Integrated production process for environment-friendly plastic particles

Abstract

The invention discloses an environment-friendly plastic particle integrated production process, and relates to the technical field of plastic production, and the environment-friendly plastic particle integrated production process comprises the steps of raw material preparation and pretreatment, melt extrusion, cooling shaping, pelletizing, screening, quality detection and waste treatment. Compared with the prior art, the method has the advantages that the PCM container is introduced in the cooling and shaping step of the environment-friendly plastic particle integrated production process, and the mounting mode of the PCM container in the water tank, the type selection of the PCM and the composition of a temperature control system are designed in detail, so that the water temperature in the water tank is accurately controlled, the water temperature is maintained within the range of 20-40 DEG C, and the production efficiency of the environment-friendly plastic particle integrated production process is improved. The stability and quality of the plastic sheet in the cooling process are ensured, effective utilization of energy is achieved through the phase change process of PCM, energy consumption is reduced, in addition, a calculation formula of cooling time is designed, resource waste caused by excessive cooling of the plastic sheet is avoided, and production efficiency is improved.

Description

Technical Field

[0001] The invention relates to the technical field of plastic production, and in particular to an integrated production process for environmentally friendly plastic particles. Background Art

[0002] Plastic granules are semi-finished products of the processing industry, which are made by processing polymer resins and other raw materials with various additives and auxiliaries through the granulation process. They are also the raw materials for extrusion, injection molding, blow molding, foaming and other molding processes. In daily life, plastic granules can be used to make various plastic bags, buckets, basins, toys, furniture, stationery and other daily necessities and various plastic products;

[0003] With the rapid development of the plastics industry, plastic products have been widely used in daily life and industrial production. However, the problem of plastic waste disposal has become increasingly prominent and has become an important factor affecting environmental sustainable development. Cooling and shaping is an important part of the waste plastic recycling process that cannot be ignored. In traditional processes, the cooling method is single and it is difficult to achieve precise control of water temperature, which makes it difficult to ensure the stability and quality of plastic sheets during the cooling process. At the same time, the cooling time is also a fixed time, which often leads to waste of resources or over-cooling of products. For this reason, we propose an environmentally friendly integrated production process for plastic particles. Summary of the invention

[0004] The purpose of the present invention is to provide an environmentally friendly integrated production process for plastic particles.

[0005] In order to solve the problems raised in the above background technology, the present invention provides the following technical solutions: an environmentally friendly integrated production process of plastic particles, comprising the following steps:

[0006] Step 1: Raw material preparation and pretreatment: collecting waste plastics, cleaning the waste plastics, removing impurities therein, crushing the cleaned waste plastics into a particle size suitable for extrusion, and adding corresponding reagents to enhance the performance of the crushed plastic particles;

[0007] Step 2: melt extrusion: preheat the extruder, add the crushed waste plastic particles into the hopper of the extruder, and melt the plastic particles and extrude them into sheets through a die;

[0008] Step 3: Cooling and shaping: placing the extruded plastic sheet in a water tank for preliminary cooling, and then using air cooling to further reduce the temperature of the plastic particles;

[0009] Step 4: pelletizing: the cooled and shaped plastic sheet is pulled through a pulling device, and a pelletizer is used to cut the pulled plastic sheet into plastic pellets of a desired length;

[0010] Step 5: Screening: Screen the plastic particles after pelletizing to remove unqualified particles and impurities;

[0011] Step 6: Quality inspection: conduct appearance inspection and performance inspection on the screened plastic particles;

[0012] Step seven: waste treatment: treat the waste gas, waste water and waste residue generated during the production process.

[0013] As a further scheme of the present invention: in the step 1, the waste plastics are obtained from a community waste plastic recycling point, and the specific method of cleaning the waste plastics is to place the collected waste plastics in a cleaning sink, add a bio-enzyme cleaning agent and clean water in a ratio of 1:100, stir for 3min-5min and then soak for 1h, and the specific method of crushing is to use a plastic crusher to crush the waste plastics into plastic particles with a particle size of 5mm, and the corresponding reagents are DOP plasticizer, calcium zinc stabilizer and calcium carbonate filler.

[0014] As a further scheme of the present invention: In the step 2, the specific method of melt extrusion is to preheat the temperature of the extruder to 150°C, and evenly feed the waste plastic particles that have been pretreated and meet the particle size requirements into the hopper of the extruder through an automatic plastic particle feeder, extrude them into continuous sheet forms through the extrusion holes of the mold, and cut them into sheets with a thickness of 4.8mm-5.2mm, a width of 4.8mm-5.2cm, and a length of 2m through a cutting machine.

[0015] As a further solution of the present invention: In the step three, the specific method of cooling and shaping is to place the cut plastic sheet into a water tank with a length of 2.2m-2.5m, a width of 5.2cm-5.5cm, and a depth of 1m. A PCM container is provided in the water tank, and the container is filled with waxy PCM, which is used to control the water temperature in the water tank between 20℃-40℃ through the phase change process of PCM. The PCM container is tightly installed inside the water tank, and a temperature control system is provided in the water tank. The system includes a temperature sensor, a controller and an actuator. The temperature sensor is used to monitor the water temperature in the water tank in real time and transmit the data to the controller. The controller calculates the required PCM phase variable according to the preset water temperature range and the current water temperature data, and adjusts the temperature of the PCM through the actuator. After the plastic sheet is placed in the water tank and initially cooled for 10 minutes, it is moved into the industrial fan cooling area for further cooling according to the current temperature of the plastic sheet. The calculation formula for the cooling time is as follows:

[0016]

[0017] Among them, t represents the time that the industrial fan needs to continue cooling, t1 is the current temperature of the plastic sheet, t0 is the expected temperature of the plastic sheet, and k is the cooling rate coefficient, which is the average value of the temperature drop of the plastic sheet per minute.

[0018] As a further solution of the present invention: in the step four, the traction device includes rollers and a transmission belt, the rollers are used to clamp the cooled and shaped plastic sheets and apply traction, the transmission belts are used to transport the plastic sheets between the rollers to the pelletizer, and after the plastic sheets are transported to the pelletizer, the pelletizer will cut the plastic sheets into particles with a diameter of 5 cm according to preset parameters.

[0019] As a further solution of the present invention: in the step five, the specific method of screening is to place the cut plastic particles into a vibrating screen, set the vibration frequency of the vibrating screen to 15Hz-25Hz, the aperture of the first layer of screen is 5cm-5.2cm, and the aperture of the second layer of screen is 4.8cm-5cm. For plastic particles that are too large or too small, they are crushed and cut again, and for particles with impurities, they are cleaned again through the cleaning sink in step one.

[0020] As a further solution of the present invention: in the step six, the appearance inspection method is to use an industrial camera and image analysis software to perform image analysis on the screened particles, and the performance inspection includes physical performance testing and chemical performance testing. The physical performance testing method is to use a displacement densitometer to measure the density of the plastic particles, a Shore hardness tester to measure the hardness of the plastic particles, and a tensile strength tester to test the tensile strength. The chemical performance testing method is to use a corrosion resistance tester to evaluate the corrosion resistance of the plastic particles in a specific corrosive medium, and a heat resistance tester to measure the performance changes of the plastic particles in a high temperature environment.

[0021] As a further scheme of the present invention: in step seven, the specific method of waste gas treatment is to set a catalytic oxidation device at the end of the production line, and use MnO2 catalyst to convert harmful substances in the waste gas into harmless substances. The specific method of waste water treatment is to remove suspended matter and particulate matter in the waste water by precipitation, and remove heavy metal ions and organic pollutants in the waste water by chemical reagents. The specific method of waste residue treatment is to sort and recycle recyclable waste residue for reuse, and use incineration power generation to harmlessly treat non-recyclable waste residue.

[0022] As a further solution of the present invention: in the step seven, after the exhaust gas is oxidized by the catalyst, the exhaust gas deep purification unit is used to perform secondary adsorption on the exhaust gas after catalytic oxidation to remove trace amounts of harmful substances. The catalytic oxidation device also includes a photocatalytic oxidation unit, which uses ultraviolet light and TiO2 catalyst to further decompose residual harmful substances in the exhaust gas, and the heat energy in the exhaust gas is recovered through a heat exchanger, and the recovered heat energy is used to preheat the extruder.

[0023] By adopting the above technical solution, compared with the prior art, the beneficial effects of the present invention are:

[0024] 1. The present invention introduces a PCM container in the cooling and shaping step of the integrated production process of environmentally friendly plastic particles, and designs in detail the installation method of the PCM container in the water tank, the type selection of the PCM, and the composition of the temperature control system, thereby achieving precise control of the water temperature in the water tank, maintaining the water temperature within the range of 20°C to 40°C, ensuring the stability and quality of the plastic sheet during the cooling process, and achieving effective utilization of energy and reducing energy consumption through the phase change process of the PCM. In addition, the calculation formula for the cooling time is designed to avoid waste of resources caused by overcooling of the plastic sheet, and also improve production efficiency;

[0025] 2. The present invention realizes an efficient melt extrusion production process by preheating the extruder, using an automatic feeder to feed evenly, and using a die to extrude a sheet shape. At the same time, with the cutting, pulling, pelletizing and other devices, it can ensure the accuracy of product size and improve production efficiency. By strictly screening the plastic particles after pelletizing, removing unqualified particles and impurities, and performing quality inspections such as appearance inspection, physical property test and chemical property test, the product quality is guaranteed to be stable and reliable;

[0026] 3. The present invention preliminarily removes harmful substances in the exhaust gas through the synergistic effect of the MnO2 catalyst and the photocatalytic oxidation unit, and uses the exhaust gas deep purification unit to perform secondary adsorption treatment on the exhaust gas after catalytic oxidation, thereby further removing trace amounts of harmful substances, thereby ensuring that exhaust gas emissions can meet more stringent environmental protection standards. In addition, the heat energy in the exhaust gas is recovered by a heat exchanger and used to preheat the extruder, thereby realizing the recycling of energy and improving energy utilization efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 Schematic diagram of the process steps in an embodiment of the present invention. DETAILED DESCRIPTION

[0028] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0029] Embodiment 1:

[0030] Please see attached Figure 1 The present invention provides an environmentally friendly integrated production process for plastic particles, comprising the following steps:

[0031] Step 1: Raw material preparation and pretreatment: collecting waste plastics, cleaning the waste plastics, removing impurities therein, crushing the cleaned waste plastics into a particle size suitable for extrusion, and adding corresponding reagents to enhance the performance of the crushed plastic particles;

[0032] Step 2: melt extrusion: preheat the extruder, add the crushed waste plastic particles into the hopper of the extruder, and melt the plastic particles and extrude them into sheets through a die;

[0033] Step 3: Cooling and shaping: placing the extruded plastic sheet in a water tank for preliminary cooling, and then using air cooling to further reduce the temperature of the plastic particles;

[0034] Step 4: pelletizing: the cooled and shaped plastic sheet is pulled through a pulling device, and a pelletizer is used to cut the pulled plastic sheet into plastic pellets of a desired length;

[0035] Step 5: Screening: Screen the plastic particles after pelletizing to remove unqualified particles and impurities;

[0036] Step 6: Quality inspection: conduct appearance inspection and performance inspection on the screened plastic particles;

[0037] Step 7: Waste treatment: treatment of waste gas, waste water and waste residue generated during the production process;

[0038] In step one, waste plastics are obtained from community waste plastic recycling points. The specific method of cleaning the waste plastics is to place the collected waste plastics in a cleaning sink, add bio-enzyme cleaning agent and clean water in a ratio of 1:100, stir for 3min-5min and then soak for 1h. The specific method of crushing is to use a plastic crusher to crush the waste plastics into plastic particles with a particle size of 5mm. The corresponding reagents are DOP plasticizer, calcium zinc stabilizer and calcium carbonate filler.

[0039] Specific workflow: We innovatively introduced the PCM (phase change material) container and designed in detail its installation method in the water tank, the type of PCM, and the composition of the temperature control system. In the specific implementation, we selected waxy PCM, whose phase change temperature range is between 25℃-35℃, which can well meet the cooling needs of plastic sheets. The PCM container is tightly installed inside the water tank, with a length of 2.4m, a width of 5.4cm, and a depth consistent with the water tank, ensuring sufficient heat exchange between the PCM and the water in the water tank;

[0040] Through the temperature control system, we monitor the water temperature in the water tank in real time, and calculate the required PCM phase change according to the preset water temperature range (20℃-40℃) and the current water temperature data, and adjust the PCM temperature through the actuator. The experimental data shows that after the plastic sheet is placed in the water tank and initially cooled for 10 minutes, the water temperature in the water tank can quickly stabilize between 28℃-32℃, ensuring the stability and quality of the plastic sheet during the cooling process. At the same time, through the phase change process of PCM, we have achieved effective use of energy, and compared with traditional cooling methods, energy consumption has been reduced by about 20%;

[0041] In addition, we also designed a calculation formula for the cooling time and conducted actual verification. When the current temperature of the plastic sheet is 80°C, the expected temperature is 40°C, and the cooling rate coefficient k is a temperature drop of 5°C per minute, it is calculated that the industrial fan needs to continue cooling for 8 minutes. The experimental results show that after 8 minutes of air cooling, the temperature of the plastic sheet does reach the expected 40°C, avoiding the waste of resources caused by excessive cooling and improving production efficiency.

[0042] Furthermore, by introducing a PCM container in the cooling and shaping step of the integrated production process of environmentally friendly plastic particles, and designing its installation method in the water tank, the type of PCM selected, and the composition of the temperature control system in detail, the water temperature in the water tank can be precisely controlled, and the water temperature is maintained in the range of 20°C to 40°C, thereby ensuring the stability and quality of the plastic sheet during the cooling process. The phase change process of PCM is also used to achieve effective use of energy and reduce energy consumption. In addition, a calculation formula for the cooling time is designed to avoid waste of resources due to excessive cooling of the plastic sheet and improve production efficiency.

[0043] Embodiment 2:

[0044] Based on the first embodiment, please refer to the attached Figure 1 As shown, in step 2, the specific method of melt extrusion is to preheat the extruder temperature to 150°C, feed the pretreated waste plastic particles that meet the particle size requirements into the hopper of the extruder evenly through the plastic particle automatic feeder, extrude them into continuous sheets through the extrusion holes of the die, and cut them into sheets with a thickness of 4.8mm-5.2mm, a width of 4.8mm-5.2cm, and a length of 2m through a cutting machine;

[0045] In step three, the specific method of cooling and shaping is to place the cut plastic sheet into a water tank with a length of 2.2m-2.5m, a width of 5.2cm-5.5cm, and a depth of 1m. A PCM container is provided in the water tank, and the container is filled with waxy PCM, which is used to control the water temperature in the water tank between 20℃-40℃ through the phase change process of PCM. The PCM container is tightly installed inside the water tank. A temperature control system is provided in the water tank. The system includes a temperature sensor, a controller and an actuator. The temperature sensor is used to monitor the water temperature in the water tank in real time and transmit the data to the controller. The controller calculates the required PCM phase change according to the preset water temperature range and the current water temperature data, and adjusts the temperature of the PCM through the actuator. After the plastic sheet is placed in the water tank and initially cooled for 10 minutes, it is moved into the industrial fan cooling area for further cooling according to the current temperature of the plastic sheet. The calculation formula for the cooling time is as follows:

[0046]

[0047] Where t represents the time that the industrial fan needs to continue cooling, t1 is the current temperature of the plastic sheet, t0 is the expected temperature of the plastic sheet, and k is the cooling rate coefficient, which is the average value of the temperature drop of the plastic sheet per minute;

[0048] In step 4, the traction device includes rollers and a transmission belt. The rollers are used to clamp the cooled and shaped plastic sheets and apply traction. The transmission belts are used to transport the plastic sheets between the rollers to the pelletizer. After the plastic sheets are transported to the pelletizer, the pelletizer cuts the plastic sheets into particles with a particle size of 5 cm according to preset parameters.

[0049] In step 5, the specific method of screening is to place the cut plastic particles into a vibrating screen, set the vibration frequency of the vibrating screen to 15Hz-25Hz, the aperture of the first layer of screen to 5cm-5.2cm, and the aperture of the second layer of screen to 4.8cm-5cm. For plastic particles that are too large or too small, they are crushed and cut again, and for particles with impurities, they are cleaned again through the cleaning sink in step 1;

[0050] In step six, the appearance inspection method is to use an industrial camera and image analysis software to perform image analysis on the screened particles. The performance inspection includes physical performance testing and chemical performance testing. The physical performance testing method is to use a displacement densitometer to measure the density of the plastic particles, a Shore hardness tester to measure the hardness of the plastic particles, and a tensile strength tester to test the tensile strength. The chemical performance testing method is to use a corrosion resistance tester to evaluate the corrosion resistance of the plastic particles in a specific corrosive medium, and a heat resistance tester to measure the performance changes of the plastic particles in a high temperature environment.

[0051] Specific work flow: We preheated the extruder to 150℃ and used an automatic feeder to feed the material evenly. Through the extrusion hole of the mold, we extruded the waste plastic particles into a continuous sheet form, and cut them into plastic sheets with a thickness of 5mm, a width of 5cm, and a length of 2m through a cutting machine. The experimental data showed that the dimensional accuracy of the plastic sheets under this process reached ±0.2mm, which met the requirements of subsequent processing;

[0052] In the pelletizing process, we use a traction device consisting of rollers and transmission belts to transport the cooled and shaped plastic sheets to the pelletizer. The pelletizer cuts the plastic sheets into 5cm particles according to the preset parameters. The experimental results show that the qualified rate of pelletizing under this process reaches more than 98%, and the particle size is uniform without impurities.

[0053] By strictly screening the plastic particles after pelletizing, we removed unqualified particles and impurities. During the screening process, we set the vibration frequency of the vibrating screen to 20Hz, the aperture of the first layer of screen to 5.1cm, and the aperture of the second layer of screen to 4.8cm. Experimental data show that the quality of the plastic particles screened out under this process is stable and reliable, with no impurities remaining.

[0054] Furthermore, an efficient melt extrusion production process is achieved by preheating the extruder, using an automatic feeder to feed the material evenly, and using a mold to extrude a sheet shape. At the same time, with the use of cutting, traction, pelletizing and other devices, the product size can be accurate and the production efficiency can be improved. The plastic particles after pelletizing are strictly screened to remove unqualified particles and impurities. Quality inspections such as appearance inspection, physical property testing and chemical property testing are performed to ensure stable and reliable product quality.

[0055] Embodiment three:

[0056] Based on the second embodiment, please refer to the attached Figure 1 As shown, in step seven, the specific method of waste gas treatment is to set up a catalytic oxidation device at the end of the production line, and use MnO2 catalyst to convert harmful substances in the waste gas into harmless substances. The specific method of waste water treatment is to use precipitation to remove suspended matter and particulate matter in the waste water, and chemical reagents to remove heavy metal ions and organic pollutants in the waste water. The specific method of waste residue treatment is to sort and recycle the recyclable waste residue for reuse, and use incineration power generation to treat the non-recyclable waste residue harmlessly;

[0057] In step seven, after the exhaust gas is oxidized by the catalyst, the exhaust gas deep purification unit is used to perform secondary adsorption on the exhaust gas after catalytic oxidation to remove trace amounts of harmful substances. The catalytic oxidation device also includes a photocatalytic oxidation unit, which uses ultraviolet light and TiO2 catalysts to further decompose residual harmful substances in the exhaust gas. The heat energy in the exhaust gas is recovered through a heat exchanger, and the recovered heat energy is used to preheat the extruder.

[0058] Specific work flow: In terms of waste gas treatment, we used the synergistic effect of MnO2 catalyst and photocatalytic oxidation unit to initially remove harmful substances in the waste gas. Subsequently, we used the waste gas deep purification unit to perform secondary adsorption treatment on the waste gas after catalytic oxidation to further remove trace amounts of harmful substances. Experimental data showed that the compliance rate of waste gas emissions under this process reached more than 99%, and the concentration of harmful substances in the waste gas was far lower than the national emission standards;

[0059] In terms of wastewater treatment, we use sedimentation and chemical reagents to remove suspended solids, particulate matter, heavy metal ions and organic pollutants in wastewater. Experimental data show that the water quality of wastewater treated under this process meets the national emission standards, and the treatment efficiency is as high as over 95%;

[0060] In terms of waste residue treatment, we sorted and recycled the recyclable waste residue, and for the non-recyclable waste residue, we used incineration power generation to treat it harmlessly. Experimental data showed that the recycling rate of waste residue under this process reached more than 80%, and the pollutant emissions generated during the incineration power generation process were also far lower than the national emission standards.

[0061] Furthermore, through the synergistic effect of the MnO2 catalyst and the photocatalytic oxidation unit, harmful substances in the exhaust gas are preliminarily removed, and the exhaust gas after catalytic oxidation is subjected to secondary adsorption treatment by the exhaust gas deep purification unit to further remove trace harmful substances, thereby ensuring that exhaust gas emissions can meet more stringent environmental protection standards. In addition, the heat energy in the exhaust gas is recovered by the heat exchanger and used to preheat the extruder, realizing the recycling of energy and improving energy utilization efficiency.

[0062] The above shows and describes the basic principles, main features and advantages of the present invention. It should be understood by those skilled in the art that the present invention is not limited to the above embodiments. The above embodiments and descriptions are only for explaining the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, which fall within the scope of the present invention. The scope of protection of the present invention is defined by the attached claims and their equivalents.

Claims

1. An environmentally friendly integrated production process for plastic particles, characterized in that: The following steps are involved: Step 1: Raw material preparation and pretreatment: collecting waste plastics, cleaning the waste plastics, removing impurities therein, crushing the cleaned waste plastics into a particle size suitable for extrusion, and adding corresponding reagents to enhance the performance of the crushed plastic particles; Step 2: melt extrusion: preheat the extruder, add the crushed waste plastic particles into the hopper of the extruder, and melt the plastic particles and extrude them into sheets through a die; Step 3: Cooling and shaping: placing the extruded plastic sheet in a water tank for preliminary cooling, and then using air cooling to further reduce the temperature of the plastic particles; Step 4: pelletizing: the cooled and shaped plastic sheet is pulled through a pulling device, and a pelletizer is used to cut the pulled plastic sheet into plastic pellets of a desired length; Step 5: Screening: Screen the plastic particles after pelletizing to remove unqualified particles and impurities; Step 6: Quality inspection: conduct appearance inspection and performance inspection on the screened plastic particles; Step seven: waste treatment: treat the waste gas, waste water and waste residue generated during the production process.

2. The environmentally friendly integrated production process of plastic particles according to claim 1, characterized in that: In the step 1, waste plastics are obtained from a community waste plastic recycling point. The specific method for cleaning the waste plastics is to place the collected waste plastics in a cleaning sink, add a bio-enzyme cleaning agent and clean water in a ratio of 1:100, stir for 3 minutes to 5 minutes, and then soak for 1 hour. The specific method for crushing is to use a plastic crusher to crush the waste plastics into plastic particles with a particle size of 5 mm, and the corresponding reagents are DOP plasticizer, calcium zinc stabilizer and calcium carbonate filler.

3. The environmentally friendly integrated production process of plastic particles according to claim 1, characterized in that: In the step 2, the specific method of melt extrusion is to preheat the temperature of the extruder to 150°C, feed the pretreated waste plastic particles that meet the particle size requirements into the hopper of the extruder evenly through the automatic plastic particle feeder, extrude them into continuous sheets through the extrusion holes of the mold, and cut them into sheets with a thickness of 4.8mm-5.2mm, a width of 4.8mm-5.2cm, and a length of 2m through a cutting machine.

4. The environmentally friendly integrated production process of plastic particles according to claim 1, characterized in that: In the step 3, the specific method of cooling and shaping is to place the cut plastic sheet into a water tank with a length of 2.2m-2.5m, a width of 5.2cm-5.5cm, and a depth of 1m. A PCM container is provided in the water tank, and the container is filled with waxy PCM, which is used to control the water temperature in the water tank between 20°C and 40°C through the phase change process of PCM. The PCM container is tightly installed inside the water tank, and a temperature control system is provided in the water tank. The system includes a temperature sensor, a controller and an actuator. The temperature sensor is used to monitor the water temperature in the water tank in real time and transmit the data to the controller. The controller calculates the required PCM phase variable according to the preset water temperature range and the current water temperature data, and adjusts the temperature of the PCM through the actuator. After the plastic sheet is placed in the water tank and initially cooled for 10 minutes, it is moved into the industrial fan cooling area for further cooling according to the current temperature of the plastic sheet. The calculation formula for the cooling time is as follows: Among them, t represents the time that the industrial fan needs to continue cooling, t1 is the current temperature of the plastic sheet, t0 is the expected temperature of the plastic sheet, and k is the cooling rate coefficient, which is the average value of the temperature drop of the plastic sheet per minute.

5. The environmentally friendly integrated production process of plastic particles according to claim 1, characterized in that: In the step 4, the traction device includes rollers and a transmission belt. The rollers are used to clamp the cooled and shaped plastic sheets and apply traction force. The transmission belts are used to transport the plastic sheets between the rollers to the pelletizer. After the plastic sheets are transported to the pelletizer, the pelletizer will cut the plastic sheets into particles with a particle size of 5 cm according to preset parameters.

6. The environmentally friendly integrated production process of plastic particles according to claim 1, characterized in that: In the step five, the specific method of screening is to place the cut plastic particles into a vibrating screen, set the vibration frequency of the vibrating screen to 15Hz-25Hz, the aperture of the first layer of screen to 5cm-5.2cm, and the aperture of the second layer of screen to 4.7cm-4.9cm. For plastic particles that are too large or too small, they are crushed and cut again, and for particles with impurities, they are cleaned again through the cleaning sink in step one.

7. The environmentally friendly integrated production process of plastic particles according to claim 1, characterized in that: In the step six, the appearance inspection method is to use an industrial camera and image analysis software to perform image analysis on the screened particles. The performance inspection includes physical performance testing and chemical performance testing. The physical performance testing method is to use a displacement densitometer to measure the density of the plastic particles, a Shore hardness tester to measure the hardness of the plastic particles, and a tensile strength tester to test the tensile strength. The chemical performance testing method is to use a corrosion resistance tester to evaluate the corrosion resistance of the plastic particles in a specific corrosive medium, and a heat resistance tester to measure the performance changes of the plastic particles in a high temperature environment.

8. The environmentally friendly integrated production process of plastic particles according to claim 1, characterized in that: In step seven, the specific method of waste gas treatment is to set up a catalytic oxidation device at the end of the production line, and use MnO2 catalyst to convert harmful substances in the waste gas into harmless substances. The specific method of waste water treatment is to remove suspended matter and particulate matter in the waste water by precipitation, and remove heavy metal ions and organic pollutants in the waste water by chemical reagents. The specific method of waste residue treatment is to sort and recycle recyclable waste residue for reuse, and use incineration power generation to harmlessly treat non-recyclable waste residue.

9. The environmentally friendly integrated production process of plastic particles according to claim 8, characterized in that: In the step seven, after the exhaust gas is oxidized by the catalyst, the exhaust gas deep purification unit is used to perform secondary adsorption on the exhaust gas after catalytic oxidation to remove trace amounts of harmful substances. The catalytic oxidation device also includes a photocatalytic oxidation unit, which uses ultraviolet light and TiO2 catalyst to further decompose residual harmful substances in the exhaust gas. The heat energy in the exhaust gas is recovered through a heat exchanger, and the recovered heat energy is used to preheat the extruder.

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