How to recycle release sheets

Abstract

To provide a recycling method of a peelable sheet which effectively recycles a peelable sheet.SOLUTION: A recycling method of a peelable sheet includes the steps of: supplying a resin sheet laminate to a use company; recovering a used peelable sheet from the use company through a connection tape, using an exclusive vessel, in a state of being a connection sheet where a plurality of peelable sheets are connected to each other; confirming that a content is a used peelable sheet peeled from the resin sheet laminate supplied to the use company by optical inspection; measuring optical characteristics or physical characteristics of the connection sheet, thereby detecting the connection tape, and removing the detected connection tape; and recycling the used peelable sheet 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 Art

[0002] In recent years, with the increasing awareness of environmental protection, it has been proposed that various products ranging from industrial products to daily necessities should be collected for reuse or recycling after use. Regarding the collection and recycling of resin products, the Act on Promotion of Plastic Resource Circulation has been enacted, attracting particular attention. For example, reuse of resin base materials used in the manufacturing process of laminates including polarizing plates has been studied (see, for example, Patent Document 1).

[0003] In recycling, it is important to efficiently collect and sort materials. Construction of recycling systems for printing paper materials has also been studied (see, for example, Patent Document 2).

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Summary of the Invention

Problem to be Solved by the Invention

[0005] A problem in recycling is the contamination of foreign substances. When used resin products are collected, they contain miscellaneous resin materials, so sorting is essential. Further, even when sorted into only a single resin material, various processing have been performed for each product, so the material cannot be recovered as a uniform material.

[0006] Recovering resin material from a single product can yield a fairly uniform material. However, the amount recovered from a single product is limited, making efficient recycling difficult in many cases.

[0007] Currently, a large number of labels with adhesives are in use. These labels are equipped with a release liner to protect the adhesive layer, and the release liner is discarded after the label is removed. Labels are made from various materials and printed in various ways. On the other hand, a single type of release liner can be used for almost any label. Therefore, if the release liner could be standardized and collected after removal, it could become an ideal recycled material.

[0008] The objective of this disclosure is to realize a method for recycling release sheets that effectively recycles them. [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 storage unit the amount of a resin sheet laminate having an adhesive layer and a release sheet bonded to the adhesive layer to a user; collecting used release sheets peeled off 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 a predicted collection amount of release sheets from the user in a calculation unit based on the supply amount stored in the supply amount storage unit; comparing the collection amount and the predicted collection amount in an evaluation unit, and if the deviation from the predicted collection amount exceeds a predetermined range, making the dedicated container subject to content separation inspection; inspecting the contents of the dedicated container subject to separation inspection and separating the used release sheets; and recycling the collected used release sheets into resin raw materials.

[0010] The first aspect of the release sheet recycling method involves collecting used release sheets from users using a dedicated container, and if the collected amount deviates from the predicted collection amount, the collected items in the dedicated container are subject to sorting inspection. This makes sorting inspection more efficient and reduces the likelihood of foreign matter contamination, thus enabling stable and efficient recycling.

[0011] In the first embodiment 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, to calculate the recovery cost per unit weight, and to calculate the compensation to be paid to the user.

[0012] A second aspect of the method for recycling release sheets of the present disclosure comprises the steps of: supplying a resin sheet laminate having an adhesive sheet having an adhesive layer and a release sheet bonded to the adhesive sheet and having detectable optical properties to a user; collecting used release sheets peeled off from the resin sheet laminate from the user using a dedicated container; confirming that the contents of the dedicated container are release sheets peeled off from the adhesive sheet supplied to the user by optically inspecting the contents; and recycling the confirmed used release sheets into resin raw materials.

[0013] A second aspect of the release sheet recycling method involves collecting used release sheets from the user using a dedicated container and confirming that they were supplied to the user by optical inspection. This clarifies the origin of the collected materials, reduces the likelihood of foreign matter contamination, and enables stable and efficient recycling. A third aspect of the release sheet recycling method of the present disclosure comprises the steps of: supplying a resin sheet laminate having an adhesive sheet having an adhesive layer and a release sheet bonded to the adhesive sheet and having detectable optical properties to a user; collecting used release sheets peeled from the resin sheet laminate from the user using a dedicated container and accumulating them at a first base; calculating the amount of used release sheets accumulated at the first base by measuring the mass of the dedicated containers accumulated at the first base; storing the changes in the accumulated amount in an accumulation amount storage unit and performing inventory management for each dedicated container; instructing the transfer of used release sheets or processed products thereof to a second base; transferring used release sheets or processed products thereof to the second base based on the transfer instruction; and recycling the used release sheets or processed products thereof transferred to the second base into resin raw materials.

[0014] A third method for recycling release sheets involves collecting used release sheets from users using dedicated containers and managing inventory based on the weight of the containers. This allows for easy planning of recycling and enables efficient recycling.

[0015] In a third embodiment of the release sheet recycling method, the method may further include the steps of storing the amount of resin sheet laminates to be supplied to the user in a supply amount storage unit, and predicting when the accumulated amount will exceed a set value based on the supply amount stored in the supply amount storage unit, and formulating a transfer schedule to a second base. With such a configuration, the collection and transfer of the collected materials can be carried out efficiently.

[0016] In each embodiment, the used release sheet is wound into a roll with multiple resin sheets connected via connecting tape, and the process may include a step of detecting the connecting tape by measuring the optical or physical properties of the collected used release sheet and removing the detected connecting tape before the regeneration step. This configuration makes it less likely for the connecting tape to be mixed in.

[0017] In each embodiment, the resin sheet laminate may be processed as a label product by an end user. Efficient recycling can be achieved even when processed by an end user.

[0018] The recycled material determination device of the present disclosure includes: a supply amount storage unit that stores a supply amount of a pressure-sensitive adhesive sheet to an end user, wherein the pressure-sensitive adhesive sheet has a pressure-sensitive adhesive layer and a release sheet bonded to the pressure-sensitive adhesive layer; a measurement unit that measures a mass of a dedicated container collected from the end user to calculate a collected amount of used release sheets collected from the end user; a calculation unit that calculates a predicted collected amount of release sheets from the end user based on the supply amount to the end user stored in the supply amount storage unit; and an evaluation unit that compares the collected amount with the predicted collected amount, and determines that the dedicated container is a target for sorting inspection when a difference between the collected amount and the predicted collected amount exceeds a predetermined range.

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

Effect of the Invention

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

[0021] [Figure 1] It is a cross-sectional view showing an example of a resin sheet laminate including a release sheet. [Figure 2] It is a flow diagram showing a recycling method according to one embodiment. [Figure 3] It is a block diagram showing a recycled material determination device according to one embodiment. Mode for Carrying Out the Invention

[0022] As shown in Figure 1, the release sheet 111, which is to be recycled, is bonded with the adhesive sheet 112 to form a resin sheet laminate 110. The adhesive sheet 112 has a base sheet 113 and an 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 users or processors. The resin sheet laminate 110 sold to users is used by the users, and the resin sheet laminate 110 sold to processors is processed by the processors (such as printing) and sold to users, and used by the users.

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

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

[0026] The adhesive layer 114 can be an adhesive such as a urethane-based, acrylic-based, silicone-based, or rubber-based adhesive. It can also be a plant-derived adhesive. Figure 1 shows an example in which the adhesive layer 114 is formed on only one side of the base sheet 113, but it can 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. While not particularly limited, polyester resin, especially polyethylene terephthalate resin, is preferred because it is easily recyclable and there is a high demand for recycled materials. A release agent layer can also be formed between the release sheet 111 and the adhesive layer 114. The release agent can be silicone-based, fluorine-based, etc. An antistatic agent layer can also be formed on the side of the release sheet 111 opposite to the adhesive layer 114. The antistatic agent can be an ionic compound, a polymer compound such as polythiophene, etc.

[0028] The resin sheet laminate 110 can be efficiently recycled and regenerated into resin raw materials by the recycling method shown in Figure 2.

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

[0030] In step S2, the user who receives the resin sheet laminate 110 or its processed product peels the adhesive sheet 112 from the release sheet 111 and uses it. The user stores and accumulates the used release sheet 111 after peeling, without discarding it.

[0031] In step S3, used release sheets that have reached a predetermined quantity 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 with a container number, etc., linked to the container mass. A specific example of a dedicated container is a flexible container box that combines a flexible container bag and a metal frame. By using a flexible container box, it becomes possible to efficiently collect used release sheets by utilizing a goods collection and delivery service for each unit container (JITBOX Charter Service (registered trademark), etc.).

[0032] The dedicated container can be used not only for transporting used release sheets, but also for storing and accumulating used release sheets at the user's location. In this case, the dedicated container can be equipped with indicators to show when the amount of used release sheets inside has reached a predetermined amount. It can also be equipped with sensors to detect when the amount of used release sheets inside the dedicated container has reached a predetermined amount.

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

[0034] In step S5, the estimated amount of used release sheets recovered from the user is calculated based on the stored supply amount of resin sheet laminates. The estimated recovery amount can be calculated, for example, by multiplying the mass ratio of release sheets per unit mass of resin sheet laminates by the mass of the supplied resin sheet laminates. When selling resin sheet laminates, the sales area (m²) 2The sales area may be recorded, and the predicted recovery amount may be calculated by multiplying the sales area by the mass per unit area of ​​the release sheet. To improve accuracy, the predicted recovery amount can also be calculated by taking into account various parameters such as past recovery amount performance. The calculation of the predicted recovery amount can be performed after the dedicated containers have been collected, taking into account various parameters that will fluctuate until the collection of the dedicated containers is completed. However, considering the calculation method, it can be performed at any point between the time the supply amount is determined and step S6 shown below.

[0035] In step S6, the amount recovered by each user is compared with the predicted recovery amount to determine whether the relevant dedicated container is subject to inspection. If used release sheets are correctly recovered from the user, the recovered amount should be approximately equal to the predicted recovery amount. If the recovered amount is significantly lower than the predicted recovery amount, it is suspected that the user has not recovered enough used release sheets, or that something other than used release sheets has been placed in the dedicated container. Conversely, if the recovered amount is significantly higher than the predicted recovery amount, it is suspected that something other than used release sheets has also been placed in the dedicated container. If the recovered amount and the predicted recovery amount differ significantly, it is highly likely that the used release sheets have not been recovered correctly in any case, so the contents of the relevant dedicated container are inspected. On the other hand, if the recovered amount and the predicted recovery amount are equal, the contents of the relevant dedicated container may not be inspected, or only a simple inspection may be performed.

[0036] Whether the recovered amount matches the predicted recovered amount can be determined by checking if the difference between the two falls within a predetermined range. This predetermined range can be uniformly set to a value of approximately 10% to 30%, or it can be determined based on the results of statistical analysis.

[0037] In step S7, the contents of the special container to be inspected are examined. The contents can be inspected by various methods, but optical inspection is preferred because it is easy to perform. For example, by irradiating with light and measuring the characteristics of the reflected light, the optical properties caused by the material of the release sheet can be inspected. Various optical properties can be used as light properties, such as color, whiteness, reflectance, and the reflection intensity of light of a specific wavelength. Optical properties can also be measured using transmitted light. Furthermore, in addition to optical properties caused by the material of the release sheet, it is also possible to use a method in which specific symbols, letters, or colors that are optically identifiable are printed on the release sheet and read optically. Optically readable barcodes can also be used. In the case of a release sheet containing inorganic fillers such as silica particles, it is also possible to measure the reflected light of a specific wavelength caused by the inorganic fillers. Optical inspection can also be performed visually, without using a camera or detection device. Note that in this step, the characteristics to be measured can also be physical characteristics such as the thickness of the release sheet. It is also possible to measure both optical and physical characteristics.

[0038] By recording the optical properties of the release sheet at the time of shipment and comparing them with the inspection results after recovery, it is possible to confirm that the release sheet was peeled off from the resin sheet laminate supplied to the user. When confirming that the recovered material is a release sheet supplied to the user based on its optical properties, it is also possible to avoid comparing the recovered amount with a predicted value.

[0039] By comparing the recovered amount with the predicted recovered amount and inspecting its optical properties, recovered material confirmed to be used release sheets is recycled into resin raw material in step S8. If a release agent layer or antistatic agent layer is present, these are removed. The release agent layer and antistatic agent layer can be removed by known chemical or physical methods. The method of 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, it can be recycled into pellets by melting it as is, or it can be decomposed into low-molecular-weight compounds by thermal or chemical decomposition and then recycled into resin material. The recycled resin raw material can be used again in the production of release sheets. When producing release sheets, only recycled raw material can be used, but it can also be mixed with unused raw material.

[0040] The resin sheet laminate may be supplied to the user in a rolled state. The rolled resin sheet laminate can be used to attach the adhesive sheet to a substrate using an application device that has 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 off, is wound up into a roll by the winding mechanism and collected. Used release sheets collected in a roll are compact and advantageous for storage and transportation.

[0041] In the case of used release sheets wound into a roll, it is easy to determine whether they were recovered from a resin sheet laminate supplied to a user by inspecting only the end of the roll, without inspecting the entire roll. This significantly simplifies the inspection process and improves the efficiency of recycling. Furthermore, if information is printed on the part near the end of the recovered roll, verification can be performed while the roll is still wound. If the displayed information is an optically readable barcode or similar, and can be compared with the supply information to the user stored on a server, the inspection can be greatly simplified. The information can be printed only near the end when the roll is wound, but it can also be printed at regular intervals across the entire release sheet so that the information is displayed near the end when the roll is wound.

[0042] On the other hand, roll-shaped resin sheet laminates may have a configuration in which multiple release sheets are connected by connecting tape. Connecting tape made of a different material from the release sheet needs to be removed when recycling used release sheets. When inspecting the optical properties of used release sheets, it is possible to detect the connecting tape. This makes it easier to remove the connecting tape. In addition, physical properties of the release sheet, such as thickness, may be inspected instead of or in conjunction with the inspection of optical properties. Connecting tape can also be automatically removed by linking an optical or physical properties inspection device with a connecting tape removal device.

[0043] The determination of whether the recovered amount matches the predicted recovered amount can also be performed automatically by the recycled material determination device 200. As shown in Figure 3, the recycled material determination device 200 includes a supply amount storage unit 211 that stores the amount supplied to the user business, a measurement unit 212 that calculates the amount of recovered material in the collected dedicated container, a calculation unit 213 that calculates a predicted recovered amount of used release sheets from the user business based on the supply amount stored in the supply amount storage unit 211, and an evaluation unit 214 that compares the recovered amount with the predicted recovered amount and determines that if the difference exceeds a predetermined range, it is a dedicated container subject to sorting inspection.

[0044] The supply quantity storage unit 211 can be configured to receive the supply quantity directly, or it can be configured to read sales information, etc., from a server. The measurement unit 212 can be configured to automatically acquire the mass of the dedicated container and calculate the recovery amount in conjunction with a measurement unit that measures the mass of the dedicated container, but the mass measurement of the dedicated container can also be performed by an independent device. The evaluation unit 214 may have a function to output labels, etc., to be affixed to the relevant dedicated container based on the evaluation results. The calculation unit 213 that calculates the predicted recovery amount can be configured to be used in conjunction with the evaluation unit. Alternatively, the evaluation unit can be configured to handle the function of calculating the recovery amount from the mass of the dedicated container.

[0045] While we have described a recycling method that uses data on the amount of collected materials to confirm that the collected materials are used release sheets, this data can also be used for other purposes. For example, if dedicated containers collected from users are accumulated at a first location, then transferred to larger dedicated containers and moved to a second location for recycling, the data on the amount of collected materials can be used to manage the inventory of used release sheets accumulated at the first location. In this case, based on data on the amount of resin sheet laminates supplied to users, it is possible to predict when the amount of used release sheets accumulated at the first location will exceed a predetermined value, and a transfer schedule for each dedicated container to the second location can be planned. Furthermore, arrangements for transfer can be made with delivery companies based on this schedule. In this way, transfers between locations can be carried out smoothly, and the amount of space required for collection can be minimized, thus enabling efficient recycling. If there are multiple first locations, centralizing the management of data from each first location will allow for even more efficient planning of transfers and the operation of recycling facilities.

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

[0047] The data on the amount of recovered material can also be used to calculate the compensation to be paid to the user. Paying compensation to the user allows for smoother recovery. Furthermore, by paying a higher compensation to the user who recovers used release film in a condition that facilitates recycling, it is possible to raise the user's awareness and recover used release film in better condition. For example, the compensation paid to the user can reflect the difference in recycling costs that arises when the recovered amount matches the predicted amount and when they do not. In this case, it is preferable to comprehensively calculate the recycling costs using a system that stores various parameters that affect the costs required for recycling, such as the transportation costs of the release film and the price of the chemicals used for recycling. This will increase the user's satisfaction and lead to improved awareness. Alternatively, information on the transaction price of recycled resin raw materials may be stored in advance in the supply amount storage unit 211, etc., and the compensation to be paid to the user may be calculated by subtracting the above-mentioned recycling costs from the transaction price of the resin raw materials.

[0048] The calculation of such compensation can also be performed in the calculation unit 213 of the recycled material determination device. Furthermore, the recycled material determination device can be configured to work in conjunction with an optical inspection device.

[0049] The release film recycling method described herein effectively recovers homogeneous material by collecting and recycling a single used product, the release film, from the user. Furthermore, effective recovery can be achieved by managing supply information to the user and collection information. [Industrial applicability]

[0050] The release sheet recycling method described herein 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 Release sheet 112 Adhesive Sheets 113 Base sheet 114 Adhesive layer 200 Recycled Material Identification Device 211 Supply amount storage unit 212 Measurement Unit 213 Arithmetic section 214 Evaluation Department

Claims

1. The steps include supplying a resin sheet laminate to a user, which comprises an adhesive sheet having an adhesive layer and a release sheet made of resin that is bonded to the adhesive sheet and has detectable optical properties, The steps include: collecting the release sheets peeled off from the resin sheet laminate from the user in a connected sheet form, where multiple release sheets are connected via connecting tape, using a dedicated container; The steps include: optically inspecting the contents of the dedicated container to confirm that the contents are release sheets peeled off from the resin sheet laminate supplied to the user; The steps include detecting the connecting tape by measuring the optical or physical properties of the connecting sheet and removing the detected connecting tape, A method for recycling release sheets, comprising the step of regenerating the confirmed release sheet into a resin raw material.

2. The method for recycling a release sheet according to claim 1, wherein the release sheet is provided with an optically identifiable code, and when optically inspecting the contents of the dedicated container, the code provided on the release sheet is read.

3. A method for recycling a release sheet according to claim 1 or 2, further comprising the step of producing a new resin release sheet using the recycled resin raw material.

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