Unicharm Corporation

Hiroshima University

Toshio Hiraoka

Takayoshi Konishi

Noritomo Kameda

Noritomo Kurita

Koichi Yamaki

Hideaki Ichiura

Takashi Kato

Hiroko Nakaoka

Ayami Suga

Naoto Ohashi

Masaki Yoshida

Kouichi Yamaki

Yoshihide Ishikawa

Takahiro Ueda

Hiromi Yamada

Toshihide Kakizono

Toshifumi Hikosaka

The purpose of the present invention is to provide a method for producing recycled pulp fibers such that articles using the recycled pulp fibers can easily achieve a uniform whiteness and users are not prone to feel psychological resistance to articles using the recycled pulp fibers. This method is described below. The method is characterized by involving: a step for supplying, from a mixed solution supply port () to a treatment tank (), a mixed solution () which contains superabsorbent polymers and pulp fibers derived from multiple types of used sanitary products; a step for supplying an ozone-containing gas () from an ozone-containing gas supply port () to a treatment solution () inside of the treatment tank (); a step in which, by raising the ozone-containing gas () while lowering the superabsorbent polymers and pulp fibers in the treatment tank (), the ozone-containing gas () is brought into contact with the superabsorbent polymers and the pulp fibers, and the pulp fibers are bleached to form recycled pulp fibers; and a step for discharging the treatment solution () from a treatment solution discharge port (), wherein the recycled pulp fibers have a-ΔYI with respect to a standard white plate.

Method for producing recycled pulp fibers, and recycled pulp fibers

The purpose of the present invention is to provide a method which is for producing pulp fibers for cellulose nanofiberization from pulp fibers of used sanitary products, and which can produce pulp fibers for cellulose nanofiberization that have low lignin content and a low distribution thereof and that have excellent cellulose nanofiberization properties. This method is described below. The method is characterized by involving: a step for supplying, from a mixed solution supply port () to a treatment tank (), a mixed solution () which contains superabsorbent polymers and pulp fibers derived from used sanitary products; a step for supplying an ozone-containing gas () from an ozone-containing gas supply port () to a treatment solution () inside of the treatment tank (); a step in which, by raising the ozone-containing gas () while lowering the superabsorbent polymers and pulp fibers in the treatment tank (), the ozone-containing gas () is brought into contact with the superabsorbent polymers and the pulp fibers, and pulp fibers for cellulose nanofiberization are formed from the pulp fibers; and a step for discharging the treatment solution () from a treatment solution discharge port (), wherein the pulp fibers for cellulose nanofiberization have a lignin content of less than or equal to 0.1 mass %.

Method for producing pulp fibers for cellulose nanofiberization, and pulp fibers for cellulose nanofiberization

The purpose of the present disclosure is to provide a method for producing pulp fibres for saccharification from the pulp fibres of used sanitary items, said pulp fibres for saccharification having low lignin contents distributed within a narrow range, and enabling the production of pulp fibres for saccharification having superior saccharification properties. The production method according to the present disclosure is characterised by comprising the following: a step for supplying a mixed solution () containing pulp fibres and highly-absorbent polymers sourced from used sanitary items to a treatment tank () via a mixed-solution supply port (); a step for supplying an ozone-containing gas () to a treatment solution () within the treatment tank () via an ozone-containing-gas supply port (); a step for lifting the ozone-containing gas () whilst lowering the pulp fibres and highly-absorbent polymers within the treatment tank (), thereby bringing the ozone-containing gas () into contact with the pulp fibres and highly-absorbent polymers, and forming pulp fibres for saccharification from the pulp fibres; and a step for discharging the treatment solution () via a treatment-solution discharge port (). The method is further characterised in that the pulp fibres for saccharification have lignin contents of 0.1% or less.

Method for producing pulp fibres for saccharification, and aqueous solution of pulp fibres for saccharification

The purpose of the present invention is to provide a method for producing recycled pulp fibers such that articles using the recycled pulp fibers can easily achieve a uniform whiteness and users are not prone to feel psychological resistance to articles using the recycled pulp fibers. This method is described below. The method is characterized by involving: a step for supplying, from a mixed solution supply port () to a treatment tank (), a mixed solution () which contains superabsorbent polymers and pulp fibers derived from multiple types of used sanitary products; a step for supplying an ozone-containing gas () from an ozone-containing gas supply port () to a treatment solution () inside of the treatment tank (); a step in which, by raising the ozone-containing gas () while lowering the superabsorbent polymers and pulp fibers in the treatment tank (), the ozone-containing gas () is brought into contact with the superabsorbent polymers and the pulp fibers, and the pulp fibers are bleached to form recycled pulp fibers; and a step for discharging the treatment solution () from a treatment solution discharge port (), wherein the recycled pulp fibers have a-&#x394;YI with respect to a standard white plate.

Method for producing recycled pulp fibers by decomposing super absorbant polymers with ozone

A method includes producing recycled products from a plurality of used absorbent articles, each including a top sheet, a back sheet and an absorbent body including absorbent body materials, by recovering a plurality of structural members from the plurality of used absorbent articles. At least one of the top sheet and the back sheet includes a film. The method includes: separating the plurality of used absorbent articles into a plurality of the films and the absorbent body materials; sorting the plurality of films into a plurality of types of recyclable films according to the filler contents of the plurality of films; and forming a plurality of types of recycled resin pellets from the plurality of types of recyclable films.

Method for producing recycled product, recycled resin pellet, and recycled film

Provided is a method that, when pulp fibers are recovered from used absorbent articles that have been put into collection bags, makes it possible to safely and sanitarily crush the used absorbent articles while suppressing costs. A method for recovering pulp fibers from used absorbent articles, the method comprising: a crushing step (S) in which collection bags (A) in which used absorbent articles have been sealed are put into a container (), the collection bags in the container are transferred to a crushing device () that communicates with the container, and, bag by bag, the crushing device crushes the used absorbent articles in the collections bags in a deactivating aqueous solution; and a separation step (S) in which the pulp fibers, a highly water-absorbent polymer, and the deactivating aqueous solution are separated from the crushed product and deactivating aqueous solution obtained in the crushing step.

Method and system for recovering pulp fibers from used absorbent articles

Recycled pulp that derives from a used sanitary article includes an antibacterial activity value of 2.0 or more and an acid. Recycled pulp that derives from a used sanitary article includes an antibacterial activity value of 2.0 or more and an ash content of 0.65% by weight or less, and further includes an acid. The acid is a citric acid. The recycled pulp further includes a cationic antibacterial agent. The cationic antibacterial agent is a quaternary ammonium salt. The cationic antibacterial agent is a benzalkonium chloride or a cetylpyridinium chloride. At least a portion of the cationic antibacterial agent is adsorbed on the recycled pulp.

Recycled pulp, absorbent, non-woven fabric, and sanitary article

A recycled pulp that is reusable sanitary products is efficiently manufactured by recovering pulp fiber from used sanitary products containing the pulp fiber and a polymer absorbent. The method of the present invention comprises: a step applying a mechanical force to the used sanitary products in an aqueous solution containing a polyvalent metal ion or an acidic aqueous solution with a pH of 2.5 or lower and thus degrading the used sanitary products into the pulp fiber and other materials; a step separating the pulp fiber from the mixture of the pulp fiber and other materials that has been formed in the degradation step; and a step treating the pulp fiber thus separated with an ozone-containing aqueous solution with a pH of 2.5 or lower.

Method for manufacturing recycled pulp from used sanitary products

A method of recovering structural members from a used absorbent article comprising a front sheet, a back sheet and an absorbent body between the front sheet and the back sheet, wherein at least one of the front sheet and the back sheet includes a film, and wherein the absorbent body includes an absorbent body material, may include swelling the used absorbent article with water, applying a physical shock to and disintegrating the swelled used absorbent article into at least the film and the absorbent body material, and separating the film and the absorbent body material.

Method for recovering constituent members from used absorbent article

A simple method is provided for producing a saccharified solution from a used absorbent article such as a used diaper. In order to produce a saccharified solution from a used absorbent article comprising a non-cellulosic liquid permeable surface material and an absorbent body that contains pulp fibers, the used absorbent article is immersed, without first being decomposed, in a saccharifying enzyme solution containing cellulase. The pulp fibers in the used absorbent article are saccharified by the cellulase, producing a saccharified solution. The produced saccharified solution is exuded out of the used absorbent article through the liquid permeable surface material, so it is possible to easily separate and recover the saccharified solution from the used absorbent article while maintaining the outer shape.

Method of producing saccharified solution from used absorbent article

The present invention provides a method which, in the process of manufacturing recycled pulp fibers from a mixture of pulp fibers and a high water-absorption polymer, enables efficient manufacturing of the recycled pulp fibers while properly removing the high water-absorption polymer from the pulp fibers. This method comprises: a supply step (S-) for supplying an aqueous solution containing a mixture () to a driving fluid supply port (DI) of an ejector () and simultaneously supplying, to a suction fluid supply port (AI) of the ejector, a gaseous substance (Z) which is capable of degrading a high water-absorption polymer so as to make the degraded polymer dissolvable; and a treatment step (S-) for discharging, from a mixed fluid discharge port (CO) of the ejector that is connected to a lower part of a treatment tank (), a mixed liquid, which is formed when the aqueous solution and the gaseous substance are mixed within the ejector, into a treatment liquid (P) within the treatment tank, so as to lessen the high water-absorption polymer in the mixture.

Method for manufacturing recycled pulp fibers

The purpose of the present disclosure is to provide a recovery method for an organic acid. The recovery method makes it possible to efficiently recover an organic acid that is included in a deactivating aqueous solution that includes excrement. This recovery method has the following features. A method for recovering an organic acid that deactivates a highly water-absorbent polymer that is included in used absorbent articles, the method being characterized by including: a deactivation step (S) in which the highly water-absorbent polymer is immersed in a deactivating aqueous solution that includes an organic acid and has a prescribed pH and the highly water-absorbent polymer is deactivated; a highly water-absorbent polymer removal step (S) in which the deactivated highly water-absorbent polymer is removed from the deactivating aqueous solution; a pH adjustment step (S) in which the deactivating aqueous solution is adjusted to a prescribed pH; a concentration step (S) in which the deactivation step (S), the highly water-absorbent polymer removal step (S), and the pH adjustment step (S) are repeated using deactivating aqueous solution that has gone through the pH adjustment step (S) and the organic acid in the deactivating aqueous solution is concentrated; and an organic acid recovery step (S) in which the organic acid is recovered from the deactivating aqueous solution.

Recovery method for organic acid, and production method for recycled pulp

Pulp fiber containing little ash is effectively recovered from a used sanitary product containing the pulp fiber and a polymer absorbent. The method according to the present invention comprises: a step for treating the used sanitary product with an ozone-containing gas and thus decomposing and removing at least a portion of the polymer absorbent in the used sanitary product; and a step for stirring the used sanitary product, that has been treated with the ozone-containing gas, in water or an aqueous solution containing an antiseptic and thus decomposing the used sanitary product into constituents. If required, the method may further comprise a step for separating the pulp fiber from the decomposition product obtained by the decomposition step.

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Kagawa, Japan

Toshio Hiraoka