JP2005240189A - Liner for corrugated board and method for producing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a liner for corrugated board saving global resources and suppressing environmental disruption by effectively utilizing a reject discharged from a production process of deinked pulp. <P>SOLUTION: The reject discharged from the production process 10 of the deinked pulp is added to a pulp raw material for a production process 11 of the liner for the corrugated board. Thereby, the reject in an amount within the range of 1-25 wt.% is contained in the middle and/or back surface layer of the liner for the corrugated board. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a liner for corrugated paper and a method for producing the same.

  Conventionally, rejects discharged from a deinked pulp manufacturing process are not reused due to a high content of ink, pigment or filler, and are incinerated with a boiler or the like.

  In order to further increase the yield in the method of disaggregating and dispersing used paper raw materials such as coated paper, removing large foreign substances with a screen, washing with a high-speed washing machine and recovering and reusing pulp fibers, a washing process In order to collect the fiber in the white water discharged from the white water, a method is known in which the white water is applied to a specific gravity separation device such as a hydrocyclone to collect the fine fibers in the white water using the specific gravity difference (see, for example, Patent Document 1). .)

Further, in the method for producing an outer liner for corrugated paper using used corrugated paper, the waste discharged from the process of coarsely selecting and carefully selecting the screen after separating the used corrugated paper is guided to a reject processing system for dehydration, disaggregation, It is also known that it is introduced into the blended chest as a part of the intermediate layer production raw material through a coarse selection, a fine selection, and a washing process, and then a dehydration process and a beating process (see, for example, Patent Document 2).
JP-A-6-173183 JP-A-11-107186

  However, in the past, rejects discharged from the deinked pulp manufacturing process have been incinerated without being reused, so there is a problem of wasting earth resources, and rejects have a large amount of ash, so a large amount of rejects are also generated after incineration. There is a problem that sludge ash is generated and needs to be disposed of, which causes an increase in environmental destruction.

  In addition, the technique described in Patent Document 1 is intended to collect not only long fibers but also fine fibers in the coated paper to increase the yield, but the reject including the ash is reused. It is not a thing.

  The technique described in Patent Document 2 also processes the reject discharged from the manufacturing process of the outer liner using the corrugated cardboard and makes it a part of the middle layer raw material slurry. It is not intended to be reused.

  In view of the above-described conventional problems, the present invention provides a liner for corrugated paper and a method for producing the same that can effectively use rejects discharged from the deinked pulp manufacturing process, save earth resources, and suppress environmental destruction. The issue is to provide.

  The liner for corrugated paper of the present invention is a liner for corrugated paper in which a surface layer, one or a plurality of intermediate layers, and a back surface layer are laminated, and the intermediate layer and / or the back layer has a deinked pulp manufacturing process. 1 to 25% by weight of rejects discharged from the container.

  According to this configuration, the reject discharged from the deinked pulp manufacturing process can be effectively used by including the reject in the intermediate layer or the back layer of the liner for the cardboard paper, and at least 1% by weight or more is included. In this way, it is possible to save earth resources and suppress environmental destruction. Also, even if rejects are contained in the intermediate layer or back layer of the corrugated paper liner in an amount of 25% by weight or less, the function as the corrugated paper liner is not hindered, and it is not exposed on the outer surface of the corrugated paper. But there is no problem. If it exceeds 25% by weight, the adjustment of the wet end of the paper machine becomes unstable, which adversely affects the operability and increases the amount of contaminants, thereby deteriorating the product quality.

  Also, if the reject ash content is 50% or less, the operability will not be adversely affected and the product quality will not be affected, but if it exceeds 50%, the adjustment of the wet end of the paper machine becomes unstable. As a result, the operability is adversely affected, and impurities increase and the product quality deteriorates.

  Moreover, the manufacturing method of the liner for corrugated paper of this invention is 1-25 weight% of the reject discharged | emitted from the deinking pulp manufacturing process with respect to the pulp raw material of the intermediate | middle layer and / or back layer of a corrugated paper liner. Is added to make a cardboard paper liner, and the above-mentioned cardboard paper liner can be obtained and exert its effects.

  Further, when adjusting the pH of the reject to 7.0 to 5.5 at the time of acidic papermaking, if the reject is added to the pulp raw material, operation stability can be ensured.

  In addition, when the reject discharged from the deinked pulp manufacturing process is processed with a slit screen of 0.25 mm or less and then the raw material slurry is blended, large contaminants are not mixed into the product liner, and the product quality is surely deteriorated. This is preferable because it can be prevented.

  According to the present invention, effective use of rejection is achieved by containing the reject discharged from the deinked pulp manufacturing process in the range of 1 to 25% by weight in the intermediate layer and / or the back layer of the liner for cardboard paper. It is possible to save earth resources and suppress environmental destruction.

  Hereinafter, an embodiment of a liner for corrugated paper and a method for producing the same of the present invention will be described in detail with reference to FIG.

  In the deinking pulp manufacturing process 10, a deinking agent and an alkaline chemical are added to the waste paper mainly composed of printing waste paper, disaggregated by the pulper 1, dust is removed by the screen 2, and then the flotation by the flow meter 3. The ink is floated and removed by the treatment, and then carefully selected by the cleaner 4, and then bleached by adding a bleaching agent, a bleaching stabilizer, an alkaline chemical, and a deinking agent and putting them into the alkali soaking tower 5. After performing alkali soaking with water, the ink is separated and removed by a flotation process by a floatator 6 and then dehydrated while supplying shower water 8 by a dehydrator 7 to perform washing and dehydration. It is stored in the stock tower 9 as deinked pulp (DIP). Then, it is fed from the stock tower 9 as a papermaking raw material toward the papermaking process.

  In the liner production process 11 for corrugated paper, the rejects discharged from the screen 2 and the cleaner 4 in the deinking pulp production process 10 are dehydrated by a dehydrator 12 and then passed through a slit screen 13 of 0.25 mm or less to remove dust. Processed, then dehydrated by the dehydrator 14, put into the blending chest 15, blended with other necessary raw materials, and then fed toward the paper machine of the liner for corrugated paper, Supplied to the inlet for making both.

  Further, after the reject is dehydrated by the dehydrator 12, the PH is measured by the PH meter 17, and dilute sulfuric acid 18 is added by automatic control according to the measurement result, and the PH is 7.0 to 5.5. PH adjustment is performed so as to be a predetermined value within the range.

  In this way, the reject discharged from the deinked pulp manufacturing process 10 is introduced into the corrugated paper liner manufacturing process 11 and rejected into the raw material slurry for papermaking the intermediate layer or the back layer of the corrugated paper liner or both. Is added in the range of 1 to 25 parts by weight, the rejection of the deinked pulp manufacturing process 10 can be effectively used, and earth resources can be saved and environmental destruction can be suppressed.

  In addition, in the case of acidic papermaking, the pH of the reject added to the raw slurry for producing the liner for corrugated paperboard as described above is adjusted to 7.0 to 5.5 in advance, so that the wet end of the papermaking process. There is no fear of clogging due to the precipitation of calcium carbonate, and the stability of the papermaking operation can be ensured. In the case of neutral papermaking, such PH adjustment is unnecessary. In addition, since the reject is passed through the screen 13 of 0.25 mm or less and then introduced into the blending chest 15, contamination can be reliably prevented and product quality can be prevented from deteriorating.

  Next, some examples and comparative examples of the present invention will be described. To the raw pulp from which the corrugated waste paper has been disaggregated, the reject discharged from the deinking pulp manufacturing process is added in the range of 0 to 30% by weight to prepare a raw slurry, and this raw slurry is made into a paper for a corrugated paper liner. The intermediate layer of the machine was supplied to the inlet for paper making, and the liner for corrugated paper was made with acid paper.

  In addition, as the reject, those with ash content changed to 10%, 25%, 30%, 55% are prepared and added, and the screen slit is changed to 1.5mm, 2.5mm, 3.0mm. A raw material slurry was prepared to make a paperboard liner. Moreover, at the time of acidic papermaking, the pH of the reject was adjusted to 7.0 to 5.5, but for comparison, papermaking was also performed under conditions where PH adjustment was not performed.

  In addition, the economic and environmental aspects were evaluated, and the operability and product quality at the time of papermaking were evaluated, and a comprehensive evaluation was performed based on these evaluations. Table 1 shows the amount of reject added, the ash content, the screen slit, the presence / absence of PH adjustment, and the evaluation thereof in each Example and each Comparative Example.

表１中、経済性と環境面の評価は、リジェクトを含有したものは廃棄リジェクトの有効利用によって経済性及び環境面で効果を奏するものとして、リジェクトの含有量が１％以上、１０％未満であれば○、１０％以上は◎とした。

In Table 1, the evaluation of economic efficiency and environmental evaluation is that the rejection content is 1% or more and less than 10%, as it is effective in terms of economic efficiency and environment due to the effective use of waste rejection. If yes, 10% or more was marked ◎.

The evaluation criteria for operability are
○: Draw value does not fluctuate in the press part and stable operation can be performed at the same paper making speed △: Draw value fluctuates slightly in the press part, but no change in paper making speed is required ×: Draw value fluctuation in the press part If paper production speed is not slowed down, paper breakage and quality fluctuations may occur.

In addition, the product quality is measured based on JIS P8145 by measuring the area of impurities visible in a certain area on the front and back surfaces of the manufactured corrugated paper liner.
A: 0 to 100 mm ² / m ²
○: 101-300 mm ² / m ²
×: 301 or more mm ² / m ²
As evaluated.

  In addition, in the overall evaluation, the evaluations described above were evaluated as ◎ for ◎ and ○, × for at least one ×, and ○ for the others.

  From Table 1, Examples 1 to 3 show good effects in terms of economy and environment without adversely affecting operability and product quality by adding 1 to 25% by weight of rejection, so the overall evaluation is good It is. On the other hand, since Comparative Example 1 corresponding to the conventional example does not add a reject, the economic and environmental effects cannot be obtained, the overall evaluation is poor, and on the contrary, a comparative example in which 30% by weight of the reject is added. In 2, since the operability deteriorates and the product quality also deteriorates, the comprehensive evaluation is poor. In addition, in Examples 1 to 3, Example 2 added 1% by weight compared to Example 1 added 10% by weight has relatively low economic and environmental effects, and 25% added by weight. In Example 3, the operability tends to be slightly unstable.

  Further, in Examples 4 and 5, the ash content was changed to 10% and 30% with respect to Example 1 having an ash content of 25%. In Example 5 where the ash content is as high as 30%, the product quality can be maintained, but the operability tends to be slightly unstable. On the other hand, in Comparative Example 3 in which the ash content exceeds 55% and 55%, both the operability and the product quality deteriorate, and the comprehensive evaluation is poor.

  Moreover, in Example 6, although the screen slit was changed into 0.25 mm with respect to Example 1 whose screen slit is 0.15 mm, operability and product quality can be maintained. On the other hand, in Comparative Example 4 in which the screen slit is 0.3 mm, impurities are conspicuous in the product, and the product quality cannot be ensured, so the overall evaluation is poor.

  Further, in Example 7, the other conditions were the same as in Example 1 where the PH adjustment was performed, and the PH adjustment was not performed, but only a tendency that the operability was slightly unstable was recognized. The overall evaluation was judged to be good for the time being. On the other hand, compared with Example 1, the operability deteriorated in Comparative Example 5 in which the pH was not adjusted under the conditions where the reject content was increased to 25% by weight and the ash content was increased to 30%. Is bad.

  In the present invention, since the reject discharged from the deinked pulp manufacturing process is contained in the intermediate layer and the back layer of the liner for corrugated cardboard in an amount of 1 to 25% by weight, the effective use of the reject is achieved. Moreover, it is possible to suppress environmental destruction and is useful for both deinked pulp and corrugated paper.

It is explanatory drawing of the deinking pulp manufacturing process and intermediate liner manufacturing process in one Embodiment of this invention.

Explanation of symbols

10 Deinked pulp manufacturing process 11 Corrugated paper liner manufacturing process 13 Screen

Claims (5)

  A liner for corrugated paper in which a surface layer, one or a plurality of intermediate layers, and a back surface layer are laminated, and rejects discharged from the deinked pulp manufacturing process are added to the intermediate layer and / or the back surface layer in an amount of 1 to 25 A liner for corrugated paper, characterized by containing in the range of% by weight.   The liner for corrugated paper according to claim 1, wherein the ash content of the reject is 50% or less.   Adding 1 to 25% by weight of rejects discharged from the deinked pulp manufacturing process to the pulp material of the intermediate layer and / or the back layer of the liner for corrugated paper, and paper making the liner for corrugated paper A method for producing a liner for corrugated paper.   The method for producing a liner for corrugated paper according to claim 3, wherein the pH of the reject is adjusted to 7.0 to 5.5 at the time of acid papermaking, and then the reject is added to the pulp raw material. The method for producing a liner for corrugated paper according to claim 3 or 4, wherein the reject discharged from the deinked pulp production process is treated with a slit screen of 0.25 mm or less and thereafter the raw material slurry is blended.

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