How to recycle release sheets

Abstract

To realize a method of recycling release sheets for effectively recycling the release sheets.SOLUTION: A method of recycling release sheets comprises the steps of: storing a supply amount of resin sheet laminates to a user company in a supply amount storage unit; recovering used release sheets from the user company using exclusive containers; measuring a weight of the recovered exclusive container to calculate a recovered amount; calculating a recovering amount predictive value of the release sheets in a calculation unit; comparing the recovered amount to the recovering amount predictive value in an evaluation unit, and when a difference between the recovered amount and the recovering amount predictive value exceeds a prescribed range, choosing an exclusive container as a target of sorted inspection of contents; inspecting the contents of the exclusive container of the sorted inspection target to sort the used release sheets; and reproducing the recovered used release sheets into a resin raw material.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present disclosure relates to a method for recycling release sheets. [Background technology]

[0002] In recent years, with growing awareness of environmental protection, it has been proposed to collect, reuse, or recycle a variety of products, from industrial products to everyday items, after use. The collection and recycling of resin products has attracted particular attention since the Plastic Resource Recycling Promotion Act was enacted. For example, the reuse of resin substrates used in the manufacturing process of laminates, including polarizing plates, has been considered (see, for example, Patent Document 1).

[0003] In recycling, it is important to efficiently collect and separate materials. The creation of a recycling system for printing paper materials is also being considered (see, for example, Patent Document 2). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent Publication No. 2015-118388 [Patent Document 2] Patent Publication No. 2017-139008 Summary of the Invention [Problem to be solved by the invention]

[0005] The problem with recycling is the contamination of foreign matter. When used resin products are collected, they contain a variety of resin materials, making separation essential. Furthermore, even if they are separated into single resin materials, they cannot be collected as a uniform material because each product has undergone various processes.

[0006] If resin materials are recovered from a single product, fairly uniform materials can be recovered. However, since the amount recovered from a single product is limited, it is often difficult to recycle efficiently.

[0007] Currently, a wide variety of labels with adhesives are in use. These labels are provided with a release sheet to protect the adhesive layer, and the release sheet is discarded after the label is peeled off. Labels are made from a variety of materials and are printed in a variety of ways. However, one type of release sheet can be used for almost any label. Therefore, if release sheets could be standardized and recovered after peeling, they would become an ideal recycled material.

[0008] An object of the present disclosure is to realize a method for recycling release sheets that effectively recycles release sheets. [Means for solving the problem]

[0009] A first aspect of the release sheet recycling method of the present disclosure includes the steps of: storing in a supply amount memory unit the supply amount of a resin sheet laminate to be supplied to a user, the resin sheet laminate having an adhesive sheet with an adhesive layer and a release sheet bonded to the adhesive sheet; collecting used release sheets peeled from the resin sheet laminate from the user using a dedicated container; measuring the mass of the dedicated container collected from the user and calculating the amount of used release sheets in the dedicated container as the collection amount; calculating in a calculation unit a predicted collection amount of release sheets from the user based on the supply amount stored in the supply amount memory unit; comparing the collection amount with the predicted collection amount in an evaluation unit, and if the deviation from the predicted collection amount exceeds a predetermined range, subjecting the dedicated container to a separate inspection of its contents; inspecting the contents of the dedicated container that has been subject to separate inspection and separating the used release sheets; and recycling the collected used release sheets into resin raw material.

[0010] In a first aspect of the release sheet recycling method, used release sheets are collected from users using a dedicated container, and if the collected amount differs from the predicted amount, the collected items in the dedicated container are subjected to a separate inspection. This makes the separate inspection more efficient while preventing foreign matter from being mixed in, allowing for stable and efficient recycling.

[0011] In the first aspect of the method for recycling release sheets, the method may further include a step of using a system that comprehensively calculates the costs required for recycling, separately for cases where the deviation from the predicted recovery amount falls within a predetermined range and cases where it does not, calculating the recovery cost per unit weight and calculating the compensation to be paid to the user business.

[0012] A second aspect of the release sheet recycling method of the present disclosure includes the steps of supplying a resin sheet laminate to a user, the resin sheet laminate having an adhesive sheet with an adhesive layer and a release sheet that is bonded to the adhesive sheet and has detectable optical properties; collecting the used release sheets that have been peeled from the resin sheet laminate from the user using a dedicated container; optically inspecting the contents of the dedicated container to confirm that the contents are release sheets that have been peeled from the adhesive sheet supplied to the user; and regenerating the confirmed used release sheets into resin raw material.

[0013] The second aspect of the release sheet recycling method involves collecting used release sheets from users in a special container and optically inspecting them to confirm that they were supplied to the user. This clarifies the origin of the collected material, reduces the risk of contamination, and enables stable and efficient recycling. A third aspect of the release sheet recycling method of the present disclosure includes the steps of: supplying a resin sheet laminate to a user, the resin sheet laminate having an adhesive sheet with an adhesive layer and a release sheet bonded to the adhesive sheet and having detectable optical properties; collecting used release sheets peeled from the resin sheet laminate from the user using a dedicated container and accumulating them at a first location; calculating the amount of used release sheets accumulated at the first location by measuring the mass of the dedicated containers accumulated at the first location; storing the progress of the accumulation amount in an accumulation amount memory unit and performing inventory management for each dedicated container; instructing the transport of the used release sheet or a processed product thereof to a second location; transporting the used release sheet or a processed product thereof to the second location based on the transport instruction; and regenerating the used release sheet or a processed product thereof transported to the second location into resin raw material.

[0014] In the third aspect of the method for recycling release sheets, used release sheets are collected from users in dedicated containers, and inventory management is performed based on the mass of the dedicated containers. This makes it easy to plan recycling and achieves efficient recycling.

[0015] In a third aspect of the method for recycling release sheets, the method may further include a step of storing the supply amount of resin sheet laminates to the user in a supply amount storage unit, and a step of predicting the time when the accumulated amount will exceed a set value based on the supply amount stored in the supply amount storage unit and planning a transportation schedule to the second base. By using such a configuration, the collection and transportation of recovered materials can be performed efficiently.

[0016] In each aspect, the used release sheet is a roll of multiple resin sheets connected via a connecting tape, and the method may include a step of detecting the connecting tape by measuring the optical or physical properties of the recovered used release sheet and removing the detected connecting tape prior to the recycling step. By using such a configuration, it is possible to make it less likely that the connecting tape will get mixed in.

[0017] In each aspect, the resin sheet laminate may be processed into a label product by a user. Even when processed by a user, the resin sheet laminate can be efficiently recycled.

[0018] The recycled material determination device of the present disclosure includes a supply amount memory unit that stores the supply amount to a user business of an adhesive sheet having an adhesive layer and a release sheet laminated to the adhesive sheet; a measurement unit that measures the mass of the dedicated containers collected from the user business and calculates the collection amount of used release sheets collected from the user business; a calculation unit that calculates a predicted collection amount of release sheets from the user business based on the supply amount to the user business stored in the supply amount memory unit; and an evaluation unit that compares the collection amount with the predicted collection amount and determines that the dedicated container is a target for sorting inspection if the difference exceeds a predetermined range.

[0019] By using such a determination device, the release sheets can be recycled efficiently. [Effects of the Invention]

[0020] According to the release sheet recycling method of the present disclosure, the release sheet can be recycled effectively. [Brief explanation of the drawings]

[0021] [Figure 1] FIG. 2 is a cross-sectional view showing an example of a resin sheet laminate including a release sheet. [Figure 2] FIG. 1 is a flow diagram illustrating a recycling method according to an embodiment. [Figure 3] 1 is a block diagram showing a recycled material discrimination device according to an embodiment; DETAILED DESCRIPTION OF THE INVENTION

[0022] 1, release sheet 111 to be recycled is bonded to adhesive sheet 112 to form resin sheet laminate 110. Adhesive sheet 112 has base sheet 113 and adhesive layer 114.

[0023] The resin sheet laminate 110 can be manufactured by various known methods, and the manufactured resin sheet laminate 110 is sold to a user business or a processing business. The resin sheet laminate 110 sold to a user business is used by the user business, and the resin sheet laminate 110 sold to a processing business is processed by the processing business, such as printing, and sold to the user business, who then uses it.

[0024] The adhesive sheet 112 is peeled off from the release sheet 111 by the user and attached to an object to be attached. The adhesive sheet 112 is not particularly limited, and may be a label with printing or the like on its surface, a protective film, tape, or the like.

[0025] Various materials such as resin, paper, metal, and composites thereof can be used for the base sheet 113. Furthermore, the base sheet 113 is not limited to a single layer, and can also be a laminate in which multiple layers are stacked.

[0026] The adhesive layer 114 may be a urethane-based, acrylic-based, silicone-based, rubber-based adhesive, or a plant-derived adhesive. While FIG. 1 shows an example in which the adhesive layer 114 is formed on only one side of the base sheet 113, it may also be a double-sided adhesive tape in which the adhesive layer 114 is formed on both sides of the base sheet 113.

[0027] The release sheet 111 is a sheet of recyclable resin. Although not particularly limited, polyester resin, particularly polyethylene terephthalate resin, is preferred because it is easy to recycle and there is a high demand for recycled raw materials. A release agent layer may be formed between the release sheet 111 and the adhesive layer 114. The release agent may be silicone-based, fluorine-based, or the like. An antistatic agent layer may also be formed on the surface of the release sheet 111 opposite the adhesive layer 114. The antistatic agent may be an ionic compound, a polymer-based compound such as polythiophene, or the like.

[0028] The resin sheet laminate 110 can be efficiently recycled into resin raw material by the recycling method shown in FIG.

[0029] In step S1, the manufactured resin sheet laminate 110 is either sold to a user and supplied to the user, or sold to a processor, who processes the resin sheet laminate and then supplies it to the user. The processor may print on the surface of the adhesive sheet 112, or perform other processes such as punching or half-cutting, in which a blade is inserted from the base sheet side to cut out part of the release sheet 111. The user may also perform printing or other processing themselves. However, processing is performed in a state where the adhesive sheet 112 and the release sheet 111 are bonded together, and the resin sheet laminate in which the adhesive sheet 112 and the release sheet 111 are bonded together is supplied to the final user. At this time, data such as the amount of resin sheet laminate 110 or its processed product supplied to the final user is stored for each user.

[0030] In step S2, the user who has been supplied with resin sheet laminate 110 or a processed product thereof uses it by peeling adhesive sheet 112 from release sheet 111. The user stores and accumulates used release sheets 111 after peeling, rather than discarding them.

[0031] In step S3, the used release sheets that have reached a predetermined amount are collected in a dedicated container. The dedicated container can be, for example, a container of a certain size and mass. It can also be a container to which a container number or the like is assigned and to which the container mass is linked. A specific example of a dedicated container is a flexible container box that combines a flexible container bag with a metal frame. By using a flexible container box, it is possible to efficiently collect used release sheets by utilizing a goods collection and delivery transport service for each unit container (such as JITBOX Charter Service (registered trademark)).

[0032] The dedicated container can be used not only for transporting used release sheets, but also for storing and collecting used release sheets by the user. In this case, the dedicated container can be provided with an indicator or the like to indicate when the amount of used release sheets in the dedicated container has reached a predetermined amount. In addition, a sensor or the like can be provided to detect when the amount of used release sheets in the dedicated container has reached a predetermined amount.

[0033] In step S4, the dedicated containers collected by the delivery system from the user businesses are accumulated at a designated location. The accumulated dedicated containers are weighed, and the amount of waste collected in the dedicated container is stored and tallied for each user business. The collected amount can be calculated by the difference between the mass of the dedicated container and the mass of an empty dedicated container. The mass of an empty dedicated container can be a predetermined value, or a value stored in association with the container number of the dedicated container, etc.

[0034] In step S5, the predicted amount of used release sheets to be collected from the user is calculated based on the stored amount of supplied resin sheet laminate. The predicted amount of collection can be calculated, for example, by multiplying the mass of the supplied resin sheet laminate by the mass ratio of the release sheets per unit mass of the resin sheet laminate. When the resin sheet laminate is sold, the sales area (m 2) and calculate the predicted collection amount by multiplying the sales area by the mass per unit area of ​​the release sheet. To improve accuracy, the predicted collection amount can also be calculated by taking into account various parameters such as past collection amounts. Note that the calculation of the predicted collection amount can be performed after the dedicated containers are collected, from the perspective of taking into account various parameters that fluctuate until the collection of the dedicated containers is completed, but considering the calculation method, it can be performed at any time between the determination of the supply amount and step S6 described below.

[0035] In step S6, the collected amount for each user is compared with the predicted collection amount to determine whether the corresponding dedicated container is subject to inspection. If the used release sheets are properly collected from the user, the collected amount should roughly match the predicted collection amount. If the collected amount is significantly lower than the predicted collection amount, it is suspected that the user has not sufficiently collected used release sheets, or that items other than used release sheets have been placed in the dedicated container. If the collected amount is significantly higher than the predicted collection amount, it is suspected that items other than used release sheets have been placed in the dedicated container. If there is a significant discrepancy between the collected amount and the predicted collection amount, it is highly likely that the used release sheets have not been properly collected, and the contents of the corresponding dedicated container are inspected. On the other hand, if the collected amount matches the predicted collection amount, it is possible to not inspect the contents of the corresponding dedicated container, or to perform only a simple inspection.

[0036] Whether the recovered amount and the predicted recovered amount match can be determined by whether the difference between them is within a predetermined range. The predetermined range can be set uniformly to a value of about 10% to 30%, or can be set based on the results of statistical analysis.

[0037] In step S7, the contents of the designated container are inspected. While various methods can be used to inspect the contents, optical inspection is preferred because it is easy. For example, optical properties attributable to the material of the release sheet can be inspected by irradiating the sheet with light and measuring the properties of the reflected light. Light properties can include various optical properties such as color, whiteness, reflectance, and the reflection intensity of light at specific wavelengths. Optical properties can also be measured using transmitted light. Furthermore, in addition to optical properties attributable to the material of the release sheet, methods can also be used in which specific optically identifiable symbols, characters, or colors are printed on the release sheet and then optically read. Optically readable barcodes, etc., can also be used. In the case of release sheets containing inorganic fillers such as silica particles, reflected light at specific wavelengths attributable to the inorganic filler can also be measured. Optical inspection can also be performed visually rather than using a camera or detection device. In this step, the properties measured can also be physical properties such as the thickness of the release sheet. Both optical and physical properties can also be measured.

[0038] By storing the optical characteristics of the release sheet at the time of shipment and comparing them with the inspection results after collection, it is possible to confirm that the release sheet is the one that was peeled off from the resin sheet laminate supplied to the user. When it is confirmed by the optical characteristics that the collected item is the release sheet that was supplied to the user, it is also possible not to compare the collected amount with the predicted value.

[0039] If the recovered material is confirmed to be a used release sheet by comparing the recovered amount with the predicted recovered amount and inspecting its optical properties, it is recycled into resin raw material in step S8. If a release agent layer or antistatic agent layer is present, it is removed. The release agent layer and antistatic agent layer can be removed by known chemical or physical methods. The method for recycling into resin raw material is not particularly limited, and various methods can be used depending on the resin composition of the release sheet. For example, the release sheet can be melted and recycled into pellets, or it can be decomposed into low-molecular-weight compounds by thermal or chemical decomposition and then recycled into a resin material. The recycled resin raw material can be used again to produce release sheets. When producing release sheets, recycled raw materials can be used alone, or they can be mixed with unused raw materials.

[0040] Resin sheet laminates are sometimes supplied to users in a rolled state. The adhesive sheet of the rolled resin sheet laminate can be attached to an adherend by an attachment device having a mechanism for feeding and winding the resin sheet laminate. In this case, the used release sheet from which the adhesive sheet has been peeled is wound up by a winding mechanism and collected in roll form. Used release sheets collected in roll form are not bulky and are advantageous for storage and transportation.

[0041] In the case of used release sheets wound into a roll, it is possible to easily determine whether the sheet was recovered from a resin sheet laminate supplied to a user by inspecting only the end of the roll without inspecting the entire sheet. This greatly simplifies the inspection process and improves recycling efficiency. Furthermore, by displaying information printed or otherwise near the end of the recovered roll, confirmation can be performed while the roll is still wound. Inspection can be greatly simplified by displaying the displayed information as an optically readable barcode or the like so that it can be compared with supply information for the user stored on a server or the like. Information can be printed only near the end of the roll, but it can also be printed at regular intervals across the entire release sheet so that the information is displayed near the end of the roll.

[0042] On the other hand, a roll-shaped resin sheet laminate may have a configuration in which multiple release sheets are connected by a connection tape. The connection tape, which is made of a material different from that of the release sheet, needs to be removed when recycling the used release sheet. The connection tape can be made detectable when inspecting the optical properties of the used release sheet. This makes it easy to remove the connection tape. Furthermore, instead of or in addition to inspecting the optical properties, the physical properties of the release sheet, such as thickness, may be inspected. The connection tape can also be automatically removed by linking an optical property or physical property inspection device with a connection tape removal device.

[0043] Whether the collected amount and the predicted collected amount match can also be determined automatically by recycled material determination device 200. As shown in Fig. 3, recycled material determination device 200 has a supply amount memory unit 211 that stores the supply amount to the user business, a measurement unit 212 that calculates the amount of material in the collected dedicated container, a calculation unit 213 that calculates the predicted collection amount of used release sheets from the user business based on the supply amount stored in supply amount memory unit 211, and an evaluation unit 214 that compares the collected amount with the predicted collection amount, and determines that the dedicated container is a target for separate inspection if the difference exceeds a predetermined range.

[0044] The supply amount storage unit 211 can be configured to directly input the supply amount, or can be configured to read out business information, etc., stored on a server. The measurement unit 212 can be configured to be integrated with a measurement unit that measures the mass of the dedicated container and automatically acquire the mass of the dedicated container to calculate the recovery amount, or can be configured to measure the mass of the dedicated container using an independent device. The evaluation unit 214 may have a function to output a label, etc. to be affixed to the corresponding dedicated container based on the evaluation result. The calculation unit 213 that calculates the predicted recovery amount can be configured to double as the evaluation unit. Alternatively, the evaluation unit can be configured to perform the function of calculating the recovery amount from the mass of the dedicated container.

[0045] While the recycling method described above uses data on the collected amount to confirm that the collected materials are used release sheets, the data on the collected amount can also be used for other purposes. For example, when used release sheets are collected from a user and collected in a dedicated container at a first location, then transferred to a larger dedicated container and transported to a second location for recycling, the data on the collected amount can be used to manage the inventory of used release sheets collected at the first location. In this case, the data on the amount of resin sheet laminates supplied to the user can be used to predict when the accumulated amount of used release sheets at the first location will exceed a predetermined value, and a transport schedule for each dedicated container to the second location can be planned. Furthermore, transportation arrangements can be made with a delivery company based on this schedule. This allows for smooth transport between locations and minimizes the need for collection space, resulting in efficient recycling. When there are multiple first locations, centralized management of data from each first location allows for more efficient planning of transport and recycling facility operation.

[0046] At the first site, the used release sheets may be subjected to a predetermined pre-processing step to facilitate recycling at the second site. For example, the used release sheets may be cut or crushed, or melted and processed into pellets. This processed product may be transported to the second site. In this case, the inventory of the used release sheets may also be managed, and the transport schedule for the used release sheets, which is planned based on the predicted amount of accumulated used release sheets, may be modified according to the inventory of the processed products.

[0047] Data on the collected amount can also be used to calculate the compensation to be paid to user businesses. Paying compensation to user businesses allows for smoother collection. Furthermore, paying higher compensation to user businesses that collect used release film in a state that is easy to recycle raises user awareness and allows for the collection of used release film in better condition. For example, the compensation paid to user businesses can reflect the difference in recycling costs between when the collected amount matches the predicted collection amount and when it does not. In this case, it is preferable to comprehensively calculate recycling costs using a system that stores various parameters that affect recycling costs, such as the transportation costs of the release film and the prices of the chemicals used in recycling. This will increase user businesses' understanding and improve their awareness. It is also possible to calculate the compensation to be paid to user businesses by pre-storing information on the trading price of recycled resin raw materials in the supply amount storage unit 211, etc., and subtracting the recycling costs from the trading price of the resin raw materials.

[0048] The calculation of such compensation may be performed by the calculation unit 213 of the recycled material determination device. The recycled material determination device may also be configured to be linked to an optical inspection device.

[0049] The release film recycling method disclosed herein collects and recycles a single used product, release film, from users, allowing for the effective collection of homogeneous materials. Furthermore, by managing supply information and collection information for users, effective collection can be achieved. [Industrial Applicability]

[0050] The release sheet recycling method of the present disclosure can effectively recycle release sheets and is useful in the fields of the resin industry and the recycling industry. [Explanation of symbols]

[0051] 110 Resin sheet laminate 111 Peel-off sheet 112 adhesive sheet 113 Base sheet 114 Adhesive layer 200 Recycled material determination device 211 Supply amount storage unit 212 Measurement Department 213 Arithmetic section 214 Evaluation Department

Claims

1. a step of supplying a resin sheet laminate to a user, the resin sheet laminate including a pressure-sensitive adhesive sheet having a pressure-sensitive adhesive layer and a release sheet that is attached to the pressure-sensitive adhesive sheet and has detectable optical properties; a step of collecting used release sheets peeled off from the resin sheet laminate from the user using a dedicated container and accumulating the used release sheets at a first base; measuring the mass of the dedicated containers accumulated at the first location to calculate the amount of the used release sheets accumulated at the first location; storing the change in the accumulated amount in an accumulated amount storage unit and performing inventory management for each of the dedicated containers; instructing the transportation of the used release sheet or a processed product thereof to a second location; transporting the used release sheet or a processed product thereof to the second base based on the instruction to transport; and a step of regenerating the used release sheet or a processed product thereof transported to the second base into a resin raw material.

2. storing the supply amount of the resin sheet laminate to the user in a supply amount storage unit; The release sheet recycling method of claim 1, further comprising a step of predicting when the accumulated amount will exceed a set value based on the supply amount stored in the supply amount memory unit, and planning a transportation schedule to the second location.

3. 3. The method for recycling release sheets according to claim 1 or 2, wherein the used release sheets are wound into a roll by connecting multiple release sheets via connecting tape, and the method includes a step of detecting the connecting tape by measuring the optical or physical properties of the recovered used release sheets and removing the detected connecting tape prior to the regenerating step.

4. The method for recycling a release sheet according to any one of claims 1 to 3, wherein the resin sheet laminate is processed into a label product by the user.

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