A solvent resistant label stretch forming apparatus

Abstract

The present application relates to a kind of solvent-resistant label stretch forming device in the field of label processing device, heating is carried out when the first heating roller is stretched in label base film, so that label base film is stretched more uniformly, the surface temperature of the first heating roller is monitored using contact temperature sensor, the temperature of heat medium injected into multi-channel rotary joint is controlled, and the temperature of heat medium injected into feeding inlet and flowed out of discharging outlet is detected respectively, to judge the heat exchange efficiency of heat medium in the first heating roller, further judge whether scale exists in the first heating roller, and in the early stage of scale formation, use pulse flow to break, finally use collection unit to capture and concentrate scale fragments, reduce the risk of multi-channel rotary joint blockage, discard the complex scale cleaning device set in the heating roller in prior art, increase its reliability, reduce the maintenance cost of heating roller.

Description

Technical Field

[0001] This invention relates to label forming processes, and in particular to a stretch forming apparatus for solvent-resistant labels used in the field of label processing equipment. Background Technology

[0002] Label substrates are divided into two types: paper and film. Among them, film substrates are mainly plastic films such as PVC, PET, PP, and PC. With the increasing awareness of environmental protection, the recycling and reuse of the above-mentioned plastic films has gradually become more common. In label production, the stretching process is a key step in transforming ordinary films into high-performance label substrates through molecular orientation and recombination. In the stretching process, the temperature maintenance of the heating rollers that hot-press the film is the most critical equipment. The temperature control of recycled plastic films during the processing needs to be more precise.

[0003] Chinese patent CN220534724U discloses a thickness adjustment device for cast film, which includes a cleaning device for cleaning scale on the inner wall of a cooling roller. The cleaning device includes a scraper that is movably connected to the inner wall of the cooling roller. An armature is installed on the side of the scraper away from the inner wall of the cooling roller. An electromagnet is arranged next to the cooling roller. When the electromagnet is energized, it can attract the armature, thereby making the scraper adhere to the inner wall of the cooling roller. This ensures that the scraper position remains unchanged during the rotation of the cooling roller, thus scraping away the scale on the inner wall of the cooling roller and ensuring uniform temperature on the outer wall of the cooling roller.

[0004] Chinese patent CN216914597U discloses a cooling roller for film forming. A fixed tube plate is arranged along the axial direction of the hollow roller body and a scraper is arranged to contact the inner wall of the hollow roller body to scrape off the scale on the inner wall of the hollow roller body. During the operation of the roller body, the scale and dirt that have adhered to the inner wall of the roller body during long-term use are scraped off, preventing uneven heat exchange of the roller body caused by scale and dirt. This helps to further enhance the temperature uniformity of the hollow roller body and improve the yield of the produced film.

[0005] Most label materials have a glass transition temperature below 100 degrees Celsius. Steam and hot water can easily meet the stretching requirements of label materials. Steam condensation has high and uniform heat release efficiency, making it particularly suitable for wide-width heating rollers. This results in more uniform heating of the label material, leading to more uniform and consistent subsequent stretching and improved stretching effect. Existing heating and cooling rollers using steam or hot water as the heat medium have dedicated cleaning devices in the cooling channels to remove scale generated during the use of the heat medium. However, such cleaning devices increase the complexity of the internal structure of the heating or cooling rollers, reduce their reliability, and increase their maintenance costs. Summary of the Invention

[0006] The technical problem that this invention aims to solve in view of the above-mentioned prior art is that the existing scale removal structures of heating rollers and cooling rollers result in complex inner wall structures, reduce their reliability, and increase their maintenance costs.

[0007] To solve the above problems, the present invention provides a stretch forming device for solvent-resistant labels, including a feeding roller and a receiving roller that are matched with each other. The heating roller includes a heating roller body, and a heat medium channel is opened in the heating roller body. The heat medium channel is connected to the channel of the multi-channel rotary joint. A collection unit is provided at one end of the heat medium channel near the discharge port.

[0008] The collection unit includes a matching outer shell and an inner liner, with the inner liner inserted inside the outer shell. A rear cover is fixedly connected between the outer shell and the inner liner. A matching solenoid valve is fixedly connected to the opening at the end of the inner liner away from the multi-channel rotary joint. A magnetic sealing plate matching the outer shell is fitted on the outer side of the inner liner. A compression spring is fixedly connected between the magnetic sealing plate and the rear cover. An electromagnetic ring is fixedly connected to the outer wall of the inner liner. With the electromagnetic ring as the dividing line, the end of the inner liner away from the multi-channel rotary joint is a solid plate, and the end of the inner liner near the multi-channel rotary joint is a mesh structure. Multiple capture units are fixedly connected to the inner wall of the outer shell and the mesh structure of the inner liner. The multiple capture units overlap to form a three-dimensional spatial structure.

[0009] In the above-mentioned stretch forming process of solvent-resistant labels, the scale is broken up in the early stage of scale formation using pulse flow, and finally the scale fragments are captured and concentrated by the collection unit, reducing the risk of blockage of the multi-channel rotary joint.

[0010] As a further improvement of this application, an infrared temperature sensor is provided on one side of the heating roller, and the infrared temperature sensor is directly facing the contact position between the label base film and the heating roller.

[0011] As a further improvement of this application, an insulation chamber is provided on the outer side of the front roller assembly, and the label base film passes through the insulation chamber. The insulation chamber is made of a low thermal conductivity material to shield the working environment of the front roller assembly, prevent a large amount of heat from heating the label base film from escaping, and reduce energy consumption.

[0012] As a further improvement of this application, the ends of the outer shell and the magnetic sealing plate that are close to each other are matched with slopes to reduce the impact on the flow of heat medium.

[0013] As a further improvement of this application, an illumination unit is fixedly connected to the end of the electromagnetic ring away from the magnetic sealing plate, and a photosensitive unit matching the illumination unit is fixedly connected to the end of the rear cover near the electromagnetic ring. The capture unit is made of colorless and transparent material. After each pulse cleaning, the photosensitive unit and the illumination unit are activated. The multiple shells are judged to be saturated based on the illumination area and intensity received by the photosensitive unit, and the maintenance of the heating roller and the replacement of the collection unit are arranged in a reasonable manner.

[0014] As a further improvement of this application, the hot press roller can be selectively replaced with a second heating roller, which includes a matching pressure shell and a rotating shaft. The pressure shell and the rotating shaft are filled with a casting layer. A heat transfer pipe is embedded in the rotating shaft and the casting layer. Both ends of the heat transfer pipe are connected to a multi-channel rotary joint. Multiple heat-conducting units are embedded in the casting layer to conduct heat, making the overall heat distribution of the second heating roller more uniform and improving the heating effect on the label base film.

[0015] As a further improvement of this application, the heat-conducting unit is suspended in the liquid casting layer. The heat-conducting unit includes a core, and multiple heat-conducting fibers are fixedly connected to the outside of the core. The heat-conducting fibers are made of elastic material, and adjacent heat-conducting fibers are interlaced. On the one hand, the multiple heat-conducting fibers form a three-dimensional spatial structure, which allows the multiple heat-conducting units to maintain a certain distance from each other, so that the positions of the heat-conducting units are not too concentrated and do not affect the heat conduction effect of the heat-conducting units. On the other hand, the interlaced heat-conducting fibers can increase the overall heat conduction effect of the heating roller and increase the heating effect on the label base film.

[0016] In summary, using steam or hot water as the heat medium, the heating roller one heats the label base film during stretching, resulting in more uniform stretching. Simultaneously, a contact temperature sensor monitors the surface temperature of the heating roller one, controlling the temperature of the heat medium injected into the multi-channel rotary joint. The heat exchange efficiency of the heat medium within the heating roller one is determined by detecting the temperatures of the heat medium injected into and exiting the multi-channel rotary joint, thus identifying the presence of scale. In the early stages of scale formation, a pulsed flow is used to break up the scale, and a collection unit captures and concentrates the scale fragments, reducing the risk of blockage in the multi-channel rotary joint. This eliminates the need for the complex scale cleaning device inside the heating roller in existing technologies, increasing reliability and reducing maintenance costs. Improving the heat-pressing roller with a heat-conducting unit results in a more uniform overall heat distribution in the heating roller two, leading to better heating of the label base film. However, this method has a higher manufacturing cost than the heating roller one in the first embodiment, making it suitable for high-cost label base film processing. Attached Figure Description

[0017] Figure 1This is a schematic diagram of the structure of the solvent-resistant label stretching device according to the first embodiment of this application;

[0018] Figure 2 This is a simplified flow chart of the solvent-resistant label stretching process according to the first embodiment of this application;

[0019] Figure 3 This is a schematic diagram of the structure of the heating roller according to the first embodiment of this application;

[0020] Figure 4 This is a cross-sectional structural diagram of the heating roller according to the first embodiment of this application;

[0021] Figure 5 for Figure 4 Schematic diagram of the structure at point A;

[0022] Figure 6 This is a schematic diagram of the structure of the collection unit according to the first embodiment of this application;

[0023] Figure 7 This is a side cross-sectional view of the collection unit according to the first embodiment of this application;

[0024] Figure 8 This is a schematic diagram of the water flow structure of the collection unit when the heating roller of the first embodiment of this application is working normally;

[0025] Figure 9 This is a schematic diagram of the water flow structure of the collection unit during cleaning of the heating roller according to the first embodiment of this application;

[0026] Figure 10 This is a cross-sectional structural diagram of the heating roller according to the second embodiment of this application;

[0027] Figure 11 This is a schematic diagram of the structure of the heat-conducting unit according to the second embodiment of this application.

[0028] The following are the labels in the diagram: 1. Feeding roller, 2. Receiving roller, 3. Label base film, 4. Front roller group, 5. Rear roller group, 6. Insulation chamber, 7. Heating roller one, 701. Main body of heating roller one, 702. Heat medium channel, 8. Multi-channel rotary joint, 9. Feed port, 10. Discharge port, 11. Collection unit, 1101. Outer shell, 1102. Liner, 1103. Solenoid valve, 1104. Rear cover, 1105. Magnetic sealing plate, 1106. Photosensitive unit, 1107. Electromagnetic ring, 1108. Illumination unit, 1109. Compression spring, 1110. Capture unit, 12. Heating roller two, 1201. Pressure shell, 1202. Rotating shaft, 1203. Casting layer, 1204. Heat medium pipe, 13. Heat conduction unit, 1301. Core, 1302. Heat conduction fiber. Detailed Implementation

[0029] The two embodiments of this application will be described in detail below with reference to the accompanying drawings.

[0030] First implementation method:

[0031] Figure 1 - Figure 7 A solvent-resistant label stretch forming apparatus is shown, including a feeding roller 1 and a receiving roller 2 that are matched with each other. A front roller group 4 and a rear roller group 5 are arranged between the feeding roller 1 and the receiving roller 2. The front roller group 4 is located on the side of the rear roller group 5 close to the feeding roller 1. The front roller group 4 includes a pressure roller and a hot pressure roller. The hot pressure roller includes a heating roller 7. The rear roller group 5 includes a pair of pressure rollers of the same specifications as the pressure roller. One end of the heating roller 7 is fixedly connected to a multi-channel rotary joint 8. The multi-channel rotary joint 8 is fixedly connected to an inlet 9 and an outlet 10. Contact temperature sensors are arranged in the inlet 9 and the outlet 10. One end of the label base film 3 is fixedly connected to the feeding roller 1 and wound on the feeding roller 1. The other end of the label base film 3 is passed through the front roller group 4 and the rear roller group 5 in sequence and fixedly connected to the receiving roller 2. An infrared temperature sensor is arranged on one side of the heating roller 7, and the infrared temperature sensor is facing the contact position between the label base film 3 and the heating roller 7.

[0032] Heating roller 7 includes a heating roller body 701, a heat medium channel 702 is provided in the heating roller body 701, the heat medium channel 702 is connected to the channel of the multi-channel rotary joint 8, and a collection unit 11 is provided at one end of the heat medium channel 702 near the discharge port 10.

[0033] The collecting unit 11 includes a matching outer shell 1101 and an inner liner 1102, with the inner liner 1102 inserted inside the outer shell 1101. A rear cover 1104 is fixedly connected between the outer shell 1101 and the inner liner 1102. A matching solenoid valve 1103 is fixedly connected to the opening at one end of the inner liner 1102 away from the multi-channel rotary joint 8. A magnetic sealing plate 1105 matching the outer shell 1101 is fitted on the outer side of the inner liner 1102. The magnetic sealing plate 1105 and the rear cover 1104 are connected together. A compression spring 1109 is fixedly connected between them. An electromagnetic ring 1107 is fixedly connected to the outer wall of the inner liner 1102. With the electromagnetic ring 1107 as the dividing line, the end of the inner liner 1102 away from the multi-channel rotary joint 8 is a solid plate, and the end of the inner liner 1102 close to the multi-channel rotary joint 8 is a mesh structure. Multiple capture units 1110 are fixedly connected to the inner wall of the outer shell 1101 and the mesh structure of the inner liner 1102. The multiple capture units 1110 overlap each other to form a three-dimensional spatial structure.

[0034] The internal structure of the collection unit must be made of materials suitable for use in environments up to 200 degrees Celsius to reduce the possibility of premature failure due to high temperatures.

[0035] Its usage mainly includes the following steps:

[0036] S1. Pre-treatment: Assemble a solvent-resistant label stretching device, and fix one end of the label base film 3 to the feeding roller 1 and wind it onto the feeding roller 1. Pass the other end of the label base film 3 through the front roller group 4 and the rear roller group 5 in sequence and fix it onto the receiving roller 2. An infrared temperature sensor is set on one side of the heating roller 7, and the infrared temperature sensor is directly facing the contact position between the label base film 3 and the heating roller 7 to complete the pre-treatment work. In particular, the feeding roller 1, receiving roller 2, front roller group 4 and rear roller group 5 of this application all need to be set up with a frame to ensure their relative positions during normal operation. In addition, the feeding roller 1, receiving roller 2, front roller group 4 and rear roller group 5 need to be set up with a power mechanism to drive themselves to rotate at a preset speed. At the same time, in addition to the structure shown in the attached drawings, the multi-channel rotary joint 8 should also be equipped with necessary structures such as sealing. The above contents are all known technologies to those skilled in the art, so they are not disclosed in detail in this application. Those skilled in the art can reasonably set the above contents according to the existing technology and actual use requirements.

[0037] S2. Label stretching: The heating roller 7 is preheated by injecting heat medium into the feed inlet 9. An infrared temperature sensor detects the surface temperature of the heating roller 7. When the temperature of the heating roller 7 reaches the preset stretching temperature, the stretching process begins. The linear velocities of the front roller group 4 and the rear roller group 5 are set so that the ratio of their linear velocities is a preset stretching ratio. The temperature of the heat medium injected into the feed inlet 9 is adjusted in real-time based on the temperature detected by the infrared temperature sensor: if the detected temperature is lower than the preset temperature, the temperature of the injected heat medium is increased; if the detected temperature is higher than the preset temperature, the temperature of the injected heat medium is decreased. Simultaneously, based on the data collected by the contact temperature sensors inside the feed inlet 9 and the discharge outlet 10, the temperature difference of the heat medium after passing through the heating roller 7 is calculated in real time. When the temperature difference is lower than the threshold of the injected heat medium temperature, such as 1% (pre-set according to the material and processing requirements of the label base film 3), the heat medium is restricted by scale and cannot exchange heat with the heating roller 7 normally. It is necessary to clean the heating roller 7, switch the feed inlet 9 to pulsed heat medium flow, use pulsed heat medium to clean the scale, restore the normal heat exchange function of the heating roller 7, so that the label is heated more evenly and stretched more evenly when it is stretched.

[0038] S3, winding for later use: The stretched label base film 3 is wound onto the take-up roller 2 for later use.

[0039] The preset temperature and preset stretch ratio are related to the specific material and processing requirements of the label base film 3, and need to be set by technicians according to the actual situation.

[0040] A heat preservation chamber 6 is fitted on the outer side of the front roller assembly 4. The label base film 3 passes through the heat preservation chamber 6. The heat preservation chamber 6 is made of a low thermal conductivity material to shield the working environment of the front roller assembly 4, prevent the heat from the label base film 3 from escaping in large quantities, and reduce energy consumption.

[0041] Please see Figure 8 When the heating roller 7 is in normal working condition, the solenoid valve 1103 is in the open state, and the heat medium flows directly through the liner 1102 through the collection unit 11.

[0042] When the heating roller 7 is being cleaned using a pulse-type heat transfer medium, please refer to... Figure 9 When the feeding roller 1, receiving roller 2, front roller group 4, and rear roller group 5 stop rotating, the label base film 3 stops transporting, the solenoid valve 1103 closes, the solenoid ring 1107 is energized, and the magnetic sealing plate 1105 is attracted towards itself. The heat medium flows in through the gap between the outer shell 1101 and the inner liner 1102, and passes through the mesh structure of multiple capture units 1110 and the inner liner 1102 in sequence to capture the debris mixed in the heat medium that has been broken by the pulse heat medium, so as to avoid blockage in the heat medium channel 702 or the collection unit 11. This makes it less likely to affect the hot pressing of the label. During the pulse cleaning process, the label base film 3 stops moving and the position of the label base film in contact with the heating roller 7 will be relatively fixed. When the pulse heat medium causes a large temperature fluctuation in the heating roller 7, it is not likely to cause a large-scale quality degradation of the label base film 3.

[0043] In addition, when steam or hot water is used as the heat medium in the heating roller, the water usually needs to be softened to significantly reduce the rate of scale formation. Therefore, in practical applications, there is no need to perform routine pulsed heat medium cleaning and maintenance on the heating roller 7, thus minimizing the impact on the continuity of label base film 3 processing.

[0044] The ends of the outer casing 1101 and the magnetic sealing plate 1105 that are close to each other are matched with slopes to reduce the impact on the flow of heat medium.

[0045] An illumination unit 1108 is fixedly connected to the end of the electromagnetic ring 1107 away from the magnetic sealing plate 1105. A photosensitive unit 1106, matching the illumination unit 1108, is fixedly connected to the end of the rear cover 1104 near the electromagnetic ring 1107. The capturing unit 1110 is made of colorless and transparent material. After each pulse cleaning, the photosensitive unit 1106 and the illumination unit 1108 are activated. When the amount of debris captured by the capturing unit 1110 increases, its light transmittance decreases, resulting in a weakening of the light signal received by the photosensitive unit 1106. By detecting the change in the intensity of the light signal, the saturation level of the collecting unit 11 can be determined, and the maintenance of the heating roller 7 and the replacement of the collecting unit 11 can be arranged accordingly.

[0046] In this embodiment, steam or hot water is used as the heat medium. The heating roller 7 heats the label base film 3 during stretching, making the stretching of the label base film 3 more uniform. At the same time, an infrared temperature sensor monitors the surface temperature of the heating roller 7 and controls the temperature of the heat medium injected into the multi-channel rotary joint 8. The heat exchange efficiency of the heat medium inside the heating roller 7 is determined by detecting the temperature of the heat medium injected into the feed port 9 and the temperature of the heat medium flowing out of the discharge port 10, thereby determining whether there is scale inside the heating roller 7. In the early stage of scale formation, a pulse flow is used to break it up. Finally, the collection unit 11 captures and concentrates the scale fragments, reducing the risk of blockage of the multi-channel rotary joint 8.

[0047] Second implementation method:

[0048] Figure 10 - Figure 11 Another type of hot press roller shown can be selectively replaced by a second heating roller 12. The second heating roller 12 includes a pressure shell 1201 and a rotating shaft 1202 that are matched with each other. The pressure shell 1201 and the rotating shaft 1202 are filled with a casting layer 1203. A heat medium pipe 1204 is embedded in the rotating shaft 1202 and the casting layer 1203. Both ends of the heat medium pipe 1204 are connected to a multi-channel rotary joint 8. Multiple heat-conducting units 13 are embedded in the casting layer 1203.

[0049] The heat-conducting unit 13 is suspended within the liquid casting layer 1203. The heat-conducting unit 13 includes a core 1301, and multiple heat-conducting fibers 1302 are fixedly connected to the outside of the core 1301. The heat-conducting fibers 1302 are made of elastic material. Adjacent heat-conducting fibers 1302 are interlaced. On the one hand, the multiple heat-conducting fibers 1302 form a three-dimensional spatial structure, which allows the multiple heat-conducting units 13 to maintain a certain distance from each other, so that the positions of the heat-conducting units 13 are not too concentrated and do not affect the heat conduction effect of the heat-conducting units 13. On the other hand, the interlaced heat-conducting fibers 1302 can increase the overall heat conduction effect of the heating roller 12 and increase the heating effect on the label base film 3.

[0050] All parts of the second heating roller 12 are made of high thermal conductivity materials. The casting layer 1203 is made of high temperature resistant and high thermal conductivity colloid, such as silicone modified epoxy resin, which can withstand continuous immersion in 140°C steam and is suitable for the processing environment of this application. During the production of the second heating roller 12, the pressure shell 1201 and the rotating shaft 1202 are fixed by a molding mold. Then, a mixture of liquid casting layer 1203 and heat-conducting unit 13 is injected into the gap between the pressure shell 1201 and the rotating shaft 1202. After curing, the mixture is demolded to form the second heating roller 12. Compared with the first embodiment, in this embodiment, the heat-conducting unit 13 inside the hot press roller is used for heat conduction, which makes the heat distribution of the second heating roller 12 more uniform and the heating effect on the label base film 3 better. However, the manufacturing cost is higher than that of the first heating roller 7 in the first embodiment, and it is suitable for processing high-cost label base films 3. In light of current practical needs, the above-described embodiments adopted in this application are not limited to these. Any changes made within the scope of knowledge possessed by those skilled in the art without departing from the concept of this application still fall within the protection scope of this invention.

Claims

1. A stretch forming apparatus for solvent-resistant labels, comprising a feeding roller (1) and a receiving roller (2) that are matched with each other, wherein a front roller group (4) and a rear roller group (5) are arranged between the feeding roller (1) and the receiving roller (2), the front roller group (4) is located on the side of the rear roller group (5) close to the feeding roller (1), the front roller group (4) includes a pressure roller and a hot pressure roller, the hot pressure roller includes a heating roller (7), one end of the heating roller (7) is fixedly connected to a multi-channel rotary joint (8), and the multi-channel rotary joint (8) is fixedly connected to an inlet (9) and an outlet (10), characterized in that: The heating roller (7) includes a heating roller body (701), a heat medium channel (702) is provided in the heating roller body (701), the heat medium channel (702) is connected to the channel of the multi-channel rotary joint (8), and a collection unit (11) is provided at one end of the heat medium channel (702) near the discharge port (10). The collecting unit (11) includes a matching outer shell (1101) and an inner liner (1102), with the inner liner (1102) inserted inside the outer shell (1101). A rear cover (1104) is fixedly connected between the outer shell (1101) and the inner liner (1102). A matching solenoid valve (1103) is fixedly connected to the opening of the inner liner (1102) away from the multi-channel rotary joint (8). A magnetic sealing plate (1105) matching the outer shell (1101) is sleeved on the outside of the inner liner (1102). The magnetic sealing plate (1105) and the rear cover (1104) are connected to each other. A compression spring (1109) is fixedly connected between 104), and an electromagnetic ring (1107) is fixedly connected to the outer wall of the inner liner (1102). With the electromagnetic ring (1107) as the dividing line, the end of the inner liner (1102) away from the multi-channel rotary joint (8) is a solid plate, and the end of the inner liner (1102) close to the multi-channel rotary joint (8) is a mesh structure. Multiple capture units (1110) are fixedly connected to the inner wall of the outer shell (1101) and the mesh structure of the inner liner (1102). The multiple capture units (1110) overlap each other to form a three-dimensional spatial structure. By detecting the temperature of the heat medium injected at the feed inlet (9) and the heat medium flowing out at the discharge outlet (10), the heat exchange efficiency of the heat medium in the heating roller (7) is determined, and then it is determined whether there is scale in the heating roller (7). In the early stage of scale formation, it is broken up by pulse flow. When the heating roller (7) is in normal working state, the solenoid valve (1103) is in the open state. When the heating roller (7) is cleaned by pulse flow, the solenoid valve (1103) is closed. The electromagnetic ring (1107) is energized and the magnetic sealing plate (1105) is attracted towards itself. The heat medium flows in through the gap between the outer shell (1101) and the inner lining (1102) and passes through the mesh structure of multiple capture units (1110) and the inner lining (1102) in sequence to capture the debris mixed in the heat medium that is broken up by the pulse flow.

2. The stretch forming apparatus for solvent-resistant labels according to claim 1, characterized in that: The inlet (9) and outlet (10) are equipped with contact temperature sensors. One end of the label base film (3) is fixedly connected to the feeding roller (1) and wound on the feeding roller (1). The other end of the label base film (3) is passed through the front roller group (4) and the rear roller group (5) in sequence and fixedly connected to the receiving roller (2).

3. The stretch forming apparatus for solvent-resistant labels according to claim 2, characterized in that: An infrared temperature sensor is provided on one side of the heating roller (7), and the infrared temperature sensor is directly opposite the contact position between the label base film (3) and the heating roller (7).

4. The stretch forming apparatus for solvent-resistant labels according to claim 2, characterized in that: The front roller assembly (4) is fitted with a heat preservation chamber (6) on its outer side, and the label base film (3) passes through the heat preservation chamber (6). The heat preservation chamber (6) is made of a low thermal conductivity material.

5. The stretch forming apparatus for solvent-resistant labels according to claim 1, characterized in that: The outer shell (1101) and the magnetic sealing plate (1105) are adjacent to each other at one end, which are mutually matched inclined surfaces.

6. The stretch forming apparatus for solvent-resistant labels according to claim 1, characterized in that: The electromagnetic ring (1107) is fixedly connected to a light-emitting unit (1108) at the end away from the magnetic sealing plate (1105). The back cover (1104) is fixedly connected to a photosensitive unit (1106) that matches the light-emitting unit (1108) at the end near the electromagnetic ring (1107). The capturing unit (1110) is made of colorless and transparent material.

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