A kind of injection band groove drainage structure and the cutting process using the structure

Abstract

The application discloses a kind of belonging to polymer material granulation technical field's injection band groove drainage structure and the cutting process using the structure, including injection band water tank, drainage net plate, drainage net plate is equipped with several large aperture drainage holes, drainage net plate is equipped with water control valve below drainage hole, water control valve can adjust the opening number and / or opening degree of drainage hole, overflow water and spray water can be discharged in full amount through drainage hole before entering cutting chamber, avoid a large amount of water flow with material bar gush into cutting chamber and collide with moving knife to form turbulent flow, while cooling water temperature is 20~28 ℃, both can reduce low-temperature hard material to cutting tool accelerated wear, also can reduce the bending deformation of high-temperature soft material, in addition, since front turbulent flow has been eliminated when strip is cut, strip keeps vertical stable posture in cantilever section, so that the particle end face after cutting is neat and length is consistent, so that long strip, toothpick material and oblique cutting etc. Special-shaped particles are eliminated at the same time, realize energy saving and consumption reduction and the extension of tool life.

Description

Technical Field

[0001] This invention relates to the field of polymer material granulation technology, specifically to a grooved drainage structure and a pelletizing process using the structure. Background Technology

[0002] Underwater pelletizers are widely used in the production of polymer materials such as PA6.

[0003] Chinese invention patent publication number "CN117261031A" discloses a water-flushing automatic pelletizing system, which includes a water-flushing feeding device, an underwater pelletizer, and a water filtration device. The water-flushing feeding device uses water flow to wash and transport resin strips, while the underwater pelletizer cuts the transported strips into pellets. However, although the feed plate of the above-mentioned water-flushing automatic pelletizing system is equipped with drainage holes, the hole diameter is too small, resulting in insufficient drainage capacity. This causes a large amount of overflow water and spray water to rush into the pelletizing chamber along with the strips. The water flow collides with the moving blade, creating violent turbulence. The strips are in a cantilevered state in the section from leaving the feed roller to entering the cutter, and are easily tilted and swayed laterally by the impact of turbulence. This prevents the moving blade from achieving vertical cutting, ultimately producing irregularly shaped particles such as long strips, toothpicks, and oblique cuts. This significantly reduces the yield rate of the finished product and can lead to uneven extraction and drying, blockage of the downstream feeding screen, and even blockage of the spinning screw inlet, causing unplanned downtime losses.

[0004] Furthermore, this water-flushing automatic pelletizing system has strict requirements for water temperature control, needing to be maintained within the range of 12–14℃. When the water temperature is too high, causing the feed strips to soften, irregularly shaped pellets are still easily produced; while when the water temperature is too low, causing the feed strips to harden, it will exacerbate the wear of the cutter. Neither of these conditions is conducive to normal pelletizing. However, this controlled temperature is usually lower than the ambient temperature, requiring a large amount of energy for cooling. Improvements are urgently needed to address these shortcomings. Summary of the Invention

[0005] The purpose of this invention is to provide a simple, low-cost, and stable injection groove drainage structure and a pelletizing process using this structure, so as to solve the above-mentioned problems existing in the prior art.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is: a tape injection groove drainage structure, including a tape injection groove and a drainage mesh plate, characterized in that: the drainage mesh plate has a plurality of large-diameter drainage holes, and a water control valve is provided below the drainage holes on the drainage mesh plate. The water control valve can adjust the number and / or degree of opening of the drainage holes. Cooling water is injected into one end of the tape injection groove relative to the drainage mesh plate. The tape moves through the tape injection groove to the drainage mesh plate, and the water can flow out through the opened drainage holes.

[0007] By adopting the above technical solution, the large-diameter drainage holes on the drainage screen, combined with the water control valve below, allow overflow water and spray water to be fully discharged through the drainage holes before entering the pelletizing chamber. This avoids a large amount of water flowing into the pelletizing chamber with the material strip and colliding with the moving blade to form turbulence. As a result, the material strip maintains a vertical and stable posture after leaving the feed roller and enters the cutting area. The moving blade can vertically cut the material strip to eliminate irregularly shaped particles such as long strips, toothpicks, and oblique cuts. At the same time, the water control valve can adjust the opening of the drainage holes on the drainage screen, thereby controlling the amount of cooling water entering the pelletizer and preventing excessive cooling water from entering the cooling chamber. This means that the pelletizing water temperature does not need to be strictly maintained in the low-temperature range of 12-14℃. Stable pelletizing quality can still be maintained at a higher water temperature of 20-28℃. This reduces the large amount of cooling energy consumed due to low-temperature cooling and avoids accelerated wear of the cutting blade caused by low-temperature hard materials. Thus, while improving the pelletizing qualification rate, it also achieves the effects of energy saving, consumption reduction, and extended blade life.

[0008] The above-mentioned drainage structure with a groove can be further configured such that the diameter of the drainage hole is 3mm to 5mm, and the distance between two adjacent drainage holes is 2mm to 4mm.

[0009] By adopting the above technical solution: after increasing the diameter of the drainage holes to 3mm to 5mm, the cross-sectional area of ​​a single hole for drainage is increased compared to the original 2mm diameter hole. The spacing between adjacent holes is maintained at 2mm to 4mm so that the hole distribution density meets the requirements for drainage uniformity. When the valve below the drainage mesh is fully open, the overflow water and spray water can be smoothly discharged through the drainage holes, avoiding water accumulation or backflow at the inlet of the pelletizing chamber. At the same time, it reduces the probability of the drainage holes being blocked by debris, reduces the frequency of downtime for cleaning due to poor drainage, and further improves the reliability and maintenance convenience of the injection groove drainage structure in continuous production.

[0010] Simultaneously, a pelletizing process employing a grooved drainage structure is disclosed, characterized by the following steps: S1: Adjust the drainage. Adjust the position of the valve plate in the water control valve relative to the drainage screen plate according to the ambient temperature and the material of the strip, and adjust the number of drainage holes that are open. S2: Cooling, several extruded strips are conveyed to the strip injection tank. The cooling device injects cooling water at 20~28℃ into the strip injection tank at the input end of the strip. The strip moves along the strip injection tank and is cooled by the cooling water in the strip injection tank. S3: Drainage feeding, cooling water flows out of the water tank through the drain hole, and the strip is clamped and transported to the pelletizing mechanism by the upper and lower feed rollers. S4: Pelletizing. The end of the strip moves to the fixed cutter of the pelletizing mechanism. The fixed cutter carries the strip, and the moving cutter rotates to cut the strip vertically to form pellets. The cut pellets fall into the pelletizing chamber.

[0011] By adopting the above technical solution: adjusting the valve plate position according to the ambient temperature and strip material to control the number of drainage holes opened, the cooling water volume entering the strip water tank and the drainage volume are dynamically matched, avoiding the formation of turbulence caused by insufficient drainage and a large amount of water flowing into the pelletizing chamber with the strip; cooling water at 20~28℃ cools the moving strip, which reduces cooling energy consumption compared to the traditional low temperature control of 12~14℃. At the same time, this temperature range keeps the strip at a suitable hardness, which not only avoids accelerated wear of the cutter by low-temperature hard materials, but also prevents bending deformation of high-temperature soft materials in the cantilever section due to their own weight or water flow disturbance. When the strip is clamped and transported to the fixed cutter by the upper and lower feed rollers, the strip maintains a vertical and stable posture in the cantilever section because the turbulence in front has been eliminated. When the moving cutter rotates, it can cut the strip vertically, making the cut pellets neat and of uniform length. Thus, while eliminating long strips, toothpick-shaped materials and oblique cuts, it achieves energy saving, consumption reduction and tool life extension.

[0012] The above pelletizing process can be further configured as follows: between steps S1 and S2, step S1.1 is also included: adjusting the distance between the moving cutter and the fixed cutter of the pelletizing mechanism to eliminate burrs on the end face of the slices.

[0013] By adopting the above technical solution: after the drainage volume is matched and the cooling water temperature is set, the gap between the moving cutter and the fixed cutter is adjusted according to the material of the strip and the target particle requirements, so that the blade distance is precisely controlled to a suitable range to eliminate burrs on the end face of the slice. Since the improvement of the drainage structure has eliminated the impact of turbulence on the cantilever section of the strip, the strip always maintains a vertical and stable posture when entering the cutting area. Even if the blade distance is adjusted to a smaller gap, toothpick material will not be generated. The precise control of the blade distance makes the shearing surface more neat, and the end face of the cut particles is smooth and burr-free. This avoids the blockage of subsequent conveying pipes or the problem of filament breakage in the downstream spinning process caused by burrs or tail material. At the same time, the neat cut surface reduces the dust generated by friction during the conveying process, thereby improving the pelleting quality and the stability of downstream processing while maintaining a high finished product qualification rate.

[0014] The above pelletizing process can be further configured such that the gap between the fixed cutter and the moving cutter is 3-6 μm.

[0015] By adopting the above technical solution, the gap between the fixed cutter and the moving cutter is controlled within the range of 3~6μm. This allows the blade gap to be flexibly adjusted within this range according to the material, hardness, and target particle length of the strip without replacing the cutter or significantly altering the equipment parameters. Simultaneously, because the drainage structure eliminates the impact of turbulence on the cantilever section of the strip, the strip maintains a vertical and stable posture when entering the cutting area. Even with adjustments within a relatively wide gap range of 3~6μm, the cut particle ends remain neat and of consistent length, avoiding the phenomenon of toothpick-like material due to excessively small gaps and tail material due to excessively large gaps. Furthermore, precise gap control ensures a pure shearing effect, reducing burrs or adhesion at the particle tails caused by insufficient shearing. This achieves flexible switching of particle sizes while ensuring consistent particle quality and reducing the risk of material blockage and dust problems in subsequent processes due to uneven particle size or tail detachment.

[0016] The above pelletizing process can be further configured such that the cooling water temperature in step S2 is preferably 25°C.

[0017] By adopting the above technical solution, the cooling water temperature is set to 25℃. At this temperature, the strip maintains a moderate hardness, which prevents it from bending and deforming in the cantilever section due to gravity or residual water flow if it is too soft, and also prevents excessive wear on the cutter due to excessive hardness. At the same time, the water temperature of 25℃ significantly reduces the cooling capacity required by the refrigeration equipment compared to the traditional low temperature control of 12~14℃, thus reducing the energy cost of the pelletizing process. In addition, combined with the drainage structure's function of eliminating turbulence, the strip can still maintain a vertical and stable posture when entering the cutting area at this water temperature. Therefore, the dual effects of energy saving and consumption reduction and extending the tool life are achieved without affecting the pelletizing quality.

[0018] The above pelletizing process can be further configured such that the water control valve closes the drain hole, and cooling water can flow into the pelletizing chamber from the side of the lower feed roller near the drain mesh plate to the other side through the gap between the strips.

[0019] By adopting the above technical solution: when the water control valve closes the drain hole, the cooling water can still flow along the gap between the strips through the lower feed roller near the drain screen towards the pelletizing chamber. Under the controlled drainage state, it provides continuous water cooling support for the strip, avoiding overheating or surface adhesion of the strip due to complete water cut-off. At the same time, a small amount of cooling water forms an auxiliary lubrication and cooling effect in the cutting area, reducing the risk of dry friction between the cutting blade and the strip. Thus, the strip injection groove drainage structure can still maintain the temperature stability and cutting blade operation reliability during the strip pelletizing process under different drainage conditions.

[0020] The beneficial effects of this invention are as follows: First, the grooved drainage structure, by opening large-diameter drainage holes on the drainage mesh plate and cooperating with the water control valve, ensures that overflow water and spray water are fully discharged before entering the pelleting chamber. This effectively avoids a large amount of water flowing into the pelleting chamber with the material strip and colliding with the moving blade to form turbulence. As a result, the material strip maintains a vertical and stable posture after leaving the feed roller and enters the cutting area for vertical cutting, eliminating irregularly shaped particles such as long strips, toothpicks, and oblique cuts. The valve plate and valve body slide together and are pushed axially by the water control drive to adjust the drainage opening in real time. This means that the pelleting water temperature does not need to be strictly maintained in the low temperature range of 12-14℃. Stable pelleting quality can still be maintained at a higher water temperature of 20-28℃. This improves the finished product qualification rate while reducing low-temperature cooling energy consumption and avoiding accelerated wear of the cutting blade by low-temperature hard materials, achieving the effects of energy saving, consumption reduction, and extended tool life.

[0021] Secondly, the pelletizing process using a grooved drainage structure adjusts the valve plate position according to the ambient temperature and strip material to control the dynamic matching of drainage and cooling water volume. This ensures that the cooling water at 20~28℃ maintains the strip's appropriate hardness during the cooling process, preventing wear on the cutter from low-temperature hard materials and bending deformation from high-temperature soft materials. It also eliminates turbulence at the front end, keeping the strip vertically stable in the cantilever section to ensure that the pellet end face is neat and of consistent length when the moving cutter cuts vertically. Combined with step S1.1, which adjusts the gap between the moving and fixed cutters according to the target pellet length to quickly switch pellet specifications without changing the cutter, and the fact that the cooling water still flows along the strip gap towards the pelletizing chamber when the water control valve is closed to provide auxiliary lubrication and cooling, this process eliminates irregularly shaped pellets while achieving flexible switching of pellet specifications, energy saving, and extended tool life.

[0022] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the grooved drainage structure of the present invention; Figure 2 For the present invention Figure 1 Schematic diagram of part A in the middle; Figure 3 This is a schematic diagram of the combination of the upper feed roller and the lower feed roller of the present invention; Figure 4 This is a schematic diagram showing the distribution of drainage holes on the drainage mesh plate of the present invention; Figure 5 This is a schematic diagram of the pelletizing process using a grooved drainage structure according to the present invention. Figure 6 This is a schematic diagram of cooling water turbulence. Figure 7 This is a schematic diagram illustrating the effect of the pelletizing process using the grooved drainage structure of the present invention; Label annotations: 1. Water tank; 2. Drainage mesh plate; 21. Drainage hole; 3. Water control valve; 4. Upper feed roller; 5. Lower feed roller; 6. Fixed cutter; 7. Moving cutter; 8. Strip. Detailed Implementation

[0024] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0025] This application provides a grooved drainage structure, such as... Figures 1 to 4 As shown, it includes a water injection tank 1 and a drainage mesh plate 2. The drainage mesh plate 2 has a plurality of large-diameter drainage holes 21. The drainage mesh plate 2 is provided with a water control valve 3 below the drainage holes 21. The water control valve 3 can adjust the number and / or degree of opening of the drainage holes 21. Cooling water is injected into one end of the water injection tank 1 relative to the drainage mesh plate 2. The strip 8 moves through the water injection tank 1 to the drainage mesh plate 2, and the water can flow out through the opened drainage holes 21.

[0026] The diameter of the drainage hole 21 is 3mm to 5mm, and the distance between two adjacent drainage holes 21 is 2mm to 4mm.

[0027] The water control valve 3 includes a valve body, a valve plate, and a water control drive component. The water control drive component is detachably connected to the valve body. The valve plate is linked to the output end of the water control drive component. The valve plate is slidably engaged with the valve body. The water control drive component drives the valve plate to move axially along the valve body, causing the valve plate to open or close the drain hole 21.

[0028] It should be noted that the water control valve 3 can also be a ball valve or other similar valves, which can control the water output and thus adjust the drainage volume of the drain hole.

[0029] This application also provides a pelletizing process using a grooved drainage structure, such as... Figure 5 As shown, it includes the following steps: S1: Adjust the drainage. Adjust the position of the valve plate in the water control valve 3 relative to the drainage mesh plate 2 according to the ambient temperature and the material of the strip, and adjust the number of opening holes 21. S1.1: Adjust the pelletizing process by adjusting the distance between the moving cutter 7 and the fixed cutter 6 of the pelletizing mechanism to eliminate burrs on the end face of the slices; S2: Cooling, several extruded strips 8 are conveyed to the strip water tank 1. The cooling device injects cooling water at 20~28℃ into the strip water tank 1 at the input end of the strip 8. The strip 8 moves along the strip water tank 1 and is cooled by the cooling water in the strip water tank 1. S3: Drainage feeding, cooling water flows out of the water tank 1 through the drain hole 21, and the strip 8 is clamped and transported to the pelletizing mechanism by the upper feed roller 4 and the lower feed roller 5. S4: Pelletizing. The end of the strip 8 moves to the fixed cutter 6 of the pelletizing mechanism. The fixed cutter 6 carries the strip 8, and the moving cutter 7 rotates and vertically cuts the strip 8 to form several pellets. The cut pellets fall into the pelletizing chamber.

[0030] In step S2, the preferred cooling water temperature is 25°C.

[0031] The water control valve 3 closes the drain hole 21, allowing cooling water to flow from the side of the lower feed roller 5 near the drain mesh plate 2 to the other side through the gap between the strips 8 into the pelletizing chamber.

[0032] Example 1: S1: Adjust drainage. Adjust the position of the valve plate in the water control valve 3 relative to the drainage mesh plate 2 according to the ambient temperature and the material of the strip, and adjust the number of opening holes 21. S1.1: Adjust the pelletizing process by adjusting the distance between the moving cutter 7 and the fixed cutter 6 of the pelletizing mechanism to eliminate burrs on the end face of the slices; S2: Cooling, several PA6 strips 8 extruded and conveyed to the water injection tank 1. The cooling device injects 25°C cooling water into the water injection tank 1 at the input end of the strip 8. The strip 8 moves along the water injection tank 1 and is cooled by the cooling water in the water injection tank 1. S3: Drainage feeding, cooling water flows out of the water tank 1 through the drain hole 21, and the strip 8 is clamped and transported to the pelletizing mechanism by the upper feed roller 4 and the lower feed roller 5. S4: Pelletizing. The end of the strip 8 moves to the fixed cutter 6 of the pelletizing mechanism. The fixed cutter 6 carries the strip 8, and the moving cutter 7 rotates and vertically cuts the strip 8 to form several pellets. The cut pellets fall into the pelletizing chamber.

[0033] Example 2: S1: Adjust drainage. Adjust the position of the valve plate in the water control valve 3 relative to the drainage mesh plate 2 according to the ambient temperature and the material of the strip, and adjust the number of opening holes 21. S1.1: Adjust the distance between the moving cutter 7 and the fixed cutter 6 of the pelletizing mechanism to eliminate burrs on the end face of the slices; S2: Cooling, several extruded PET strips 8 are conveyed to the water injection tank 1. The cooling device injects 20°C cooling water into the water injection tank 1 at the input end of the strip 8. The strip 8 moves along the water injection tank 1 and is cooled by the cooling water in the water injection tank 1. S3: Drainage feeding, cooling water flows out of the water tank 1 through the drain hole 21, and the strip 8 is clamped and transported to the pelletizing mechanism by the upper feed roller 4 and the lower feed roller 5. S4: Pelletizing. The end of the strip 8 moves to the fixed cutter 6 of the pelletizing mechanism. The fixed cutter 6 carries the strip 8, and the moving cutter 7 rotates and vertically cuts the strip 8 to form several pellets. The cut pellets fall into the pelletizing chamber.

[0034] Example 3: S1: Adjust drainage. Adjust the position of the valve plate in the water control valve 3 relative to the drainage mesh plate 2 according to the ambient temperature and the material of the strip, and adjust the number of opening holes 21. S1.1: Adjust the distance between the moving cutter 7 and the fixed cutter 6 of the pelletizing mechanism to eliminate burrs on the end face of the slices; S2: Cooling, several extruded PBT strips 8 are conveyed to the strip injection tank 1. The cooling device injects 28°C cooling water into the strip injection tank 1 at the input end of the strip 8. The strip 8 moves along the strip injection tank 1 and is cooled by the cooling water in the strip injection tank 1. S3: Drainage feeding, cooling water flows out of the water tank 1 through the drain hole 21, and the strip 8 is clamped and transported to the pelletizing mechanism by the upper feed roller 4 and the lower feed roller 5. S4: Pelletizing. The end of the strip 8 moves to the fixed cutter 6 of the pelletizing mechanism. The fixed cutter 6 carries the strip 8, and the moving cutter 7 rotates and vertically cuts the strip 8 to form several pellets. The cut pellets fall into the pelletizing chamber.

[0035] Comparative Example 1: A pelletizing process includes the following steps: S1: Several PA6 strips 8 extruded and molded are conveyed to the water injection tank 1. The cooling device injects 16°C cooling water into the water injection tank 1 at the input end of the strip 8. The strip 8 moves along the water injection tank 1 and is cooled by the cooling water in the water injection tank 1. S2: Part of the cooling water flows out of the water tank 1 through the drain hole 21, and the other part of the cooling water flows into the pelletizing chamber through the gap between the strips 8. The strips 8 are clamped and transported to the pelletizing mechanism by the upper feed roller 4 and the lower feed roller 5. S3: The end of the strip 8 moves to the fixed cutter 6 of the pelletizing mechanism. The fixed cutter 6 carries the strip 8, and the moving cutter 7 rotates and vertically cuts the strip 8 to form pellets. The cut pellets fall into the pelletizing chamber.

[0036] Comparative Example 2: A pelletizing process includes the following steps: S1: Several extruded PBT strips 8 are conveyed to the strip injection tank 1. The cooling device injects 14°C cooling water into the strip injection tank 1 at the input end of the strip 8. The strip 8 moves along the strip injection tank 1 and is cooled by the cooling water in the strip injection tank 1. S2: Part of the cooling water flows out of the water tank 1 through the drain hole 21, and the other part of the cooling water flows into the pelletizing chamber through the gap between the strips 8. The strips 8 are clamped and transported to the pelletizing mechanism by the upper feed roller 4 and the lower feed roller 5. S3: The end of the strip 8 moves to the fixed cutter 6 of the pelletizing mechanism. The fixed cutter 6 carries the strip 8, and the moving cutter 7 rotates and vertically cuts the strip 8 to form pellets. The cut pellets fall into the pelletizing chamber.

[0037] The particles produced by the above embodiments and comparative embodiments over a period of time were tested, and the proportions of long particles, toothpick particles, oblique particles, and normal particles in the total particles were calculated.

[0038] Table 1. Detection results of Examples 1-3 and Control Examples 1-2 Example 1 ≤0.4% ≤0.2% ≤0.3% ≥99.1% Example 2 ≤0.2% ≤0.2% ≤0.2% ≥99.4% Example 3 ≤0.4% ≤0.3% ≤0.4% ≥98.9% Comparative Example 1 ≤3.5% ≤4.0% ≤4.5% ≥88.0% Comparative Example 2 ≤4.2% ≤4.8% ≤5.0% ≥86.0% Compared with the pelletizing process of the control embodiment, the pelletizing processes of the above embodiments have the following advantages: 1) By opening large-diameter drainage holes 21 on the drainage mesh plate 2 and configuring water control valve 3, the overflow water and spray water are discharged in full through the drainage holes 21 before entering the pelletizing chamber, which effectively eliminates the water flow turbulence in the pelletizing chamber. This allows the strip to maintain a vertical and stable posture after the feeding roller and enter between the moving cutter and the fixed cutter, achieving pure shearing and vertical cutting. This eliminates irregularly shaped particles such as long strips, toothpick materials and oblique cuts, and the finished product has no irregularly shaped particles. 2) Since the impact of turbulence on the strip is eliminated, the blade gap does not need to be widened due to the influence of water flow. The gap can be adjusted to be smaller, making the shearing purer, the cut surface neater and without trailing tail. The sharpening interval is extended, the blade life is significantly extended, and the sharpening cost and the frequency of downtime for blade replacement are reduced. 3) The improved drainage structure eliminates the risk of lateral swaying of the high-temperature soft strip at the end of the strip due to turbulence. The pelletizing water temperature can be increased from 12~14℃, which is strictly controlled by traditional processes, to 20~28℃ (preferably 25℃). After the strip softens, the blade wear is greatly reduced. At the same time, for every 12℃ increase in water temperature, 490KW of cooling capacity is saved at a production capacity of 35 tons / hour, and the energy saving effect is obvious. 4) The water flow fluctuation during online filter switching only affects the front section of the injection trough. Since the drainage screen has discharged all the overflow water, the fluctuation will not affect the movement of the strip behind the screen. The pelletizing process is not disturbed and no long strips will be generated due to the switching operation. 5) The finished product without irregularly shaped particles eliminates the problems of downstream feeding screen blockage and spinning screw feed port blockage, avoids unplanned downtime losses caused by material blockage, and improves the continuous operation stability of subsequent processes; 6) It only requires enlarging the original 2mm drainage hole 21 to 3~5mm and configuring a water control valve 3. The structural changes are small and the modification cost is low. It is also suitable for underwater pelletizing of various polymer materials such as PA6, PA66, PET, PBT, and PP, and has strong versatility.

[0039] The embodiments described above are merely examples of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements all fall within the scope of protection of the present invention.

Claims

1. A drainage structure with a water inlet groove, comprising a water inlet groove and a drainage mesh plate, characterized in that: The drainage mesh plate has several large-diameter drainage holes. The drainage mesh plate is equipped with a water control valve below the drainage holes. The water control valve can adjust the number and / or degree of opening of the drainage holes. Cooling water is injected into the water injection tank at one end relative to the drainage mesh plate. The strip moves to the drainage mesh plate through the water injection tank, and the water can flow out through the opened drainage holes.

2. The drainage structure with groove according to claim 1, characterized in that: The diameter of the drainage hole is 3mm to 5mm, and the distance between two adjacent drainage holes is 2mm to 4mm.

3. A pelletizing process employing the injection groove drainage structure as described in claims 1 to 2, characterized in that: Includes the following steps: S1: Adjust the drainage. Adjust the position of the valve plate in the water control valve relative to the drainage screen plate according to the ambient temperature and the material of the strip, and adjust the number of drainage holes that are open. S2: Cooling, several extruded strips are conveyed to the strip injection tank. The cooling device injects cooling water at 20~28℃ into the strip injection tank at the input end of the strip. The strip moves along the strip injection tank and is cooled by the cooling water in the strip injection tank. S3: Drainage feeding, cooling water flows out of the water tank through the drain hole, and the strip is clamped and transported to the pelletizing mechanism by the upper and lower feed rollers. S4: Pelletizing. The end of the strip moves to the fixed cutter of the pelletizing mechanism. The fixed cutter carries the strip, and the moving cutter rotates to cut the strip vertically to form pellets. The cut pellets fall into the pelletizing chamber.

4. The pelletizing process according to claim 3, characterized in that: The step between steps S1 and S2 also includes step S1.1: adjusting the distance between the moving cutter and the fixed cutter of the pelletizing mechanism to eliminate burrs on the end face of the slices.

5. The pelletizing process according to claim 4, characterized in that: The gap between the fixed cutter and the moving cutter is 3-6 μm.

6. The pelletizing process according to claim 3, characterized in that: In step S2, the preferred cooling water temperature is 25°C.

7. The pelletizing process according to claim 6, characterized in that: The water control valve closes the drain hole, allowing cooling water to flow from the side of the lower feed roller near the drain screen plate to the other side into the pelletizing chamber through the gap between the strips.

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