Device for continuously extruding polymer foamed beads

Abstract

The utility model discloses a device for continuously extruding polymer foamed beads, which comprises a pelletizing system, an air control system and a temperature control system, the air supply volume and the temperature are regulated and controlled through the pelletizing system, the air control system and the temperature control system, and the pressure of a cutter pressed on an extruder die is regulated and controlled in cooperation with continuous extrusion foaming equipment. The foaming beads with smooth, bright, round and full surfaces, controllable multiplying power and high percentage of close area can be obtained, the phenomena of shrinkage, adhesion, uncontrollable multiplying power, surface chap and the like of the foaming beads caused by unstable temperature in the extrusion foaming granulation process are greatly improved, and the stability and uniformity of the extruded foaming beads are obviously improved. Compared with a traditional kettle pressure foaming production mode, the macromolecule foaming bead device can effectively improve the preparation efficiency of foaming beads, and has the advantages of continuity, high production efficiency, short production period, cost saving and the like.

Description

Technical Field

[0001] The utility model belongs to the field of production of foamed beads of polymer materials such as plastics and rubber, and in particular relates to a device for continuously extruding polymer foamed beads. Background Art

[0002] The traditional production methods of foam beads are: screw extrusion to make particles (plastics, rubber and other polymer materials are extruded through a twin-screw extruder to obtain particles with a particle size of 0.5-1.0mm), high-temperature and high-pressure autoclave foaming / impregnation (particles are put into a reactor and a foaming agent is added and heated for a period of time before being released) and steam foaming (the particles after foaming / impregnation are heated with hot steam and then expanded / foamed for a second time to obtain foam beads).

[0003] Patent document CN112705137B discloses an autoclave foaming device and method for polypropylene foam beads. The production of foam beads using this device is not continuous, has high energy consumption, complicated steps, and high equipment requirements (special equipment for pressure vessels). In addition, multiple heating will cause thermal degradation of most plastics and rubbers, which has a great impact on their mechanical properties.

[0004] Patent document CN113736048A discloses a method and device for continuously preparing foamed thermoplastic polyurethane elastomer beads. In the production process of thermoplastic polyurethane elastomer beads, in order to reduce the cooling of the die head by the circulating water of underwater pelletizing, which leads to excessive pressure on the extruder die head, the polyurethane elastomer melt needs to be pre-foamed in a low-pressure foaming melting chamber, and then the thermoplastic polyurethane elastomer beads are obtained by an underwater pelletizing device. Since the polyurethane elastomer melt is pre-foamed in the low-pressure foaming melting chamber, the foaming agent has overflowed from the polyurethane elastomer melt in large quantities, so the thermoplastic polyurethane elastomer beads obtained by the underwater pelletizing device have a low foaming ratio and a large density, and the high water temperature of the circulating water of underwater pelletizing also greatly increases the energy consumption of the production process and increases the production cost.

[0005] Patent document CN220784505U discloses an air-cooled die face hot cutting machine, which is mainly composed of a motor, a universal joint, a hot cutting knife disc, and a pelletizing cover, and is used to cooperate with an extruder to produce polymer particles. During the operation of this type of die face air-cooled hot cutting machine, the greater the air volume, the faster the cooling speed, and the less likely the particles will stick together. However, if this type of equipment is used to produce foam beads, the cooling speed is too fast, which will cause the surface of the foam beads to solidify rapidly, resulting in low foaming ratio of the foam beads, surface cracking and other phenomena. Similarly, the heat generated by the continuous friction of the cutter on the extruder die and the heat transfer of the extruder die itself will cause the temperature to be too high, causing the foam beads to shrink and sandwich, which has a great impact on the stability of the entire continuous production process. The existing wind cutting device is not suitable for the continuous production of extruded foam beads.

[0006] In summary, it is crucial to develop a polymer foaming bead device with continuity, high foaming ratio, low cost, low energy consumption, easy operation and high production stability. Summary of the invention

[0007] In order to solve the problems existing in the prior art, the utility model provides a device for continuously extruding polymer foam beads. The device can produce foam beads with a smooth, bright, round and full surface, controllable ratio and high closed cell rate through the cooperation of a pelletizing system, an air supply system and a temperature control system. The production process is continuous, the production efficiency is high, the production cycle is short, and the production cost of the foam beads is effectively reduced.

[0008] A device for continuously extruding polymer foam beads comprises a base, a sliding guide rail arranged on the base, and a working platform movable along the sliding guide rail, wherein the working platform comprises an air supply system, a pelletizing system and a temperature control system;

[0009] The air supply system includes a fan, an air supply channel, a pelletizing hood and an air outlet channel connected to the fan in sequence, the pelletizing hood is connected to the extruder so that the material extruded by the extruder enters the pelletizing hood; the air supply system is used to cool the material in the pelletizing hood and bring the material away from the die surface in time to the discharge port for collection;

[0010] The pelletizing system comprises a driving motor, a knife holder connected to the driving motor and located in a pelletizing cover, and a cutter is fixed on the knife holder; the pelletizing system drives the knife holder and the cutter to rotate through the driving motor to cut the material extruded by the extruder into pellets;

[0011] The temperature control system includes a heating jacket arranged on the air supply channel, an air inlet thermocouple arranged at the connection between the air supply channel and the pelletizing hood, and an air outlet thermocouple arranged at the connection between the pelletizing hood and the discharge channel; the temperature control system is used to adjust the foaming environment temperature in the pelletizing hood;

[0012] By adjusting the speed of the driving motor in the pelletizing system, the length of the foamed beads is controlled, and the temperature of the foaming environment is adjusted by the temperature control system to obtain foamed beads that meet the requirements. The air volume is adjusted by the air supply system to blow the obtained foamed beads to the discharge port for collection.

[0013] Preferably, the base is provided with leveling support feet for adjusting the level of the equipment and fixing the position of the equipment.

[0014] Preferably, a transmission guide rod is provided on the base, and the transmission guide rod is fixed to the base through a guide rod fixing plate. The transmission guide rod can be a pneumatic guide rod, a hydraulic guide rod or an electric guide rod.

[0015] Preferably, a guide rail slider is provided on the sliding guide rail, and the guide rail slider is connected to the working platform. The guide rail slider drives the working platform to move along the sliding guide rail under the action of a transmission guide rod.

[0016] Preferably, the air supply system is provided with an air volume control valve, which is arranged at the connection between the fan and the air supply channel and is used to adjust the air supply volume.

[0017] Preferably, observation windows are provided on both sides of the pelletizing cover for real-time observation of the pelletizing condition of the equipment.

[0018] The extruder die is installed on the extruder. Preferably, the discharge hole diameter of the extruder die is 0.6-3 mm; the number of discharge holes on the extruder die is 2-20.

[0019] Preferably, the knife holder is a 2-7 cutter knife holder.

[0020] Preferably, the heating jacket is in electric heating jacket temperature control mode, and can also be set to oil ring temperature control mode, water ring temperature control mode or electric heating wire temperature control mode as needed.

[0021] Preferably, a storage bin is also provided on the base, and the storage bin is used to collect materials blown out from the discharge port.

[0022] Preferably, the working platform further comprises an equipment electrical box and a control panel, on which a main equipment switch, an emergency stop button, a heating switch, a temperature adjustment display, a motor switch, a speed adjustment knob, a speed display, a fan switch, and an air volume adjustment knob are arranged. The equipment is turned on and working parameters are adjusted through the equipment electrical box and the control panel.

[0023] Compared with the prior art, the present invention has at least the following beneficial effects:

[0024] (1) The air volume of the continuous extrusion polymer foam beads device of the utility model is adjustable. The utility model can adjust the air volume of the fan so that the cut foam beads can be taken away from the die surface in time and collected at the discharge port, while the air volume is too high to take away too much heat from the extruder die, causing the temperature of the extruder head to drop suddenly and the pressure to increase suddenly, making it difficult to extrude the material and interrupting the foaming, and causing damage to the equipment;

[0025] (2) The pressure of the cutter of the continuous extrusion polymer foam beads device on the extruder die is adjustable. The position of the working platform relative to the extruder can be adjusted so that the cutter of the pelletizing system can fit the extruder die perfectly to cut the foam beads without causing the drive motor to be overloaded or even difficult to rotate, thereby increasing energy loss and damaging the equipment.

[0026] (3) The ambient temperature required for foaming of the continuous extrusion polymer foam beads device of the utility model is controllable. The utility model can adjust the foaming ambient temperature in the pelletizing hood through the temperature control system to adjust the ratio, surface morphology, cell size, and open / closed cell ratio of the foam beads;

[0027] (4) The continuous extrusion polymer foam bead device of the utility model can continuously produce foam beads with controllable ratio, particle size, pores, openings and surface morphology. Compared with the traditional high-pressure autoclave foaming production method, the equipment has the advantages of controllable temperature and air volume, safety and high efficiency, making the production of foam beads continuous, with high production efficiency and short production cycle, effectively reducing the production cost of foam beads. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 It is a schematic diagram of the overall structure of a device for continuously extruding polymer foam beads according to an embodiment;

[0029] Figure 2 It is a schematic diagram of the internal structure of the continuous extrusion polymer foam beads device of the embodiment;

[0030] Figure 3 It is a schematic diagram of the structure before and after the working platform of the continuous extrusion polymer foam beads device is connected to the extruder in the embodiment;

[0031] Figure 4 It is a schematic diagram of the apparent morphology of the beads obtained under different temperature control conditions of the continuous extrusion polymer foaming bead device; Figure 4 -ⅰNot issued; Figure 4 -ⅱFull; Figure 4 -ⅲSandwich; Figure 4 -ⅳ Shrinkage.

[0032] The following are the descriptions of the reference numerals:

[0033] 1- Equipment base; 2- Working platform; 3- Extruder die; 4- Extruder; 5- Control panel; 6- Equipment electrical box; 7- Adjustable leveling support feet; 8- Sliding guide rails; 9- Pneumatic guide rods; 10- Storage bin; 11- Guide rail slider; 12- Guide rod fixing plate; 13- Servo motor; 14- Knife holder; 15- Cutter; 16- Fan; 17- Air volume control valve; 18- Air supply channel; 19- Pelletizing hood; 20- Observation window; 21- Discharge channel; 22- Heating jacket; 23- Inlet thermocouple; 24- Outlet thermocouple. DETAILED DESCRIPTION

[0034] In order to make the content of the utility model more clearly understood, the utility model is further described in detail below based on specific embodiments and in conjunction with the accompanying drawings.

[0035] See also Figure 1-3A device for continuously extruding polymer foam beads comprises a base 1, a sliding guide rail 11 arranged on the base, and a working platform 2 movable along the sliding guide rail, wherein the working platform comprises an air supply system, a pelletizing system and a temperature control system.

[0036] The base 1 is provided with leveling support feet 7 at four corners for adjusting the level of the device and fixing the position of the device.

[0037] A pneumatic guide rod 9 is provided on the base 1 , and the pneumatic guide rod 9 is fixed on the base 1 through a guide rod fixing plate 12 , and the pressure of the pneumatic guide rod 9 is adjustable.

[0038] The sliding guide rail 8 is fixed on the equipment base 1, and a guide rail slider 11 is provided on the sliding guide rail 8. The guide rail slider 11 is fixed at the four corners of the bottom surface of the working platform 2 and is sleeved on the sliding guide rail 8. The guide rail slider 8 drives the working platform 2 to move along the sliding guide rail 8 under the action of the pneumatic guide rod 9. By adjusting the pressure of the pneumatic guide rod 9 to adjust the position of the working platform relative to the extruder, the cutter 15 can fit the die perfectly and cut the intact foaming beads, and the servo motor 13 will not be overloaded or even difficult to rotate due to too much pressure, which will increase energy loss and damage the equipment.

[0039] The air supply system includes a fan 16, an air volume control valve 17, an air supply channel 18, a pelletizing cover 19 and a discharge channel 21. The fan 16 is connected to the air volume control valve 17, the air supply channel 18, the pelletizing cover 19 and the discharge channel 21 in sequence. Observation windows 20 are provided on both sides of the pelletizing cover 19 for real-time observation of the pelletizing condition of the equipment. When the air supply system is working, the fan 16 supplies air through the air volume control valve 17, and passes through the air supply channel 18, the pelletizing cover 19 and the discharge channel 21 in sequence. By adjusting the air volume of the fan 16, the cut foaming beads can be taken away from the die surface in time and collected at the discharge port, and the air volume will not be too high to take away too much heat from the extruder die, so that the temperature of the extruder head drops sharply and the pressure increases sharply, and the material is difficult to extrude, so that the foaming is interrupted, causing equipment damage.

[0040] The pelletizing system includes a servo motor 13, a tool holder 14 and a cutter 15. The servo motor 13 is connected to the tool holder 14 inside the pelletizing cover 19 through a universal shaft, the cutter 15 is fixed on the tool holder 14, and the extruder die 3 is installed on the extruder 4. The tool holder in this embodiment is a three-cutter tool holder, the discharge aperture on the extruder die is 1mm, and the number of discharge holes on the extruder die is 6. When the pelletizing system is working, the pneumatic guide rod 9 pushes the working platform 2 to slide along the sliding guide rail 8, so that the cutter 15 is evenly forced to fit on the extruder die 3, and the servo motor 13 rotates to drive the cutter 15 on the tool holder 14 to perform pelletizing work, and the pressure of the pneumatic guide rod 9 is adjusted so that the rotating surface of the cutter is completely fitted with the die surface without material adhesion residue.

[0041] The temperature control system includes a heating jacket 22, an air inlet thermocouple 23, and an air outlet thermocouple 24. The heating jacket 22 is sleeved on the air supply channel 18, the air inlet thermocouple 23 is arranged at the connection between the air supply channel 18 and the pelletizing cover 19, and the air outlet thermocouple 24 is arranged at the connection between the pelletizing cover 19 and the discharge channel 21. The heating jacket 22 used in this embodiment is an electric heating jacket. When the temperature control system is working, the required ambient temperature is set, and the system adjusts the power of the heating jacket 22 according to the temperature of the air inlet thermocouple 23, so that the foaming environment in the pelletizing cover 19 is at a required constant temperature.

[0042] The working platform 2 also includes a control panel 5 and an equipment electrical box 6. The control panel 5 is provided with an equipment main switch, an emergency stop button, a heating switch, a temperature adjustment display, a motor switch, a speed adjustment knob, a speed display, a fan switch, and an air volume adjustment knob. The equipment is turned on and the working parameters are adjusted through the equipment electrical box and the control panel.

[0043] The base 1 is also provided with a storage bin 10 for collecting materials blown out from the discharge port.

[0044] Working principle: When the continuous extrusion polymer foam beads device is working, the extruder 4 first extrude uniform and stable foam wire through the extruder die 3, and then turn on the fan 16. Subsequently, the air pressure guide rod 9 pushes the working platform to slide along the sliding guide rail 8 until the cutter 15 is completely attached to the plane of the extruder die 3, and then start the servo motor 13, and drive the cutter 15 to rotate and cut pellets through the tool holder 14. Adjust the pressure of the air pressure guide rod 9 so that there will be no residual material adhesion between the cutter 15 surface and the extruder die 3. Observe the foam beads through the observation window 20, adjust the speed of the servo motor 13 until the length of the foam beads reaches the requirement, turn on the temperature control system to set the ambient temperature, if the foam beads are wrinkled and sandwiched, lower the set temperature, if the beads are low in multiples and the surface is cracked, increase the set temperature, use the air volume control valve 17 to adjust the air volume of the fan 16 until the temperature of the outlet thermocouple 24 is slightly greater than the temperature of the inlet thermocouple 23, and the foam beads can be blown out.

[0045] The utility model discloses a continuous extrusion polymer foaming bead device which can be used to produce polymer foaming beads such as plastics and rubber, including but not limited to polypropylene (PP), polystyrene (PS), polyethylene (PE), polybutylene (PB), polycarbonate (PC), acrylonitrile-styrene copolymer (AS), thermoplastic polyurethane elastomer (TPU), vinyl polymer grafted polyether polyol (POP), polymethyl methacrylate (PMMA), polylactic acid (PLA), polybutylene adipate / terephthalate (PBAT), polybutylene succinate (PBS) and recycled materials thereof.

[0046] Figure 4Schematic diagram of the apparent morphology of the beads obtained under different temperature control conditions in the continuous extrusion polymer foam beads device. Figure 4 -ⅰNot issued; Figure 4 -ⅱFull; Figure 4 -ⅲSandwich; Figure 4 -ⅳ Shrinkage.

[0047] It should be noted that the above embodiments are merely preferred embodiments of the present utility model and are not intended to limit the protection scope of the present utility model. Equivalent replacements or substitutions made on the basis of the above embodiments all fall within the protection scope of the present utility model.

Claims

1. A device for continuously extruding polymer foam beads, characterized in that: It comprises a base, a sliding guide rail arranged on the base, and a working platform movable along the sliding guide rail, wherein the working platform comprises an air supply system, a pelletizing system and a temperature control system; The air supply system includes a fan, an air supply channel, a pelletizing hood and an air outlet channel connected to the fan in sequence, the pelletizing hood is connected to the extruder so that the material extruded by the extruder enters the pelletizing hood; the air supply system is used to cool the material in the pelletizing hood and bring the material away from the die surface in time to the discharge port for collection; The pelletizing system comprises a driving motor, a knife holder connected to the driving motor and located in a pelletizing cover, and a cutter is fixed on the knife holder; the pelletizing system drives the knife holder and the cutter to rotate through the driving motor to cut the material extruded by the extruder into pellets; The temperature control system includes a heating jacket arranged on the air supply channel, an air inlet thermocouple arranged at the connection between the air supply channel and the pelletizing hood, and an air outlet thermocouple arranged at the connection between the pelletizing hood and the discharge channel; the temperature control system is used to adjust the foaming environment temperature in the pelletizing hood; By adjusting the speed of the driving motor in the pelletizing system, the length of the foamed beads is controlled, and the temperature of the foaming environment is adjusted by the temperature control system to obtain foamed beads that meet the requirements. The air volume is adjusted by the air supply system to blow the obtained foamed beads to the discharge port for collection.

2. The continuous extrusion polymer foam beads device according to claim 1, characterized in that: A transmission guide rod is arranged on the base, and the transmission guide rod is a pneumatic guide rod, a hydraulic guide rod or an electric guide rod.

3. The device for continuously extruding polymer foamed beads according to claim 2, characterized in that: A guide rail slider is provided on the sliding guide rail, and the guide rail slider is connected to the working platform. The guide rail slider drives the working platform to move along the sliding guide rail under the action of the transmission guide rod.

4. The device for continuously extruding polymer foamed beads according to claim 1, characterized in that: The air supply system comprises an air volume control valve for regulating the air supply volume, and the air volume control valve is arranged at the connection between the fan and the air supply channel.

5. The device for continuously extruding polymer foamed beads according to claim 1, characterized in that: Observation windows are arranged on both sides of the pelletizing cover for real-time observation of the pelletizing condition of the equipment.

6. The device for continuously extruding polymer foamed beads according to claim 1, characterized in that: The extruder is connected to an extruder die, the discharge hole diameter of the extruder die is 0.6-3mm, and the number of discharge holes is 2-20.

7. The device for continuously extruding polymer foamed beads according to claim 1, characterized in that: The knife holder is a 2-7 cutter knife holder.

8. The device for continuously extruding polymer foamed beads according to claim 1, characterized in that: The heating jacket is controlled by an electric heating jacket, an oil ring, a water ring or a heating wire.

9. The device for continuously extruding polymer foamed beads according to claim 1, characterized in that: A material storage bin is also provided on the base, and the material storage bin is used to collect the materials blown out from the discharge port.

10. The device for continuously extruding polymer foamed beads according to claim 1, characterized in that: The working platform also includes an equipment electrical box and a control panel, on which a main equipment switch, an emergency stop button, a heating switch, a temperature adjustment display, a motor switch, a speed adjustment knob, a speed display, a fan switch, and an air volume adjustment knob are provided.

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