JP7234054B2 - Recycled molded article and method for manufacturing recycled molded article - Google Patents

Description

TECHNICAL FIELD The present invention relates to a recycled molded article obtained from sheet pieces collected from used absorbent articles, and a method for producing the same.

Conventionally, solidified fuel (RPF) made from waste-derived paper, plastic, or the like has been known. RPF can be suitably used for thermal recycling, which is a recycling method for recovering and utilizing thermal energy generated during incineration.
Patent Document 1 discloses an excrement treatment material for treating excrement, which is provided with granular parts formed into granules. It describes an excrement treating material having an ash content of 5% or less, an ash content of 10% or less, and a total chlorine content of 2% or less. The higher calorific value (high calorific value) is the total calorific value, and Patent Document 1 states that the excreta disposal material of Patent Document 1 has a quality of RPF grade C or higher as defined in JIS Z 7302-2. It is described to have

Techniques are also known for recycling used absorbent articles. For example, Patent Document 2 discloses a used absorbent article comprising a topsheet, a backsheet, and an absorbent body containing an absorbent material, wherein at least one of the topsheet and the backsheet includes a film as a constituent member. , a method of recovering said components and producing a recycled product is described.

JP 2014-103864 A Japanese Unexamined Patent Application Publication No. 2018-171780

In recent years, it has been desired to reduce CO ₂ and garbage generated in disposal of absorbent article waste, and to add value to the waste by reusing the waste.
However, since used absorbent articles often contain excrement, it is difficult to efficiently remove the topsheet or backsheet itself or sheet pieces derived from the topsheet or backsheet from the absorbent article. , and it was difficult to manufacture an RPF using sheet pieces collected from used absorbent articles.

In the method described in Patent Document 2, when separating a used absorbent article into a film and an absorbent material, the used absorbent article is swollen with water, and then the absorbent article is subjected to a physical impact. is crushed into the film and the absorbent material by applying , then the film and the absorbent material are separated. Then, after separating the separated film into a plurality of types of recycling films according to the filler content, the recycling films are used to form a plurality of types of recycled resin pellets according to the filler content. there is

However, in the method described in Patent Document 2, in the step of separating the film and the absorbent material, in order to inactivate the superabsorbent polymer, the film and the absorbent material are soaked in an aqueous solution containing an inactivating agent. Alternatively, in order to remove the adhesive from the joint between the film and other member, the film is immersed in a solvent that dissolves the adhesive at the joint. Then, the film is dried to remove the aqueous solution containing the deactivator and the solvent that removes the adhesive. Therefore, in the method described in Patent Document 2, there is a risk that the solute of the solvent that removes the deactivator and the adhesive may remain in the separated film, and the formed recycled resin pellets are not suitable for the deactivator and the adhesive. May contain solvent solutes that remove agents. Therefore, the recycled resin pellets formed by the method described in Patent Document 2 contain the solute of the solvent that removes the deactivator and the adhesive, thereby satisfying the RPF quality specified in JIS Z 7302-2. there is a risk that it will not.
The present inventors have found that a high-quality recycled molded article can be obtained from the constituent materials of used absorbent articles, and have arrived at the present invention.

SUMMARY OF THE INVENTION An object of the present invention is to provide a recycled molded article that can overcome the above-described drawbacks of the prior art.

The present invention relates to a recycled molded article obtained from sheet pieces collected from used absorbent articles, which has a moisture content of 5% by mass or less, an ash content of 10% by mass or less, and a total chlorine content. The above object has been achieved by providing a recycled molded product having a calorific value of 0.3% by mass or less and a total calorific value of 25 MJ/kg or more as measured according to JIS Z 7302-2.

The present invention relates to a recycled molded article obtained from sheet pieces collected from used absorbent articles, which has a moisture content of 3% by mass or less, an ash content of 5% by mass or less, and a total chlorine content. The above object has been achieved by providing a recycled molded article having a rate of 0.6% by mass or less and a total calorific value of 33 MJ/kg or more as measured according to JIS Z 7302-2.

The present invention provides a method for manufacturing the recycled molded article described above, comprising a step of collecting sheet pieces from used absorbent articles, and forming the collected sheet pieces into a recycled molded article. The above object has been achieved by providing a method for producing a recycled molded product, comprising the steps of:

ADVANTAGE OF THE INVENTION According to this invention, the recycling molded object which can be used suitably for thermal recycling can be provided.

FIG. 1 is a perspective view showing an example of an absorbent article used in the method for producing a recycled molded article of the present invention. FIGS. 2(a) to 2(e) are conceptual diagrams showing one embodiment of the method for producing a recycled molded article of the present invention.

The recycled molded article of the present invention is a recycled molded article obtained from sheet pieces collected from used absorbent articles. The recycled molded article of the present invention can be produced, for example, as follows. First, the used absorbent article is frozen and then crushed to obtain crushed absorbent articles. Then, sheet pieces are recovered from the crushed material, and the sheet pieces are molded to produce recycled moldings. The recycled molded article of the present invention is produced, for example, as described above, and satisfies at least one of the following conditions (1) and (2), so that it can be suitably used for thermal recycling. It has become.

Condition (1) Moisture content is 5% by mass or less, ash content is 10% by mass or less, total chlorine content is 0.3% by mass or less, and is measured according to JIS Z 7302-2. Total calorific value is 25 MJ/kg or more.
Condition (2) Moisture content of 3% by mass or less, ash content of 5% by mass or less, total chlorine content of 0.6% by mass or less, and measured according to JIS Z 7302-2 Total calorific value is 33 MJ/kg or more.
The moisture content, ash content, and total chlorine content are measured according to JIS Z 7302-3, JIS Z 7302-4, and JIS Z 7302-6, respectively.

The recycled molded article of the present invention satisfies at least one of the conditions (1) and (2), and preferably satisfies both the conditions (1) and (2). Hereinafter, the recycled molded body satisfying the condition (1) is also referred to as a recycled molded body 10A, and the recycled molded body satisfying the condition (2) is also referred to as a recycled molded body 10B.
A preferred configuration common to the recycled molded bodies 10A and 10B will be described by taking the recycled molded body 10 satisfying both the conditions (1) and (2) as an example.

As described above, the recycled molded article 10 is obtained by molding sheet pieces collected from used absorbent articles. Absorbent articles are mainly used to absorb and retain bodily fluids excreted from the body, such as urine, menstrual blood, and vaginal discharge. A used absorbent article means an absorbent article after absorbing excrement such as urine excreted by a wearer, and water is contained in the absorbent article, particularly in the absorbent core. Examples of excrement include feces and the like in addition to bodily fluids excreted from the body. Absorbent articles include, for example, disposable diapers, sanitary napkins, incontinence pads, panty liners, etc., but are not limited to these, and broadly include articles used to absorb fluid discharged from the human body. do. Absorbent articles typically comprise a liquid-permeable topsheet, a liquid-impermeable or water-repellent backsheet, and a liquid-retentive absorbent core interposed between the two sheets. The absorbent article may further comprise various members according to its specific use. Such members are known to those skilled in the art.

In the present invention, the absorbent article used for collecting the sheet pieces may be a single absorbent article, but preferably a plurality of absorbent articles. FIG. 1 shows an absorbent article 1, which is an example of an absorbent article. The absorbent article 1 is a used absorbent article. As the absorbent article 1, for example, used absorbent articles discarded by care facilities, nursery facilities, and households can be used. The absorbent article 1 includes an absorbent body 4 having absorbent material, a topsheet 2 and a backsheet 3 . The absorbent body 4 is interposed between the top sheet 2 and the back sheet 3, and the top sheet 2 and the back sheet 3 are bonded together at their peripheries with an adhesive or the like. Examples of adhesives include hot-melt adhesives.

The absorbent article 1 is a so-called unfolded disposable diaper, and has a crotch portion A in the central portion in the longitudinal direction. A certain dorsal part B has fastening tapes 5 on both side edges, and fastening tapes 5 are provided on the non-skin facing surface of the other abdominal part C (the surface facing away from the wearer's skin when worn). A landing zone 6 is provided for fixing the tape 5 .
In the present invention, the absorbent article may be a so-called pants-type diaper. Pants-type diapers typically have a crotch part in the central part in the longitudinal direction, and both sides of the dorsal part, which is one part of both parts extending in the front and rear of the crotch part, and the crotch part. , and both sides of the abdomen, which is the other part, are joined together to form a pair of side seals, a waist opening through which the torso of the wearer is passed, and a pair of legs through which the lower legs of the wearer are passed. An opening is formed.
Also, in the present invention, the absorbent article may be a so-called napkin, pad, or panty liner. A napkin typically has a crotch portion in the central portion in the longitudinal direction, and a dorsal portion extending from the front and back of the crotch portion and an abdominal portion, which is the other portion, are formed.

The topsheet 2, backsheet 3, absorbent body 4 and other constituent materials include those used in conventional absorbent articles. As the surface sheet 2 and the back sheet 3, a nonwoven fabric, a sheet material, or the like made of a synthetic resin such as a thermoplastic resin is used. Examples of thermoplastic resins include polyolefins such as polyethylene and polypropylene; polyesters such as polyethylene terephthalate; polyamides such as nylon 6 and nylon 66. These may be used alone or in combination of two or more. . As the absorbent body 4, an absorbent material wrapped with tissue paper or the like can be used.

Absorbent materials forming the absorbent body 4 include various absorbent materials conventionally used in absorbent bodies for absorbent articles, and are not particularly limited. Absorbent materials include, for example, cellulosic fibers, synthetic fibers that have been hydrophilized, fibrous materials such as synthetic fibers that have not been hydrophilized, and superabsorbent polymers. Cellulosic fibers include wood pulp fibers, rayon fibers, cotton fibers, cellulose acetate fibers, and the like. Examples of synthetic fiber materials include polyolefins such as polyethylene (PE) and polypropylene (PP); polyesters such as polyethylene terephthalate (PET); polyamides such as nylon 6 and nylon 66; Polyvinyl chloride, polyvinylidene chloride and the like can be mentioned, and one of these can be used alone or two or more of them can be used in combination. Polymers or copolymers of acrylic acid or alkali metal salts of acrylic acid can generally be used as the superabsorbent polymer.

In addition, in the unfolded absorbent article 1 shown in FIG. The fastening tapes 5 are fixed to the side flap portions 11 on both sides of the back portion B in the width direction. The side flap portions 11 are portions extending outward in the diaper width direction from both side edges of the absorbent body 4 , and are composed of a laminate of a sheet for forming the three-dimensional gathers 7 and the backsheet 3 .

Sheet pieces 8 recovered from the absorbent article 1 include sheet pieces 8 derived from the top sheet 2 or the back sheet 3 . The sheet piece 8 may be a sheet piece produced by crushing the top sheet 2 or the back sheet 3, or may be the top sheet 2 or the back sheet 3 itself that maintains its original shape.

The recycled molded body 10 has a quality of grade A or higher for a solidified fuel (RPF: Refused paper and plastics densified fuel) defined in JIS Z 7311. RFPs are classified as shown in Table 1 according to total calorific value, moisture content, ash content and total chlorine content.

The total calorific value of the recycled compact 10 is 25 MJ/kg or more, which is about the same as that of lignite, from the viewpoint of improving the performance of fuel and expanding the application, and is preferably used in power boilers and industrial boilers. It is 30 MJ/kg or more, which is about the calorific value of sub-bituminous coal that can be used for steaming coal, and more preferably 33 MJ/kg, which is about the calorific value of coking coal bituminous coal (class C) that can be used for ironmaking (coke). kg or more, and more preferably 35 MJ/kg or more, which is about the calorific value of bituminous coal (class B). It is preferable that the total calorific value of the recycled compact 10 is as large as possible from the viewpoint of improving the performance of the fuel and expanding the applications of use.

The moisture content of the recycled molded body 10 is 5% by mass or less, preferably 3% by mass, from the viewpoint of enhancing ignitability, enhancing the thermal efficiency of boilers, engines, turbines, etc., and enhancing the durability of furnaces. It is below. The moisture content of the recycled molded body 10 is preferably as small as possible from the viewpoint of enhancing ignitability, enhancing the thermal efficiency of boilers, engines, turbines, etc., and enhancing the durability of furnaces, and the lower limit is not particularly limited. , for example, 0.001% by mass or more.

The ash content of the recycled molded body 10 is 10 from the viewpoint of improving ignitability, improving thermal efficiency of boilers, engines, turbines, etc., improving furnace durability, and reducing the number and time of maintenance of the furnace. % by mass or less, preferably 5% by mass or less. The ash content of the recycled molded body 10 is small from the viewpoint of improving ignitability, improving thermal efficiency of boilers, engines, turbines, etc., improving furnace durability, and reducing the frequency and time of maintenance of the furnace. Although the lower limit is not particularly limited, it can be, for example, 0.001% by mass or more.

The total chlorine content of the recycled molded body 10 suppresses corrosion of boilers, engines, turbines, furnaces, etc., increases the durability of furnaces, and reduces the risk of generating harmful substances such as dioxins generated during low-temperature combustion. Therefore, it is 0.6% by mass or less, preferably 0.3% by mass or less. The total chlorine content of the recycled molded body 10 suppresses corrosion of boilers, engines, turbines, furnaces, etc., increases the durability of furnaces, and reduces the risk of generating harmful substances such as dioxins generated during low-temperature combustion. Therefore, the smaller the content, the better, and although there is no particular lower limit, it can be, for example, 0.0001% by mass or more.

The recycled molded article according to the present invention is formed using sheet pieces separated from used absorbent articles, and the sheet pieces such as the top sheet or the back sheet used for absorbent articles have a high total calorific value. , the content of water, ash, and chlorine is low, so the condition (1) or (2) can be easily satisfied. In order to easily satisfy the condition (1) or (2), it is also possible to select absorbent articles of a specific type or in a specific state of use and use them as raw materials for recycled molded articles. In addition, in order to easily satisfy the condition (1) or (2), a sheet piece of a specific type or in a specific state is selected from the sheet pieces separated from the used absorbent article, and the raw material for the recycled molded product is obtained. It can also be used as

In order to increase the total calorific value of the recycled molded article, it is preferable to use, as a raw material, an absorbent article using a resin having a high total calorific value as the whole or a part of the absorbent article used as the raw material. Resins having a high total calorific value are synthetic resins, particularly polyolefins such as polyethylene and polypropylene.

In order to reduce the moisture content of the recycled molded article, it is preferable to use, as a raw material, an absorbent article using a hydrophobic resin as the whole or a part of the absorbent article used as the raw material. Hydrophobic resins are synthetic resins, particularly polyolefins such as polyethylene and polypropylene; and polyesters such as polyethylene terephthalate.

In order to reduce the ash content of the recycled molded product, it is possible to use absorbent articles with little adhesion and/or content of inorganic substances that become ash as the whole or part of the absorbent articles used as raw materials. preferable. Absorbent articles with little adhesion of inorganic substances include, for example, absorbent articles with little adhesion of urine or dried urine containing sodium, calcium, magnesium, and potassium as inorganic substances, and absorbent articles containing a large amount of sodium, calcium, magnesium, and potassium as inorganic substances. Examples include an aqueous solution containing an inactivating agent used for inactivating the superabsorbent polymer and an absorbent article to which the inactivating agent is less attached. Absorbent articles containing little inorganic matter include, for example, absorbent articles made of a resin material containing little inorganic matter (inorganic filler) and absorbent articles that absorb little inorganic matter. As a resin material containing less inorganic substances, for example, a synthetic resin nonwoven fabric made of semidull fibers is preferable to a synthetic resin nonwoven fabric made of full dull fibers, and a film containing no calcium carbonate is more preferable than a film containing calcium carbonate. Examples of absorbent articles that absorb little inorganic matter include urine containing sodium, calcium, magnesium, and potassium as inorganic matter, and an inactivating superabsorbent polymer that contains a large amount of sodium, calcium, magnesium, and potassium as inorganic matter. Absorbent articles having low absorption of aqueous solutions containing active agents are included.

In addition, in order to reduce the chlorine content of the recycled molded product, as a whole or part of the absorbent article used as a raw material, an absorbent article with less adhesion and content of chloride, which becomes chlorine, is used as a raw material. It is preferable to use Absorbent articles with little chloride adhesion include, for example, absorbent articles with little adhesion of urine and dried urine containing sodium chloride, calcium chloride, magnesium chloride, and potassium chloride as inorganic chlorides, and sodium chloride as inorganic chlorides. Aqueous solutions containing inactivating agents used to inactivate superabsorbent polymers containing a large amount of calcium chloride, magnesium chloride, and potassium chloride, absorbent articles with little adhesion of inactivating agents, gloves and gloves made of vinyl chloride as an organic chloride Absorbent articles with less contamination of debris. Examples of absorbent articles containing less inorganic chlorides and organic chlorides include absorbent articles containing less urine absorption containing sodium chloride, calcium chloride, magnesium chloride, and potassium chloride as inorganic chlorides, and absorbent articles containing less inorganic chlorides. Absorbent articles with low absorption of aqueous solutions containing deactivators used to deactivate superabsorbent polymers containing a large amount of sodium chloride, calcium chloride, magnesium chloride, and potassium chloride, and vinyl chloride is not used as an organic chloride. Absorbent articles are included.

In order to increase the total calorific value of the recycled molded article, it is preferable to use, as a raw material, a sheet piece using a resin having a high total calorific value as the whole or a part of the sheet piece used as the raw material.
In order to reduce the moisture content of the recycled molded product, it is preferable to use, as a raw material, a sheet piece using a hydrophobic resin as the whole or a part of the sheet piece used as the raw material.

In order to reduce the ash content of the recycled molded product, it is preferable to use, as a raw material, a sheet piece with little adhesion and/or content of inorganic matter that becomes ash, as the whole or part of the sheet piece used as the raw material. Examples of sheet pieces to which inorganic substances are less adhered include, for example, sheet pieces to which urine containing sodium, calcium, magnesium, and potassium as inorganic substances and dried urine substances are less adhered, and highly absorbent sheet pieces containing a large amount of sodium, calcium, magnesium, and potassium as inorganic substances. Examples include an aqueous solution containing an inactivating agent used for inactivating the polymer and a sheet piece to which the inactivating agent is less attached. Sheet pieces containing less inorganic matter include, for example, sheet pieces made of a resin material containing less inorganic matter (inorganic filler). As a resin material containing less inorganic substances, for example, a synthetic resin nonwoven fabric made of semidull fibers is preferable to a synthetic resin nonwoven fabric made of full dull fibers, and a film containing no calcium carbonate is more preferable than a film containing calcium carbonate.

In addition, in order to reduce the chlorine content of the recycled molded product, it is necessary to use, as a raw material, a sheet piece with a low adhesion and content of chlorides, which is a chlorine content, as the whole or part of the sheet piece used as a raw material. is preferred. Examples of sheet pieces with little adhesion of chlorides include sheet pieces with little adhesion of urine or dried urine containing sodium chloride, calcium chloride, magnesium chloride, and potassium chloride as inorganic chlorides, and sodium chloride and chloride as inorganic chlorides. Aqueous solutions containing inactivating agents used to inactivate superabsorbent polymers containing a large amount of calcium, magnesium chloride, and potassium chloride, sheet pieces with little adhesion of inactivating agents, and fragments of vinyl chloride gloves as organic chlorides are mixed in. Fewer sheet pieces are mentioned. Examples of absorbent articles containing less inorganic chlorides and organic chlorides include sheet pieces that do not use vinyl chloride as organic chlorides.

[Recycled compact 10A]
The recycled molded product 10A satisfies the condition (1) and has a quality equal to or higher than RFP grade A defined in JIS Z 7311 (see Table 1). For this reason, the recycled compact 10A can be handled in the same way as steam coal, and can be used as a substitute for burning coal or oil, so that CO ₂ generation can be suppressed and it can be suitably used for thermal recycling. .

[Recycled compact 10B]
The recycled molded body 10B satisfies the condition (2), and has a quality equal to or higher than that of RFP-coke, which has a total calorific value (higher calorific value) comparable to that of coke, as defined in JIS Z 7311 (Table 1). For this reason, the recycled compact 10B can be handled in the same manner as thermal coal, and can be used as a substitute for burning coal or oil, so that CO ₂ generation can be suppressed and it can be suitably used for thermal recycling. .

In addition, the recycled molded body 10B can be treated in the same manner as coking coal, and can be used as a substitute for coal _or petroleum as a raw material. It's becoming This point will be described in detail. Methods of chemical recycling include, for example, blast furnace raw material conversion, coke oven chemical raw material conversion, gasification, oil conversion, raw material/monomer conversion, and the like.
Blast furnace raw material is a technology that uses waste plastic as a reducing agent for iron ore instead of coke or pulverized coal in a blast furnace. As described above, the recycled compact 10B has a total calorific value comparable to that of coke, and has a high ratio of carbon and hydrogen, so that it can be suitably used as a reducing agent in blast furnace raw material conversion.
In the coke oven chemical raw material, waste plastic is thermally decomposed under pressure at a high temperature (600°C to 1300°C) to produce coke as a reducing agent for blast furnaces, hydrocarbon oil as a chemical raw material, and coke ovens used for power generation. It is a technique to obtain gas. As described above, the recycled compact 10B has a total calorific value comparable to that of coke, and has a high ratio of carbon and hydrogen.

Gasification is a technology for recovering waste plastics by heating them with a limited amount of oxygen to convert them into gases of hydrocarbons, carbon monoxide and hydrogen. The recovered hydrocarbons, carbon monoxide and hydrogen are used as raw materials for chemical industries such as methanol, ammonia and acetic acid. As described above, the recycled compact 10B has a total calorific value comparable to that of coke, and since it has a high ratio of carbon and hydrogen, it can be efficiently gasified.
Oilification is a technology of completely pyrolyzing waste plastics using a reforming catalyst at about 400° C. to obtain hydrocarbon oil. In liquefaction, it is important to remove chlorine from waste plastics. Since the recycled compact 10B has a total chlorine content of 0.6% by mass or less, it can be suitably used for conversion to oil.
Raw material/monomerization is a technology that thermally decomposes and/or chemically decomposes waste plastics, returns them to raw materials and monomers, and makes plastic products again. As described above, the recycled compact 10B has a total calorific value comparable to that of coke, and has a high ratio of carbon and hydrogen, so that it can be suitably used as a raw material/monomer.

A preferred configuration of the recycled molded bodies 10A and 10B will be further described.
Examples of the recycled compact 10 include fluff fuel, bale packages, pellets, etc. Among these, pellets that can have a high specific gravity and are suitable for transportation are preferable. When the recycled molded body 10 is a pellet, the recycled molded body 10 has a large specific surface area, an increased reaction area for reduction, combustion, etc., so that it can be used more preferably as a reducing agent or fuel. , preferably porous.

Next, a preferred embodiment of the method for producing a recycled molded article of the present invention will be described with reference to the drawings. FIG. 2 shows an outline of a method for manufacturing the above-described recycled molded article 10 as a first embodiment of the method for manufacturing a recycled molded article of the present invention.
The manufacturing method of the first embodiment shown in FIG. and a step of molding into the body 10 (see FIG. 2(e)). In the first embodiment, an aggregate of a plurality of absorbent articles 1 is used as a used absorbent article (see FIG. 2(a)). As described above, the absorbent article used in the manufacturing method of the first embodiment has a plurality of different shapes such as a developed type and a pants type, a state such as used or unused, a size, etc. It may be an aggregate of absorbent articles. That is, the manufacturing method of the first embodiment can be applied to a single type of absorbent article, but mixed absorbent articles collected from nursing care facilities or large-scale collections from homes It can also be applied to objects.

The process of recovering the sheet pieces 8 from the used absorbent article 1 comprises a freezing process, a crushing process and a separating process in this order.
In the freezing step, water in the absorbent article 1 is frozen (see FIG. 2(b)). The freezing step is performed to facilitate crushing of the absorbent article 1, particularly the absorbent body 4, in the subsequent crushing step. By freezing the moisture in the absorbent article 1 in the freezing step, it is possible to reduce the impact strength of the moisture-containing portion of the absorbent article 1, particularly the absorbent body 4, compared to before freezing. When an impact is applied in the crushing process, the portion containing moisture in the absorbent article 1, particularly the absorbent body 4, can be easily crushed. Since the absorbent article 1 has been used, the absorbent body 4 contains more moisture than the top sheet 2 and the back sheet 3 . Therefore, when the moisture in the absorbent article 1 is frozen, the impact strength of the top sheet 2 and the back sheet 3 does not decrease so much, but the impact strength of the absorber 4 decreases significantly. In the absorbent article 1 that has undergone the freezing process, the impact strength of the absorbent body 4 is lower than that of the top sheet 2 and the back sheet 3, making it easier to break into smaller pieces.

The freezing step can be performed by placing the absorbent article 1 under low temperature conditions. A low temperature condition means a condition under which water in the absorbent article 1 can be frozen. For example, it is 0° C. or less at 1 atmosphere. Since body fluid excreted from the body, such as urine absorbed by the absorbent article 1, contains salts, the freezing step is preferably carried out at -5°C from the viewpoint of reliably freezing the moisture in the absorbent article 1. Thereafter, the temperature is preferably −10° C. or lower, more preferably −20° C. or lower.

Even when the absorbent article 1 does not contain moisture, depending on the type of adhesive bonding the topsheet 2 and the backsheet 3, the adhesive strength of the adhesive may be reduced by cooling in the freezing step. may decrease. Such adhesives include, for example, hot-melt adhesives that are melted by heating. Hot melt adhesives typically contain a base polymer, a tackifier and a plasticizer. Specific examples of base polymers include acrylic, silicone, rubber, and olefin polymers. Examples of the acrylic polymer include vinyl monomer (co)polymers (ethylene-vinyl acetate copolymers) containing 2-ethylhexyl acrylate, butyl acrylate, ethyl acrylate, cyanoacrylate, vinyl acetate, methyl methacrylate, etc. as main components. coalescence, etc.) can be exemplified. Examples of the silicone-based polymer include polydimethylsiloxane polymer. Examples of the rubber-based polymer include natural rubber, polyisoprene, styrene-butadiene copolymer (SBR), styrene-isoprene-styrene block copolymer (SIS), styrene-butadiene-styrene block copolymer (SBS ), styrene-ethylene-butadiene-styrene block copolymer (SEBS), and styrene-ethylene-propylene-styrene block copolymer (SEPS). As the adhesive strength of the adhesive decreases, the top sheet 2 and the back sheet 3 are easily separated from each other when an impact is applied in the crushing process, and the joints between the two sheets 2 and 3 are peeled off. , 3, the absorbent body 4 can easily be taken out.

In the crushing step, impact is applied to the absorbent article 1 to crush the absorbent article 1 (see FIG. 2(c)). The crushing step is performed to crush the absorbent article 1 and obtain a crushed mixture in which the constituent materials of the absorbent article 1 and their small pieces are mixed. The crushed mixture contains sheet pieces 8 derived from the topsheet 2 or backsheet 3, lumps 9 of absorbent material derived from the absorbent body 4, and the like. In the first embodiment, the mass 9 of absorbent material originating from the absorbent body 4 contains excrement.

The crushing step can be performed using, for example, a so-called crusher or grinder. Examples of crushers and crushers include compression crushers, impact crushers, grinding crushers, shear crushers, and devices combining these. A compression crusher is a device that crushes an object by compressing it, and includes, for example, a jaw crusher, a gyratory crusher, a cone crusher, a roll crusher, and the like. The impact crusher is a device that crushes an object by impacting it with a hammer, impact plate, or the like. etc. A grinding-type crusher is a device that crushes an object by grinding it. , a bead mill, and the like. A shear-type crusher is a device that crushes an object by shearing it, and examples thereof include a cutter mill, a single-screw crusher, and a twin-screw crusher.

In the absorbent article 1 that has undergone the freezing process, the absorbent core 4 is particularly susceptible to cracking, so in the crushing process, the absorbent core 4 is crushed into smaller pieces than the top sheet 2 and the back sheet 3. be. Therefore, the lumps 9 of absorbent material produced by crushing the absorbent body 4 are smaller than the sheet pieces 8 produced by crushing the topsheet 2 or the backsheet 3 .
The sheet piece 8 derived from the top sheet 2 or the back sheet 3 obtained after the crushing process has a mesh opening of a size that cannot pass through a 2 mm sieve, which is the standard length of pulp contained in the absorbent body. is preferred, and in order to improve the separation speed in the subsequent separation step, it is more preferably a size that cannot pass through a 5 mm sieve, more preferably a size that cannot pass through a 10 mm sieve, and further Even more preferably, the size is such that it cannot pass through a 20 mm sieve.
The mass 9 of the absorbent material obtained after the crushing step preferably has a size that allows it to pass through a sieve with an opening of 2 mm, more preferably a size that allows it to pass through a sieve with an opening of 5 mm. It is more preferable to have a size that can pass through a sieve of 20 mm, and even more preferably a size that can pass through a 20 mm sieve.

In the first embodiment, it is preferable that the absorbent material can be taken out from between the top sheet 2 and the back sheet 3 in the crushing step. Generally, in the absorbent article 1, the absorbent body 4 is interposed between the top sheet 2 and the back sheet 3 which are joined together at their peripheral edges. Therefore, even if an impact is applied to the absorbent article 1 and the absorber 4 is finely crushed, the top sheet 2 and the back sheet 3 are not broken, and the bonding between the top sheet 2 and the back sheet 3 is maintained. If so, the space between the top sheet 2 and the back sheet 3 remains sealed and the absorbent material cannot be removed from between the sheets 2, 3, and in the subsequent separation process, both sheets 2, 3 are separated. 3 and the absorbent material cannot be separated. Therefore, in the crushing step, the absorbent material is removed from between the topsheet 2 and the backsheet 3 by breaking the topsheet 2 or the backsheet 3 or destroying the bonding between the topsheet 2 and the backsheet 3. It is preferable to put it in a state in which it can be taken out.

In the separation step, sheet pieces 8 originating from the topsheet 2 or the backsheet 3 and the absorbent material are separated from the crushed mixture obtained in the crushing step (see FIG. 2(d)). The separation step is performed so that the sheet pieces 8 originating from the topsheet 2 or the backsheet 3 and the absorbent material can be collected separately. In the first embodiment, since the sheet piece 8 derived from the top sheet 2 or the back sheet 3 and the lump 9 of the absorbent material are different in size, the method for separating the two is to separate them according to their size. method can be used. In a first embodiment, the crushed mixture is sieved to separate the sheet pieces 8 and the absorbent material. The size of the mesh of the sieve can be appropriately selected according to the sizes of the sheet pieces 8 and the masses 9 of the absorbent material contained in the crushed mixture.

In the first embodiment, the sheet pieces 8 derived from the topsheet 2 or the backsheet 3 and the absorbent material separated in the separation step are recovered. Here, collecting means, for example, storing the separated sheet piece 8 and absorbent material in containers at separate locations or moving them to separate locations. Various known methods can be used as the method for collecting the sheet pieces 8 and the method for collecting the absorbent material. For example, the sheet piece 8 and the absorbent material may each be housed in a container. Further, for example, in the separation step, a belt conveyor or the like is arranged under the sieve, and after separating the sheet pieces 8 on the sieve and the absorbent material on the belt conveyor, the belt conveyor is driven to Absorbent materials and the like collected on the belt conveyor may be moved to another location.

Next, a moisture reduction step is performed to reduce the moisture content of the collected sheet pieces 8 . Examples of the water content reduction process include a drying process for drying the sheet piece 8 and a dehydration process for dehydrating the sheet piece 8 . The method of drying the sheet piece 8 in the drying step is not particularly limited, and examples include contact with a heating structure (heating element), air drying with normal temperature air, spraying or air drying with heated air or steam (superheated steam), vacuum drying, Examples thereof include electromagnetic wave heating and electric heating. A method for dewatering the sheet piece 8 in the dehydration step is not particularly limited, and examples thereof include vacuum dehydration, centrifugal dehydration, pressurized dehydration, and belt press dehydration. The water content reduction process is not particularly limited to the drying process alone, the dehydration process alone, or the combination of the dehydration process and the drying process, but from the viewpoint of reducing the amount of CO ₂ generated in the process, it is preferable to select an energy-saving process. .

In the case of manufacturing the recycled molded body 10A, if the water content of the collected sheet pieces 8 exceeds 5% by mass, the water content of the sheet pieces 8 becomes 5% by mass or less in the water content reduction step. Reduce the moisture content to When the recycled molded body 10B is produced, if the moisture content of the collected sheet pieces 8 exceeds 3% by mass, the moisture content of the sheet pieces 8 becomes 3% by mass or less in the moisture content reduction step. Reduce the moisture content to

Then, a molding step is performed to mold the collected sheet pieces 8 into the recycled molding 10 (see FIG. 2(e)). The method of forming the sheet pieces 8 into the recycled compact 10 is not particularly limited, and examples include a method of forming the sheet pieces 8 into fluff fuel, a method of forming the sheet pieces 8 into a bale compact, and a method of forming the sheet pieces 8 into pellets. and the like. Moreover, the forming step may be accompanied by a step of heating the sheet piece 8 . When the molding process involves a heating process, the molding process may also serve as the drying process described above. Further, the molding step may be accompanied by a step of compressing the sheet piece 8 . When the molding process involves the compression process, the molding process may also serve as the above-described dehydration process. The molding process is not particularly limited, but from the viewpoint of reducing the amount of CO ₂ generated in the process, it is preferable to select an energy-saving process, and it is preferable to combine the drying process and / or dehydration process for energy saving.

As a method for forming the sheet piece 8 into the fluff fuel, a forming step combining either one or both of the drying step and the dehydration step is performed, and the sheet piece having a water content below a specified value, for example, 5% by mass or less. 8 is fluff combustion. The fluff fuel may be used directly on the spot, or may be put into a container and transported to be used at the destination.
As a method of forming the sheet piece 8 into a bale molded body, after compressing the sheet piece 8, the sheet piece 8 is packed with a stretch film, a band, a bale, or the like, and then molded into a bale molded body.
Methods for forming the sheet pieces 8 into pellets include a strand cut method, a die face cut method, a flat die method, a ring die method, a hot cut method, a screw method, and the like. In order to produce the porous pellets described above, from the viewpoint of making the most of the porosity of the nonwoven fabric structure contained in the sheet pieces, a molding process using a flat die method, ring die method, or screw method that does not apply too much heat is preferable. .

According to the manufacturing method of the first embodiment, the recycled molded bodies 10A and 10B are obtained as described above.
In the first embodiment, the freezing step reduces the impact strength of the absorbent body 4 to a greater extent than the impact strength of the sheet pieces 8 derived from the top sheet 2 and the back sheet 3 . Therefore, in the crushing process, when the absorbent article 1 is impacted, the absorber 4 is crushed into smaller pieces than the topsheet 2 and the backsheet 3 . Since lumps of absorbent material derived from the absorbent body 4 and sheet pieces 8 derived from the top sheet 2 or the back sheet 3 obtained after the crushing process are significantly different in size, the top sheet 2 and the back sheet 3 are different in size. can be separated from the absorbent material by a simple method such as sieving.
In addition, in the first embodiment, since the moisture in the absorbent body 4 is frozen, the absorbent material is less likely to adhere to the top sheet 2 and the back sheet 3 when the absorbent article 1 is crushed in the crushing process. It's becoming This makes it possible to prevent difficulty in separating the sheet pieces 8 originating from the top sheet 2 or the back sheet 3 and the absorbent material in the separation step.
As described above, according to the manufacturing method of the first embodiment, the sheet pieces 8 can be efficiently collected from the absorbent article 1, so that the recycled formed bodies 10A and 10B can be manufactured efficiently.

In addition, since the manufacturing method of the first embodiment does not require the absorbent article 1 to be intentionally soaked in water, it can be compared to a method having a step of swelling a used absorbent article with water, such as that disclosed in Patent Document 2. As a result, the drying process can be performed in a short time. In addition, since the manufacturing method of the first embodiment can easily separate the sheet piece 8 and the absorbent material as described above, for example, as in Patent Document 2, the process of inactivating the water-absorbing polymer , the number of treatment steps can be reduced, and since there is no need to use an inactivating agent containing a large amount of inorganic substances and chlorides, ash and chlorine content can be reduced.

Moreover, in the first embodiment, it is preferable to have a rough crushing step before the freezing step. The rough crushing step is a step of crushing the absorbent article 1 more roughly than the crushing step. The rough crushing step is performed to roughly crush the absorbent article 1 to increase the surface area of the absorbent body 4 and facilitate freezing of the absorbent body 4 . It is preferable that the rough crushing process takes a shorter treatment time than the crushing process and/or has a smaller impact on the absorbent article 1 than the crushing process. Like the crushing process, the rough crushing process can crush the absorbent article 1 by applying impact to the absorbent article 1 . The type of impact may be the same or different between the rough crushing process and the crushing process.

In the coarsely crushing step, it is preferable to create a state in which the absorbent material and excrement can be taken out from between the top sheet 2 and the back sheet 3 .
The sheet pieces derived from the top sheet 2 or the back sheet 3 obtained after the coarse crushing step preferably have a size that cannot pass through a sieve with an opening of 5 mm, and a size that cannot pass through a sieve with an opening of 10 mm. It is preferable that the mesh size is such that it cannot pass through a sieve with an opening of 20 mm.
The mass of the absorbent material obtained after the coarse crushing step preferably has a size that allows it to pass through a sieve with an opening of 5 mm, preferably a size that allows it to pass through a sieve with an opening of 10 mm. is of a size that can pass through a 20 mm sieve.

By performing the coarse crushing step before the freezing step, the surface area of the absorbent body 4 can be increased, and the water content in the absorbent body 4 can be easily frozen in the freezing step. Further, by coarsely crushing the absorbent article 1 in advance by the coarse crushing process, the time required for the crushing process can be shortened.

Further, in the first embodiment, it is preferable that the process after the freezing process, that is, either one or both of the crushing process and the separating process is performed at a temperature at which the moisture in the absorbent article 1 can be maintained in a frozen state. As a result, in the process after the freezing process, the absorbent material adheres to the top sheet 2, the back sheet 3, etc. through moisture, and the sheet pieces derived from the top sheet 2 or the back sheet 3 and the absorbent material are separated in the separation process. becomes difficult to separate. It is more preferable to perform both the crushing step and the separating step at a temperature at which the moisture in the absorbent article 1 can be maintained in a frozen state. The temperature at which the water in the absorbent article 1 can remain frozen is preferably 0° C. or lower, more preferably −5° C. or lower, still more preferably −10° C. or lower, at 1 atm. More preferably -20°C or lower.

Moreover, in the first embodiment, it is preferable to perform the separation step while vibrating the crushed mixture obtained by the crushing step. Specifically, it is preferable to separate the sheet pieces originating from the top sheet 2 or the back sheet 3 and the absorbent material while vibrating them. As a result, even if the crushed mixture forms lumps, the crushed mixture can be separated while being loosened, so that the sheet pieces and the absorbent material can be separated accurately. Also, by applying vibration, clumps of the absorbent material, which are easily crushed due to freezing of moisture, can be crushed into smaller pieces. Therefore, the sheet piece and the absorbent material can be separated from each other more easily because the size difference between the sheet pieces and the absorbent material can be increased.

Next, a second embodiment of the method for producing recycled molded articles of the present invention will be described. Regarding the second embodiment, only the differences from the first embodiment will be described. Points that are not specifically described for the second embodiment are the same as those for the first embodiment, and the description for the first embodiment applies accordingly.

In the manufacturing method of the second embodiment, the step of recovering the sheet pieces 8 from the used absorbent article 1 comprises a rough crushing step, a freezing step and a separating step in this order. The rough crushing step, freezing step and separation step can be performed in the same manner as the rough crushing step, freezing step and separation step in the first embodiment.

In the second embodiment, first, a coarse crushing step is performed to coarsely crush the absorbent article 1 . Next, a freezing step is performed to freeze water in the absorbent article 1 . Thereafter, a separation step is performed to separate and recover sheet pieces originating from the top sheet or the back sheet and the absorbent material. In the second embodiment, unlike the first embodiment, the freezing step is not followed by the crushing step.

In the second embodiment, the rough crushing step increases the surface area of the absorbent body 4, making it easier for the water in the absorbent body 4 to freeze. In addition, the freezing process freezes water in the absorbent body 4 , making it difficult for the absorbent material to adhere to the top sheet 2 and the back sheet 3 . Therefore, in the separation and recovery method of the second embodiment, as in the first embodiment, the sheet pieces derived from the top sheet 2 and the back sheet 3 and the absorbent material are subjected to a simple method such as sieving. can be separated and recovered by

In the second embodiment, it is preferable that the sheet piece and the absorbent material are separated while being vibrated in the separating step. As a result, the water content is frozen and the absorbent body 4 with reduced impact strength can be crushed into finer small pieces. can be greatly different, and the sheet piece and the absorbent material can be separated and collected more easily.

Next, an embodiment of a manufacturing apparatus for a recycled molded article that is suitably used in the manufacturing method of the first embodiment of the present invention will be described. The manufacturing apparatus of the present embodiment is a manufacturing apparatus capable of manufacturing the recycled molded article 10 described above. The manufacturing apparatus of the present embodiment includes a sheet piece collection unit that collects sheet pieces 8 from used absorbent articles 1 and a molding unit that molds the collected sheet pieces 8 into recycled moldings 10 .

In the manufacturing apparatus of the present embodiment, the sheet piece collecting section includes a freezing section, a crushing section, and a separating section for separating sheet pieces 8 derived from the top sheet 2 or the back sheet 3 from the absorbent material. Prepare in this order from upstream to downstream. Further, the manufacturing apparatus of the present embodiment preferably has a rough crushing section for roughly crushing the absorbent article 1 upstream of the freezing section. In addition, in the manufacturing apparatus of the present embodiment, each section may be independent, or may be connected and continuous by a conveying section such as a belt conveyor.

The freezing section is configured to freeze water in the absorbent article 1 . Specifically, the freezing section preferably includes a freezing device capable of performing the freezing step described above. Examples of the freezing device include a device for immersing in a liquid refrigerant, a device for contacting with a solid refrigerant, a device for blowing cold air, and a device combining these. As a device for immersing in a liquid refrigerant, for example, a brine refrigerator that freezes by immersing in a liquid refrigerant such as brine (salt solution, alcohol, etc.) or liquefied gas (liquid nitrogen, liquid carbon dioxide gas, etc.) can be used. As an apparatus for contact with a solid refrigerant, a contact refrigerator or the like can be mentioned, in which a metal plate is cooled from the inside or the outside with a cooling substance and frozen by being sandwiched between the metal plates. Examples of devices for blowing cold air include an air blast refrigerator that freezes with cooled air and a liquefied gas refrigerator that freezes by spraying liquefied gas boiled at a very low temperature.

The crushing section is configured to apply impact to the absorbent article 1 and crush the absorbent article 1 . Specifically, it is preferable that the crushing unit includes a crushing device capable of performing the above-described crushing process. As a crushing device, for example, a so-called crusher or crusher can be used. Examples of crushers and crushers include compression crushers, impact crushers, grinding crushers, shear crushers, and devices combining these. A compression crusher is a device that crushes an object by compressing it, and includes, for example, a jaw crusher, a gyratory crusher, a cone crusher, a roll crusher, and the like. The impact crusher is a device that crushes an object by impacting it with a hammer, impact plate, or the like. etc. A grinding-type crusher is a device that crushes an object by grinding it. , a bead mill, and the like. A shear-type crusher is a device that crushes an object by shearing it, and examples thereof include a cutter mill, a single-screw crusher, and a twin-screw crusher.

The separation section is configured to be able to separate the sheet piece 8 originating from the top sheet 2 or the back sheet 3 and the absorbent material. Specifically, the separation unit preferably includes a separation device capable of performing the separation process described above. Examples of separation devices include devices using screens and filters, devices using airflow, devices using gravity, devices using vibration, devices using rollers, and devices combining these. . A device using a screen or a filter is a device for separating according to the mesh size of the screen or filter, and examples thereof include a sieve, a filter, and a screen. Devices that use airflow are devices that separate fluids such as air and liquids by specific gravity and shape. A jet separator etc. are mentioned. Devices that use gravity are devices that separate by using the falling speed and sedimentation depending on the specific gravity and shape. is mentioned. A device using vibration is a device that promotes separation by vibration, and examples thereof include a vibrating sieve, a gyro-sifter, a circular vibrating sieve, a Urus screen, and a ballistic separator. A device using rollers is a device that separates by the difference in the gap due to the difference in the size of the rollers. Examples of combined separation devices include a vario separator that combines filter separation, airflow separation, and vibration separation.

Either or both of the crushing section and the separating section preferably have cooling means. As the cooling means, one capable of maintaining the temperature of the crushing section or the separating section at a temperature at which the water content in the absorbent article 1 can be maintained in a frozen state can be used. Examples of such cooling means include a method of crushing or separating while immersed in liquid refrigerant, a method of crushing or separating while being in contact with solid refrigerant, a method of crushing or separating while blowing cold air, and Apparatuses capable of performing a method combining these methods and the like are exemplified. The method of separating or crushing while immersed in liquid refrigerant is to maintain the frozen state by immersing in liquid refrigerant such as brine (salt solution, alcohol, etc.), liquefied gas (liquid nitrogen, liquid carbon dioxide, etc.). Alternatively, a method of separating may be used. A method of contacting with a solid refrigerant includes a method of cooling a metal plate of a crusher or a separator from the inside or outside with a cooling substance, and maintaining a frozen state by crushing or separating with the metal plate. The method of blowing cold air is to blow cooled air to the crusher or separator, supply cooled air to the crusher or separator to maintain a frozen state, or blow liquefied gas boiled at ultra-low temperature to the crusher. Alternatively, a method of spraying on a separator, or supplying a liquefied gas boiled at an ultra-low temperature to a crusher or a separator to maintain a frozen state, or the like can be used.

It is preferable that the manufacturing apparatus of the present embodiment include a water content reducing section that reduces the water content of the collected sheet pieces 8 . It is preferable that the water content reduction unit includes a water content reduction device capable of performing the above-described water content reduction step. The water content reducing section may be arranged between the separation section and the forming section, or may be included in the forming section. Examples of the moisture reduction device include a drying device, a dehydrating device, and a device combining these devices. The drying device is a device capable of performing the drying process described above, and the dehydration device is a device capable of performing the dehydration process described above. The water content reduction unit may include either one or both of a drying device and a dehydration device as the water content reducing device.

The molding unit is configured to mold the collected sheet pieces 8 into the recycled molding 10 . Specifically, the molding section preferably includes a molding device capable of performing the molding process described above. Also, the molding section may be provided with either one or both of the heating device and the compression device. Examples of molding equipment include fluff fuel manufacturing equipment, bale molded product manufacturing equipment, pellet manufacturing equipment, and the like. As the fluff fuel production apparatus, for example, an apparatus capable of performing the above-described method of forming the sheet piece 8 into the fluff fuel can be used. As the veil molded article manufacturing apparatus, for example, an apparatus capable of performing the above-described method of forming the sheet piece 8 into a veil molded article can be used. As the pellet manufacturing device, for example, a device capable of performing the above-described method of forming the sheet piece 8 into a pellet can be used. method, ring die method, hot cut method, screw method and the like. Moreover, it is preferable that the pellet manufacturing apparatus be capable of manufacturing the porous pellets described above. The pellet manufacturing apparatus is preferably a flat die type, ring die type, screw type, or the like, from the viewpoint of easy production of porous pellets.

Although the present invention has been described above based on its preferred embodiments, the present invention is not limited to the above embodiments.
For example, in the manufacturing method of the first embodiment, a sieve was used in the separation step, but instead of this, an air stream is applied to the crushed mixture of the absorbent article 1 to separate lumps of absorbent material having a small size. The sheet piece originating from the top sheet 2 or the back sheet 3 and the absorbent material may be separated by moving the sheet to the location of .

Further, when the absorbent article 1 contains excrement as in the manufacturing methods of the first and second embodiments, in the separation step, the sheet pieces derived from the top sheet 2 or the back sheet 3 and the absorbent It is preferred to separate material and waste. As a result, it is possible to separate and collect the sheet piece containing no excrement from the absorbent material and excrement. When separating the sheet pieces from the absorbent material and excrement, the sheet pieces may be separated into a mixture of the absorbent material and the excrement, or the sheet pieces, the absorbent material and the excrement may be separated. can be separated into Since excrement contains moisture, inorganic substances, and chlorides, the separated sheet pieces contain less moisture, ash, and chlorine, and are suitable for recycling.

The present invention further discloses the following remarks.
<1>
A recycled molded article obtained from sheet pieces collected from used absorbent articles,
A moisture content of 5% by mass or less, an ash content of 10% by mass or less, a total chlorine content of 0.3% by mass or less, and a total calorific value measured according to JIS Z 7302-2 A recycled molded article, which is 25 MJ/kg or more.
<2>
A recycled molded article obtained from sheet pieces collected from used absorbent articles,
A moisture content of 3% by mass or less, an ash content of 5% by mass or less, a total chlorine content of 0.6% by mass or less, and a total calorific value measured according to JIS Z 7302-2 A recycled molded article, which is 33 MJ/kg or more.

<3>
The recycled molded article according to <1> or <2>, wherein the recycled molded article is a pellet.
<4>
The recycled molded article according to <3>, wherein the recycled molded article is porous.
<5>
A method for producing a recycled molded article according to any one of <1> to <4> above, comprising:
recovering the sheet pieces from the used absorbent article;
A method for producing a recycled molded article, comprising a step of molding the collected sheet pieces into a recycled molded article.
<6>
The absorbent article includes an absorbent body having an absorbent material, a topsheet and a backsheet,
The step of recovering the sheet pieces from the used absorbent article,
a freezing step of freezing water in the absorbent article;
After the freezing step, a crushing step of applying an impact to the absorbent article to crush the absorbent article, and
The method for producing a recycled molded article according to <5>, further comprising a separation step of separating sheet pieces derived from the topsheet or the backsheet from the absorbent material after the crushing step.

<7>
The method for producing a recycled molded article according to <6>, further comprising a rough crushing step of roughly crushing the absorbent article prior to the freezing step.
<8>
The method for producing a recycled molded article according to <6> or <7>, wherein the crushing step is performed at a temperature at which water in the absorbent article can be maintained in a frozen state.
<9>
The method for producing a recycled molded article according to any one of <6> to <8>, wherein the separation step is performed at a temperature at which water in the absorbent article can be maintained in a frozen state.
<10>
The temperature at which the moisture in the absorbent article can be kept frozen is preferably 0° C. or lower, more preferably −5° C. or lower, and still more preferably −10° C. or lower at 1 atm, The method for producing a recycled molded article according to <8> or <9>, wherein the temperature is even more preferably −20° C. or lower.
<11>
The recycling according to any one of <6> to <10>, wherein in the separation step, the sheet pieces derived from the top sheet or the back sheet and the absorbent material are separated while vibrating. A method for producing a molded article.

<12>
The absorbent article includes an absorbent body having an absorbent material, a topsheet and a backsheet,
The step of recovering the sheet pieces from the used absorbent article,
a coarse crushing step of roughly crushing the absorbent article;
a freezing step of freezing moisture in the absorbent article after the rough crushing step; and
The method for producing a recycled molded article according to <5>, further comprising a separation step of separating sheet pieces derived from the top sheet or the back sheet from the absorbent material after the freezing step.
<13>
The absorbent article includes a used absorbent article containing excrement,
The method for producing a recycled molded article according to any one of <6> to <12>, wherein in the separating step, the sheet pieces are separated from the absorbent material and the excrement.
<14>
The method for producing a recycled molded article according to any one of <6> to <13>, wherein the freezing step is performed by placing the absorbent article under low temperature conditions.
<15>
The recycled molded article according to any one of <6> to <14>, wherein the freezing step is preferably carried out at -5°C or lower, more preferably -10°C or lower, and even more preferably -20°C or lower. Production method.

<16>
The method for producing a recycled compact according to any one of <6> to <15>, wherein the crushing step is performed using a crusher or a crusher.
<17>
Any of <6> to <15> above, wherein the crushing step is performed using a compression crusher, impact crusher, grinding crusher, shear crusher, or a device in which these are combined. 2. A method for producing a recycled molded article according to 1 above.
<18>
The sheet pieces obtained after the crushing step preferably have a size that cannot pass through a 2 mm sieve, preferably a size that cannot pass through a sieve with an opening of 5 mm, and a size that cannot pass through a 10 mm sieve. The method for producing a recycled molded article according to any one of <6> to <17>, wherein the size is preferably small, and more preferably the size is such that it cannot pass through a 20 mm sieve.
<19>
The mass of the absorbent material obtained after the crushing step preferably has a size that allows it to pass through a sieve with an opening of 2 mm, preferably a size that allows it to pass through a sieve with an opening of 5 mm, and preferably 10 mm. The method for producing a recycled molded article according to any one of <6> to <18> above, preferably having a size that can pass through a sieve of 20 mm, more preferably a size that can pass through a sieve of 20 mm. .

<20>
If the moisture content of the collected sheet pieces exceeds 5% by mass, the moisture content is reduced until the moisture content of the sheet pieces 8 is 5% by mass or less in the moisture content reduction step. , the method for producing a recycled molded article according to any one of <5> to <19>.
<21>
The method for producing a recycled molded article according to <20> above, wherein the water content reduction step includes either one or both of a drying step and a dehydrating step.
<22>
The method for producing a recycled molded article according to any one of <5> to <21>, wherein in the step of molding the collected sheet pieces into a recycled molded article, the sheet pieces are molded into pellets.
<23>
The method for producing a recycled molded body according to any one of <5> to <22>, wherein in the step of molding the collected sheet pieces into a recycled molded body, the sheet pieces are molded into porous pellets. .
<24>
Any one of <5> to <23>, wherein in the step of molding the collected sheet pieces into a recycled molded body, the recycled molded body is molded by a flat die method, a ring die method, or a screw method. A method for producing the described recycled molded article.

<25>
An apparatus for manufacturing a recycled molded body according to any one of <1> to <4>,
a sheet piece collecting unit for collecting sheet pieces from used absorbent articles;
An apparatus for manufacturing a recycled molded body, comprising: a molding section for molding the collected sheet pieces into a recycled molded body.
<26>
The absorbent article includes an absorbent body having an absorbent material, a topsheet and a backsheet,
The sheet piece recovery unit
a freezing unit that freezes moisture in the absorbent article;
a crushing unit that applies an impact to the absorbent article to crush the absorbent article; and
The apparatus for producing a recycled molded article according to <25>, further comprising a separation section for separating sheet pieces derived from the top sheet or the back sheet and the absorbent material.

<27>
The apparatus for producing recycled compacts according to <26>, wherein the freezing unit includes a device for immersing in a liquid refrigerant, a device for contacting with a solid refrigerant, a device for blowing cold air, or a device combining these.
<28>
The apparatus for manufacturing a recycled compact according to <26> or <27>, wherein the crushing unit includes a crusher or a crusher.
<29>
Any one of <26> to <28> above, wherein the crushing unit comprises a compression crusher, an impact crusher, a grinding crusher, a shear crusher, and a device combining these. 2. The apparatus for manufacturing the recycled molded article according to 1.
<30>
The apparatus for manufacturing recycled compacts according to any one of <26> to <29>, wherein one or both of the crushing section and the separating section have cooling means.
<31>
<26> to <30>.
<32>
The temperature at which the moisture in the absorbent article can be kept frozen is preferably 0° C. or lower, more preferably −5° C. or lower, and still more preferably −10° C. or lower at 1 atm, The apparatus for producing a recycled molded article according to <31>, wherein the temperature is even more preferably -20°C or lower.

<33>
If the water content of the collected sheet pieces exceeds 5% by mass, the water content reducing unit reduces the water content of the sheet pieces 8 to 5% by mass or less. , the apparatus for manufacturing a recycled compact according to any one of <26> to <32>.
<34>
The apparatus for manufacturing a recycled molded article according to <33>, wherein the moisture reduction unit includes either one or both of a drying device and a dehydrating device.
<35>
The apparatus for manufacturing recycled molded articles according to any one of <26> to <34>, wherein the molding unit includes a pellet manufacturing apparatus.
<36>
The apparatus for manufacturing recycled molded articles according to any one of <26> to <35>, wherein the molding unit includes a pellet manufacturing apparatus capable of manufacturing porous pellets.
<37>
The apparatus for manufacturing recycled molded articles according to any one of <26> to <36>, wherein the molding unit includes a flat die type, ring die type, or screw type pellet manufacturing apparatus.

The present invention will be described in more detail below based on examples, but the present invention is not limited to the following examples.

(Example 1)
As an absorbent article, Mary's tape diaper M size (Kao Corporation) was used. After 160 g of artificial urine was absorbed on the side of the absorbent article facing the skin in the central part of the crotch (the side facing the wearer's skin when worn), the absorbent article was left at room temperature for 10 minutes. Artificial urine contains 1.940% by weight of urea, 0.795% by weight of sodium chloride, 0.110% by weight of magnesium sulfate, 0.062% by weight of calcium chloride, 0.197% by weight of potassium sulfate, Red No. 2 (dye) 0 010% by weight, water (about 96.88% by weight) and polyoxyethylene lauryl ether (about 0.07% by weight), and the surface tension was adjusted to 53±1 mN/m (23° C.). It is. After absorbing artificial urine and leaving it at room temperature for 10 minutes, the absorbent article was placed in a freezer (manufactured by AS ONE, portable low-temperature refrigerator, model number: SC-DF25, Navis product number: 1-8757- 01) and frozen for 3 hours. After that, the absorbent article was taken out from the freezer and cut into 5 cm square rectangular pieces to obtain sample pieces. The sample piece was put into a crusher (manufactured by Osaka Chemical Co., Ltd., Wonder Crusher, type: WC-3, Nabis product number: 1-3380-01) and crushed for 10 seconds at a rotational speed memory of 3. The crushed sample pieces are placed on a sieve with an opening of 22.8 mm (manufactured by AS ONE, ISO3301-1/JIS Z-8801 stainless steel sieve 200Φ×60) and shaken to remove the constituent material of the absorbent article. Those that could pass the sieve and those that could not were separated. Sheet pieces that could not pass through the sieve were collected and designated as Example 1.

Regarding Example 1, in each of the following cases (i) to (iv), the total calorific value, moisture content, ash content, and total chlorine content were measured according to JIS Z 7302-2, JIS It was measured according to Z 7302-3, JIS Z 7302-4 and JIS Z 7302-6. Table 2 shows the measurement results.
(i) Immediately after collection and before drying.
(ii) dried to a water content of 0% by mass;
(iii) Dry to a moisture content of 3% by mass.
(iv) Dry to a moisture content of 5% by mass.

(Comparative example 1)
Merries tape diaper M size (Kao Corporation) was cut into rectangular pieces of 5 cm square to obtain sample pieces. This sample piece was designated as Comparative Example 1. Regarding Comparative Example 1, in the same manner as in Example 1, the total calorific value, moisture content, ash content, and total chlorine content were measured. Table 2 shows the measurement results.

(Comparative example 2)
As in Example 1, the absorbent article was allowed to absorb artificial urine and left at room temperature for 10 minutes. The absorbent article left at room temperature for 10 minutes was cut into rectangular pieces of 5 cm square to obtain sample pieces. This sample piece was designated as Comparative Example 2. As for Comparative Example 2, the total calorific value, moisture content, ash content, and total chlorine content were measured in the same manner as in Example 1. Table 2 shows the measurement results.

(Comparative Example 3)
As in Example 1, the absorbent article was allowed to absorb artificial urine and left at room temperature for 10 minutes. After being left at room temperature for 10 minutes, the absorbent article was further left at room temperature for 4 hours. Thereafter, the absorbent article was cut into 5 cm square rectangular pieces to obtain sample pieces. The sample pieces were put into a crusher in the same manner as in Example 1, and crushed for 10 seconds at a rotational speed memory of 3. The crushed sample pieces were placed in a CaCl aqueous solution with a concentration of 5%, and the small pieces that floated were collected. The small piece was placed in a nylon mesh bag of 250 mesh and dehydrated with a stretching dehydrator to obtain a sheet piece. This sheet piece was designated as Comparative Example 3. As for Comparative Example 3, the total calorific value, moisture content, ash content, and total chlorine content were measured in the same manner as in Example 1. Table 2 shows the measurement results.

(Comparative Example 4)
Comparative Example 4 was obtained in the same manner as in Example 1 except for the following points.
- After absorbing the artificial urine and leaving it at room temperature for 10 minutes, the absorbent article was left at room temperature for 4 hours without being placed in a freezer.
Regarding Comparative Example 4, the total calorific value, moisture content, ash content, and total chlorine content were measured in the same manner as in Example 1. Table 2 shows the measurement results.

As shown in Table 2, Example 1 has a total calorific value of 27 MJ/kg in case (i), which is higher than Comparative Examples 1-4. In the case of (i), Example 1 has an ash content of 4% by mass, a water content of 25% by mass, and a total chlorine content of 0.1% by mass. Except for the content, it meets the grade A RPF quality (see Table 1). As Example 1 is dried and the moisture content is reduced, the total calorific value increases accordingly. More specifically, when the water content is 5% by mass, 3% by mass, and 0% by mass, the total calorific value is 34 MJ/kg, 35 MJ/kg, and 36 MJ/kg, respectively (Table 2 , see (ii) to (iv) of Example 1). In addition, in cases (ii) to (iv), Example 1 satisfies not only the RPF quality of grade A but also the RPF-coke quality (see Table 1).

On the other hand, in Comparative Examples 1 to 4, in any of the cases (i) to (iv), the total calorific value, ash content, moisture content, and total chlorine content are grade A RPFs. does not meet the quality of
From the results of Example 1 and Comparative Examples 1 to 4, it can be seen that the manufacturing method of the present embodiment is a simple method and yet capable of manufacturing a recycled molding suitable for thermal recycling and chemical recycling.

Further, when comparing Example 1 and Comparative Example 3, in any of the cases (i) to (iv), the total calorific value is higher in Example 1, and the total chlorine content is lower in Example 1. In the cases (ii) to (iv), the ash content of Example 1 is less than or equal to that of Comparative Example 1. For this reason, unlike the manufacturing method of the present embodiment, it does not include the step of wetting the absorbent article or its crushed material with an aqueous solution of an inactivating agent containing a large amount of inorganic substances and chlorides, but includes the step of freezing the absorbent article. It can be seen that a high-quality recycled compact having a high total calorific value, a low ash content and a low total chlorine content can be obtained.

Further, when comparing Example 1 and Comparative Example 4, in any of the cases (i) to (iv), the total calorific value is higher in Example 1, and the total chlorine content is lower in Example 1. In the cases (ii) to (iv), the ash content of Example 1 is lower than that of Comparative Example 1. From this, it can be concluded that by including the step of freezing the absorbent article like the manufacturing method of the present embodiment, the total calorific value can be reduced because excrement including urine containing water, inorganic substances and chlorides can be removed. It can be seen that it is possible to obtain a high-quality recycled molded product with a high ash content and a low total chlorine content.

REFERENCE SIGNS LIST 1 absorbent article 2 topsheet 3 backsheet 4 absorbent body 8 piece of sheet derived from topsheet or backsheet 9 mass of absorbent material

Claims (4)

A method for producing a recycled molded article by collecting sheet pieces from used absorbent articles and producing a recycled molded article from the sheet pieces,
recovering the sheet pieces from the used absorbent article;
forming the collected sheet pieces into a recycled formed body,
The absorbent article includes an absorbent body having an absorbent material, a topsheet and a backsheet,
The step of recovering sheet pieces from the absorbent article comprises:
a freezing step of freezing water in the absorbent article;
After the freezing step, a crushing step of applying an impact to the absorbent article to crush the absorbent article, and
After the crushing step, a separating step of separating sheet pieces derived from the top sheet or the back sheet and the absorbent material ,
The recycled compact has a moisture content of 5% by mass or less, an ash content of 10% by mass or less, and a total chlorine content of 0.3% by mass or less, and
A method for producing a recycled molded article having a total calorific value of 25 MJ/kg or more as measured according to JIS Z 7302-2 . A method for producing a recycled molded article by collecting sheet pieces from used absorbent articles and producing a recycled molded article from the sheet pieces,
recovering the sheet pieces from the used absorbent article;
forming the collected sheet pieces into a recycled formed body,
The absorbent article includes an absorbent body having an absorbent material, a topsheet and a backsheet,
The step of recovering sheet pieces from the absorbent article comprises:
a freezing step of freezing water in the absorbent article;
After the freezing step, a crushing step of applying an impact to the absorbent article to crush the absorbent article, and
After the crushing step, a separating step of separating sheet pieces derived from the top sheet or the back sheet and the absorbent material ,
The recycled compact has a moisture content of 3% by mass or less, an ash content of 5% by mass or less, and a total chlorine content of 0.6% by mass or less, and
A method for producing a recycled molded product , wherein the total calorific value measured according to JIS Z 7302-2 is 33 MJ/kg or more . 3. The method for producing a recycled molded article according to claim 1, wherein said recycled molded article is a pellet. 4. The method for producing a recycled molded article according to claim 3, wherein said recycled molded article is porous.

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