Environment-friendly recycling treatment device and recycling treatment method for EPP (Expanded Polypropylene) plastic waste parts

Abstract

The invention relates to an environment-friendly recycling treatment device and method for EPP plastic waste parts, and the environment-friendly recycling treatment device for the EPP plastic waste parts comprises a crusher which is used for feeding EPP waste materials and crushing the EPP waste materials to form a mixed material of particles and powder; the negative pressure fan is connected with an outlet of the crusher so as to extract the crushed mixed material; the cyclone separator comprises a shell, a material inlet and a gas outlet are formed in the top of the shell, and a material outlet is formed in the bottom of the shell; a screening inlet is formed in the top of the screening device, a particle outlet and a powder outlet are formed in the bottom, and a filter screen is arranged between the particle outlet and the powder outlet; and the air seal machine is connected to the particle outlet and is used for downwards outputting the particle materials. The method has the advantages that the material utilization rate is increased, the treatment cost is reduced, and dust pollution is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of environmentally friendly recycling of EPP plastic waste parts, and in particular to an environmentally friendly recycling treatment device and a recycling treatment method for EPP plastic waste parts. Background Art

[0002] EPP products are made from polypropylene foam resin, a type of foam plastic. They are highly skilled and environmentally friendly foam materials with excellent properties such as high strength, high resilience, impact resistance, corrosion resistance, and resistance to breakage. They are widely used in various fields of production and life today, and EPP products have a wide range of applications. However, during the actual production and processing process, molded EPP products may contain some substandard, scrapped, or waste parts due to process and quality issues. Manufacturers typically package these waste parts and send them to upstream raw material manufacturers for processing. However, due to their inherent lack of practicality, upstream manufacturers must pay additional recycling costs when recycling them, resulting in increased costs in the EPP production process and low raw material utilization.

[0003] EPP is a 100% recyclable material. Existing methods for recycling EPP generally use two methods: a cold-pressed foam compressor, which crushes the foam into blocks, and a hot-melt foam machine, which crushes the foam into blocks. Both methods result in blocks that can only be processed into specific products. This has significant processing limitations and hinders widespread reuse. Summary of the Invention

[0004] The purpose of the present invention is to provide an environmentally friendly recycling and treatment device for EPP plastic waste parts to solve the problems of high recycling and treatment costs and large reprocessing limitations of EPP plastic waste parts in the prior art; the purpose of the present invention is also to provide a recycling and treatment method for implementing the device.

[0005] In order to solve the above problems, the environmentally friendly recycling and treatment device for EPP plastic waste parts involved in the present invention adopts the following technical solutions: EPP plastic waste parts environmentally friendly recycling processing device, including Crusher, for feeding EPP waste materials and crushing them into a mixture of granules and powder; A negative pressure fan is connected to the outlet of the pulverizer to extract the pulverized mixed material; The cyclone separator comprises a shell, the top of the shell is provided with a material inlet and a gas outlet, and the bottom of the shell is provided with a material outlet; A sifter has a sifting inlet at the top, a particle outlet and a powder outlet at the bottom, and a filter screen between the particle outlet and the powder outlet; The air shutoff is connected to the particle outlet to allow the particle material to be discharged downward.

[0006] Furthermore, the screening cylinder includes a cylinder body, which is coaxially arranged with the shell, and the inner hole of the cylinder body constitutes a screening channel. The inner diameter of the cylinder body is consistent with the inner diameter of the material outlet. The screening inlet and the particle outlet are distributed at the upper and lower ends of the cylinder body. The filter screen is arranged between the powder outlet and the inner hole to screen the granular material and the powder material when the mixed material approaches the filter screen.

[0007] Furthermore, the cylinder body includes an outer sleeve and an inner sleeve of a coaxial sleeve; An annular space is formed between the outer sleeve and the inner sleeve, the filter screen is arranged on the inner sleeve, and the powder outlet is arranged on the bottom side of the side wall of the outer sleeve.

[0008] Furthermore, the inner cylinder includes two end cylinders that are coaxially arranged in a back-to-back manner and spaced apart. The two end cylinders are respectively inserted and fixed at both ends of the outer cylinder. The filter screen is cylindrical and connected between the two end cylinders.

[0009] Furthermore, a particle conveying pipe for connecting to a silo is provided below the particle outlet.

[0010] Furthermore, the powder outlet is connected to a powder bag.

[0011] Furthermore, a bag dust collector is connected to the gas outlet.

[0012] The recycling method involved in the present invention adopts the following technical solutions: The recycling treatment method comprises the following steps: crushing the EPP waste parts into mixed materials of different particle sizes according to the different degrees of heat exposure of the surface and internal materials of the EPP waste parts and the different degrees of plasticization of the particles, and recycling the particles in the mixed materials for reuse; (1) Crushing: crushing the waste parts into mixed materials, wherein the surface materials are crushed into powder and the internal materials are crushed into particles; (2) Screening: Screen the crushed mixture according to volume, density, and suspension degree to separate the internal particles from the surface powder; (3) Separate storage: transport granular materials and powder materials to different silos for storage; (4) Reprocessing: mixing the granular material with the granular raw material for reprocessing, and cold pressing or hot melting the powder material for reprocessing.

[0013] Furthermore, the screening adopts centrifugal filtration screening. During the centrifugal process, powder particles with small particle size are discharged through filtration, and powder particles with large particle size fall due to their own weight.

[0014] Furthermore, the weight proportion of the particulate material in the mixture of the particulate material and the foamed particle raw material is no more than 30%.

[0015] The beneficial effects of the present invention are as follows: Compared with the existing technology, the environmentally friendly recycling and treatment device for EPP plastic waste parts involved in the present invention, during actual use, forms a particle powder mixture through a crusher, and combines the synergistic effect of a negative pressure fan, a cyclone separator and a screener to achieve material graded recovery, which has the advantages of improving material utilization, reducing processing costs and reducing dust pollution.

[0016] This also effectively solves the problem of mixed particles and powder during the recycling of EPP waste parts. The separated particles can be directly used for injection molding, and the powder can be used as filling material, increasing the utilization rate of recycled materials to over 95%. The closed material transportation process avoids dust pollution and reduces manual intervention. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments: Figure 1 This is a schematic structural diagram of a specific embodiment of the environmentally friendly recycling and treatment device for EPP plastic waste of the present invention; Figure 2 for Figure 1 Another perspective structural diagram; Figure 3 for Figure 2 A cross-sectional view of the separated part; Figure 4 for Figure 2 Schematic diagram of the structure of the middle sifter and powder bag; Figure 5 for Figure 4 Half-section view of the middle screen.

[0018] Description of reference numerals: 1-crusher; 2-negative pressure fan; 3-cyclone separator; 31-housing; 32-material inlet; 33-material outlet; 34-exhaust port; 4- sifter; 41- outer sleeve; 42- end sleeve; 43- filter screen; 44- screening inlet; 45- particle outlet; 46- powder outlet; 5-air shutoff device; 6-conveying pipe; 7-powder bag; 8-bag dust collector; 9-drive motor. DETAILED DESCRIPTION

[0019] In order to make the technical objectives, technical solutions, and beneficial effects of the present invention more clear, the technical solutions of the present invention are further described below with reference to the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention. That is, the embodiments described herein are only some embodiments of the present invention, not all embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings herein can be arranged and designed in various different configurations.

[0020] Among them, the existing EPP waste parts are directly recycled and crushed, and then pressed into blocks by cold pressing or hot melting. The material is completely plasticized, which limits the wide range of reuse scenarios. Upstream manufacturers need to pay additional costs when recycling, resulting in low raw material utilization and increased processing costs for manufacturers. In response to the above problems, the applicant's R&D personnel have conducted repeated experiments and research. After cutting and splitting the products in the factory, the surface layer of the product is directly in contact with the high-temperature steam, which is more completely plasticized, forming a tougher polypropylene wall. The overall structure is squeezed into sheets, and the surface structure is brittle. However, the internal structure is not in direct contact with the high-temperature steam. During the compression molding process, it is affected by the high temperature, and the internal particles are stacked and adhered to each other. In addition, the internal particles form an independent air-tight structure due to the foaming technology, which basically will not be completely plasticized. In response to the above-mentioned material characteristics of existing EPP products, the applicant has developed related recycling and processing equipment to recycle and reuse EPP plastic waste parts.

[0021] As shown in the figure, a specific embodiment of the environmentally friendly recycling and treatment device for EPP plastic waste components, as described in the present invention, exhibits significant differences in particle size after pulverization due to the different levels of heat exposure between the surface and internal materials of the EPP waste components. By analyzing the motion characteristics of the material in an airflow, a method was proposed to physically separate particles from powder using negative pressure conveying combined with centrifugal screening. Further research was conducted on the relationship between material suspension and density, leading to the design of a multi-stage separation structure to ensure efficient grading of materials of varying particle sizes during the screening process.

[0022] The processing device includes a crusher 1, a negative pressure fan 2, a cyclone separator 3, a screening device, and an air lock 5. The crusher 1 crushes the EPP plastic waste into a mixed material, the negative pressure fan 2 pumps the material into the cyclone separator 3 for preliminary separation, and then enters the screening device to pass through the filter 43 to achieve fine screening of particles and powder. The air lock 5 controls the output of the granular material.

[0023] Specifically, the structure of the crusher 1 is consistent with the prior art, and a rotating blade can be used to mechanically crush EPP waste parts. Specifically, a double-axis shearing crusher 1 can be used for this purpose, and the blade spacing can be adjusted to control the particle size of the material. The negative pressure fan 2 is a power device that generates a negative pressure airflow, which can be implemented by a centrifugal fan. The crushed mixed material is sucked into the conveying system through a pipeline connection. In order to simplify the drive, the transmission shaft of the negative pressure fan 2 and the transmission shaft of the crusher 1 can adopt a coaxial connection structure. The drive motor 9 works, driving the crusher 1 to crush the material while also driving the negative pressure fan 2 to extract the crushed material. The cyclone separator 3 uses centrifugal force to achieve gas-solid separation. It adopts a conical cylinder structure. The material inlet 32 ​​is set in the top tangential direction to form a vortex, the material is discharged at the bottom, and the exhaust is discharged at the top. The sifter 4 is implemented in the form of screen separation, and the separation accuracy of particles and powder is controlled by adjusting the mesh size of the screen. The structure and principle of the air lock 5 are consistent with the prior art. The rotary valve that controls the material discharge rate can be implemented as a star-shaped discharge valve, which adjusts the rotor speed to match the downstream conveying speed. At the same time, it prevents the gas in the cyclone separator 3 from being discharged from the material outlet 33.

[0024] Specifically, after EPP waste parts are put into the pulverizer 1, they are crushed into a mixed material, and the airflow generated by the negative pressure fan 2 transports the material to the cyclone separator 3. In the cyclone separator 3, the mixed material and gas move downward in the direction of rotation along the shell 31 of the separator to the material outlet 33. Due to the setting of the air lock 5, the gas pressure increases. At this time, the air pressure near the central axis of the shell 31 is relatively small, and the gas is discharged outward through the exhaust port 34 along the axis. The mixed material stays near the material outlet 33 due to its own weight and centrifugal effect. In the sifter 4, the particulate material of the mixed material is blocked by the filter 43 and falls into the bottom particle outlet 45 for discharge. The powder material passes through the filter 43 and is discharged from the side powder outlet 46. The air lock 5 quantitatively transports the particulate material to the downstream silo through the rotating blades to complete the graded recovery of the material.

[0025] Traditional cold pressing and hot melting cause the material to be compressed into blocks, which limits subsequent processing. Separation and screening enable fine recovery of particles and powder. The hot melting method destroys the physical structure of the material. This solution retains the complete form of the particles and can be directly mixed with the raw material foam particles. It does not require multiple manual sorting and achieves continuous processing through negative pressure conveying and automatic screening, significantly improving production efficiency, reducing corporate production costs, and increasing material utilization.

[0026] Preferably, in order to further meet the screening requirements of particulate materials and powder materials, the sifter 4 includes a cylinder, which is coaxially arranged with the shell 31, and its inner hole constitutes a screening channel, and the screening inlet 44 and the particle outlet 45 are distributed at the upper and lower ends of the cylinder; the filter screen 43 is blocked between the powder outlet 46 and the inner hole to screen the particulate material and the powder material when the mixed material approaches the filter screen 43. The above-mentioned cylinder is a cylindrical cylinder structure, coaxially arranged with the shell 31 of the cyclone separator 3, and the inner diameter of the cylinder is consistent with the inner diameter of the material outlet 33, ensuring that the mixed material remains evenly distributed during the screening process and remains in a centrifugal rotational flow posture in the cylinder. The screening inlet 44 and the particle outlet 45 are distributed at both ends of the cylinder, which can promote the separation of particles and powder with the help of gravity, and at the same time realize dynamic screening of the mixed material through the filter screen 43.

[0027] The main purpose of the design of keeping the inner diameter of the screener 4 consistent with the inner diameter of the material outlet 33 is to effectively extend the rotational flow path of the gas and the mixed material, so that the gas and the mixed material still maintain a downward flow path in the cylinder, which facilitates the subsequent screening and separation of powder and particles through the action of centrifugal force.

[0028] Specifically, the mixed material and gas mixture enters the sifter 4 in a rotational direction from the material outlet 33, and after passing through the screening inlet 44, flows downward in a rotational direction along the side wall of the cylinder under the action of gravity and centrifugation. During the flow process, due to the centrifugal action, the mixed material and gas mixture always has a tendency to flow radially outward. When the mixed material is close to the position where the filter screen 43 is located, it is pushed by the centrifugal force and the gas, and the large-volume granular material is blocked in the filter screen 43, while the small-volume powder material is discharged outward through the powder outlet 46 together with a small amount of gas. Since the bottom of the cylinder is affected by the air-locking effect of the air lock 5, and the outlet diameter of the powder outlet 46 is smaller than the inner diameter of the cylinder, the gas pressure inside the cylinder is greater than the gas pressure inside the separator. Most of the gas is vertically upward from the position near the central axis of the cylinder into the cyclone separator 3, and is discharged outward through the exhaust port 34 along the central axis of the cyclone separator 3. The cylinder and the cyclone separator 3 are coaxially arranged with the same inner diameter, so that the material forms a spiral motion trajectory under the multiple effects of centrifugal force, gravity and wind force, thereby enhancing the separation effect of granular material and powder material.

[0029] The three-dimensional screening space formed by the cylinder, combined with the synergistic effect of centrifugal force, gravity and wind force, enables the material to be screened during the dynamic rotation process, significantly improving the screening efficiency; at the same time, it also avoids screen blockage caused by local accumulation. At the same time, the three-dimensional screening channel extends the screening path of the material and improves the separation accuracy.

[0030] In a preferred embodiment, the sifter 4 comprises an outer sleeve 41 and a coaxially inserted inner sleeve. An annular space is formed between the outer sleeve 41 and the inner sleeve. A filter screen 43 is disposed on the inner sleeve, and a powder outlet 46 is located on the bottom side of the sidewall of the outer sleeve 41. The inner sleeve is coaxially inserted within the outer sleeve 41 and can be implemented as a multi-section, spliced ​​cylinder. The filter screen 43 is disposed on its surface to perform the screening function. By adjusting the diameter difference between the inner and outer sleeves, an annular gap is formed between the outer sleeve 41 and the inner sleeve to accommodate the powder material passing through the filter screen 43. After the mixed material enters the screening channel of the inner sleeve through the screening inlet 44, the larger particles are blocked by the filter screen 43 and fall along the inner sleeve to the particle outlet 45. The powder material then passes through the filter screen 43 and enters the annular space. Because the powder outlet 46, located on the bottom sidewall of the outer sleeve 41, is connected to the annular space, the powder moves downward along the annular space under the action of the swirling wind and is discharged from the powder outlet 46. The split structure of the inner and outer cylinders allows the inner cylinder to be removed separately for maintenance of the filter 43. The design of the annular space prevents powder from clogging during the screening process and enables directional powder extraction.

[0031] More preferably, the inner cylinder includes two coaxially spaced end cylinders 42 arranged in opposite directions. Each end cylinder 42 is inserted and fixed at each end of the outer cylinder 41. A cylindrical filter screen 43 is connected between the two end cylinders 42. The cylindrical filter screen 43 is a filtering structure arranged circumferentially around the inner cylinder. Specifically, it can be made of a rolled metal mesh or nylon mesh. Connected between the two end cylinders 42, it forms a continuous filtering surface, enabling circumferential screening of the mixed material. After the mixed material enters the screening passage of the inner cylinder through the screening inlet 44, the particles fall directly to the particle outlet 45 under the action of gravity. The powdered material passes through the cylindrical filter screen 43 with the airflow into the annular space and is ultimately discharged through the powder outlet 46. The two end cylinders 42 are fixed to the ends of the outer cylinder 41 by an insert sleeve, making the inner cylinder a detachable split structure. When the filter screen 43 needs to be replaced or maintained, the operation can be completed by simply separating the end cylinders 42. Of course, in other embodiments, the end cylinders 42 and the outer cylinder 41 can also be welded. The cylindrical filter screen 43 is arranged circumferentially to form a continuous filtering surface, which has higher screening efficiency and is not easy to accumulate materials, thereby increasing the effective screening area, making the powder material screening more thorough, and avoiding blockage caused by local accumulation of materials on the filtering surface.

[0032] In addition, in order to realize the separate transportation of the mixed material and gas, a particle conveying pipe 6 for connecting to the silo is connected below the particle outlet 45; a powder bag 7 is connected to the powder outlet 46; and a bag dust collector 8 is connected to the gas outlet.

[0033] Among them, after the granular material is discharged from the granular outlet 45 of the screener 4, the material flow is controlled by the air lock 5, and then enters the granular conveying pipe 6. The granular conveying pipe 6 continuously conveys the material to the interior of the silo by mechanical or negative pressure pneumatic means. The silo is connected to the conveying pipe 6 through a sealed interface to ensure that the conveying process is in a closed state. In this process, the granular material and the powder material are completely isolated to avoid secondary mixing, while reducing the contact between the material and the air to prevent moisture or contamination. Ensure that the granular material is quickly transferred to a dedicated storage space after screening to avoid changes in physical properties due to environmental exposure, while improving material transportation efficiency, and providing a pure and stable supply of raw materials for subsequent reprocessing links.

[0034] The powder bag 7 is a filtering device for collecting and storing powder materials after screening. It is made of a breathable textile material that blocks the passage of powder, such as polyester fiber or nylon, and is fixed to the end of the powder outlet 46 by a flange or a clamp. The powder bag 7 can effectively intercept fine powder particles during the screening process, preventing the powder from drifting into the external environment when discharged, and is convenient for centralized collection and processing. After the sifter 4 completes the separation of particles and powder, the powder material enters the powder bag 7 through the powder outlet 46. The air permeability of the powder bag 7 allows air to pass through and trap the powder in the bag, thereby achieving closed collection of the powder. When a certain amount of powder accumulates in the bag, it can be cleaned by disassembling or opening the bottom discharge port, and the collected powder can be transported to a designated area for cold pressing or hot melting reprocessing. This achieves directional collection and closed storage of powder materials, avoids environmental pollution caused by powder drift, and improves the convenience of powder reuse.

[0035] The bag filter 8 is designed to trap micron-sized dust particles carried by the gas as they pass through the gaps between the bag fibers during the mixed material separation process, where they are retained on the filter bag surface. The purified gas is then discharged through the exhaust pipe. The separated gas, carrying residual dust, is then discharged upward through the gas outlet, where the filter bags of the bag filter 8 perform a secondary filtration of the dust-laden gas. When a certain thickness of dust accumulates on the filter bag surface, a pulse backflush device periodically removes the accumulated dust to maintain the filtration resistance within a controllable range. This process achieves deep purification of the exhaust gas before discharge, preventing contamination of the production environment.

[0036] The embodiments of the recycling method of the EPP plastic waste parts environmentally friendly recycling treatment device involved in the present invention are as follows: According to the different degrees of heat exposure and plasticization of the surface and internal materials of the EPP waste parts, the EPP waste parts are crushed to form mixed materials with different particle sizes, and the granular materials in the mixed materials are recycled and reused; the process includes the following steps: (1) Crushing: crushing the waste parts into mixed materials, wherein the surface materials are crushed into powder and the internal materials are crushed into particles; (2) Screening: Screen the crushed mixture according to volume, density, and suspension degree to separate the internal particles from the surface powder; (3) Separate storage: transport granular materials and powder materials to different silos for storage; (4) Reprocessing: mixing the granular material with the granular raw material for reprocessing, and cold pressing or hot melting the powder material for reprocessing.

[0037] The surface material is pulverized into powder by exploiting its high degree of heat and plasticization, which increases its brittleness and toughness. During the pulverization process, the surface particles themselves are preferentially broken into smaller powders. The internal material is pulverized into granules by exploiting its low degree of plasticization and low structural density. During the pulverization process, the particles are preferentially separated, forming larger granules. The volume and density differences in the screening step utilize the differences in the suspension speeds of particles and powder in the airflow for sorting. This can be achieved using a cyclonic separation method that combines centrifugal and gravitational fields, which improves sorting efficiency. Separate silos in the separate storage step use independent sealed containers to store particles and powder, respectively. These can be equipped with six pneumatic conveying pipes and an automatic metering device to prevent cross-contamination. The mixing ratio control in the reprocessing step involves blending the recycled particles with the original particles in a preset ratio. This can be achieved using a loss-in-weight feeder for continuous mixing, ensuring the stability of the recycled material's performance.

[0038] After being processed by pulverizer 1, scrap parts form a mixed material. Due to thermal differences, brittle surface material is preferentially crushed into powder, while incompletely plasticized material within remains in granular form. This mixed material is transported to a screening system via negative pressure airflow. Under the combined effects of centrifugal force and gravity, larger particles fall along the screening channel to particle outlet 45, while smaller powders follow the airflow through filter 43 and enter a powder collection device. The sorted particles and powders, respectively, enter separate silos via air lock 5 and conveying pipe 6. The granular material is then mixed with virgin material for injection molding. The powdered material is then cold-pressed or hot-melt granulated to form recycled raw material.

[0039] Through step-by-step crushing and multi-stage screening, the recycled materials are formed into two forms: granules and powder. The granules can be directly mixed with virgin materials to achieve performance restoration, and the powder can be processed into low-density filling materials through a molding process, which solves the problem of large processing limitations when recycling EPP waste parts. The mixed use of granular materials and virgin materials can reduce the cost of raw material procurement. The cold pressing of powder materials avoids the energy loss of the hot melt process. The sorting and storage process enables materials of different forms to adapt to various processing methods such as injection molding and compression molding, effectively improving the application range and utilization rate of recycled materials.

[0040] Preferably, the screening in the recycling treatment method adopts centrifugal filtration screening. During the centrifugal process, powder particles with small particle size are discharged through filtration, and powder particles with large particle size fall due to their own weight. During the centrifugal filtration screening process, the mixed material is fed into a rotating screening device, and a cylindrical screen is provided inside the device. When the device rotates at high speed, the powder particles are thrown toward the screen under the action of centrifugal force and discharged to the external collection device through the pores of the screen; while the particulate material cannot pass through the screen due to its large volume, and slides down along the inner wall of the screen to the bottom outlet under the action of its own gravity. The speed of the screening device can be adjusted to meet the separation requirements of materials of different particle sizes.

[0041] Centrifugal filtration and screening combine centrifugal force with screening to quickly separate powders from granules while reducing the risk of screen clogging. This is particularly useful for materials with small density differences. This ensures adequate separation of granular and powdered materials, preventing performance degradation caused by mixing during subsequent processing. It also reduces equipment maintenance frequency and improves overall process stability.

[0042] In addition, preferably, the weight proportion of the particulate material in the mixture of particulate material and foamed particle raw material is no more than 30%. The particulate material is granular recycled material formed by crushing the internal materials of waste parts. Specifically, it can be achieved by crushing the incompletely plasticized parts of the EPP waste parts to form particles. Its particle size range can be controlled within a specific range. The granular raw material is unused new polypropylene foam resin raw material. Specifically, it can be achieved by using virgin particles with a particle size similar to that of the recycled particles to ensure mixing uniformity.

[0043] During the reprocessing phase, granular materials are mixed with granular raw materials in a preset ratio. During the mixing process, the amount of granular material incorporated is controlled to less than 30% of the total mass. By limiting the proportion of recycled particles, the mixed material maintains sufficient fluidity during the melt-plasticization stage, avoiding processing temperature fluctuations or molding defects caused by an excessively high proportion of recycled material. In the injection molding process, when the proportion of recycled particles exceeds 30%, the melt viscosity may increase significantly, affecting mold filling. However, controlling the proportion can maintain material processing stability. By limiting the proportion of recycled particles, the efficient utilization of waste materials is achieved while ensuring material properties, while avoiding the impact of excessive incorporation on processing equipment and final product quality. While maintaining injection molding efficiency and product strength, the amount of recycled particles can be increased to a critical value, reducing raw material consumption and avoiding problems such as reduced melt fluidity and increased product shrinkage caused by excessive incorporation.

[0044] Of course, in other embodiments, the mixing ratio of the granular material and the foaming particle raw material can also be arbitrarily designed according to the actual plasticization conditions of the material particles.

[0045] Finally, it should be noted that the above embodiments are only used to illustrate and not to limit the technical solutions of the present invention. Any equivalent substitutions of the present invention and any modifications or partial substitutions that do not depart from the spirit and scope of the present invention should be included in the scope of protection of the claims of the present invention.

Claims

1. EPP plastic waste parts environmentally friendly recycling treatment device, characterized by: include Crusher, for feeding EPP waste materials and crushing them into a mixture of granules and powder; A negative pressure fan is connected to the outlet of the pulverizer to extract the pulverized mixed material; The cyclone separator comprises a shell, the top of the shell is provided with a material inlet and a gas outlet, and the bottom of the shell is provided with a material outlet; A sifter has a sifting inlet at the top, a particle outlet and a powder outlet at the bottom, and a filter screen between the particle outlet and the powder outlet; The air shutoff is connected to the particle outlet to allow the particle material to be discharged downward.

2. The environmentally friendly recycling device for EPP plastic waste according to claim 1 is characterized in that: The screening cylinder includes a cylinder body, which is coaxially arranged with the shell, and the inner hole of the cylinder body constitutes a screening channel. The inner diameter of the cylinder body is consistent with the inner diameter of the material outlet. The screening inlet and the particle outlet are distributed at the upper and lower ends of the cylinder body. The filter screen is arranged between the powder outlet and the inner hole to screen the granular material and the powder material when the mixed material approaches the filter screen.

3. The environmentally friendly recycling device for EPP plastic waste according to claim 2 is characterized in that: The cylinder body comprises an outer sleeve and an inner sleeve of a coaxial sleeve; An annular space is formed between the outer sleeve and the inner sleeve, the filter screen is arranged on the inner sleeve, and the powder outlet is arranged on the bottom side of the side wall of the outer sleeve.

4. The environmentally friendly recycling device for EPP plastic waste according to claim 3 is characterized in that: The inner cylinder comprises two end cylinders which are coaxially arranged in a spaced relationship with each other. The two end cylinders are respectively inserted and fixed at the two ends of the outer cylinder. The filter screen is cylindrical and connected between the two end cylinders.

5. The environmentally friendly recycling device for EPP plastic waste according to any one of claims 1 to 4, characterized in that: A particle conveying pipe for connecting to a silo is connected below the particle outlet.

6. The environmentally friendly recycling device for EPP plastic waste according to any one of claims 1 to 4, characterized in that: The powder outlet is connected to a powder bag.

7. The environmentally friendly recycling device for EPP plastic waste according to any one of claims 1 to 4, characterized in that: The gas outlet is connected to a bag dust collector.

8. A recycling method for EPP plastic waste parts using the environmentally friendly recycling device according to any one of claims 1 to 7, characterized in that: According to the different degrees of heat exposure and plasticization of the surface and internal materials of the EPP waste parts, the EPP waste parts are crushed to form mixed materials with different particle sizes, and the granular materials in the mixed materials are recycled and reused; the process includes the following steps: Crushing: crushing the waste parts into mixed materials, wherein the surface materials are crushed into powder and the internal materials are crushed into particles; Screening: the crushed mixed material is screened according to volume, density, and suspension degree to separate the internal particles from the surface powder; Separate storage: transport granular materials and powder materials to different silos for storage; Reprocessing: mixing granular materials with granular raw materials for reprocessing, and cold pressing or hot melting powder materials for reprocessing.

9. The recycling method according to claim 8, characterized in that: The screening adopts centrifugal filtration screening. During the centrifugal process, powder particles with small particle size are discharged through filtration, and large particle size falls due to its own weight.

10. The recycling method according to claim 8, characterized in that: The weight proportion of the particulate material in the mixture of the particulate material and the foaming particle raw material is no more than 30%.

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