Film peeling device and film peeling method

Abstract

This invention provides a film peeling device that prevents the peeled film from re-adhering to a substrate film or from dissolving film components in a cleaning solution, thus reducing peeling ability. The film peeling device of this invention peels the film from a film-bearing membrane having a film on at least one side of a substrate film. The device comprises: a cleaning tank; a supply device for supplying cleaning solution to the cleaning tank; a conveying device for conveying the film-bearing membrane longitudinally through the cleaning tank; a suction box disposed within the cleaning tank, surrounding a portion of the conveying path of the film-bearing membrane with gaps allowing the membrane to pass through; a peeling mechanism disposed within the suction box for peeling the film from the film-bearing membrane; and a discharge device for discharging the cleaning solution and the peeled film from the suction box outside the cleaning tank.

Description

[Technical Field]

[0001] The present invention relates to a film peeling device and a film peeling method that can efficiently remove the film from the surface of a thermoplastic resin film. [Previous Technology]

[0002] Plastics are used in various fields, but on the other hand, they are considered a cause of marine pollution such as microplastics, making it urgent to reduce the environmental burden caused by plastics. Furthermore, in recent years, due to the evolution of the Internet of Things (IoT), electronic devices such as central processing units (CPUs) in computers or smartphones have increased. Consequently, the number of multilayer ceramic capacitors (MLCCs) required to drive these electronic devices has also increased dramatically. A typical manufacturing method for MLCCs includes the following steps: using a release film with a release layer formed on a plastic substrate film as a carrier; forming a ceramic green sheet layer on the release film; and peeling off the ceramic green sheet layer to produce a ceramic green sheet. In these steps, the release film after peeling off the ceramic green sheet is discarded as a useless material.

[0003] That is, the rapid increase in the number of MLCCs manufactured in recent years has led to an increase in the amount of release films as waste, which has become an environmental problem, and measures to reuse the substrate film are becoming increasingly active. In order to reuse the waste release film, it is only necessary to remelt and form a film after recycling / crushing / making it into a resin wafer to obtain a recycled film. However, from the point of view of release properties, the composition of the release layer contained in the release film is generally different from the composition of the substrate film. Therefore, when the release film with the release layer is directly remelted to make a recycled film, the components of the release layer exist as foreign matter, so it is impossible to achieve stable film formation. In Patent Document 1, as a method for removing the release components from the self-release film, the following method is disclosed: using a release film in which a water-soluble resin layer is formed between the substrate film and the release layer, immersing it in a warm water bath for more than 2 seconds, and then using a brush roller to sweep across the surface of the release film to peel off the release layer. [Prior Art Documents] [Patent Documents]

[0004] Patent Document 1: Japanese Patent Application Publication No. 2004-363140 [Summary of the Invention]

[0005] [The problem the invention aims to solve]

[0006] However, the film peeling method disclosed in Patent Document 1 sometimes causes the following problems: the film peeled off by the brush roller is reattached to the release film during transport, and is transported to a later step, thus mixing into the recycled film or contaminating the rollers in the later step. Additionally, sometimes the following problems occur: the water-soluble resin peeled off by the brush roller is suspended in the warm water tank, dissolving in the warm water. As the peeling process continues, the resin concentration in the warm water increases, and the initial peeling ability cannot be maintained. The faster the film transport speed, the more pronounced these problems become. Therefore, to eliminate these problems, regular cleaning of the device or reducing the film transport speed and shortening the length of the film processed per step are required. Consequently, the peeling capacity per unit time decreases significantly, making efficient peeling impossible.

[0007] Therefore, the object of the present invention is to provide a film peeling apparatus and a film peeling method, wherein in a film peeling apparatus for a self-moving membrane, even if the amount of film peeled increases due to the passage of peeling processing time or an increase in membrane conveying speed, the peeled film is prevented from re-adhering to the substrate film, or from decreasing peeling ability due to at least a portion of the film components dissolving into the cleaning solution. [Means for Solving the Problem]

[0008] The coating peeling apparatus of the present invention, which solves the aforementioned problem, peels the coating from a film having a coating on at least one side of a substrate film. The coating peeling apparatus comprises: a cleaning tank; a supply device for supplying cleaning liquid to the cleaning tank; a conveying device for conveying the film with the coating in the longitudinal direction such that the film with the coating passes through the cleaning tank; a suction box disposed in the cleaning tank at least at its front end in contact with the film with the coating, surrounding a portion of the conveying path of the film with the coating through a gap; a peeling mechanism disposed in the suction box for peeling the coating from the film with the coating; and a discharge device for discharging the cleaning liquid and the peeled coating from the suction box outside the cleaning tank.

[0009] Preferably, the film peeling device of the present invention has a removal device for removing foreign matter from the discharge liquid, and the discharge liquid with foreign matter removed is supplied to the cleaning tank. Another aspect of the present invention, addressing the aforementioned problem, provides a film-peeling device for peeling a film from a substrate film having a film on at least one side. The film-peeling device comprises: two or more cleaning tanks arranged along the transport direction of the film-coated membrane; a supply device for supplying cleaning liquid to at least the cleaning tank located downstream in the transport direction; a transport device for transporting the film-coated membrane longitudinally, such that the film-coated membrane sequentially passes through each of the cleaning tanks; a suction box, at least its front end in contact with the film-coated membrane, disposed within each of the cleaning tanks, surrounding a portion of the transport path of the film-coated membrane with gaps allowing membrane passage; a peeling mechanism disposed within each suction box for peeling the film from the film-coated membrane; and a discharge device for discharging the cleaning liquid and the peeled film from each suction box outside the cleaning tanks. At least one of the discharge devices has a removal device for removing foreign matter from the discharge liquid, and supplies the discharge liquid with foreign matter removed to another cleaning tank located upstream of the cleaning tank including the discharge device in the conveying direction.

[0010] The coating peeling method of the present invention, which solves the aforementioned problem, peels the coating off a film having a coating on at least one side of a substrate film. In the coating peeling method, a cleaning liquid is supplied to a cleaning tank, and the film with the coating is conveyed along its length direction through the cleaning liquid. The film with the coating is introduced into a suction box disposed in the cleaning liquid and having a gap for the film to pass through. The film is peeled off in the suction box by a coating peeling mechanism, and the cleaning liquid and the peeled film in the suction box are discharged out of the cleaning tank.

[0011] Preferably, the coating removal method of the present invention involves, after removing foreign matter from the discharge liquid discharged from the suction box, supplying the discharge liquid with the foreign matter removed to the cleaning tank. Another aspect of the present invention for solving the aforementioned problem involves a coating peeling method for a coated film having a coating on at least one side of a substrate film. In this method, two or more cleaning tanks are arranged along the transport direction of the coated film. Cleaning fluid is supplied to at least the cleaning tank located downstream in the transport direction. The coated film is transported along its length, passing sequentially through the cleaning fluid in each of the cleaning tanks. The coated film is then introduced into a suction box, which has a gap allowing the film to pass through, located within the cleaning fluid of each of the cleaning tanks. The coating is peeled off in the suction box by a coating peeling mechanism. The cleaning fluid and the peeled coating are discharged from each suction box outside the cleaning tank. After removing foreign matter from the discharged fluid discharged from at least one suction box, the discharged fluid, from which the foreign matter has been removed, is supplied to another cleaning tank located upstream in the transport direction than the cleaning tank including the suction box.

[0012] Preferably, the coating peeling method of the present invention sets the discharge volume of the discharge liquid from the suction box such that the flow rate of the cleaning liquid at the gap where the coated membrane leaves the suction box is greater than the transport speed of the coated membrane. Next, the meanings of the terms used in the present invention will be explained.

[0013] The term "gap through which the membrane can pass" refers to both the gap through which the membrane with the coating passes and the gap through which the substrate membrane after the coating has been peeled off passes. The term "discharge liquid" refers to the cleaning liquid discharged from the suction box and the peeled coating. The term "foreign matter" refers to the coating after the coating has been peeled off from the membrane with the coating. [Effects of the Invention]

[0014] By means of the film peeling device and film peeling method of the present invention, when the film is peeled off from the surface of the film-coated membrane having a film on at least one side of the substrate film, the peeled film can be prevented from re-attaching to the substrate film, or the peeling ability can be reduced due to at least a portion of the film components dissolving into the cleaning solution.

Implementation Method

[0016] The inventors have made efforts to study methods that prevent the peeled film from re-attaching to the substrate film or from decreasing peeling ability due to at least a portion of the film components dissolving into the cleaning solution when peeling the film from the surface of a film having a film on at least one side of a substrate film. As a result, they have discovered the following method and apparatus for peeling the film from a film with a film.

[0017] Considering environmental impact, the coating of the membrane with a coating is preferably a coating containing a water-soluble resin. Among these, the water-soluble resin is preferably one of the following resins as its main component: a water-soluble polyester resin, a polyester amino formaldehyde resin, an acrylic resin, an ethylene ionomer resin, a polyvinyl alcohol resin, a polyvinylpyrrolidone resin, an ethylene-vinyl alcohol resin, or starch. The coating containing the water-soluble resin can be a monolayer containing the water-soluble resin, a laminate of two or more layers containing the water-soluble resin, or a laminate of layers containing the water-soluble resin and layers not containing the water-soluble resin.

[0018] Furthermore, as a coated membrane, a release membrane with a coated membrane is particularly preferred, wherein a portion of the coated membrane contains not only a water-soluble resin but also a release agent, thereby effectively exhibiting the effect of coating membrane peeling. The release agent referred to herein is a component that increases the contact angle of the coated membrane surface with water, i.e., reduces the surface energy of the coated membrane. Examples of release agents include thermosetting silicone resin compounds with dimethylsiloxane as the main backbone, or UV-curing silicone resin compounds that are cured by irradiation with ultraviolet (UV) light after being formulated with a photopolymerization initiator in an organopolysiloxane containing acrylonitrile or methacrylonitrile. Examples of other release agents include compounds with long-chain alkyl groups and compounds containing fluorine. The coated membrane may contain a mixture of water-soluble resin and a release agent, or may consist of a layer containing water-soluble resin and a layer containing a release agent. In the case of a laminated film, it is preferable to form a layer containing a water-soluble resin directly above the substrate film, and then form a layer containing a release agent on the outermost surface. The release agent is preferably a thermosetting silicone resin compound with a water-permeable dimethylsiloxane as its main backbone.

[0019] [First Embodiment] An ideal embodiment of the film peeling apparatus of the present invention will be described based on the drawings. Furthermore, the following description illustrates one embodiment of the present invention and is not limited thereto; various modifications can be made without departing from the spirit of the present invention.

[0020] FIG1 is a schematic diagram of the film peeling apparatus 101 according to the first embodiment of the present invention. First, the structure of the film peeling apparatus 101 of the present invention will be described. The film peeling apparatus 101 includes a roll-out device 4 for rolling out a film 1 with a film coating and a winding device 5 for winding a substrate film 2 after the film coating has been peeled off. In addition, the film peeling apparatus 101 includes a conveying device 9 for the film 1 with a film coating and the substrate film 2, a cleaning tank 15 for storing cleaning liquid 16, a peeling mechanism 19 for peeling off the film coating from the film 1 with its own film coating, a support roller 17 for the peeling mechanism 19, and a suction box 18 surrounding a portion of the conveying film and the peeling mechanism 19. In addition, the support roller 17 and the suction box 18 form an inlet opening 20 as a gap for the film 1 with the film coating to pass through and an outlet opening 21 as a gap for the substrate film 2 to pass through. The film peeling device 101 further includes: a cleaning fluid 16 in a suction box, a discharge pump 12 as a discharge device for discharging the peeled film, a liquid delivery device 13 as a supply device for supplying the cleaning fluid 16 to the cleaning tank 15, and a supply nozzle 14.

[0021] The method for peeling the film from the film-bearing membrane 1 using the film peeling device 101 configured as described above will be described. The film-bearing membrane 1 is formed on one side of the substrate membrane 2. First, the film-bearing membrane 1, which is wound in a roll on a predetermined paper tube or the like, is installed on the winding device 4. At this time, it is installed such that the film-bearing surface of the film-bearing membrane 1 is in contact with the peeling mechanism 19. Next, the front end of the film-bearing membrane 1 is pre-wound onto the paper tube of the winding device 5 and connected to the lead film passing through the membrane transport path by an appropriate means. The cleaning tank 15 is pre-filled with cleaning liquid 16. Then, while the conveying device 9 is operated to transport the membrane, the film is peeled off using the peeling mechanism 19, and the substrate membrane 2 is wound using the winding device 5. At this time, the cleaning liquid 16 and the film in the suction box 18 are suctioned and discharged using the discharge pump 12, and the cleaning liquid 16 is supplied to the cleaning tank 15 using the liquid delivery device 13 and the supply nozzle 14.

[0022] In order to stably transport the film 1 with the coating and the substrate film 2 after the coating has been peeled off, the conveying device 9 is preferably a structure capable of tension shearing, such as a structure in which a metal drive roller and a rubber roller hold the film. In addition, since the cleaning fluid 16 is likely to adhere to the conveying device 9, stainless steel or a surface-treated material is preferably used as a rust prevention measure.

[0023] The peeling mechanism 19 can be a resin plate or the like with a sharp tip that comes into direct contact with the conveyed film 1 with a coating. The peeling mechanism 19 is not limited to this; a metal plate with a sharp tip can be provided, or a resin or thin metal blade that presses against and flexes against the film 1 with a coating, like a blade. Alternatively, a mechanism that rotates a brush roller containing metal or resin in the same or opposite direction to the conveying direction can be used to make it come into direct contact with the coating surface of the film 1 with a coating. Alternatively, waste cloth or fabric can be used to press against the film 1 with a coating and wipe the film for peeling. Furthermore, in the film peeling device 101 of this embodiment, the film is peeled off by pressing the peeling mechanism 19 at the position of the support roller 17 supporting the film 1 with a coating. However, the film can also be peeled off by pressing the peeling mechanism 19 against the conveying film under tension at the free span position of the conveyed film 1 with a coating. The peeling mechanism 19 can be positioned such that the film 1 with the coating can be peeled off after being immersed in the cleaning solution 16 for a sufficient time, rather than being limited to the bottom of the cleaning tank 15 as shown in Figure 1. Furthermore, the peeling mechanism 19 can be positioned facing the coating surface of the film 1 with the coating, rather than being limited to the lower surface side as shown in Figure 1. Additionally, to allow the film of the rolled-up film 1 to be handled from either the inner or outer side of the roller, the winding device 4 is preferably a mechanism that can handle both upward and downward winding, allowing the film surface of the film 1 to be conveyed facing the peeling mechanism 19 by switching the winding direction of the film 1 with the coating.

[0024] The suction box 18 is a device for holding the peeled film and at least a portion of the film components dissolved and the cleaning solution 16a with increased film component concentration in a manner that prevents diffusion into the cleaning tank 15. While the film and cleaning solution 16a in the suction box 18 are being suctioned and discharged by the discharge pump 12, the film is peeled off, thereby preventing the film from re-adhering to the transported substrate film 2, or preventing the increase of film component concentration in the cleaning solution 16 in the cleaning tank 15. At this time, if the flow rate of the cleaning solution 16 flowing into the suction box 18 through the outlet opening 21 is low, the film or the cleaning solution 16a with high film component concentration in the suction box 18 may sometimes flow out from the outlet opening 21 due to the accompanying flow of the transported film. Therefore, the flow rate of the cleaning solution at the outlet opening 21 is preferably greater than the speed of the transported film, and more preferably more than 1.5 times. When it is difficult to measure the flow rate of the cleaning fluid at the outlet opening 21, it can be replaced by the shape of each opening, such as the inlet opening 20, the outlet opening 21, and the gap between the support roller 17 and the suction box 18, and the value calculated based on the discharge volume discharged by the discharge pump 12. The flow rate through each opening can be calculated based on the theoretical formula of pressure loss determined by the shape of each opening, and the flow rate can be calculated by dividing by the cross-sectional area of ​​each opening.

[0025] Furthermore, in Figure 1, the entire peeling mechanism 19 enters the suction box 18, but only the film peeled off by the peeling mechanism 19 needs to remain inside the suction box. Only the front end of the peeling mechanism 19 is located inside the suction box 18; the rest can extend outside the suction box 18. If the inlet opening 20 and outlet opening 21 are too small, they may sometimes come into contact with the membrane when the conveying membrane meanders or sways. Conversely, if they are too large, the flow rate at the outlet opening 21 will decrease, and the film or the cleaning solution 16a with a high concentration of film components inside the suction box 18 may easily flow out from the outlet opening 21 due to the accompanying flow of the conveying membrane. Therefore, it is preferable to minimize the degree of contact with the conveying membrane, which can be appropriately determined according to the degree of meandering or swaying of the conveying membrane. For example, the distance between the membrane at the opening and the suction box can be 3 mm to 20 mm.

[0026] Here, the structure of the suction box 18 will be described in detail using Figures 2 and 3. Figure 2 is a partial enlarged view of the periphery of the suction box 18 of the film peeling device of Figure 1, and Figure 3 is a view of Figure 2 viewed from the X direction (downstream direction) (the peeling mechanism 19 is not shown in Figures 2 and 3). The suction box 18 may contact the support roller 17 at both ends in the film width direction as shown in Figures 2 and 3, or a gap may be provided so that there is no contact. When there is no contact, the cleaning liquid also flows into the suction box 18 through the gap, so the flow rate through the outlet opening 21 is reduced. Therefore, the gap is preferably as small as possible, for example, the distance between the suction box 18 and the support roller 17 at the gap is preferably 0.5 mm to 10 mm. The material of the suction box 18 is not particularly limited, but it is preferably made of heat-resistant and rust-resistant metal or resin. When in contact with the support roller 17, it is preferable to make the material of the contact part as a material with sliding properties and low wear, such as polyacetal, polyamide, or polytetrafluoroethylene.

[0027] In addition, in FIG1, the suction box 18 and the support roller 17 together surround the conveying film and peeling mechanism 19, but the suction box 18 can also surround the conveying film and peeling mechanism 19 as a single unit. For example, FIG6 is a schematic diagram showing another embodiment of the present invention. As shown in this figure, a box-shaped suction box 18 can also be provided at the position of the free span of the conveyed film, and the film can pass through the inlet opening 20, which serves as a gap for the film 1 with the film coating to pass through, and the outlet opening 21, which serves as a gap for the substrate film 2 to pass through.

[0028] The size of the suction tank 18 is not particularly limited, but if it is too large, it will take time to suction and discharge the membrane floating inside, which will increase the dissolution of the membrane components and the concentration of the membrane components in the cleaning solution. The size of the suction tank 18 can be set such that the cleaning solution in the volume surrounded by the suction tank 18 can be discharged within 2 minutes by the discharge pump 12. As the discharge pump 12, a diaphragm pump or a gear pump can be used. In order to not only suction and discharge the cleaning solution 16 with a high concentration of membrane components, but also suction and discharge the membrane detached from the membrane 1 with its own membrane, a flexible hose pump that can stably deliver the slurry solution is preferred.

[0029] The supply nozzle 14 can be any nozzle such as a sprayer or a slit nozzle. When supplying the cleaning fluid 16 to the cleaning tank 15, it is preferable to supply it simultaneously with blowing the cleaning fluid 16a onto the substrate membrane 2 as shown in FIG. 1, so that even if a coating is re-attached to the substrate membrane 2, it can be washed away. However, it is also possible to supply the cleaning fluid 16 directly to the cleaning tank 15 without blowing it onto the substrate membrane 2 from the sprayer, nozzle, or piping. The liquid delivery device 13 can be a liquid delivery pump capable of delivering the cleaning fluid 16. The same pump used as the discharge pump 12 can be used as the liquid delivery pump.

[0030] The cleaning tank 15 is filled with cleaning fluid 16 and is used to bring the cleaning fluid 16 into contact with the surface of the rolled-up film 1 with the coated film. A heater (not shown) for heating the cleaning fluid 16 may also be included. The contact time between the coated film 1 and the cleaning fluid 16 before reaching the peeling mechanism 19 can be relatively long, preferably more than 2 seconds. To adjust the contact time, rollers may also be provided in the cleaning tank 15 to fold and transport the substrate film 2 within the cleaning tank 15.

[0031] The support roller 17 is a roller used to support the film 1 with the film on it when the film is peeled off by the peeling mechanism 19, and is preferably a smooth metal roller.

[0032] The winding device 4 is a device for winding out the film 1 with a coating. The film 1 with a coating, which is wound in a roll on a paper tube or the like, is fixed to a rotating shaft. The rotating shaft is connected to a powder clutch or the like, forming a structure that allows the film 1 with a coating to spin freely during winding.

[0033] The winding device 5 is a device for winding the substrate film 2. In order to prevent the substrate film 2 from loosening, the winding tension can be controlled, for example, by using a torque motor.

[0034] The higher the temperature of the cleaning solution 16, the faster the dissolution rate of the coating components. That is, in order to improve the cleaning effect, the temperature of the cleaning solution 16 is preferably 40°C or higher. In order to suppress the dimensional changes or planarity deterioration of the substrate film 2 caused by heat, the temperature of the cleaning solution 16 applied to the film 1 with the coating is preferably 150°C or lower. Therefore, the cleaning solution 16 is preferably between 40°C and 150°C. In addition, any solvent that can dissolve the coating components will have its effect, but in order to reduce the environmental impact, water is preferred. The cleaning solution 16 can be heated by a heat source such as a cartridge heater, or by heating the tank (not shown) storing the cleaning solution 16, but any means are acceptable as long as the cleaning solution 16 can be heated, and it is not limited to these. In order to spray the heated cleaning solution 16, the material of the supply nozzle 14 is preferably heat-resistant, preferably metal or heat-resistant resin.

[0035] In order to stably produce a recycled film after remelting the substrate film 2 after it has been peeled off from the film wound by the winding device 5, it is preferable to completely remove the cleaning liquid 16. A drying device (not shown) may also be provided between the supply nozzle 14 and the winding device 5. The drying device can be provided before winding and can be located before or after the drive device 9.

[0036] In addition, to confirm the quality of the substrate film 2 after the film has been peeled off, an inspection machine (not shown) can be installed before the winding device 5 to detect film residue or environmental foreign matter attached during the process. The inspection machine can be selected according to the properties of the substrate film 2, and it is preferable to use an inspection machine that utilizes transmitted light or reflected light. In addition, a marking device (not shown) for recording the location of film residue or environmental foreign matter attached during the process detected by the inspection machine can be installed between the inspection machine and the winding device 5. As long as the location of the object to be detected can be marked, the marking method can be any method such as pen, sticker, or laser. By marking the film residue or environmental foreign matter attached during the process, the part can be removed before remelting, thus making the recycled film more stable and preventing the quality of the recycled film from deteriorating.

[0037] [Second Embodiment] FIG4 is a schematic diagram of the film peeling apparatus 201 according to the second embodiment of the present invention. The film peeling apparatus 201 serves as a discharge device for the cleaning liquid 16a from the suction box 18 and the peeled film. In addition to the discharge pump 12, it is also equipped with a removal device 202, an adjustment valve 203, and a supply nozzle 14. In this embodiment, since the discharge liquid discharged from the discharge pump 12 is reused and supplied to the cleaning tank 15, the cost related to the cleaning liquid can be suppressed compared with the film peeling apparatus 101 of FIG1. ​​In addition, when reusing the discharge liquid, foreign matter is removed from the discharge liquid discharged from the discharge pump 12 by the removal device 202 and then supplied to the cleaning tank 15 via the supply nozzle 14, thereby suppressing the film from re-attaching to the substrate film 2.

[0038] The amount of recycled effluent discharged by the discharge pump 12 can be adjusted using the adjusting valve 203. At this time, the amount of fresh cleaning fluid 16, the same amount as the unreused effluent, can be supplied to the cleaning tank 15 via the supply nozzle 14 through the self-feeding device 13, thus maintaining a constant cleaning fluid volume in the cleaning tank 15. The more recycled effluent, the higher the concentration of the film-forming component in the cleaning fluid 16 within the cleaning tank 15, and the lower the peeling ability. Therefore, the amount of recycled effluent can be determined to meet the required peeling ability while simultaneously checking the peeling status of the substrate film 2.

[0039] The removal device 202 is a device for removing the membrane from the drained liquid, and can be a filter or a continuous centrifuge, etc. When using a filter, since the membrane components captured by the membrane dissolve into the cleaning liquid flowing in the filter, it causes an increase in the concentration of membrane components in the cleaning liquid supplied to the cleaning tank 15, so the filter is preferably replaced periodically. Except as described above, it is the same as the membrane stripping device 101 in FIG. 1, so the components common to the membrane stripping device 101 are omitted from the description.

[0040] [Third Embodiment] FIG5 is a schematic diagram of the film peeling device 301 according to the third embodiment of the present invention. The film peeling device 301 includes, between the winding device 4 and the winding device 5: a conveying device 9 and a conveying device 9' for the film 1 with film and the substrate film 2; a cleaning tank 15 and a cleaning tank 15' for storing cleaning liquid 16 and cleaning liquid 16' respectively; a peeling mechanism 19 and a peeling mechanism 19' for peeling off the film 1 with film; a support roller 17 and a support roller 17'; a suction box 18 and a suction box 18' for surrounding a portion of the conveying film and the peeling mechanism 19 and the peeling mechanism 19' respectively; an inlet opening 20 and an inlet opening 20' for the film 1 with film to pass through; an outlet opening 21 and an outlet opening 21' for the substrate film 2 to pass through; a discharge pump 12 and a discharge pump 12' for discharging the cleaning liquid 16 and cleaning liquid 16' and the peeled film from the suction box; and a supply nozzle 14 and a supply nozzle 14'. Furthermore, the support roller 17' and the suction box 18' form an inlet opening 20' and an outlet opening 21' that serve as a gap for the membrane 1 with the coated film to pass through, and the support roller 17 and the suction box 18 form an inlet opening 20 that serves as a gap for the membrane 1 with the coated film to pass through and an outlet opening 21 that serves as a gap for the substrate membrane 2 to pass through.

[0041] In this embodiment, the effluent discharged from the downstream cleaning tank 15 by the discharge pump 12 is reused and supplied to the upstream cleaning tank 15' via the supply nozzle 14'. At this time, all of the effluent can be reused, or only a portion can be reused. In the case of only reusing a portion, an adjustment valve can be provided on the upstream side of the removal device 202, as shown in FIG4, to adjust the amount of effluent reused. At this time, in order to keep the cleaning liquid volume of the cleaning tank 15' constant, fresh cleaning liquid can be supplied to the cleaning tank 15' using other supply components, or the discharge rate of the discharge pump 12' can be adjusted. In this embodiment, the film of the coated membrane 1 is peeled off in two stages by the peeling mechanism 19 and the peeling mechanism 19', thus reducing the amount of peeling per step. In this way, the amount of film generated in the suction box 18 and suction box 18' can be reduced, further suppressing the re-attachment of the peeled film to the substrate film 2, or the increase in the concentration of film components in the cleaning solution in the downstream cleaning tank 15, thereby maintaining a high film peeling effect.

[0042] Furthermore, the peeling mechanism 19 and peeling mechanism 19', and the suction box 18 and suction box 18' need not be identical. For example, either suction box 18 or suction box 18' can have the structure of the suction box shown in FIG. 6. Apart from the above, it is the same as the film peeling device 101 in FIG. 1 and the film peeling device 201 in FIG. 4; therefore, descriptions of common components are omitted. [Example]

[0043] Hereinafter, embodiments are listed to illustrate the present invention, but the present invention is not necessarily limited thereto.

[0044] <Film with Coating> A film of polyvinyl alcohol resin with a thickness of 0.1 μm is formed on a substrate film of polyethylene terephthalate with a thickness of 30 μm and a width of 300 mm as a layer containing a water-soluble resin. Then, a film of curable silicone resin with a thickness of 0.1 μm is formed on it as a layer containing a release agent, thereby producing a film with coating.

[0045] <Peeling Evaluation Method> Peeling was evaluated using a commercially available dyne pen (surface energy: 30, 70 mN / m) and measured using the following method. At room temperature (23°C), the dyne pen was used to draw on the sample surface. If this state was maintained for more than 4 seconds, it was determined that the surface energy of the sample surface was higher than the surface energy of the dyne pen. If the cured silicone resin of the release agent of the coated film remained on the surface, the surface energy was less than 30 mN / m, therefore any dyne pen would bounce off the reagent on the sample surface and could not maintain the drawing. On the other hand, when the cured silicone resin coating of the release agent was peeled off, exposing the polyvinyl alcohol resin, the surface energy was 70 mN / m or higher, therefore any dyne pen could maintain the drawing. When both the release agent (cured silicone resin) and the water-soluble polyvinyl alcohol resin coating are peeled off, exposing polyethylene terephthalate (PET), the surface energy is 43.8 mN / m. Therefore, it can maintain a dyne pen drawing at 30 mN / m, but cannot maintain a dyne pen drawing at 70 mN / m. The above evaluation method is used to determine whether the coating of the coated film can be peeled off.

[0046] <Evaluation Method for Foreign Matter Re-attachment to the Membrane> The behavior of the peeled-off film is visually observed to confirm whether the peeled-off film re-attaches to the substrate film. In addition, the number of peeled-off films re-attached to the substrate film and carried into the winding section is counted using a linear camera installed in front of the winding section. Based on the membrane conveying speed and travel time, the number of peeled-off films carried into the recycling membrane per 100 m of membrane travel is calculated to determine whether the contamination into the recycling membrane caused by the re-attachment of the peeled-off film can be suppressed.

[0047] <Seal Peeling of Film with Self-Installed Coating> [Example 1] Using the film peeling device 101 shown in FIG. 1, the film 1 with the coating is peeled off. The film 1 with the coating is placed in the winding device 4 of the film peeling device 101 and transported to the cleaning tank 15 at a conveying speed of 50 m / min by the drive device 9, and comes into contact with warm water (40°C) as the cleaning liquid 16. Then, it comes into contact with the resin-made plastic scraper (manufactured by Fuji Shokō Co., Ltd., Hi-POM series, thickness 1.25 mm) as the peeling mechanism 19, and the film is peeled off. The substrate film 2 after the film has been peeled off is wound up by the winding device 5. At this time, the amount of cleaning liquid in the cleaning tank is set such that the time for the film 1 with the coating to come into contact with the cleaning liquid 16 before reaching the peeling mechanism 19 is 2 seconds. The suction box 18 is made of polytetrafluoroethylene, and as shown in FIG. 5, the two ends in the film width direction are in contact with the support roller 17. The inlet opening 20 and outlet opening 21 are both quadrilateral in shape, with a length of 320 mm in the membrane width direction and a length of 5 mm in the membrane thickness direction. The supply rate of cleaning fluid 16 delivered by the liquid delivery device 13 and the discharge rate of cleaning fluid 16a discharged by the discharge pump 12 are both set to 0.18 m³ / min. At this time, the calculated flow rate of cleaning fluid 16 at the outlet opening 21 is 56 m / min. After continuously peeling the film off the substrate membrane for 10 minutes using this device, the results show that the film of the curing silicone resin and the water-soluble polyvinyl alcohol resin of the release agent can be peeled off in both cases. In addition, the number of films reattached to the substrate membrane is two.

[0048] [Example 2] As shown in FIG. 4, a portion of the effluent discharged from the self-discharge pump 12 is filtered by the removal device 202 and then supplied to the cleaning tank 15 for reuse. Otherwise, the membrane is peeled off using the same device as in Example 1. As the removal device 202 for removing the membrane, a continuous centrifuge (manufactured by GEA Corporation, Japan, SSE20) is used. In addition, the adjusting valve 203 is adjusted to reuse 30% of the effluent and discard the remaining 70%, and the self-feeding device 13 delivers the same amount of fresh cleaning liquid as the discarded effluent. Under the same conditions as in Example 1, the membrane is continuously peeled off for 10 minutes, and the substrate membrane is checked. The results show that the membranes of the release agent, the cured silicone resin and the water-soluble polyvinyl alcohol resin, are peeled off in both cases. In addition, the number of membranes reattached to the substrate membrane is two.

[0049] [Example 3] The film-coated membrane 1 was peeled off using the film peeling device 301 shown in FIG. 5. The winding device 4, winding device 5, conveying device 9, conveying device 9', cleaning tank 15, cleaning tank 15', peeling mechanism 19, peeling mechanism 19', support roller 17, support roller 17', suction box 18, suction box 18', discharge pump 12, discharge pump 12', liquid delivery device 13, supply nozzle 14, and supply nozzle 14' of the film peeling device 301 are the same devices as in Example 1. In addition, the removal device 202 is the same continuous centrifuge as in Example 2. The amount of cleaning liquid in the cleaning tank was set such that the time for the film-coated membrane 1, which was conveyed to the cleaning tank 15 and the cleaning tank 15', to contact the cleaning liquid 16 and the cleaning liquid 16' before reaching the peeling mechanism 19 and the peeling mechanism 19' was 1 second, and the film was peeled off under the same conditions as in Example 1. At this time, the calculated flow rate of the cleaning fluid at outlet opening 21 and outlet opening 21' is 56 m / min. After continuously peeling the film off using this device for 10 minutes, the substrate film was checked, and the results showed that the film of the curing silicone resin and the water-soluble polyvinyl alcohol resin, which are the release agents, could be peeled off in both cases. In addition, the number of films reattached to the substrate film was zero.

[0050] [Example 4] The conveying speed was set to 70 m / min, and the thickness length of the inlet opening 20 and outlet opening 21 in the film thickness direction was set to 3.6 mm. The time for the film 1 with the film coating, which was conveyed to the cleaning tank 15, to contact the cleaning liquid 16 before reaching the peeling mechanism 19 was 1.4 seconds. Otherwise, the film was peeled off in the same manner as in Example 1. At this time, the calculated flow rate of the cleaning liquid at the outlet opening 21 was 78 m / min. After continuously peeling the film for 10 minutes using this device, the substrate film was checked. It was found that the curing silicone resin of the release agent could be peeled off, but the film of the water-soluble polyvinyl alcohol resin remained. In addition, the number of films reattached to the substrate film was eight.

[0051] [Example 5] The conveying speed was set to 70 m / min, and the thickness direction length of the inlet opening 20, inlet opening 20', outlet opening 21, and outlet opening 21' was set to 3.6 mm. The time for the membrane 1 with the coating, which was conveyed to the cleaning tank 15, to contact the cleaning liquid 16 before reaching the peeling mechanism 19 was 1.4 seconds. Otherwise, the coating was peeled off in the same manner as in Example 3. At this time, the calculated flow rate of the cleaning liquid at the outlet opening 21 and outlet opening 21' was 78 m / min. After continuously peeling the coating off for 10 minutes using this device, the substrate membrane was checked, and the results showed that the coatings of the release agent, the cured silicone resin and the water-soluble polyvinyl alcohol resin, were peeled off in all cases. In addition, the number of coatings reattached to the substrate membrane was zero.

[0052] [Example 6] The thickness length of the inlet opening 20 and the outlet opening 21 was set to 7 mm. Otherwise, the film was peeled off in the same manner as in Example 1. At this time, the calculated flow rate of the cleaning fluid at the outlet opening 21 was 40 m / min. After continuously peeling the film off for 10 minutes using this device, the substrate film was checked. It was found that the curable silicone resin of the release agent could be peeled off, but the film of water-soluble polyvinyl alcohol resin remained. In addition, the number of films reattached on the substrate film was seven.

[0053] [Example 7] The thickness length of the inlet opening 20 and the outlet opening 21 was set to 3.6 mm. Otherwise, the film was peeled off in the same manner as in Example 1. At this time, the calculated flow rate of the cleaning fluid at the outlet opening 21 was 78 m / min. After continuously peeling the film off for 10 minutes using this device, the substrate film was checked, and the results showed that the film of the curing silicone resin and the water-soluble polyvinyl alcohol resin of the release agent could be peeled off in both cases. In addition, the number of films reattached to the substrate film was zero.

[0054] [Comparative Example 1] Without a suction box 18, the cleaning liquid and the peeled film in the cleaning tank 15 were discharged from the bottom of the cleaning tank 15 using a discharge pump 12. Otherwise, the film was peeled off in the same manner as in Example 1. Using this device, the film was peeled off, and as a result, the film was suspended in the cleaning tank from the initial stage of peeling. In this state, after continuously peeling the film for 5 minutes, the substrate film was checked. It was found that the curing silicone resin of the release agent could be peeled off, but the film of water-soluble polyvinyl alcohol resin remained. In addition, the number of films reattached to the substrate film was 40. If the film was continuously peeled off for another 5 minutes (i.e., if the film was continuously peeled off for 10 minutes after the start of peeling), the number of films suspended in the cleaning tank increased, and the number of films reattached to the substrate film was 300. In addition, both polyvinyl alcohol resin and curing silicone resin remained on the substrate film.

[0055] The coating peeling results of the coated films in the embodiments and comparative examples are summarized in Table 1. In the table, whether the coating can be peeled off means that both the polyvinyl alcohol resin and the cured silicone resin, which serve as the coating on the substrate film, are peeled off from the substrate film, and the coated film is separated into the coating film and the substrate film. In addition, "partial coating remaining" means that in the coating on the substrate film, only the cured silicone resin on the surface is peeled off, and the polyvinyl alcohol resin remains on the substrate film and has not separated from the substrate film. Moreover, "coating remaining" means that both the polyvinyl alcohol resin and the cured silicone resin, which serve as the coating on the substrate film, remain on the substrate film, and the coating film has not separated from the substrate film.

[0056] [Table 1] (Table 1) Conveying speed [m / minute] At the exit opening flow rate [m / minute] Can the film be peeled off? ○: Film peeling ∆: Part of the membrane remains ×: Residual membrane The peeled film Number of reattached items [pieces / 100 m] Example 1 50 56 ○ 2 Example 2 50 56 ○ 2 Example 3 50 56 ○ 0 Example 4 70 78 ∆ 8 Example 5 70 78 ○ 0 Example 6 50 40 ∆ 7 Example 7 50 78 ○ 0 Comparative Example 1 50 - After 5 minutes: ∆ After 10 minutes: × After 5 minutes: 40 After 10 minutes: 300

[0057] [Comparison of Examples 1-3 with Comparative Example 1] It can be confirmed that Examples 1-3 of the present invention are superior to Comparative Example 1, which is the prior art, in terms of the ability of the film to be peeled off and the number of films reattached. No decrease in the peeling performance of the film or an increase in the number of films reattached to the substrate film was observed as the peeling treatment time passed. This confirms that in order to suppress the reattachment of the peeled film or the dissolution of at least a portion of the film components into the cleaning solution, which would reduce the peeling ability, it is important to set up a suction box as in Examples 1-3 to suction and discharge the film or cleaning solution inside.

[0058] [Comparison of Examples 1 and 2] Compared with Example 1, Example 2 achieved equivalent performance in terms of whether the film could be peeled off and the number of films reattached, while suppressing the amount of fresh cleaning solution used. This demonstrates that by using a removal device to filter the effluent discharged from the self-draining pump and supplying it to the cleaning tank, the aforementioned performance can be maintained while suppressing the costs associated with the cleaning solution.

[0059] [Comparison of Examples 1, 3, 4, and 5] Compared to Example 1, which has one cleaning tank, Example 3, which uses two cleaning tanks, shows a visually confirmed reduction in the amount of film suspended in the cleaning tank, and also a smaller number of film re-attaches. Furthermore, in Examples 4 and 5, where the conveying speeds of both are increased, it is confirmed that Example 5, with two cleaning tanks, not only exhibits superior film re-attachment compared to Example 4, which has one cleaning tank, but also demonstrates superior performance in evaluating film peelability. This confirms that by using multiple cleaning tanks for peeling, the re-attachment of the peeled film to the substrate film can be suppressed, or the concentration of film components in the downstream cleaning tank can be prevented from increasing, thus reducing peeling ability.

[0060] [Comparison of Examples 1, 6, and 7] It can be confirmed that, compared to Example 6, where the flow rate at the outlet opening is lower than the conveying speed, Example 1, where the conveying speed is higher, is superior in terms of the ability to peel off the film and the number of films reattached. Furthermore, in Example 7, where the flow rate at the outlet opening is even higher, exceeding 1.5 times the conveying speed, the number of films reattached is even lower. This demonstrates that increasing the flow rate at the outlet opening is crucial to suppress the reattachment of peeled films or the film dissolving into the cleaning solution and thus reducing peeling ability. [Industrial Applicability]

[0061] The present invention can be applied to a coating peeling device and a coating peeling method for coating films formed on a substrate film such as a resin film, paper film, or metal film, but is not limited to these uses. [Simplified Explanation of the Diagram]

[0015] FIG1 is a schematic diagram of the film peeling device 101 according to the first embodiment of the present invention. FIG2 is an enlarged view of the periphery of the suction box of the film peeling device of FIG1. ​​FIG3 is a directional view of FIG2 viewed from the X direction. FIG4 is a schematic diagram of the film peeling device 201 according to the second embodiment of the present invention. FIG5 is a schematic diagram of the film peeling device 301 according to the third embodiment of the present invention. FIG6 is a schematic diagram of the film peeling device 401 according to another embodiment of the present invention.

Claims

1. A film peeling device for peeling a film from a film having a film on at least one side of a substrate film, the film peeling device comprising: two or more cleaning tanks arranged along a conveying direction of the film; a supply device for supplying cleaning liquid to at least the cleaning tank disposed downstream in the conveying direction; a conveying device for conveying the film in a length direction such that the film sequentially passes through each of the cleaning tanks; a suction box disposed in each of the cleaning tanks, surrounding a portion of the conveying path of the film; a peeling mechanism, at least its front end in contact with the film, disposed in each suction box for peeling the film from the film; and a discharge device for discharging the cleaning liquid and the peeled film from each suction box out of the cleaning tanks. At least one of the discharge devices has a removal device for removing foreign matter from the discharge liquid, and supplies the discharge liquid with foreign matter removed to another cleaning tank located upstream of the cleaning tank including the discharge device in the conveying direction.

2. A film peeling apparatus for peeling a film from a substrate film having a film on at least one side, the film peeling apparatus comprising: a cleaning tank; a supply device for supplying cleaning liquid to the cleaning tank; a conveying device for conveying the film with the film on it in a longitudinal direction such that the film with the film on it passes through the cleaning tank; a suction box disposed in the cleaning tank and surrounding a portion of the conveying path of the film with the film on it by means of a gap allowing the film to pass through; a peeling mechanism having at least a front end in contact with the film with the film on it disposed in the suction box for peeling the film from the film with the film on it; and a discharge device for discharging the cleaning liquid and the peeled film from the suction box out of the cleaning tank.

3. The film peeling device as claimed in claim 2, wherein, The discharge device has a removal device for removing foreign matter from the discharge liquid, and supplies the discharge liquid with foreign matter removed to the cleaning tank.

4. A coating peeling method, wherein a coating is peeled off from a film having a coating on at least one side of a substrate film, wherein two or more cleaning tanks are arranged along the conveying direction of the film, cleaning fluid is supplied to at least the cleaning tank located downstream in the conveying direction, the film with the coating is conveyed along its length direction, passing sequentially through the cleaning fluid in each of the cleaning tanks, the film with the coating is introduced into a suction box having a gap for the film to pass through, which is disposed in the cleaning fluid in each of the cleaning tanks, the coating is peeled off in the suction box by a coating peeling mechanism, the cleaning fluid and the peeled coating in each suction box are discharged out of the cleaning tank, and after foreign matter is removed from the discharge fluid discharged from at least one of the suction boxes, the discharge fluid with the foreign matter removed is supplied to another cleaning tank located upstream in the conveying direction than the cleaning tank including the suction box.

5. A film peeling method, wherein a film-coated membrane having a film on at least one side of a substrate membrane is peeled off, wherein a cleaning liquid is supplied to a cleaning tank, the film-coated membrane is conveyed along its length through the cleaning liquid, the film-coated membrane is introduced into a suction box disposed in the cleaning liquid and having a gap for the membrane to pass through, the film is peeled off in the suction box by a film peeling mechanism, and the cleaning liquid and the peeled film in the suction box are discharged out of the cleaning tank.

6. The film peeling method as described in claim 5, wherein, After the foreign matter is removed from the effluent discharged from the suction box, the effluent with the foreign matter removed is supplied to the cleaning tank.

7. The film peeling method as described in any one of claims 4 to 6, wherein, The discharge volume of the discharge liquid from the suction box is set such that the flow rate of the cleaning liquid at the gap where the membrane with the coating leaves the suction box is greater than the transport speed of the membrane with the coating.

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