Water absorbing material and manufacturing method thereof

Patent metadata

Field	Value
Publication number	US-9393546-B2
Application number	US-201514833697-A
Country	US
Kind code	B2
Filing date	Aug 24, 2015
Priority date	May 10, 2013
Publication date	Jul 19, 2016
Grant date	Jul 19, 2016

Abstract

A water absorbing material contains a water-absorbent material consisting of at least one of plastic and fluff pulp that are obtained by separating a water-absorbent polymer from a sanitary article containing the plastic, the fluff pulp and the water-absorbent polymer. The weight ratio of the water-absorbent polymer adhering to the water-absorbent material with respect to the water-absorbent material is 3% or less.

First claim

The invention claimed is:

1. A water absorbing material containing a water-absorbent material consisting of at least one of plastic and fluff pulp that are obtained by separating a water-absorbent polymer from a sanitary article containing the plastic, the fluff pulp and the water-absorbent polymer,
wherein a weight ratio of the water-absorbent polymer adhering to the water-absorbent material with respect to the water-absorbent material is 3% or less.

2. The water absorbing material according to claim 1 ,
wherein the water-absorbent polymer is separated from the sanitary article with a separation device, and
the separation device includes:
a first shredding unit that shreds the sanitary article; and
a first rough separation unit that has a first tubular portion in which a large number of first holes that allow the fluff pulp and the water-absorbent polymer to pass through without allowing the plastic contained in the sanitary article shredded by the first shredding unit to pass through are formed, and that separates the fluff pulp and the water-absorbent polymer passing through the first holes from the sanitary article by rotating the first tubular portion in a state in which the sanitary article shredded by the first shredding unit is accommodated in the first tubular portion.

3. The water absorbing material according to claim 2 ,
wherein the separation device includes a first fine separation unit that separates the fluff pulp and the water-absorbent polymer, which are separated from the sanitary article by the first rough separation unit, from each other.

4. The water absorbing material according to claim 2 ,
wherein the separation device includes a first ridge that is provided on an inner circumferential surface of the first tubular portion and that extends in a direction in which a central axis of the first tubular portion extends.

5. The water absorbing material according to claim 4 ,
wherein “p” of said first ridges are present, “p” being an integer between 3 and 5 inclusive, and the “p” first ridges are arranged on the inner circumferential surface of the first tubular portion at regular intervals.

6. The water absorbing material according to claim 2 ,
wherein the separation device includes a first air pipe for transferring the sanitary article shredded by the first shredding unit to the first rough separation unit with air pressure, and
the first air pipe has a first portion that extends in a first direction and a second portion that is connected to the first portion on a downstream side of the first portion and that extends in a second direction substantially orthogonal to the first direction.

7. The water absorbing material according to claim 6 ,
wherein the separation device includes a first uneven surface that is present in a connecting portion between the first portion and the second portion of the first air pipe and with which the sanitary article transferred through the first portion collides.

8. The water absorbing material according to claim 6 ,
wherein the first air pipe has a third portion that is connected to the second portion on a downstream side of the second portion and that extends in a third direction substantially orthogonal to the second direction.

9. The water absorbing material according to claim 8 ,
wherein the separation device includes a second uneven surface that is present in a connecting portion between the second portion and the third portion of the first air pipe and with which the sanitary article transferred through the second portion collides.

10. The water absorbing material according to claim 2 ,
wherein the separation device includes:
a second shredding unit that shreds the sanitary article from which the fluff pulp and the water-absorbent polymer passing through the first holes are separated by the first rough separation unit; and
a second rough separation unit that has a second tubular portion in which a large number of second holes that allow the fluff pulp and the water-absorbent polymer to pass through without allowing the plastic contained in the sanitary article shredded by the second shredding unit to pass through are formed, and that separates the fluff pulp and the water-absorbent polymer passing through the second holes from the sanitary article by rotating the second tubular portion in a state in which the sanitary article shredded by the second shredding unit is accommodated in the second tubular portion.

11. The water absorbing material according to claim 10 ,
wherein the separation device includes a second fine separation unit that separates the fluff pulp and the water-absorbent polymer, which are separated from the sanitary article by the second rough separation unit, from each other.

12. The water absorbing material according to claim 10 ,
wherein an area of each of the second holes in a plan view is smaller than an area of each of the first holes in a plan view.

13. The water absorbing material according to claim 1 , comprising:
a granular core portion containing the water-absorbent material; and
a coating layer portion that covers the granular core portion.

14. The water absorbing material according to claim 13 ,
wherein the coating layer portion contains the fluff pulp and the water-absorbent polymer.

15. The water absorbing material according to claim 1 ,
wherein the water-absorbent material is a main material of the water absorbing material.

16. A manufacturing method of a water absorbing material comprising:
an obtaining step of separating a water-absorbent polymer from a sanitary article containing plastic, fluff pulp and the water-absorbent polymer to obtain a water-absorbent material consisting of at least one of the plastic and the fluff pulp; and
a granulating step of granulating the water-absorbent material obtained in the obtaining step,
wherein in the obtaining step, the water-absorbent polymer is separated from the sanitary article so that a weight ratio of the water-absorbent polymer adhering to the water-absorbent material with respect to the water-absorbent material will be 3% or less.

17. The manufacturing method of the water absorbing material according to claim 16 ,
wherein the obtaining step includes:
a first shredding step of shredding the sanitary article; and
a first rough separating step of rotating a first tubular portion in which a large number of first holes that allow the fluff pulp and the water-absorbent polymer to pass through without allowing the plastic contained in the sanitary article shredded in the first shredding step to pass through are formed, the first tubular portion being rotated in a state in which the sanitary article shredded in the first shredding step is accommodated in the first tubular portion, thereby separating the fluff pulp and the water-absorbent polymer passing through the first holes from the sanitary article.

18. The manufacturing method of the water absorbing material according to claim 17 ,
wherein the obtaining step includes a first fine separating step of separating the fluff pulp and the water-absorbent polymer, which are separated from the sanitary article in the first rough separating step, from each other.

19. The manufacturing method of the water absorbing material according to claim 17 ,
wherein the obtaining step includes:
a second shredding step of shredding the sanitary article from which the fluff pulp and the water-absorbent polymer passing through the first holes are separated in the first rough separating step; and
a second rough separating step of

Assignees

• Daiki Kk

Inventors

• Ito Hiroshi
• Yoshinaga Junji

Classifications

• B29L2031/4878

  Diapers, napkins · CPC title

• B01J20/3293

  Coatings on a core, the core being particle or fiber shaped, e.g. encapsulated particles, coated fibers · CPC title

• B01J2220/4831

  having been subjected to further processing, e.g. paper, cellulose pulp · CPC title

• B07B1/24

  with fixed or moving interior agitators · CPC title

• Y02W30/523

  Cross-Sectional Technologies · mapped topic