Method and apparatus for separating and recovering constituent materials of absorbent articles, and method for manufacturing recycled unused absorbent materials.

Abstract

To separate and recover constituent materials of unused absorbent articles while preserving their high quality.SOLUTION: A method for separating and recovering constituent materials of unused water-absorbing articles includes: a dissolution step (step S1) for immersing an unused absorbent article (target 110), where sheets 20 containing pulp fiber 11 and SAP 12 as absorbers 10 are bonded with an adhesive, in a solvent 120, to dissolve the adhesive in the solvent 120; a separation recovery step (step S2) for separating and recovering constituent materials of the absorbent article (target 110) from which the adhesive has been dissolved and removed, such as the sheets 20, the pulp fiber 11, and the SAP12; and a drying step (step S3) for drying the separated and recovered constituent materials such as the sheets 20, the pulp fiber 11, and the SAP12.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a method and apparatus for separating and recovering constituent materials of unused absorbent articles, such as out-of-specification products (defective products) and chips (cut ends) generated in the manufacturing process of absorbent articles such as paper diapers and sanitary napkins, and more particularly, to a method and apparatus for separating and recovering constituent materials of absorbent articles that can separate and recover the constituent materials of unused absorbent articles with high quality.

Background Art

[0002] In the manufacturing process of absorbent articles such as paper diapers, sanitary napkins, incontinence (urine collection) pads, pantiliners, and pet sheets, there may occur breakage, contamination, poor adhesion, folding, misalignment or loss of constituent materials, or seams, creases, wrinkles, etc. that are not assumed in the design on sheets or tapes. There may also be out-of-specification products (defective products) due to the pulp fiber content or the amount of superabsorbent polymer (SAP) not meeting the predetermined specifications. In particular, since such absorbent articles are used in delicate areas, they are strictly inspected to ensure safety and security, and it is widely practiced to prevent out-of-specification products (defective products) from entering the market. As a result, the amount of defective products generated in the manufacturing process cannot be ignored. In addition, in the manufacturing process of mass-producing absorbent articles, the outside of the absorbent body containing pulp fibers and superabsorbent polymer is covered with a plurality of layers of sheets of a predetermined size, then heat-sealed into smaller pieces of the product size, and trimmed and cut into individual products, resulting in chips (cut ends). Such out-of-specification products and chips may be crushed and discarded (incinerated or landfilled), but in recent years, from the perspective of environmental considerations such as resource conservation, energy conservation, and carbon dioxide emissions associated with the incineration of waste, and also because the production volume of absorbent articles such as paper diapers is expected to increase with the progress of an aging society, it is desired to recover and recycle the constituent materials of out-of-specification products and chips generated in the manufacture of absorbent articles.

[0003] Therefore, for example, Patent Documents 1 to 4 propose that off-spec products and the like generated during the manufacturing of absorbent articles be crushed to separate and recover their constituent materials for recycling. [Prior art documents] [Patent Documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2001-336077 [Patent Document 2] International Publication No. 2017 / 104062 [Patent Document 3] Japanese Patent Publication No. 2007-175591 [Patent Document 4] Japanese Patent Publication No. 2022-15986 [Overview of the project] [Problems that the invention aims to solve]

[0005] However, in the prior art described in Patent Documents 1 to 4, the absorbent articles are dismantled by applying physical impact or mechanical cutting force, such as crushing or cutting, to extract the pulp fibers and granular superabsorbent polymer (SAP) embedded between the front and back sheets. When crushing or cutting is performed, the crushed pieces (cut pieces, shredded pieces) become hard because adhesive (hot melt adhesive) is used to bond the constituent materials of the absorbent articles together, and the cut pieces of sheets, etc., become entangled with the pulp fibers, making it difficult to separate the constituent materials. This results in a time-consuming and energy-intensive process for separating and recovering the constituent materials, and a low recovery rate. Furthermore, even if the constituent materials can be recovered, the adhesive (hot melt adhesive) remains attached, making it difficult to recycle them as material resources. In particular, attempting to break down and defibrate the solidified parts of the materials in order to increase the recovery rate requires a large amount of energy. Furthermore, this large amount of energy causes the granular superabsorbent polymer to become finer and pulverized, altering its original properties and making it unsuitable for recycling as an absorbent material in absorbent articles. Specifically, when superabsorbent polymer is finely granulated or pulverized, its water absorption properties decrease, and the particle size becomes too small, making it more likely to appear on the outside of the product when recycled as an absorbent material in absorbent articles, thus degrading the product's quality and making recycling as an absorbent material in absorbent articles difficult. In addition, if fine particles of superabsorbent polymer are released into wastewater, it also creates a problem of the burden on wastewater treatment.

[0006] Therefore, the present invention aims to provide a method and apparatus for separating and recovering the constituent materials of absorbent articles, which can separate and recover unused absorbent articles with high quality, as well as a method for manufacturing recycled unused absorbent materials. [Means for solving the problem]

[0007] The method for separating and recovering the constituent materials of an absorbent article according to claim 1 involves, in a solvent treatment step, immersing an unused absorbent article, which is formed by surrounding an absorbent with a sheet and joining the sheets with an adhesive, in a solvent to dissolve the adhesive in the solvent; in a separation and recovery step, separating and recovering the constituent materials of the absorbent article that have been dissociated by the dissolution of the adhesive in the solvent; and in a drying step, drying the separated and recovered constituent materials.

[0008] The above solvent treatment process involves immersing an absorbent article, which is formed by surrounding an absorbent material containing pulp fibers and a superabsorbent polymer with a sheet and joining the sheets with an adhesive, in a solvent to dissolve and remove the adhesive from the absorbent article using the solvent.

[0009] Here, the absorbent article is, for example, an article used to absorb liquids discharged from a person or animal, such as a disposable diaper, sanitary napkin, incontinence pad, panty liner, or pet sheet, and is formed by, for example, enclosing an absorbent body containing pulp fibers and a superabsorbent polymer with a sheet and joining the opposing sheets together with a hot melt adhesive. Furthermore, the unused absorbent materials mentioned above refer to loss items such as off-spec products (defective products) and trimmed scraps (cut edges) that are generated during the manufacturing process of absorbent materials such as disposable diapers. Furthermore, the above-mentioned solvent can be any solvent capable of dissolving the hot-melt adhesive used in absorbent articles. Preferably, a halogenated hydrocarbon solvent such as a petroleum-based solvent containing paraffin, naphthene, etc., or a chlorine-based solvent such as tetrachloroethylene or trichloroethylene is used.

[0010] The above separation and recovery process is a process for separating and recovering the constituent materials such as absorbent sheets and absorbent bodies containing pulp fibers and superabsorbent polymers that have been dissociated by dissolving and removing the adhesive. For example, the constituent materials are separated by utilizing differences in dimensions, specific gravity, etc. The above drying process involves drying the separated constituent materials to volatilize and remove the solvent adhering to them.

[0011] Claim 1 The solvent used to dissolve the adhesive of the absorbent article in the method for separating and recovering the constituent materials of the absorbent article of the invention is preferably a petroleum-based and / or halogenated hydrocarbon-based dry cleaning solvent. As the above-mentioned petroleum-based solvent, petroleum-based solvents containing paraffin, naphthenes, etc., which are used as dry cleaning solvents are preferred. Furthermore, as the halogenated hydrocarbon solvent mentioned above, chlorine-based solvents such as tetrachloroethylene and trichloroethylene are preferred.

[0012] Claim 2The solvent used to dissolve the adhesive of the absorbent article in the method for separating and recovering the constituent materials of the absorbent article of the invention is preferably one whose specific gravity is in the range of 0.7 or more and 1.5 or less, and more preferably one which is in the range of 0.7 or more and 0.8 or less. As solvents with a specific gravity of 0.7 or higher and 1.5 or lower, for example, petroleum-based solvents containing paraffin, naphthenes, etc., which are used as dry cleaning solvents, can be used.

[0013] Claim 3 The separation and recovery step of the method for separating and recovering the constituent materials of an absorbent article according to the invention involves immersing the absorbent article in the solvent and separating the constituent materials of the absorbent article in the solvent. The constituent materials of the absorbent article, which have been dismantled in the solvent in which the adhesive has been dissolved, are separated using gravity, centrifugal force, specific gravity difference, etc., and filtration separation using a screen or the like.

[0014] Claim 4 The separation and recovery step of the method for separating and recovering the constituent materials of an absorbent article according to the invention is as follows: In the sheet separation and recovery step, the absorbent article is immersed in the solvent and separated into the sheet, pulp fibers as the absorbent body, and a superabsorbent polymer in the solvent; and in the absorbent body separation and recovery step, the absorbent body separated from the sheet is separated into the pulp fibers and the superabsorbent polymer in a solvent with a specific gravity higher than that of the superabsorbent polymer. The above sheet separation and recovery process is a process of separating the sheet from the pulp fibers and superabsorbent polymer used as absorbents by utilizing gravity, centrifugal force, specific gravity difference, etc., and filtration separation using a screen, etc., in the solvent in which the adhesive has been dismantled. Furthermore, the above-mentioned absorbent separation and recovery process is a process that separates pulp fibers from superabsorbent polymer by utilizing the flotation of superabsorbent polymer in a solvent with a specific gravity higher than that of superabsorbent polymer and filtration separation using a screen or the like.

[0015] Claim 5The separated pulp fibers and the superabsorbent polymer from the sheet in the method for separating and recovering constituent materials of the absorbent article of the invention are to be subjected to the absorbent body separation and recovery step after being dried, and the solvent in which the adhesive is dissolved is not to be mixed with the solvent used in the absorbent body separation and recovery step.

[0016] Claim 6 The solvent used in the absorbent body separation and recovery step in the method for separating and recovering constituent materials of the absorbent article of the invention has a specific gravity within the range of 1.6 or more and 1.8 or less. Examples of the solvent having a specific gravity of 1.6 or more and 1.8 or less include chlorine-based halogenated hydrocarbon solvents such as tetrachloroethylene used as a dry cleaning solvent.

[0017] Claim 7 The method for separating and recovering constituent materials of the absorbent article of the invention immerses an unused absorbent article formed by surrounding an absorbent body with a sheet and joining the sheet with an adhesive in a solvent in a solvent treatment step to dissolve the adhesive in the solvent, dries the constituent materials of the absorbent article from which the adhesive has been dissolved and removed in a drying step, and separates and recovers the dried constituent materials of the absorbent article in a separation and recovery step.

[0018] The above solvent treatment step is a step of dissolving and removing the adhesive of the absorbent article with a solvent by immersing an absorbent article formed by surrounding an absorbent body containing pulp fibers, superabsorbent polymer, etc. with a sheet and joining the sheet with an adhesive in the solvent. The above drying step is a step of volatilizing the solvent adhering thereto and removing the solvent by drying the constituent materials of the absorbent article dissociated by dissolution and removal of the adhesive. The above separation and recovery step is a step of separating and recovering the sheet of the absorbent article dissociated by dissolution and removal of the adhesive and the constituent materials such as the absorbent body containing pulp fibers, superabsorbent polymer, etc., and for example, separating the constituent materials by utilizing the dimensional difference, specific gravity difference, etc. of the constituent materials.

[0019] Claim 8The method for separating and recovering the constituent materials of an absorbent article according to the invention further involves distilling the solvent in which the adhesive is dissolved in the adhesive during the adhesive separation and recovery step, thereby separating and recovering the adhesive from the solvent. The above adhesive separation and recovery process involves separating and recovering the adhesive from the solvent by distilling the solvent in which the adhesive has been dissolved by immersing an absorbent article, thereby precipitating the adhesive.

[0020] Claim 9 The method for separating and recovering the constituent materials of an absorbent article according to the invention involves recovering the solvent from which the adhesive has been separated and reusing it as a solvent for immersion treatment of the absorbent article in the solvent treatment step. The distilled solvent gas is cooled, liquefied, and then preferably purified by filter filtration before being reused.

[0021] Claim 10 The invention provides a separation and recovery apparatus for the constituent materials of an absorbent article, in which an unused absorbent article, which is formed by surrounding an absorbent body with a sheet and joining the sheets with an adhesive, is immersed in a solvent in a solvent treatment section to dissolve the adhesive in the solvent, the constituent materials of the absorbent article that have been dissociated by the dissolution of the adhesive in the solvent are separated and recovered by a separation and recovery means, and the separated and recovered constituent materials are dried by a drying means.

[0022] The above-mentioned solvent treatment method involves immersing an absorbent article, which is formed by surrounding an absorbent material containing pulp fibers and a superabsorbent polymer with a sheet and joining the sheets with an adhesive, in a solvent to dissolve and remove the adhesive from the absorbent article using the solvent.

[0023] Here, the absorbent article is, for example, an article used to absorb liquids discharged from a person or animal, such as a disposable diaper, sanitary napkin, incontinence pad, panty liner, or pet sheet, and is formed by, for example, enclosing an absorbent body containing pulp fibers and a superabsorbent polymer with a sheet and joining the opposing sheets together with a hot melt adhesive. Furthermore, the unused absorbent materials mentioned above refer to loss items such as off-spec products (defective products) and trimmed scraps (cut edges) that are generated during the manufacturing process of absorbent materials such as disposable diapers. Furthermore, the above-mentioned solvent can be any solvent capable of dissolving the hot-melt adhesive used in absorbent articles. Preferably, a halogenated hydrocarbon solvent such as a petroleum-based solvent containing paraffin, naphthene, etc., or a chlorine-based solvent such as tetrachloroethylene or trichloroethylene is used.

[0024] The above separation and recovery means separates and recovers the constituent materials of absorbent articles, such as sheets of absorbent material dissociated by dissolving and removing the adhesive, and absorbent materials including pulp fibers and superabsorbent polymers. For example, the constituent materials are separated by utilizing differences in dimensions, specific gravity, etc. The above drying method removes the solvent adhering to the constituent materials by volatilizing them through vacuum drying, hot air drying, etc.

[0025] Claim 10 The solvent used to dissolve the adhesive of the absorbent article in the separation and recovery apparatus for the constituent materials of the absorbent article of the invention is preferably a petroleum-based and / or halogenated hydrocarbon-based dry cleaning solvent. As the above-mentioned petroleum-based solvent, petroleum-based solvents containing paraffin, naphthenes, etc., which are used as dry cleaning solvents are preferred. Furthermore, as the halogenated hydrocarbon solvent mentioned above, chlorine-based solvents such as tetrachloroethylene and trichloroethylene are preferred.

[0026] Claim 11 The solvent used to dissolve the adhesive of the absorbent article in the separation and recovery apparatus for the constituent materials of the absorbent article of the invention is preferably one whose specific gravity is in the range of 0.7 or more and 1.5 or less, and more preferably one which is in the range of 0.7 or more and 0.8 or less. As solvents with a specific gravity of 0.7 or higher and 1.5 or lower, for example, petroleum-based solvents containing paraffin, naphthenes, etc., which are used as dry cleaning solvents, can be used.

[0027] Claim 12 The separation and recovery means of the separation and recovery apparatus for the constituent materials of an absorbent article of the invention separates the constituent materials of the absorbent article in the solvent in which the absorbent article has been immersed, and separates the constituent materials of the absorbent article that have been dismantled in the solvent in which the adhesive has been dissolved, using gravity, centrifugal force, specific gravity difference, etc., and filtration separation using a screen or the like.

[0028] Claim 13 The separation and recovery means of the separation and recovery apparatus for the constituent materials of the absorbent article of the invention separates the absorbent article into the sheet and the pulp fibers and superabsorbent polymer in the solvent by immersing the absorbent article in the solvent using the sheet separation and recovery means, and separates the absorbent separated from the sheet into the pulp fibers and superabsorbent polymer in a solvent with a specific gravity higher than that of the superabsorbent polymer using the absorbent separation and recovery means. The above-described sheet separation and recovery means separates the sheet from the pulp fibers and superabsorbent polymer used as absorbents by utilizing gravity, centrifugal force, specific gravity difference, etc., and filtration separation using a screen or the like, from the constituent materials of the absorbent article that have been dismantled in a solvent in which the adhesive has been dissolved. Furthermore, the above-mentioned absorbent separation and recovery means separates pulp fibers from the superabsorbent polymer by utilizing the flotation of the superabsorbent polymer in a solvent with a specific gravity higher than that of the superabsorbent polymer and filtration separation using a screen or the like.

[0029] Claim 14 In the separation and recovery apparatus for the constituent materials of the absorbent article of the invention, the sheet, the pulp fibers, and the superabsorbent polymer separated from it are dried before being separated by the absorbent material separation and recovery means, and the solvent in which the adhesive is dissolved is not mixed with the solvent used in the absorbent material separation and recovery means.

[0030] Claim 15 The solvent used in the absorbent separation and recovery means of the separation and recovery apparatus for the constituent materials of the absorbent article of the invention has a specific gravity within the range of 1.6 or more and 1.8 or less. As solvents with a specific gravity of 1.6 or higher and 1.8 or lower, for example, chlorine-based halogenated hydrocarbon solvents such as tetrachloroethylene, which are used as dry cleaning solvents, can be used.

[0031] Claim 16 The invention provides a separation and recovery apparatus for the constituent materials of an absorbent article, which involves immersing an unused absorbent article, in a solvent treatment section, in a solvent to dissolve the adhesive in the solvent, drying the constituent materials of the absorbent article from which the adhesive has been dissolved and removed by a drying means, and separating and recovering the dried constituent materials of the absorbent article by a separation and recovery means.

[0032] The above-mentioned solvent treatment method involves immersing an absorbent article, which is formed by surrounding an absorbent material containing pulp fibers and a superabsorbent polymer with a sheet and joining the sheets with an adhesive, in a solvent to dissolve and remove the adhesive from the absorbent article using the solvent. The above drying method involves removing the solvent adhering to the constituent materials of the absorbent article, which have been dissociated by the dissolution and removal of the adhesive, by volatilizing them through vacuum drying, hot air drying, or the like. The above-mentioned separation and recovery means separates and recovers the constituent materials of absorbent articles, such as sheets of absorbent material that have been dissociated and dried by dissolving and removing the adhesive, and absorbent materials containing pulp fibers and superabsorbent polymers, for example, by utilizing differences in dimensions, specific gravity, etc. of the constituent materials.

[0033] Claim 17 The separation and recovery apparatus for the constituent materials of the absorbent article of the invention further includes an adhesive separation and recovery means which distills the solvent in which the adhesive is dissolved, thereby separating and recovering the adhesive from the solvent. The above adhesive separation and recovery means separates and recovers the adhesive from the solvent by distilling the solvent in which the adhesive has been dissolved by immersing an absorbent article, thereby precipitating the adhesive.

[0034] Claim 18The separation and recovery apparatus for the constituent materials of the absorbent article of the present invention returns the solvent from which the adhesive has been separated by a solvent circulation path back to the solvent treatment section and reuses it as a solvent for immersion treatment of the absorbent article. The distilled solvent gas is cooled, liquefied, and then preferably purified by filter filtration before being reused.

[0035] Claim 19 The invention provides a method for manufacturing recycled unused absorbent materials, which involves, in a solvent treatment step, immersing an unused absorbent article, which is made by joining sheets containing pulp fibers and a superabsorbent polymer as absorbents with an adhesive, in a solvent to dissolve the adhesive in the solvent; in a separation and recovery step, separating and recovering the sheet, pulp fibers, and superabsorbent polymer from the absorbent article from which the adhesive has been dissolved and removed; and in a drying step, drying the separated and recovered pulp fibers and superabsorbent polymer.

[0036] The above solvent treatment process involves immersing an absorbent article, which is made by surrounding an absorbent material of pulp fibers and a superabsorbent polymer with a sheet and joining the sheets with an adhesive, in a solvent to dissolve and remove the adhesive from the absorbent article using the solvent.

[0037] Here, the absorbent article is, for example, an article used to absorb liquids discharged from a person or animal, such as a disposable diaper, sanitary napkin, incontinence pad, panty liner, or pet sheet, and is formed by, for example, enclosing an absorbent body containing pulp fibers and a superabsorbent polymer with a sheet and joining the opposing sheets together with a hot melt adhesive. Furthermore, the unused absorbent materials mentioned above refer to loss items such as off-spec products (defective products) and trimmed scraps (cut edges) that are generated during the manufacturing process of absorbent materials such as disposable diapers. Furthermore, the above-mentioned solvent can be any solvent capable of dissolving the hot-melt adhesive used in absorbent articles. Preferably, a halogenated hydrocarbon solvent such as a petroleum-based solvent containing paraffin, naphthene, etc., or a chlorine-based solvent such as tetrachloroethylene or trichloroethylene is used.

[0038] The above separation and recovery process involves separating and recovering the absorbent material sheet, pulp fibers, and superabsorbent polymer that have been dissociated by dissolving and removing the adhesive. For example, the sheet, pulp fibers, and superabsorbent polymer are separated by utilizing differences in dimensions, specific gravity, etc. The above drying process involves drying at least the separated pulp fibers and superabsorbent polymer to volatilize the solvent adhering to the pulp fibers and superabsorbent polymer, thereby removing the solvent.

[0039] Claim 20 The invention provides a method for manufacturing recycled unused absorbent materials, which involves immersing an unused absorbent article, formed by joining sheets containing pulp fibers and a superabsorbent polymer as absorbents with an adhesive, in a solvent treatment step to dissolve the adhesive in the solvent; drying the constituent materials of the absorbent article from which the adhesive has been dissolved and removed in a drying step; and separating and recovering the pulp fibers and the superabsorbent polymer from the dried absorbent article in a separation and recovery step.

[0040] The above solvent treatment process involves immersing an absorbent article, which is made by surrounding an absorbent material of pulp fibers and a superabsorbent polymer with a sheet and joining the sheets with an adhesive, in a solvent to dissolve and remove the adhesive from the absorbent article using the solvent. The above drying process involves drying the constituent materials of the absorbent article, which have been dissociated by the dissolution and removal of the adhesive, thereby volatilizing and removing the solvent adhering to them. The above separation and recovery process involves separating and recovering the absorbent material sheet, pulp fibers, and superabsorbent polymer after dissociation and removal of the adhesive and subsequent drying. For example, the constituent materials are separated by utilizing differences in dimensions, specific gravity, etc., between the sheet, pulp fibers, and superabsorbent polymer. [Effects of the Invention]

[0041] According to the method for separating and recovering the constituent materials of an absorbent article according to claim 1, in a solvent treatment step, an unused absorbent article, which is made by joining sheets containing an absorbent material with an adhesive, is immersed in a solvent to dissolve the adhesive in the solvent. Then, in a separation and recovery step, the constituent materials of the absorbent article from which the adhesive has been dissolved and removed are separated and recovered, and in a drying step, the separated and recovered constituent materials are dried.

[0042] In this method, the adhesive joining the components of unused absorbent articles is dissolved in a solvent and removed from the absorbent articles, thereby dismantling the absorbent articles and separating and recovering their constituent materials. As a result, the absorbent articles are easily decomposed due to the dissolution and removal of the adhesive, and the dissociation and separation of their constituent materials becomes easier. Therefore, it is possible to improve the recovery rate of constituent materials of unused absorbent articles. In particular, by removing the adhesive from the absorbent articles, the constituent materials of the absorbent articles can be accurately separated and recovered without applying a large amount of energy that would cause the constituent materials such as superabsorbent polymers to be subdivided. That is, the constituent materials such as superabsorbent polymers of the absorbent articles can be separated and recovered without subdividing them. Therefore, the constituent materials of absorbent articles can be separated and recovered with high quality. In particular, the superabsorbent polymers and pulp fibers of the absorbent material can be separated and recovered while maintaining the original properties of the absorbent material without being finely granulated or pulverized, and since the adhesive is also removed, it is suitable for material recycling and is also suitable for recycling the absorbent articles as absorbents.

[0043] Claim 1 According to the method for separating and recovering the constituent materials of an absorbent article in this invention, since the solvent is a petroleum-based and / or halogenated hydrocarbon-based dry cleaning solvent, it is less susceptible to oxidative degradation and suitable for repeated reuse, and the solvent odor is less likely to remain in the separated and recovered constituent materials. Therefore , low It can be made more cost-effective, and the separated and recovered constituent materials can be recycled for a wide range of uses.

[0044] Claim 2According to the method for separating and recovering the constituent materials of an absorbent article based on the invention, the solvent used to immerse the absorbent article has a specific gravity in the range of 0.7 to 1.5, so the absorbent material settles in the solvent after the constituent materials of the absorbent article have been immersed in it. Therefore, the sheet and the absorbent material can be accurately separated in the solvent by filtration separation using a screen or the like under low load conditions and with energy savings. Thus, in addition to the effects described in claim 1, the sheet and the absorbent material can be recovered in high quality at low cost and with energy savings, and the recovery rate can be improved, as the sheet and the absorbent material can be accurately separated under low cost, energy savings, and low load conditions.

[0045] Claim 3 According to the method for separating and recovering the constituent materials of an absorbent article in the invention, the separation and recovery step involves immersing the absorbent article in the solvent and separating the constituent materials of the absorbent article in the solvent. This separation is performed by using gravity, centrifugal force, specific gravity difference, and filtration separation using a screen or the like, to separate the constituent materials of the absorbent article that have been disassembled in the solvent in which the adhesive has been dissolved. Therefore, because the separation is wet, the sheet and absorbent can be separated accurately under low-load conditions and with energy savings. Thus, in addition to the effects described in claim 1, the sheet and absorbent can be recovered in high quality at low cost and with energy savings, and the recovery rate can be improved, as the sheet and absorbent can be separated accurately under low-cost, energy-saving, and low-load conditions.

[0046] Claim 4According to the method for separating and recovering the constituent materials of an absorbent article according to the invention, the separation and recovery step includes a sheet separation and recovery step in which the absorbent article is immersed in the solvent and separated into the sheet, pulp fibers as the absorbent body, and superabsorbent polymer in the solvent, and an absorbent body separation and recovery step in which the absorbent body separated from the sheet is separated into the pulp fibers and superabsorbent polymer in a solvent with a specific gravity higher than the solvent in which it was immersed. First, in the sheet separation and recovery step, the constituent materials of the absorbent article dismantled in the solvent in which the adhesive is dissolved are separated into the sheet, pulp fibers as the absorbent body, and superabsorbent polymer by utilizing gravity, centrifugal force, specific gravity difference, etc., and filtration separation using a screen, etc. Then, in the subsequent absorbent body separation and recovery step, the pulp fibers and superabsorbent polymer are separated by utilizing the flotation of the superabsorbent polymer in a solvent with a specific gravity higher than the superabsorbent polymer and filtration separation using a screen, etc. Therefore, since the separation is performed wet, the sheet, pulp fibers, and superabsorbent polymer can be accurately separated under conditions that are particularly low-impact on the superabsorbent polymer and energy-saving. Thus, in addition to the effects described in claim 1, the sheet, pulp fibers, and superabsorbent polymer can be accurately separated under low-cost, energy-saving, and low-impact conditions, and the pulp fibers and superabsorbent polymer can be recovered in high quality at low cost and energy saving, and the recovery rate can be improved.

[0047] Claim 5 According to the method for separating and recovering the constituent materials of an absorbent article according to the invention, the pulp fibers and the superabsorbent polymer separated from the sheet are dried before being subjected to the absorbent material separation and recovery step. Therefore, the solvent in which the adhesive adhering to the pulp fibers and the superabsorbent polymer is dissolved does not mix with the solvent used to separate the pulp fibers and the superabsorbent polymer in the absorbent material separation and recovery step. Thus, even when the solvent used to separate the pulp fibers and the superabsorbent polymer in the absorbent material separation and recovery step is recovered and reused, purification to separate the solvent in which the adhesive is dissolved is not required. 4 In addition to the effects described above, it can also reduce costs.

[0048] Claim 6According to the method for separating and recovering the constituent materials of an absorbent article in the invention, the solvent used in the absorbent separation and recovery step has a specific gravity in the range of 1.6 to 1.8, so the superabsorbent polymer floats quickly in the solvent, thereby improving separation accuracy and allowing the separation and recovery process to be completed in a short time. Therefore, the claim 4 In addition to the effects described above, separation efficiency can be improved.

[0049] Claim 7 According to the method for separating and recovering the constituent materials of an absorbent article based on the invention, in a solvent treatment step, an unused absorbent article, which is made by joining sheets containing an absorbent material with an adhesive, is immersed in a solvent to dissolve the adhesive in the solvent; in a drying step, the absorbent article from which the adhesive has been removed by dissolution in the solvent is dried; and in a separation and recovery step, the constituent materials of the dried absorbent article are separated and recovered.

[0050] In this method, the adhesive joining the components of unused absorbent articles is dissolved in a solvent and removed from the absorbent articles, thereby dismantling the absorbent articles and separating and recovering their constituent materials. As a result, the absorbent articles are easily decomposed as the adhesive is dissolved and removed, and the dissociation and separation of their constituent materials becomes easier. Therefore, it is possible to improve the recovery rate of constituent materials of unused absorbent articles. In particular, by removing the adhesive from the absorbent articles, the constituent materials of the absorbent articles can be accurately separated and recovered without applying a large amount of energy that would cause the constituent materials such as superabsorbent polymers to be subdivided. That is, the constituent materials such as superabsorbent polymers of the absorbent articles can be separated and recovered without subdividing them. Therefore, high-quality separation and recovery are possible. In particular, the superabsorbent polymers and pulp fibers of the absorbent material can be separated and recovered while maintaining the original properties of the absorbent article as an absorbent material without being finely granulated or pulverized, and since the adhesive is also removed, it is suitable for material recycling and is also suitable for recycling the absorbent articles as absorbent materials.

[0051] Claim 8The method for separating and recovering the constituent materials of an absorbent article according to the invention further comprises an adhesive separation and recovery step of evaporating the solvent in which the adhesive has dissolved and separating and recovering the adhesive, Claim 1 or Claim 7 In addition to the effects described above, the adhesives used in absorbent materials can be recycled, allowing for even more efficient use of resources.

[0052] Claim 9 According to the method for separating and recovering the constituent materials of an absorbent article according to the invention, the solvent separated from the adhesive in the adhesive separation and recovery step is reused as a solvent for immersing the absorbent article in the solvent treatment step, therefore, 8 In addition to the effects described above, it can reduce environmental impact and lower costs.

[0053] Claim 10 According to the separation and recovery apparatus for the constituent materials of an absorbent article in the invention, an unused absorbent article, which is made by joining sheets enclosing an absorbent material with an adhesive, is immersed in a solvent in a solvent in a solvent treatment section to dissolve the adhesive in the solvent, the constituent materials of the absorbent article from which the adhesive has been dissolved and removed by a separation means are separated and recovered, and the separated and recovered constituent materials are dried by a drying means.

[0054] In this method, the adhesive joining the components of unused absorbent articles is dissolved in a solvent and removed from the absorbent articles, thereby dismantling the absorbent articles and separating and recovering their constituent materials. As a result, the absorbent articles are easily decomposed as the adhesive is dissolved and removed, and the dissociation and separation of their constituent materials becomes easier. Therefore, it is possible to improve the recovery rate of constituent materials of unused absorbent articles. In particular, by removing the adhesive from the absorbent articles, the constituent materials of the absorbent articles can be accurately separated and recovered without applying a large amount of energy that would cause the constituent materials such as superabsorbent polymers to be subdivided. That is, the constituent materials such as superabsorbent polymers of the absorbent articles can be separated and recovered without subdividing them. Therefore, high-quality separation and recovery are possible. In particular, the superabsorbent polymers and pulp fibers of the absorbent material can be separated and recovered while maintaining the original properties of the absorbent article as an absorbent material without being pulverized or finely powdered, and since the adhesive is also removed, it is suitable for material recycling and is also suitable for recycling the absorbent articles as absorbent materials.

[0055] Claim 10 According to the separation and recovery apparatus for the constituent materials of an absorbent article in this invention, since the solvent is a petroleum-based and / or halogenated hydrocarbon-based dry cleaning solvent, it is less susceptible to oxidative degradation and suitable for repeated reuse, and the solvent odor is less likely to remain in the separated and recovered constituent materials. Therefore , low It can be made more cost-effective, and the separated and recovered constituent materials can be recycled for a wide range of uses.

[0056] Claim 11 According to the separation and recovery apparatus for the constituent materials of an absorbent article, the solvent used to immerse the absorbent article has a specific gravity in the range of 0.7 to 1.5, so the absorbent material settles in the solvent after the constituent materials of the absorbent article have been immersed in it. Therefore, the sheet and the absorbent material can be accurately separated in the solvent under low-impact conditions and energy-saving conditions, such as filtration separation using a screen. Thus, the sheet and the absorbent material can be accurately separated under low-cost, energy-saving, and low-impact conditions, thus fulfilling the claim. 10In addition to the effects described above, it is possible to recover absorbers with high quality at low cost and with energy savings, and to improve the recovery rate.

[0057] Claim 12 According to the separation and recovery apparatus for the constituent materials of an absorbent article in the invention, the separation and recovery means separates the constituent materials of the absorbent article in the solvent in which the absorbent article has been immersed. Therefore, the constituent materials of the absorbent article, which have been disassembled in the solvent in which the adhesive has been dissolved, are separated using gravity, centrifugal force, specific gravity difference, etc., and filtration separation using a screen, etc. Therefore, since the separation is wet, the sheet and absorbent can be separated accurately under low load conditions and energy saving conditions. Thus, the claim is made possible by being able to separate the sheet and absorbent accurately under low cost, energy saving, and low load conditions. 10 In addition to the effects described above, it is possible to recover absorbers with high quality at low cost and with energy savings, and to improve the recovery rate.

[0058] Claim 13According to the separation and recovery apparatus for the constituent materials of an absorbent article in the invention, the separation and recovery means includes a sheet separation and recovery means that separates the sheet, pulp fibers as absorbents, and superabsorbent polymer in the solvent in which the absorbent article has been immersed, and an absorbent material separation and recovery means that separates the absorbent material separated from the sheet into pulp fibers and superabsorbent polymer in a solvent with a specific gravity higher than the solvent in which it was immersed. First, the sheet separation and recovery means separates the sheet, pulp fibers as absorbents, and superabsorbent polymer from the constituent materials of the absorbent article that have been dismantled in the solvent in which the adhesive has been dissolved, using gravity, centrifugal force, specific gravity difference, etc., and filtration separation using a screen, etc. Then, the subsequent absorbent material separation and recovery means separates the pulp fibers and superabsorbent polymer by using the flotation of the superabsorbent polymer in a solvent with a specific gravity higher than the superabsorbent polymer and filtration separation using a screen, etc. Therefore, since the separation is performed wet, and in particular under low-impact conditions and energy-saving conditions, the sheet, pulp fibers, and superabsorbent polymer can be separated accurately. Thus, the claim is made possible by enabling the accurate separation of the sheet, pulp fibers, and superabsorbent polymer under low-cost, energy-saving, and low-impact conditions. 10 In addition to the effects described above, it is possible to recover pulp fibers and superabsorbent polymers in a high-quality manner at low cost and with energy savings, and to improve the recovery rate.

[0059] Claim 14 According to the separation and recovery apparatus for the constituent materials of an absorbent article according to the invention, the pulp fibers and superabsorbent polymer separated from the sheet are dried before being subjected to the absorbent material separation and recovery means. Therefore, the solvent in which the adhesive adhering to the pulp fibers and superabsorbent polymer is dissolved does not mix with the solvent used to separate the pulp fibers and superabsorbent polymer in the absorbent material separation and recovery process. Thus, even when the solvent used to separate the pulp fibers and superabsorbent polymer in the absorbent material separation and recovery means is recovered and reused, purification to separate the solvent in which the adhesive is dissolved is not required. 13 In addition to the effects described above, it can also reduce costs.

[0060] Claim15 According to the separation and recovery apparatus for the constituent materials of an absorbent article according to the invention, the solvent used in the absorbent separation and recovery process has a specific gravity in the range of 1.6 to 1.8, so the superabsorbent polymer floats quickly in the solvent, thereby improving separation accuracy and allowing the separation and recovery process to be completed in a short time. Therefore, the claim 13 In addition to the effects described above, separation efficiency can be improved.

[0061] Claim 16 According to the separation and recovery apparatus for the constituent materials of an absorbent article in the invention, in the solvent treatment section, an unused absorbent article, which is made by joining sheets enclosing an absorbent with an adhesive, is immersed in a solvent to dissolve the adhesive in the solvent, the absorbent article from which the adhesive has been removed by dissolution in the solvent is dried by a drying means, and the constituent materials of the dried absorbent article are separated and recovered by a separation and recovery means.

[0062] In this method, the adhesive joining the components of unused absorbent articles is dissolved in a solvent and removed from the absorbent articles, thereby dismantling the absorbent articles and separating and recovering their constituent materials. As a result, the absorbent articles are easily decomposed due to the dissolution and removal of the adhesive, and the dissociation and separation of their constituent materials becomes easier. Therefore, it is possible to improve the recovery rate of constituent materials of unused absorbent articles. In particular, by removing the adhesive from the absorbent articles, the constituent materials of the absorbent articles can be accurately separated and recovered without applying a large amount of energy that would cause the constituent materials such as superabsorbent polymers to be subdivided. That is, the constituent materials such as superabsorbent polymers of the absorbent articles can be separated and recovered without subdividing them. Therefore, the constituent materials of absorbent articles can be separated and recovered with high quality. In particular, the superabsorbent polymers and pulp fibers of the absorbent material can be separated and recovered while maintaining the original properties of the absorbent material without being finely granulated or pulverized, and since the adhesive is also removed, it is suitable for material recycling and is also suitable for recycling the absorbent articles as absorbents.

[0063] Claim 17The separation and recovery apparatus for the constituent materials of an absorbent article according to the invention further comprises an adhesive separation and recovery means for evaporating the solvent in which the adhesive has dissolved and separating and recovering the adhesive, Claim 10 or Claim 16 In addition to the effects described above, the adhesives used in absorbent materials can be recycled, allowing for more efficient use of resources.

[0064] Claim 18 The method for separating and recovering the constituent materials of an absorbent article according to the invention comprises a solvent circulation path that allows the solvent separated from the adhesive by the adhesive separation and recovery means to be reused as a solvent for immersing the absorbent article in the solvent treatment section, therefore, 17 In addition to the effects described above, it can reduce environmental impact and lower costs.

[0065] Claim 19 The method for manufacturing a recycled unused absorbent according to the invention involves, in a solvent treatment step, immersing an unused absorbent article, which is made by joining sheets containing pulp fibers and a superabsorbent polymer as absorbents with an adhesive, in a solvent to dissolve the adhesive in the solvent; in a separation and recovery step, separating and recovering the sheet, pulp fibers, and superabsorbent polymer of the absorbent article from which the adhesive has been dissolved and removed; and in a drying step, drying the separated and recovered pulp fibers and superabsorbent polymer.

[0066] In this method, the adhesive joining the components of unused absorbent articles is dissolved in a solvent and removed from the absorbent articles, thereby dismantling the absorbent articles and separating and recovering their constituent materials. As a result of dissolving and removing the adhesive from the absorbent articles, the absorbent articles are easily decomposed, and the pulp fibers and superabsorbent polymer are easily dissociated and separated. Therefore, it is possible to improve the recovery rate of unused absorbent pulp fibers and superabsorbent polymer. In particular, by removing the adhesive from the absorbent articles, the pulp fibers and superabsorbent polymer of the absorbent material can be accurately separated and recovered without applying a large amount of energy that would cause the pulp fibers and superabsorbent polymer to be subdivided. That is, the pulp fibers and superabsorbent polymer of the absorbent material can be separated and recovered without subdividing them. Therefore, the pulp fibers and superabsorbent polymer of the absorbent material can be separated and recovered with high quality. In particular, the superabsorbent polymer and pulp fibers of the absorbent material can be separated and recovered while maintaining their original properties as absorbent material of the absorbent article without being pulverized or finely powdered. Furthermore, since the adhesive is also removed, it is suitable for material recycling and is also suitable for recycling absorbent material of the absorbent article.

[0067] Claim 20 The method for manufacturing recycled unused absorbent materials according to the invention involves, in a solvent treatment step, immersing an unused absorbent article, which is made by joining sheets containing pulp fibers and a superabsorbent polymer as absorbents with an adhesive, in a solvent to dissolve the adhesive in the solvent; in a drying step, drying the absorbent article from which the adhesive has been dissolved and removed; and in a separation and recovery step, separating and recovering the pulp fibers and the superabsorbent polymer from the dried absorbent article.

[0068] In this method, the adhesive joining the components of unused absorbent articles is dissolved in a solvent and removed from the absorbent articles, thereby dismantling the absorbent articles and separating and recovering their constituent materials. As a result of dissolving and removing the adhesive from the absorbent articles, the absorbent articles are easily decomposed, and the pulp fibers and superabsorbent polymer are easily dissociated and separated. Therefore, it is possible to improve the recovery rate of unused absorbent pulp fibers and superabsorbent polymer. In particular, by removing the adhesive from the absorbent articles, the pulp fibers and superabsorbent polymer of the absorbent material can be accurately separated and recovered without applying a large amount of energy that would cause the pulp fibers and superabsorbent polymer to be subdivided. That is, the pulp fibers and superabsorbent polymer of the absorbent material can be separated and recovered without subdividing them. Therefore, the pulp fibers and superabsorbent polymer of the absorbent material can be separated and recovered with high quality. In particular, the superabsorbent polymer and pulp fibers of the absorbent material can be separated and recovered while maintaining their original properties as absorbent material of the absorbent article without being pulverized or finely powdered. Furthermore, since the adhesive is also removed, it is suitable for material recycling and is also suitable for recycling absorbent material of the absorbent article. [Brief explanation of the drawing]

[0069] [Figure 1] Figure 1 is an explanatory diagram illustrating the constituent materials of a diaper, which is an example of an absorbent article. [Figure 2] Figure 2 is a flowchart showing the method for separating and recovering the constituent materials of the absorbent article according to this embodiment. [Figure 3] Figure 3 is a conceptual diagram illustrating Example 1 of the separation and recovery method and separation and recovery apparatus for the constituent materials of an absorbent article according to this embodiment. [Figure 4] Figure 4 is a schematic diagram illustrating the sheet separation and recovery process and sheet separation and recovery means of Example 1 of the separation and recovery method and separation and recovery apparatus for the constituent materials of an absorbent article according to this embodiment. [Figure 5] Figure 5 is a schematic diagram illustrating the absorbent material separation and recovery process and absorbent material separation and recovery means of Example 1 of the method for separating and recovering the constituent materials of an absorbent article according to this embodiment. [Figure 6]Figure 6 is a conceptual diagram illustrating Example 2 of the separation and recovery method and separation and recovery apparatus for the constituent materials of an absorbent article according to this embodiment. [Figure 7] Figure 7 is a flowchart showing a method for separating and recovering the constituent materials of an absorbent article according to a modified example of this embodiment. [Modes for carrying out the invention]

[0070] Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the embodiments and their modifications, the same symbols and reference numerals represent the same or corresponding functional parts, and the same symbols and reference numerals in the embodiments and modifications represent functional parts common to those embodiments and modifications; therefore, redundant detailed explanations are omitted here.

[0071] [Embodiment] First, the absorbent article to be processed for the separation and recovery of its constituent materials in this embodiment will be described with reference to Figure 1. Absorbent articles such as disposable diapers, sanitary napkins, incontinence (urine absorption) pads, panty liners, and pet sheets mainly consist of an absorbent body 10 made of pulp fibers 11 and super absorbent polymer 12 (SAP), which is wrapped in sheets 20 such as a surface sheet 21 and a back sheet 22 made of nonwoven fabric or thermoplastic resin film, and the opposing surface sheet 21 and back sheet 22 are joined together with a hot melt adhesive.

[0072] The absorbent body 10, which is placed between the surface sheet 21 and the back sheet 22, is composed of pulp fibers 11 and superabsorbent polymer (SAP) 12 as absorbent materials. As pulp fibers 11 (fibrous pulp), mainly cellulosic fibers such as wood pulp (coniferous pulp, hardwood pulp), cross-linked pulp, non-wood pulp, regenerated cellulose, semi-synthetic cellulose, cellulose nanofiber (CNF), cellulose acetate, rayon, and cotton are used, but synthetic fibers may also be included, and are used in the absorbent body 10 in the form of fluff pulp (cotton-like pulp), which is a chemical pulp. The fiber length is on average a few millimeters, for example about 1 mm to 5 mm, and the fiber diameter is on average a few tens of micrometers, for example about 10 to 50 micrometers.

[0073] Furthermore, the superabsorbent polymer (hereinafter referred to as "SAP") 12 is a hydrophilic polymer (water-soluble polymer) with a crosslinked structure, such as a synthetic polymer system including sodium polyacrylate, polysulfonate, polyvinyl alcohol, polyacrylamide, polyoxyethylene, polyaspartate, polyglutamate, polyalginate, and maleate anhydride, as well as starch, cellulose, and amino acid systems. For example, sodium polyacrylate, carboxymethylcellulose (CMC), starch-acrylic acid (salt) graft copolymer, saponified starch-acrylonitrile copolymer, crosslinked sodium carboxymethylcellulose, polyvinyl alcohol (PVA), and PVA / sodium polyacrylate are used, but typically polymers or copolymers of acrylic acid or alkali metal acrylate salts are used. Usually, particulate form is used as a water-swellable, water-insoluble polymer gelling agent, but it may also be fibrous. The particle size of particulate SAP in its dry state is, for example, about 150 to 600 μm.

[0074] The surface sheet (top sheet) 21 is a surface material, and for example, nonwoven fabric or film is used. Specifically, liquid-permeable nonwoven fabric, synthetic resin film, or laminates (composite sheets) thereof are used. Furthermore, the back sheet 22 is a waterproofing material, and for example, a porous polyolefin resin or other synthetic resin film containing fillers (inorganic fillers such as calcium carbonate, barium sulfate, magnesium oxide, barium carbonate, talc, silica, kaolin, mica, clay, titanium dioxide, zinc oxide, pigments, etc.) and having fine pores is used. In other words, a synthetic resin film that does not allow liquid to pass through and is breathable and moisture permeable, or a synthetic resin film that is not breathable is used.

[0075] Examples of nonwoven fabrics used include polyolefin-based nonwoven fabrics such as polypropylene and polyethylene, polyester-based nonwoven fabrics such as polyethylene terephthalate and polybutylene terephthalate, polyamide-based nonwoven fabrics such as 6-nylon and 6,6-nylon, and rayon nonwoven fabrics. One example is the use of air-through nonwoven fabrics, which are made by bonding composite fibers with hot air. For example, thermoplastic resin films such as polyethylene or other polyolefin films are used as the film.

[0076] Furthermore, depending on the type of absorbent article, a sheet-like absorbent paper 23 may be placed between the surface sheet (top sheet) 21 and the absorbent body 10, which consists of pulp fibers 11 and a superabsorbent polymer 12. For example, a polyolefin nonwoven fabric may be used as the absorbent paper 23. In addition, an outer sheet made of breathable nonwoven fabric or the like may be provided on the side of the back sheet 22 opposite to the side where the absorbent material 10 is installed. In addition, side sheets 24 to prevent leakage may be provided on both sides in the width direction of the absorbent article, and for these parts, for example, water-repellent treated nonwoven fabric (e.g., polyolefin-based nonwoven fabric, polyurethane nonwoven fabric, etc.), breathable synthetic resin film (polyolefin-based film, styrene-based elastomer film, etc.), or elastic material thread elastic 25 (spandex, urethane rubber, natural rubber, synthetic rubber, etc.) may be used. In addition, adhesive tapes (hook-and-loop fasteners) made of polyolefins such as polypropylene or synthetic rubber may be used as fastening materials, and cellulose nanofibers (CNF) with silver ions or fragrances that have deodorizing and antibacterial effects may be used as pulp fibers 11.

[0077] Thus, the absorbent article that is subject to separation and recovery of its constituent materials consists of an absorbent body 10 made of pulp fibers 11 and SAP 12, and sheets 20 such as a surface sheet 21 made of film or nonwoven fabric, a back sheet 22, absorbent paper 23, and side sheets 24, and these constituent materials are joined together with hot melt adhesive. Hot melt adhesives typically contain a base polymer, tackifier, and plasticizer. Examples of base polymers include styrene-based polymers such as styrene-butadiene-styrene block copolymer (SBS), styrene-ethylene-butadiene-styrene block copolymer (SEBS), styrene-isoprene-styrene block copolymer (SIS), styrene-ethylene-propylene-styrene block copolymer (SEPS), and styrene-butadiene copolymer (SBR); rubber-based polymers such as polyisoprene and natural rubber; acrylic-based polymers such as ethylene vinyl acetate copolymer; silicone-based polymers such as polydimethylsiloxane polymer; and olefin-based thermoplastic resins such as polyethylene. Tackifiers include rosin, terpene resins, and petroleum resins, while plasticizers include process oils and polybutene. Other materials may also be present, such as waxes like paraffin wax and polyethylene, fillers like calcium carbonate, titanium dioxide, and talc, and stabilizers like phenol and toluene.

[0078] To explain using diapers as an absorbent item as an example, as shown in Figure 1, diaper D as an absorbent item has a multilayer structure in which absorbent paper 23 is placed beneath a surface sheet (surface material) 21 made of nonwoven fabric, and an absorbent body 10 made of pulp fibers (flap pulp) 11 and granular SAP 12 wrapped in it is placed further beneath that, and a back sheet (waterproof material) 22 made of thermoplastic resin film is placed on the outside of the absorbent body 10 on the side opposite to the surface sheet 21, and an outer packaging material (surface material) made of nonwoven fabric (not shown) is placed on the outside of that as well. In addition, elastic gathers to prevent leakage are formed on both sides in the width direction by side sheets 24, and elastic threads 25 are placed there. In addition, a fastening material (not shown) is attached to the back sheet 22 side. In diaper D with this configuration, the absorbent material 10 made of pulp fibers 11 and SAP 12 is surrounded by a surface sheet 21 and a back sheet 22 made of nonwoven fabric or thermoplastic resin film, and the surface sheet 21 and the back sheet 22 are joined together via hot melt adhesive. The side sheets 24 that form the gathers and the outer sheet are also joined to the surface sheet 21 and the back sheet 22 via hot melt adhesive.

[0079] Next, a method and apparatus for separating and recovering off-spec products, chips, and other constituent materials generated during the manufacturing process of such absorbent articles will be described with reference to Figures 2 to 6. The method and apparatus for separating and recovering the constituent materials of absorbent articles according to this embodiment separates and recovers the constituent materials from off-spec products (defective products) and scraps (cut edges) that are generated during the manufacturing of absorbent articles; in other words, it separates and recovers the constituent materials of unused absorbent articles.

[0080] As shown in Figure 2, the separation and recovery method for separating and recovering unused absorbent article components according to this embodiment comprises: a solvent treatment step (Step S1) in which off-spec absorbent article components, scraps, etc. (hereinafter simply referred to as "work to be processed 110") extracted, recovered, and collected during the manufacturing process of absorbent article products are immersed in a solvent 120 to dissolve hot melt adhesive (hereinafter simply abbreviated as "adhesive") in the solvent 120; a separation and recovery step (Step S2) in which the components of the work to be processed 110 from which the adhesive has been removed by dissolving the adhesive in the solvent 120 are separated and recovered; and a drying step (Step S3) in which the separated and recovered components are dried.

[0081] Furthermore, as shown in Figures 3 and 6, the separation and recovery apparatus for separating and recovering the constituent materials of unused absorbent articles in this embodiment includes a solvent treatment section 510 that immerses the workpiece 110 in a solvent 120 to dissolve the adhesive in the solvent 120, a separation and recovery means consisting of screens F1, F2, solvents 120, 220, etc., for separating and recovering the constituent materials of the workpiece 110 from which the adhesive has been removed by dissolving the adhesive in the solvent 120, and a drying means for drying the separated and recovered constituent materials.

[0082] First, in the solvent treatment process (step S1), the materials to be treated 110, such as off-spec products and chips generated during the manufacturing process of absorbent articles, are immersed in the solvent 120 in the solvent treatment area 510. Furthermore, if off-spec products or scraps generated during the manufacturing process of absorbent materials are transported in bags or compressed packaging, the bags are opened or the packaging is removed to take out the material to be processed 110, and it is then put into the solvent processing unit 510. From the standpoint of preventing clogging of the inlet of the solvent processing unit 510, the material to be processed 110 may be folded before being put in or pre-cut to a size that fits into the inlet, but it is not finely defibrated, crushed, or pulverized, and is, for example, about 3 to 120 cm in length and 3 to 120 cm in width.

[0083] In the solvent treatment section 510, where unused absorbent articles such as off-spec products and chips generated during the manufacturing process of absorbent articles are immersed in a solvent 120, for example, a treatment tank containing the articles 110 and the solvent 120 is used. The articles 110 are placed into the treatment tank, and a predetermined amount of solvent 120 is added to a predetermined depth, immersing the articles 110 in the solvent 120. Preferably, in the treatment tank where the articles 110 are immersed in the solvent 120, physical shocks and external forces such as vibration, stirring, and centrifugal force (rotation) are usually applied to ensure that the solvent 120 penetrates the entire article 110 evenly and uniformly, and to promote the separation of the constituent members of the articles 110, particularly the separation of the sheet 20 and the absorbent 10 whose bond has been broken by the dissolution of the adhesive in the solvent 120, making separation easier.

[0084] Here, as solvent 120, for example, petroleum-based solvents containing paraffin, naphthenes, etc., chlorine-based solvents such as tetrachloroethylene, halogenated hydrocarbon solvents such as HCFC-225 and HFC-365, and silicone-based solvents such as cyclic or linear silicones can be used, but among these, petroleum-based or halogenated hydrocarbon dry cleaning solvents are preferred.

[0085] Suitable petroleum-based solvents include kerosene (mainly composed of C9-C15 hydrocarbons) and No. 5 industrial gasoline (cleaning solvent) used in dry cleaning. Petroleum-based solvents used in dry cleaning have a specific gravity of approximately 0.73-0.80 and are hydrocarbon mixtures. As halogenated hydrocarbon solvents, bromine-based solvents such as 1-bromopropane, which are used as dry cleaning solvents, chlorine-based solvents such as tetrachloroethylene (perchloroethylene) and trichloroethylene, and fluorine-based solvents such as 1,1,1,3,3-pentafluorobutane can be used. As for silicone-based solvents, decamethylcyclopentasiloxane and decamethyltetrasiloxane, which are used as dry cleaning solvents, can be used.

[0086] In the solvent treatment process (step S1), when the workpiece 110 is immersed in the solvent 120, the adhesive that was joining the constituent materials of the workpiece 110 dissolves in the solvent 120 and is removed from the workpiece 110. As a result, the joints of the constituent materials of the workpiece 110 peel off, causing dissociation and separation of the constituent materials of the workpiece 110. In other words, the workpiece 110 is decomposed as the bonds between the film, nonwoven fabric, or other sheet 20 that constitutes the absorbent article, which is the workpiece 110, are broken, and the workpiece 110 is separated into SAP 12, pulp fibers 11, sheet 20, etc. In particular, by chemically treating the workpiece 110 with the solvent 120, the nonwoven fabric or film sheet 20 peels off while generally maintaining its shape at the time of input, without being shredded. Then, the pulp fibers 11 and SAP 12 of the absorbent material 10, which were contained within the surface sheet 21 and the back sheet 22, are scattered into the solvent 120 as the bonds between the nonwoven fabric and film sheets 20 separate in the solvent 120.

[0087] Thus, in the solvent treatment step (step S1), the adhesive is removed from the workpiece 110 by immersing it in the solvent 120 and dissolving the adhesive in the solvent 120. In particular, in this chemical treatment where the adhesive is dissolved and removed by solvent 120, the material to be treated 110 is decomposed into its constituent materials. This treatment can reduce the bonding force between the sheets 20 and separate the constituent materials of the material to be treated 110 at room temperature, and since heating or crushing is not required to dismantle the material to be treated 110, it requires less energy and energy costs.

[0088] Next, in the separation and recovery step (step S2), the constituent materials of the workpiece 110 from which the adhesive has been dissolved and removed by immersion in the solvent 120 are separated and recovered. When the workpiece 110 is immersed in the solvent 120, the adhesive is dissolved and removed by the solvent 120, which breaks the bonds between the film, nonwoven fabric, or other sheet 20 of the workpiece 110. As a result, the workpiece 110 decomposes and dissociates, allowing the constituent materials of the workpiece 110 to be separated and recovered.

[0089] In this embodiment, the workpiece 110 is dismantled by dissolving the adhesive in the solvent 120 without finely crushing the workpiece 110. As a result, the nonwoven fabric or film sheet 20 is peeled and separated without being fragmented, and the pulp fibers 11 and SAP 12 of the absorbent body 10, which were embedded between the surface sheet 21 and back sheet 22 made of the nonwoven fabric or film, are scattered into the solvent 120 and can be easily separated from the sheet 20.

[0090] In particular, by removing the adhesive from the material to be treated 110, the pulp fibers 11 and SAP 12 of the absorbent 10 are less likely to adhere to and remain on the sheet 20 made of nonwoven fabric or film, and the pulp fibers 11 and SAP 12 of the absorbent 10 are separated from the nonwoven fabric or film sheet 20 cleanly and easily, and dispersed into the solvent 120. Furthermore, since the sheet 20 made of nonwoven fabric or film is separated while maintaining large dimensions without being fragmented, it is less likely that the sheet 20 will be mixed with the pulp fibers 11, etc. Furthermore, the nonwoven fabric or film sheet 20 and the pulp fibers 11 and SAP 12 of the absorbent material 10 differ significantly in size, making separation easy.

[0091] Here, the pulp fibers 11 and SAP 12 of the absorbent body 10 constituting the material to be processed 110, and the sheet 20 made of nonwoven fabric or film, can be separated and recovered by utilizing their dimensional differences, specific gravity differences (density differences), sedimentation / buoyancy differences, resistance, etc. As a separation and recovery means for separating and recovering the pulp fibers 11 and SAP 12 of the absorbent body 10 from the sheet 20 made of nonwoven fabric or film, for example, a screen, sieve, filter, etc. (hereinafter collectively referred to as "screen F1") having multiple holes that allow the pulp fibers 11 and SAP 12 of the absorbent body 10 to pass through, but not the sheet 20 made of nonwoven fabric or film can be used. For example, a screen with a mesh opening of 3 to 50 mm, preferably 5 to 40 mm, and more preferably 5 to 25 mm can be used. In this case, separation may be promoted by vibrating the screen F1, and a roller screen may also be used. Furthermore, the screen F1 may be arranged in multiple stages or cascaded. In this type of filtration separation using screen F1, the sheet 20 of nonwoven fabric or film is not broken, and the original shape is largely maintained. Furthermore, the pulp fibers 11 and SAP 12 of the absorbent 10 are not pulverized. In other words, the small-sized fine fragments P, such as the pulp fibers 11 and SAP 12 of the absorbent 10, and the larger-sized coarse fragments L, such as the sheet 20 made of nonwoven fabric or film, can be separated without putting any load on the constituent materials.

[0092] For example, by passing the treatment solution (solid-liquid mixture) obtained by immersing the material to be treated 110 in solvent 120 through the screen F1 described above, the pulp fibers 11 and fine fragments P such as SAP 12 of the absorbent 10 and the treatment solution (solvent 120) pass through the screen F1, while coarse fragments L such as nonwoven fabric or film sheets 20 are captured and recovered on the screen F1. In this way, the coarse fragments L such as sheets 20 can be separated from the pulp fibers 11 and fine fragments P such as SAP 12 of the absorbent 10 and recovered separately without being finely broken.

[0093] Alternatively, as shown in Figure 6, a rotatable drum R (drum screen) is installed in the treatment tank as a solvent treatment section 510, with a screen F1 on its outer circumference. The material to be treated 110 is then immersed in a solvent 120 within the drum R. Rotating the drum R during this process promotes the penetration of the solvent 120 into the material to be treated 110 and the dissolution of the adhesive into the solvent 120 due to the agitation, centrifugal force, and other physical impacts and external forces. The dissolution of the adhesive into the solvent 120 also facilitates the dissociation and separation of the constituent materials. Due to the centrifugal force of rotation, fine fragments P such as pulp fibers 11 and SAP 12 of the absorbent 10 are discharged from the holes in the screen F1 around the drum R to the outer casing outside the rotating drum R. Coarse fragments L such as nonwoven fabric or film sheets 20 remain inside, allowing the sheets 20 to be separated from the fine fragments P such as pulp fibers 11 and SAP 12 of the absorbent 10 without being finely torn, and recovered separately.

[0094] Alternatively, as shown in Figure 3, by installing a screen F1 in a treatment tank in which the workpiece 110 is immersed in a solvent 120, the gravitational force of the decomposed constituent materials of the workpiece 110 settling or floating in the solvent 120 due to the dissolution of the adhesive in the solvent 120 can be used to separate and recover coarse pieces L such as the sheet 20 and fine pieces P such as the pulp fibers 11 and SAP 12 of the absorbent body 10.

[0095] For example, if a solvent 120 with a specific gravity lower than that of the SAP 12 of the absorbent 10, preferably a petroleum-based, halogenated hydrocarbon-based, or mixture thereof dry cleaning solvent with a specific gravity of 0.7 or higher and 1.5 or lower, is used, when the adhesive bonds in the workpiece 110 are broken by immersion of the workpiece 110 in the solvent 120, the SAP 12 will settle (fall) in the solvent 120 in the treatment tank because its specific gravity is higher than that of the solvent 120 and it does not absorb the solvent 120. Also, the pulp fibers 11 will disperse or settle in the solvent 120 because the fibers are entangled with each other and their specific gravity is higher than that of the solvent 120.

[0096] Therefore, as shown in Figures 3 and 4, the screen F1 is installed at a predetermined position below the liquid level of the solvent 120 in the processing tank of the solvent processing unit 510 where the workpiece 110 is immersed in the solvent 120, but above the bottom. When the workpiece 110 is placed above the screen F1, the solvent 120 penetrates the workpiece 110 and the adhesive bonds are broken, causing the sheet 20, pulp fibers 11, SAP 12, etc. of the workpiece 110 to scatter in the solvent 120. Fine fragments P such as the pulp fibers 11 and SAP 12 of the absorbent 10 pass through the screen F1 and settle, but coarse fragments L such as the sheet 20 of the nonwoven fabric or film do not pass through the screen F1. Thus, the fine fragments P such as the pulp fibers 11 and SAP 12 of the absorbent 10 and the coarse fragments L such as the sheet 20 are separated above and below the screen F1. This allows for the separation and separate recovery of coarse pieces L such as the sheet 20 and fine pieces P such as the pulp fibers 11 and SAP 12 of the absorbent 10 without finely tearing the sheet 20. Preferably, by stirring at least the area above the screen F1 or vibrating the screen F1, the constituent materials of the material to be processed 110 become easier to dissociate and separate, and clogging due to the accumulation of sheet 20 on the screen F1 can be prevented, allowing for efficient separation of fine pieces P such as the pulp fibers 11 and SAP 12 of the absorbent 10 and coarse pieces L such as the sheet 20.

[0097] Specifically, the material to be treated 110 is introduced into the treatment tank of the solvent treatment unit 510 equipped with a screen F1 from above the screen F1, and a solvent 120 having a specific gravity lower than the specific gravity of the pulp fibers 11 and SAP 12 of the absorbent body 10 is poured from the solvent tank T1 connected to the solvent treatment unit 510 so that the liquid level is above the screen F1, thereby immersing the material to be treated 110 in the solvent 120. At this time, preferably, the solvent 120 is stirred and vibrated by a stirring means that immerses the material in the solvent 120, or by the rocking of the treatment tank, etc. When the object to be treated 110 is immersed in the solvent 120, the adhesive in the object to be treated 110 dissolves in the solvent 120, and as the adhesive is dissolved and removed from the object to be treated 110, the object to be treated 110 decomposes in the solvent 120, and its constituent materials become scattered. Furthermore, among the constituent materials of the material to be processed 110, fine fragments P such as the pulp fibers 11 and SAP 12 of the absorbent 10, which have a specific gravity greater than the solvent 120 and are smaller than the dimensions of the sheet 20, pass through the screen F1 and settle, while coarse fragments L such as the sheet 20, which are larger in dimensions than the pulp fibers 11 and SAP 12 of the absorbent 10, remain above the screen F1. Thus, the large coarse fragments L such as the sheet 20 and the fine fragments P such as the pulp fibers 11 and SAP 12 of the absorbent 10 can be recovered separately.

[0098] In this method, where the workpiece 110 is immersed in a solvent 120 in a solvent treatment unit 510, and the fine fragments P of the absorbent body 10, such as pulp fibers 11 and SAP 12, and the coarse fragments L of the sheet 20 are separated and recovered by sedimentation or flotation of the screen F1 and the constituent materials of the workpiece 110 in the solvent 120, clogging caused by the accumulation of coarse fragments L of the sheet 20 on the screen F1 is prevented, resulting in more efficient separation than when the treatment liquid obtained by immersing the workpiece 110 in the solvent 120 is passed through (flowed) through the screen F1. Furthermore, physical impact on the constituent materials is reduced, meaning that separation can be performed under gentle conditions, allowing for separation while maintaining higher quality without degrading the absorbent body 10 of pulp fibers 11 and SAP 12. Moreover, the apparatus can be made simpler in configuration, thus reducing costs.

[0099] Furthermore, coarse pieces L such as the sheet 20 that remain above the screen F1 can be recovered by, for example, scraping, scooping up, or winding them up from the solvent 120 with a sheet recovery means and discharging them outside the solvent treatment unit 510; they can be captured and recovered on the screen F1; or they can be discharged from the solvent treatment unit 510 together with the solvent 120 and separated and recovered from the solvent 120 using another screen or the like.

[0100] The pulp fibers 11 and fine fragments P of SAP 12 of the absorbent body 10 that have passed through screen F1 and settled in the processing tank of the solvent processing unit 510 may be further separated into pulp fibers 11 and SAP 12 by screen F2 in the solvent 120 of the solvent processing unit 510 by screen F2, by placing screen F2 below screen F1, which allows SAP 12 to pass through but not pulp fibers 11. Alternatively, the materials may be discharged from the solvent processing unit 510 together with the solvent 120, and screen F2 may be placed in a separate location (such as the absorbent body separation unit 520 described later) to separate the pulp fibers 11 and SAP 12 there.

[0101] In other words, the pulp fibers 11 and fine fragments P such as SAP 11 of the absorbent 10, which have been separated from the coarse fragments L such as the sheet 20, can be separated into pulp fibers 11 and SAP 12 by utilizing differences in dimensions, specific gravity (density), sedimentation / buoyancy, resistance, etc. As an absorbent body separation and recovery means for separating and recovering the pulp fibers 11 and SAP 12 of the absorbent body 10, for example, a screen, sieve, filter, etc. (hereinafter collectively referred to as "screen F2") having multiple holes such as round holes or openings such as slits that allow SAP 12 to pass through but not the pulp fibers 11 can be used. For example, a screen with a mesh size of 0.1 to 5 mm, preferably 0.15 to 3 mm, can be used. In this case, separation may be promoted by vibrating the screen F2, and a roller screen may also be used. Furthermore, the screen F2 may be arranged in multiple stages or cascaded.

[0102] For example, the processing liquid containing the pulp fibers 11 of the absorbent 10 and fine fragments P such as SAP 12, and the solvent 120, which have been separated from the coarse fragments L such as the sheet 20 by passing through the coarse screen F1 described above, or the processing liquid containing the pulp fibers 11 of the absorbent 10 and fine fragments P such as SAP 12, and the solvent 120, which has been released from the coarse screen F1 on the outer circumference of the rotating drum, can be further passed through a fine screen F2 that does not allow the pulp fibers 11 to pass through. In this way, the pulp fibers 11 are captured by the fine screen F2, while the SAP 12 and the solvent 120 of the processing liquid pass through the fine screen F2, so that the pulp fibers 11 can be separated and recovered separately from the SAP 12 by the fine screen F2.

[0103] The processing solution containing SAP12 and solvent 120 that has passed through the fine-mesh screen F2 is then passed through a fine-mesh screen that allows the solvent 120 to pass through but not the SAP12. As a result, the SAP12 is captured by the fine-mesh screen, while the solvent 120 passes through the fine-mesh screen. Therefore, the SAP12 can be separated from the solvent 120 by the fine-mesh screen and recovered separately.

[0104] Alternatively, a coarse screen F1 that prevents the passage of a sheet 20 or the like is placed at a predetermined position above the bottom of the processing tank of the solvent processing unit 510 in which the material to be processed 110 is immersed in the solvent 120, and a fine screen F2 that allows the SAP 12 to pass through but not the pulp fibers 11 is placed below that, and a fine screen that captures the SAP 12 is placed even lower, thereby enabling separation and recovery using sedimentation separation in the processing liquid. In other words, of the pulp fibers 11 and SAP 12 of the absorbent body 10 that have sunk after passing through the coarse screen F1 placed in the processing tank in which the material to be processed 110 is immersed in the solvent 120, the pulp fibers 11 remain below the coarse screen F1 and above the fine screen F2, while the SAP 12 passes through the fine screen F2 and sinks, and is captured by the fine screen even lower, thereby enabling the pulp fibers 11 and SAP 12 to be separated and recovered separately. Alternatively, the SAP12 may be deposited at the bottom of the processing tank and collected all at once.

[0105] Alternatively, as shown in Figures 3 and 5, the pulp fibers 11 and fine fragments P such as SAP 12 of the absorbent 10 that have passed through a coarse screen F1, which prevents the passage of a sheet 20 or the like, installed at a predetermined position above the bottom of the processing tank in the solvent processing unit 510 where the workpiece 110 is immersed in solvent 120, can be recovered and dried. In the absorbent separation unit 520, which is equipped with a fine screen F2 that allows SAP 12 to pass through but not pulp fibers 11, an absorbent separation solvent 220 different from the solvent 120 used to immerse the workpiece 110 in the solvent processing unit 510 can be placed in the processing tank, and the pulp fibers 11 and fine fragments P such as SAP 12 of the absorbent 10 can be placed in the absorbent separation solvent 220, and the pulp fibers 11 and SAP 12 can be separated and recovered separately in the absorbent separation solvent 220. The absorbent separation solvent 220 can be the same as those listed for solvent 120 above.

[0106] In particular, when the pulp fibers 11 and SAP 12 of the absorbent body 10 are immersed in a solvent 220 having a specific gravity greater than that of the pulp fibers 11 and SAP 12 of the absorbent body 10, preferably a halogenated hydrocarbon-based dry cleaning solvent or a mixed solvent of the halogenated hydrocarbon-based dry cleaning solvent and a petroleum-based dry cleaning solvent having a specific gravity in the range of 1.6 or more and 1.8 or less, the SAP 12 will float in the solvent 220 of the treatment tank because its specific gravity is lower than that of the solvent 220 and the pulp fibers 11, and therefore it will not absorb the solvent 220.

[0107] Therefore, as shown in Figures 3 and 5, the above-mentioned screen F2 is installed at a predetermined position in the processing tank of the absorbent separation unit 520 containing the absorbent separation solvent 220, and the pulp fibers 11 and fine pieces P such as SAP 12 of the absorbent 10, which have been separated, recovered, and dried separately from the coarse pieces L such as the sheet 20, are supplied to a position below the screen F2. As a result, the granular material P2 such as SAP 12 floats up, passes through the screen F2, and moves to a position above the screen F2, while the fibrous material P1 such as pulp fibers 11 does not pass through the screen F2 and remains below the screen F2. Thus, the granular material P2 such as SAP 12 and the fibrous material P1 such as pulp fibers 11 are separated above and below the screen F2.

[0108] Specifically, the absorbent separation solvent 220, which has a higher specific gravity than the pulp fibers 11 and SAP 12, is injected from a solvent tank T2 connected to the absorbent separation unit 520 and containing the absorbent separation solvent 220 into the treatment tank of the absorbent separation unit 520. Fine fragments P of the absorbent 10, such as pulp fibers 11 and SAP 12, which have been separated, recovered, and dried separately from coarse fragments L such as the sheet 20 below the screen F2 in the treatment tank of the absorbent separation unit 520 equipped with a screen F2, are then supplied. Preferably, the absorbent separation solvent 220 is stirred and vibrated by an agitator immersed in the absorbent separation solvent 220, or by the oscillating of the treatment tank. When fine fragments P such as pulp fibers 11 and SAP 12 of the absorbent body 10 are introduced into the absorbent body separation solvent 220 and stirred, the SAP 12, which is lighter in specific gravity than the absorbent body separation solvent 220 and pulp fibers 11, is granular and smaller in size, rises (floats) in the absorbent body separation solvent 220, passes through the screen F2 and moves to the area above the screen F2, while the pulp fibers 11, which are larger in size than the SAP 12 due to the entanglement of single fibers, remain below the screen F2. Therefore, granular material P2 such as SAP 12 and fibrous material P1 such as pulp fibers 11 can be recovered separately.

[0109] The granular material P2, such as SAP12, that floats above screen F2 can be discharged outside the absorbent separation unit 520 along with the solvent 220 and separated and recovered from the solvent 220 using another screen, or it can be captured and recovered on screen F2. Fibrous material P1 such as pulp fibers 11 that remains below screen F2 is discharged to the outside of the absorbent separation section 520 together with the solvent 220 and recovered. Alternatively, it can be separated and recovered from the solvent 220 using another screen, or it may be recovered by accumulating at the bottom of the treatment tank when SAP 12 and solvent 220 are discharged.

[0110] In this method, where the absorbent body separation unit 520 separates and recovers granular material P2 such as SAP12 and fibrous material P1 such as pulp fibers 11 from fine fragments P such as SAP12 of the absorbent body 10 in an absorbent body separation solvent 220 using a screen F2 and a separation and recovery means for floating SAP12, the separation is more efficient than when the processing liquid of the solvent 120 containing granular material P2 such as SAP12 and fibrous material P1 such as pulp fibers 11 is passed through (flowed) through the screen F2. This prevents clogging caused by the accumulation of fibrous material P1 on the screen F2, and allows for more efficient separation. Furthermore, it reduces physical impact on the constituent materials, meaning that separation can be performed under gentle conditions. This allows for separation while maintaining higher quality without degrading the absorbent body 10 of pulp fibers 11 and SAP12. Moreover, the apparatus can be made simpler, resulting in lower costs.

[0111] In other words, by separating pulp fibers 11 and SAP 12 using gravity in an absorbent separation solvent 220 with a higher specific gravity than screen F2 and SAP 12, it is possible to separate and recover SAP 12 and pulp fibers 11 with extremely low mixing ratio and high purity, with low energy and minimal load on the pulp fibers 11 and SAP 12. Pulp fibers 11 and SAP 12 can be separated with high separation accuracy, and high-purity pulp fibers 11 and SAP 12 can be obtained with good productivity. Therefore, the pulp fibers 11 and SAP 12 can be separated with high precision with a low energy load without causing pulverization or pulverization of the pulp fibers 11 and SAP 12, and the separated and recovered pulp fibers 11 and SAP 12 are of high quality with little degradation. Therefore, it is suitable for material recycling. In particular, even when the material to be processed 110 is immersed in the solvent 120, SAP 12 does not absorb oil, and as described above, it can be separated and recovered without pulverization or pulverization, so the particle size distribution does not change significantly, and it can be recovered with a high recovery rate while maintaining the original properties such as water absorption, so the recovered SAP 12 is of high quality and suitable for material recycling as a constituent material of absorbent articles. Furthermore, in the case of pulp fibers 11, since the material to be processed 110 is not finely crushed, there is less contamination with sheets 20, elastic threads 25, tapes, etc., and separation and recovery can be performed with low load without degrading the material, so that it can be recovered at a high recovery rate while maintaining the original properties such as water absorption, and the recovered pulp fibers 11 are of high quality and suitable for material recycling as a constituent material of absorbent articles.

[0112] In carrying out the present invention, as a separation and recovery step for separating and recovering the pulp fibers 11 and SAP 12, for example, in a processing liquid containing solvent 120 after the recovery of coarse pieces L such as sheets 20, a liquid flow is applied to the pulp fibers 11 and SAP 12, and the SAP 12, which has a relatively lower specific gravity, is moved by the liquid flow to a different location from the pulp fibers 11, which has a relatively higher specific gravity, thereby separating them. Alternatively, separation and recovery can be performed using a wet classifier such as a liquid cyclone HC that utilizes centrifugal force.

[0113] As shown in Figure 6, the liquid cyclone HC is formed in a conical (inverted triangular pyramidal) cylindrical shape. An inlet is provided on the upper side of the cone (cylindrical container) through which the processing liquid is pumped from the side. A lower outlet is located at the lower end of the cone, and an upper outlet is located at the upper end of the cone. By pumping the processing liquid containing the pulp fibers 11 and SAP 12 of the absorber 10 and the solvent 120 into the inlet of the liquid cyclone's cone, the centrifugal force from the vortex of rotational motion causes the processing liquid to swirl at high speed along the inner wall of the cylinder in the circumferential direction. The pulp fibers 11 are discharged from the upper outlet along with the solvent 120 of the processing liquid, and the SAP 12 descends while swirling along the inner wall and is discharged from the lower outlet. This also allows the SAP 12 to be separated and recovered separately from the processing liquid containing the pulp fibers 11 and the solvent 120. Furthermore, the pulp fibers 11 and the solvent 120 can be separated and recovered separately by screen or sedimentation separation. In a method that separates pulp fibers 11 and SAP 12 contained in a solvent 120 into which the workpiece 110 is immersed, using centrifugal force, the medium is the processing liquid of the solvent 120. Therefore, it is possible to separate pulp fibers 11 and SAP 12 with a small number of steps, with high production efficiency and higher precision.

[0114] Furthermore, the coarse fragments L, including the separated and collected sheets 20, may be further separated from other constituent materials such as the elastic thread 25 and tape before being subjected to the drying process (step S3), or they may be separated after the drying process (step S3). In addition, the sheets 20, which are made of nonwoven fabric or film, can be further separated into multiple types using differences in specific gravity, etc. The specific gravity of the sheets 20 will vary depending on the type and content of the resin and fillers (additives). Furthermore, the granular material P2 containing SAP12 and other materials, and the fibrous material P1 containing pulp fibers 11 and other materials, may be subjected to the drying process (step S3) described later after the other constituent materials such as the elastic thread 25 and tape have been separated and removed, or they may be separated and removed after the drying process (step S3). The separated elastic thread 25 and other constituent materials such as tape can also be recycled as material.

[0115] In particular, in this embodiment, since the material to be processed 110 is not finely crushed, the recovered SAP 12 and pulp fibers 11 contain fewer fine sheets 20, elastic threads 25, tapes, etc., making foreign matter separation easy and allowing for the high-purity separation and recovery of SAP 12 and pulp fibers 11. Furthermore, since the adhesive of the material to be processed 110 is dissolved in the solvent 120 to decompose and dismantle the material, and the constituent materials are separated and recovered, the nonwoven fabric and film sheets 20 are not fragmented but are dissociated while generally maintaining their shape at the time of input. Moreover, since the adhesive is removed from the material to be processed 110, the absorbent material 10 of the pulp fibers 11 and SAP 12 is less likely to adhere to and remain on the nonwoven fabric and film sheets 20, making foreign matter removal easy. Furthermore, since the adhesive is removed, the sheets 20 can be recovered with less foreign matter and in high quality, making the recovered sheets 20 suitable for recycling in a wide range of applications. Since SAP12 and other substances are granulated and powdered, preventing them from flowing out, there is no burden on wastewater.

[0116] Thus, in this embodiment, the material to be processed 110 is dismantled by removing the adhesive from the material to be processed 110 without finely defibrating, crushing, or pulverizing it. Therefore, the sheets 20, such as the surface sheet 21 and back sheet 22 made of nonwoven fabric or film, and the absorbent body 10, which consists of pulp fibers 11 and SAP 12 embedded between the surface sheet 21 and back sheet 22, are easily separated. As a result, they can be separated accurately with little energy, i.e., under low-load conditions, without having to input excessive energy that would cause the SAP 12 to become finely granulated or pulverized. Furthermore, since the SAP 12 and pulp fibers 11 can be separated and recovered without causing deterioration due to fine granulation or pulverization, or changes in properties such as water absorption, they are suitable for recycling as constituent materials for absorbent articles. In other words, by immersing the workpiece 110 in solvent 120 to dissolve the adhesive and dismantle the workpiece 110, the adhesive of the workpiece 110 is removed, causing the sheet 20 to separate while maintaining its large dimensions without being fragmented. This eliminates the entanglement and adhesion of the constituent materials of the workpiece 110 that would occur if it were finely defibrated, crushed, or pulverized, and the constituent materials of the workpiece 110 can be easily scattered. As a result, the constituent materials can be separated and recovered with less energy, and the recovery rate of the constituent materials is also high.

[0117] Thus, in the separation and recovery process (step S2), at least the pulp fibers 11, the SAP 12, and the sheet 20 such as nonwoven fabric or film are separately separated and recovered from the constituent materials of the treated material 110 from which the adhesive has been removed, using separation and recovery means such as screens F1 and F2.

[0118] Next, in the drying process (step S3), in the drying section 550 equipped with drying means, each of the separated and recovered constituent materials is dried by the drying means, thereby removing any remaining solvents 120 and 220 from each of the separated and recovered constituent materials. As for drying methods, for example, solvents 120 and 220 can be volatilized by natural drying at room temperature, drying at a temperature higher than room temperature, air drying with ambient air, drying by blowing hot air, or reduced pressure drying, and heaters, vacuum pumps, fans, etc., can be used. However, in the case of petroleum-based solvents 120 and 220, due to their low flash points, the solvents 120 and 220 should be volatilized under reduced pressure, with nitrogen purging and controlled gas and oxygen concentrations. It is preferable to dry the solvent until the solvent content is 1% by mass or less. The drying process at this stage can be carried out by drying each recovered component material individually or by drying them together. Since the drying is performed using solvents 120 and 220, it can be done with low load and energy saving. In the drying section 550, the drying time can be shortened by preventing uneven drying and promoting solvent removal through a mechanism that rotates the processing tank, such as a mechanism that rotates the tank itself or a mechanism that rotates a rotating body installed inside the tank, or by using airflow.

[0119] Furthermore, the coarse fragments L, including the sheets 20, which have been separated and dried, may be further separated and collected into sheets 20 such as nonwoven fabric or film, and other constituent materials such as elastic thread 25 and tape. The sheet 20, which consists of nonwoven fabric or film, can be further separated into multiple types using differences in specific gravity, etc. The specific gravity of the sheet 20 varies depending on the type and content of the resin and fillers (additives). Furthermore, SAP12 is recovered after the granular material P2 containing the separated and dried SAP12 has been separated and removed from the elastic thread 25, tape, and other constituent materials. In other words, SAP12 is recovered by separating and removing the elastic thread 25, tape, and other constituent materials from the granular material P2 containing the separated and dried SAP12. The pulp fibers 11 are recovered after they have been separated and dried, and other constituent materials such as the elastic thread 25 and tape have been separated and removed from the fibrous material P1 containing the pulp fibers 11. In other words, the pulp fibers 11 are recovered by separating and removing the elastic thread 25 and tape from the fibrous material P1 containing the pulp fibers 11 that have been separated and dried. The separated elastic threads 25, tapes, and other constituent materials can also be recycled as material resources.

[0120] Thus, in this embodiment, in the solvent treatment unit 510, a solvent treatment step (step S1) is performed in which an unused absorbent article to be treated 110, which is an absorbent article consisting of an absorbent body 10 containing pulp fibers 11 and SAP 12, is surrounded by a sheet 20 such as a film or nonwoven fabric and the opposing sheets 20 are joined together with an adhesive, is immersed in a solvent 120 to dissolve the adhesive of the article to be treated 110 in the solvent 120. A separation and recovery step (step S2) is performed in which the constituent materials of the article to be treated 110 from which the adhesive has been dissolved and removed are separated and recovered by a separation and recovery means. A drying step (step S3) is performed in which the separated and recovered constituent materials are dried by a drying means. In this way, at least the pulp fibers 11, SAP 12, and the sheet 20 such as a nonwoven fabric or film are separated and recovered from the unused absorbent article to be treated 110.

[0121] Thus, in this embodiment, the material to be processed 110 is disassembled and broken down by dissolving the adhesive in the solvent 120 without finely crushing the material to be processed 110, thereby separating and recovering the constituent materials. As a result, the nonwoven fabric or film sheets 20 are separated while largely maintaining their original shape without being fragmented (decomposed), and the adhesive is removed from the material to be processed 110. This makes it difficult for the pulp fibers 11 and SAP 12 absorbent material 10 to adhere to and remain on the nonwoven fabric or film sheets 20, and makes it easy to separate the nonwoven fabric or film sheets 20 from the pulp fibers 11 and SAP 12 absorbent material 10 that were embedded between the surface sheet 21 and the back sheet 22. Therefore, constituent materials can be separated efficiently and accurately with less energy and energy cost, and the recovery rate is also high. Furthermore, since the constituent materials can be easily separated without applying excessive energy, the pulp fibers 11 and SAP 12 of the absorbent 10 can be separated with less load, suppressing the miniaturization and degradation of the pulp fibers 11 and SAP 12. Moreover, the adhesive has been removed from the separated pulp fibers 11 and SAP 12. Therefore, the recovered pulp fibers 11 and SAP 12 are of high quality, suitable for material recycling, and have properties that are not inferior to virgin raw materials. Consequently, they can be reused as constituent materials for absorbent articles, enabling material recycling for a wide range of applications. In particular, in this embodiment, the material to be treated 110 is immersed in solvent 120 and the constituent materials are separated and recovered in a wet state, so separation can be performed accurately with low energy load, and SAP 12 and pulp fibers 11 are less likely to be pulverized or micronized, resulting in a high-quality product.

[0122] Therefore, the recovered SAP12 can be reused in absorbent materials, and can also be used in a wide range of applications, including agriculture and horticulture (soil water retention agent, pesticide disintegration aid, etc.), food (freshness preservative, antifreeze, coolant), civil engineering and construction (solidifying agent, anti-condensation agent, waterproofing material), cosmetics and pharmaceuticals (fragrances, cosmetics, patches), hygiene products, emergency toilets, electrical and electronic materials (waterproofing material for optical cables), and paints. Pulp fibers 11 can, of course, be reused in absorbent materials, and can also be used for material recycling in a wide range of applications as fiber materials for paper, cardboard, sanitary products, etc. Chemical recycling is also possible through saccharification treatment, etc.

[0123] Furthermore, in this embodiment, the sheets 20 that constitute the material to be treated 110 can also be easily separated from the pulp fibers 11 and SAP 12 of the absorbent body 10 while maintaining approximately the original sheet shape of the sheets 20, such as the surface sheet 21 and the back sheet 22, by solvent treatment in which the adhesive is dissolved by immersion in the solvent 120 without crushing the material to be treated 110, and can be recovered with a high recovery rate.

[0124] Coarse fragments L, such as sheets 20, separated and recovered from the material to be processed 110 can be solidified by compression or other means and thermally recycled as solid fuel (Refuse derived paper and plastics densified fuel: RPF). In particular, coarse fragments L, such as sheets 20, separated and recovered from unused absorbent materials 110, have had the adhesive removed and contain little impurities such as moisture, ash, and chlorine, resulting in good ignition properties, a high calorific value, and stable, high-quality solid fuel. That is, it can be produced as a high-quality solid fuel that has a high calorific value comparable to coal and coke, and is less likely to cause boiler corrosion due to chlorine gas or the generation of dioxins. In other words, the unused absorbent material 110 is immersed in solvent 120 to dissolve the adhesive, thereby dismantling the material 110. In the sheet 20 obtained by separating the SAP 12 and pulp fibers 11 by filtration separation using a screen F, the SAP 12 and pulp fibers 11 are not finely granulated or pulverized, resulting in a sheet with extremely low contamination of SAP 12 and pulp fibers 11, and furthermore, there is no adhesive residue, resulting in a high-quality product. Therefore, the solid fuel obtained by molding and compressing these materials in a molding machine and then cooling them in a cooling machine results in a solid fuel with a low moisture content due to the extremely low proportion of SAP 12 and pulp fibers 11. Moreover, the SAP 12 is not inactivated with an inactivating agent such as calcium chloride, and furthermore, because the adhesive has been removed, the content of impurities such as ash and chlorine is also low. Therefore, it has a high calorific value and is of high quality. Furthermore, in the solid fuel obtained by solidifying the sheet 20 separated from the SAP 12 and pulp fibers 11, the SAP 12 does not expand due to water absorption, resulting in a lightweight fuel that requires less space and energy for storage and transportation, and reduces the burden on workers during transportation, allowing for safer work. In addition, because the proportion of SAP 12 is extremely low, there is no risk of off-odors due to the heat accumulation of SAP 12 or of ignition.

[0125] Alternatively, the material can be melted and solidified (pelletized) to become a plastic raw material and recycled into plastic products. In particular, the coarse pieces L such as sheets 20 separated and recovered from the unused absorbent material 110 are easy to use in plastic processing because the adhesive has been removed, resulting in fewer impurities. That is, in this embodiment, since the adhesive has been removed from the separated sheets 20 such as film and nonwoven fabric, even when they are melted as a plastic raw material and stretched into a film, or molded into resin by extrusion molding, blow molding, etc., they have properties that are not inferior to virgin raw materials, resulting in a high-quality, high-purity recycled material product. In this case, the coarse pieces L, such as the sheet 20 consisting of multiple types of nonwoven fabrics and films, will be further separated and sorted by component using differences in specific gravity, etc. As a means of separating the nonwoven fabric and film sheets 20, a cyclone or the like can be used to centrifuge the material in the solvent 120 before drying or in the air after drying, and it is also possible to separate the film sheets and nonwoven fabric sheets using a cyclone or the like that utilizing centrifugal force. The various plastic raw materials with different specific gravities that have been separated in this way can be materially recycled into resin products such as absorbent articles, packaging materials (bags, films, containers, tubes, wraps, etc.), plastic films, and plastic bags.

[0126] Alternatively, it can be converted into oil and recycled chemically or thermally as a product oil such as naphtha, diesel fuel, or heavy oil, or as a blast furnace reducing agent or coke substitute. The resulting oil can be used as a fuel, a chemical raw material for plastics, and other applications.

[0127] Furthermore, this embodiment includes an adhesive separation and recovery step (step S4) in which the solvent 120 in which the adhesive is dissolved after the constituent materials of the workpiece 110 have been recovered is distilled, and the adhesive precipitated by distillation is separated and recovered. In the adhesive separation and recovery step (step S4), the adhesive is precipitated and separated from the solvent 120 in which the adhesive remains after the constituent materials of the workpiece 110 have been recovered by distillation, which is the adhesive separation and recovery means. Furthermore, in the separation and recovery apparatus of this embodiment, a solvent circulation path 540 is formed connecting the solvent tank T1 and the distillation section 530. The solvent 120 from which the adhesive has been removed by cooling the solvent gas in the distillation section 530 is supplied to the solvent tank T1 through the solvent circulation path 540 and reused as the solvent 120 for immersion treatment of the workpiece 110. The solvent circulation path 540 is equipped with a filtration section with a filter, and after foreign matter is removed from the solvent 120 from which the adhesive has been removed by the filter in the filtration section, it is reused again as the solvent 120 for immersion treatment of the workpiece 110.

[0128] In other words, the solid adhesive can be separated and recovered from the solvent 120 by distilling the solvent 120 in which the adhesive is dissolved and precipitating the adhesive. The evaporated solvent gas then condenses upon cooling, becoming liquid solvent 120 from which the adhesive has been removed. This liquid solvent is then filtered through the filtration section and reused as the solvent 120 into which the workpiece 110 is immersed. In particular, petroleum-based and halogenated hydrocarbon-based dry cleaning solvents 120 offer a high recovery rate for dissolved adhesives.

[0129] Thus, in this embodiment, the solvent 120 in which the adhesive is dissolved is not discarded externally, but the adhesive is recovered by distillation and used repeatedly as the solvent 120 for immersion treatment of the workpiece 110. Therefore, the cost can be reduced without the need for waste liquid treatment of the solvent 120. Furthermore, since the adhesive can be separated and recovered by distillation of the solvent 120 in which the adhesive is dissolved, the adhesive can also be recycled as a material, making more effective use of the resources of the constituent materials of the absorbent article. In other words, in this embodiment, the object to be treated 110 is decomposed and dismantled by dissolving the adhesive in the object to be treated 110 in the solvent 120. Since the adhesive is dissolved in the solvent 120, it is possible to precipitate the adhesive from the solvent 120 by distillation, and thus it is possible to separate and recover the adhesive from the object to be treated 110, which is an unused absorbent article, and recycle the material. Therefore, it is possible to increase the reusability and recycling rate of the constituent materials of unused absorbent articles, and contribute to environmental protection.

[0130] Furthermore, the series of separation and recovery devices have an intake section for drawing in outside air and an exhaust section for discharging internal air. Outside air drawn in by the intake section is supplied by the operation of a fan, and internal air is appropriately treated and discharged to the outside from the exhaust section.

[0131] As described above, the method for separating and recovering the constituent materials of an absorbent article according to this embodiment is a method for separating and recovering the constituent materials from unused absorbent articles, such as off-spec products or scraps, which are made by surrounding an absorbent body 10 of pulp fibers 12 and superabsorbent polymer (SAP) 12 with sheets 20 and joining the opposing sheets 20 with a hot melt adhesive. The method involves a solvent treatment step (step S1) in which the object to be treated 110, which is an unused absorbent article such as an off-spec product or scrap, is immersed in a solvent 120 to dissolve the adhesive joining the sheets 20, a separation and recovery step (step S2) in which the constituent materials of the absorbent article that have been dissociated by the dissolution of the adhesive in the solvent 120 are separated and recovered, and a drying step (step S3) in which the separated and recovered constituent materials are dried to volatilize the solvent 120.

[0132] Furthermore, the separation and recovery device for the constituent materials of absorbent articles of this embodiment is a separation and recovery device for separating and recovering the constituent materials from unused absorbent articles, such as off-spec products or scraps, which are made by surrounding an absorbent body 10 of pulp fibers 12 and superabsorbent polymer (SAP) 12 with sheets 20 and joining the opposing sheets 20 with a hot melt adhesive. The device comprises a solvent treatment unit 510 that immerses the workpiece 110, which is an unused absorbent article such as an off-spec product or scrap, in a solvent 120 to dissolve the adhesive joining the sheets 20; a separation and recovery means such as a screen F1 that separates and recovers the constituent materials of the absorbent article that have been dissociated by the dissolution of the adhesive in the solvent 120; and a drying means such as a heater, a vacuum pump, or a fan that dries the separated and recovered constituent materials to volatilize the solvent 120.

[0133] According to this embodiment of the method and apparatus for separating and recovering the constituent materials of an absorbent article, the hot-melt adhesive joining the constituent members of an unused absorbent article is dissolved in solvent 120 to dissociate the constituent members, and the constituent materials are separated and recovered. As the adhesive is dissolved and removed, the dissociation and decomposition of the absorbent article (processed object 110) becomes easier, and the recovery rate of the constituent materials can be improved. In particular, by removing the adhesive, there is no entanglement caused by the adhesive, and the sheet 20 and the pulp fibers 11 and SAP 12 contained within it can be easily separated due to differences in size, specific gravity, etc., with less energy without fine-tuning or pulverizing the pulp fibers 11 and SAP 12 of the absorbent body 10. Furthermore, the pulp fibers 11 and SAP 12 of the absorbent body 10 can be separated accurately with less energy without fine-tuning or pulverizing them, and the adhesive is also removed, allowing for the separation and recovery of constituent materials such as the sheet 20, pulp fibers 11, and SAP 12 with high quality, making it suitable for material recycling.

[0134] In particular, in this embodiment, the constituent materials of the absorbent article from which the adhesive has been removed are immersed in solvent 120, and the constituent materials of the absorbent article are separated and recovered in the solvent 120 before being dried. Separating the constituent materials in a wet state using the difference in specific gravity with the solvent 120 and gravity allows for separation under low-stress conditions for the constituent materials. Therefore, by separating the constituent materials under gentle conditions that do not degrade or micronize them, the constituent materials can be separated and recovered with high quality.

[0135] Furthermore, in the sheet separation and recovery process, the constituent materials of the absorbent article from which the adhesive has been removed in the solvent treatment section 510 are immersed in the solvent 120, and in the solvent 120 they are separated into the sheet 20 and the pulp fibers 11 and SAP 12 as absorbent material 10. Then, in the absorbent material separation and recovery process, in the absorbent material separation section 520 the pulp fibers 11 and SAP 12 separated from the sheet 20 are separated into pulp fibers 11 and SAP 12 in a solvent 220 which has a specific gravity higher than SAP 12. This method allows for high-quality separation and recovery of the sheet 20, pulp fibers 11 and SAP 12 with high precision using a low load, soft conditions, and a simple equipment configuration, without pulverizing or finely grinding the pulp fibers 11 and SAP 12, and is also low-cost.

[0136] Furthermore, in this embodiment, as an adhesive separation and recovery step (step S4), the adhesive is precipitated and separated and recovered by distilling the solvent 120 in which the adhesive has dissolved in the distillation section 530, thereby enabling material recycling of the adhesive as well, and further effective utilization of resources. In addition, since the solvent 120 distilled by the solvent circulation path 540 is reused as the solvent 120 to be immersed in the absorbent material to be treated 110 in the solvent treatment section 510, the wastewater treatment of the solvent 120 is unnecessary, making it possible to reduce the environmental burden and lower costs.

[0137] Here, an example 1 of a separation and recovery method and separation and recovery apparatus for separating and recovering the constituent materials of unused absorbent articles in this embodiment will be described with reference to Figures 3 to 5. The separation and recovery apparatus according to this embodiment 1 is equipped with a screen F1 as a separation means in the processing tank of the solvent processing unit 510 in which the material to be processed 110 is immersed in the solvent 120. The screen F1 has multiple holes such as round holes or slits of a diameter that allows the SAP 12 of the absorbent body 10 and the pulp fibers 11 to pass through, but does not allow the sheet 20 to pass through, and the mesh opening is about 5 to 25 mm.

[0138] Furthermore, a solvent tank T1 containing solvent 120 is connected to the solvent processing unit 510 via a pump and valves. When the valve is open, the pump drives the solvent 120 from the solvent tank T1 into the processing tank of the solvent processing unit 510. When the pump is stopped or the valve is closed, the supply of solvent 120 from the solvent tank T1 into the processing tank is stopped. Thus, the solvent 120 into which the object to be processed 110 is immersed is pumped from the solvent tank T1 into the processing tank of the solvent processing unit 510 up to a predetermined liquid level.

[0139] First, the object to be treated 110 is placed in the treatment tank of the solvent treatment unit 510, a valve installed between the connection between the solvent treatment unit 510 and the solvent tank T1 is opened, and the pump is operated to introduce the solvent 120 in the solvent tank T1 into the treatment tank of the solvent treatment unit 510 to a predetermined liquid level above the screen F1, thereby immersing the object to be treated 110 in the solvent 120 within the treatment tank of the solvent treatment unit 510. As shown in Figure 4, when the object to be treated 110 is immersed in the solvent 120 in the processing tank of the solvent processing unit 510, the adhesive in the object to be treated 110 dissolves in the solvent 120, causing the object to decompose, dissociate, and break down, and the constituent materials of the object to be treated 110 to disperse into the solvent 120. At this time, preferably, the solvent 120 in which the object to be treated 110 is immersed is stirred with a stirring means such as a stirrer. Alternatively, the processing tank itself is oscillated to vibrate the solvent 120. This promotes the decomposition of the object to be treated 110 and the separation of its constituent materials, thereby improving processing efficiency.

[0140] In this embodiment 1, a petroleum-based dry cleaning solvent 120 with a specific gravity of 0.6 or more and 0.8 or less, which is lower than the specific gravity of the pulp fibers 11 and SAP 12 of the absorbent body 10, was used as the solvent 120. Then, in the processing tank of the solvent processing unit 510, the workpiece 110 was placed above the screen F1 installed in the processing tank of the solvent processing unit 510. As shown in Figure 4, in the processing tank of the solvent processing unit 510, the adhesive in the workpiece 110 dissolves in the solvent 120, causing the workpiece 110 to decompose, dissociate, and break down. Among the constituent materials of the workpiece 110, fine fragments P such as the cotton-like pulp fibers 11 and granular SAP 12 of the absorbent body 10 descend and pass through the screen F1, settling below the screen F1, while coarse fragments L such as the sheet 20 remain above the screen F1 without passing through it.

[0141] Thus, in this embodiment 1, a screen F1 is installed in the solvent treatment unit 510, and solvent 120 is filled to a level above the position of the screen F1. The workpiece 110 is then placed above the position of the screen F1 and immersed in petroleum-based dry cleaning solvent 120 with a specific gravity of 0.6 or more and 0.8 or less. Due to gravity caused by the difference in specific gravity between the solvent 120 and the workpiece 10, and because the fine fragments P such as pulp fibers 11 and SAP 12 of the absorbent body 10 are smaller in size than the pores of the screen F1, the fine fragments L such as the sheet 20 remain above the screen F1. As a result, the fine fragments P such as pulp fibers 11 and SAP 12 of the absorbent body 10 that have settled below the screen F1 are separated from the coarse fragments L such as the sheet 20 that remain above the screen F1. Therefore, the fine fragments P, such as the pulp fibers 11 and SAP 12, and the coarse fragments L, such as the sheet 20, can be recovered separately.

[0142] Coarse fragments L, such as sheets 20, that remain above screen F1 are recovered by being scraped, scooped up, or wound up from the solvent 120, or by utilizing airflow or liquid flow to discharge them outside the solvent treatment area 510. The coarse fragments L, such as sheets 20, discharged from the solvent treatment area 510 are transported to a drying area 550 equipped with drying means such as a heater, a pressure pump, and a fan, where they are dried with hot air or the like. The recovered and dried coarse fragments L, including sheets 20, are then thermally recycled, materially recycled, or chemically recycled as solid fuel, plastic raw material, or generated oil. Furthermore, since the dried coarse pieces L of the sheet 20 may contain other constituent materials such as elastic thread 25 and labels, the nonwoven fabric or film sheet 20 and the other constituent materials such as elastic thread 25 may be separated, collected separately, and recycled separately.

[0143] In the processing tank of the solvent processing unit 510, the fine fragments P such as pulp fibers 11 and SAP 12 that have settled below the screen F1 are discharged outside the processing tank of the solvent processing unit 510 together with the solvent 120, after the coarse fragments L such as sheets 20 have been discharged to the outside. After being filtered in the filtration unit 560 to remove the solvent 120, the material is sent to the drying unit 550, which is equipped with drying means such as a heater, a vacuum pump, and a fan. The solvent 120 containing pulp fibers 11 and fine fragments P such as SAP 12 discharged from the solvent treatment unit 510 is separated into the solvent 120 and the fine fragments P such as pulp fibers 11 and SAP 12 by filtration in the filtration unit 560. The fine fragments P such as pulp fibers 11 and SAP 12 separated from the solvent 120 in the filtration unit 560 are then fed to the drying unit 550, where they are dried by hot air drying, vacuum drying, etc., and desolvented. Note that in Figure 3, multiple drying sections 550 are shown for clarity, but this does not mean that the separation device has multiple drying sections 550; one or more drying sections 550 are sufficient. Also, when implementing the present invention, a filtration section 560 may be provided in the solvent treatment section 510. The filtration means in the filtration section 560 may be, for example, filter filtration or sedimentation separation.

[0144] In this embodiment 1, the filtration unit 560 is connected to the distillation unit 530, and the solvent 120 discharged from the filtration unit 560 is supplied to the distillation unit 530 where it is distilled. The solvent 120 discharged from the filtration section 560 may be recovered once in a solvent recovery tank located between the filtration section 560 and the distillation section 530, and then supplied to the distillation section 530 from there. The solvent gas exhaust from drying the pulp fibers 11 and fine pieces P such as SAP 12 in the drying section 550 may also be cooled and supplied to the solvent recovery tank and distillation section 530. Since the adhesive contained in the object to be treated 110 is dissolved in the solvent 120 into which the object to be treated 110 was immersed, the adhesive precipitates when the solvent 120 is distilled in the distillation section 530 after the object to be treated 110 has been immersed, and the adhesive is then separated and recovered.

[0145] Furthermore, in this embodiment 1, the distillation section 530 is connected to the solvent tank T1 by a solvent circulation path 540, and a filtration section equipped with a fine-mesh filter for removing foreign matter is provided in the middle of the solvent circulation path 540. From here, the solvent gas evaporated in the distillation section 530 is cooled and condensed to produce a liquid solvent 120. After fine foreign matter is filtered out by the filter in the filtration section, the solvent is sent to the solvent tank T1 and reused as solvent 120 for immersion treatment of the workpiece 110.

[0146] In this embodiment 1, the pulp fibers 11 and fine fragments P such as SAP 12 of the absorbent body 10 that have been dried in the drying section 550 are further transported to the absorbent body separation section 520 and put into the processing tank of the absorbent body separation section 520. As shown in Figure 5, the processing tank of the absorbent separation section 520 is equipped with a screen F2 as an absorbent separation and recovery means. The screen F2 has multiple holes such as round holes or slits of a diameter that allows the SAP 12 to pass through but does not allow the pulp fibers 11 to pass through, and the mesh opening is about 1 mm.

[0147] In this embodiment 1, the absorber separation unit 520 consists of a separation unit 520a on which a screen F2 is installed, and an input unit 520b which has an opening A that opens upward into which fine fragments P are fed, is connected to the separation unit 520a below the screen F2 installed in the separation unit 520a, and supplies fine fragments P below the screen F2. In the separation section 520a where the screen F2 is installed, an upper discharge section B is provided above the screen F2 for discharging the SAP 12 that has floated to the surface of the solvent 220 to the outside by overflow, and a lower discharge section C that can be opened and closed is provided below the screen F2 for discharging the pulp fibers 11. Furthermore, above the screen F2 and below the upper discharge section B, there is an upward-opening inlet section D into which the solvent 220 is injected in order to discharge the pulp fibers 11 from the lower discharge section C.

[0148] As shown in Figure 3, a solvent tank T2 containing solvent 220 is connected to the absorbent separation unit 520 via a pump and valves. When the valve is open, the pump drives the solvent 220 from the solvent tank T2 into the treatment tank of the absorbent separation unit 520. When the pump is stopped or the valve is closed, the supply of solvent 220 from the solvent tank T2 into the treatment tank is stopped. Thus, the solvent 220 is pumped from the solvent tank T2 and introduced into the treatment tank through opening A and inlet D of the absorbent separation unit 520. When the solvent is injected into opening A, at least the lower discharge section C is closed.

[0149] As shown in Figure 5, in this embodiment 1, first, fine fragments P are introduced into the opening A of the processing tank of the absorbent separation unit 520. Subsequently, by opening a valve located between the connection between the absorbent separation unit 520 and the solvent tank T2, and operating a pump, the solvent 220 in the solvent tank T2 is introduced into the absorbent separation unit 520 through opening A, filling the processing tank of the absorbent separation unit 520 to a predetermined position below the screen F2, and immersing the fine fragments P in the solvent 220 within the processing tank of the absorbent separation unit 520. That is, in this embodiment 1, due to the configuration of the separation unit 520a and input unit 520b of the absorbent separation unit 520 described above, the fine fragments P introduced from opening A of the absorbent separation unit 520 are sent below the screen F2 installed in the separation unit 520a and immersed in the solvent 220 below the screen F2. Preferably, the solvent 220 in which the fine fragments P are immersed is stirred with a stirring means such as a stirrer. Alternatively, the treatment tank itself is oscillated to vibrate the solvent 220. This disperses the fine fragments P, promoting the separation of SAP 12 and pulp fibers 11, and improving treatment efficiency. In addition, to prevent the liquid level of the solvent 220 and splashes from reaching the screen F2 due to the stirring and vibration at this time, the liquid level of the solvent 220 injected into the treatment tank is kept at a sufficient distance from the screen F2.

[0150] In this embodiment 1, a halogenated hydrocarbon-based dry cleaning solvent 220 is used as the solvent 220, having a specific gravity higher than that of the pulp fibers 11 and SAP 12 of the absorbent body 10, and having a specific gravity of 1.5 or more and 1.8 or less. Preferably, it is tetrachloroethylene.

[0151] Next, in the processing tank of the absorbent separation unit 520, the introduced fine fragments P are immersed in the solvent 220, and when the solvent 220 is stirred, the fine fragments P are dispersed in the solvent 220 and become suspended. When the stirring is stopped after the fine fragments P have dispersed in the solvent 220, the specific gravity of SAP 12 is lower than that of the solvent 220, and SAP 12 is also smaller than the specific gravity and dimensions of the pulp fibers 11, and does not absorb the solvent 220, so the granular SAP 12 among the fine fragments P floats to the surface of the liquid.

[0152] Next, when the SAP 12 floats above the pulp fibers 11, solvent 220 is added from the opening A of the input section 520b of the absorbent separation section 520, raising the liquid level of solvent 220 in the separation section 520a. As a result, the granular SAP 12 passes through the screen F2, while the cotton-like pulp fibers 11 do not pass through the screen F2 and remain below the screen F2. Furthermore, when the liquid level of solvent 220 in the separation section 520a is raised to the position of the upper discharge section B by injecting solvent 220, the solvent 220 on which the SAP 12 that has passed through the screen F2 floats overflows from the upper discharge section B and is discharged to the outside. In other words, by injecting the solvent 220, the SAP 12 that has passed through the screen F2 is overflowed from the upper discharge section B together with the solvent 220, thereby discharging particulate matter P2 such as SAP 12 together with the solvent 220 from the external discharge section B. Next, after the particulate matter P2 such as SAP12 is discharged from the upper discharge section B together with the solvent 220, the lower discharge section C and the inlet section D are opened, and the solvent 220 is injected from the opening of the inlet section D of the absorbent separation section 520, thereby introducing the solvent 220 from above the screen F2, and the fibrous matter P1 such as pulp fibers 11 is discharged from the opened lower discharge section C together with the solvent 220.

[0153] Thus, in this embodiment 1, a screen F2 is installed in the absorbent separation unit 520, a solvent 220 is placed in the processing tank, and fine fragments P are introduced below the position of the screen F2. By immersing the fine fragments P in a halogenated hydrocarbon dry cleaning solvent 220 such as tetrachloroethylene with a specific gravity of 1.5 or more and 1.8 or less, the SAP 12 of the fine fragments P float to the surface above the screen F2 due to gravity caused by the difference in specific gravity between the solvent 220 and the fine fragments P, and because the SAP 12 is smaller in size than the pores of the screen F2, while the pulp fibers 11 of the fine fragments P remain below the screen F2. As a result, the granular material P2 such as SAP 12 that floats above the screen F2 and the fibrous material P1 such as pulp fibers 11 that remains below the screen F2 are separated. Therefore, the granular material P2 such as SAP 12 and the fibrous material P1 such as pulp fibers 11 can be recovered separately. Specifically, by separating the particulate matter P2, such as SAP12, that passes through screen F2 and floats to the liquid surface above screen F2, from the fibrous matter P1, such as pulp fibers 11, that remains below screen F2, the particulate matter P2, such as SAP12, is discharged from the upper discharge section B, and the fibrous matter P1, such as pulp fibers 11, is discharged from the lower discharge section C, thereby allowing the particulate matter P2, such as SAP12, and the fibrous matter P1, such as pulp fibers 11, to be recovered separately.

[0154] The solvent 220 containing particulate matter P2 such as SAP12, discharged from the upper discharge section B of the separation section 520a by overflow, is sent to the filtration section 562, where it is separated into the solvent 220 and the particulate matter P2 such as SAP12. The particulate matter P2 such as SAP12, separated from the solvent 220, is then sent to the drying section 550, where it is dried by hot air drying, vacuum drying, etc., and desolvented. Furthermore, since the dried particulate matter P2 such as SAP12 may contain other constituent materials such as elastic thread 25, these other constituent materials are removed using a screen or the like. High-quality SAP12 is recovered as a result.

[0155] The solvent 220 containing fibrous material P1 such as pulp fibers 11, discharged from the lower discharge section C of the separation section 520a, is sent separately from particulate material P2 such as SAP 12 to the filtration section 561, where it is separated into solvent 220 and fibrous material P1 such as pulp fibers 11. The fibrous material P1 separated from the solvent 220 is then sent to the drying section 550, where it is dried with hot air or the like to remove the solvent. Furthermore, since the dried fibrous material P1 such as pulp fibers 11 may contain other constituent materials such as rubber threads 25 and short fibers such as rayon and synthetic fibers, these other constituent materials are removed using a screen or the like. As a result, high-quality pulp fibers 11 are recovered. The filtration methods in the filtration sections 561 and 562 include, for example, filter filtration and sedimentation separation.

[0156] Furthermore, the other constituent materials, such as the rubber yarn 25, rayon, and synthetic fibers separated from the SAP 12 and pulp fibers 11, can be recycled together with the separately collected coarse pieces L, such as the sheets 20, through thermal recycling, material recycling, or chemical recycling as solid fuel, plastic raw materials, or generated oil.

[0157] In this embodiment 1, the filtration units 561 and 562 are connected to the solvent tank T2 by a solvent circulation path 540. A fine-mesh filter (not shown) is installed in the middle of the solvent circulation path 540. The solvent 220 discharged from the filtration units 561 and 562 is filtered to remove fine foreign matter and then supplied to the solvent tank T2, where it is reused as solvent 220 for separating the pulp fibers 11 and SAP 12 in a wet state. The solvent gas exhaust from drying the fibrous material P1 such as pulp fibers 11 and particulate material P2 such as SAP 12 in the drying unit 550 may also be cooled and supplied to the solvent tank T2 for reuse as solvent 220 for separating the pulp fibers 11 and SAP 12.

[0158] In particular, the pulp fibers 11 and SAP 12 separated from the sheet 20 are dried in the drying section 550 to volatilize the solvent 120 before being fed to the absorbent separation section 520. This prevents the solvent 120 in which the adhesive adhering to the pulp fibers 11 and SAP 12 has been dissolved from mixing with the solvent 220 used in the absorbent separation section 520 to separate the pulp fibers 11 and SAP 12. Therefore, even when the solvent 220 used to separate the pulp fibers 11 and SAP 12 in the absorbent separation section 520 is recovered and reused, purification to separate the solvent 120 in which the adhesive has been dissolved is not required, thus simplifying the apparatus and reducing costs.

[0159] Thus, in this embodiment 1, the pulp fibers 11 and SAP 12 are separated by utilizing the flotation of SAP 12 in solvent 220, which has a higher specific gravity than SAP 12, and the screen F2. This allows for highly accurate and efficient separation of SAP 12 and pulp fibers 11 under extremely low-impact, gentle conditions, without expending energy that degrades the sheet 20, pulp fibers 11, SAP 12, etc. Therefore, pulp fibers 11 and SAP 12 can be recovered with extremely high quality.

[0160] Next, another embodiment of the separation and recovery method and separation and recovery apparatus for separating and recovering the constituent materials of unused absorbent articles in this embodiment will be described with reference to Figure 6. In this embodiment 2, the processing tank, which serves as a solvent processing unit 510 equipped with separation and recovery means such as a screen F1, has a cylindrical rotating drum R supported on its circumferential surface. The screen F1 has holes of a diameter that allow the pulp fibers 11 and SAP 12 of the absorbent body 10 and the solvent 120 to pass through, but not through the sheet 20. A solvent tank T1 containing the solvent 120 is connected to the processing tank of the solvent processing unit 510 via a pump and valves. When the valve is open, the pump drives the solvent 120 in the solvent tank T1 into the rotating drum R of the solvent processing unit 510. When the pump is stopped or the valve is closed, the supply of the solvent 120 from the solvent tank T1 to the rotating drum R is stopped. Thus, the solvent 120 into which the material to be processed 110 is immersed in the rotating drum R is pumped up from the solvent tank T1 and placed into the rotating drum R to a predetermined liquid level. In this second embodiment as well, a petroleum-based dry cleaning solvent 120 was used, which had a specific gravity of 0.6 or higher and 0.8 or lower, and was smaller than the specific gravity of the pulp fibers 11 and SAP 12 of the absorbent material 10.

[0161] The workpiece 110 is placed inside the rotating drum R, and by opening a valve located between the solvent processing unit 510 and the solvent tank T1, and operating the pump, the solvent 120 in the solvent tank T1 is poured into the rotating drum R to a predetermined liquid level, and the rotating drum R is rotated, causing the solvent 120 containing the workpiece 110 to be agitated. As a result, the workpiece 110 is immersed in the solvent 120 inside the rotating drum R, and the adhesive in the workpiece 110 dissolves in the solvent 120, causing the workpiece 110 to decompose, dissociate, and break down, and the constituent materials of the workpiece 110 are scattered into the solvent 120. Then, due to the centrifugal force of the rotating drum R, the pulp fibers 11 and SAP 12 of the absorber 10 and the solvent 120 of the material to be processed 110 pass through the screen F1 provided on the circumferential surface of the rotating drum R and are discharged outside the rotating drum R, while the sheet 20 remains inside the rotating drum R. As a result, coarse pieces L such as the sheet 20 are separated from fine pieces P such as the pulp fibers 11 and SAP 12 of the absorber 10 and the solvent 120.

[0162] In the solvent treatment unit 510, coarse fragments L such as sheets 20 remaining in the rotating drum R are discharged and recovered outside the solvent treatment unit 510 using, for example, airflow or liquid flow. The coarse fragments L such as sheets 20 discharged from the solvent-treated material 510 are transported to a drying unit 550 equipped with drying means, where they are dried with hot air or the like. They are then thermally recycled, materially recycled, or chemically recycled as solid fuel, plastic raw material, or generated oil. Furthermore, since the dried coarse pieces L of the sheet 20 may contain other constituent materials such as elastic thread 25 and labels, the nonwoven fabric or film sheet 20 and the other constituent materials such as elastic thread 25 may be separated, collected separately, and recycled separately.

[0163] The solvent 120 containing pulp fibers 11 and SAP 12, which is discharged from the outer casing outside the rotating drum R in the solvent processing unit 510, is discharged from the solvent processing unit 510 and further sent to the liquid cyclone HC, where it is separated into pulp fibers 11 and solvent 120 and SAP 12. The liquid cyclone HC has an inlet on the upper side of a cone, a lower outlet at the lower end of the cone, and an upper outlet at the center of the upper surface of the cone. When solvent 120 containing pulp fibers 11 and SAP 12 is pumped into the inlet of the liquid cyclone HC, the granular SAP 12 in the fluid descends while swirling along the inner surface of the cone due to the centrifugal force of the vortex flow and is discharged from the lower outlet, and the pulp fibers 11 reverse direction and rise near the bottom along with the solvent 120 and are discharged from the upper outlet, thereby separating the pulp fibers 11 and solvent 120 from the SAP 12.

[0164] The particulate matter P2, such as SAP12, discharged from the lower discharge section of the liquid cyclone HC is sent to the drying section 550, where it is dried with hot air or the like and desolvented. Furthermore, since the dried particulate matter P2, such as SAP12, may contain other constituent materials such as rubber thread 25, these other constituent materials are removed using a screen or the like. High-quality SAP12 is recovered as a result.

[0165] The solvent 120 containing fibrous material P1 such as pulp fibers 11, discharged from the upper discharge section of the liquid cyclone HC, is sent to the filtration section 561, where it is separated into the solvent 120 and the fibrous material P1 such as pulp fibers 11. The fibrous material P1 separated from the solvent 120 is then sent to the drying section 550, where it is dried with hot air or the like to remove the solvent. Furthermore, since the dried fine fibrous material P1 such as pulp fibers 11 may contain other constituent materials such as rubber threads 25 and short fibers such as rayon and synthetic fibers, these other constituent materials are removed using a screen or the like. As a result, high-quality pulp fibers 11 are recovered.

[0166] In this embodiment 2, the filtration unit 561 is connected to the distillation unit 530, and the solvent 120 discharged from the filtration unit 561 is supplied to the distillation unit 530, where it is distilled. The solvent 120 discharged from the filtration section 561 may be recovered once in a solvent recovery tank located between the filtration section 561 and the distillation section 530, and then supplied to the distillation section 530. The solvent gas exhaust from drying the sheets 120, pulp fibers 11, SAP 12, etc. in the drying section 550 may also be cooled and supplied to the solvent recovery tank and distillation section 530. Since the adhesive contained in the object to be treated 110 is dissolved in the solvent 120 into which the object to be treated 110 was immersed, the adhesive precipitates when the solvent 120 after the immersion treatment of the object to be treated 110 is distilled in the distillation section 530, and the adhesive is then separated and recovered.

[0167] Furthermore, in this embodiment 2 as well, the distillation section 530 is connected to the solvent tank T1 by a solvent circulation path 540, and a filtration section equipped with a fine-mesh filter for removing foreign matter is provided in the middle of the solvent circulation path 540. From here, the solvent gas evaporated in the distillation section 530 is cooled and condensed to produce a liquid solvent 120. After fine foreign matter is filtered out by the filter in the filtration section, the solvent is sent to the solvent tank T1 and reused as solvent 120 for immersion treatment of the workpiece 110.

[0168] Thus, in this embodiment 2, the centrifugal force of the rotating drum R in the solvent treatment unit 510, the screen F1, and the liquid cyclone HC are used to separate the sheet 20, the pulp fibers 11, and the SAP 12, enabling separation with higher precision.

[0169] Incidentally, the inventors have been investigating various solvents 120 shown in Table 1 to dissolve the adhesive of the workpiece 110. In this study, a diaper was used as the absorbent material to be treated (110), and it was immersed in various solvents shown in Table 1 (the amount of solvent 120 used was consistent). To immerse the material 110 in the solvent 120, the diaper was laid flat and placed in a container. A sufficient amount of solvent was added to completely submerge the diaper, and the mixture was stirred.

[0170] [Table 1]

[0171] In any of the solvents 120 shown in Table 1, when the workpiece 110 was added and the solvent 120 was stirred, the adhesive in the workpiece 110 dissolved in the solvent 120, causing the workpiece 110 to decompose and break down, and its constituent materials to scatter. Here, for each solvent 120, the penetration of the solvent 120 into the workpiece 110 when the workpiece 110 was immersed in the solvent 120 was visually confirmed and evaluated on a three-point scale: good (A), acceptable (B), and unacceptable (C). Furthermore, the constituent materials such as the sheet 20 (PP / PE), pulp fibers 11, and SAP 12, which were scattered and separated from the workpiece 110 after immersion in the solvent 120, were visually inspected for any remaining adhesive, and the solubility of the adhesive was evaluated in three stages: no adhesive residue: good (A), some adhesive residue: good (B), and a large amount of adhesive residue: poor (C). Furthermore, the extracted sheet 20, pulp fibers 11, SAP 12, and other constituent materials were air-dried and evaluated on a three-point scale: excellent quick-drying properties: good (A), good quick-drying properties: good (B), and poor quick-drying properties: poor (C).

[0172] Furthermore, the odor of solvent 120 was evaluated on a three-point scale: no noticeable odor (A), a faint odor that could be detected (B), and a strong odor (C). In addition, the residual odor of solvent 120 was checked on the constituent materials such as the removed and dried sheet 20, pulp fibers 11, and SAP 12, and evaluated on a three-point scale: no noticeable odor (A), a faint odor that could be detected (B), and a strong residual odor (C).

[0173] In addition, the color residue of the solvent 120 on the constituent materials such as the removed and dried sheets 20, pulp fibers 11, and SAP 12 was visually inspected and evaluated in three stages: no discoloration: good (A), slight discoloration but hardly noticeable: acceptable (B), and noticeable discoloration: unacceptable (C). Furthermore, changes due to oxidative degradation of solvent 120 were examined and evaluated in three stages: good (A) for those that did not discolor or harden and were resistant to oxidative degradation, good (B) for those with slight discoloration or hardening, and poor (C) for those that discolored or hardened and were prone to oxidative degradation. Furthermore, the changes in properties of the constituent materials such as the removed and dried sheet 20, pulp fibers 11, and SAP 12 were evaluated in three stages: no change in properties for any of the constituent materials: good (A), slight changes in properties that are hardly noticeable: good (B), and changes in properties that are unsuitable for reuse: poor (C).

[0174] As shown in Table 1, paraffin-containing petroleum solvents such as Dry Solvent High Soft and Cleaning Solvent NW-S, as well as halogenated hydrocarbon solvents such as tetrachloroethylene and trichloroethylene, used as dry cleaning solvents, all exhibited good penetration into the workpiece 110, sufficiently dissolving the adhesive in the workpiece 110 without leaving any adhesive residue, and also had good quick-drying properties. In particular, the separated and recovered constituent materials did not retain the odor or color of the solvent 120, and furthermore, the solvent 120 was less prone to oxidative degradation, making it suitable for reuse, and it did not alter the constituent materials of the workpiece 110.

[0175] In contrast, while kerosene showed good penetration into the workpiece 110 and good solubility of the adhesive, it was inferior to petroleum-based solvents and halogenated hydrocarbon solvents such as tetrachloroethylene and trichloroethylene used in dry cleaning in terms of adhesive quick-drying, odor retention, color retention, and oxidative degradation of the solvent 120. Therefore, for solvent 120, it is preferable to use petroleum-based solvents used in dry cleaning, or halogenated hydrocarbon solvents such as tetrachloroethylene and trichloroethylene.

[0176] In other words, kerosene and similar solvents have a distinctive, strong odor, and even after drying, the characteristic odor of solvent 120 remains in the constituent materials such as sheet 20, pulp fibers 11, and SAP 12. Furthermore, they are prone to oxidation and hardening in the air, making them unsuitable for repeated use due to their susceptibility to oxidative degradation. In contrast, petroleum-based solvents containing paraffin, which are used in dry cleaning solvents, or halogenated hydrocarbon solvents such as tetrachloroethylene and trichloroethylene, do not have the odor of solvent 120, offer good handling and working environment, and do not leave any residual odor of solvent 120 in the constituent materials such as sheet 20, pulp fibers 11, and SAP 12. Therefore, they are suitable for reuse in a wide range of applications, and the recovered constituent materials such as sheet 20, pulp fibers 11, and SAP 12 are of high quality. Moreover, these solvents themselves are less prone to oxidative degradation, making them suitable for repeated use, reducing the cost of wastewater disposal, and resulting in a low-cost use of solvent 120.

[0177] Furthermore, according to the inventors' experimental research, halogenated hydrocarbon tetrachloroethylene is particularly suitable as an absorbent separation solvent 220 for separating pulp fibers 11 and SAP 12. Specifically, in the halogenated hydrocarbon tetrachloroethylene solvent 220, particulate SAP 12 floats to the surface, and by utilizing the flotation of SAP 12 and the screen F2, SAP 12 and pulp fibers 11 can be separated efficiently and with high precision in a short time with low load on the pulp fibers 11 and SAP 12. Therefore, high-quality pulp fibers 11 and SAP 12 can be recovered.

[0178] As described above, the method for separating and recovering the constituent materials of an absorbent article (recycling method) according to the above embodiment comprises a solvent treatment step (step S1) in which an unused absorbent article (object to be treated 110), which is made by joining a sheet 20 containing pulp fibers 11 and SAP 12 as absorbents 10 with an adhesive, is immersed in a solvent 120 to dissolve the adhesive in the solvent 120; a separation and recovery step (step S2) in which the constituent materials of the absorbent article (object to be treated 110), which are the sheet 20, pulp fibers 11, and SAP 12, etc., from which the adhesive has been dissolved and removed, are separated and recovered; and a drying step (step S3) in which the separated and recovered constituent materials, such as the sheet 20, pulp fibers 11, and SAP 12, etc., are dried.

[0179] According to the method for separating and recovering the constituent materials of the absorbent article described above, the adhesive joining the constituent members of the unused absorbent article (object to be processed 110) is dissolved in the solvent 120 and removed from the absorbent article (object to be processed 110), thereby dismantling the absorbent article (object to be processed 110) and separating and recovering its constituent materials, such as the sheet 20, pulp fibers 11, and SAP 12. As the adhesive of the absorbent article (object to be processed 110) is dissolved and removed, the absorbent article (object to be processed 110) is easily dismantled, and its constituent materials, such as the sheet 20, pulp fibers 11, and SAP 12, are easily dissociated and separated. Therefore, it is possible to improve the recovery rate of the constituent materials of the unused absorbent article (object to be processed 110), such as the sheet 20, pulp fibers 11, and SAP 12. In particular, by removing the adhesive from the absorbent article (processed object 110), the constituent materials of the absorbent article (processed object 110), such as the sheet 20, pulp fibers 11, and SAP 12, can be accurately separated and recovered without requiring much effort, without having to apply a large amount of energy that would cause the constituent materials such as SAP 12 to be granulated or pulverized. In other words, the constituent materials such as SAP 12 of the absorbent article (processed object 110) can be separated and recovered without being granulated or pulverized. Therefore, the constituent materials of the absorbent article (processed object 110), such as the sheet 20, pulp fibers 11, and SAP 12, can be separated and recovered with high quality. In particular, the SAP 12 and pulp fibers 11 of the absorbent body 10 can be separated and recovered while maintaining their original properties as constituent materials of the absorbent article without being granulated or pulverized, and since the adhesive is also removed, it is suitable for material recycling and is also suitable for recycling the absorbent article as an absorbent body 10.

[0180] Furthermore, the constituent materials of the absorbent article (object to be processed 110) are separated and recovered before the drying process (step S3). Since the constituent materials of the absorbent article (object to be processed 110) are separated and recovered in a wet manner, it is possible to separate and recover the constituent materials with high separation accuracy under conditions that place a low load on the constituent materials and save energy, compared to the dry method.

[0181] In other words, according to the separation and recovery method for the constituent materials of the absorbent article of the above embodiment, the separation and recovery step (step S2) involves immersing the absorbent article (object to be treated 110) in the solvent 120 and separating the constituent materials of the absorbent article (object to be treated 110) in the solvent 120. Therefore, the constituent materials of the absorbent article (object to be treated 110) that have been disassembled in the solvent 120 in which the adhesive has been dissolved are separated using gravity, centrifugal force, specific gravity difference, etc., and filtration separation using screens F1, F2, etc. As a result, since the separation is wet, the sheet 20 and the absorbent 10 can be separated accurately under low-load and energy-saving conditions. Consequently, by being able to separate the sheet 20 and the absorbent 10 accurately under low-cost, energy-saving, and low-load conditions, the absorbent can be recovered in high quality at low cost and energy-saving, and the recovery rate can be improved.

[0182] Furthermore, according to the method for separating and recovering the constituent materials of the absorbent article of the above embodiment, the separation and recovery step (step S2) includes a sheet separation and recovery step in which the absorbent article (object to be treated 110) is immersed in the solvent 120 and separated into a sheet 20 and pulp fibers 11 and SAP 12 as absorbent material 10 in the solvent 120, and an absorbent material separation and recovery step in which the pulp fibers 11 and SAP 12 separated from the sheet 20 are separated into pulp fibers 11 and SAP 12 in a solvent 220 which has a specific gravity higher than SAP 12. First, in the sheet separation and recovery step, the constituent materials of the absorbent article (object to be treated 110) that have been dismantled in the solvent 120 in which the adhesive has been dissolved are separated into a sheet 20 and pulp fibers 11 and SAP 12 as absorbent material 10 by gravity, centrifugal force, specific gravity difference, etc. and filtration separation using a screen F1, etc. Furthermore, in the subsequent absorbent separation and recovery process, the pulp fibers 11 and SAP12 are separated by utilizing the flotation of SAP12 in solvent 220, which has a higher specific gravity than SAP12, and filtration separation using screen F2, etc. Therefore, since this is a wet separation, the sheet 20, pulp fibers 11, and SAP12 can be separated accurately under conditions that are particularly low-impact on SAP12 and energy-saving. Consequently, by being able to separate the sheet 20, pulp fibers 11, and SAP12 accurately under low-cost, energy-saving, and low-impact conditions, the pulp fibers 11 and SAP12 can be recovered in high quality at low cost and energy saving, and the recovery rate can be improved. In other words, the pulp fibers 11 and the superabsorbent polymer 12 can be separated with high recovery efficiency under low-impact conditions. In particular, if the solvent 220 used in the absorbent separation and recovery process has a specific gravity in the range of 1.6 to 1.8, the SAP 12 will float to the surface quickly in the solvent 220, improving separation accuracy and shortening the separation and recovery process. Therefore, separation efficiency can be improved.

[0183] The solvent 120 used to dissolve the adhesive in the absorbent article (object to be treated 110) is a petroleum-based and / or halogenated hydrocarbon-based dry cleaning solvent. Such solvents are less susceptible to oxidative degradation and are suitable for repeated reuse. Furthermore, the odor of the solvent 120 is less likely to remain on the separated and recovered constituent materials such as pulp fibers 11 and SAP 12. Therefore, costs can be reduced, and the separated and recovered constituent materials such as pulp fibers 11 and SAP 12 can be recycled into a wide range of uses without being limited.

[0184] In particular, if the solvent 120 used to immerse the absorbent article (object to be treated 110), that is, the solvent 120 used to dissolve the adhesive of the solvent-absorbing article (object to be treated 110), has a specific gravity in the range of 0.7 to 1.5, the pulp fibers 11 and SAP 12 of the absorbent body 10 will settle in the solvent 120 after the constituent materials of the absorbent article (object to be treated 110) have been immersed in the solvent 120. Therefore, in the solvent 120, the sheet 20 and the absorbent body 10 can be accurately separated under low-impact and energy-saving conditions by sedimentation due to gravity and filtration separation using a screen F1, etc. Consequently, by accurately separating the sheet 20 and the absorbent body 10 under low-cost, energy-saving, and low-impact conditions, the absorbent body 10 can be recovered in high quality at low cost and energy-saving conditions, and the recovery rate can be improved.

[0185] Furthermore, when the pulp fibers 11 and SAP 12 separated from the sheet 20 are dried and then subjected to the absorbent material separation and recovery process, the solvent 120 in which the adhesive adhering to the pulp fibers 11 and SAP 12 is dissolved does not mix with the solvent 220 used to separate the pulp fibers 11 and SAP 12 in the absorbent material separation and recovery process. Therefore, even when the solvent 220 used to separate the pulp fibers 11 and SAP 12 in the absorbent material separation and recovery process is recovered and reused, purification to separate the solvent 120 in which the adhesive is dissolved is not required, thus reducing costs.

[0186] According to the above embodiment of the method for separating and recovering the constituent materials of an absorbent article, by further including an adhesive separation and recovery step (step S4) in which the solvent 120 in which the adhesive is dissolved is distilled and the adhesive is separated and recovered, the adhesive of the absorbent article can be recycled, thus enabling more effective use of resources. In addition, the solvent 120 separated from the adhesive in the adhesive separation and recovery process (step S4) is reused as the solvent 120 used to immerse the absorbent article (object to be treated 110) in the solvent treatment process (step S1), thus conserving resources and reducing costs.

[0187] Furthermore, the above embodiment can also be considered as an invention of an absorbent article component material separation and recovery device (recycling device) comprising: a solvent treatment unit 510 that immerses an unused absorbent article (workpiece 110), which is made by joining a sheet 20 containing pulp fibers 11 and SAP 12 as absorbents 10 with an adhesive, in a solvent 120 to dissolve the adhesive in the solvent 120; a separation and recovery means using screens F1, F2, etc. to separate and recover the sheet 20, pulp fibers 11, SAP 12, etc., which are the constituent materials of the absorbent article (workpiece 110) from which the adhesive has been dissolved and removed; and a drying means using a heater, a vacuum pump, a fan, etc., to dry the separated and recovered constituent materials such as the sheet 20, pulp fibers 11, SAP 12, etc.

[0188] According to the above embodiment of the separation and recovery apparatus for the constituent materials of an absorbent article, the adhesive joining the constituent members of an unused absorbent article (object to be processed 110) is dissolved in the solvent 120 and removed from the absorbent article (object to be processed 110), thereby dismantling the absorbent article (object to be processed 110) and separating and recovering its constituent materials such as the sheet 20, pulp fibers 11, and SAP 12. As a result of dissolving and removing the adhesive from the absorbent article (object to be processed 110), the absorbent article (object to be processed 110) is easily dismantled, and its constituent materials such as the sheet 20, pulp fibers 11, and SAP 12 are easily dissociated and separated. Therefore, it is possible to improve the recovery rate of the constituent materials such as the sheet 20, pulp fibers 11, and SAP 12 of an unused absorbent article (object to be processed 110). In particular, by removing the adhesive from the absorbent article (processed object 110), the constituent materials of the absorbent article (processed object 110), such as the sheet 20, pulp fibers 11, and SAP 12, can be accurately separated and recovered without applying a large amount of energy that would cause the constituent materials such as SAP 12 to be pulverized or pulverized. That is, the constituent materials such as SAP 12 of the absorbent article (processed object 110) can be separated and recovered without being pulverized or pulverized. Therefore, the constituent materials of the absorbent article (processed object 110), such as the sheet 20, pulp fibers 11, and SAP 12, can be separated and recovered with high quality. In particular, the SAP 12 and pulp fibers 11 of the absorbent body 10 can be separated and recovered while maintaining their original properties as constituent materials of the absorbent article without being pulverized or pulverized, and since the adhesive is also removed, it is suitable for material recycling and is also suitable for recycling the absorbent article as an absorbent body 10.

[0189] Furthermore, since the constituent materials of the absorbent article (object to be processed 110) are separated and recovered before drying by the drying means, and the constituent materials of the absorbent article (object to be processed 110) are separated and recovered in a wet manner, it is possible to separate and recover the constituent materials with high separation accuracy under conditions that place a low load on the constituent materials and save energy, compared to the dry method.

[0190] In other words, according to the separation and recovery apparatus for the constituent materials of the absorbent article of the above embodiment, the separation and recovery means separates the constituent materials of the absorbent article (object to be processed 110) in the solvent 120 after immersion treatment of the absorbent article (object to be processed 110) in the solvent 120. Therefore, the constituent materials of the absorbent article (object to be processed 110) that have been disassembled in the solvent 120 in which the adhesive has been dissolved are separated using gravity, centrifugal force, specific gravity difference, etc., and filtration separation using screens F1, F2, etc. Therefore, since the separation is wet, the sheet 20 and the absorbent 10 can be separated accurately under low-load conditions and energy-saving conditions. Consequently, by being able to separate the sheet 20 and the absorbent 10 accurately under low-cost, energy-saving, and low-load conditions, the absorbent can be recovered in high quality at low cost and energy saving, and the recovery rate can be improved.

[0191] Furthermore, according to the separation and recovery apparatus for the constituent materials of the absorbent article of the above embodiment, the separation and recovery means includes a sheet separation and recovery means using a screen F1 or the like to separate the sheet 20 and the pulp fibers 11 and SAP 12 as absorbent material 10 in the solvent 120 after immersing the absorbent article (object to be processed 110) in the solvent 120, and an absorbent material separation and recovery means using a screen F2 or the like to separate the pulp fibers 11 and SAP 12 separated from the sheet 20 into pulp fibers 11 and SAP 12 in a solvent 220 with a specific gravity higher than SAP 12. First, the sheet separation and recovery means separates the constituent materials of the absorbent article (object to be processed 110) that have been dismantled in the solvent 120 in which the adhesive has been dissolved, using gravity, centrifugal force, specific gravity difference, etc., and filtration separation using a screen F1 or the like to separate the sheet 20 and the pulp fibers 11 and SAP 12 as absorbent material 10. Furthermore, the absorbent separation and recovery means separates the pulp fibers 11 and SAP 12 by utilizing the flotation of SAP 12 in solvent 220, which has a higher specific gravity than SAP 12, and filtration separation using screen F2 or the like. Therefore, since the separation is wet, the sheet 20, pulp fibers 11, and SAP 12 can be separated accurately under conditions that are particularly low-impact on SAP 12 and energy-saving. Consequently, by being able to separate the sheet 20, pulp fibers 11, and SAP 12 accurately under low-cost, energy-saving, and low-impact conditions, the pulp fibers 11 and SAP 12 can be recovered in high quality at low cost and energy saving, and the recovery rate can be improved. In other words, the pulp fibers 11 and the superabsorbent polymer 12 can be separated with high recovery efficiency under low-impact conditions. In particular, if the solvent 220 used in the absorbent separation and recovery means has a specific gravity in the range of 1.6 to 1.8, the SAP 12 will float to the surface quickly in the solvent 220, thereby improving separation accuracy and shortening the separation and recovery process. Therefore, separation efficiency can be improved.

[0192] Then, the pulp fibers 11 and SAP 12 separated from the sheet 20 are dried and then subjected to the absorbent separation and recovery means, in which the solvent 120 in which the adhesive attached to the pulp fibers 11 and SAP 12 is dissolved is used for absorbent separation. RecoveryThe solvent 220 used to separate the pulp fibers 11 and SAP 12 is not mixed in at the stage. Therefore, even when the solvent 220 used to separate the pulp fibers 11 and SAP 12 is recovered and reused by the absorbent separation and recovery means, purification to separate it from the solvent 120 in which the adhesive is dissolved is not required, thus reducing costs.

[0193] Furthermore, the separation and recovery apparatus for the constituent materials of the absorbent article according to the above embodiment is further equipped with a distillation unit 530 as an adhesive separation and recovery means that distills the solvent 120 in which the adhesive has dissolved and separates and recovers the adhesive, thereby enabling the recycling of the adhesive of the absorbent article and further effective utilization of resources. In addition, adhesive separation Recovery By providing a solvent circulation path 540 that allows the solvent 120 separated from the adhesive in each stage to be reused as a solvent 120 for immersion treatment of absorbent articles (objects to be treated 110) in the solvent treatment area 510, the solvent 120 separated from the adhesive by the adhesive separation and recovery means is reused as a solvent 120 for immersion treatment of absorbent articles (objects to be treated 110), thereby conserving resources and reducing costs.

[0194] Furthermore, the above embodiment can also be considered an invention of a method for manufacturing recycled unused absorbent material 10, comprising: a solvent treatment step (step S1) in which an unused absorbent article (object to be treated 110), which is made by joining a sheet 10 containing pulp fibers 11 and a superabsorbent polymer (SAP) 12 as an absorbent material 10 with an adhesive, is immersed in a solvent 120 to dissolve the adhesive in the solvent 120; a separation and recovery step (step S2) in which the sheet 10, pulp fibers 11, and SAP 12 of the absorbent article (object to be treated 110) from which the adhesive has been dissolved and removed are separated and recovered; and a drying step (step S3) in which the separated and recovered pulp fibers 11 and SAP 12 are dried.

[0195] In the method for manufacturing recycled unused absorbent material 10 according to the above embodiment, the adhesive joining the components of the unused absorbent article (object to be processed 110) is dissolved in solvent 120 and removed from the absorbent article (object to be processed 110), thereby dismantling the absorbent article (object to be processed 110) and separating and recovering its constituent materials such as sheet 20, pulp fibers 11, and SAP 12. As a result of dissolving and removing the adhesive from the absorbent article (object to be processed 110), the absorbent article (object to be processed 110) is easily dismantled, and its constituent materials such as sheet 20, pulp fibers 11, and SAP 12 are easily dissociated and separated. Therefore, it is possible to improve the recovery rate of pulp fibers 11 and SAP 12, which are constituent materials of the unused absorbent article (object to be processed 110). In particular, by removing the adhesive from the absorbent article (processed object 110), the pulp fibers 11 and SAP 12, which are constituent materials of the absorbent article (processed object 110), can be accurately separated and recovered without applying a large amount of energy that would cause the constituent materials such as SAP 12 to be granulated or pulverized. That is, the constituent materials such as SAP 12 of the absorbent article (processed object 110) can be separated and recovered without being granulated or pulverized. Therefore, the pulp fibers 11 and SAP 12, which are constituent materials of the absorbent article (processed object 110), can be separated and recovered with high quality. In particular, the SAP 12 and pulp fibers 11 of the absorbent body 10 can be separated and recovered while maintaining their original properties as constituent materials of the absorbent article without being granulated or pulverized, and since the adhesive is also removed, the separated and recovered recycled product is of high quality and is suitable for material recycling, and for resource recovery as the absorbent body 10 of the absorbent article.

[0196] In the above embodiment, a solvent treatment step (step S1) is performed in which the adhesive that joined the components of the workpiece 110 is dissolved in the solvent 120 by immersing the workpiece 110 in the solvent 120, followed by a separation and recovery step (step S2) in which the constituent materials such as the sheet 20, cotton-like pulp fibers 11, and granular SAP 12 are separated and recovered individually, and then a drying step (step S3) is performed in which the separated and recovered constituent materials are dried individually or together.

[0197] However, when implementing the present invention, the constituent materials of the workpiece 110 from which the adhesive has been removed by immersion in the solvent 120 may be dried, and then the constituent materials such as the sheet 20, the cotton-like pulp fibers 11, and the granular SAP 12 may be individually separated and recovered. That is, as shown in Figure 6, the separation and recovery method according to a modified embodiment comprises a solvent treatment step (step S1) in which the adhesive joining the components of the workpiece 110 is dissolved in a solvent 120, a drying step (step S21) in which the components of the workpiece 110 from which the adhesive has been removed are dried, and a separation and recovery step (step S22) in which the dried components of the workpiece are individually separated and recovered. In this method, the drying step (step S21) is performed after the solvent treatment step (step S1) to dry the components of the workpiece 110, and then the separation and recovery step (step S3) is performed to separate and recover the components of the workpiece 110.

[0198] Furthermore, a separation and recovery apparatus according to a modified embodiment includes a solvent treatment unit 510 that immerses the workpiece 110 in a solvent to dissolve the adhesive in the solvent 120, a drying means for drying the constituent materials of the workpiece 110 from which the adhesive has been removed by dissolving the adhesive in the solvent 120, and a separation and recovery means for separating and recovering the dried constituent materials.

[0199] In this modified example, the workpiece 110 is immersed in the solvent 120 in the solvent treatment unit 510, and after the adhesive has dissolved into the solvent 120, the constituent materials of the workpiece 110 are collected together and dried. The materials of the workpiece 110 may be dried by discharging and collecting the materials of the workpiece 110 from the solvent treatment unit 510 and drying them in another location, or by discharging the solvent 120 in which the adhesive has been dissolved from the treatment tank of the solvent treatment unit 510 and drying the remaining materials of the workpiece 110 in that treatment tank. Furthermore, the solvent 120 discharged and recovered at this time is also distilled in the distillation section 530 to precipitate the adhesive as a solid, and the solvent 120 and the adhesive are separated and recovered individually. The solvent 120 separated from the adhesive is reused again in the solvent treatment section 510 as solvent 120 to dissolve the adhesive.

[0200] After the adhesive has been removed from the treated object 110, it is dried and desolvented, and then the individual constituent materials are separated and recovered. As a means of separating and recovering each component material, separation can be achieved by utilizing differences in dimensions, specific gravity (bulk density), resistance, drop, etc., of the component materials. For example, as in the above embodiment, screens F1, F2, etc., can be used. Alternatively, separation can be achieved using airflow. By applying an airflow to the constituent materials of the dried workpiece 110, the differences in specific gravity and resistance of the constituent materials can be used to move and separate them. Alternatively, a wind classifier such as a cyclone can be used. In particular, the modified method allows for the separation of the constituent materials of the absorbent article in a dry state, thereby improving the separation accuracy.

[0201] The method for separating and recovering the constituent materials of an absorbent article according to these modified examples comprises a dissolution step (step S1) in which an unused absorbent article (object to be processed 110), which is made by joining a sheet 20 containing pulp fibers 11 and SAP 12 as absorbents 10 with an adhesive, is immersed in a solvent 120 to dissolve the adhesive in the solvent 120; a drying step (step S21) in which the constituent materials of the absorbent article (object to be processed 110), namely the sheet 20, pulp fibers 11, and SAP 12, etc., from which the adhesive has been dissolved and removed, are dried together; and a separation and recovery step (step S22) in which the constituent materials of the dried absorbent article (object to be processed 110), namely the sheet 20, pulp fibers 11, and SAP 12, etc., are separated and recovered.

[0202] Furthermore, the modified apparatus for separating and recovering the constituent materials of an absorbent article comprises a solvent treatment section 510 for immersing an unused absorbent article (object to be treated 110), which is made by joining a sheet 20 containing pulp fibers 11 and SAP 12 as absorbents 10 with an adhesive, in a solvent 120 to dissolve the adhesive in the solvent 120; a drying means using a heater, a vacuum pump, a fan, etc., for drying the constituent materials of the absorbent article (object to be treated 110), such as the sheet 20, pulp fibers 11, and SAP 12, together; and a separation and recovery means using screens F1, F2, etc., for separating and recovering the dried constituent materials of the absorbent article (object to be treated 110), such as the sheet 20, pulp fibers 11, and SAP 12.

[0203] In the method and apparatus for separating and recovering the constituent materials of absorbent articles according to these modified examples, the absorbent article (processed article 110) is dismantled by dissolving the adhesive joining the constituent members of the unused absorbent article (processed article 110) in solvent 120 and removing it from the absorbent article (processed article 110), thereby separating and recovering its constituent materials such as sheet 20, pulp fibers 11, and SAP 12. As a result of dissolving and removing the adhesive from the absorbent article (processed article 110), the absorbent article (processed article 110) is easily dismantled, and its constituent materials such as sheet 20, pulp fibers 11, and SAP 12 are easily dissociated and separated. Therefore, it is possible to improve the recovery rate of the constituent materials of unused absorbent articles (processed article 110), such as sheet 20, pulp fibers 11, and SAP 12. In particular, by removing the adhesive from the absorbent article (processed object 110), the constituent materials of the absorbent article (processed object 110), such as the sheet 20, pulp fibers 11, and SAP 12, can be accurately separated and recovered without applying a large amount of energy that would cause the constituent materials such as SAP 12 to be pulverized or pulverized. That is, the constituent materials such as SAP 12 of the absorbent article (processed object 110) can be separated and recovered without being pulverized or pulverized. Therefore, the constituent materials of the absorbent article (processed object 110), such as the sheet 20, pulp fibers 11, and SAP 12, can be separated and recovered with high quality. In particular, the SAP 12 and pulp fibers 11 of the absorbent body 10 can be separated and recovered while maintaining their original properties as constituent materials of the absorbent article without being pulverized or pulverized, and since the adhesive is also removed, it is suitable for material recycling and is also suitable for recycling the absorbent article as an absorbent body 10.

[0204] Furthermore, the above modified example can also be considered an invention for a method of manufacturing a recycled unused absorbent 10, comprising: a solvent treatment step (step S1) in which an unused absorbent article (object to be treated 110), which is made by joining a sheet 10 containing pulp fibers 11 and a superabsorbent polymer (SAP) 12 as an absorbent body 10 with an adhesive, is immersed in a solvent 120 to dissolve the adhesive in the solvent 120; a drying step (step S21) in which the pulp fibers 11, SAP 12, and sheet 20 of the absorbent article (object to be treated 110) from which the adhesive has been dissolved and removed are dried together; and a separation and recovery step (step S22) in which the pulp fibers 11 and SAP 12 of the dried absorbent article (object to be treated 110) are separated and recovered.

[0205] In the method for manufacturing recycled unused absorbent material 10 according to the above embodiment, the adhesive joining the components of the unused absorbent article (object to be processed 110) is dissolved in solvent 120 and removed from the absorbent article (object to be processed 110), thereby dismantling the absorbent article (object to be processed 110) and separating and recovering its constituent materials such as sheet 20, pulp fibers 11, and SAP 12. As a result of dissolving and removing the adhesive from the absorbent article (object to be processed 110), the absorbent article (object to be processed 110) is easily dismantled, and its constituent materials such as sheet 20, pulp fibers 11, and SAP 12 are easily dissociated and separated. Therefore, it is possible to improve the recovery rate of pulp fibers 11 and SAP 12, which are constituent materials of the unused absorbent article (object to be processed 110). In particular, by removing the adhesive from the absorbent article (processed object 110), the pulp fibers 11 and SAP 12, which are constituent materials of the absorbent article (processed object 110), can be accurately separated and recovered without applying a large amount of energy that would cause the constituent materials such as SAP 12 to be granulated or pulverized. That is, the constituent materials such as SAP 12 of the absorbent article (processed object 110) can be separated and recovered without being granulated or pulverized. Therefore, the pulp fibers 11 and SAP 12, which are constituent materials of the absorbent article (processed object 110), can be separated and recovered with high quality. In particular, the SAP 12 and pulp fibers 11 of the absorbent body 10 can be separated and recovered while maintaining their original properties as constituent materials of the absorbent article without being granulated or pulverized, and since the adhesive is also removed, the separated and recovered recycled product is of high quality and is suitable for material recycling, and for resource recovery as the absorbent body 10 of the absorbent article.

[0206] Incidentally, the absorbent articles described above are based on the premise that the sheets 20 are joined by heat sealing using hot melt adhesive. However, by joining the sheets 20 containing the absorbent material 10 by ultrasonic sealing, which melts and joins the sheets 20 using ultrasonic vibration and pressure, the effort and number of steps required to separate and recover the constituent materials of the absorbent article can be simplified, and the recovery rate of the SAP 12 and pulp fibers 11 of the absorbent material 10 can be improved.

[0207] Furthermore, when implementing the present invention, the configuration, composition, blending, components, shape, quantity, material, size, manufacturing method, etc., of the other parts of the method for separating and recovering absorbent articles, the separation and recovery apparatus, and the method for manufacturing recycled absorbent material 10 are not limited to this embodiment, its modifications, and examples. Also, not all of the numerical values ​​given in this embodiment, its modifications, and examples represent critical values; some numerical values ​​represent suitable values ​​for implementation, so slightly changing the above numerical values ​​does not negate implementation. [Explanation of symbols]

[0208] 10 absorbent material 11 Pulp Fibers 12 Superabsorbent Polymer (SAP) 20 sheets 110. Materials to be processed (absorbent articles)

Claims

1. A solvent treatment step involves immersing an unused absorbent article, which is made by joining sheets containing an absorbent material with an adhesive, in a solvent to dissolve the adhesive in the solvent. A separation and recovery step for separating and recovering the constituent materials of the absorbent article from which the adhesive has been dissolved and removed, A drying step for drying the separated and recovered constituent materials, It is equipped with, A method for separating and recovering the constituent materials of an absorbent article, characterized in that the solvent used to immerse the absorbent article is a petroleum-based and / or halogenated hydrocarbon-based dry cleaning solvent.

2. The method for separating and recovering the constituent materials of an absorbent article according to claim 1, characterized in that the solvent used for immersing the absorbent article has a specific gravity in the range of 0.7 to 1.

5.

3. The method for separating and recovering constituent materials of an absorbent article according to claim 1, characterized in that the separation and recovery step separates the constituent materials of the absorbent article in the solvent.

4. The method for separating and recovering constituent materials of an absorbent article according to claim 1, characterized in that the separation and recovery step includes a sheet separation and recovery step of separating the constituent materials of the absorbent article into the sheet and pulp fibers and a superabsorbent polymer as absorbents in the solvent, and an absorbent material separation and recovery step of separating the absorbent material separated from the sheet into the pulp fibers and the superabsorbent polymer in a solvent with a specific gravity higher than that of the superabsorbent polymer.

5. The method for separating and recovering constituent materials of an absorbent article according to claim 4, characterized in that the pulp fibers and the superabsorbent polymer separated from the sheet are dried before being subjected to the absorbent material separation and recovery step.

6. The method for separating and recovering constituent materials of an absorbent article according to claim 4, characterized in that the solvent used in the absorbent separation and recovery step has a specific gravity in the range of 1.6 to 1.

8.

7. A solvent treatment step involves immersing an unused absorbent article, which is made by joining sheets containing an absorbent material with an adhesive, in a solvent to dissolve the adhesive in the solvent. A drying step of drying the constituent material of the absorbent article from which the adhesive has been dissolved and removed, A separation and recovery step for separating and recovering the constituent materials of the dried absorbent article, It is equipped with, A method for separating and recovering the constituent materials of an absorbent article, characterized in that the solvent used to immerse the absorbent article is a petroleum-based and / or halogenated hydrocarbon-based dry cleaning solvent.

8. Furthermore, the method for separating and recovering constituent materials of an absorbent article according to claim 1 or 7 is characterized by comprising an adhesive separation and recovery step of distilling the solvent in which the adhesive has dissolved and separating and recovering the adhesive.

9. The method for separating and recovering constituent materials of an absorbent article according to claim 8, characterized in that the solvent separated from the adhesive in the adhesive separation and recovery step is reused as a solvent for immersing the absorbent article in the solvent treatment step.

10. A solvent treatment unit is provided for immersing an unused absorbent article, which is made by joining sheets containing an absorbent material with an adhesive, in a solvent to dissolve the adhesive in the solvent. A separation and recovery means for separating and recovering the constituent materials of the absorbent article from which the adhesive has been dissolved and removed, A drying means for drying the separated and recovered constituent materials It is equipped with, A separation and recovery apparatus for the constituent materials of an absorbent article, characterized in that the solvent used for immersion treatment of the absorbent article is a petroleum-based and / or halogenated hydrocarbon-based dry cleaning solvent.

11. The separation and recovery apparatus for the constituent materials of an absorbent article according to claim 10, characterized in that the solvent used to immerse the absorbent article has a specific gravity in the range of 0.7 to 1.

5.

12. The separation and recovery means is characterized by separating the constituent materials of the absorbent article in the solvent, as described in claim 10.

13. The separation and recovery means is characterized by including a sheet separation and recovery means for separating the constituent materials of the absorbent article into at least the sheet and pulp fibers and a superabsorbent polymer as absorbents in the solvent, and an absorbent separation and recovery means for separating the absorbent separated from the sheet into the pulp fibers and the superabsorbent polymer by screen in a solvent with a specific gravity higher than the solvent in which it was immersed, as described in claim 10.

14. The separation and recovery apparatus for constituent materials of an absorbent article according to claim 13, characterized in that the absorbent material separated from the sheet by the sheet separation and recovery means is dried by the drying means and then separated into the pulp fibers and the superabsorbent polymer by the absorbent material separation and recovery means.

15. The separation and recovery apparatus for constituent materials of an absorbent article according to claim 13, characterized in that the solvent used in the absorbent separation and recovery means has a specific gravity in the range of 1.6 to 1.

8.

16. A solvent treatment unit is provided for immersing an unused absorbent article, which is made by joining sheets containing an absorbent material with an adhesive, in a solvent to dissolve the adhesive in the solvent. A drying means for drying the constituent material of the absorbent article from which the adhesive has been dissolved and removed, A separation and recovery means for separating and recovering the constituent materials of the dried absorbent article, It is equipped with, A separation and recovery apparatus for the constituent materials of an absorbent article, characterized in that the solvent used for immersion treatment of the absorbent article is a petroleum-based and / or halogenated hydrocarbon-based dry cleaning solvent.

17. Furthermore, the apparatus for separating and recovering constituent materials of an absorbent article according to claim 10 or 16 is characterized by comprising an adhesive separation and recovery means for distilling the solvent in which the adhesive has dissolved and separating and recovering the adhesive from the solvent.

18. Furthermore, the separation and recovery apparatus for constituent materials of an absorbent article according to claim 17, characterized in that it comprises a solvent circulation path for reusing the solvent separated from the adhesive by the adhesive separation and recovery means as a solvent for immersing the absorbent article in the solvent treatment section.

19. A solvent treatment step involves immersing an unused absorbent article, which is made by joining sheets containing pulp fibers and a superabsorbent polymer as absorbents with an adhesive, in a solvent to dissolve the adhesive in the solvent. A separation and recovery step is performed to separate and recover the sheet, pulp fibers, and superabsorbent polymer of the absorbent article from which the adhesive has been dissolved and removed. A drying step for drying the separated and recovered pulp fibers and the superabsorbent polymer. It is equipped with, A method for producing recycled unused absorbent materials, characterized in that the solvent used to immerse the absorbent material is a petroleum-based and / or halogenated hydrocarbon-based dry cleaning solvent.

20. A solvent treatment step involves immersing an unused absorbent article, which is made by joining sheets containing pulp fibers and a superabsorbent polymer as absorbents with an adhesive, in a solvent to dissolve the adhesive in the solvent. A drying step of drying the constituent material of the absorbent article from which the adhesive has been dissolved and removed, A separation and recovery step for separating and recovering the sheet, pulp fibers, and superabsorbent polymer of the dried absorbent article, It is equipped with, A method for producing recycled unused absorbent materials, characterized in that the solvent used to immerse the absorbent material is a petroleum-based and / or halogenated hydrocarbon-based dry cleaning solvent.

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