JP2004091977A - Impurity-removing method in production of waste paper pulp, method for producing waste paper pulp and printing paper - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve the efficiency for removing impurities in no sorting treatment of a waste paper. <P>SOLUTION: The impurities are removed by inserting not only newspaper and leaflets but also a waste paper of a magazine, a book or the like having subsidiaries made of resin sheets such as filed bag for a CD mixed therewith without sorting them to a main breaker 1 to form a fiber suspension, subjecting the fiber suspension to auxiliary disintegration by an assistant breaker 2 to disintegrate unbroken components, discharging the broken product through a discharging screen comprising a hole screen having ≥2.2mm eyelets, and passing the screened product through a hole screen having ≥1.4mm eyelets and a slit screen having ≤0.15mm slit width. The resin impurities having various sizes can be efficiently removed by combining the sizes and kinds of the screens. <P>COPYRIGHT: (C)2004,JPO

Description

【００２０】
【発明の効果】
以上のように、本発明によれば、古紙の無選別処理における夾雑物、特に樹脂シート製付属物由来の夾雑物の除去効率が向上する。また、古紙パルプおよび再生紙の高品質化を図ることができる。
【図面の簡単な説明】
【図１】実施形態のフロー図である。
【符号の説明】
１…主離解装置、２…補助離解装置、２Ｓ…排出スクリーン、４Ｈ…ホールスクリーン、４Ｓ…スリットスクリーン。[0001]
TECHNICAL FIELD OF THE INVENTION
TECHNICAL FIELD The present invention relates to a technique for processing waste paper, including one with an accessory made of a resin sheet, without sorting.
[0002]
[Prior art]
Waste paper pulp, which is a raw material for recycled paper, is made by dissolving waste paper, such as newsprints and flyers, from which various types of impurities are unlikely to appear, forming a suspension, and then removing the impurities, deinking, and bleaching. Are generally manufactured in order, and used paper such as magazines and books is hardly used. This is because the waste paper such as magazines and books has hot glue or other back glue remaining, and a compact disc (hereinafter simply referred to as a CD) as an appendix is sandwiched between pages. This is because there is a risk that the image quality may decrease, quality of recycled paper may be degraded, and printing failure may be caused.
[0003]
However, from the viewpoint of effective use of resources, it is desirable to use waste paper such as magazines and books. In particular, if used paper such as magazines and books can be used without being separated from used paper such as newspapers and flyers, it is also desirable in that the labor for sorting used paper can be saved.
[0004]
Therefore, as shown in the above-mentioned Japanese Patent Application Laid-Open No. 2002-155482, the present applicant can use recycled paper containing hot-melt or CD-containing hot-melt and alkali-meltable materials without sorting. A possible and economical waste paper pulp manufacturing method was proposed.
[0005]
[Problems to be solved by the invention]
However, although a certain weight such as a CD can be easily removed, accessories such as a vinyl bag or film for binding the CD and a vinyl document request envelope are lightweight, and may be heat or alkaline. Therefore, it is difficult to efficiently remove the contaminants by the conventional method. For this reason, it has been still difficult to produce high-quality waste paper pulp by unsorted waste paper and to manufacture recycled paper that can be used for printing from waste pulp made from unsorted waste paper.
[0006]
Therefore, a main object of the present invention is to improve the efficiency of removing foreign substances in the non-sorting of waste paper. Another problem is to improve the quality of waste paper pulp and recycled paper.
[0007]
[Means for Solving the Problems]
The present invention that has solved the above problems is as described below.
<Invention according to claim 1>
A method of processing unsorted waste paper,
A main defibration step of dissolving the waste paper to form a fiber suspension,
An auxiliary disintegration step of disintegrating the undisintegrated fraction in the fiber suspension obtained in this main disintegration hand step and discharging the same through a hole screen having a hole size of 2.2 mm or more;
And a contaminant removing step of separating and removing contaminants by passing the fiber suspension having passed through the auxiliary disaggregation step through a hole screen having a hole size of 1.4 mm or more and a slit screen having a slit width of 0.15 mm or less in this order. ,
A method for removing contaminants in the production of waste paper pulp, characterized in that:
[0008]
<Invention according to claim 2>
A method for producing waste paper pulp, comprising subjecting the fiber suspension from which impurities have been removed by the method according to claim 1 to deinking treatment and bleaching treatment to obtain waste paper pulp.
[0009]
<Invention of Claim 3>
Printing paper produced by using pulp produced by the method according to claim 2.
[0010]
(Effect)
When the used paper with the attachment made of the resin sheet (including the resin film) is defibrated by the pulper, the attachment made of the resin sheet is crushed together with the pulp fibers. The problem here is that the shape and size of the contaminants derived from the resin sheet (hereinafter referred to as resin sheet contaminants) are not uniform. Moreover, as described above, these impurities are suspended in the suspension together with the pulp fibers, so that it is difficult to separate them using the specific gravity difference. Therefore, it is difficult to remove the resin sheet contaminants efficiently by the conventional method that does not assume these matters.
[0011]
However, according to the present invention, the suspension which has been subjected to assisted disintegration is discharged through a hole screen having a hole size of 2.2 mm or more, and is discharged in a later step into a hole screen having a hole size of 1.4 mm or more and a slit screen having a slit width of 0.15 mm or less. Are passed in this order, it is possible to efficiently separate and remove the resin sheet contaminants. This is because the efficiency is good if the screen size is reduced in order and the large impurities are separated and removed in a stepwise manner.The front hole screen is suitable for separating and removing the large impurities, and the rear slit screen is small. This is because it is suitable for separating and removing contaminants.
[0012]
By using such a foreign matter removal method, waste paper pulp containing less foreign matter can be manufactured, and if this method is used, high-quality recycled paper that can be used as printing paper can be manufactured.
[0013]
In the present specification, the term “unsorted waste paper” includes not only waste magazines consisting only of so-called magazines, but also newspapers, flyers, magazines with pins, magazines with back glue, magazines with vinyl, and magazines with CDs. Shall be considered.
[0014]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.
FIG. 1 shows a flow chart for producing recycled paper according to the present invention. In the present invention, as the raw material waste paper, in addition to newspapers and flyers, non-sorted waste paper in which a magazine waste paper with an accessory made of a resin sheet such as a CD binding bag or a book is mixed is used. The raw material waste paper is first introduced into the main defibrating device 1 that performs defibration (fibrillation) by a mechanical stirring force of a pulper or the like, and is defibrated in a dissolving solution such as water to form a fiber suspension (main defibration).
[0015]
The fiber suspension subjected to the main defibration treatment is sent to the auxiliary defibration device 2 having a defibration function and a separating function, and the undisintegrated components in the fiber suspension are defibrated (auxiliary defibration). The auxiliary disintegration device 2 has a discharge screen 2H composed of a hole screen having a hole size of 2.2 mm or more, particularly 2.2 to 5.5 mm, and discharges the processing liquid via the discharge screen 2H.
[0016]
The fiber suspension thus subjected to the defibration treatment is used to remove CD fragments, staples, and the like by a specific gravity difference separator (not shown) as necessary, and then to have a hole of 1.4 mm or more, particularly 1.4 to 2.0 mm. Through a hole screen 4H and a slit screen 4S having a slit width of 0.15 mm or less, particularly 0.10 to 0.15 mm, to separate and remove impurities (coarse selection). With such a combination of screen size and type, even resin sheet contaminants whose sizes and shapes are not uniform can be efficiently removed. In addition, as long as this order is followed, for example, after performing separation using a hole screen having a hole diameter of 1.4 mm or more in a plurality of stages, separation using a slit screen having a slit width of 0.15 mm or less is performed in a plurality of stages, or a screen of another size is used. It is also included in the present invention to intervene before, after or between these screens.
[0017]
The fiber suspension from which impurities have been removed in this way is subjected to, for example, deinking treatment 5 by flotation, bleaching treatment 10 using hydrogen peroxide or the like, and dehydration treatment 13, and High quality waste paper pulp can be obtained by combining the separation and removal of contaminants at the stage and the dispersion treatment. Further, high-quality recycled paper that can be used as printing paper can be manufactured by using such waste paper pulp as part or all of the raw material.
[0018]
【Example】
Using unsorted waste paper including waste paper with resin sheets, such as CD binding bags and envelopes for requesting materials, we manufacture waste paper pulp and conduct a production test of recycled paper using the waste paper pulp to remove resin sheet contaminants. And the suitability of the recycled paper for printing paper was evaluated on a three-point scale. In this test, the conditions other than the screen were common. Table 1 shows the conditions and results. The efficiency of removing contaminants in the resin sheet according to the present invention is significantly improved as compared with the conventional case.
[0019]
[Table 1]

[0020]
【The invention's effect】
INDUSTRIAL APPLICABILITY As described above, according to the present invention, the removal efficiency of impurities in the non-sorting of waste paper, particularly the impurities derived from resin sheet accessories, is improved. Further, the quality of the used pulp and the recycled paper can be improved.
[Brief description of the drawings]
FIG. 1 is a flowchart of an embodiment.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Main disintegration apparatus, 2 ... Auxiliary disintegration apparatus, 2S ... Discharge screen, 4H ... Hole screen, 4S ... Slit screen.

Claims (3)

A method of processing unsorted waste paper,
A main defibration step of dissolving the waste paper to form a fiber suspension,
An auxiliary disintegration step of disintegrating the undisintegrated fraction in the fiber suspension obtained in this main disintegration hand step and discharging the same through a hole screen having a hole size of 2.2 mm or more;
And a contaminant removing step of separating and removing contaminants by passing the fiber suspension having passed through the auxiliary disaggregation step through a hole screen having a hole size of 1.4 mm or more and a slit screen having a slit width of 0.15 mm or less in this order. ,
A method for removing contaminants in the production of waste paper pulp, characterized in that: A method for producing waste paper pulp, comprising subjecting a fiber suspension from which impurities have been removed by the method according to claim 1 to deinking and bleaching to obtain waste paper pulp. A printing paper manufactured by using pulp manufactured by the method according to claim 2.

Images