Pretreatment Method and Pretreatment Apparatus for Used Absorbent Articles

Abstract

To provide a method for pretreatment of a used absorbent article, capable of stably conducting inactivation of high-absorbing aqueous polymer inside the used absorbent article, and removing stains adhered to the used absorbent article.SOLUTION: The pretreatment method is a method for removing stains used adhered to a used absorbent article including a high-absorbing aqueous polymer and absorbed moisture. The pretreatment method includes immersion step S2 where a used absorbent article 10a is immersed in a first aqueous solution L1 including an inactivator in a first treatment tank 11 while being held with a holding part 12.SELECTED DRAWING: Figure 4

Description

Technical Field

[0001] The present invention relates to a pretreatment method and a pretreatment apparatus for used absorbent articles.

Background Art

[0002] When implementing a treatment process for reusing used absorbent articles, a pretreatment method for removing dirt and absorbed moisture attached to the used absorbent articles is known. For example, Patent Document 1 discloses a treatment method for used paper diapers, which uses a continuous washing machine having a plurality of groups of water washing tanks arranged in series, and sequentially washes the used paper diapers from the front-stage water washing tank to the rear-stage water washing tank while moving them. In this method, the used paper diapers are pre-washed in a pre-washing tank and main-washed in a main-washing tank, and at that time, quicklime (CaO) is mixed with water to dehydrate the superabsorbent polymer.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the method of Patent Document 1, used paper diapers are immersed in an aqueous solution stored in a treatment tank such as a pre-washing tank or a main washing tank to remove dirt adhering to the used paper diapers and to dehydrate the superabsorbent polymer. However, since absorbent articles usually have a specific gravity smaller than that of the aqueous solution even when used and contain air in the gaps between materials (exemplified: gaps between sheets or constituent fibers), they tend to float on the water surface even when put into a water tank. Therefore, even if a used absorbent article is put into a water tank, there is a risk that it cannot be immersed in the aqueous solution. Moreover, there is a risk that an inactivator such as quicklime (CaO) cannot reach the superabsorbent polymer inside the used absorbent article. Then, it is difficult to dehydrate the superabsorbent polymer and to remove the dirt adhering to the used absorbent article. In particular, when used paper diapers are collected in a folded state with the surface sheet on which excrement is excreted facing inward so that the excrement is not exposed on the front side and the odor does not diffuse to the surroundings, this tendency is remarkable.

[0005] An object of the present invention is to provide a method and an apparatus capable of stably inactivating a superabsorbent polymer inside a used absorbent article and removing dirt adhering to the used absorbent article in the pretreatment of the used absorbent article.

Means for Solving the Problems

[0006] One aspect of the present invention is a pretreatment method for removing dirt and absorbed moisture adhering to a used absorbent article, the method comprising an immersion step of immersing the used absorbent article in a first aqueous solution containing an inactivator in a first treatment tank while sandwiching the used absorbent article with a sandwiching portion.

[0007] Another aspect of the present invention is a pretreatment apparatus for removing dirt and absorbed moisture adhering to a used absorbent article, the apparatus comprising a first treatment tank having a first aqueous solution containing an inactivator and a sandwiching portion for sandwiching the used absorbent article, wherein the used absorbent article is configured to be immersed in the first aqueous solution in the first treatment tank while being sandwiched by the sandwiching portion.

Effects of the Invention

[0008] According to the present invention, in the pretreatment of a used absorbent article, a method and an apparatus capable of stably inactivating a superabsorbent polymer inside the used absorbent article and removing dirt attached to the used absorbent article can be provided.

Brief Description of the Drawings

[0009]

Figure 1

Figure 2

Figure 3

Figure 4

Modes for Carrying Out the Invention

[0010] This embodiment relates to the following aspects. [Aspect 1] A pretreatment method for removing dirt and absorbed moisture attached to a used absorbent article containing a superabsorbent polymer, the pretreatment method comprising: an immersion step of immersing the used absorbent article in a first aqueous solution containing an inactivator in a first treatment tank while sandwiching the used absorbent article with a sandwiching portion. The pretreatment method of this aspect includes the above dipping step. In the dipping step, by forcibly dipping the used absorbent article in the first aqueous solution while holding it with the holding part, the air in the gaps between the materials of the used absorbent article can be removed, and the used absorbent article can be filled with the first aqueous solution up to the inside. Thereby, an inactivator can reach the superabsorbent polymer inside the used absorbent article and inactivate (dehydrate) it, and the excrement discharged from the superabsorbent polymer due to inactivation and the dirt attached to the used absorbent article can be made to flow out into the first aqueous solution. Therefore, the used absorbent article can be surely immersed in the first aqueous solution, and the dirt attached to the used absorbent article can be removed and the superabsorbent polymer inside the used absorbent article can be inactivated stably without destroying the used absorbent article. And before the treatment step for reusing the used absorbent article, the weight of the used absorbent article can be reduced, and the efficiency of storage, transportation, etc. before the treatment step and the efficiency of the treatment step itself can be improved. In addition, the removal of dirt and foreign matter in the treatment step can be substantially eliminated. Also, since the inactivation treatment of the superabsorbent polymer can be made unnecessary in the treatment step, the treatment water used in the treatment step can be water, and the load of wastewater treatment of the treatment water in the treatment step can be significantly reduced.

[0011] [Aspect 2] The pretreatment method according to Aspect 1, further comprising a dehydration step of compressing and dehydrating the used absorbent article in a second treatment tank with a compression part after the dipping step. The pretreatment method of this aspect further includes the above dehydration step. In the dehydration step, by compressing the used absorbent article in the second treatment tank while holding it with the compression part, moisture containing water-soluble dirt, etc., which has been released from the superabsorbent polymer and remains inside the used absorbent article, can be released to the outside of the used absorbent article (inside the second treatment tank). In addition, dirt and foreign matter existing in the gaps between the materials of the used absorbent article can be made to flow out to the outside of the used absorbent article together with the moisture, etc. Thereby, the dirt and foreign matter existing inside the used absorbent article can be removed without destroying the used absorbent article.

[0012] [Aspect 3] The pretreatment method according to aspect 2, wherein the first treatment tank and the second treatment tank are the same. In the pretreatment method of this aspect, since the first treatment tank and the second treatment tank are the same, inactivation (dehydration) of the superabsorbent polymer and removal of dirt and foreign matters from the used absorbent article can be performed in a space-saving and efficient manner.

[0013] [Aspect 4] The pretreatment method according to aspect 2 or 3, further comprising a reuse step of transferring, after the dehydration step, the drainage discharged from the used absorbent article and stored in the second treatment tank to the first treatment tank as part or all of the first aqueous solution in the immersion step. The pretreatment method of this aspect further includes the above-mentioned reuse step. In that reuse step, by reusing the drainage stored in the second treatment tank as part or all of the first aqueous solution in the first treatment tank, the usage amount of the aqueous solution obtained by combining the first aqueous solution in the first treatment tank and the drainage in the second treatment tank can be reduced. Thereby, the total amount of drainage can be reduced and the environmental load can be reduced.

[0014] [Aspect 5] The pretreatment method according to any one of aspects 2 to 4, wherein the dehydration step includes a step of compressing the used absorbent article at the compression part and relatively moving it with respect to the second treatment tank while dehydrating. In the pretreatment method of this aspect, in the dehydration step, the used absorbent article is compressed at the compression part and relatively moved with respect to the second treatment tank while dehydrating, so that moisture containing water-soluble dirt released from the superabsorbent polymer and remaining in the used absorbent article, and dirt and foreign matters existing in the gaps between the materials of the used absorbent article can be more easily released to the outside of the used absorbent article (into the second treatment tank). Thereby, dirt and foreign matters existing inside the used absorbent article can be more easily removed.

[0015] [Aspect 6] The pretreatment method according to any one of aspects 2 to 5, wherein the compression part includes a roll press device. In the pretreatment method of this aspect, since the compression unit includes a roll press device, in the dehydration step, the used absorbent article can be easily conveyed by a roll while being compressed, that is, moved relative to the second treatment tank. Thereby, dirt and foreign matter on the used absorbent article can be more easily discharged to the outside and removed.

[0016] [Aspect 7] The pretreatment method according to any one of Aspects 2 to 5, wherein the compression unit includes a compression pusher device. In the pretreatment method of this aspect, since the compression unit includes a pusher device, in the dehydration step, the used absorbent article can be pushed step by step while being compressed, that is, moved relative to the second treatment tank. Thereby, dirt and foreign matter on the used absorbent article can be more easily discharged to the outside and removed.

[0017] [Aspect 8] The pretreatment method according to any one of Aspects 1 to 7, wherein the immersion step includes a step of relatively moving the held used absorbent article relative to the first treatment tank while immersing the held used absorbent article in the first aqueous solution by the holding unit. In the pretreatment method of this aspect, in the immersion step, since the holding unit relatively moves the held used absorbent article relative to the first treatment tank while holding the held used absorbent article, an inactivator can more easily reach the superabsorbent polymer of the used absorbent article. Thereby, the superabsorbent polymer can be more easily inactivated (dehydrated), and excrement discharged from the superabsorbent polymer due to inactivation and dirt attached to the used absorbent article can be more easily discharged into the first aqueous solution.

[0018] [Aspect 9] The pretreatment method according to any one of Aspects 1 to 8, wherein the holding unit includes a pair of conveying conveyors. In the pretreatment method of this aspect, since the clamping part includes a pair of conveying conveyors, in the dipping process, the used absorbent article is clamped and immersed in the first aqueous solution, and conveyed in the first aqueous solution, so that it can be relatively moved in the first treatment tank. Thereby, the superabsorbent polymer can be inactivated (dehydrated) more easily, and the excrement and dirt of the used absorbent article can be more easily discharged into the first aqueous solution.

[0019] [Aspect 10] The pretreatment method according to any one of Aspects 1 to 8, wherein the clamping part includes a clamping pusher device. In the pretreatment method of this aspect, since the clamping part includes a pusher device, in the dipping process, the used absorbent article is clamped and immersed in the first aqueous solution, and pushed step by step in the first aqueous solution, so that it can be relatively moved in the first treatment tank. Thereby, the superabsorbent polymer can be inactivated (dehydrated) more easily, and the excrement and dirt of the used absorbent article can be more easily discharged into the first aqueous solution.

[0020] [Aspect 11] A pretreatment device for removing dirt and absorbed moisture attached to a used absorbent article containing a superabsorbent polymer, comprising a first treatment tank having a first aqueous solution containing an inactivator, and a clamping part for clamping the used absorbent article, wherein the used absorbent article is configured to be immersed in the first aqueous solution in the first treatment tank while being clamped by the clamping part. The pretreatment device of this aspect has the above configuration. Therefore, by forcibly immersing the used absorbent article in the first aqueous solution while holding it with the holding part, the air in the gaps between the materials of the used absorbent article can be removed, and the used absorbent article can be filled with the first aqueous solution up to the inside. Thereby, the inactivator can reach the superabsorbent polymer inside the used absorbent article and inactivate (dehydrate) it, and the excrement discharged from the superabsorbent polymer due to inactivation and the dirt attached to the used absorbent article can be made to flow out into the first aqueous solution. Therefore, the used absorbent article can be surely immersed in the first aqueous solution, and the removal of the dirt attached to the used absorbent article and the inactivation of the superabsorbent polymer inside the used absorbent article can be stably carried out.

[0021] Hereinafter, a pretreatment method and a pretreatment device according to an embodiment will be described. The pretreatment method and the pretreatment device are a method and a device for preliminarily removing dirt and absorbed moisture attached to a used absorbent article in order to reuse the used absorbent article containing a superabsorbent polymer. However, the used absorbent article is an absorbent article used by a user, and includes those that are unused but discarded. Examples of the absorbent article include disposable diapers, urine pads, sanitary napkins, bed sheets, and pet sheets.

[0022] (First Embodiment) First, the pretreatment device according to the first embodiment will be described. FIG. 1 is a block diagram showing a configuration example of a pretreatment device A according to the embodiment. The pretreatment device A is a device that performs pretreatment for removing dirt and absorbed moisture attached to the used absorbent article 10a in order to introduce the used absorbent article 10a into the processing device 50, and implements the pretreatment method described later. The processing device 50 is a device that performs processing for reusing the used absorbent article. The processing device 50 is not particularly limited, and examples thereof include a system that performs processing for separating and recovering a film, a superabsorbent polymer, and pulp fibers from a used absorbent article, as described in Japanese Patent Application Laid-Open No. 2020-183585. In the processing device 50 of the present embodiment, the bag-breaking device of the system is removed.

[0023] The pretreatment device A is provided with an immersion unit 2. In this embodiment, it further includes a bag-breaking unit 1, a dehydration unit 3, and a reuse unit 4.

[0024] The bag-breaking unit 1 breaks the collection bag 10 containing a plurality of used absorbent articles 10a and takes out the plurality of used absorbent articles 10a from the collection bag 10. The bag-breaking unit 1 is not particularly limited as long as it can exhibit the above functions. In this embodiment, the bag-breaking unit 1 includes a bag-breaking blade (not shown) that makes a cut of a predetermined size in the collection bag 10, and a discharging unit (not shown) that individually discharges the used absorbent articles 10a from the cut of the collection bag 10. The discharging unit includes, for example, a device that lifts and shakes the collection bag 10 with the cut facing down. As for their configurations, known devices may be used respectively, or it may be done manually.

[0025] The immersion unit 2 forcibly immerses the used absorbent article 10a in a first aqueous solution containing an inactivator. FIG. 2 is a schematic diagram showing a configuration example of the immersion unit 2 according to the embodiment. The immersion unit 2 includes a first treatment tank 11 having a first aqueous solution L1 containing an inactivator, and a clamping unit 12 that clamps the used absorbent article 10a, and is configured such that the used absorbent article 10a is immersed in the first aqueous solution L1 in the first treatment tank 11 while being clamped by the clamping unit 12.

[0026] The clamping part 12 is not particularly limited as long as it can exhibit the above functions. In the present embodiment, the clamping part 12 includes a pair of conveying conveyors 13 and 14 arranged facing each other. The moving paths of the conveying conveyors 13 and 14 first pass over the first treatment tank 11, pass through the first aqueous solution L1 in the first treatment tank 11 in the middle, and then pass over the first treatment tank 11 again. The conveying conveyor 13 includes a mesh belt 13a through which liquid can permeate and a plurality of rollers 13b for driving and feeding. The moving path of the belt 13a passes through the first aqueous solution L1 in the first treatment tank 11 in the middle. On the other hand, the conveying conveyor 14 includes a mesh belt 14a through which liquid can permeate and a plurality of rollers 14b for driving and feeding. The moving path of the belt 14a passes through the first aqueous solution in the first treatment tank 11 in the middle. Then, the belt 13a and the belt 14a sandwich and convey the used absorbent article 10a.

[0027] Therefore, the clamping part 12 immerses the used absorbent article 10a in the first aqueous solution L1 containing an inactivator in the first treatment tank 11 while clamping it with a pair of conveying conveyors 13 and 14, that is, a pair of belts 13a and 14a. As a result, the used absorbent article 10a becomes a used absorbent article 10b in which the superabsorbent polymer is inactivated by the inactivator contained in the first aqueous solution L1. At that time, the clamping part 12 relatively moves the first treatment tank 11 at a predetermined speed by conveying the clamped used absorbent article 10a in the first treatment tank 11 while immersing it in the first aqueous solution L1.

[0028] The distance between the belt 13a and the belt 14a that sandwich the used absorbent article 10a is preferably substantially constant from the upstream side to the downstream side in the conveyance direction. Thereby, the first aqueous solution L1 (containing the water released from the superabsorbent polymer) can be retained in the materials (exemplified: non-woven fabric, pulp fiber) of the used absorbent article 10b. As a result, the inactivator can be continuously and stably brought into contact with the superabsorbent polymer, and the dirt and foreign matter originally present in the gaps between the materials of the used absorbent article (the gaps between the material bodies and the gaps between the fibers constituting the material bodies) can be easily peeled off from the materials. Incidentally, the distance may be gradually decreased slightly as it advances to the downstream side in the conveyance direction. Thereby, while maintaining the above-described effects, even if the used absorbent article 10b becomes thinner due to the release of water from the superabsorbent polymer, the used absorbent article 10b can be securely sandwiched and conveyed. In that case, the minimum distance is, for example, a distance of 80 to 99% of the maximum distance at the start of sandwiching, and from the viewpoint of reliable sandwiching and the arrival of the aqueous solution, a distance of 85 to 95% is preferable.

[0029] As the first aqueous solution L1 containing an inactivator, an acidic aqueous solution, that is, an aqueous solution of an inorganic acid and an organic acid, is preferable. This is because no ash remains in the plastic material or pulp fiber compared to aqueous solutions such as lime and calcium chloride, and also because it is easy to adjust the degree of inactivation (particle size and specific gravity) with pH. The pH of the acidic aqueous solution is preferably 1.0 to 4.0. When the pH is 1.0 or higher, the equipment is less likely to corrode, and the amount of alkaline chemicals required for neutralization treatment during wastewater treatment can also be reduced. When the pH is 4.0 or lower, the superabsorbent polymer can be made sufficiently small, and the sterilization ability can also be enhanced. Examples of the organic acid include citric acid, tartaric acid, glycolic acid, malic acid, succinic acid, acetic acid, ascorbic acid, etc., and citric acid is preferable. Due to the chelating effect of citric acid, metal ions in excrement, etc. can be trapped and removed, and due to the cleaning effect of citric acid, a high dirt component removal effect can be expected. On the other hand, examples of the inorganic acid include sulfuric acid, hydrochloric acid, and nitric acid, and sulfuric acid is preferable from the viewpoints of not containing chlorine and cost, etc. Since the pH changes with the water temperature, the pH in the present invention is the pH measured at an aqueous solution temperature of 20°C. The concentration of the organic acid in the aqueous solution of the organic acid is not particularly limited, but when the organic acid is citric acid, it is preferably 0.5 mass% or more and 4 mass% or less. The concentration of the inorganic acid in the aqueous solution of the inorganic acid is not particularly limited, but when the inorganic acid is sulfuric acid, it is preferably 0.1 mass% or more and 0.5 mass% or less. In this embodiment, citric acid, an organic acid, is used as the inactivating aqueous solution.

[0030] The temperature of the first aqueous solution L1 is not particularly limited as long as the inactivation reaction proceeds. The temperature may be room temperature, or may be higher than room temperature, for example, 15 to 30°C. Also, the immersion time in the immersion section 2, that is, the time for immersing the used absorbent article 10a in the first aqueous solution L1 containing an inactivator, is not particularly limited as long as the superabsorbent polymer is inactivated and dehydrated, for example, 1 to 60 minutes, preferably 2 to 30 minutes, and more preferably 5 to 20 minutes. The amount of the first aqueous solution L1 containing an inactivator is not particularly limited as long as the used absorbent article 10a can be impregnated, for example, 5 times or more the dry weight of the used absorbent article 10a.

[0031] The dehydration unit 3 compresses and dehydrates the used absorbent article 10b. FIG. 3 is a schematic diagram showing a configuration example of the dehydration unit 3 according to the embodiment. The dehydration unit 3 includes a second treatment tank 21 and a compression unit 22 that compresses and dehydrates the used absorbent article 10b in the second treatment tank 21. The liquid LD discharged from the used absorbent article 10b by the compression unit 22 is stored as drainage L2 in the second treatment tank 21. The drainage L2 is either discharged to the outside or sent to the immersion unit 2 via the reuse unit 4 (described later). However, the dehydration unit 3 may perform compression or the like inside the second treatment tank 21 (above the liquid level of the drainage L2 stored or capable of being stored in the second treatment tank 21), or may perform compression or the like outside the second treatment tank 21 (above the second treatment tank 21) (the same applies hereinafter).

[0032] The compression unit 22 is not particularly limited as long as it can exhibit the above functions. In this embodiment, the compression unit 22 includes a roll press device including a pair of conveyors 23 and 24 arranged facing each other. The conveyor 23 includes a mesh belt 23a through which liquid can permeate and a plurality of rollers 23b for driving and feeding. On the other hand, the conveyor 24 includes a belt 24a and a plurality of rollers 24b for driving and feeding. The belt 23a and the belt 24a sandwich and convey the used absorbent article 10b in the second treatment tank 21 (inside or outside the second treatment tank 21). At this time, each of the plurality of rollers 23b is arranged facing each of the plurality of rollers 24b, and a plurality of pairs of rollers 23b and 24b are formed. Each of the plurality of pairs of rollers 23b and 24b sequentially sandwiches and compresses the used absorbent article 10b.

[0033] The distance between the paired belts 23a and 24a that sandwich the used absorbent article 10b is configured to gradually decrease as it advances downstream in the conveyance direction. That is, the distance between the paired rollers 23b and 24b is configured to be smaller for the pair of rollers 23b and 24b located downstream in the conveyance direction. Thereby, the compression unit 22 can compress the used absorbent article 10b more as it sandwiches and conveys the used absorbent article 10b with the pair of belts 23a and 24a (each pair of rollers 23b and 24b). In that case, the minimum distance is, for example, a distance of 10 to 70% of the maximum distance at the start of sandwiching. From the viewpoints of low damage to the material and reliable compression, a distance of 15 to 60% or less is preferable, and a distance of 20 to 50% is more preferable. Alternatively, the pressure applied to the used absorbent article 10b during compression is, for example, 0.1 to 10 kPa. From the viewpoints of low damage to the material and reliable compression, 0.2 to 5 kPa is preferable, and 0.5 to 2 kPa is more preferable.

[0034] Therefore, the compression unit 22 compresses and dehydrates the used absorbent article 10b in the second treatment tank 21 with a pair of conveyors 23 and 24 which are roll press devices, that is, a pair of belts 23a and 24a, and thus a plurality of pairs of rollers 23b and 24b. Thereby, the used absorbent article 10b becomes the used absorbent article 10c from which the water-soluble dirt and other moisture contained in the used absorbent article 10b and remaining in the used absorbent article 10b after being released from the superabsorbent polymer, and the liquid LD containing dirt and foreign matter existing in the gaps between the materials of the used absorbent article 10b are discharged to the outside. At that time, the compression unit 22 relatively moves the used absorbent article 10b at a predetermined speed with respect to the second treatment tank 21 by conveying the used absorbent article 10b in the second treatment tank 21 while compressing it. Note that the dehydration by the compression unit 22 is physically performed and is different from the chemical dehydration of the superabsorbent polymer by the inactivator. The degree of dehydration is preferably such that the weight of the used absorbent article 10b is reduced to 2 times or less the dry weight of the absorbent article, and more preferably 1.5 times or less the dry weight of the absorbent article, from the viewpoint of reducing moisture, dirt, and foreign matter without destroying the used absorbent article 10b.

[0035] Note that the first treatment tank 11 of the immersion section 2 and the second treatment tank 21 of the dehydration section 3 may be the same. However, "the same" means not only the case where the first treatment tank 11 and the second treatment tank 21 are the same single tank and the clamping section 12 and the compression section 22 are arranged in that tank, but also includes the case where the first treatment tank 11 and the second treatment tank 21 are directly or indirectly connected and integrated and can be regarded as substantially a single tank. For example, it is the case where the first treatment tank 11 and the second treatment tank 21 with different sizes are directly connected, or the case where they are indirectly connected by a water channel through which the aqueous solution can flow freely.

[0036] The reuse section 4 flows the drainage L2 discharged from the used absorbent article 10b and stored in the second treatment tank 21 from the dehydration section 3 to the immersion section 2. The reuse section 4 is not particularly limited as long as it can exhibit the above functions. In the present embodiment, the reuse section 4 is, for example, a liquid feed pump.

[0037] Next, the pretreatment method according to the embodiment will be described. FIG. 4 is a flowchart showing an example of the pretreatment method according to the embodiment. The pretreatment method is a method for removing dirt and absorbed moisture attached to the used absorbent article 10a in order to introduce the used absorbent article 10a into the treatment step S50, and is implemented by the above-described pretreatment apparatus A. The treatment step S50 is a method for performing treatment for reusing the used absorbent article. The treatment step S50 is not particularly limited, but for example, a method for separating and recovering a film, a superabsorbent polymer, and pulp fibers from the used absorbent article described in Japanese Patent Application Laid-Open No. 2020-183585 can be mentioned. In the treatment step S50 of the present embodiment, the punching step of that method is excluded.

[0038] The pretreatment method includes an immersion step S2, and in the present embodiment, further includes a bag-breaking step S1, a dehydration step S3, and a reuse step S4.

[0039] The bag-breaking process S1 is carried out by the bag-breaking part 1, which breaks the collection bag 10 containing a plurality of used absorbent articles 10a and takes out the plurality of used absorbent articles 10a from the collection bag 10. The plurality of taken-out used absorbent articles 10a are conveyed by a conveying device (not shown) to the immersion process S2 (immersion part 2).

[0040] The immersion process S2 is carried out by the immersion part 2. While the used absorbent article 10a is being held by the holding part 12, it is immersed in the first aqueous solution L1 containing an inactivating agent in the first treatment tank 11. Thereby, the used absorbent articles 10a put into the first treatment tank 11 are surely immersed in the first aqueous solution L1 without floating on the water surface, and the air in the gaps between the materials of the used absorbent article 10a (for example, the gaps between sheets or constituent fibers) is replaced by the first aqueous solution L1. Therefore, the superabsorbent polymer in the used absorbent article 10a is inactivated by the inactivating agent contained in the first aqueous solution L1, and the used absorbent article 10a from which the moisture inside the superabsorbent polymer has been released to the outside (dehydrated), that is, the used absorbent article 10b is obtained. Thereafter, the plurality of used absorbent articles 10b are lifted from the first aqueous solution L1 and conveyed to the dehydration process S3 (dehydration part 3).

[0041] The dehydration process S3 is carried out by the dehydration part 3. After the immersion process S2, the used absorbent article is compressed and dehydrated in the second treatment tank by the compression part. Thereby, the area between the materials of the used absorbent article 10b (for example, the area between sheets or constituent fibers) is crushed, and the liquid present in that area is discharged. Therefore, the used absorbent article 10b from which the moisture containing water-soluble dirt released from the superabsorbent polymer in the used absorbent article 10b and remaining in the used absorbent article 10b, as well as the liquid LD containing dirt and foreign substances present in the gaps between the materials of the used absorbent article 10b, has been discharged to the outside, that is, the used absorbent article 10c is obtained. Thereafter, the plurality of used absorbent articles 10c are conveyed by a conveying device (not shown) to the treatment process S50 (treatment device 50).

[0042] The reuse process S4 is carried out in the reuse section 4. After the dehydration process S3, the drainage L2 discharged from the used absorbent article 10c and stored in the second treatment tank 21 is transferred to the first treatment tank 11 as part or all of the first aqueous solution L1 in the immersion process S2. Note that all or part of the drainage L2 may be discharged to the outside (e.g., (industrial) sewer).

[0043] As described above, the pretreatment method is executed (by the pretreatment apparatus A).

[0044] Note that the used absorbent article 10c is subjected to a treatment for reusing the used absorbent article 10c in the treatment process S50.

[0045] The above pretreatment apparatus implements the above pretreatment method. In the pretreatment method (and the pretreatment apparatus), by the above immersion process S2 (immersion section 2), while the used absorbent article 10a is clamped by the clamping section 12 and forcibly immersed in the first aqueous solution L1, the air in the gaps between the materials of the used absorbent article 10a can be removed, and the used absorbent article 10a can be filled with the first aqueous solution L1 up to the inside. Thereby, an inactivator can reach the superabsorbent polymer inside the used absorbent article 10a and inactivate (dehydrate) it, and the excrement discharged from the superabsorbent polymer due to inactivation and the dirt attached to the used absorbent article can be made to flow out into the first aqueous solution L1. Therefore, the above pretreatment apparatus and pretreatment method can surely immerse the used absorbent article 10a in the first aqueous solution L1, and can stably perform the removal of the dirt attached to the used absorbent article 10a and the inactivation of the superabsorbent polymer inside the used absorbent article 10a without destroying the used absorbent article. Moreover, it is possible to reduce the weight of the used absorbent article 10a before the treatment step S50, and it is possible to improve both the efficiency of storage and transportation of the used absorbent article 10a before the treatment step S50 and the treatment efficiency of the treatment step S50. In addition, it is possible to substantially eliminate the need to remove dirt and foreign matter in the treatment step S50. Further, since it is possible to eliminate the need for inactivating the superabsorbent polymer in the treatment step S50, the treatment water used in the treatment step S50 may be water, and the load of wastewater treatment of the treatment water in the treatment step can be significantly reduced.

[0046] In this pretreatment method (and pretreatment apparatus), as a preferred embodiment, in the immersion step S2 (immersion unit 2), the used absorbent article 10a held by the holding unit 12 is relatively moved with respect to the first treatment tank 11 while being held, and thus is moved in the first aqueous solution L1. Therefore, due to the occurrence of a flow in the first aqueous solution L1 or the like, the inactivator of the first aqueous solution L1 can more easily reach the superabsorbent polymer of the used absorbent article 10a. Thereby, the superabsorbent polymer can be more easily inactivated (dehydrated), and the excrement discharged from the superabsorbent polymer due to inactivation and the dirt attached to the used absorbent article 10a can be more easily discharged into the first aqueous solution L1.

[0047] In this pretreatment method (and pretreatment apparatus), as a preferred embodiment, the holding unit 12 includes a pair of conveyor belts 13 and 14. Therefore, in the immersion step S2, the used absorbent article 10a can be held, immersed in the first aqueous solution L1, and conveyed in the first aqueous solution L1 to be relatively moved with respect to the first treatment tank 11. Thereby, the superabsorbent polymer can be more easily inactivated (dehydrated), and the excrement and dirt of the used absorbent article 10a can be more easily discharged into the first aqueous solution L1.

[0048] This pretreatment method (and pretreatment apparatus), in a preferred embodiment, further includes the above-described dehydration step S3 (dehydration unit 3) after the immersion step S2 (immersion unit 2). Therefore, in the dehydration step S3 (dehydration unit 3), the used absorbent article 10b is compressed in the compression unit 22 while being held, and compressed in the second treatment tank 21, so that the water-soluble contaminants and the like, including the water that has been released from the superabsorbent polymer and remained in the used absorbent article 10b, can be discharged to the outside of the used absorbent article 10b (inside the second treatment tank 21). In addition, the contaminants and foreign substances present in the gaps between the materials of the used absorbent article 10b can be caused to flow out to the outside of the used absorbent article 10b together with the water and the like. Thereby, the contaminants and foreign substances present inside the used absorbent article can be removed without destroying the used absorbent article.

[0049] In this pretreatment method (and pretreatment apparatus), in a preferred embodiment, in the dehydration step S3 (dehydration unit 3), the used absorbent article 10b is compressed and dehydrated in the compression unit 22 while being conveyed in the second treatment tank 21, thereby moving it relative to the second treatment tank 21. Therefore, due to the generation of an air flow in the vicinity of the used absorbent article 10b during conveyance, the water-soluble contaminants and the like, including the water that has been released from the superabsorbent polymer and remained in the used absorbent article 10b, and the contaminants and foreign substances present in the gaps between the materials of the used absorbent article 10b can be more easily discharged to the outside of the used absorbent article 10b (inside the second treatment tank 21). Thereby, the contaminants and foreign substances present inside the used absorbent article 10b can be more easily removed.

[0050] In this pretreatment method (and pretreatment apparatus), in a preferred embodiment, the compression unit 22 is provided with a roll press device. Therefore, in the dehydration step S3, the used absorbent article 10b can be easily compressed and sent by the rolls, thereby moving it relative to the second treatment tank 21. Thereby, the contaminants and foreign substances of the used absorbent article 10b can be more easily discharged to the outside and removed.

[0051] In this pretreatment method (and pretreatment apparatus), as a preferred embodiment, the first treatment tank 11 and the second treatment tank 21 are the same. Thereby, inactivation (dehydration) of the superabsorbent polymer of the used absorbent article 10a and removal of dirt and foreign matter from the used absorbent article 10b can be performed in a space-saving and efficient manner.

[0052] This pretreatment method (and pretreatment apparatus) preferably further includes the above-described reuse step S4 (reuse unit 4). Therefore, by the reuse step S4 (reuse unit 4), the drainage L2 stored in the second treatment tank 21 is reused as part or all of the first aqueous solution L1 in the first treatment tank 11, thereby reducing the usage amount of the aqueous solution obtained by combining the first aqueous solution L1 in the first treatment tank 11 and the drainage L2 in the second treatment tank 21. Thereby, the total amount of drainage can be reduced, and the environmental load can be reduced.

[0053] (Second Embodiment) The pretreatment apparatus of the second embodiment is different from the pretreatment apparatus of the first embodiment in that the clamping part of the immersion part 2 and the compression part of the dehydration part 3 are not conveyor devices but pusher devices (not shown). Hereinafter, the differences from the first embodiment will be mainly described.

[0054] The clamping part of the immersion part 2 includes a clamping pusher device. The pusher device is not particularly limited, but as a first example, it is disposed in the first treatment tank 11 and includes a push plate and a cylinder mechanism that pushes the push plate. The pusher device supplies the first aqueous solution L1 into the first treatment tank 11 while clamping the used absorbent article 10a between the inner side surface of the first treatment tank 11 and the push plate. Thereby, the used absorbent article 10a can be forcibly immersed in the first aqueous solution L1 containing the inactivator.

[0055] Alternatively, as a second example, the pusher device is disposed in the first treatment tank 11 and includes a pair of push plates and a cylinder mechanism that pushes each of the pair of push plates. The pusher device supplies the first aqueous solution L1 into the first treatment tank 11 while sandwiching the used absorbent article 10a between the pair of push plates. Thereby, the used absorbent article 10a can be forcibly immersed in the first aqueous solution L1 containing the inactivating agent.

[0056] Alternatively, as a third example, the pusher device is disposed inside or outside the first treatment tank 11 so as to be movable in the vertical direction and includes a pair of push plates and a cylinder mechanism that pushes each of the pair of push plates. The pusher device sandwiches the used absorbent article 10a between the pair of push plates above the first treatment tank 11 and lowers the pair of push plates downward into the first treatment tank 11 storing the first aqueous solution L1 while maintaining that state. Thereby, the used absorbent article 10a can be forcibly immersed in the first aqueous solution L1 containing the inactivating agent.

[0057] The compression part of the dehydration part 3 is provided with a compression pusher device. The pusher device is not particularly limited, but as a first example, it is disposed on the second treatment tank 21 and includes a push plate and a cylinder mechanism that pushes the push plate. The pusher device sandwiches the used absorbent article 10b between the inner surface of the second treatment tank 21 and the push plate and brings the push plate closer to the inner surface of the second treatment tank 21. Thereby, the used absorbent article 10b can be compressed and dehydrated.

[0058] Alternatively, as a second example, the pusher device is disposed on the second treatment tank 21 and includes a pair of push plates and a cylinder mechanism that pushes each of the pair of push plates. The pusher device sandwiches the used absorbent article 10b between the pair of push plates and brings the pair of push plates closer to each other. Thereby, the used absorbent article 10b can be compressed and dehydrated.

[0059] Alternatively, as a third example, the pusher device is disposed within or outside the second treatment tank 21 so as to be movable in the vertical direction, and includes a pair of push plates and a cylinder mechanism that pushes each of the pair of push plates. The pusher device sandwiches the used absorbent article 10b between the pair of push plates above the second treatment tank 21, and while maintaining this state, lowers the pair of push plates downward into the second treatment tank 21, and then moves the pair of push plates closer to each other. Thereby, the used absorbent article 10b can be compressed and dehydrated.

[0060] Here, the first treatment tank 11 and the second treatment tank 21 may be the same. Further, the clamping part and the compression part may be the same. Thereby, inactivation (dehydration) of the superabsorbent polymer of the used absorbent article 10a and removal of dirt and foreign matters of the used absorbent article 10b can be performed in a space-saving and efficient manner. In particular, when the first treatment tank 11 and the second treatment tank 21 are the same and the clamping part and the compression part are the same, the effect is remarkable. In that case, in the tank that functions as the same treatment tank, the first aqueous solution L1 is filled during the immersion step S2, and the first aqueous solution L1 is removed during the dehydration step S3, or the liquid level of the first aqueous solution L1 is set to a height that does not contact the used absorbent article to be compressed. In that case, the pretreatment device A can be made into a compact device, and such a device can be installed in hospitals, nursing facilities, homes, etc. And before transporting the used absorbent article 10a to a treatment facility having the treatment device 50, by treating it by the above pretreatment method in a hospital, a nursing facility, a home, etc., the weight and volume of the used absorbent article 10c to be transported can be reduced.

[0061] In this pretreatment method (and pretreatment device), as a preferred embodiment, since the clamping part includes a pusher device, in the immersion step S2, the used absorbent article 10a is clamped and immersed in the first aqueous solution L1, and while being pushed step by step in the first aqueous solution L1, it can be relatively moved in the first treatment tank 11. Thereby, the superabsorbent polymer can be inactivated (dehydrated) more easily, and the excrement and dirt of the used absorbent article 10a can be more easily discharged into the first aqueous solution.

[0062] In this pretreatment method (and pretreatment apparatus), as a preferred embodiment, since the compression unit includes a pusher device, in the dehydration step S3, the used absorbent article 10b can be pushed step by step while being compressed, that is, moved relative to the second treatment tank 21. Thereby, dirt and foreign matters of the used absorbent article 10b can be more easily discharged to the outside and removed.

[0063] Note that the pretreatment apparatus A may also be arranged in the treatment facility equipped with the treatment apparatus 50, the pretreatment method may be carried out in the treatment facility, and the treatment step S50 may be continuously carried out in the treatment facility as it is. Alternatively, the pretreatment apparatus A may be arranged in a hospital, a nursing facility, a home, etc., the pretreatment method may be carried out individually in a hospital, a nursing facility, a home, etc., and then the treatment step S50 may be carried out separately in the treatment facility.

[0064] The pretreatment apparatus and pretreatment method of the present invention are not limited to the above-described embodiments, and can be appropriately changed or combined with known techniques within the scope not departing from the object and gist of the present invention.

Explanation of Reference Numerals

[0065] 10a Used absorbent article 11 First treatment tank 12 Clamping part L1 First aqueous solution S2 Immersion step

Claims

1. A pretreatment method for removing dirt and absorbed moisture attached to a used absorbent article containing a superabsorbent polymer, comprising: A bag-breaking step of taking out a plurality of the used absorbent articles from a collection bag containing the plurality of used absorbent articles by breaking the collection bag with a bag-breaking part which is a device, without destroying the plurality of used absorbent articles; An immersion step of immersing the used absorbent article taken out from the collection bag broken without destroying the used absorbent article in a first aqueous solution containing an inactivator in a first treatment tank while clamping the used absorbent article with a clamping part, and performing removal of dirt attached to the used absorbent article and inactivation of the superabsorbent polymer inside the used absorbent article without destroying the used absorbent article. The bag-breaking part includes a bag-breaking blade for making a cut of a predetermined size in the collection bag, and a discharge part for individually discharging the used absorbent article from the cut of the collection bag. The pretreatment method.

2. After the immersion step, the method further comprises a dehydration step of compressing and dehydrating the used absorbent article with a compression part in a second treatment tank. The pretreatment method according to Claim 1.

3. The first treatment tank and the second treatment tank are the same. The pretreatment method according to Claim 2.

4. After the dehydration step, the method further comprises a reuse step of transferring the drainage discharged from the used absorbent article and stored in the second treatment tank to the first treatment tank as part or all of the first aqueous solution in the immersion step. The pretreatment method according to Claim 2 or 3.

5. The dehydration step includes a step of compressing and dehydrating the used absorbent article with the compression part and relatively moving the used absorbent article with respect to the second treatment tank. The pretreatment method according to any one of Claims 2 to 4.

6. The compression part includes a roll press device. The pretreatment method according to any one of Claims 2 to 5.

7. The compression part includes a compression pusher device. The pretreatment method according to any one of Claims 2 to 5.

8. The immersion step includes a step of immersing the clamped used absorbent article in the first aqueous solution with the clamping part and relatively moving the used absorbent article with respect to the first treatment tank. The pretreatment method according to any one of Claims 1 to 7.

9. The clamping part includes a pair of conveying conveyors. The pretreatment method according to any one of Claims 1 to 8.

10. The clamping part is provided with a clamping pusher device. The pretreatment method according to any one of Claims 1 to 8.

11. A pretreatment device for removing dirt and absorbed moisture attached to a used absorbent article containing a superabsorbent polymer, a bag-breaking part which is a device for removing a plurality of used absorbent articles from a collection bag by breaking the collection bag containing the plurality of used absorbent articles without destroying the plurality of used absorbent articles, a first treatment tank having a first aqueous solution containing an inactivator, a clamping part for clamping the plurality of used absorbent articles, comprising: The bag-breaking part includes a bag-breaking blade for making a cut of a predetermined size in the collection bag, and a discharging part for individually discharging the used absorbent articles from the cut of the collection bag. In the bag-breaking part, the plurality of used absorbent articles taken out from the collection bag that has been bag-broken without destroying the used absorbent articles are clamped by the clamping part and immersed in the first aqueous solution in the first treatment tank, and the dirt attached to the used absorbent articles is removed and the superabsorbent polymer inside the used absorbent articles is inactivated without destroying the used absorbent articles. It is configured as follows. Pretreatment device.

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