Cleaning material of screw barrel for injection molding machine and extruder and preparation method of cleaning material

Abstract

The invention relates to a cleaning material for a screw barrel for an injection molding machine and an extruder and a preparation method of the cleaning material, and belongs to the technical field of plastic processing. The cleaning material is prepared from the following components: 18 to 22 weight percent of friction filler, 4.2 to 5.5 weight percent of foaming cleaning aid, 0.8 to 1 weight percent of internal lubricant, 0.5 to 0.7 weight percent of compatilizer, 1.2 to 1.5 weight percent of surfactant, 1.5 to 2 weight percent of viscosity reducer, 0.1 to 0.13 weight percent of antioxidant and the balance of linear low-density polyethylene resin, according to the foaming cleaning auxiliary agent, potassium bicarbonate serves as a core material, an organic matter polymerization coating layer is formed on the surface in situ through a chemical reaction, efficient, low-consumption and deep screw cleaning is achieved through the triple effects of chemical chelation, dynamic foaming and physical scraping, and the core problems of insufficient cleaning capacity, high cost and large energy consumption in the prior art are solved.

Description

Technical Field

[0001] The present invention belongs to the technical field of plastic processing, and specifically relates to a cleaning material for the screw barrel of an injection molding machine and an extruder and a preparation method thereof. Background Art

[0002] In the field of plastic processing, the cleaning of the screws and barrels of injection molding machines and extruders is a key link to ensure production continuity and product quality. Traditional cleaning methods mainly include liquid cleaning and resin cleaning. Among them, liquid cleaning mostly uses acidic or alkaline liquid cleaning agents (such as sodium dodecylbenzenesulfonate and triethanolamine oleate). Although they can quickly soften residues, there is a potential corrosion hazard to the metal screws and the inner wall of the barrel. Long-term use may cause equipment rust and shorten the service life; Resin cleaning mainly relies on cleaning materials based on polypropylene substrates, which remove residues through mechanical friction and foaming at high temperatures. However, this type of technology has significant defects: the polypropylene resin itself is relatively expensive, and the processing temperature needs to be raised above 220°C during high-temperature cleaning to achieve the separation of melt fluidity and residues, resulting in a significant increase in energy consumption. In addition, the melt viscosity of polypropylene-based cleaning materials is high, and the compounded friction materials have poor dispersion in the melt, resulting in uneven cleaning and easy generation of cleaning dead ends.

[0003] In contrast, linear low-density polyethylene resin has a linear molecular structure, a lower melting temperature, and a smaller melt viscosity, which can effectively fill the cleaning interface and has the advantages of low-temperature energy saving and efficient cleaning applications; for example, Chinese Patent Application No. 201710257198.5 uses linear low-density polyethylene resin as the main material of the cleaning material and uses an AC foaming agent to increase the friction force between the melt and the cleaning interface, thereby endowing the linear low-density polyethylene resin-based cleaning material with good cleaning ability; however, in this technical solution, only friction cleaning is relied on, and in addition, the gas generated by foaming is easy to precipitate, making it difficult to form a stable dynamic friction pressure, resulting in insufficient cleaning efficiency and a high consumption of cleaning materials. Summary of the Invention

[0004] In order to solve the technical problems mentioned in the background art, the purpose of the present invention is to provide a cleaning material for the screw barrel of an injection molding machine and an extruder and a preparation method thereof.

[0005] The purpose of the present invention can be achieved by the following technical solutions:

[0006] A cleaning material for the screw barrel of an injection molding machine and an extruder, the components of which are: 18-22 wt% of friction filler, 4.2-5.5 wt% of foaming cleaning aid, 0.8-1 wt% of internal lubricant, 0.5-0.7 wt% of compatibilizer, 1.2-1.5 wt% of surfactant, 1.5-2 wt% of viscosity reducer, and 0.1-0.13 wt% of antioxidant, and the balance is linear low-density polyethylene resin.

[0007] Among them, the foaming cleaning aid is prepared by the following method:

[0008] Step A1: Mix 3-aminopropyltrimethoxysilane, triethylamine and anhydrous tetrahydrofuran, introduce dry nitrogen for protection, heat up to 30-40 °C, slowly add n-alkyl bromoalkene and stir for reaction for 1.5-2 h, then continue to heat up and reflux for 2-3 h, cool and then filter by suction, and then rotary evaporate to remove tetrahydrofuran to obtain a surface modifier.

[0009] Furthermore, the dosage ratio of 3-aminopropyltrimethoxysilane, n-alkyl bromoalkene, triethylamine and anhydrous tetrahydrofuran is 0.1 mol: 0.2 mol: 25-30 mL: 160-220 mL. The n-alkyl bromoalkene replaces 3-aminopropyltrimethoxysilane to introduce a double-branched alkyl chain-terminated alkenyl structure modification into 3-aminopropyltrimethoxysilane.

[0010] Furthermore, the n-alkyl bromoalkene is one of 5-bromo-1-pentene and 7-bromo-1-heptene. Under the regulation of the alkyl chain length, a moderate chelating force can be formed between the surface organic compound of the foaming cleaning aid and the inner wall of the barrel, maintaining good cleaning ability and being easy to detach from the melt at the same time.

[0011] Step A2: Mix the surface modifier and dioxane, add potassium bicarbonate fine powder and stir to disperse, heat up to 65-75 °C, control the humidity of the reaction system to be 90% RH, stir and react for 8-10 h, cool and then centrifuge, take the precipitate, wash and dry it with acetone to obtain a modified matrix.

[0012] Furthermore, the dosage ratio of potassium bicarbonate fine powder, surface modifier and dioxane is 50 g: 12-18 mmol: 200-300 mL. In a high-humidity reaction system, the potassium bicarbonate fine powder absorbs moisture and is slightly deliquescent on the surface to form a local alkaline region, promoting the hydrolysis coupling of the surface modifier on its surface.

[0013] Furthermore, the fineness of the potassium bicarbonate fine powder is 50-80 mesh. Under this particle size control, it is beneficial to the full loading of the surface modifier and at the same time maintains the good foaming ability of the core potassium bicarbonate.

[0014] Step A3: Mix the modified matrix, photoinitiator and carbon tetrachloride, heat up to 40-50 °C, apply 2 UV irradiation of 600-700 mW / cm, slowly add pentaerythritol tetrakis(mercaptoacetate) and stir for reaction for 3.5-4.5 h, rotary evaporate to remove carbon tetrachloride, and then wash and dry with ethanol to obtain the foaming cleaning aid.

[0015] Further, the dosage ratio of the modified matrix, pentaerythritol tetrakis(mercaptoacetate), photoinitiator, and carbon tetrachloride is 50 g: 7-10 mmol: 15-20 mg: 150-200 mL. Under photoinitiation, pentaerythritol tetrakis(mercaptoacetate) is enriched on the surface of the modified matrix and undergoes addition crosslinking with the vinyl groups introduced on the surface to coat the surface. The formed thioether and tertiary amine form a chelate structure.

[0016] Further, the friction filler is chopped glass fiber, which provides good cleaning ability in combination with the foaming process.

[0017] Further, the viscosity reducer is polyethylene glycol 400, which effectively reduces the melt viscosity of the polyethylene system and facilitates the discharge of the cleaning material.

[0018] A preparation method of a cleaning material for a screw barrel of an injection molding machine and an extruder is as follows: Mix an internal lubricant, a compatibilizer, a surfactant, a viscosity reducer, an antioxidant, and a linear low-density polyethylene resin. The mixed material is fed from the main feeding port of the extruder, and the friction filler is fed from the side feeding port. It is plasticized and extruded at 180-200 °C and pelletized. After the pellets are crushed, they are mixed with a foaming cleaning aid to obtain the cleaning material.

[0019] The beneficial effects of the present invention:

[0020] The cleaning material of the present invention uses linear low-density polyethylene resin as the base material and chopped glass fiber as the friction material, and introduces a foaming cleaning aid to significantly improve the cleaning ability of the cleaning material. It uses potassium bicarbonate as the core material, which is substituted by bromo-n-alkyl alkene and 3-aminopropyltrimethoxysilane, introducing a double-branched terminal alkenyl structure with an alkyl chain, which is the surface modifier. The surface modifier is coupled and loaded on the surface of potassium bicarbonate, and then in-situ polymerized with pentaerythritol tetrakis(mercaptoacetate) on the surface of potassium bicarbonate to coat potassium bicarbonate; compared with traditional cleaning materials, the present invention adopts a micro-foaming cleaning process. Potassium bicarbonate decomposes when heated, and the surface polymerized coating interacts with the matrix to reduce the escape of decomposition gas, generating dynamic pressure in the melt. In cooperation with the glass fiber, a brushing effect is formed during the melt flow process, and the thioether and tertiary amine structures in its surface polymerized coating form a polycyclic chelation effect. On the one hand, the chelation interface is different from the traditional melt infiltration interface, effectively eliminating cleaning dead corners and improving the cleaning depth. On the other hand, it increases the brushing friction between the melt and the inner walls of the screw and the barrel. Through the triple effects of chemical chelation - dynamic foaming - physical scraping, efficient, low-consumption, and deep screw cleaning is achieved, solving the core problems of insufficient cleaning ability, high cost, and high energy consumption in traditional technologies. Specific embodiments

[0021] Next, in combination with the embodiments of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative efforts belong to the scope of protection of the present invention.

[0022] Example 1. Preparation of the cleaning material for the screw barrel of an injection molding machine and an extruder is as follows:

[0023] (1) Preparation of the foaming cleaning aid

[0024] Step A1: Mix 3-aminopropyltrimethoxysilane, triethylamine, and anhydrous tetrahydrofuran, introduce dry nitrogen for protection, heat up to 30°C, slowly add n-alkyl bromoalkene and stir for 2 h, then continue to heat up and reflux for 3 h. Among them, n-alkyl bromoalkene is selected as 5-bromo-1-pentene, and the dosage ratio of 3-aminopropyltrimethoxysilane, 5-bromo-1-pentene, triethylamine, and anhydrous tetrahydrofuran is 0.1 mol: 0.2 mol: 25 mL: 160 mL. After cooling, filter by suction, and then rotary evaporate to remove tetrahydrofuran to obtain the surface modifier.

[0025] Step A2: Mix the surface modifier and dioxane, add potassium bicarbonate fine powder and stir to disperse, heat up to 65°C, control the humidity of the reaction system to 90% RH, and stir for 10 h. Among them, potassium bicarbonate fine powder is 50-mesh fine powder, and the dosage ratio of potassium bicarbonate fine powder, surface modifier, and dioxane is 50 g: 12 mmol: 200 mL. After cooling, centrifuge, take the precipitate, wash it with acetone and dry it to obtain the modified matrix.

[0026] Step A3: Mix the modified matrix, photoinitiator, and carbon tetrachloride, heat up to 40°C, apply ultraviolet irradiation of 600 mW / cm 2 Slowly add pentaerythritol tetrakis(mercaptoacetate) and stir for 4.5 h. Among them, the photoinitiator is selected as photoinitiator 1173, and the dosage ratio of the modified matrix, pentaerythritol tetrakis(mercaptoacetate), photoinitiator 1173, and carbon tetrachloride is 50 g: 7 mmol: 15 mg: 150 mL. Rotary evaporate to remove carbon tetrachloride, and then wash it with ethanol and dry it to obtain the foaming cleaning aid.

[0027] (2) Preparation of the cleaning material

[0028] Ingredients: friction filler 18wt%, selected ECS-11-3.0 type chopped glass fiber; foaming cleaning aid 5.5wt%, homemade by this embodiment; internal lubricant 0.8wt%, selected EP520P type PE wax; compatibilizer 0.5wt%, selected FT-900E type maleic anhydride grafted polyethylene; surfactant 1.5wt%, selected industrial grade diethylene glycol butyl ether; viscosity reducer 1.5wt%, selected industrial grade polyethylene glycol 400; antioxidant 0.1wt%, selected antioxidant 1010; the balance is linear low-density polyethylene resin, selected 7042 type resin raw material.

[0029] Melt mixing: The internal lubricant, compatibilizer, surfactant, viscosity reducer, antioxidant and linear low-density polyethylene resin are mixed in a high-speed mixer at 600 rpm for 10 minutes. The obtained mixture is fed from the main feeding port of the extruder, and the friction filler is fed from the side feeding port. The mixture is plasticized, extruded and pelletized at 180°C. The pellets are crushed and mixed with the foaming cleaning aid to obtain the cleaning material.

[0030] Example 2, preparation of cleaning material for screw barrels of injection molding machines and extruders, as follows:

[0031] (1) Preparation of foaming cleaning aid

[0032] Step A1: 3-aminopropyltrimethoxysilane, triethylamine and anhydrous tetrahydrofuran are mixed, dry nitrogen is introduced for protection, the temperature is raised to 30°C, and n-alkyl bromide is slowly added and stirred for reaction for 1.8 hours, and then the temperature is continued to reflux for 2.5 hours, wherein the n-alkyl bromide is 5-bromo-1-pentene, and the amount ratio of 3-aminopropyltrimethoxysilane, 5-bromo-1-pentene, triethylamine and anhydrous tetrahydrofuran is 0.1 mol: 0.2 mol: 25 mL: 180 mL. After cooling, suction filtration is performed, and tetrahydrofuran is removed by rotary evaporation to obtain a surface modifier.

[0033] Step A2: Mix the surface modifier and dioxane, add potassium bicarbonate powder and stir to disperse, heat to 70°C, control the humidity of the reaction system to 90%RH, and stir to react for 9 hours, wherein the potassium bicarbonate powder is 50 mesh powder, and the amount ratio of potassium bicarbonate powder, surface modifier and dioxane is 50g:15mmol:220mL. After cooling, centrifuge, take the precipitate, wash and dry it with acetone to obtain a modified matrix.

[0034] Step A3: Mix the modified substrate, photoinitiator and carbon tetrachloride, raise the temperature to 40°C, and apply 700 mW / cm 2Under ultraviolet irradiation, slowly add pentaerythritol tetrathioglycolate and stir to react for 4 hours, wherein the photoinitiator is photoinitiator 1173, and the amount ratio of modified matrix, pentaerythritol tetrathioglycolate, photoinitiator 1173 and carbon tetrachloride is 50g:8mmol:15mg:160mL. Rotary evaporation is used to remove carbon tetrachloride, and then the mixture is washed and dried with ethanol to obtain a foaming cleaning agent.

[0035] (2) Preparation of cleaning materials

[0036] Ingredients: friction filler 22wt%, selected ECS-11-3.0 type chopped glass fiber; foaming cleaning aid 4.2wt%, homemade by this embodiment; internal lubricant 1wt%, selected EP520P type PE wax; compatibilizer 0.7wt%, selected FT-900E type maleic anhydride grafted polyethylene; surfactant 1.2wt%, selected industrial grade diethylene glycol butyl ether; viscosity reducer 2wt%, selected industrial grade polyethylene glycol 400; antioxidant 0.13wt%, selected antioxidant 1010; the balance is linear low-density polyethylene resin, selected 7042 type resin raw material.

[0037] Melt mixing: The internal lubricant, compatibilizer, surfactant, viscosity reducer, antioxidant and linear low-density polyethylene resin are mixed in a high-speed mixer at 600 rpm for 10 minutes. The obtained mixture is fed from the main feeding port of the extruder, and the friction filler is fed from the side feeding port. The mixture is plasticized, extruded and pelletized at 200°C. The pellets are crushed and mixed with the foaming cleaning aid to obtain the cleaning material.

[0038] Example 3, preparation of cleaning material for screw barrels of injection molding machines and extruders, as follows:

[0039] (1) Preparation of foaming cleaning aid

[0040] Step A1: 3-aminopropyltrimethoxysilane, triethylamine and anhydrous tetrahydrofuran are mixed, dry nitrogen is introduced for protection, the temperature is raised to 40°C, and n-alkyl bromide is slowly added and stirred for reaction for 1.5 hours, and then the temperature is continued to reflux for 2 hours, wherein the n-alkyl bromide is 7-bromo-1-heptene, and the amount ratio of 3-aminopropyltrimethoxysilane, 7-bromo-1-heptene, triethylamine and anhydrous tetrahydrofuran is 0.1 mol: 0.2 mol: 30 mL: 220 mL. After cooling, suction filtration is performed, and tetrahydrofuran is removed by rotary evaporation to obtain a surface modifier.

[0041] Step A2: Mix the surface modifier and dioxane, add potassium bicarbonate powder and stir to disperse, heat to 75°C, control the humidity of the reaction system to 90% RH, and stir to react for 8 hours, wherein the potassium bicarbonate powder is 80 mesh powder, and the amount ratio of potassium bicarbonate powder, surface modifier and dioxane is 50g:18mmol:300mL. After cooling, centrifuge, take the precipitate, wash and dry it with acetone to obtain a modified matrix.

[0042] Step A3: Mix the modified substrate, photoinitiator and carbon tetrachloride, raise the temperature to 50°C, and apply 700 mW / cm 2 Under ultraviolet irradiation, pentaerythritol tetrathioglycolate was slowly added and stirred for reaction for 3.5 hours, wherein the photoinitiator was photoinitiator 1173, and the amount ratio of modified substrate, pentaerythritol tetrathioglycolate, photoinitiator 1173 and carbon tetrachloride was 50g:10mmol:20mg:200mL, and carbon tetrachloride was removed by rotary evaporation, and then washed and dried with ethanol to obtain a foaming cleaning aid.

[0043] (2) Preparation of cleaning materials

[0044] Ingredients: 20wt% friction filler, selected ECS-11-3.0 type chopped glass fiber; 4.8wt% foaming cleaning aid, homemade by this embodiment; 0.9wt% internal lubricant, selected EP520P type PE wax; 0.7wt% compatibilizer, selected FT-900E type maleic anhydride grafted polyethylene; 1.4wt% surfactant, selected industrial grade diethylene glycol butyl ether; 1.7wt% viscosity reducer, selected industrial grade polyethylene glycol 400; 0.11wt% antioxidant, selected antioxidant 1010; the balance is linear low-density polyethylene resin, selected 7042 type resin raw material.

[0045] Melt mixing: The internal lubricant, compatibilizer, surfactant, viscosity reducer, antioxidant and linear low-density polyethylene resin are mixed in a high-speed mixer at 600 rpm for 10 minutes. The obtained mixture is fed from the main feeding port of the extruder, and the friction filler is fed from the side feeding port. The mixture is plasticized, extruded and pelletized at 190°C. The pellets are crushed and mixed with the foaming cleaning aid to obtain the cleaning material.

[0046] Example 4, preparation of cleaning material for screw barrels of injection molding machines and extruders, as follows:

[0047] (1) Preparation of foaming cleaning aid

[0048] Step A1: 3-aminopropyltrimethoxysilane, triethylamine and anhydrous tetrahydrofuran are mixed, dry nitrogen is introduced for protection, the temperature is raised to 40°C, and n-alkyl bromide is slowly added and stirred for reaction for 1.8 hours, and then the temperature is continued to reflux for 2.2 hours, wherein the n-alkyl bromide is 7-bromo-1-heptene, and the amount ratio of 3-aminopropyltrimethoxysilane, 7-bromo-1-heptene, triethylamine and anhydrous tetrahydrofuran is 0.1 mol: 0.2 mol: 28 mL: 200 mL. After cooling, the mixture is filtered and then the tetrahydrofuran is removed by rotary evaporation to obtain a surface modifier.

[0049] Step A2: Mix the surface modifier and dioxane, add potassium bicarbonate powder and stir to disperse, heat to 70°C, control the humidity of the reaction system to 90%RH, and stir to react for 90h, wherein the potassium bicarbonate powder is 80 mesh powder, and the amount ratio of potassium bicarbonate powder, surface modifier and dioxane is 50g:16mmol:240mL. After cooling, centrifuge, take the precipitate, wash and dry it with acetone to obtain a modified matrix.

[0050] Step A3: Mix the modified substrate, photoinitiator and carbon tetrachloride, raise the temperature to 50°C, and apply 600 mW / cm 2 Under ultraviolet irradiation, pentaerythritol tetrathioglycolate was slowly added and stirred for reaction for 3.8 hours, wherein the photoinitiator was photoinitiator 1173, and the amount ratio of modified substrate, pentaerythritol tetrathioglycolate, photoinitiator 1173 and carbon tetrachloride was 50g:9mmol:20mg:170mL. The carbon tetrachloride was removed by rotary evaporation, and then washed and dried with ethanol to obtain a foaming cleaning aid.

[0051] (2) Preparation of cleaning materials

[0052] Ingredients: friction filler 19wt%, selected ECS-11-3.0 type chopped glass fiber; foaming cleaning aid 5.1wt%, homemade by this embodiment; internal lubricant 0.9wt%, selected EP520P type PE wax; compatibilizer 0.6wt%, selected FT-900E type maleic anhydride grafted polyethylene; surfactant 1.3wt%, selected industrial grade diethylene glycol butyl ether; viscosity reducer 1.8wt%, selected industrial grade polyethylene glycol 400; antioxidant 0.1wt%, selected antioxidant 1010; the balance is linear low-density polyethylene resin, selected 7042 type resin raw material.

[0053] Melt mixing: The internal lubricant, compatibilizer, surfactant, viscosity reducer, antioxidant and linear low-density polyethylene resin are mixed in a high-speed mixer at 600 rpm for 10 minutes. The obtained mixture is fed from the main feeding port of the extruder, and the friction filler is fed from the side feeding port. The mixture is plasticized, extruded and pelletized at 190°C. The pellets are crushed and mixed with the foaming cleaning aid to obtain the cleaning material.

[0054] Comparative Example 1: This comparative example refers to Example 4, replacing the foaming cleaning aid with an equal amount of potassium bicarbonate fine powder, and the rest of the implementation process is exactly the same.

[0055] Comparative Example 2: Commercially available Celpurge NX-E cleaning material was selected.

[0056] Samples were taken from the cleaning materials prepared above for cleaning tests. The object to be cleaned was an extruder with the same maintenance cycle and a screw diameter of 50 mm. The specific cleaning process parameters were set as follows:

[0057] Preheating: Preheat the screw barrel to 180 °C and hold for 5 min to equalize the temperature of the screw barrel.

[0058] Injection: Pre-inject 1 kg of cleaning material, the screw speed is 40 rpm, the melt temperature returns to 180 °C, and keep warm for 3 min.

[0059] High-temperature cleaning: Raise the melt temperature to 200 °C, control the screw speed at 25 rpm, and inject the cleaning material again until no visible impurities are discharged.

[0060] Rinsing: Inject 1 kg of LLDPE resin to rinse and discharge the material at 170 °C.

[0061] Record the amount of cleaning material used, and disassemble the machine to check the cleaning quality of the inner wall of the screw barrel, as shown in Table 1 specifically:

[0062] Table 1

[0063]

[0064] From the cleaning test results in Table 1, it can be seen that the screw barrel of the cleaning material prepared in the example has deep cleaning ability. After cleaning, there are almost no visible impurities on the inner wall. The amount of cleaning material for a 50 mm screw is about 4 kg. Compared with the existing cleaning materials, the cleaning efficiency is moderate.

[0065] In the description of the specification, the description referring to terms such as "one embodiment", "example", "specific example", etc. means that the specific features, structures, materials or characteristics described in connection with that embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic expressions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in a suitable manner in any one or more embodiments or examples.

[0066] The above content is only an example and explanation of the present invention. Those skilled in the art of this technology can make various modifications or supplements to the specific embodiments described or use similar methods to replace them. As long as they do not deviate from the invention or exceed the scope defined by the claims of this patent, they should all fall within the protection scope of the present invention.

Claims

1. A cleaning material for screw barrels of injection molding machines and extruders, characterized in that: The specific components are: friction filler 18-22wt%, foaming cleaning aid 4.2-5.5wt%, internal lubricant 0.8-1wt%, compatibilizer 0.5-0.7wt%, surfactant 1.2-1.5wt%, viscosity reducer 1.5-2wt% and antioxidant 0.1-0.13wt%, and the balance is linear low-density polyethylene resin; The foaming cleaning aid is prepared by the following method: Step A1: 3-aminopropyltrimethoxysilane, triethylamine and anhydrous tetrahydrofuran are mixed, dry nitrogen is introduced for protection, the temperature is raised to 30-40° C., n-alkyl bromide is slowly added, stirred and reacted for 1.5-2 h, and then the temperature is continued to rise and reflux for 2-3 h, and the mixture is filtered after cooling, and tetrahydrofuran is removed by rotary evaporation to obtain a surface modifier; Step A2: Mix the surface modifier and dioxane, add potassium bicarbonate powder, stir and disperse, heat to 65-75°C, control the humidity of the reaction system to 90% RH, stir and react for 8-10 hours, cool and centrifuge, take the precipitate, wash and dry with acetone, and obtain a modified matrix; Step A3: Mix the modified substrate, photoinitiator and carbon tetrachloride, raise the temperature to 40-50°C, and apply 600-700 mW / cm 2 Under ultraviolet irradiation, pentaerythritol tetrathioglycolate was slowly added and stirred for reaction for 3.5-4.5 hours, carbon tetrachloride was removed by rotary evaporation, and then washed with ethanol and dried to obtain a foaming cleaning aid.

2. The cleaning material for the screw barrel of an injection molding machine and an extruder according to claim 1, characterized in that: The usage ratio of 3-aminopropyltrimethoxysilane, brominated n-alkylene, triethylamine and anhydrous tetrahydrofuran is 0.1 mol: 0.2 mol: 25-30 mL: 160-220 mL.

3. The cleaning material for the screw barrel of an injection molding machine and an extruder according to claim 2, characterized in that: The brominated n-alkyl olefin is one of 5-bromo-1-pentene and 7-bromo-1-heptene.

4. The cleaning material for the screw barrel of an injection molding machine and an extruder according to claim 2, characterized in that: The usage ratio of potassium bicarbonate powder, surface modifier and dioxane is 50g:12-18mmol:200-300mL.

5. The cleaning material for the screw barrel of an injection molding machine and an extruder according to claim 4, characterized in that: The fineness of potassium bicarbonate powder is 50-80 mesh.

6. The cleaning material for the screw barrel of an injection molding machine and an extruder according to claim 4, characterized in that: The usage ratio of the modified substrate, pentaerythritol tetrathioglycolate, the photoinitiator and carbon tetrachloride is 50g:7-10mmol:15-20mg:150-200mL.

7. The cleaning material for the screw barrel of an injection molding machine and an extruder according to claim 1, characterized in that: The friction filler is chopped glass fiber.

8. The cleaning material for the screw barrel of an injection molding machine and an extruder according to claim 1, characterized in that: The viscosity reducing agent is polyethylene glycol 400.

9. A method for preparing a cleaning material for a screw barrel of an injection molding machine and an extruder according to any one of claims 1 to 8, characterized in that: Specifically, internal lubricant, compatibilizer, surfactant, viscosity reducer, antioxidant and linear low-density polyethylene resin are mixed, the mixture is fed from the main feeding port of the extruder, and the friction filler is fed from the side feeding port, plasticized, extruded and pelletized at 180-200°C, and the pellets are crushed and mixed with the foaming cleaning aid to obtain the cleaning material.

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