Preparation method and process equipment of high-concentration color preform

Abstract

The application relates to the color master batch manufacturing field and discloses a preparation method and process equipment of high-concentration color pre-materials. The manufacturing process comprises the following steps: S1, accurately weighing temperature-sensitive pigments and resins; S2, continuously mixing under controllable temperature; S3, further melting, grinding, shearing and cooling extrusion crushing; and S4, screening to obtain high-concentration color pre-materials. The application can effectively protect the pigments from the risk of denaturation caused by high temperature in the pre-material preparation process, rapidly cool down through the effective linkage under the controllable temperature of multiple process sections, shorten the time of the pigments in high temperature, and further avoid the problems of poor dispersibility of the pigments, color fluctuation, appearance of mixed colors and unstable product quality of the temperature-sensitive pigments in the manufacturing process of the high-concentration color pre-materials. The equipment linkage is good, the labor intensity of workers is reduced, and continuous production can be realized.

Description

Technical Field

[0001] This invention relates to the field of color masterbatch manufacturing, specifically to a method and equipment for preparing high-concentration colored preforms. Background Technology

[0002] Masterbatch manufacturing is an intermediate step in the plastics production industry. Traditionally, pigments are dispersed into a carrier as color particles through grinding or twin-screw extrusion in a specific ratio. This method offers excellent coloring effects, allows for precise weighing, and produces no dust, making it widely used for coloring plastic products across various industries. Currently, the market demand for high-concentration masterbatches is increasing; however, the higher the pigment concentration, the worse the pigment dispersion in the masterbatch, and the more pronounced problems such as color fluctuations, discoloration, and unstable product quality become during production. Compared to large multinational corporations abroad, my country's high-concentration masterbatch production technology and processes are relatively backward.

[0003] Traditionally, in the preparation of color masterbatches, low-molecular-weight wax is used to wet and coat the pigments, followed by shearing and kneading using a rotor in a mixer, then breaking up the pigment agglomerates using a three-roll mill, and finally diluting and granulating using a twin-screw extruder. However, practical production has revealed the following shortcomings in current color masterbatch manufacturing: (a) In traditional color masterbatch manufacturing processes, the mixing process often results in excessively high internal temperatures due to frictional heat generation, leading to the burning of small-molecule dispersants. This results in poor pigment wetting and further increases the difficulty of subsequent dispersion processes. Furthermore, small-molecule dispersants may precipitate from the final colored product. (b) Current common color masterbatch manufacturing processes are long and complex, with poor coordination between different machines, a large number of operators, low production efficiency, and limited capacity. In summary, these problems are prevalent in my country's color masterbatch manufacturing processes, resulting in my country's color masterbatch manufacturing technology being significantly lower than that of foreign monopolistic enterprises, severely restricting the development prospects of high-end color masterbatch manufacturing.

[0004] Therefore, it is necessary to invent a high-concentration preform manufacturing process to solve the above problems. Summary of the Invention

[0005] The purpose of this invention is to provide a method and equipment for preparing high-concentration colored preforms, solving the problems of easy precipitation of small-molecule additives and low production efficiency in existing color masterbatches. It mainly includes a feeder with controllable nozzle diameter; a continuous mixing extruder with multiple rotation modes and controllable cavity temperature; a five-roll mill that simultaneously performs melt grinding, shearing, cooling, extrusion, and crushing; and a multi-layer vibrating screen. The manufacturing process includes the following steps: S1, accurately weighing temperature-sensitive pigments and resins; S2, continuous mixing under controllable temperature; S3, further melting, grinding, shearing, cooling, and extrusion crushing; S4, sieving to obtain high-concentration colored preforms. This invention effectively protects the pigments from the risk of high-temperature denaturation during preform preparation. Through effective linkage of multiple stages under controllable temperature, rapid cooling shortens the time the pigments are at high temperatures, thus avoiding problems such as poor pigment dispersibility, color fluctuations, discoloration, and unstable product quality in the manufacture of high-concentration colored preforms. The equipment in this invention has good linkage and coordination, reducing the labor intensity of workers and enabling continuous production.

[0006] To solve the above-mentioned technical problems, the present invention adopts the following technical solution: A method for preparing a high-concentration colored preform includes the following steps: S1. Accurately weigh the raw materials, including pigments and resins, mix them evenly, and then feed them. S2. Control the feeding amount and mix the materials. Control the temperature during the mixing and plasticizing process until the materials are fully plasticized and then discharged. S3, then enters the five-roll mill for melting, grinding, shearing, cooling, extrusion, and crushing before being output; S4. Filter the crushed material to obtain the high-concentration colored preform.

[0007] Preferably, the steps include: S1. Accurately weigh the raw materials, including pigments and low-density polyethylene resin, mix them evenly, and then add them to the feeder; S2. The feeding amount is controlled by adjusting the feed port diameter. The material enters the mixing chamber from the feeder through the feed port. The mixed material enters the continuous mixer and is sheared and plasticized by the rotor in the mixing chamber. During the plasticizing process, the temperature in the mixing chamber can be controlled by adjusting the cooling water temperature or the flow rate of the cooling water pipe until the material is completely plasticized and then discharged. S3. The mixed material is output from the discharge port and fed into the five-roll mill with preset roller temperatures. After melting, grinding, shearing, cooling, extrusion and crushing, the material is output. S4. The multi-layer vibrating screen filters the material output from step S3 through a vibrating screen to obtain the high-concentration colored pre-made material.

[0008] Preferably, the mass ratio of the pigment to the low-density polyethylene resin is 1:0.6~1.5.

[0009] An apparatus for preparing high-concentration colored preforms as described above is characterized in that it comprises a continuous mixing extruder, a five-roll mill, and a multi-layer vibrating screen; the continuous mixing extruder is disposed above the five-roll mill, and the multi-layer vibrating screen is disposed below the five-roll mill; the five-roll mill comprises a low-speed roller, a medium-speed roller, a high-speed roller, a shovel, a cooling low-speed roller, and a cooling high-speed roller; the low-speed roller, medium-speed roller, and high-speed roller are connected in sequence and disposed above the sequentially connected cooling low-speed roller and cooling high-speed roller, and the high-speed roller is connected to the cooling low-speed roller through the shovel.

[0010] Preferably, the low-speed roller and the medium-speed roller are connected in an opposite, non-uniform, meshing rotational manner; the medium-speed roller and the high-speed roller are connected in an opposite, non-uniform, meshing rotational manner; the speed ratio of the low-speed roller, the medium-speed roller and the high-speed roller is 1:2~4:4~16; the speed ratio of the cooling low-speed roller to the cooling high-speed roller is 1:1.2~1.5.

[0011] The pressure and gap between the low-speed and medium-speed rollers are adjustable, while the speed ratio between the two rollers is fixed and cannot be changed. Similarly, the pressure and gap between the medium-speed and high-speed rollers are adjustable, as are their speed ratios. The material is ground using differential speed and gap between the low-speed and medium-speed rollers, between the medium-speed and high-speed rollers, and between the cooling low-speed and cooling high-speed rollers, thus distributing and dispersing pigment agglomerates.

[0012] Preferably, the rotational speed of the low-speed roller is 10~30 r / min; the rotational speed of the medium-speed roller is 20~120 r / min; the rotational speed of the high-speed roller is 40~480 r / min; the temperature of the low-speed roller, the medium-speed roller, and the high-speed roller is 80~160℃; the rotational speed of the cooling low-speed roller is 20~30 r / min; the rotational speed of the cooling high-speed roller is 22~45 r / min; the temperature of the cooling low-speed roller and the cooling high-speed roller is 10~20℃; and the outer surfaces of the cooling low-speed roller and the cooling high-speed roller are provided with protrusions.

[0013] The low-speed and high-speed cooling rollers are cooled by an external compressor chiller. Their uneven surfaces increase the material contact area, achieving rapid cooling and preventing frictional heat generation during the process, thus raising the operating temperature to 10-20℃. Furthermore, the raised surfaces of the low-speed and high-speed cooling rollers, combined with their differential speed, further enhance the effective crushing and dispersion of the material.

[0014] Preferably, one end of the shovel is in contact with the high-speed roller at a tangential position; the other end of the shovel is connected to the low-speed cooling roller; the shovel is positioned at an angle of 15 to 30 degrees with the radius and center line of the low-speed cooling roller.

[0015] Preferably, the continuous mixing extruder is equipped with a feeder, a feed port, an exhaust port, a discharge port, a cooling water pipe, and a rotor; the discharge port is connected to the low-speed roller; the location of the discharge port forms an angle of 15 to 30° with the radius and center line of the low-speed roller.

[0016] Preferably, the multi-layer screen vibrating screen is connected to the cooling high-speed roller; the position of the multi-layer screen vibrating screen forms an angle of 15~30° with the radius and center line of the cooling high-speed roller.

[0017] Preferably, the surface temperature of the low-speed roller, the medium-speed roller, and the high-speed roller is controlled by an external high-pressure steam water temperature controller; the cooling low-speed roller and the cooling high-speed roller are cooled by an external compressor chiller; a weighing scale is installed on the feeder; the discharge port is connected to a motor to control the diameter; the rotor is a dual rotor, and its rotation mode is opposite, equal speed, and meshing; the cooling water pipe is connected to a compressor chiller to control the temperature inside the rotor cavity; the multi-layer screen vibrating screen is divided into upper and lower screens, with the upper screen having a 3mm aperture and the lower screen having a 1mm aperture.

[0018] The feeder is equipped with a dedicated weighing scale, which can adjust the feeding speed and measure the weight. The discharge port is equipped with a dedicated motor to control the diameter.

[0019] Compared with the prior art, implementing the present invention has the following beneficial effects: (1) The present invention can realize the pre-wetting of pigments without the addition of small molecule dispersants, and avoid pigment discoloration at high temperature by effectively controlling the temperature inside the continuous mixing extruder cavity; (2) The present invention utilizes the control of the discharge port diameter to control the feeding amount and adjust the melting pressure inside the cylinder to change the degree of material extrusion; in addition, the five-roll mill is connected to an external high-pressure steam water temperature controller to control the temperature, the state of melting but not melting and control the viscosity of the melt in the molten state, and utilizes the synergistic effect of adjusting the five-roll spacing, temperature and pressure to achieve effective grinding effect, and complete the distribution and dispersion of pigment agglomerates. (3) This invention can effectively protect pigments from the risk of denaturation due to high temperature during the preform preparation process. By effectively linking multiple stages under controllable temperature, it rapidly cools and reduces the time pigments are at high temperatures, thereby avoiding problems such as poor pigment dispersibility, color fluctuations, discoloration, and unstable product quality in the manufacture of high-concentration colored preforms. This invention combines a continuous mixing extruder, a five-roll mill, and related auxiliary equipment in a systematic manner. The various parts of the production process work closely together, enabling continuous production with low labor intensity and high production efficiency. Attached Figure Description

[0020] Figure 1 This is a structural diagram of the device of the present invention.

[0021] Figure 2 This is a schematic diagram of the surfaces of the low-speed cooling roller and the high-speed cooling roller of the device of the present invention. Detailed Implementation

[0022] To make the objectives, technical solutions, and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings.

[0023] Example 1 like Figure 1 As shown, an apparatus for manufacturing a high-concentration colored preform material is provided. The apparatus includes: a feeder 1, a feed inlet 2, an exhaust outlet 3, a discharge outlet 4, a cooling water pipe 5, a rotor 6, a five-roll mill 7, and a multi-layer vibrating screen 14. The feeder 1, feed inlet 2, exhaust outlet 3, discharge outlet 4, cooling water pipe 5, and rotor 6 constitute a continuous mixing extruder 15. The five-roll mill 7 consists of a low-speed roller 8, a medium-speed roller 9, a high-speed roller 10, a scraper 11, a cooling low-speed roller 12, and a cooling high-speed roller 13. The continuous mixing extruder 15 is located above the five-roll mill 7, and the discharge outlet 4 is connected to the low-speed roller 8 at an angle θ (15-30°) between the radius of the low-speed roller 8 and the center line. The multi-layer vibrating screen 14 is located below the cooling low-speed roller 12, and its connection point is at an angle θ (15-30°) between the radius of the cooling high-speed roller 13 and the center line.

[0024] The feeder 1 is equipped with a special weighing scale, which can adjust the feeding speed and measure the weight.

[0025] The discharge port 4 is equipped with a dedicated connecting motor to control the diameter.

[0026] The rotor 6 rotates in opposite directions, at the same speed, and meshing, and the temperature inside the rotor cavity can be controlled by connecting it to a compressor chiller via the cooling water pipe.

[0027] The surface temperature of the three high-temperature rollers, namely low-speed roller 8, medium-speed roller 9, and high-speed roller 10, is controlled by an external high-pressure steam water temperature controller, and the temperature is controlled at 80~160℃. The rotation mode of low-speed roller 8 and medium-speed roller 9 is opposite, non-uniform speed, and meshing. The pressure and gap between the two rollers are adjustable, and the speed ratio between the two rollers is fixed and cannot be changed. The rotation mode of medium-speed roller 9 and high-speed roller 10 is opposite, non-uniform speed, and meshing. The pressure and gap between the two rollers are adjustable, and the speed ratio between the two rollers is adjustable. In the five-roller machine 7, the speed ratio of low-speed roller 8: medium-speed roller 9: high-speed roller 10 is 1:(2~4):(4~16), wherein the speed of low-speed roller 8 is 10~30r / min, the speed of medium-speed roller 9 is 20~120r / min, and the speed of high-speed roller 10 is 40~480r / min.

[0028] The scraper 11 of the five-roll mill 7 contacts the high-speed roller 10 tangentially; the other end of the scraper is positioned above the gap of the low-speed cooling roller 12, with the connection point at an angle θ between the radius of the high-speed cooling roller 12 and the center line, where θ = 15~30°; the speed ratio of the low-speed cooling roller 12 to the high-speed cooling roller 13 is 1:(1.2~1.5); the speed of the low-speed cooling roller 12 is 20~30 r / min, and the speed of the high-speed cooling roller 13 is 22~45 r / min; the low-speed cooling roller 12 and the high-speed cooling roller 13 are cooled by an external compressor chiller, such as... Figure 2 As shown, its surface is uneven to increase the contact area of ​​the material, so as to achieve rapid cooling of the material and avoid frictional heat generation during the process, thereby increasing the working temperature. The temperature is controlled at 10~20℃.

[0029] The multi-layer vibrating screen 14 is divided into upper and lower screens. The upper screen has a mesh size of 3mm, and the lower screen has a mesh size of 1mm.

[0030] Example 2 This embodiment proposes a manufacturing process for high-concentration colored preforms, including the following steps: S1. Accurately weigh 50 parts of red pigment (CIPR48:2) and 50 parts of linear low-density polyethylene, mix them evenly, and then add them to the feeder. S2. The feeding amount is controlled by adjusting the feed port diameter. The material enters the mixing chamber from the feeder through the feed port. The temperature is set to 120~160℃ and the speed is set to 280rpm. The mixed material enters the continuous mixer and is sheared and plasticized by the rotor in the mixing chamber. During the plasticization process, the temperature in the mixing chamber can be controlled by adjusting the cooling water temperature or the flow rate of the cooling water pipe until the material is completely plasticized and then discharged. S3. The mixed material is output from the discharge port and fed into a five-roll mill with a preset temperature. The temperatures of the high-temperature low-speed roller, high-temperature medium-speed roller, and high-temperature high-speed roller are set to 105~135℃. The speed ratio of the high-temperature low-speed roller, high-temperature medium-speed roller, and high-temperature high-speed roller is 1:3:9, and the speeds are 10r / min, 30r / min, and 90r / min, respectively. The material is then ground and output to the cooling low-speed roller and cooling high-speed roller. The temperature of the cooling low-speed roller and cooling high-speed roller is set to 12℃. The speed ratio of the cooling low-speed roller and cooling high-speed roller is 1:1.3, and the speeds are 20r / min and 26r / min, respectively. S4. The multi-layer vibrating screen filters the material output from step S3 through a vibrating screen to obtain high-concentration colored pre-made material.

[0031] Comparative Example 1 Accurately weigh 50 parts of red pigment (CIPR48:2) and 50 parts of linear low-density polyethylene. Mix them and add them to an internal mixer. Set the mixer temperature to 130℃ and the mixing time to 20 minutes. After the material melts, discharge it to a three-roll mill. Set the temperature of the three-roll mill to 130~150℃, the speed ratio of the three rollers to be 1:3:9, and the speeds to be 10 r / min, 30 r / min, and 90 r / min, respectively. After grinding the material six times, cool it and pulverize it after 20 minutes to obtain a comparative sample.

[0032] Example of effect 1 The characterization of tinting strength shall be performed in accordance with GB / T 5211.19-1988, "Determination of Relative Tinting Strength and Diluted Color of Coloring Pigments - Visual Comparison Method," which specifies the formula for calculating tinting strength: (1) In the above formula, S is the coloring intensity (%); A is the ratio of the mass of the comparative sample to the mass of the resin; B is the ratio of the mass of the example sample to the mass of the resin.

[0033] The calculation result is S=105%. The data shows that the coloring effect of Example 2 is 5% higher than that of Comparative Example 1, indicating that Example 2 protects the pigment better than Comparative Example 1 and is not lost due to high temperature processing.

[0034] Example 3 This embodiment proposes a manufacturing process for high-concentration colored preforms, including the following steps: S1. Accurately weigh 40 parts of blue pigment (CIPB15:3) and 60 parts of low-density polyethylene, mix them evenly, and then add them to the feeder. S2. The feeding amount is controlled by adjusting the feed port diameter. The material enters the mixing chamber from the feeder through the feed port. The temperature is set to 140~150℃ and the speed is set to 400rpm. The mixed material enters the continuous mixer and is sheared and plasticized by the rotor in the mixing chamber. During the plasticization process, the temperature in the mixing chamber can be controlled by adjusting the cooling water temperature or the flow rate of the cooling water pipe until the material is completely plasticized and then discharged. S3. The mixed material is output from the discharge port and fed into a five-roll mill with a preset temperature. The temperatures of the high-temperature low-speed roller, high-temperature medium-speed roller, and high-temperature high-speed roller are set to 115~125℃, and the speed ratio of the high-temperature low-speed roller, high-temperature medium-speed roller, and high-temperature high-speed roller is 1:2:4, with speeds of 20r / min, 40r / min, and 80r / min respectively. The material is then ground and output to the cooling low-speed roller and cooling high-speed roller. The temperature of the cooling low-speed roller and cooling high-speed roller is set to 15℃, and the speed ratio of the cooling low-speed roller and cooling high-speed roller is 1:1.3, with speeds of 20r / min and 26r / min respectively. S4. The multi-layer vibrating screen filters the material output from step S3 through a vibrating screen to obtain high-concentration colored pre-made material.

[0035] Comparative Example 2 Accurately weigh 40 parts of blue pigment (CIPB15:3) and 60 parts of low-density polyethylene, mix them, and add them to a mixer. Set the mixer temperature to 130℃ and the mixing time to 20 minutes. After the material melts, discharge it into an extruder for granulation. Set the extruder temperature to 140-160℃.

[0036] Example 2 Dispersibility characterization, in accordance with: HG / T 4768.5-2014 "Evaluation of dispersibility in pigments and extender pigments in plastics - Part 5: Determination of colorant dispersibility by heated melt extruder method".

[0037] The measured filtration pressure difference ΔP of the sample in Example 3 was 1.71 Pa, and the FPV was 0.02 Pa / g; the filtration pressure difference ΔP of the sample in Comparative Example 2 was 2.57 Pa, and the FPV was 0.51 Pa / g. The data show that, under the same formulation, the process proposed in this invention results in excellent pigment dispersion performance, low pressure when the sample passes through the extruder, and virtually no aggregation of pigment particles in the resin system.

[0038] Example 4 This embodiment proposes a manufacturing process for high-concentration colored preforms, including the following steps: S1. Accurately weigh 50 parts of green pigment: CIPG7 and 50 parts of linear low-density polyethylene (melt index: 20g / 10min, test method ATSM D1238), mix them evenly and add them to the feeder; S2. The feeding amount is controlled by adjusting the feed port diameter. The material enters the mixing chamber from the feeder through the feed port. The temperature is set to 140~150℃ and the speed is set to 400rpm. The mixed material enters the continuous mixer and is sheared and plasticized by the rotor in the mixing chamber. During the plasticization process, the temperature in the mixing chamber can be controlled by adjusting the cooling water temperature or the flow rate of the cooling water pipe until the material is completely plasticized and then discharged. S3. The mixed material is output from the discharge port and fed into a five-roll mill with a preset temperature. The temperatures of the high-temperature low-speed roller, high-temperature medium-speed roller, and high-temperature high-speed roller are set to 115~125℃, and the speed ratio of the high-temperature low-speed roller, high-temperature medium-speed roller, and high-temperature high-speed roller is 1:2:4, with speeds of 20r / min, 40r / min, and 80r / min respectively. The material is then ground and output to the cooling low-speed roller and cooling high-speed roller. The temperature of the cooling low-speed roller and cooling high-speed roller is set to 15℃, and the speed ratio of the cooling low-speed roller and cooling high-speed roller is 1:1.3, with speeds of 20r / min and 26r / min respectively. S4. The multi-layer vibrating screen filters the material output from step S3 through a vibrating screen to obtain high-concentration colored pre-made material.

[0039] Comparative Example 3 This comparative example uses a commonly used preparation process for color masterbatches, specifically: 750 parts of green color powder (CIPG), 35 parts of linear low-density polyethylene (melt index: 20 g / 10 min, test method ATSM D1238), 14 parts of dispersant (PEWAX), and 1 part of zinc stearate are accurately weighed and added to an internal mixer. The mixer is set to 135℃ and the mixing time is 20 min. After the material is melted, it is discharged into an extruder for granulation. The extruder temperature is set to 140-160℃.

[0040] Example 3 The samples prepared in Example 4 and Comparative Example 3 were measured according to the following methods to determine the corresponding indicators (the results are shown in Table 1): (1) Dispersibility characterization, performed according to: HG / T 4768.5-2014 "Evaluation of dispersibility in pigments and extender pigments in plastics Part 5: Determination of colorant dispersibility by heated melt extrusion method"; (2) Characterization of tinting strength, performed according to GB / T 5211.19-1988 "Determination of relative tinting strength and diluted color of coloring pigments by visual comparison"; (3) Melt index characterization, in accordance with GB / T3682-2000 "Melt mass flow rate and melt volume flow rate of thermoplastics".

[0041] Table 1 Test Data

[0042] As can be seen from Table 1, the filtration pressure difference and filtration value of the sample prepared in Example 4 and the sample prepared in Comparative Example 3 are not significantly different. However, practical application has shown that the formulation of Comparative Example 3 contains 14 parts of PEWAX and 1 part of zinc stearate. When used for coloring downstream products, it is more expensive than that of Example 4 and has a negative impact on the physical properties of the final product during processing.

[0043] The results of Examples 1-3 show that the products prepared using the process of this invention have many advantages over existing products, such as stronger high-temperature resistance, more stable color, stronger dispersion performance, less tendency to agglomerate, lower cost, and better processing performance, achieving significant progress.

[0044] The above-disclosed embodiments are merely preferred embodiments of the present invention and should not be construed as limiting the scope of the present invention. Therefore, any equivalent variations made in accordance with the claims of the present invention are still within the scope of the present invention.

Claims

1. A method for preparing a high-concentration colored preform, characterized in that, Includes the following steps: S1. Accurately weigh the raw materials, including pigments and resins, mix them evenly, and then feed them. S2. Control the feeding amount and mix the materials. Control the temperature during the mixing and plasticizing process until the materials are fully plasticized and then discharged. S3. The roller then enters a five-roll mill for melting, grinding, shearing, cooling, extrusion, and crushing before being output. The five-roll mill includes a low-speed roller, a medium-speed roller, a high-speed roller, a shovel, a cooling low-speed roller, and a cooling high-speed roller. The low-speed roller, medium-speed roller, and high-speed roller are connected in sequence and positioned above the sequentially connected cooling low-speed roller and cooling high-speed roller. The high-speed roller is connected to the cooling low-speed roller via the shovel. The low-speed roller and the medium-speed roller are connected in opposite directions, at non-uniform speeds, and in a meshing manner. The speed ratio of the low-speed roller, the medium-speed roller, and the high-speed roller is 1:2 to 4:4 to 16. The speed ratio of the cooling low-speed roller to the cooling high-speed roller is 1:1.2 to 1.

5. S4. Filter the crushed material to obtain the high-concentration colored preform.

2. The method for preparing high-concentration colored preform as described in claim 1, characterized in that, Includes the following steps: S1. Accurately weigh the raw materials, including pigments and low-density polyethylene resin, mix them evenly, and then add them to the feeder; S2. The feeding amount is controlled by adjusting the diameter of the feeding port. The material enters the mixing chamber from the feeder through the feeding port. The mixed material enters the continuous mixer and is sheared and plasticized by the rotor in the mixing chamber. During the plasticization process, the temperature in the mixing chamber is controlled by adjusting the water temperature of the cooling water or the flow rate of the cooling water pipe until the material is completely plasticized and then discharged. S3. The mixed material is output from the discharge port and fed into the five-roll mill with preset roller temperatures. After melting, grinding, shearing, cooling, extrusion and crushing, the material is output. S4. The multi-layer vibrating screen filters the material output from step S3 through a vibrating screen to obtain the high-concentration colored pre-made material.

3. The method for preparing high-concentration colored preform as described in claim 2, characterized in that, The mass ratio of the pigment to the low-density polyethylene resin is 1:0.6~1.

5.

4. An apparatus for operating the preparation method of high-concentration colored preform as described in claim 1, characterized in that, The system includes a continuous mixing extruder, a five-roll mill, and a multi-layer vibrating screen. The continuous mixing extruder is positioned above the five-roll mill, and the multi-layer vibrating screen is positioned below the five-roll mill. The five-roll mill includes a low-speed roll, a medium-speed roll, a high-speed roll, a shovel, a cooling low-speed roll, and a cooling high-speed roll. The low-speed roll, medium-speed roll, and high-speed roll are connected in sequence and positioned above the sequentially connected cooling low-speed roll and cooling high-speed roll. The high-speed roll is connected to the cooling low-speed roll via the shovel.

5. The device as described in claim 4, characterized in that, The low-speed roller and the medium-speed roller are connected in an opposite, non-uniform, meshing rotational manner; the medium-speed roller and the high-speed roller are connected in an opposite, non-uniform, meshing rotational manner; the speed ratio of the low-speed roller, the medium-speed roller and the high-speed roller is 1:2~4:4~16; the speed ratio of the cooling low-speed roller to the cooling high-speed roller is 1:1.2~1.

5.

6. The device as described in claim 4, characterized in that, The low-speed roller has a rotational speed of 10~30 r / min; the medium-speed roller has a rotational speed of 20~120 r / min; the high-speed roller has a rotational speed of 40~480 r / min; the temperature of the low-speed roller, the medium-speed roller, and the high-speed roller is 80~160℃; the cooling low-speed roller has a rotational speed of 20~30 r / min; the cooling high-speed roller has a rotational speed of 22~45 r / min; the temperature of the cooling low-speed roller and the cooling high-speed roller is 10~20℃; and the outer surfaces of the cooling low-speed roller and the cooling high-speed roller are provided with protrusions.

7. The device as described in claim 4, characterized in that, One end of the shovel is in contact with the high-speed roller at a tangential position; the other end of the shovel is connected to the low-speed cooling roller.

8. The device as described in claim 4, characterized in that, The multi-layer vibrating screen is connected to the high-speed cooling roller.

9. The device as described in claim 4, characterized in that, The continuous mixing extruder is equipped with a feeder, a feed port, an exhaust port, a discharge port, a cooling water pipe, and a rotor; the discharge port is connected to the low-speed roller.

10. The device as described in claim 9, characterized in that, The surface temperature of the low-speed roller, the medium-speed roller, and the high-speed roller is controlled by an external high-pressure steam water temperature controller; the cooling low-speed roller and the cooling high-speed roller are cooled by an external compressor chiller; a weighing scale is installed on the feeder; the discharge port is connected to a motor to control the diameter; the rotor is a dual rotor, and its rotation mode is opposite, equal speed, and meshing; the cooling water pipe is connected to a compressor chiller to control the temperature inside the rotor cavity; the multi-layer screen vibrating screen is divided into upper and lower screens, with the upper screen having a 3mm aperture and the lower screen having a 1mm aperture.

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