A web-aligning device for BOPP film production

Abstract

This utility model relates to a web-aligning device for BOPP film production, aiming to solve the technical problems of current web-aligning rollers driven by threaded rods, which not only have long response times and are prone to hysteresis errors at high speeds, but also cause local stretching of the film due to rigid impacts, resulting in wrinkles or holes. The device includes: a base with unwinding and take-up rollers mounted on both sides of its surface for unwinding and take-up of the BOPP film; and a web-aligning mechanism located on the base between the unwinding and take-up rollers. This utility model uses a monitoring component to capture the lateral deviation of the film in real time. The electromagnetic coil current can be adjusted in microseconds, causing a rapid change in the viscosity of the magnetorheological fluid in the corresponding cavity. This allows for stepless switching of the magnetorheological fluid from liquid to semi-solid state, causing the web-aligning roller to undergo adaptive deformation. When the deviation is small, the viscosity is finely adjusted to form a flexible corrective force; when the deviation is large, rigidity is increased to ensure web-aligning efficiency. Compared to traditional threaded rod mechanical transmission, this device shortens the hysteresis time and is suitable for high-speed film production scenarios.

Description

Technical Field

[0001] This utility model relates to the field of BOPP film production technology, specifically to a BOPP film production correction device. Background Technology

[0002] Biaxially oriented polypropylene (BOPP) film is generally a multilayer co-extruded film, made by co-extruded polypropylene granules into sheets, and then stretching them in both longitudinal and transverse directions. Due to the orientation of the stretched molecules, this film has good physical stability, mechanical strength, airtightness, high transparency and gloss, and is tough and wear-resistant, making it a widely used printing film.

[0003] According to publicly available patent CN222540034U, a web-aligning device for BOPP film production includes a base plate, an unwinding roller, and a winding roller. The unwinding roller is installed on the upper left side of the base plate, and the winding roller is installed on the upper right side. A fixed base is installed in the middle of the upper part of the base plate, and a vertical plate is installed on the upper end of the fixed base. Conveyor rollers are symmetrically installed on both ends of the vertical plate. A photoelectric sensor is installed on the upper right end of the vertical plate. A fixed plate is installed at the front end of the base plate. A groove is formed at the upper end of the fixed plate, and a threaded rod is installed inside the groove. A motor is installed at the front end of the threaded rod, and a threaded sleeve is fitted onto the outer surface of the threaded rod, with the threaded sleeve slidably connected to the inner wall of the groove. A support plate is installed at the end, and symmetrically arranged correction rollers are positioned above the upright plate. In the process of developing this invention, the inventors discovered that at least the following problems remain unresolved in the existing technology: The correction rollers rotate synchronously to transport the film, while two brush rollers rotate in opposite directions to clean the film surface. Simultaneously, a dust extraction mechanism uses a suction pipe to remove dust generated during cleaning, ensuring a clean working environment. However, in traditional methods, the correction rollers are driven by a threaded rod, resulting in a long response time, hysteresis errors at high speeds, and the rigid impact can cause localized stretching of the film, leading to wrinkles or holes. Therefore, a new technical solution is needed to address these issues. Utility Model Content

[0004] The purpose of this utility model is to overcome the shortcomings of the existing technology, adapt to the needs of reality, and provide a correction device for BOPP film production. This device solves the technical problems of the current method of using a threaded rod to drive the correction roller to deviate, which not only has a long response time and is prone to hysteresis error at high speeds, but also causes local stretching of the film due to rigid impact, resulting in wrinkles or holes.

[0005] To achieve the objective of this utility model, the technical solution adopted is as follows: A web-aligning device for BOPP film production is designed, comprising:

[0006] A base, on which unwinding rollers and take-up rollers are respectively installed on both sides of the surface of the base, for realizing the unwinding and take-up of BOPP film;

[0007] A web-correcting mechanism, located on a base between the unwinding roller and the take-up roller, is used to laterally correct the BOPP film during the conveying process. The web-correcting mechanism includes:

[0008] Two columns are symmetrically fixedly connected to the two sides of the middle part of the base surface. A hollow correction roller is provided between the two columns, and a connecting shaft is fixedly connected to both ends of the correction roller.

[0009] A partition is fixedly connected to the middle of the inner cavity of the correction roller, dividing the inner cavity of the correction roller into two independent cavities, both of which are filled with magnetorheological fluid.

[0010] Two electromagnetic coils are respectively sleeved on both sides of the outside of the correction roller, and correspond one-to-one with the two cavities;

[0011] The monitoring component, mounted on two columns and located on the feed side of the correction roller, is used to monitor the lateral offset of the BOPP film in real time and trigger the current adjustment of the electromagnetic coil to achieve automatic correction.

[0012] Preferably, the monitoring component includes:

[0013] Two mounting plates are fixedly connected to the feed side of the two columns near the correction roller. Photoelectric sensing devices are installed on opposite ends of the two mounting plates, and the two photoelectric sensing devices correspond to the two side edges of the BOPP film.

[0014] A control processor is fixedly connected to one of the outer ends of one of the columns;

[0015] The current regulator is fixedly connected to the column above the control processor. The photoelectric sensing device is electrically connected to the two electromagnetic coils via wires passing through the control processor and the circuit regulator in sequence.

[0016] Preferably, a support rod is fixedly connected to the bottom of each of the two electromagnetic coils, the other end of the support rod is connected to the surface of the base, and the axes of the two electromagnetic coils are collinear with the axis of the correction roller.

[0017] Preferably, a base plate is fixedly connected to the bottom of the support rod, a fixing bolt passes through the base plate, and the fixing bolt is threadedly connected to the surface of the base.

[0018] Preferably, both sides of the outer periphery of the correction roller are laser-engraved with spiral grooves, and the thread directions of the spiral grooves on both sides are opposite.

[0019] Preferably, the spiral groove has a depth of 0.1 mm, a groove width of 2 mm, and rounded edges.

[0020] Preferably, a bearing seat is fixedly installed on the top of each of the two columns, and the two connecting shafts are rotatably installed in the two bearing seats respectively.

[0021] Preferably, the correction roller is integrally formed from austenitic stainless steel.

[0022] Compared with the prior art, the beneficial effects of this utility model are as follows:

[0023] 1. High-speed response with no lag: After the monitoring component captures the lateral displacement of the film in real time, the electromagnetic coil current can be adjusted in microseconds, causing the viscosity of the magnetorheological fluid in the corresponding cavity to change rapidly. This allows the magnetorheological fluid to be steplessly switched from liquid to semi-solid state, driving the correction roller to produce adaptive deformation. When the displacement is small, the viscosity is finely adjusted to form a flexible correction force. When the displacement is large, the rigidity is increased to ensure the correction efficiency. Compared with the traditional threaded rod mechanical transmission, the lag time is shortened, making it suitable for high-speed film production scenarios.

[0024] 2. Flexible correction and damage prevention: The controllable viscosity characteristics of magnetorheological fluid make the correction force change linearly without rigid abrupt changes. It can automatically match the correction strength according to the film thickness and tension, avoiding local stretching or tearing caused by the "hard push" of traditional threaded rods, and protecting the flatness and mechanical properties of the film surface.

[0025] 3. Adaptive operating conditions: Through the independent control design of the dual chambers, the magnetorheological fluid state on both sides of the correction roller can be adjusted separately to adapt to the single or double side offset of the film. Compared with the traditional integral correction roller, the adjustment accuracy is improved. At the same time, the magnetorheological fluid has no mechanical wear, which solves the problem of accuracy decay caused by friction in the threaded rod drive and extends the equipment life. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of the overall structure of this utility model;

[0027] Figure 2 This is a schematic diagram of the corrective roller structure of this utility model;

[0028] Figure 3 This is a cross-sectional view of the correction roller of this utility model.

[0029] In the diagram: 1. Base; 11. Unwinding roller; 12. Rewinding roller; 2. Column; 21. Bearing seat; 3. Correcting roller; 31. Connecting shaft; 32. Spiral groove; 33. Partition plate; 34. Magnetorheological fluid; 4. Mounting plate; 41. Photoelectric sensor; 42. Control processor; 43. Current regulator; 5. Electromagnetic coil; 51. Support rod; 52. Base plate; 53. Fixing bolt. Detailed Implementation

[0030] The present invention will be further described below with reference to the accompanying drawings and embodiments:

[0031] Example 1: A web-aligning device for BOPP film production, see [link to example]. Figures 1 to 3 ,include:

[0032] A base 1, on which an unwinding roller 11 and a winding roller 12 are respectively installed on both sides of the surface of the base 1, for realizing the unwinding and winding of BOPP film;

[0033] A web-correcting mechanism, located on a base 1 between the unwinding roller 11 and the take-up roller 12, is used to laterally correct the BOPP film during the conveying process. The web-correcting mechanism includes:

[0034] Two columns 2 are symmetrically fixedly connected to the two sides of the middle part of the surface of the base 1. A hollow correction roller 3 is provided between the two columns 2. Both ends of the correction roller 3 are fixedly connected to a connecting shaft 31.

[0035] The partition 33 is fixedly connected to the middle of the inner cavity of the correction roller 3, dividing the inner cavity of the correction roller 3 into two independent cavities, both of which are filled with magnetorheological fluid 34.

[0036] Two electromagnetic coils 5 are respectively sleeved on both sides of the outside of the correction roller 3, and correspond one-to-one with the two cavities;

[0037] The monitoring component, mounted on two columns 2 and located on the feed side of the correction roller 3, is used to monitor the lateral offset of the BOPP film in real time and trigger the current adjustment of the electromagnetic coil 5 to achieve automatic correction.

[0038] This device, through its correction mechanism and monitoring components, achieves the following during use:

[0039] High-speed response with no lag: After the monitoring component captures the lateral displacement of the film in real time, the current of the electromagnetic coil 5 can be adjusted in microseconds, which makes the viscosity of the magnetorheological fluid 34 in the corresponding cavity change rapidly, and the magnetorheological fluid 34 is steplessly switched from liquid to semi-solid state, which drives the correction roller 3 to produce adaptive deformation. When the displacement is small, the viscosity is finely adjusted to form a flexible correction force, and when the displacement is large, the rigidity is increased to ensure the correction efficiency. Compared with the traditional threaded rod mechanical transmission, the lag time is shortened, which is suitable for high-speed film production scenarios.

[0040] Flexible correction and damage prevention: The controllable viscosity characteristics of magnetorheological fluid 34 make the correction force change linearly without rigid abrupt changes. It can automatically match the correction strength according to the film thickness and tension, avoiding local stretching or tearing caused by the "hard push" of traditional threaded rods, and protecting the flatness and mechanical properties of the film surface.

[0041] Adaptive operating conditions: Through the independent control design of the dual chambers, the state of the magnetorheological fluid 34 on both sides of the correction roller 3 can be adjusted separately to adapt to the single or double side offset of the film. Compared with the traditional integral correction roller 3, the adjustment accuracy is improved. At the same time, the magnetorheological fluid 34 has no mechanical wear, which solves the problem of accuracy decay caused by friction in the threaded rod drive and extends the service life of the equipment.

[0042] When the alignment roller 3 comes into contact with the BOPP film, the BOPP film exerts a small pressure on the surface of the alignment roller 3. When the local stiffness of the alignment roller 3 increases, for example, the right area becomes hard due to the solidification of the magnetorheological fluid 34, the wall of the alignment roller 3 in this area hardly undergoes elastic deformation, which is equivalent to forming a rigid fulcrum. The contact pressure with the BOPP film will increase relatively because it is not easy to give way. On the other hand, the wall of the alignment roller 3 in the low stiffness area (such as the left side) will undergo a small deformation due to the pressure, and the contact pressure is relatively small. This will create a pressure gradient on the contact surface between the film and the roller. Since there is friction between the film and the surface of the alignment roller 3, the magnitude of the friction force is positively correlated with the contact pressure. Therefore, the frictional force on the film from the high-stiffness area (high pressure) is significantly greater than that from the low-stiffness area (low pressure). When the alignment roller 3 rotates, this difference in frictional force will decompose into lateral components. For example, when the BOPP film shifts to the left, the frictional force in the high-stiffness area on the right is greater, which will generate a lateral force to the right on the film; the frictional force in the low-stiffness area on the left is small, and the leftward component of the force on the film can be ignored. This directional lateral component will "push" the film to the right (alignment direction), and as the alignment roller 3 continues to rotate, the component will act continuously on the film, gradually offsetting the shifting trend.

[0043] For details, see Figure 1 The monitoring component includes: two mounting plates 4, which are fixedly connected to the feed side of the two columns 2 near the correction roller 3. Photoelectric sensors 41 are installed on opposite ends of the two mounting plates 4, and the two photoelectric sensors 41 correspond to the two side edges of the BOPP film. A control processor 42 is fixedly connected to one of the outer ends of one of the columns 2. A current regulator 43 is fixedly connected to the column 2 above the control processor 42. The photoelectric sensors 41 are electrically connected to the two electromagnetic coils 5 through wires via the control processor 42 and the circuit regulator. By precisely aligning the photoelectric sensors 41 with the film edge, minute deviations can be captured. When the control processor 42 receives the photoelectric signal, it dynamically outputs an adaptive current through the current regulator 43 to steplessly adjust the magnetic field strength of the electromagnetic coils 5, realizing real-time matching between the state of the magnetorheological fluid 34 and the deviation. The entire chain from monitoring to correction is automatically completed, and the response speed is synchronized with the film production speed, meeting the stability requirements of large-scale continuous production.

[0044] Further, see Figure 1Each of the two electromagnetic coils 5 has a support rod 51 fixedly connected to its bottom. The other end of the support rod 51 is connected to the surface of the base 1. The axes of the two electromagnetic coils 5 are collinear with the axis of the correction roller 3. The support rod 51 provides stable support for the electromagnetic coils 5, preventing the coils from shifting due to vibration during high-speed operation. This ensures the coaxiality of the coils and the correction roller 3, allowing the magnetic field to act uniformly on the internal magnetorheological fluid 34, and ensuring the symmetry and precision of stiffness adjustment.

[0045] It is worth noting that, see Figure 1 The bottom of the support rod 51 is fixedly connected to a base plate 52, and a fixing bolt 53 passes through the base plate 52. The fixing bolt 53 is threadedly connected to the surface of the base 1. The support rod 51 and the base 1 are rigidly connected through the cooperation of the base plate 52 and the fixing bolt 53. This can effectively counteract the electromagnetic force reaction when the electromagnetic coil 5 is working, and avoid loosening or displacement after long-term use. The threaded connection of the fixing bolt 53 is easy to disassemble and maintain, and the connection strength is high. It can adapt to high-frequency vibration in the production process and ensure the structural stability of the device during long-term operation.

[0046] It is worth noting that, see Figure 2 The outer sides of the correction roller 3 are laser-engraved with spiral grooves 32, and the spiral grooves 32 on both sides are in opposite directions. With the spiral grooves 32, when the BOPP film is transported at high speed, the BOPP film and the correction roller 3 are prone to forming an air film due to air retention, which can easily lead to poor contact and slippage. The spiral grooves 32 can discharge the gap air through micro-vortex flow, enhance the adhesion between the film and the correction roller 3, and reduce the risk of slippage. At the same time, the reverse spiral grooves 32 can guide the airflow to form a bidirectional lateral force when the correction roller 3 rotates, which helps to counteract the inertial offset of the film during high-speed transport. It works synergistically with the stiffness adjustment of the magnetorheological fluid 34, and will not cause the BOPP film to shift laterally or shake.

[0047] It is worth mentioning that, see Figure 2 The spiral groove 32 has a depth of 0.1 mm and a width of 2 mm. The edges of the spiral groove 32 are rounded. Since the depth of the spiral groove 32 is 0.1 mm, which is much less than one-third of the thickness of the BOPP film, the BOPP film will adhere tightly to the surface of the correction roller 3 under tension. The spiral groove 32 will not cause the BOPP film to embed or wrinkle. The BOPP film only contacts the edges of the spiral groove 32, not the bottom of the groove. The contact area is small, and the impact on tension distribution is negligible. In addition, the rounded corners can eliminate the risk of sharp edges scratching the film and ensure the stability of high-speed BOPP film transportation.

[0048] It is worth mentioning that, see Figure 1Each of the two columns 2 is fixedly mounted with a bearing seat 21 on its top. The two connecting shafts 31 are rotatably mounted in the two bearing seats 21 respectively. The bearing seats 21 can reduce the rotational resistance of the connecting shafts 31, so that the correction roller 3 can rotate synchronously with the film at high speed, avoiding film stretching or lag caused by frictional resistance. At the same time, the stability of the rotational fit can reduce the radial runout of the roller body, ensure the uniformity of the stiffness adjustment of the magnetorheological fluid 34, and improve the reliability of the device in long-term high-speed operation.

[0049] It is worth mentioning that, see Figure 2 The correction roller 3 is integrally formed from austenitic stainless steel. The non-magnetic properties of austenitic stainless steel can avoid shielding the magnetic field generated by the electromagnetic coil 5, ensuring that the magnetic field can efficiently penetrate the roller body and act on the internal magnetorheological fluid 34, thus ensuring the response sensitivity of stiffness adjustment. In addition, the surface of this material is smooth and has excellent wear resistance, so it is not easy to scratch or wear when in contact with BOPP film, which is suitable for the easily damaged characteristics of BOPP film.

[0050] In addition, all components designed in this utility model are general standard parts or components known to those skilled in the art. Their structure and principle can be learned by those skilled in the art through technical manuals or conventional experimental methods. Those skilled in the art can fully implement them, so there is no need to elaborate. The content protected by this utility model does not involve improvements to the internal structure and method.

[0051] The embodiments disclosed herein are preferred embodiments, but are not limited thereto. Those skilled in the art can readily grasp the spirit of this utility model based on the above embodiments and make different extensions and variations. However, as long as they do not depart from the spirit of this utility model, they are all within the protection scope of this utility model.

Claims

1. A deviation rectifying device for BOPP film production, characterized in that, include: The base (1) has an unwinding roller (11) and a winding roller (12) installed on both sides of its surface to realize the unwinding and winding of BOPP film. A web-correcting mechanism is located on a base (1) between the unwinding roller (11) and the take-up roller (12) for laterally correcting the BOPP film during transport. The web-correcting mechanism includes: Two columns (2) are symmetrically fixedly connected to the two sides of the middle part of the surface of the base (1). A hollow correction roller (3) is provided between the two columns (2). Both ends of the correction roller (3) are fixedly connected to a connecting shaft (31). The partition (33) is fixedly connected to the middle of the inner cavity of the correction roller (3), dividing the inner cavity of the correction roller (3) into two independent cavities, both of which are filled with magnetorheological fluid (34). Two electromagnetic coils (5) are respectively sleeved on the outer sides of the correction roller (3) and correspond one-to-one with the two cavities; The monitoring component is mounted on two columns (2) and located on the feed side of the correction roller (3). It is used to monitor the lateral offset of the BOPP film in real time and trigger the current adjustment of the electromagnetic coil (5) to achieve automatic correction.

2. A deviation rectifying device for BOPP film production as claimed in claim 1, wherein, The monitoring components include: Two mounting plates (4) are fixedly connected to the feed side of the two columns (2) near the correction roller (3). Photoelectric sensing devices (41) are installed on opposite ends of the two mounting plates (4). The two photoelectric sensing devices (41) correspond to the two sides of the BOPP film respectively. A control processor (42) is fixedly connected to one of the outer ends of one of the columns (2); The current regulator (43) is fixedly connected to the column (2) above the control processor (42). The photoelectric sensing device (41) is electrically connected to the two electromagnetic coils (5) through wires passing through the control processor (42) and the circuit regulator in sequence.

3. A deviation rectifying device for BOPP film production as claimed in claim 1 wherein, The bottom of each of the two electromagnetic coils (5) is fixedly connected to a support rod (51), the other end of the support rod (51) is connected to the surface of the base (1), and the axis of the two electromagnetic coils (5) is collinear with the axis of the correction roller (3).

4. A deviation rectifying device for BOPP film production as claimed in claim 3, wherein, The bottom of the support rod (51) is fixedly connected to a base plate (52), and a fixing bolt (53) passes through the base plate (52), and the fixing bolt (53) is threadedly connected to the surface of the base (1).

5. A deviation rectifying device for BOPP film production as claimed in claim 1 wherein, The outer periphery of the correction roller (3) is laser-engraved with spiral grooves (32) on both sides, and the spiral grooves (32) on both sides have opposite thread directions.

6. A deviation rectifying device for BOPP film production as claimed in claim 5 wherein, The spiral groove (32) has a depth of 0.1 mm and a groove width of 2 mm, and the edges of the spiral groove (32) are rounded.

7. A deviation rectifying device for BOPP film production as claimed in claim 1 wherein, The top of each of the two columns (2) is fixedly installed with a bearing seat (21), and the two connecting shafts (31) are rotatably installed in the two bearing seats (21).

8. A deviation rectifying device for BOPP film production as claimed in claim 1 wherein, The correction roller (3) is integrally formed from austenitic stainless steel.

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