A fast-curing EVA hot melt adhesive and its preparation process

Abstract

The present invention belongs to the technical field of polymer binders. More specifically, it relates to a rapidly curing EVA hot melt adhesive and its preparation process. The product prepared by the present invention comprises raw materials in the following parts by weight: 150 - 160 parts of EVA resin, 100 - 110 parts of tackifying resin, 30 - 40 parts of wax, 10 - 12 parts of antioxidant and 30 - 35 parts of filler; the filler comprises island-coated carbonized bagasse fibers; the preparation steps of the island-coated carbonized bagasse fibers include: dispersing bagasse fibers in an ethanol solution, adjusting the pH to 7.5 - 8.0, then dropwise adding a silane coupling agent under stirring, heating and stirring for reaction, then dropwise adding tetraethyl orthosilicate, continuing heating and stirring for reaction, after the reaction ends, filtering, washing and drying to obtain a precursor; heating the obtained precursor at a rate of 6 - 8 °C / min to 380 - 400 °C, then heating at a rate of 0.9 - 1.5 °C / min to 880 - 900 °C, maintaining the temperature for carbonization, cooling, and discharging to obtain the island-coated carbonized bagasse fibers.

Description

Technical Field

[0001] The present invention belongs to the technical field of polymer adhesives and more specifically relates to a fast-curing EVA hot melt adhesive and a preparation process thereof. Background Art

[0002] EVA hot melt adhesive is a thermoplastic adhesive with ethylene-vinyl acetate copolymer (EVA) as its main component. It is solid at room temperature and melts into liquid when heated to a certain temperature. It has good fluidity and viscosity and is used to bond various materials. EVA hot melt adhesive has the following characteristics:

[0003] High bond strength: EVA hot melt adhesive provides strong adhesion and is suitable for a variety of substrates such as paper, plastic, metal and wood.

[0004] High initial adhesion: It has good initial adhesion and bonds quickly without the need for additional curing or drying process.

[0005] Temperature resistance: EVA hot melt adhesive is resistant to high temperatures and can maintain its bonding properties at higher temperatures. The temperature resistance range is usually between -30℃ and 80℃.

[0006] Weather resistance: It is not easily affected by moisture, aging or decomposition, making it suitable for outdoor applications and long-term use.

[0007] Environmental protection: EVA hot melt adhesive is solvent-free, non-toxic, has no pollution to the environment, and meets environmental protection requirements.

[0008] Good flexibility: EVA hot melt adhesive has good flexibility, is not easy to break and become brittle, and is suitable for applications that require bending or bearing pressure.

[0009] To increase the curing speed of EVA resin, methods typically include reducing the VA (vinyl acetate) content, adding tackifiers with high softening points, or adding waxes. However, all of these methods can lead to a decrease in the adhesive properties of EVA hot melt adhesives. Therefore, how to increase the curing speed while maintaining good adhesive properties remains a challenge for those skilled in the art. Summary of the Invention

[0010] The technical problem to be solved by the present invention is that in the commonly used EVA hot melt adhesive system, in order to obtain a faster curing rate, it is often difficult to take into account its good bonding performance. The present invention provides a fast-curing EVA hot melt adhesive and a preparation process thereof.

[0011] The invention aims to provide a fast-curing EVA hot-melt adhesive.

[0012] Another object of the present invention is to provide a preparation process for a fast-curing EVA hot-melt adhesive.

[0013] The above object of the present invention is achieved by the following technical solutions:

[0014] A fast-curing EVA hot melt adhesive, comprising the following raw materials in parts by weight:

[0015] 150 - 160 parts of EVA resin, 100 - 110 parts of tackifying resin, 30 - 40 parts of wax, 10 - 12 parts of antioxidant and 30 - 35 parts of filler;

[0016] The filler includes carbonized bagasse fibers with island-like coating;

[0017] The preparation steps of the carbonized bagasse fibers with island-like coating include:

[0018] Disperse bagasse fibers in an ethanol solution, adjust the pH to 7.5 - 8.0, then dropwise add a silane coupling agent under stirring, heat and stir for reaction, then dropwise add tetraethyl orthosilicate, continue to heat and stir for reaction after dropping, filter, wash and dry after the reaction ends to obtain a precursor;

[0019] Heat the obtained precursor at a rate of 6 - 8 °C / min to 380 - 400 °C, then heat at a rate of 0.9 - 1.5 °C / min to 880 - 900 °C, keep warm for carbonization, cool, and discharge to obtain the carbonized bagasse fibers with island-like coating.

[0020] In the above solution, by introducing self-made carbonized bagasse fibers with island-like coating as a filler into the EVA resin system and defining the corresponding preparation process of the carbonized bagasse fibers with island-like coating, in the above preparation process, first, under alkaline conditions, the silane coupling agent hydrolyzes and adsorbs on the surface of the bagasse fibers. On this basis, tetraethyl orthosilicate is further added to hydrolyze it, and the hydrolysis product is adsorbed and fixed on the surface of the bagasse fibers under the action of the silane coupling agent. Subsequently, the bagasse fibers are carbonized by heating. In this process, first, the water is removed by a rapid heating rate, and then the heating rate is significantly slowed down. During the slow heating process, the surface of the bagasse fibers coated with the hydrolysis product of tetraethyl orthosilicate can rely on its certain supporting effect. Therefore, due to the inconsistent stress in different parts, the bagasse fibers will be twisted to a certain extent. Thus, after carbonization, the bagasse fibers can obtain ideal mechanical strength and be dispersed in a twisted shape. In this way, it is beneficial to easily form physical entanglement between its molecular chains and the EVA resin, thereby enhancing the bonding strength between the two, improving the cohesion, ensuring the bonding performance of the product, and at the same time increasing the crystallization rate of the EVA resin molecules after melting, accelerating the curing process of the product. Therefore, the product can have good bonding performance and fast-curing ability at the same time.

[0021] Further, the aspect ratio of the bagasse fiber is (20 - 25):1, and the diameter of the bagasse fiber is 8 - 12 μm.

[0022] The inventors further found that by selecting bagasse fibers with a relatively larger aspect ratio, during the heating and carbonization process, they tend to form longer and thinner carbonized products. In this way, multiple molecular chains of EVA are easily entangled on the surface of the same carbonized bagasse fiber, thus forming continuous interaction forces. More importantly, when the longer and thinner bagasse fibers are structurally distorted under thermal stress, they easily form a three-dimensional twisted helical structure, which can avoid relative slippage between the carbonized bagasse fibers and the EVA molecular chains when subjected to external forces, thereby further enhancing the adhesion of the product.

[0023] Further, the silane coupling agent is selected from any one of silane coupling agent KH-550, silane coupling agent KH-560, and silane coupling agent KH-570.

[0024] Further, the dosage of the silane coupling agent is 3 - 5% of the mass of the bagasse fiber; and the dosage of the tetraethyl orthosilicate is 6 - 8% of the mass of the bagasse fiber.

[0025] By regulating the dosages of the above two raw materials, it is mainly considered that with a small amount of silane coupling agent, only local adsorption occurs on the surface of the bagasse fiber. Thus, the amount of tetraethyl orthosilicate is also relatively small. Under this ratio, corresponding island-like distributions can be formed, thereby creating a greater difference in stress between different parts and promoting the formation of a twisted state during the heating and carbonization process of the product.

[0026] Further, in the EVA resin, the mass content of VA is 28 - 32%; and the melt index of the EVA resin is 100 - 150.

[0027] Further, the tackifying resin is selected from any one of rosin glyceride, hydrogenated rosin resin, α-terpene resin, lemon terpene resin, C5 petroleum resin, and C5 hydrogenated petroleum resin.

[0028] Further, the wax is selected from any one of Fischer-Tropsch wax, polyethylene wax, microcrystalline wax, and paraffin wax.

[0029] Further, the antioxidant is selected from any one of antioxidant 264 and antioxidant 1010.

[0030] A preparation process for a fast-curing EVA hot melt adhesive, the specific preparation steps include:

[0031] Weigh each component according to the raw material composition;

[0032] At a temperature of 170 - 175 °C, first mix the tackifying resin and the filler, and after uniformly mixing them by low-speed shearing, then add wax, antioxidant, and EVA resin, continue heating and rapidly stir to mix evenly, and discharge to obtain the fast-curing EVA hot melt adhesive.

[0033] Furthermore, the uniform mixing by low-speed shearing includes: under the condition of a shearing rate of 160 - 180 r / min, continuously shear and mix for 30 - 45 min; and, the uniform mixing by heating and rapid stirring includes: under the condition of a stirring speed of 800 - 900 r / min, rapidly stir and mix for 20 - 30 min.

[0034] By first adopting a lower shearing rate, first melt the tackifying resin and then mix it with the filler. In this process, since the tackifying resin still maintains a relatively high viscosity after melting, thus, during the low-speed shearing process, with the action of physical shear force, the physical structure of the carbonized bagasse fibers of the filler can be fully unfolded, so as to avoid especially the problem that the molecular chains of the overly twisted long and slender bagasse fibers are excessively piled up together and thus difficult to disperse in the system. Specific embodiments

[0035] The following further illustrates the present invention in conjunction with specific embodiments, but the embodiments do not limit the present invention in any form. Unless otherwise specified, the reagents, methods, and equipment used in the present invention are conventional reagents, methods, and equipment in the technical field. <{

[0036] Unless otherwise specified, the reagents and materials used in the following embodiments are all commercially available.

[0037] Example 1

[0038] Preparation of island-coated carbonized bagasse fibers:

[0039] Mix bagasse fibers and an ethanol solution with a mass fraction of 30% according to a mass ratio of 1:8, adjust the pH to 7.5, then at a temperature of 40 °C and a stirring speed of 300 r / min, while stirring, dropwise add a silane coupling agent at a rate of 8 mL / min. After the silane coupling agent is added dropwise, continue heating and stirring for reaction for 30 min, then continue stirring and dropwise add tetraethyl orthosilicate at a rate of 8 mL / min. After tetraethyl orthosilicate is added dropwise, continue heating and stirring for reaction for 40 min. After the reaction ends, filter, collect the filter cake, wash the filter cake 2 times with deionized water, then transfer the washed filter cake to an oven for drying, and dry it at a temperature of 100 °C until a constant weight is obtained to obtain the precursor;

[0040] Among them, the aspect ratio of the bagasse fibers is 20:1, and the diameter of the bagasse fibers is 8 μm;

[0041] The silane coupling agent is selected from silane coupling agent KH-550;

[0042] The dosage of the silane coupling agent is 3% of the mass of the bagasse fiber; and the dosage of the tetraethyl orthosilicate is 6% of the mass of the bagasse fiber;

[0043] Transfer the obtained precursor into a carbonization furnace. Under the condition of an argon atmosphere, heat the obtained precursor at a rate of 6 °C / min to 380 °C, then keep it for heat treatment for 1 h, and then heat it at a rate of 0.9 °C / min to 880 °C, keep it for carbonization for 2 h, cool it with the furnace to room temperature, and discharge it to obtain island-shaped coated carbonized bagasse fiber, which is the filler;

[0044] Preparation of hot melt adhesive:

[0045] By weight, take 150 parts of EVA resin, 100 parts of tackifying resin, 30 parts of wax, 10 parts of antioxidant and 30 parts of island-shaped coated carbonized bagasse fiber in sequence;

[0046] In the EVA resin, the mass content of VA is 28%; and the melt index of the EVA resin is 100;

[0047] The tackifying resin is selected from rosin glyceride;

[0048] The wax is selected from Fischer-Tropsch wax;

[0049] The antioxidant is selected from antioxidant 264;

[0050] At a temperature of 170 °C, first mix the tackifying resin and the filler, and under the condition of a shear rate of 160 r / min, continuously shear and mix for 30 min, then add the wax, antioxidant and EVA resin, and continue to quickly stir and mix for 20 min under the condition of a stirring speed of 800 r / min, discharge and cool to obtain a fast-curing EVA hot melt adhesive.

[0051] Example 2

[0052] Preparation of island-shaped coated carbonized bagasse fiber:

[0053] Mix bagasse fibers and an ethanol solution with a mass fraction of 35% at a mass ratio of 1:9, adjust the pH to 7.8, and then, under the conditions of a temperature of 40 °C and a stirring speed of 350 r / min, add a silane coupling agent dropwise at a rate of 9 mL / min while stirring. After the silane coupling agent is added dropwise, continue heating and stirring for 35 min, and then, while still stirring, add tetraethyl orthosilicate dropwise at a rate of 9 mL / min. After tetraethyl orthosilicate is added dropwise, continue heating and stirring for 50 min. After the reaction ends, filter, collect the filter cake, wash the filter cake 3 times with deionized water, and then transfer the washed filter cake to an oven for drying. Dry it at a temperature of 100 °C until a constant weight is reached to obtain a precursor;

[0054] Among them, the aspect ratio of the bagasse fibers is 22:1, and the diameter of the bagasse fibers is 10 μm;

[0055] The silane coupling agent is selected from silane coupling agent KH-560;

[0056] The dosage of the silane coupling agent is 4% of the mass of the bagasse fibers; and the dosage of the tetraethyl orthosilicate is 7% of the mass of the bagasse fibers;

[0057] Transfer the obtained precursor to a carbonization furnace. Under an argon atmosphere, heat the obtained precursor at a rate of 7 °C / min to 390 °C, hold for heat treatment for 1.5 h, then heat at a rate of 1.2 °C / min to 890 °C, hold for carbonization for 3 h, and cool to room temperature with the furnace, and discharge to obtain island-shaped coated carbonized bagasse fibers, which are fillers;

[0058] Preparation of hot melt adhesive:

[0059] By weight, sequentially take 155 parts of EVA resin, 105 parts of tackifying resin, 35 parts of wax, 11 parts of antioxidant, and 32 parts of island-shaped coated carbonized bagasse fibers;

[0060] In the EVA resin, the mass content of VA is 30%; and the melt index of the EVA resin is 120;

[0061] The tackifying resin is selected from α-terpene resin;

[0062] The wax is selected from polyethylene wax;

[0063] The antioxidant is selected from antioxidant 1010;

[0064] At a temperature of 172 °C, first mix the tackifying resin and the filler, and under the condition of a shear rate of 170 r / min, continuously shear and mix for 35 min. Subsequently, add wax, antioxidant, and EVA resin, and continue to rapidly stir and mix for 25 min under the condition of a stirring speed of 850 r / min. Then discharge the material and cool it to obtain the fast-curing EVA hot-melt adhesive.

[0065] Example 3

[0066] Preparation of island-coated carbonized bagasse fibers:

[0067] Mix bagasse fibers and an ethanol solution with a mass fraction of 40% at a mass ratio of 1:10, adjust the pH to 8.0, and then at a temperature of 40 °C and a stirring speed of 400 r / min, while stirring, dropwise add a silane coupling agent at a rate of 10 mL / min. After the silane coupling agent is added dropwise, continue to heat and stir the reaction for 45 min, and then continue to dropwise add tetraethyl orthosilicate at a rate of 10 mL / min under stirring. After tetraethyl orthosilicate is added dropwise, continue to heat and stir the reaction for 60 min. After the reaction is completed, filter, collect the filter cake, wash the filter cake 4 times with deionized water, and then transfer the washed filter cake to an oven for drying. Dry it at a temperature of 100 °C until a constant weight is obtained to obtain the precursor;

[0068] Among them, the aspect ratio of the bagasse fibers is 25:1, and the diameter of the bagasse fibers is 12 μm;

[0069] The silane coupling agent is selected from silane coupling agent KH-570;

[0070] The dosage of the silane coupling agent is 5% of the mass of the bagasse fibers; and the dosage of the tetraethyl orthosilicate is 8% of the mass of the bagasse fibers;

[0071] Transfer the obtained precursor into a carbonization furnace. Under the condition of an argon atmosphere, heat and raise the temperature of the obtained precursor to 400 °C at a rate of 8 °C / min, keep it for heat treatment for 2 h, and then heat and raise the temperature to 900 °C at a rate of 1.5 °C / min, keep it for carbonization for 4 h, and cool it to room temperature with the furnace, discharge the material, and obtain the island-coated carbonized bagasse fibers, which are the filler;

[0072] Preparation of hot-melt adhesive:

[0073] By weight, sequentially take 160 parts of EVA resin, 110 parts of tackifying resin, 40 parts of wax, 12 parts of antioxidant, and 35 parts of island-coated carbonized bagasse fibers;

[0074] In the EVA resin, the mass content of VA is 32%; and the melt index of the EVA resin is 150;

[0075] The tackifying resin is selected from C5 hydrogenated petroleum resin;

[0076] The wax is selected from microcrystalline wax;

[0077] The antioxidant is selected from antioxidant 264;

[0078] At a temperature of 175 °C, first mix the tackifying resin and the filler, and under the condition of a shear rate of 180 r / min, continuously shear and mix for 45 min. Subsequently, add the wax, antioxidant and EVA resin, and continue to rapidly stir and mix for 30 min under the condition of a stirring speed of 900 r / min. Then discharge and cool to obtain the fast-curing EVA hot melt adhesive.

[0079] Example 4

[0080] Compared with Example 1, the difference in this example is that: the dosage of the silane coupling agent is 8% of the mass of the bagasse fiber; and the dosage of the tetraethyl orthosilicate is 12% of the mass of the bagasse fiber, and the other conditions remain unchanged.

[0081] Example 5

[0082] Compared with Example 1, the difference in this example is that: the aspect ratio of the bagasse fiber is 12:1, and the diameter of the bagasse fiber is 8 μm; and the other conditions remain unchanged.

[0083] Example 6

[0084] Compared with Example 1, the difference in this example is that:

[0085] Preparation of the hot melt adhesive:

[0086] By weight, sequentially take 150 parts of EVA resin, 100 parts of tackifying resin, 30 parts of wax, 10 parts of antioxidant, and 30 parts of island-coated carbonized bagasse fiber;

[0087] In the EVA resin, the mass content of VA is 28%; and the melt index of the EVA resin is 100;

[0088] The tackifying resin is selected from rosin glyceride;

[0089] The wax is selected from Fischer-Tropsch wax;

[0090] The antioxidant is selected from antioxidant 264;

[0091] At a temperature of 170 °C, mix the tackifying resin, filler, wax, antioxidant and EVA resin under the condition of a stirring speed of 800 r / min, rapidly stir and mix for 50 min, then discharge and cool to obtain the fast-curing EVA hot melt adhesive;

[0092] The other conditions remain unchanged.

[0093] Comparative Example 1

[0094] The difference between this comparative example and Example 1 is as follows:

[0095] Preparation of island-coated carbonized bagasse fibers:

[0096] After mixing bagasse fibers and an ethanol solution with a mass fraction of 30% at a mass ratio of 1:8, the pH was adjusted to 7.5, and then at a temperature of 40 °C and a stirring speed of 300 r / min, a silane coupling agent was added dropwise at a rate of 8 mL / min while stirring. After the addition of the silane coupling agent was completed, the mixture was continuously heated and stirred for reaction for 30 min. After the reaction ended, filtration was carried out, the filter cake was collected, and the filter cake was washed 2 times with deionized water. Then the washed filter cake was transferred to an oven for drying and dried to a constant weight at a temperature of 100 °C to obtain a precursor;

[0097] Among them, the aspect ratio of the bagasse fibers is 20:1, and the diameter of the bagasse fibers is 8 μm;

[0098] The silane coupling agent is selected from silane coupling agent KH-550;

[0099] The dosage of the silane coupling agent is 3% of the mass of the bagasse fibers; and the dosage of tetraethyl orthosilicate is 6% of the mass of the bagasse fibers;

[0100] The obtained precursor was transferred into a carbonization furnace. Under an argon atmosphere, the obtained precursor was heated and raised to 380 °C at a rate of 6 °C / min, then heat-treated at a constant temperature for 1 h, and then heated and raised to 880 °C at a rate of 0.9 °C / min, and carbonized at a constant temperature for 2 h, and then cooled to room temperature with the furnace, and the material was discharged to obtain island-coated carbonized bagasse fibers, which were used as fillers;

[0101] Other conditions remained unchanged.

[0102] Comparative Example 2

[0103] The difference between this comparative example and Example 1 is as follows:

[0104] Preparation of island-coated carbonized bagasse fibers:

[0105] Mix bagasse fiber and ethanol solution with a mass fraction of 30% at a mass ratio of 1:8, adjust the pH to 7.5, and then, under the conditions of a temperature of 40 °C and a stirring speed of 300 r / min, dropwise add a silane coupling agent at a rate of 8 mL / min while stirring. After the silane coupling agent is completely added, continue heating and stirring for 30 min, and then, while still stirring, dropwise add tetraethyl orthosilicate at a rate of 8 mL / min. After tetraethyl orthosilicate is completely added, continue heating and stirring for 40 min. After the reaction ends, filter, collect the filter cake, wash the filter cake twice with deionized water, then transfer the washed filter cake to an oven for drying, and dry it at a temperature of 100 °C until a constant weight is obtained to obtain a precursor;

[0106] Among them, the aspect ratio of the bagasse fiber is 20:1, and the diameter of the bagasse fiber is 8 μm;

[0107] The silane coupling agent is selected from silane coupling agent KH-550;

[0108] The dosage of the silane coupling agent is 3% of the mass of the bagasse fiber; and the dosage of the tetraethyl orthosilicate is 6% of the mass of the bagasse fiber;

[0109] Transfer the obtained precursor to a carbonization furnace, and under an argon atmosphere, heat and raise the temperature of the obtained precursor to 880 °C at a rate of 6 °C / min, keep it warm and carbonize for 2 h, cool it to room temperature with the furnace, and discharge it to obtain carbonized bagasse fiber with island-like coating, which is the filler;

[0110] Keep the other conditions unchanged.

[0111] Conduct relevant performance tests on the products obtained in the above examples and comparative examples. The specific test methods and test results are as follows:

[0112] Soak and polish a 100 mm × 50 mm × 1 mm stainless steel sheet with ethanol, dry it, etc., and set it aside. Then, use the EVA hot melt adhesive prepared in the above example or comparative example to bond the two steel sheets together, where the size of the middle bonding area is 20 mm × 20 mm and the coating thickness is 0.6 mm. Ensure that the thickness of the adhesive layer is uniform during coating. After the specimen is bonded, place it on a closed electric furnace at 80 °C, apply pressure with a 500 g weight, and place it for about 30 min. Then, use a knife to clean the adhesive overflowing around the bonding area. After cooling for 10 min, according to the test requirements of the performance indicators, use a ZQS6-2000A type bonding strength detector to conduct a shear strength test on the specimen according to the GB / T 7124-2008 standard to obtain a shear strength 1;

[0113] After soaking and polishing a 100mm×50mm×1mm stainless steel sheet in ethanol, it was dried and so on for standby. Then, the two steel sheets were bonded together using the EVA hot melt adhesive prepared in the above-mentioned examples or comparative examples, where the size of the central bonding area was 20mm×20mm and the glue coating thickness was 0.6mm. When applying the glue, it was necessary to ensure that the thickness of the glue layer was uniform. After the specimen was bonded, it was placed on a closed electric furnace at 80°C and pressed with a 500g weight for about 15 minutes. Then, a small knife was used to clean the glue overflowing around the bonding area. After cooling for 5 minutes, according to the test requirements of the performance indicators, a ZQS6-2000A type bonding strength detector was used to test the shear strength of the specimen according to the GB / T 7124-2008 standard, and the shear strength 2 was obtained.

[0114] The detailed test results are shown in Table 1;

[0115] Table 1: Test Results of Product Shear Strength

[0116]

[0117]

[0118] As can be seen from the test results in Table 1, the product obtained by the present invention has excellent shear strength, and moreover, even within a relatively short curing time, excellent bonding performance can still be obtained, effectively taking into account both the bonding performance and the rapid curing ability of the product.

[0119] The above embodiments are preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the above embodiments. Any other changes, modifications, substitutions, combinations, and simplifications made without departing from the spirit and principle of the present invention shall be equivalent replacement methods and are all included in the protection scope of the present invention.

Claims

1. A fast-curing EVA hot melt adhesive, characterized in that, It includes raw materials in the following parts by weight: 150 - 160 parts of EVA resin, 100 - 110 parts of tackifying resin, 30 - 40 parts of wax, 10 - 12 parts of antioxidant and 30 - 35 parts of filler; The filler includes carbonized bagasse fibers with island - like coating; The preparation steps of the carbonized bagasse fibers with island - like coating include: Disperse bagasse fibers in an ethanol solution, adjust the pH to 7.5 - 8.0, then dropwise add a silane coupling agent under stirring, after heating and stirring reaction, dropwise add tetraethyl orthosilicate, after the addition is complete, continue heating and stirring reaction, after the reaction ends, filter, wash and dry to obtain a precursor; Heat the obtained precursor at a rate of 6 - 8 °C / min to 380 - 400 °C, then heat at a rate of 0.9 - 1.5 °C / min to 880 - 900 °C, keep the temperature for carbonization, cool, and discharge to obtain the carbonized bagasse fibers with island - like coating; The aspect ratio of the bagasse fibers is (20 - 25):1, and the diameter of the bagasse fibers is 8 - 12 μm.

2. The quick-curing EVA hot melt adhesive according to claim 1, characterized in that, The silane coupling agent is selected from any one of silane coupling agent KH - 550, silane coupling agent KH - 560, and silane coupling agent KH - 570.

3. A fast-curing EVA hot melt adhesive according to claim 1, characterized in that, The dosage of the silane coupling agent is 3 - 5% of the mass of the bagasse fibers; and the dosage of the tetraethyl orthosilicate is 6 - 8% of the mass of the bagasse fibers.

4. A rapid-curing EVA hot melt adhesive according to claim 1, characterized in that, In the EVA resin, the mass content of VA is 28 - 32%; and the melt index of the EVA resin is 100 - 150.

5. A fast-curing EVA hot melt adhesive according to claim 1, characterized in that, The tackifying resin is selected from any one of rosin glyceride, hydrogenated rosin resin, α - terpinene resin, lemon terpinene resin, C5 petroleum resin, and C5 hydrogenated petroleum resin.

6. The rapid-curing EVA hot melt adhesive according to claim 1, wherein The wax is selected from any one of Fischer - Tropsch wax, polyethylene wax, microcrystalline wax, and paraffin wax.

7. The fast-curing EVA hot melt adhesive according to claim 1, wherein The antioxidant is selected from any one of antioxidant 264 and antioxidant 1010.

8. A preparation process of a fast-curing EVA hot melt adhesive according to any one of claims 1-7, characterized in that, The specific preparation steps include: Weigh each component according to the raw material composition; At a temperature of 170 - 175 °C, first mix the tackifying resin and the filler, after low - speed shear mixing evenly, then add the wax, antioxidant and EVA resin, continue heating and rapidly stirring and mixing evenly, and discharge to obtain a fast - curing EVA hot - melt adhesive.

9. The preparation process of a fast-curing EVA hot melt adhesive according to claim 8, characterized in that, The low - speed shear mixing evenly includes: under the condition of a shear rate of 160 - 180 r / min, continuously shear - mix for 30 - 45 min; and the heating and rapid stirring and mixing evenly includes: under the condition of a stirring speed of 800 - 900 r / min, rapidly stir - mix for 20 - 30 min.

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