Efficient plasticizing, extruding and foaming system for materials and using method of efficient plasticizing, extruding and foaming system

Abstract

The invention discloses an efficient material plasticizing, extruding and foaming system and a using method.The efficient material plasticizing, extruding and foaming system comprises a plasticizing station and a mixing station, and is characterized in that the plasticizing station is arranged to be a high-speed rotating material plasticator with a non-pressure rotating collision structure; an outlet of the high-speed rotating material plasticator is provided with a parallel double-screw mixing and cooling device used for cooling mixed materials at a low temperature, a using method of the efficient material plasticizing, extruding and foaming system comprises the steps that a foaming agent is injected through the foaming agent injection device, efficient conveying, stirring and mixing are conducted through the parallel double screws, and preliminary cooling is conducted; the high-speed rotary material plasticator has the beneficial effects that the high-speed rotary material plasticator with a non-pressure rotary collision structure is creatively designed, so that secondary feeding becomes possible; no flame retardant is added in the plasticizing process, the materials are cooled in the parallel double screws, the flame retardant does not pass through high temperature and is not decomposed, the flame retardant effect is good, and raw materials are saved.

Description

Technical field:

[0001] The invention belongs to the technical field of polymer plasticization, and more specifically relates to a material efficient plasticization extrusion foaming system and a use method thereof. Background technology:

[0002] At present, large-scale extrusion foaming equipment in the world is relatively expensive, occupies a large area, consumes a lot of energy, melts raw materials slowly, has low production efficiency, and mostly uses material extrusion plasticization.

[0003] Among them, the extrusion plasticization mechanism of PVC materials: According to the three-stage plasticization process of PVC materials in the barrel of the twin-screw extruder, the screw is divided into three areas: solid conveying area, melting area, and melt conveying (extrusion) area.

[0004] 1. Plasticization mechanism of solid conveying area

[0005] In the barrel, the flow, preheating and compaction area of ​​solid polymer (PVC) and its additives is defined as the solid conveying area. First, the flow of solid polymer particles in the hopper into the barrel is achieved by gravity. As the screw rotates, the particles are pushed toward the head of the machine, and the particles in the hopper continue to flow. In the solid conveying area (barrel C1 area), the high molecular and small molecular particles in the PVC material are gradually heated. At the same time, the shearing action of the screw and the friction between the particles also increase the heat of the particles, so that the particles are fully contacted, diffused and penetrated in a dense state.

[0006] In this area, due to the changes in the screw pitch, screw ridge width, etc., the PVC material particles are densely compacted to form a solid bed or solid plug sliding on the screw groove. The movement of the solid plug relies on the friction between the barrel surface and the solid plug, while the friction between the screw and the solid plug prevents the movement of the solid plug. Therefore, in the barrel, the PVC material particles do not move in the same direction, but roll and slip from time to time, and as the screw rotates, "bridges", accumulate behind the "bridge", break through the "bridge", and the process is repeated as the PVC material is extruded and flows in the hopper.

[0007] In this area, the better PVC material extrusion plasticization quality is that PVC is transformed from a glassy state to a highly elastic state. From the perspective of the aggregated structure, 50% to 60% of the PVC resin particles are broken into primary particles, and the surfaces of various additive particles are in full contact and diffusion with the primary particles.

[0008] It is worth pointing out that for stable operation, the height of the solid material in the hopper must be above a certain critical value at all times. Above this critical value, changes in the material surface height will not affect the performance of the extruder. However, if the material surface height is lower than the critical value, it becomes a strong unstable factor. Changes in the solid material surface height will cause changes in the bottom pressure, which will change the operating conditions of the extruder and lead to deterioration of the extrusion plasticization quality of the PVC material.

[0009] 2. Plasticization mechanism of the melting zone

[0010] In the barrel, the area where solid polymer and melt coexist is defined as the melting zone or phase change zone. This zone is the C2 and C3 heating zones. The melting zone is the main part of the extruder, especially the temperature setting (barrel C2 zone, C3 zone, screw core) and screw speed setting, the gap between screws, the gap between screws and barrels, etc., which have an important impact on the extrusion quality of PVC materials. When the PVC material reaches the melting zone, due to changes in the screw pitch, screw edge width, etc., the PVC material particles have generated considerable pressure while being squeezed and compacted. These pressures, together with the softening effect of the surrounding heat medium, turn the compacted particles into a dense "solid bed". At this time, the solid bed is a mixed state composed of a part of PVC high elastic state, a part of PVC glass state, and a small amount of PVC viscous flow state. The solid bed has the shape of a spiral groove and slides in the groove. Due to this relative movement, a velocity distribution is generated in the melt film between the solid bed and the barrel surface. As a result, the melt in the molten film begins to flow toward the screw thread. When it encounters the screw rib, the screw rib "scrapes" the melt from the barrel and gathers in the molten pool at the rear of the screw groove in front of the screw thread. As the solid bed moves along the screw groove, more and more molten material is brought into the molten pool, so the size of the molten pool increases, while the size of the solid bed decreases. The solid bed is gradually destroyed and transported forward in a viscous flow state.

[0011] In this area, the extrusion plasticization quality of PVC materials is better. From the state point of view, PVC is transformed from a high elastic state to a viscous flow state. From the perspective of the aggregate structure, 60-70% of the PVC primary particles are broken into primary particles, and various additive molecules come into contact with the PVC primary particles to form a physical and chemical combination.

[0012] In the melting zone, the factors that improve the plasticization quality of PVC material extrusion are:

[0013] (1) Increase the screw speed (2) Increase the barrel setting temperature in the melting zone (3) Appropriate screw-barrel clearance For a specific PVC profile production formula, there should be an optimal barrel temperature in the melting zone.

[0014] 3. Plasticization mechanism of melt conveying zone

[0015] In the barrel, the solid polymer is completely converted into a melt, and the part where the melt is forcibly transported to the head is defined as the melt transport zone (barrel C4 heating zone). In this area, the molten macromolecules further react with various additives under the action of shear, and the secondary particles and a small amount of primary particles together form a crystal. This part of the primary particles can improve the strength and toughness of the final material. When the material containing this crystalline body is extruded and cooled, under the action of external force, the primary particles can hinder the movement of the primary particles to achieve an increase in strength; and because the primary particles have a large surface area, they can absorb part of the impact energy when impacted, thereby improving toughness.

[0016] The limitations of the method principle lead to certain disadvantages in the above method, such as low production efficiency, poor flame retardant effect, low flame retardant utilization efficiency, poor cooling efficiency, and insufficient quality of finished products. Summary of the invention:

[0017] In order to solve the above problems and overcome the shortcomings of the prior art, the present invention provides a material high-efficiency plasticizing extrusion foaming system and method with high production efficiency, high flame retardant utilization efficiency, high cooling efficiency and good finished product quality, which can effectively solve the problems of low production efficiency, poor flame retardant effect, low flame retardant utilization efficiency, poor cooling efficiency and insufficient finished product quality.

[0018] The specific technical solution of the present invention to solve the above technical problems is: a high-efficiency material plasticizing extrusion foaming system, including a plasticizing station and a mixing station, characterized in that the plasticizing station is configured as a high-speed rotating material plasticizing machine with a pressureless rotating collision structure, and the outlet of the high-speed rotating material plasticizing machine is provided with a parallel twin-screw mixing cooling device for low-temperature cooling of the mixed material, and a foaming agent injection device is also provided at the inlet of the parallel twin-screw mixing cooling device, and the outlet of the parallel twin-screw mixing cooling device is provided with a high-efficiency mixing cooling device through a screen changer 7.

[0019] Furthermore, the high-speed rotating material plasticizer includes a hollow body, a transmission structure is provided on one side of the body, a high-speed motor with a rotation speed of 2000-6000 rpm is provided on one side of the transmission structure, the output end of the high-speed motor is connected to the transmission structure, and the other end of the transmission structure is connected to a transmission shaft passing through the axis of the body, and the transmission shaft is arranged into multiple sections, including a conveying thread section arranged at one end of the transmission shaft, a preset number of collision and melting sections, a porous plate and a positive thread section II, the porous plate is sleeved on the outside of the transmission shaft located at the outlet end of the reverse thread section, the collision and melting section is composed of a positive thread section I and a reverse thread section, and the pitch of the positive thread section I is greater than the pitch of the reverse thread section.

[0020] Furthermore, a high-frequency heater for heating is arranged on the outside of the body of the high-speed rotating material plasticizing machine, and a discharge port is arranged at the bottom of one side of the body.

[0021] Furthermore, the parallel twin-screw mixing and cooling device is configured as a parallel twin-screw for efficient conveying, stirring, mixing, and preliminary cooling; the model of the parallel twin-screw is any one of type 75, type 86, type 95, type 110, or type 135.

[0022] Furthermore, the high-efficiency mixing and cooling device comprises a static mixer, a dynamic mixer and a single-screw extruder, and the model of the single-screw extruder is any one of type 200, type 250, type 300, type 400 or type 500.

[0023] A method for using a material efficient plasticizing extrusion foaming system is characterized in that materials are placed in a high-speed rotating material plasticizing machine, the high-speed rotating materials collide with each other to generate heat energy, instantly melt the materials, the plasticized materials are transported to a parallel twin-screw mixing and cooling device, and a foaming agent is injected by a foaming agent injection device, and the materials are efficiently transported, stirred, mixed, and preliminarily cooled by the parallel twin-screws. The preliminarily cooled materials enter the efficient mixing and cooling device through a screen changer for mixing and cooling. The efficient mixing and cooling device includes a static mixer, a dynamic mixer, and a single-screw extruder; the cooled and mixed materials are pressure-released and foamed through a die head mold to form a foamed product.

[0024] Furthermore, the material is any one of PS, PE, PLA or PET.

[0025] Furthermore, the foaming agent is any one of CO2, alcohol, Freon or butane.

[0026] Furthermore, the foamed product is any one of a foamed board, a sheet, a tube or a profile.

[0027] The beneficial effects of the present invention are as follows: the present invention solves the problem that the flame retardant effect of products produced by conventional plasticizing extrusion equipment is poor.

[0028] The high-speed rotating material plasticizer with a creatively designed pressure-free rotating collision structure replaces the traditional high-pressure screw heating and melting, making secondary feeding possible;

[0029] The existing foaming equipment avoids the large shear heat and high temperature during the plasticization of raw materials, which causes serious decomposition of flame retardants, reduces the flame retardant effect, and increases the amount of flame retardants used. The high-speed rotating material plasticizer is used. Flame retardants are not added during the plasticization process. Instead, powdered flame retardants are added when the materials enter the parallel twin screws after plasticization. The materials are cooled in the parallel twin screws. The flame retardants do not go through high temperatures and do not decompose. The flame retardant effect is good, saving raw materials.

[0030] It is precisely because of the introduction of the high-speed rotating material plasticizer with a pressureless rotating collision structure that heating and melting under pressureless conditions are achieved, so that the parallel twin-screw mixing and cooling device can be fully used for low-temperature cooling of mixed materials. The parallel twin-screw mixing and cooling device no longer bears the task of plasticizing materials, but uses its super mixing ability to promote the mixing of materials and foaming agents, and cools the materials, and then enters the three-stage high-efficiency mixing and cooling device for mixing and cooling. Therefore, the cooling capacity is doubled, and the foaming output of equipment with the same specifications is also doubled. Description of the drawings:

[0031] Attached Figure 1 It is a schematic diagram of the present invention;

[0032] Attached Figure 2 Schematic diagram of the high-efficiency mixed cooling device of the present invention; in the accompanying drawings:

[0033] 1. Plasticizing station 2. Parallel twin-screw mixing and cooling device 3. High-efficiency mixing and cooling device 4. Cooler 5. Head mold 6. Auxiliary machine 7. Screen changer 8. Foaming agent injection device, 11. High-speed motor, 12. Transmission structure, 13. Feed inlet, 14. Positive thread section I, 15. Reverse thread section, 16. High-frequency heater, 17. Insulation cylinder, 18. Discharge port, 19. Positive thread section II, 20. Perforated plate, 21. Conveying thread section. Specific implementation method:

[0034] In the description of the present invention, specific details are only for a full understanding of the embodiments of the present invention, but those skilled in the art should know that the implementation of the present invention is not limited to these details. In addition, well-known structures and functions are not described or shown in detail to avoid blurring the key points of the embodiments of the present invention. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0035] The specific implementation mode of the present invention is as follows: a material efficient plasticizing extrusion foaming system, comprising a plasticizing station 1 and a mixing station, characterized in that the plasticizing station 1 is configured as a high-speed rotating material plasticizing machine with a pressureless rotating collision structure, the high-speed rotating material plasticizing machine comprises a hollow body, one side of the body is provided with a transmission structure 12, one side of the transmission structure 12 is provided with a high-speed motor 11 with a rotation speed of 2000-6000 rpm, the output end of the high-speed motor 11 is connected to the transmission structure 12, and the other end of the transmission structure 12 is connected to a transmission structure 12 through the body axis. The transmission shaft is arranged into multiple sections, including a conveying thread section 21 arranged at one end of the transmission shaft, a preset number of collision and melting sections, a porous plate 20 and a positive thread section II 19, the porous plate 20 is sleeved on the outside of the transmission shaft located at the outlet end of the reverse thread section 15, the collision and melting section is composed of a positive thread section I 14 and a reverse thread section 15, the pitch of the positive thread section I 14 is greater than the pitch of the reverse thread section 15, a high-frequency heater 16 for heating is arranged on the outside of the body of the high-speed rotating material plasticizer, and a discharge port 18 is arranged at the bottom of one side of the body;

[0036] The outlet of the high-speed rotating material plasticizer is provided with a parallel twin-screw mixing and cooling device 2 for low-temperature cooling of the mixed material, the inlet of the parallel twin-screw mixing and cooling device 2 is also provided with a foaming agent injection device 8, and the outlet of the parallel twin-screw mixing and cooling device 2 is provided with a high-efficiency mixing and cooling device 3 through a screen changer 7;

[0037] The parallel twin-screw mixing and cooling device 2 is configured as a parallel twin-screw for efficient conveying, stirring, mixing, and preliminary cooling; the model of the parallel twin-screw is any one of type 75, type 86, type 95, type 110, or type 135;

[0038] The high-efficiency mixing and cooling device 3 includes a static mixer, a dynamic mixer and a single-screw extruder, wherein the single-screw extruder is any one of type 200, type 250, type 300, type 400 or type 500.

[0039] The invention discloses a method for using a material efficient plasticizing extrusion foaming system. The material is put into a high-speed rotating material plasticizing machine. The material is any one of PS, PE, PLA or PET. The high-speed rotating materials collide with each other to generate heat energy and melt the material instantly. The plasticized material is transported to a parallel twin-screw mixing and cooling device 2, and a foaming agent is injected into a foaming agent injection device 8. The foaming agent is any one of CO2, alcohol, Freon or butane. The parallel twin-screws are used for efficient transportation, stirring, mixing and preliminary cooling. The material after preliminary cooling enters a high-efficiency mixing and cooling device 3 through a screen changer 7 for mixing and cooling. The high-efficiency mixing and cooling device 3 comprises a static mixer, a dynamic mixer and a single-screw extruder. The cooled and mixed material is pressure-released and foamed through a die head mold 5 to form a foamed product. The foamed product is any one of a foamed board, a sheet, a tube or a profile.

[0040] In order to more intuitively demonstrate the process advantages of the method for using the material efficient plasticizing extrusion foaming system of the present invention,

[0041] When using, the specific operations are as follows:

[0042] Materials such as PS, PE, PLA, and PET are placed in a high-speed rotating material plasticizer 1 with a pressureless rotating collision structure. The high-speed rotating materials collide with each other to generate heat energy and melt the materials instantly. Since the melting time of the materials is short and the thermal decomposition is small, the materials can maintain good physical properties. The device has a strong plasticizing capacity and can reach 1000KG-3000KG per hour. The plasticized materials are transported to the parallel twin-screw mixing and cooling device 2, and the foaming agent CO2, alcohol, freon, butane, etc. are injected by the foaming agent injection device 8. The materials are efficiently transported, stirred, mixed, and preliminarily cooled by the parallel twin screws. The specifications of the parallel twin screws include 75, 86, 95, 110, 135, etc. The materials after preliminary cooling enter the high-efficiency mixing and cooling device 3 through the screen changer 7 for mixing and cooling. The high-efficiency mixing and cooling device 3 includes a static mixer; a dynamic mixer; a 200, 250, 300, 400, 500 single-screw extruder, etc. The cooled and mixed materials are released from pressure and foamed through the die head mold 5 to form a foamed product. The foamed products can be foamed boards, sheets, tubes, profiles, etc. The device can be used to produce high-quality foamed products such as films, sheets, tubes, rods, profiles, etc. The products are widely used in catering, packaging, medical and other fields with excellent high impact resistance and high thermal insulation performance, and have broad application prospects.

[0043] At this time, a. The high-speed plasticizing device uses high-speed rotating materials to collide with each other, generate heat energy, and instantly melt the materials. Since the material melting time is short and the thermal decomposition is small, the material can maintain good physical properties. The device has a strong plasticizing capacity and can reach 1000KG-3000KG per hour. The device is small in size, about 1 / 3 of the plasticizing output equipment, and is pressure-free. The high-speed rotating material plasticizing machine with a pressure-free rotating collision structure replaces the traditional high-pressure screw in the melting zone, making secondary feeding possible;

[0044] b. The second-stage parallel twin screws no longer bear the task of plasticizing the material. Instead, they use their super mixing ability to mix the material with the foaming agent and cool the material. The material then enters the third-stage high-efficiency mixing and cooling device for mixing and cooling. Thus, the cooling capacity is doubled, and the foaming output of the equipment of the same specification is also doubled;

[0045] c. In view of the large shear heat and high temperature during the plasticization of raw materials in domestic foaming equipment, the flame retardant decomposes seriously, which reduces the flame retardant effect and can only increase the dosage of flame retardant. At this time, this process creatively does not add flame retardant during the plasticization process, but adds powdered flame retardant when the material enters the parallel twin screw after plasticization. The material is cooled in the parallel twin screw. The flame retardant does not go through high temperature and does not decompose. The flame retardant effect is good, which saves raw materials. About 10 yuan of flame retardant is saved for each cubic meter of foamed product. According to the minimum amount of 700 cubic meters of foamed products per day, 7,000 yuan of flame retardant can be saved per day.

[0046] In summary: the present invention solves the problem that the flame retardant effect of products produced by traditional plasticizing extrusion equipment is poor.

[0047] The high-speed rotating material plasticizer with a creatively designed pressure-free rotating collision structure replaces the traditional high-pressure screw heating and melting, making secondary feeding possible;

[0048] The existing foaming equipment avoids the large shear heat and high temperature during the plasticization of raw materials, which causes serious decomposition of flame retardants, reduces the flame retardant effect, and increases the amount of flame retardants used. The high-speed rotating material plasticizer is used. Flame retardants are not added during the plasticization process. Instead, powdered flame retardants are added when the materials enter the parallel twin screws after plasticization. The materials are cooled in the parallel twin screws. The flame retardants do not go through high temperatures and do not decompose. The flame retardant effect is good, saving raw materials.

[0049] It is precisely because of the introduction of the high-speed rotating material plasticizer with a pressureless rotating collision structure that heating and melting under pressureless conditions are achieved, so that the parallel twin-screw mixing and cooling device can be fully used for low-temperature cooling of mixed materials. The parallel twin-screw mixing and cooling device no longer bears the task of plasticizing materials, but uses its super mixing ability to promote the mixing of materials and foaming agents, and cools the materials, and then enters the three-stage high-efficiency mixing and cooling device for mixing and cooling. Therefore, the cooling capacity is doubled, and the foaming output of equipment with the same specifications is also doubled.

Claims

1. A method for using a material efficient plasticizing extrusion foaming system, characterized in that: The material is placed in a high-speed rotating material plasticizing machine, and the high-speed rotating materials collide with each other to generate heat energy and melt the material instantly. The plasticized material is transported to a parallel twin-screw mixing and cooling device (2), and a foaming agent is injected into the foaming agent injection device (8). The parallel twin-screws are used for efficient transportation, stirring, mixing, and preliminary cooling. The preliminary cooled material enters a high-efficiency mixing and cooling device (3) through a screen changer (7) for mixing and cooling. The high-efficiency mixing and cooling device (3) includes a static mixer, a dynamic mixer, and a single-screw extruder. The cooled and mixed material is released from pressure through a die head mold (5) to foam to form a foamed product.

2. The method for using the material efficient plasticizing extrusion foaming system according to claim 1, characterized in that The material efficient plasticizing extrusion foaming system comprises a plasticizing station (1) and a mixing station. The plasticizing station (1) is configured as a high-speed rotating material plasticizing machine with a pressureless rotating collision structure. The outlet of the high-speed rotating material plasticizing machine is provided with a parallel twin-screw mixing and cooling device (2) for low-temperature cooling of the mixed material. The inlet of the parallel twin-screw mixing and cooling device (2) is also provided with a foaming agent injection device (8). The outlet of the parallel twin-screw mixing and cooling device (2) is provided with a high-efficiency mixing and cooling device (3) through a screen changer (7).

3. The method for using the material efficient plasticizing extrusion foaming system according to claim 2, characterized in that The high-speed rotating material plasticizing machine comprises a hollow body, a transmission structure (12) is arranged on one side of the body, a high-speed motor (11) with a rotation speed of 2000-6000 rpm is arranged on one side of the transmission structure (12), the output end of the high-speed motor (11) is connected to the transmission structure (12), the other end of the transmission structure (12) is connected to a transmission shaft passing through the axis of the body, the transmission shaft is arranged into a plurality of sections, including a conveying thread section (21) arranged at one end of the transmission shaft, a preset number of collision and melting sections, a porous plate (20) and a positive thread section II (19), the porous plate (20) is sleeved on the outer side of the transmission shaft at the outlet end of the reverse thread section (15), the collision and melting section is composed of a positive thread section I (14) and a reverse thread section (15), the pitch of the positive thread section I (14) is greater than the pitch of the reverse thread section (15).

4. The method for using the material efficient plasticizing extrusion foaming system according to claim 3 is characterized in that A high-frequency heater (16) for heating is arranged on the outside of the body of the high-speed rotating material plasticizing machine, and a discharge port (18) is arranged at the bottom of one side of the body.

5. The method for using the material efficient plasticizing extrusion foaming system according to claim 2, characterized in that The parallel twin-screw mixing and cooling device (2) is configured as a parallel twin-screw for efficient conveying, stirring, mixing, and preliminary cooling; the model of the parallel twin-screw is any one of type 75, type 86, type 95, type 110, or type 135.

6. The method for using the material efficient plasticizing extrusion foaming system according to claim 2, characterized in that The high-efficiency mixing and cooling device (3) comprises a static mixer, a dynamic mixer and a single-screw extruder, and the single-screw extruder is any one of type 200, type 250, type 300, type 400 or type 500.

7. The method for using the material efficient plasticizing extrusion foaming system according to claim 1, characterized in that The material is any one of PS, PE, PLA or PET.

8. The method for using the material efficient plasticizing extrusion foaming system according to claim 1, characterized in that The foaming agent is any one of CO2, alcohol, freon or butane.

9. The method for using the material efficient plasticizing extrusion foaming system according to claim 1, characterized in that The foamed product is any one of a foamed plate, a sheet, a tube or a profile.

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