A film stretching apparatus

Abstract

This utility model discloses a film stretching device, belonging to the field of film stretching. It includes a support frame with a housing; two sets of fixed seats, with a fixed roller mounted on a bearing between the two sets of fixed seats, and a stretching roller correspondingly positioned above the fixed roller; an air supply assembly, including at least two air supply sections, each including a support plate mounted on a top plate, with a movable plate sliding on the support plate. The movable plate has multiple sets of outwardly diffusing grooves, which are connected to a pitch-changing unit via pulleys. The pitch-changing unit includes a moving rod, with a guide head mounted at the right-angle end of the moving rod. The multiple guide heads are connected by a split pipe, each with a single air inlet port; a limiting part is installed on the support plate, and a moving unit is also installed on the support plate. This film stretching device, through the sliding of the movable plate in the air supply section, causes the pitch-changing unit to slide via the grooves and pulleys. The orthogonal constraint of the limiting part enables synchronous pitch change of the guide heads, and the moving unit adjusts as needed, ensuring hot air coverage for films of different widths.

Description

Technical Field

[0001] This utility model relates to the field of roll forming technology, and in particular to a film stretching device. Background Technology

[0002] In modern industrial production, thin films, as an important basic material, are widely used in packaging, electronics, optics, and many other fields. Thin film stretching is a key process that determines the performance of thin films. By stretching, the molecular orientation of the film can be changed, thereby improving its physical properties such as strength and transparency. Currently, stretching operations are mostly performed using thin film stretching machines.

[0003] For example, patent CN220700377U discloses a stretching mechanism for PE film processing, including a housing, a front side plate, a PE film body, and auxiliary devices. The auxiliary devices include an adjusting seat, a slider, a fixing block, a fastening nut, a fixing roller, a stretching roller, a sealing plate, and an air supply assembly. By loosening the fastening nut, the slider can be pulled up and down to slide, thereby adjusting the gap between the fixing roller and the stretching roller. This facilitates the passage of PE film bodies of different thicknesses, and allows for adjustment during PE film stretching. This enables the stretching of films of different thicknesses after heating, improving the practicality of the mechanism and making it more convenient to use.

[0004] In the above-described solution, symmetrically arranged air guides correspond to the upper and lower surfaces of the central section of the film during the film stretching process. However, when processing films of different widths, the fixed spacing between the air guides leads to insufficient hot air coverage in the film areas at the boundaries. This results in the boundary films receiving less heat than the central areas and heating at a slower rate, causing uneven heating of the entire film. This affects the uniformity of the film's thickness and the consistency of its mechanical properties after stretching, leading to problems such as low heating efficiency and uneven temperature distribution at the boundaries of films of different widths. Therefore, a film stretching device needs to be designed.

[0005] It should be noted that the information disclosed in this background section is only for understanding the background technology of this application concept, and therefore may include information that does not constitute prior art. Utility Model Content

[0006] This utility model provides a film stretching device to solve the problem of insufficient hot air coverage and uneven heating at the boundaries of films of different widths due to the fixed spacing between the upper and lower symmetrical air guides during film stretching.

[0007] The present invention adopts the following technical solution: a film stretching device. It mainly includes a support frame on which a housing is mounted; two sets of fixed seats mounted on the support frame, with a fixed roller mounted on a bearing between the two sets of fixed seats, and a stretching roller correspondingly positioned above the fixed roller; an air supply assembly mounted inside the housing, the air supply assembly including at least two air supply sections, each including a support plate mounted on a top plate, two sets of guide rails arranged on the surface of the support plate, a movable plate connected to the guide rails via a slider, the movable plate having multiple sets of outwardly diffusing grooves, and a pitch-changing unit connected to the grooves via pulleys, the pitch-changing unit including a moving rod, a guide head mounted at the right-angle end of the moving rod, multiple guide heads connected via a split pipe, the split pipe having a single air inlet port; a limiting part mounted on the support plate for constraining the movement trajectory of the pitch-changing unit, and a moving unit mounted on the support plate for driving the multiple pitch-changing units to synchronously change pitch.

[0008] Furthermore, the limiting part includes two sets of slide rails that are fixedly installed on the bearing plate and arranged in parallel with the guide rail direction, and the bottom of the moving rod is correspondingly fixed to the second slider.

[0009] Furthermore, the concave seat 2 of the moving unit is fixed to the bearing plate by bolts, the lead screw 2 is mounted on the concave seat 2 by bearings, the movable seat is threadedly engaged with the lead screw 2 and rigidly connected to the upper surface of the movable plate by bolts, one end of the movable plate is connected to the concave seat 2 by a guide rail slider pair, and the other end relies on the cooperation of the guide rail and the slider 1.

[0010] Furthermore, a driving component is fixedly installed on the bearing plate, and the output shaft of the driving component is fixedly connected to the driving wheel of the transmission part. The transmission part adopts a belt pulley transmission structure, and the driven wheel is coaxially connected to one end of the lead screw.

[0011] Furthermore, the housing is embedded with a heating component, which includes a mounting cover installed on the housing. The housing also has an opening slot adapted to the mounting cover, and a heating box is installed inside the mounting cover. A heating wire is provided near the upper end of the heating box, and at least two sets of fans are embedded at the bottom of the heating box for use with the air supply component. The fans are connected to air guide pipes, and the air guide pipes are connected to the distribution pipes via flexible hoses made of silicone.

[0012] Furthermore, a base is mounted on the side of the moving rod of the rightmost pitch unit, and a laser rangefinder sensor is integrated on the base. A second base is fixed to the side of the moving rod of the leftmost pitch unit, and a receiver adapted to the laser rangefinder sensor is mounted on the second base.

[0013] Furthermore, a PLC controller is mounted on the bracket.

[0014] The above-mentioned technical solutions adopted in the embodiments of this utility model can achieve the following beneficial effects:

[0015] A thin film stretching device enables a movable plate in the air supply section to slide along a guide rail. Its outward-spreading grooves, driven by pulleys, cause a pitch-changing unit to slide radially. Simultaneously, the guide rail and slider of the limiting section form an orthogonal constraint, allowing multiple sets of air guides to move closer or further apart synchronously to adapt to different film widths. When the film width changes, the moving unit drives the air guides to adjust their spacing, ensuring uniform hot air coverage of the entire film surface and avoiding temperature differences in boundary areas due to insufficient coverage. The centralized air inlet design of the splitter pipe, combined with the directional adjustment of the air guides, not only achieves efficient hot air distribution but also uses a laser rangefinder sensor to monitor the air guide spacing in real time, forming a closed-loop control to ensure heating accuracy. This structure ensures uniform heating of the upper and lower surfaces of the film during stretching, effectively improving the heating efficiency and temperature distribution consistency of films of different widths. Attached Figure Description

[0016] The accompanying drawings, which are provided to further illustrate the present invention and constitute a part of the present invention, illustrate exemplary embodiments of the present invention and are used to explain the present invention, but do not constitute an undue limitation of the present invention.

[0017] In the attached diagram:

[0018] Figure 1 This is an overall schematic diagram of a film stretching device according to this application;

[0019] Figure 2 for Figure 1 A partial structural diagram;

[0020] Figure 3 for Figure 2 A partial structural diagram;

[0021] Figure 4 for Figure 3 A partial structural diagram;

[0022] Figure 5 for Figure 4 Enlarged view of point A;

[0023] Figure 6 for Figure 4 A partial structural diagram;

[0024] Figure 7 for Figure 6 A partial structural diagram;

[0025] Figure 8 for Figure 7 A schematic diagram of the bottom structure;

[0026] Figure label:

[0027] 1. Support assembly; 11. Bracket; 12. Housing; 13. Mounting plate; 14. Inlet; 17. Top plate; 2. Tensioning assembly; 21. Fixed seat; 22. Fixed roller; 23. Tensioning roller; 24. Concave seat one; 25. Lead screw one; 26. Sliding seat; 27. Guide rod; 3. Air supply assembly; 31. Bearing plate; 32. Slide rail; 33. Movable plate; 331. Waist groove; 332. Slider one; 333. Guide rail 34. Moving rod; 341. Slider II; 342. Pulley; 35. Air guide head; 36. Diverter pipe; 37. Base I; 38. Laser rangefinder sensor; 39. Base II; 310. Receiver; 311. Drive component; 312. Transmission unit; 313. Concave base II; 314. Lead screw II; 315. Movable seat; 4. Heating assembly; 41. Mounting cover; 42. Heating box; 43. Fan; 44. Air guide pipe. Detailed Implementation

[0028] To further illustrate the technical means and effects adopted by this utility model in order to achieve the intended utility model purpose, the following detailed description of the specific implementation methods, structure, features and effects of this utility model is provided in conjunction with the accompanying drawings and preferred embodiments.

[0029] The technical solutions provided by the various embodiments of this utility model are described in detail below with reference to the accompanying drawings.

[0030] Reference Figures 1-2 As shown, this utility model embodiment provides a film stretching device, including a support component 1, which has a bracket 11, and a box 12 is fixedly installed on the bracket 11 near the center. The box 12 has inlet ports 14 on both sides for film to enter and exit, and two sets of symmetrically arranged mounting plates 13 are fixedly installed on the top of the inner wall of the box 12, with a gap space between the mounting plates 13 and the inner wall side of the box 12.

[0031] Furthermore, a stretching assembly 2 is installed on the support 11. The stretching assembly 2 includes two sets of fixing parts fixedly installed on the support 11 and distributed on both sides of the inside of the box 12 along the film conveying direction. A stretching area for the film to pass through is formed between the two sets of fixing parts. The fixing part includes two sets of fixing seats 21 fixedly installed on the support 11. The two sets of fixing seats 21 are located inside the box 12 near the inner wall on both sides. A rotatable fixing roller 22 is installed between the two sets of fixing seats 21 through a bearing.

[0032] In this application, a first transmission assembly located in the gap space is connected between the roller shafts of the two sets of fixed rollers 22 in the two sets of fixed parts. The first transmission assembly includes a gear set or a synchronous belt pulley mechanism that meshes with each other, for driving the two sets of fixed rollers 22 to rotate synchronously in the same direction and speed, so as to ensure the stability of the film during the transport process.

[0033] like Figures 4-5 As shown, a stretching roller 23 is positioned above the fixed roller 22, and the two are symmetrically distributed to form a film stretching area. Adjustment sections are provided on the outer sides of the two sets of mounting plates 13 to regulate the distance between the two rollers. Each adjustment section includes a concave seat 24 fixed to the mounting plate 13. A lead screw 25 is mounted within the concave seat 24 via bearings. Guide rods 27 are arranged parallel to each other on both sides of the lead screw, forming a stable transmission and guiding structure. A sliding seat 26 is threaded onto the lead screw 25. This sliding seat 26 is movably sleeved on the guide rods 27 and can slide smoothly along the rod body.

[0034] The stretching roller 23 is mounted between two sets of sliding seats 26 via bearings. The sliding seats 26 pass through the mounting plate 13, which has a through groove to provide vertical movement space for the sliding seats 26. A motor (not shown) is mounted at the end of the concave seat 24, and its output shaft passes through the concave seat and is connected to the lead screw 25. When the motor drives the lead screw 25 to rotate, the threaded transmission drives the sliding seat 26 to move up and down along the guide rod 27, thereby adjusting the relative distance between the stretching roller 23 and the fixed roller 22 to meet the requirements of different film stretching processes.

[0035] In this application, a second transmission component is provided between the roller shafts of the two sets of stretching rollers 23, located within the gap space. This component includes a meshing gear set or a synchronous belt pulley mechanism, used to drive the two sets of stretching rollers 23 to rotate synchronously in the same direction and at the same speed. Simultaneously, the transmission speeds of the stretching rollers 23 and the fixed roller 22 are differentiated. The difference in linear velocity between the two rollers is used to apply controllable tension to the film, thereby achieving the directional stretching process requirements of the film and ensuring that the film reaches the predetermined thickness and mechanical properties. It should be noted that using the speed difference between the stretching rollers 23 and the fixed roller 22 to achieve the film stretching function is prior art and will not be described further here.

[0036] It should be noted that a displacement sensor can be installed on one side of the concave seat 24 near one end, with its contact end in contact with the upper surface of the sliding seat 26, to detect the displacement of the sliding seat 26 in real time, thereby accurately feeding back the change in the distance between the stretching roller 23 and the fixed roller 22.

[0037] like Figure 3 and Figures 6-8 As shown, a top plate 17 is fixedly installed below the top of the inner wall of the housing 12. The top plate 17 and the top of the inner wall of the housing 12 form an accommodating space for arranging the air supply assembly 3. (This embodiment only shows the air supply assembly 3 installed on the top plate 17; the corresponding components of the bracket 11 can be adapted as needed.) Its specific structure is as follows:

[0038] The air supply assembly 3 includes at least two sets of air supply sections. Each set of air supply sections is supported by a support plate 31, which is fixed to the top plate 17 by fasteners. Two sets of guide rails 333 are arranged parallel to each other on the surface of the support plate 31. The movable plate 33 is slidably adapted to the guide rails 333 by a slider 332, and can move linearly along the guide rail direction. The movable plate 33 has multiple sets of waist grooves 331 in an outwardly diffused shape. A pitch-changing unit is connected to the waist groove 331 by a pulley 342. The pitch-changing unit is embedded in the waist groove 331 by the pulley 342, and can be adjusted radially along the groove. The pitch-changing unit includes an L-shaped moving rod 34, in which a pulley 342 is rotatably connected to the moving rod 34. The right-angle end of the moving rod 34 is fitted with an air guide head 35 by a bolt / nut assembly, forming a hot air output terminal.

[0039] To constrain the motion trajectory of the pitch unit, a limiting part is installed on the support plate 31. The limiting part includes two sets of slide rails 32 that are fixedly installed on the support plate 31 and arranged in parallel perpendicular to the direction of the guide rail 333. The bottom of the moving rod 34 is correspondingly fixed to the slider 341, forming a sliding pair in the orthogonal direction with the slide rail 32. This ensures that the pitch unit can accurately move along the preset trajectory under the guidance of the waist groove 331 and the constraint of the slide rail 32. Multiple sets of air guide heads 35 are connected through the diversion pipe 36. The diversion pipe 36 is provided with a single air inlet port for centralized access to the hot air source.

[0040] The support plate 31 is equipped with a moving unit that drives multiple sets of pitch-changing units to synchronously change pitch. The concave seat 313 of the moving unit is fixed to the support plate 31 by bolts. The lead screw 314 is mounted on the concave seat 313 through a deep groove ball bearing (or a suitable bearing type). The movable seat 315 is threadedly engaged with the lead screw 314 and rigidly connected to the upper surface of the movable plate 33 by bolts. One end of the movable plate 33 is connected to the concave seat 313 through a guide rail slider pair (not shown in the figure, a slider structure adapted to the guide rail 333 can be used). The other end relies on the cooperation of the guide rail 333 and the slider 332 to form a double-end supported sliding guide structure with the support plate 31, ensuring the stability of the movable plate 33 during translation.

[0041] A drive unit 311 (which, according to the diagram, can be adapted to power sources such as motors and servo motors) is fixedly mounted on the support plate 31. The output shaft of the drive unit 311 is fixedly connected to the drive wheel of the transmission unit 312. The transmission unit 312 adopts a belt pulley transmission structure, and the driven wheel is coaxially connected to one end of the lead screw 314. When the drive unit 311 operates, it transmits power to the lead screw 314 through the belt pulley transmission unit 312, driving the lead screw 314 to rotate. This, in turn, drives the movable seat 315 to move along the lead screw axis through the threaded pair, pulling the movable plate 33 to slide along the guide rail 333. At this time, the waist groove 331 and the slide rail 32 work together to force the variable pitch unit to slide radially along the waist groove 331, ultimately realizing that multiple sets of air guide heads 35 move closer or further away simultaneously, adapting to the heating process requirements of films with different widths.

[0042] In order to supply hot air to the air inlet port of the splitter 36, such as Figure 6 As shown, a heating component 4 is embedded in the housing 12. The heating component 4 includes a mounting cover 41 fixedly installed on the housing 12. An opening slot (not shown in the figure) adapted to the mounting cover 41 is opened on the housing 12. A heating box 42 is installed inside the mounting cover 41. A heating wire (shown in the figure) is provided near the upper end of the heating box 42. At least two sets of fans 43 are embedded at the bottom of the heating box 42 and are adapted to the air supply component 3. The fans 43 are connected to the air guide pipe 44. The air guide pipe 44 is connected to the diversion pipe 36 through a flexible hose. The flexible hose is made of silicone. Utilizing the high temperature resistance and good flexibility of silicone, it adapts to the displacement requirements of the air supply component 3 when the pitch changes, ensuring stable hot air transmission.

[0043] To accurately measure the spacing between the outermost air guide heads 35 in multiple pitch control units, such as Figures 7-8 As shown (in) Figure 8 For example, a base 37 is fixedly installed on the side of the moving rod 34 of the rightmost pitch-changing unit, and a laser rangefinder 38 is integrated on the base 37. Correspondingly, a base 39 is fixedly connected to the side of the moving rod 34 of the leftmost pitch-changing unit, and a receiver 310 adapted to the laser rangefinder 38 is installed on the base 39. When multiple sets of air guides 35 move synchronously with the pitch-changing unit, the laser beam emitted by the laser rangefinder 38 is received by the receiver 310. The actual distance between the two air guides 35 is obtained in real time by measuring the propagation time difference of the light signal, so as to adapt to the use of films of different widths.

[0044] It should be noted that a PLC controller is installed on the bracket 11. The PLC controller performs coordinated control of the various devices in the device through a preset program.

[0045] Working Principle: During operation, the film enters through the feed port 14 on one side of the housing 12 and is stretched by the stretching assembly 2. Two sets of fixed parts of the stretching assembly 2 are distributed along the film conveying direction on both sides inside the housing 12. The fixed roller 22 rotates synchronously via the first transmission assembly, ensuring stable film conveying. The stretching roller 23 above the fixed roller 22 is also driven to rotate synchronously by the second transmission assembly, but has a different linear velocity than the fixed roller 22. This velocity difference applies controllable tension to the film, achieving directional stretching to reach the predetermined thickness and mechanical properties. The adjustment unit drives the lead screw 25 to rotate via a motor, causing the sliding seat 26 to move along the guide rod 27, precisely adjusting the distance between the stretching roller 23 and the fixed roller 22 to adapt to the stretching requirements of different films. A displacement sensor monitors the distance change in real time and provides feedback, ensuring process accuracy.

[0046] During the film stretching process, the air supply assembly 3 heats the film to improve its stretching properties. The fan 43 of the heating assembly 4 sends air into the heating chamber 42, where it is heated by heating wires and then delivered through the air duct 44 and silicone hose to the distribution pipe 36. Multiple sets of air guides 35 then blow air evenly onto the film. The moving unit of the air supply section drives the lead screw 314 to rotate via the drive component 311 and the pulley transmission part 312, causing the movable plate 33 to slide along the guide rail 333. Combined with the constraint of the waist groove 331 and the slide rail 32, the synchronous pitch of the air guides 35 is achieved, adapting to the heating requirements of films of different widths. The laser range sensor 38 and the receiver 310 measure the distance between the outermost air guides 35 in real time, ensuring that hot air evenly covers the film boundary area. This solves the problem of uneven heating at the film boundary in traditional devices, improving overall heating efficiency and product quality.

[0047] The above description is merely a preferred embodiment of the present utility model and is not intended to limit the present utility model in any way. Although the present utility model has been disclosed above with reference to a preferred embodiment, it is not intended to limit the present utility model. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present utility model. Any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present utility model without departing from the scope of the present utility model shall still fall within the scope of the present utility model.

Claims

1. A film stretching device, characterized in that: include A bracket (11) on which a housing (12) is mounted; Two sets of fixed seats (21) are mounted on the bracket (11), and a fixed roller (22) is mounted on the bearing between the two sets of fixed seats (21). A tension roller (23) is correspondingly arranged above the fixed roller (22). An air supply assembly (3) is installed inside a housing (12). The air supply assembly (3) includes at least two sets of air supply sections. Each air supply section includes a support plate (31) installed on a top plate (17). Two sets of guide rails (333) are arranged on the surface of the support plate (31). A movable plate (33) is connected to the guide rails (333) via a slider (332). The movable plate (33) has multiple sets of waist grooves (331) in an outwardly diffused shape. The waist grooves (331) are connected to a pitch unit via a pulley (342). The pitch unit includes a moving rod (34). A guide head (35) is mounted on the right-angle end of the moving rod (34). Multiple sets of guide heads (35) are connected through a split pipe (36). The split pipe (36) has a single air inlet port. The support plate (31) is equipped with a limiting part for constraining the motion trajectory of the pitch unit, and the support plate (31) is equipped with a moving unit that drives multiple sets of pitch units to change pitch synchronously.

2. The film stretching device according to claim 1, characterized in that: The limiting part includes two sets of slide rails (32) that are fixedly installed on the bearing plate (31) and arranged in parallel with the direction of the guide rail (333), and the bottom of the moving rod (34) is correspondingly fixed to the second slider (341).

3. The film stretching device according to claim 2, characterized in that: The concave seat 2 (313) of the moving unit is fixed to the bearing plate (31) by bolts. The lead screw 2 (314) is mounted on the concave seat 2 (313) through a bearing. The movable seat (315) is threadedly engaged with the lead screw 2 (314) and rigidly connected to the upper surface of the movable plate (33) by bolts. One end of the movable plate (33) is connected to the concave seat 2 (313) through a guide rail slider pair, and the other end relies on the cooperation of the guide rail (333) and the slider 1 (332).

4. A film stretching device according to claim 2, characterized in that: The drive component (311) is fixedly installed on the bearing plate (31). The output shaft of the drive component (311) is fixedly connected to the drive wheel of the transmission part (312). The transmission part (312) adopts a belt pulley transmission structure, and the driven wheel is coaxially connected to one end of the lead screw (314).

5. A film stretching device according to claim 1, characterized in that: The housing (12) is fitted with a heating component (4), which includes a mounting cover (41) installed on the housing (12). The housing (12) has an opening slot adapted to the mounting cover (41), and a heating box (42) is installed inside the mounting cover (41). A heating wire is provided near the upper end of the heating box (42), and at least two sets of fans (43) are embedded at the bottom of the heating box (42) for use with the air supply component (3). The fans (43) are connected to the air guide pipe (44), and the air guide pipe (44) is connected to the diversion pipe (36) through a flexible hose made of silicone.

6. A film stretching apparatus according to claim 2, characterized in that: A base (37) is mounted on the side of the moving rod (34) of the rightmost pitch unit. A laser rangefinder (38) is integrated on the base (37). A base (39) is fixedly connected to the side of the moving rod (34) of the leftmost pitch unit. A receiver (310) adapted to the laser rangefinder (38) is mounted on the base (39).

7. A film stretching apparatus according to claim 1, characterized in that: A PLC controller is installed on the bracket (11).

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