0018] In one possible implementation, the discharge mechanism includes an annular collecting pipe that is fixedly connected to the inner cavity of the outer cylinder by a fixed column and movably sleeved on the outside of the single cylinder located at the upper part. The annular collecting pipe is in an inclined state with the left side higher and the right side lower. The right part of the annular collecting pipe is connected to a discharge pipe that passes through the outer cylinder.

[0019] It can be seen from the above technical solutions that the present invention has the following advantages: In the present invention, a dual defoaming mechanism of first vibrating and then centrifuging the bubbles in the adhesive is realized by combining a dithering defoaming mechanism and a progressive defoaming mechanism, which can quickly and effectively destroy and release large bubbles in the colloid. Then, the combined cylinder in the progressive defoaming mechanism is designed with a gradually increasing diameter from bottom to top, so that the adhesive is diluted layer by layer during the rotation process. The multi-stage design with gradually increasing diameter increases the multi-stage impact of the adhesive, which can accelerate the discharge of fine bubbles in the adhesive, making the defoaming process more comprehensive and thorough.

[0020] In the present invention, the progressive degassing mechanism and the pressure-maintaining mechanism are linked to each other, and the vacuum degree in the outer cylinder is automatically adjusted as the bubbles continue to escape during the degassing process, ensuring that the vacuum pressure will not drop, maintaining a stable negative pressure environment, and ensuring that the entire degassing process from beginning to end can be carried out under optimal conditions, thereby ensuring that small bubbles in the deep layer can also be completely discharged under the action of continuous negative pressure, and at the same time avoiding the step of frequently starting the vacuum pump to adjust the vacuum degree, thereby improving the degassing efficiency and effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying creative work.

[0022] Figure 1 This is a diagram of the preparation method of the modified formaldehyde-free adhesive provided by the present invention.

[0023] Figure 2 This is a schematic cross-sectional view of the overall structure provided by the present invention (the upper half of the annular collecting pipe is cut away).

[0024] Figure 3 This is a schematic diagram of the connection structure of the dithering defoaming mechanism and the progressive defoaming mechanism provided by the present invention.

[0025] Figure 4 This is a schematic cross-sectional structure diagram of the dithering defoaming mechanism provided by the present invention.

[0026] Figure 5 This is a schematic cross-sectional view of the connection structure of the progressive defoaming mechanism provided by the present invention (part of the material blocking component is hidden).

[0027] Figure 6 This is a schematic diagram of the installation structure of the material blocking assembly provided by the present invention.

[0028] Figure 7 The present invention provides Figure 6 Schematic diagram of the enlarged structure of part A in the figure.

[0029] Figure 8 This is a schematic diagram of the cross-sectional structure of the discharge mechanism provided by the present invention from a front view perspective.

[0030] Fig. 9 This is a schematic cross-sectional view from the front perspective of the transmission box installation structure provided by the present invention.

[0031] The above drawings include the following reference numerals: 1. Support platform; 2. Outer cylinder; 3. Vacuum pump; 4. Dithering defoaming mechanism; 41. Sliding rod; 42. Sliding ear block; 43. Material storage box; 44. Flow-diverting plate; 45. Vertical column; 46. Arc-shaped toggle plate; 5. Progressive defoaming mechanism; 51. Mounting strip; 52. Driving shaft; 53. Combination cylinder; 531. Single cylinder; 532. Material blocking assembly; 5321. Rotating column; 5322. Arc-shaped blocking strip; 5323. Second gear ring; 5324 , drive ring; 5325, rack; 54, extraction part; 541, sleeve; 542, prismatic rod; 543, sleeve; 544, spiral paddle; 545, inner tube; 55, stirring part; 551, driving sleeve; 552, stirring rod group; 6, driving motor; 7, discharge mechanism; 71, annular collecting pipe; 72, discharge pipe; 8, transmission box; 9, gear ring No. 1; 10, transmission shaft; 11, gear ring No. 2; 12, pulley assembly. DETAILED DESCRIPTION

[0032] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific embodiments of the present invention are described in detail below in conjunction with the accompanying drawings. In the following description, many specific details are set forth to facilitate a full understanding of the present invention. However, the present invention can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without violating the connotation of the present invention, so the present invention is not limited by the specific embodiments disclosed below.

[0033] See also Figure 1 and Figure 2 The present invention provides a technical solution: a method for preparing a modified formaldehyde-free adhesive. The specific steps of the method for preparing the modified formaldehyde-free adhesive are as follows: S1. Preparation of protein solution: Dissolve soy protein isolate powder in deionized water in a certain proportion, stir until completely dissolved to form a uniform protein solution, and use a pH adjuster to adjust the pH value to alkaline to improve solubility and reaction activity.

[0034] S2. Adding modifier: slowly add a proper amount of polyphosphoric acid modifier to the protein solution while stirring to promote the chemical reaction between the protein and the modifier. After continuing to stir for a period of time, add nano-silica to further improve the mechanical strength and water resistance of the adhesive.

[0035] S3. Adding plasticizer: Add an appropriate amount of glycerin plasticizer to the mixed liquid after stirring in S2 to improve flexibility and processing performance, and stir thoroughly to ensure that all ingredients are evenly mixed.

[0036] S4, degassing treatment: Use the pH adjuster again to fine-tune the pH value of the solution to ensure that it is within the optimal range, and pass the adhesive mixed in step S3 into the outer cylinder 2 for vacuum degassing, and then enter the vibration degassing mechanism 4 and the progressive degassing mechanism 5 in turn for further degassing treatment to remove bubbles therein and improve the quality of the adhesive.

[0037] S5. Adding curing agent: Add an appropriate amount of curing agent to the adhesive after degassing in step S4, stir thoroughly to ensure that all ingredients are evenly mixed, and obtain the desired modified formaldehyde-free adhesive.

[0038] S6. Packaging and storage: Fill the prepared modified formaldehyde-free adhesive into a sealed container and store it in a cool and dry place.

[0039] The steps of the method for preparing the modified formaldehyde-free adhesive in the above steps S1-S6 need to be completed by the support 1, the outer cylinder 2, the vacuum pump 3, the dithering defoaming mechanism 4, the progressive defoaming mechanism 5 and the pressure-maintaining mechanism 6.

[0040] An outer cylinder 2 is fixedly connected to the upper end surface of the support 1, a vacuum pump 3 is arranged on the outer cylinder 2, a vibration defoaming mechanism 4 for vibrating the adhesive to preliminarily remove bubbles is installed at the bottom of the cavity of the outer cylinder 2, a feed pipe connected to the vibration defoaming mechanism 4 is fixedly connected to the left part of the outer cylinder 2, a progressive defoaming mechanism 5 for dispersing the adhesive and gradually removing residual bubbles is arranged inside the outer cylinder 2 and above the vibration defoaming mechanism 4, a pressure maintaining mechanism 6 for continuously ensuring the vacuum pressure inside the outer cylinder 2 is installed on the upper part of the outer cylinder 2, and a discharge mechanism 7 for discharging the defoamed adhesive is arranged on the outer cylinder 2.

[0041] See also Figure 2 and Figure 5 In this embodiment, the progressive defoaming mechanism 5 includes a mounting strip 51 fixedly connected between the left and right cavity walls of the outer cylinder 2, a driving shaft 52 that penetrates and is rotatably connected to the mounting strip 51, a combination cylinder 53 that is rotatably connected to the inner cavity of the outer cylinder 2 through a support plate, a pumping portion 54 that is jointly arranged at the lower part between the combination cylinder 53 and the driving shaft 52, and a stirring portion 55 that is arranged outside the driving shaft 52 and is used to stir the adhesive entering the combination cylinder 53. A driving motor 6 that is transmission-connected to the driving shaft 52 is arranged on the upper cavity wall of the outer cylinder (2) (wherein the driving force of the driving motor 6 fully meets the requirements of this patent application), the support plate is fixedly connected between the left and right cavity walls of the outer cylinder 2, and the combination cylinder 53 is rotatably connected to the support plate.

[0042] See also Figure 3 and Figure 4 The extraction part 54 includes a prismatic rod 542 fixedly connected to the lower end of the driving shaft 52, the vibration defoaming mechanism 4 includes two sliding rods 41 fixedly connected to the bottom of the outer cylinder 2 by a support block, the two sliding rods 41 are slidably connected to the outside with sliding ear blocks 42, the sliding ear blocks 42 and the sliding rods 41 are jointly fixedly connected with a limiting spring, and a material storage box 43 is jointly fixedly connected between the sliding ear blocks 42, and two L-shaped frames are symmetrically fixedly connected to the front and rear of the upper end face of the support platform 1, and a plurality of diverter plates 44 are fixedly connected to the lower end face of the transverse section of the L-shaped frame and are located in the material storage box 43 at an equidistant distance, and a vertical column 45 is fixedly connected to the bottom of the cavity of the material storage box 43, and an arc-shaped diverter plate 46 cooperating with the vertical column 45 is fixedly connected to the outside of the prismatic rod 542.

[0043] The adhesive to be degassed is introduced into the feed pipe through the input pump, and the adhesive then enters the storage box 43. When degassed, the vacuum pump 3 is first controlled to operate to draw the inner cavity of the outer cylinder 2 into a negative pressure vacuum state, and some large bubbles in the adhesive are removed by the vacuum. Then the drive motor 6 is controlled to drive the drive shaft 52 to rotate, and the drive shaft 52 then drives the prism rod 542 to rotate, and the prism rod 542 then drives the arc-shaped toggle piece 46 to rotate. When the arc-shaped toggle piece 46 rotates to contact with the vertical column 45, it will push the storage box 43 to move. (The arc-shaped toggle piece 46 is in contact with the vertical column 45 for a short length each time, which avoids the storage box The stroke of the material storage box 43 when it shakes is too large), when the arc-shaped toggle piece 46 separates from the vertical column 45, the limit spring pushes the material storage box 43 after the above-mentioned movement to move in the opposite direction until the arc-shaped toggle piece 46 rotates to contact with the vertical column 45 again, and the material storage box 43 will move again, and the intermittent contact and separation between the arc-shaped toggle piece 46 and the vertical column 45 drive the material storage box 43 to move back and forth, and the material storage box 43 then drives the adhesive placed inside it to shake, and the shaking adhesive then collides with the toggle piece 44, further aggravating the shaking amplitude of the adhesive, thereby discharging larger bubbles in the adhesive.

[0044] See also Figure 3 , Figure 4 and Figure 5 The drawer 53 is provided with a plurality of single barrels 531, each of which has a diameter that increases equidistantly from bottom to top and is interconnected, and a material stopper assembly 532 arranged on each single barrel 531. The single barrels 531 are all sleeved on the outside of the drive shaft 52. The single barrel 531 located at the lower part is fixedly connected to the outside of the drive shaft 52 by a connecting rod. The inner cavity of the single barrel 531 gradually inclines toward the axis side of the drive shaft 52 from top to bottom. The drawer 5 also includes a sleeve 541 fixedly connected to the left cavity wall of the outer barrel 2 by a cross bar and connected to the lower part of the drawer 53, a sleeve 543 fixedly connected to the outside of the prismatic rod 542, a spiral paddle 544 fixedly connected to the outside of the sleeve 543, and an inner tube 545 fixedly connected to the sleeve 541. The inner tube 545 and the sleeve 543 are coaxially arranged. The inner tube 545 does not contact the spiral paddle 544. The sleeve 541 is rotatably connected to the single barrel 531 located at the lower part.

[0045] See also Figure 5 , Figure 6 and Figure 7The material blocking assembly 532 includes a plurality of rotating columns 5321 which are circumferentially equidistantly penetrated and rotatably connected to the monocylinder 531, an end of the rotating column 5321 close to the center of the monocylinder 531 is fixedly connected with an arc-shaped retaining bar 5322, an end of the rotating column 5321 away from the monocylinder 531 is fixedly connected with a No. 2 gear ring 5323, a driving ring 5324 is slidably connected to the outside of the monocylinder 531, a plurality of racks 5325 corresponding to and meshing with the No. 2 gear ring 5323 are fixedly connected to the upper part of the driving ring 5324 at circumferentially equidistant, the stirring part 55 includes a driving sleeve 551 rotatably connected to the outside of the driving shaft 52, a plurality of stirring rod groups 552 corresponding to the monocylinder 531 are fixedly connected to the outside of the driving sleeve 551 at equidistant intervals along the axis line, and a plurality of rows of stirring rods are fixedly connected at equidistant intervals along the circumferential outer wall of the driving sleeve 551.

[0046] See also Fig. 9 The lower end surface of the mounting strip 51 is fixedly connected to a transmission box 8 arranged outside the driving shaft 52 and the driving shaft sleeve 551, and a first gear ring 9 is fixedly connected to the outside of the driving shaft 52 and located in the transmission box 8. A transmission shaft 10 is rotatably connected between the upper and lower cavity walls of the transmission box 8, and a second gear ring 11 meshing with the first gear ring 9 is fixedly connected to the upper part of the outer wall of the transmission shaft 10, and a pulley assembly 12 is commonly connected to the lower part of the transmission shaft 10 and the driving shaft sleeve 551.

[0047] As the prism rod 542 rotates, it drives the sliding sleeve 543 to rotate synchronously, and the sliding sleeve 543 then drives the spiral paddle 544 to rotate. As the spiral paddle 544 rotates, the adhesive is sucked into the inner tube 545 and flows from bottom to top, and the adhesive can be sucked into the combined tube 53.

[0048] The driving shaft 52 then drives the combined cylinder 53 to rotate as a whole through the connecting rod, and the single cylinder 531 in the combined cylinder 53 rotates synchronously. The centrifugal force during the rotation of the single cylinder 531 causes the adhesive entering the single cylinder 531 to be gradually thrown onto the cylinder wall, and then the adhesive gradually flows from bottom to top under the slope of the inner cavity cylinder wall of the single cylinder 531 to be diluted and dispersed. At the same time, the rotation of the driving shaft 52 drives the No. 1 gear ring 9 to rotate, and the No. 1 gear ring 9 then drives the transmission shaft 8 to rotate through the No. 2 gear ring 11, and the transmission shaft 8 then drives the No. 1 gear ring 9 to rotate. The pulley assembly 12 drives the driving sleeve 551 to rotate. The driving sleeve 551 rotates in the opposite direction to the driving shaft 52, and drives the stirring rod group 552 to rotate. The stirring rod group 552 then stirs the adhesive to further disperse the adhesive, causing the bubbles in the adhesive to burst and escape. The arc-shaped baffle 5322 in each single cylinder 531 is used to form a ring to block the upper part of the single cylinder 531 to temporarily block the adhesive entering the single cylinder 531, so that the adhesive stays in the single cylinder 531 for a sufficient period of time.

[0049] Then, the self-propelled driving ring 5324 is controlled to move upward, and the driving ring 5324 moves upward to drive the rack 5325 to rise, and the rack 5325 then drives the rotating column 5321 to rotate through the second gear ring 5323, and the rotating column 5321 further drives the arc-shaped baffle 5322 to rotate, and the arc-shaped baffle 5322 rotates until it becomes a vertical state, and then the adhesive gradually moves upward under the centrifugal force and the slope of the inner cavity wall of the single cylinder 531, until it completely flows into the second single cylinder 531 from the bottom, and then the driving ring 5324 is controlled to move downward and reset, and the driving ring 5324 The arc-shaped baffle 5322 is driven to reverse by the rack 5325, the second gear ring 5323 and the rotating column 5321, so that the arc-shaped baffle 5322 forms a ring again for blocking, and the above-mentioned degassing steps are repeated. The adhesive is gradually spread and impacted in multiple steps by utilizing the multi-step increase principle of the diameter of the single cylinder 531 and the action of centrifugal force, so that the bubbles in the adhesive quickly burst and escape. The single cylinder 531 with a gradually increasing diameter from bottom to top is subjected to a centrifugal rapid degassing treatment with multiple-step impacts to completely remove the bubbles in the adhesive.

[0050] See also Figure 2 , Figure 3 , Figure 5 and Figure 8 In this embodiment, the discharge mechanism 7 includes an annular collecting pipe 71 which is fixedly connected to the inner cavity of the outer cylinder 2 by a fixed column and movably sleeved on the outside of the single cylinder 531 located at the upper part. The annular collecting pipe 71 is in an inclined state with the left side higher and the right side lower. The right part of the annular collecting pipe 71 is connected with a discharge pipe 72 which runs through the outer cylinder 2. During the degassing process of the adhesive, the discharge pipe 72 is in a closed state under the action of an external valve body. After the combined cylinder 53 completes the degassing of the adhesive, the adhesive located in the uppermost single cylinder 531 will be thrown into the annular collecting pipe 71 by the action of the rotating centrifugal force of the single cylinder 531 (wherein the height of the annular collecting pipe 71 is relatively high, and there will be no situation where the adhesive is higher than the annular collecting pipe 71 and is thrown out), and then the adhesive gradually flows to the right under the inclined surface of the annular collecting pipe 71, and finally flows into the discharge pipe 72. Then, the valve body on the discharge pipe 72 is controlled to open, so that the adhesive after degassing can be discharged.

[0051] In the description of the present invention, it is to be understood that the terms “center”, “longitudinal”, “lateral”, “length”, “width”, “thickness”, “up”, “down”, “front”, “back”, “left”, “vertical”, “horizontal”, “top”, “bottom”, “inside”, “outside”, “clockwise”, “counterclockwise”, “axial”, “radial”, “circumferential”, etc., indicating orientations or positional relationships are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0052] In addition, the terms "first", "second", "number one", "number two" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first", "second", "number one", "number two" may explicitly or implicitly include at least one of the features. In the description of the present invention, the meaning of "multiple" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0053] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0054] The embodiments of this specific implementation method are all preferred embodiments of the present invention, and are not intended to limit the protection scope of the present invention. Therefore, all equivalent changes made based on the structure, shape, and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for preparing a modified formaldehyde-free adhesive, characterized in that: The specific steps of the preparation method of the modified formaldehyde-free adhesive are as follows: S1. Preparation of protein solution: dissolve soy protein isolate powder in deionized water according to a certain proportion, stir until completely dissolved to form a uniform protein solution, and use a pH regulator to adjust the pH value to alkaline to improve solubility and reaction activity; S2. Adding modifier: slowly add an appropriate amount of polyphosphoric acid modifier to the protein solution while stirring to promote the chemical reaction between the protein and the modifier. After continuing to stir for a period of time, add nano-silicon dioxide to further improve the mechanical strength and water resistance of the adhesive. S3, adding plasticizer: adding an appropriate amount of glycerin plasticizer to the mixed solution after stirring in S2 to improve flexibility and processing performance, and stirring thoroughly to ensure that all ingredients are evenly mixed; S4, degassing treatment: the pH value of the solution is fine-tuned again using a pH regulator to ensure that it is within the optimal range, and the adhesive mixed in step S3 is passed into the outer cylinder (2) for vacuum degassing, and then sequentially enters the dithering degassing mechanism (4) and the progressive degassing mechanism (5) for further degassing treatment to remove bubbles therein and improve the quality of the adhesive; S5, adding curing agent: adding an appropriate amount of curing agent to the adhesive after degassing in step S4, stirring thoroughly to ensure that all ingredients are evenly mixed to obtain the desired modified formaldehyde-free adhesive; S6. Packaging and storage: Fill the prepared modified formaldehyde-free adhesive into a sealed container and store it in a cool and dry place; The steps of the method for preparing the modified formaldehyde-free adhesive in the above steps S1 to S6 need to be completed by the support (1), the outer cylinder (2), the vacuum pump (3), the dithering defoaming mechanism (4), the progressive defoaming mechanism (5) and the pressure-maintaining mechanism (6); wherein: The upper end surface of the support platform (1) is fixedly connected to an outer cylinder (2), a vacuum pump (3) is arranged on the outer cylinder (2), a vibration defoaming mechanism (4) for vibrating the adhesive to preliminarily remove bubbles is installed at the bottom of the cavity of the outer cylinder (2), a feeding pipe connected to the vibration defoaming mechanism (4) is fixedly connected to the left part of the outer cylinder (2), a progressive defoaming mechanism (5) for dispersing the adhesive and gradually removing residual bubbles is arranged inside the outer cylinder (2) and above the vibration defoaming mechanism (4), and a discharge mechanism (7) for discharging the defoamed adhesive is arranged on the outer cylinder (2); The progressive defoaming mechanism (5) comprises a mounting strip (51) fixedly connected between the left and right cavity walls of the outer cylinder (2), a driving shaft (52) penetrating and rotatably connected to the mounting strip (51), a combination cylinder (53) rotatably connected to the inner cavity of the outer cylinder (2) through a support plate, a material extraction portion (54) jointly arranged at the lower part between the combination cylinder (53) and the driving shaft (52), and a stirring portion (55) arranged outside the driving shaft (52) for stirring the adhesive entering the combination cylinder (53), and a driving motor (6) drivingly connected to the driving shaft (52) is arranged on the upper cavity wall of the outer cylinder (2); The combined cylinder (53) comprises a plurality of single cylinders (531) whose diameters increase equidistantly from bottom to top and are interconnected, and a material blocking assembly (532) arranged on each single cylinder (531). The single cylinders (531) are all sleeved on the outside of the driving shaft (52). The single cylinder (531) located at the bottom is fixedly connected to the outside of the driving shaft (52) through a connecting rod. The inner cavity of the single cylinder (531) is gradually inclined from top to bottom towards the axis side of the driving shaft (52).

2. The method for preparing a modified formaldehyde-free adhesive according to claim 1, characterized in that: The extraction portion (54) comprises a sleeve (541) fixedly connected to the left cavity wall of the outer cylinder (2) through a cross bar and connected to the lower part of the combined cylinder (53), a prism rod (542) fixedly connected to the lower end of the driving shaft (52), a sliding sleeve (543) fixedly connected to the outside of the prism rod (542), a spiral paddle (544) fixedly connected to the outside of the sliding sleeve (543), and an inner tube (545) fixedly connected to the sleeve (541), and the sleeve (541) is rotatably connected to the single cylinder (531) located at the lower part.

3. The method for preparing a modified formaldehyde-free adhesive according to claim 2, characterized in that: The vibration defoaming mechanism (4) comprises two slide bars (41) which are symmetrically fixedly connected to the bottom of the outer cylinder (2) through support blocks, the two slide bars (41) are slidably connected to the outside with slide ear blocks (42), the slide ear blocks (42) and the slide bars (41) are commonly fixedly connected with a limit spring, the slide ear blocks (42) and the slide bars (41) are commonly fixedly connected with a material storage box (43), the upper end face of the support platform (1) is symmetrically fixedly connected with two L-shaped frames, the lower end face of the transverse section of the L-shaped frame is equidistantly fixedly connected with a plurality of diverter plates (44), the bottom of the material storage box (43) is fixedly connected with a vertical column (45), and the outside of the prism rod (542) is fixedly connected with an arc-shaped diverter plate (46) cooperating with the vertical column (45).

4. The method for preparing a modified formaldehyde-free adhesive according to claim 1, characterized in that: The stirring portion (55) comprises a driving shaft sleeve (551) rotatably connected to the outside of the driving shaft (52); a plurality of stirring rod groups (552) corresponding to the single cylinder (531) are fixedly connected to the outside of the driving shaft sleeve (551) at equal intervals along the axis; and a plurality of rows of stirring rods are fixedly connected at equal intervals along the circumferential outer wall of the driving shaft sleeve (551).

5. The method for preparing a modified formaldehyde-free adhesive according to claim 1, characterized in that: The material blocking assembly (532) includes a plurality of rotating columns (5321) equidistantly circumferentially penetrating and rotatably connected to the monocylinder (531), one end of the rotating column (5321) close to the center of the monocylinder (531) is fixedly connected with an arc-shaped blocking bar (5322), and one end of the rotating column (5321) away from the monocylinder (531) is fixedly connected with a second gear ring (5323), the outside of the monocylinder (531) is slidably connected with a driving ring (5324), and a plurality of racks (5325) corresponding to and meshing with the second gear ring (5323) are fixedly connected to the upper part of the driving ring (5324) at equidistant circumference.

6. The method for preparing a modified formaldehyde-free adhesive according to claim 4, characterized in that: The lower end surface of the mounting strip (51) is fixedly connected to a transmission box (8) arranged outside the drive shaft (52) and the drive shaft sleeve (551); a first gear ring (9) is fixedly connected outside the drive shaft (52) and located in the transmission box (8); a transmission shaft (10) is rotatably connected between the upper and lower cavity walls of the transmission box (8); a second gear ring (11) meshing with the first gear ring (9) is fixedly connected to the upper part of the outer wall of the transmission shaft (10); and a pulley assembly (12) is commonly connected to the lower part of the transmission shaft (10) and the drive shaft sleeve (551).

7. The method for preparing a modified formaldehyde-free adhesive according to claim 1, characterized in that: The discharge mechanism (7) comprises an annular collecting pipe (71) which is fixedly connected to the inner cavity of the outer cylinder (2) by a fixing column and movably sleeved on the outside of the single cylinder (531) located at the upper part. The annular collecting pipe (71) is in an inclined state with the left side higher and the right side lower. The right part of the annular collecting pipe (71) is connected to a discharge pipe (72) which passes through the outer cylinder (2).

Images