Pelletizing device of double-screw extruder for laboratory

Abstract

The utility model relates to the field of plastic color master batch production, in particular to a granulating device of a double-screw extruder for a laboratory. The twin-screw extruder granulation device for the laboratory at least comprises a cooling system, and the cooling system comprises an air cooling module arranged at an outlet of a mold and a water cooling module arranged behind the air cooling module; the air cooling module is used for preliminarily cooling the material strips, and the water cooling module is used for further cooling the material strips. According to the utility model, the advantages of air cooling and water cooling can be combined, the initial section uses air cooling to prevent materials from being cooled too fast, and the rear section uses water cooling to improve the cooling efficiency, so that resin sensitive to a water cooling medium can be uniformly cooled, the problems of sample bridging phenomenon and color master batch hollow phenomenon can be prevented, and the quality of extruded color master batch is ensured.

Description

Technical Field

[0001] The utility model relates to the field of plastic masterbatch production, in particular to a laboratory twin-screw extruder granulation device. Background Art

[0002] The laboratory twin-screw extruder has a simple structure, is very practical, has low production costs, improves labor efficiency, and has a wide range of applications. It is often used in the production of plastic masterbatches such as PP, PE, and PVC.

[0003] The working principle of the laboratory twin-screw extruder granulation device mainly involves the melting, mixing, molding and cooling process of plastic materials. Figure 1 As shown, the extruder typically includes a twin-screw extruder A, a traction device (not shown), a cooling device B, and a pelletizer C. The twin-screw extruder consists of two intermeshing screws mounted within a heated cylindrical barrel. During processing, solid plastic pellets are fed into the extruder's feed port. As the screws rotate, the material is propelled forward within the barrel, experiencing intense shearing and mixing, which uniformly disperses ingredients such as additives, fillers, or pigments. The melted and mixed plastic material passes through a mold (also known as a die head) into a specific shape, such as a strip or sheet. The shaped plastic material (e.g., a strip) is then fed into a cooling zone under the action of the traction device. Here, a cooling system (e.g., a water cooling system) rapidly reduces the temperature of the plastic material. The cooled and solidified plastic material is then fed into a pelletizer for pelletization. The pelletizer cuts the continuous material strands into uniform pellets, which can then be used for further processing or as a final product. This approach is used, for example, in the utility model patent publication No. CN215825928U.

[0004] Currently, thermoplastic resins and plastics are primarily used for laboratory performance research. The key characteristic of thermoplastic resins is that they are organic polymers with linear or branched structures. They soften upon heating and harden upon cooling, remaining chemically inert and maintaining this property regardless of repeated heating and cooling cycles. However, existing equipment for laboratory use has several drawbacks regarding the stability of masterbatch extrusion experiments. Resins sensitive to water cooling media, such as polycarbonate (PC), are susceptible to hydrolysis at high temperatures and absorb moisture during the water cooling process. Direct water-cooling and blow-drying can easily cause the material strands to cool too low, resulting in a surface that becomes sticky enough to cause different strands to adhere together, creating a so-called "bridging phenomenon." This can prevent the strands from flowing smoothly through the puller, potentially blocking or damaging the equipment, and in severe cases, even causing production interruptions. Furthermore, rapid cooling can cause the particle surface to solidify quickly while the interior remains incompletely solidified, resulting in hollow particles that can affect product performance.

[0005] The utility model patent with authorization announcement number CN202702434U provides an air-cooling system, which includes an extrusion granulation system, a first blower, a feed pipe, a second blower, a hopper, a conveying pipe, a cooling silo, a collection silo, a control valve, and a metering device. The extrusion granulation system is connected to the hopper, which is connected to the cooling silo via a feed pipe, and the cooling silo is connected to the collection silo via a feed pipe. A control valve is installed at the bottom of the collection silo; a metering device is installed below the collection silo; a first blower is installed on the feed pipe; and a second blower is installed on the conveying pipe. This cooling method has a slow cooling rate, and materials tend to accumulate easily, which may require multiple cooling cycles. Based on this, the existing technology still needs improvement. Utility Model Content

[0006] In view of this, the utility model provides a laboratory twin-screw extruder granulation device, which can at least solve the problems that the existing extruder granulation device is difficult to achieve uniform cooling of resins that are sensitive to water cooling media, and has a slow cooling speed.

[0007] The utility model discloses a laboratory twin-screw extruder granulating device, which at least comprises a cooling system. The cooling system comprises an air cooling module arranged at a die outlet and a water cooling module arranged behind the air cooling module. The air cooling module is used for initially cooling the material strips, and the water cooling module is used for further cooling the material strips.

[0008] In some embodiments, the air cooling module includes a plurality of fans arranged in a row along the moving direction of the material strip.

[0009] In some embodiments, the air cooling module is an air injection system, and the air injection system includes a plurality of air nozzles for injecting air toward the material strip.

[0010] In some embodiments, the water cooling module includes a water trough filled with cooling water, and the material strip passes through the cooling water in the water trough under the guidance of the traction device.

[0011] In some embodiments, the water cooling module is a spray system; the spray system includes a plurality of water spray nozzles that spray cooling water toward the material strip.

[0012] In some embodiments, the air cooling module includes an air shield disposed opposite to the exhaust side of the plurality of fans.

[0013] In some embodiments, the spray system further comprises a water collection tank located below the plurality of water spray nozzles and the material strip.

[0014] In some embodiments, the air cooling module further includes a cooling water circulation device, which is disposed between the water collecting tank and the spraying system and is used to circulate the cooling water collected in the water collecting tank to the spraying system.

[0015] In some embodiments, the laboratory twin-screw extruder granulation device further includes a dehydration device, which is disposed between the water cooling module and the pelletizer and is used to dehydrate and dry the material strips.

[0016] In some embodiments, the laboratory twin-screw extruder granulation device further includes a control device, which is electrically connected to the air cooling module and the water cooling module for controlling the start and stop of the air cooling module and the water cooling module.

[0017] The beneficial effects of this utility model include combining the advantages of air and water cooling, using air cooling in the initial stage to prevent over-rapid cooling of the material, and water cooling in the final stage to improve cooling efficiency. This not only ensures uniform cooling of resins sensitive to water cooling media, but also prevents sample bridging and hollow masterbatch formation, thereby ensuring the quality of extruded masterbatch. The modular design of the cooling system ensures that the material is cooled at the appropriate temperature, avoiding material stress and deformation, and facilitating adjustment and optimization based on different material properties. The air and water cooling modules can be activated or deactivated according to the properties of the material strip, providing a wide range of applications. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other embodiments can be obtained based on these drawings without paying any creative work.

[0019] Figure 1 This is a simplified structural diagram of a twin-screw extruder granulation device commonly used in the prior art;

[0020] Figure 2 The utility model provides a structural schematic diagram of a laboratory twin-screw extruder granulation device.

[0021] Description of reference numerals:

[0022] 1. Twin-screw extruder; 2. Material bar; 3. Fan; 4. Wind deflector; 5. Water collecting trough; 6. Water nozzle; 7. Dehydration device; 8. Pelletizer; 9. Traction device. DETAILED DESCRIPTION

[0023] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the embodiments of the present invention are further described in detail below in combination with specific embodiments and with reference to the accompanying drawings.

[0024] It should be understood that the embodiments of the present invention shown in the exemplary embodiments are merely illustrative. Although only a few embodiments are described in detail in the present invention, it is readily apparent to those skilled in the art that various modifications are possible without departing substantially from the teachings of the present invention. Accordingly, all such modifications are intended to be included within the scope of the present invention. Other substitutions, modifications, variations, and deletions may be made to the design, operating conditions, and parameters of the following exemplary embodiments without departing from the spirit of the present invention.

[0025] The utility model provides a laboratory twin-screw extruder granulation device, which at least includes a cooling system. The cooling system includes an air cooling module arranged at the mold outlet of the twin-screw extruder 1, and a water cooling module arranged after the air cooling module; the air cooling module is used to initially cool the material strip 2, and the water cooling module is used to further cool the material strip 2.

[0026] This utility model combines the advantages of air and water cooling, using air cooling in the initial stage to prevent over-rapid cooling of the material, and water cooling in the final stage to improve cooling efficiency. This ensures uniform cooling of resins sensitive to water-cooling media while preventing sample bridging and hollow masterbatch formation, thereby ensuring the quality of extruded masterbatch. The modular design of the cooling system ensures that the material strip 2 cools at the appropriate temperature, avoiding material stress and deformation, and facilitating adjustment and optimization based on different material properties. The air and water cooling modules can be activated or deactivated based on the properties of the material strip 2, ensuring a wide range of applications.

[0027] In some embodiments, the material strip 2 is driven by the traction device 9 to move toward the pelletizer 8. The air cooling module includes multiple fans 3 arranged in a row along the moving direction of the material strip 2. The multiple fans 3 work together to cool the material strip 2 quickly and evenly.

[0028] In some embodiments, the air cooling module is an air injection system comprising multiple air nozzles directed toward the material strip 2. The air nozzles are arranged along the direction of movement of the material strip 2 and are responsible for injecting cooling gas at high speed onto the target surface. Depending on the application requirements, the air nozzles can be linear with a single aperture or a multi-aperture atomized spray, with atomized spray being preferred.

[0029] In some embodiments, the water-cooling module includes a trough filled with cooling water, and the material strip 2 is cooled by the cooling water in the trough under the guidance of the traction device 9. Since the material strip 2 has already been cooled by the air-cooling module, the use of direct cooling water here will not cause the temperature of the material strip 2 to be too low, which would cause bridging and hollowing of the masterbatch, thereby ensuring the quality of the extruded masterbatch.

[0030] In some embodiments, the water cooling module is a spray system comprising multiple nozzles 6 that spray cooling water toward the material strip 2. These nozzles 6 are arranged along the direction of movement of the material strip 2 and are responsible for spraying the cooling water at high speed onto the target surface, further cooling the material strip 2. This spray system configuration conserves water and allows for controllable cooling water temperature and spray rate, making it easy to adjust as needed.

[0031] In some embodiments, the air cooling module further includes a windshield 4 arranged opposite to the exhaust side of the plurality of fans 3. The number of windshields 4 can be set to be the same as the number of fans 3, or only one can be set. When only one is set, the windshield 4 is arranged opposite to the exhaust port of each fan 3. The setting of the windshield 4 can effectively block part of the hot air from directly flowing back to the suction side of the fan 3, thereby reducing the circulation of heat inside the system and improving the overall cooling effect. In addition, the windshield 4 can reduce the airflow turbulence near the exhaust port of the fan 3, thereby reducing the noise caused by air turbulence. When there is only one windshield 4, it also helps to balance the airflow discharged from the plurality of fans 3, directing the concentrated airflow to a wider area, increasing the heat dissipation area and coverage, ensuring the consistency of the airflow distribution of the entire cooling system, and improving the heat dissipation efficiency.

[0032] In some embodiments, the spraying system further includes a water collection tank 5, which is located below the multiple water nozzles 6 and the material strip 2. The water collection tank 5 is used to collect cooling water dripping from the material strip 2, causing water waste.

[0033] In some embodiments, the air cooling module also includes a cooling water circulation device (not shown in the figure), which is arranged between the water collection tank 5 and the spray system, and is used to circulate the cooling water collected in the water collection tank 5 to the spray system, and recycle the cooling water collected during the cooling process to reduce water resource consumption.

[0034] In some embodiments, the laboratory twin-screw extruder granulation device also includes a dehydration device 7, which is arranged between the water-cooling module and the pelletizer 8, and is used to dehydrate and dry the material strips 2. Specifically, according to the required dehydration effect and the characteristics of the plastic material, a suitable dehydration device is selected. Common dehydration equipment includes: Centrifugal dehydrator: The centrifugal force generated by high-speed rotation is used to throw water out of the material strips 2. Drying and conveying system: Combines air flow and heat source to simultaneously convey and dry the material strips 2. Vibrating screening machine with hot air drying: While vibrating and screening, hot air is blown to the material strips 2 to achieve a drying effect. This is a prior art, so it will not be repeated here.

[0035] In some embodiments, the laboratory twin-screw extruder pelletizing apparatus further includes a control device electrically connected to the air cooling module and the water cooling module for controlling the activation and deactivation of the air cooling module and the water cooling module, thereby facilitating adjustment and optimization based on different material properties. Specifically, the air cooling module and the water cooling module can be activated or deactivated based on the properties of the material, making the cooling process more flexible and diverse.

[0036] In some embodiments, the laboratory twin-screw extruder pelletizing apparatus further includes a control device electrically connected to the air cooling module and the water cooling module for controlling the activation and deactivation of the air cooling module and the water cooling module, thereby facilitating adjustment and optimization based on different material properties. Specifically, the air cooling module and the water cooling module can be activated or deactivated based on the properties of the material, making the cooling process more flexible and diverse.

[0037] The technical features of the above embodiments can be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0038] The above-described embodiments merely represent several implementation methods of the present application. While the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the utility model patent. It should be noted that a person skilled in the art could make various modifications and improvements without departing from the spirit of the present application, all of which fall within the scope of protection of the present application. Therefore, the scope of protection of the present patent application shall be determined by the appended claims.

Claims

1. A laboratory twin-screw extruder granulation device, characterized in that, At least a cooling system is included, the cooling system comprising an air cooling module arranged at the mold outlet, and a water cooling module arranged after the air cooling module; the air cooling module is used to initially cool the material strip (2), and the water cooling module is used to further cool the material strip (2).

2. The laboratory twin-screw extruder granulation device according to claim 1, characterized in that, The air cooling module comprises a plurality of fans (3) arranged in a row along the moving direction of the material strip (2).

3. The laboratory twin-screw extruder granulation device according to claim 1, characterized in that, The air cooling module is an air injection system, and the air injection system comprises a plurality of air nozzles for injecting air toward the material strip (2).

4. The laboratory twin-screw extruder granulation device according to claim 1, characterized in that, The water cooling module comprises a water trough filled with cooling water, and the material strip (2) passes through the cooling water in the water trough under the guidance of the traction device (9).

5. The laboratory twin-screw extruder granulation device according to claim 1, characterized in that, The water cooling module is a spray system; the spray system comprises a plurality of water spray nozzles (6) for spraying cooling water toward the material strip (2).

6. The laboratory twin-screw extruder granulation device according to claim 2, characterized in that, The air cooling module comprises a wind shield (4) arranged opposite to the exhaust side of the plurality of fans (3).

7. The laboratory twin-screw extruder granulation device according to claim 5, characterized in that, The spraying system further comprises a water collecting trough (5), wherein the water collecting trough (5) is located below the plurality of water spray nozzles (6) and the material strip (2).

8. The laboratory twin-screw extruder granulation device according to claim 7, characterized in that, The air cooling module further comprises a cooling water circulation device, which is arranged between the water collecting tank (5) and the spraying system and is used for circulating the cooling water collected by the water collecting tank (5) to the spraying system.

9. The laboratory twin-screw extruder granulation device according to claim 1, characterized in that, It also includes a dehydration device (7), which is arranged between the water cooling module and the pelletizer (8) and is used to dehydrate and dry the material strips (2).

10. The laboratory twin-screw extruder granulation device according to claim 1, characterized in that: It also includes a control device, which is electrically connected to the air cooling module and the water cooling module and is used to control the start and stop of the air cooling module and the water cooling module.

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