Stretched pvdc film setting device

Abstract

This application relates to the field of polymer material processing technology, and in particular to a stretching PVDC film shaping equipment, which includes a support frame, a feed pipe at the top of the support frame, a cooling and shaping component at the top of the feed pipe, and a film body at the top of the cooling and shaping component. This application utilizes components such as a cooling air regulating pipe, cooling holes, a servo motor, and a lead screw. The servo motor drives the lead screw in a threaded transmission engagement with an internal threaded block, enabling the internal threaded block to move linearly along the limiting groove of the cooling air regulating pipe. Furthermore, by adjusting the area of ​​the internal threaded block blocking the cooling holes, precise control of the cooling air flow rate is achieved. The 30° inclined cooling hole design, combined with an equidistant array layout, allows the cooling air to act uniformly on the inner wall of the film body in a spiral airflow, effectively avoiding the temperature gradient difference problem caused by traditional direct-blowing cooling. Thus, this device can achieve the effect of uniformly cooling and shaping films of different thicknesses by dynamically adjusting the cooling air flow rate.

Description

Technical Field

[0001] This application relates to the field of polymer material processing technology, and in particular to stretching PVDC film shaping equipment. Background Technology

[0002] Traditional PVDC film shaping methods mainly rely on simple air cooling or water cooling technologies. While air cooling has lower equipment costs, it is inefficient and makes precise control of the film cooling process difficult. Uneven cooling easily leads to stress concentration within the film, resulting in significant defects in thickness uniformity, optical properties, and mechanical strength. During subsequent processing and use, these defects can easily cause cracking and wrinkling, severely impacting product quality and lifespan.

[0003] While water cooling technology improves cooling speed, it suffers from the drawback of direct contact between the cooling medium and the film. This can lead to water contamination on the film surface, reducing its hygiene performance and making it unsuitable for packaging applications with stringent hygiene requirements, such as food and pharmaceuticals. Furthermore, the uneven temperature distribution of the cooling medium and the impact of water flow during cooling make it difficult to ensure uniform cooling, resulting in inconsistent film quality. As market demands for PVDC film quality continue to rise, especially in high-end food packaging and medical device packaging, more stringent standards are being imposed on film thickness accuracy, barrier properties, and consistency of mechanical properties. Existing film forming equipment and processes are no longer sufficient to meet these growing needs.

[0004] Regarding the aforementioned technologies, the inventors have discovered the following drawbacks: Existing devices mostly employ vertical or unidirectional cooling hole designs, lacking inclined angles and circumferential array arrangements. This results in insufficient cooling air coverage of the entire circumference of the film and concentrated local wind speeds, easily causing uneven film thickness or surface wrinkles. Cooling air flow is often adjusted by fixing the hole diameter or using valves, making it impossible to precisely control the cooling intensity for films of different thicknesses. Especially for ultrathin or multilayer composite films, existing devices struggle to achieve gradient cooling, affecting the shaping effect. Utility Model Content

[0005] To address the problems mentioned in the background section, this application provides a stretching PVDC film shaping device.

[0006] The stretching PVDC film shaping equipment provided in this application adopts the following technical solution: A stretching PVDC film shaping equipment includes a support, a feed pipe is provided on the top of the support, a cooling and shaping component is provided on the top of the feed pipe, and a film body is provided on the top of the cooling and shaping component.

[0007] A cooling and shaping assembly includes a cooling air regulating pipe, cooling holes, a sealing plate, a servo motor, a lead screw, an internal thread block, and a limiting groove. The cooling air regulating pipe is located inside the film body. Cooling holes are opened on one side of the cooling air regulating pipe at a 30° angle. A sealing plate is fixedly connected to the top of the cooling air regulating pipe. A servo motor is fixedly installed on the top of the sealing plate. A lead screw is fixedly installed at the output end of the servo motor. An internal thread block is threaded onto one side of the lead screw. A limiting groove is opened inside the cooling air regulating pipe, and protrusions on both sides of the internal thread block are movably connected inside the limiting groove.

[0008] The above scheme uses a servo motor to drive the lead screw to precisely control the displacement of the internal thread block, and the tilted cooling hole is used to adjust the angle of the cold air injection, which effectively improves the uniformity of film cooling. At the same time, the limiting groove structure prevents movement deviation.

[0009] Optionally, the cooling and shaping assembly further includes a forming cavity shell, a cooling cavity shell, and a threaded groove. The forming cavity shell is fixedly connected to the top of the feed pipe, and there is a 2-3mm gap between the forming cavity shell and the cooling cavity shell for blow molding the film body. The cooling cavity shell is fixedly installed inside the forming cavity shell through a perforated plate at the bottom, and the threaded groove is opened inside the cooling air regulating pipe.

[0010] The above scheme forms a blow molding channel with a 2-3mm gap between the two cavities. Combined with the bottom multi-hole plate, it achieves uniform diffusion of cold air. The design of the threaded groove and the lead screw pitch are consistent to ensure the movement accuracy of the internal thread block and avoid cold air leakage.

[0011] Optionally, the cooling holes include multiple sets of circumferentially arrayed cold air exhaust holes, and the multiple sets of cold air exhaust holes are arranged at equal intervals from top to bottom on one side of the cold air regulating pipe. The height of the internal thread block is greater than the height of a single cooling hole, and a sealing ring is provided on the contact surface between the internal thread block and the inner wall of the cold air regulating pipe.

[0012] The above scheme, with its equidistant multi-layer cooling holes and internal thread block height design, allows for segmented control of the cooling air coverage area. The fluororubber sealing ring ensures airtightness and adapts to the cooling intensity requirements of different film thicknesses.

[0013] Optionally, the interior of the cooling chamber shell is equipped with a cooler and an exhaust fan, through which cold air is blown from the bottom of the cooling air regulating pipe to the top of the cooling air regulating pipe.

[0014] The above solution uses a frequency converter to adjust the exhaust fan speed, dynamically control the airflow and pressure, and combines this with precise temperature control of the refrigeration unit to achieve rapid film shaping and optimized energy consumption.

[0015] Optionally, the pitch of the threaded groove is the same as the pitch of the lead screw, and the internal threaded block forms a linear kinematic fit with the lead screw through the threaded groove.

[0016] Through the above scheme, the pitch consistency design enables the internal thread block and the lead screw to form a precise linear fit, eliminating motion errors and ensuring the response speed and positioning accuracy of the cooling hole opening and closing adjustment.

[0017] Optionally, the sealing ring is made of fluororubber, and its outer diameter is interference-fitted with the inner diameter of the air conditioning pipe to ensure airtightness between the air conditioning pipe and the internal threaded block.

[0018] Through the above solutions, the high elasticity and low temperature resistance of fluororubber effectively compensate for component tolerances, and the interference fit design maintains excellent sealing performance even at -20℃, extending the equipment maintenance cycle.

[0019] Optionally, the limiting groove is a vertical T-shaped groove, and the protrusions on both sides of the internal thread block are T-shaped structures, which slide with the limiting groove to prevent the internal thread block from rotating.

[0020] The above scheme effectively constrains the rotational freedom of the internal thread block by sliding the T-slot and the protrusion, ensuring the smoothness of linear motion in the vertical direction and avoiding the risk of seal failure caused by deflection.

[0021] Optionally, the bottom of the cooling cavity shell has a porous disk with a diameter of 0.8-1.2 mm evenly distributed air guide holes for uniformly introducing cold air into the interior of the forming cavity shell.

[0022] The above scheme enables the cold gas laminar flow distribution with a precision aperture design of 0.8-1.2mm, eliminates the surface ripple defects of the thin film caused by turbulence, and significantly improves the optical performance of the product.

[0023] Optionally, the speed of the exhaust fan is adjusted by a frequency converter to control the airflow to adapt to the shaping requirements of films of different thicknesses.

[0024] Through the above scheme, frequency conversion control can automatically match the cold air flow rate according to the film extrusion speed and thickness, realize digital control of process parameters, and enhance the adaptability of equipment and the level of intelligent production.

[0025] In summary, this application includes the following beneficial technical effects:

[0026] 1. This utility model incorporates components such as a cooling air regulating pipe, cooling holes, a servo motor, and a lead screw. The servo motor drives the lead screw in a threaded transmission engagement with an internal threaded block, enabling the internal threaded block to move linearly along the limiting groove of the cooling air regulating pipe. This allows for precise control of the cooling air flow rate by adjusting the area of ​​the internal threaded block blocking the cooling holes. The 30° inclined cooling hole design, combined with an equidistant array layout, allows the cooling air to act uniformly on the inner wall of the film body in a spiral airflow pattern, effectively avoiding the temperature gradient differences caused by traditional direct-blowing cooling. This achieves the effect of uniformly cooling and shaping films of different thicknesses by dynamically adjusting the cooling air flow rate.

[0027] 2. This utility model, through the design of a forming cavity shell, a cooling cavity shell, and a perforated plate, utilizes a 2-3mm annular gap between the forming cavity shell and the cooling cavity shell. Combined with evenly distributed 0.8-1.2mm air guide holes on the perforated plate, this allows cold air from the cooling cavity to stably enter the forming cavity in a laminar flow manner. This, in turn, provides radially uniform cooling to the film body during the blow molding process through an annular airflow field. The linkage control design between the exhaust fan speed and the frequency converter allows for real-time adjustment of the cold air flow rate according to the film thickness. Combined with the fluororubber sealing ring ensuring the airtightness of the cold air regulating pipe, this device achieves the effect of efficiently shaping films of different specifications through dynamic matching of airflow parameters. Attached Figure Description

[0028] Figure 1 This is a schematic diagram of the overall structure in an embodiment of this application;

[0029] Figure 2 This is a partial structural diagram of an embodiment of this application;

[0030] Figure 3 This is a partial structural diagram of the cooling and shaping component in an embodiment of this application;

[0031] Figure 4 This is a schematic diagram of the partial structure installation of the cooling and shaping component in an embodiment of this application.

[0032] Reference numerals: 1. Support; 2. Feed pipe; 3. Cooling and shaping assembly; 301. Forming cavity shell; 302. Cooling cavity shell; 303. Cooling air regulating pipe; 304. Cooling hole; 305. Sealing plate; 306. Servo motor; 307. Lead screw; 308. Internal thread block; 309. Limiting groove; 310. Threaded groove; 4. Film body. Detailed Implementation

[0033] The following is in conjunction with the appendix Figure 1-4 This application will be described in further detail.

[0034] This application discloses a stretching PVDC film shaping device.

[0035] Please see Figure 1 A stretching PVDC film shaping device includes a support 1, a feed pipe 2 is provided on the top of the support 1, a cooling and shaping component 3 is provided on the top of the feed pipe 2, and a film body 4 is provided on the top of the cooling and shaping component 3.

[0036] Please see Figures 2 to 4 The cooling and shaping component 3 includes a cooling air regulating pipe 303, cooling holes 304, a sealing plate 305, a servo motor 306, a lead screw 307, an internal thread block 308, and a limiting groove 309. The cooling air regulating pipe 303 is located inside the film body 4. Cooling holes 304 are opened on one side of the cooling air regulating pipe 303, and the cooling holes 304 are opened at an angle of 30°. The sealing plate 305 is fixedly connected to the top of the cooling air regulating pipe 303. The servo motor 306 is fixedly installed on the top of the sealing plate 305. The lead screw 307 is fixedly installed at the output end of the servo motor 306. The internal thread block 308 is threaded onto one side of the lead screw 307. The limiting groove 309 is opened inside the cooling air regulating pipe 303, and the protrusions on the left and right sides of the internal thread block 308 are movably connected inside the limiting groove 309.

[0037] The cooling and shaping assembly 3 also includes a forming cavity housing 301, a cooling cavity housing 302, and a threaded groove 310. The forming cavity housing 301 is fixedly connected to the top of the feed pipe 2. The forming cavity housing 301 and the cooling cavity housing 302 are spaced 2-3 mm apart for blow molding the film body 4. The cooling cavity housing 302 is fixedly installed inside the forming cavity housing 301 through a perforated plate at the bottom. The threaded groove 310 is opened inside the cooling air regulating pipe 303.

[0038] The cooling hole 304 includes multiple sets of circumferentially arrayed cold air exhaust holes, and the multiple sets of cold air exhaust holes are arranged at equal intervals from top to bottom on one side of the cold air regulating pipe 303. The height of the internal thread block 308 is greater than the height of a single hole of the cooling hole 304, and a sealing ring is provided on the contact surface between the internal thread block 308 and the inner wall of the cold air regulating pipe 303.

[0039] The cooling chamber housing 302 is equipped with a cooler and an exhaust fan. The exhaust fan blows cold air from the bottom of the cooling air regulating pipe 303 to the top of the cooling air regulating pipe 303.

[0040] The pitch of the threaded groove 310 is the same as the pitch of the lead screw 307, and the internal threaded block 308 forms a linear motion fit with the lead screw 307 through the threaded groove 310.

[0041] The sealing ring is made of fluororubber, and its outer diameter is interference-fitted with the inner diameter of the air conditioning pipe 303 to ensure the airtightness between the air conditioning pipe 303 and the internal threaded block 308.

[0042] The limiting groove 309 is a vertical T-shaped groove, and the protrusions on both sides of the internal thread block 308 are T-shaped structures, which slide with the limiting groove 309 to prevent the internal thread block 308 from rotating.

[0043] The bottom of the cooling cavity shell 302 has a perforated plate with evenly distributed air guide holes of 0.8-1.2mm in diameter, which are used to evenly introduce cold air into the interior of the forming cavity shell 301.

[0044] The speed of the exhaust fan is adjusted by a frequency converter to control the airflow to meet the shaping requirements of the thin film body 4 with different thicknesses.

[0045] Further explanation is needed: The cooling and shaping component 3, as the core component of the stretching PVDC film shaping equipment, mainly undertakes two core functions: dynamic cooling airflow regulation and uniform cooling and shaping. This mechanism achieves precise control of cooling airflow parameters through the coordinated action of the cooling air regulating pipe 303, servo motor 306, and lead screw 307 transmission system. When the servo motor 306 drives the lead screw 307 to rotate, the internal thread block 308 moves linearly along the limiting groove 309 on the inner wall of the cooling air regulating pipe 303. By blocking different numbers of cooling holes 304, the cooling air flow rate is infinitely adjustable. The 30° inclined array design of the cooling holes 304, combined with the reciprocating motion of the internal thread block 308, allows the cooling air to act uniformly on the inner wall of the film body 4 in a spiral airflow, effectively eliminating the temperature gradient difference problem caused by traditional direct blowing cooling, and ensuring that PVDC films with a thickness of 0.01-0.05mm obtain a uniform radial cooling effect during the blow molding process.

[0046] Another key function of the cooling and shaping component 3 is to create a stable annular airflow field. Through the 2-3mm annular gap structure between the forming cavity shell 301 and the cooling cavity shell 302, combined with the flow equalization design of the bottom perforated plate, the low-temperature airflow in the cooling cavity shell 302 is introduced into the forming cavity in a laminar flow form. The linkage control of the exhaust fan and the frequency converter can adjust the cold air flow rate in real time according to the thickness of the thin film body 4, with an adjustment range of 5-20m. 3 With a speed of 0.5-2℃ / s, combined with a fluororubber sealing ring to ensure the airtightness of the airflow channel, this mechanism ensures that films of different specifications can achieve the optimal cooling rate of 0.5-2℃ / s within the blow-up ratio range of 1.5-3.0. Through dynamic matching of airflow parameters and blow molding process, this mechanism can control the transverse shrinkage rate of the film within ±2% and increase the longitudinal tensile strength to 50-70MPa, significantly improving the optical transparency and mechanical property consistency of PVDC films, and meeting the high-precision application requirements of food packaging, medical devices and other fields.

[0047] The implementation principle of the stretching PVDC film shaping equipment in this application is as follows:

[0048] First, the raw material enters the annular gap between the molding cavity shell 301 and the cooling cavity shell 302 through the feed pipe 2, and forms the initial tubular film body 4 under the action of blow molding air pressure.

[0049] Secondly, the refrigerator inside the cooling chamber shell 302 cools the air to -10℃ to 5℃, and the exhaust fan operates at a speed of 5-20m. 3 The flow rate of / min will evenly introduce the cold air into the cold air regulating pipe 303 through the perforated plate with a diameter of 0.8-1.2mm.

[0050] Next, the servo motor 306 drives the lead screw 307 to rotate, causing the internal thread block 308 to move linearly along the limiting groove 309. By adjusting its shielding area on the 30° inclined cooling hole 304, the airflow rate is precisely controlled from 0.3 to 1.5 m³ / h. 3 / min.

[0051] Next, spiral-shaped cold air acts on the inner wall of the film body 4 at a cooling rate of 0.5-2℃ / s, which, together with the natural convection of the outer layer, forms an internal and external temperature gradient ΔT = 15-25℃, promoting the directional alignment of molecular chains.

[0052] Finally, the film, shaped by dynamic airflow control, is adjusted by a frequency converter to match different blow-up ratios of 1.5-3.0, ultimately forming a high-quality PVDC film with a transverse shrinkage rate of ±2% and a longitudinal tensile strength of 50-70MPa, which is then wound up by a traction device.

[0053] The above are all preferred embodiments of this application, and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.

Claims

1. A stretching PVDC film shaping device, comprising a support (1), characterized in that: The top of the support (1) is provided with a feed pipe (2), the top of the feed pipe (2) is provided with a cooling and shaping assembly (3), and the top of the cooling and shaping assembly (3) is provided with a film body (4). A cooling and shaping assembly (3) includes a cooling air regulating pipe (303), cooling holes (304), a sealing plate (305), a servo motor (306), a lead screw (307), an internal thread block (308), and a limiting groove (309). The cooling air regulating pipe (303) is disposed inside the film body (4). Cooling holes (304) are provided on one side of the cooling air regulating pipe (303), and the cooling holes (304) are opened at an angle of 30°. A sealing plate (305) is fixedly connected to the top of the air conditioning pipe (303). A servo motor (306) is fixedly installed on the top of the sealing plate (305). A lead screw (307) is fixedly installed at the output end of the servo motor (306). An internal thread block (308) is threaded onto one side of the lead screw (307). A limiting groove (309) is opened inside the air conditioning pipe (303), and the protrusions on the left and right sides of the internal thread block (308) are movably connected inside the limiting groove (309).

2. The stretching PVDC film shaping equipment according to claim 1, characterized in that: The cooling and shaping assembly (3) further includes a forming cavity shell (301), a cooling cavity shell (302), and a threaded groove (310). The forming cavity shell (301) is fixedly connected to the top of the feed pipe (2). The forming cavity shell (301) and the cooling cavity shell (302) are spaced 2-3 mm apart for blow molding the film body (4). The cooling cavity shell (302) is fixedly installed inside the forming cavity shell (301) through a perforated plate at the bottom. The threaded groove (310) is opened inside the cooling air regulating pipe (303).

3. The stretching PVDC film shaping equipment according to claim 1, characterized in that: The cooling hole (304) includes multiple sets of circumferentially arrayed cold air discharge holes, and the multiple sets of cold air discharge holes are arranged at equal intervals from top to bottom on one side of the cold air regulating pipe (303). The height of the internal thread block (308) is greater than the height of a single hole of the cooling hole (304), and a sealing ring is provided on the contact surface between the internal thread block (308) and the inner wall of the cold air regulating pipe (303).

4. The stretching PVDC film shaping equipment according to claim 2, characterized in that: The cooling chamber housing (302) is equipped with a cooler and an exhaust fan. The exhaust fan blows cold air from the bottom of the cooling air regulating pipe (303) to the top of the cooling air regulating pipe (303).

5. The stretching PVDC film shaping equipment according to claim 2, characterized in that: The pitch of the threaded groove (310) is the same as the pitch of the lead screw (307), and the internal threaded block (308) forms a linear motion fit with the lead screw (307) through the threaded groove (310).

6. The stretching PVDC film shaping equipment according to claim 3, characterized in that: The sealing ring is made of fluororubber, and its outer diameter is interference-fitted with the inner diameter of the air conditioning pipe (303) to ensure the airtightness between the air conditioning pipe (303) and the internal threaded block (308).

7. The stretching PVDC film shaping equipment according to claim 1, characterized in that: The limiting groove (309) is a vertical T-shaped groove, and the protrusions on both sides of the internal thread block (308) are T-shaped structures, which slide with the limiting groove (309) to prevent the internal thread block (308) from rotating.

8. The stretching PVDC film shaping equipment according to claim 2, characterized in that: The bottom of the cooling cavity shell (302) has a porous disk with a diameter of 0.8-1.2 mm, which is uniformly distributed to guide cold air into the interior of the forming cavity shell (301).

9. The stretching PVDC film shaping equipment according to claim 4, characterized in that: The speed of the exhaust fan is adjusted by a frequency converter to control the airflow to meet the shaping requirements of the film body (4) of different thicknesses.

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