WO2010093220A2

WO2010093220A2 - Method for manufacturing tissue using recovered paper from corrugated fiberboard as raw material

Info

Publication number: WO2010093220A2
Application number: PCT/KR2010/000949
Authority: WO
Inventors: 김광호; 백기석
Original assignee: 주식회사 쌍용씨앤비
Priority date: 2009-02-13
Filing date: 2010-02-16
Publication date: 2010-08-19
Also published as: KR100957650B1; WO2010093220A3

Abstract

A method for manufacturing tissue using recovered paper from corrugated fiberboard as raw material is provided. A method for manufacturing tissue using disclosed recovered paper from corrugated fiberboard as raw material comprises: (a) a step of inputting recovered paper from corrugated fiberboard into a pulper and dissociating fibers in weak alkali condition using sodium hydroxide, (b) a step of removing foreign materials of high concentration or large size in a cleaner or screen, (c) a step of removing foreign materials in a first double nip thickener through decompression dehydration, (d) a step of generating friction between fibers in a kneader, in which the foreign materials of high concentration or large size are removed, to disperse ink embedded in the fibers, (e) a step of removing ink particles in a flotator using air bubbles through flotation, (f) a step of removing low concentration or fine foreign materials in the cleaner or screen, (g) a step of removing fine foreign materials in a second double nip thickener through decompression dehydration, and (h) a step of inputting dye for dyeing to make the fiber a raw material of tissue level. The foreign materials are removed from primary white water using a first dissolved air flotation tank, which is dehydrated in step (C). The foreign materials are removed from secondary white water using a second dissolved air flotation tank, which is dehydrated in step (g). The white water through the first and second dissolved air flotation tanks can be recycled as dilution water. In addition, the present invention is able to produce an environmentally-friendly product since bleaching is not performed during the manufacturing process. Also, the present invention contributes to cost reduction by saving the bleaching agent and preventing loss of raw materials. Single fiberizing and fines content reduction not only enhance product strength, but foreign materials such as pitch, ash, ink, flake and waste synthetic resin are also removed through a serial screening process. Therefore, raw materials of tissue level minimizing problems during post-process can be made.

Description

Manufacturing method of tissue using corrugated cardboard as raw material

The present invention relates to a method for producing tissue using corrugated cardboard as a raw material, and more particularly, by adding a dyeing process instead of removing a bleaching process in a tissue manufacturing process by recycling corrugated cardboard. The present invention relates to a method for producing tissue using corrugated cardboard as a raw material which can not only increase production quality but also reduce contaminants.

Natural pulp and recycled paper (referred to as Goji) are mainly used as raw materials for tissue production, and natural wood pulp is soft wood bleached kraft pulp (SW-BKP) and hard wood bleached kraft (HW-BKP). Pulp), UKP (Unbleached Kraft Pulp), and the like are used, and used as a corrugated cardboard notice, office paper, corrugated cardboard notice, magazines, paper bags or envelopes.

In the case of tissue companies that use paper as a raw material for tissues, the paper is made of fiber using a pulp (a device that stirs the paper together with water to remove ink from the paper or adds a whitening agent). From the cleaner and the screen (an apparatus for centrifugally removing heavier materials than the fiber material), dust removal treatment of extra materials such as hardware and plastic is carried out. Thereafter, the bleaching tower is subjected to a bleaching process using a constant temperature, concentration, time, pH, and bleaching agent to raise the raw material to a certain level or more. Then, the ink is removed from the fiber material with a flotator (a device that blows air into the liquefied fiber material to float the ink together with the bubbles to separate the ink from the fiber material), and the thinner (presses the fiber material to dehydrate it). The raw material is used as raw material for papermaking process after dehydration by means of a device. When using a series of raw material composition process, the ligrin component impregnated in the fiber is removed in the bleaching process, which is not economical due to the high loss of raw materials, and it is not environmentally friendly because it uses chlorine-based bleaching chemicals. Fibrosis and an increase in fines occur, causing problems such as dehydration deterioration and refining energy increase due to a decrease in strength during the papermaking process.

In general, corrugated cardboard is a tissue-grade raw material because it has a high kappa content containing a large amount of lignin, which is not suitable for use as a tissue material without a series of bleaching processes. Therefore, in order to show high whiteness, one of the characteristics of tissues, the method of increasing the whiteness of raw materials using bleaching chemicals is used.Bleaching chemicals such as chlorine, hypochlorite, chlorine dioxide and hydrogen peroxide are used as the bleaching chemicals. , Reducing bleach, sulfite gas, sulfite, bisulfite, hydrosulfite and the like are used.

Hydrogen peroxide is mainly used to oxidize and bleach mechanical pulp such as newspaper waste paper, and sodium hypochlorite is mainly used to bleach chemical pulp such as white paper waste paper. Other FAS and sodium hydrosulfite are used in chemical pulp as well as mechanical pulp. FAS has a strong bleaching power compared to sodium hydrosulfite, but it is expensive. If the corrugated cardboard contains paper colored with a yellow direct dye, additional reduction bleaching with sodium hydrosulfite may be performed after the oxidative bleaching treatment.

However, in the case of the bleaching chemical used as an oxidizing bleach, it has a disadvantage that it is not environmentally friendly because it is a chlorine-based bleaching method, and such a bleaching process is modified such as short fiber, increase of microfiber, and the like of cellulose fiber used as a tissue material. It has the disadvantage of lowering the yield due to the deformation of the cellulose fiber properties and the loss of the ligrin component, and the whiteness is remarkably dropped when the bleaching process is not performed, it is impossible to use as a tissue-grade raw material.

In addition, the corrugated cardboard contains a large amount of foreign substances such as pitch, ash, ink, flake and waste synthetic resin, and if not removed, it causes various problems in the subsequent process. Pitch adds contamination to the wire, felt, and Yankee dryers in papermaking processes, causing problems such as dehydration, hole generation, and poor clipping, and cannot be used as tissue grade raw materials. It causes defects and paper breaks, and in particular, prevents voids between wires and felts, leading to an increase in manufacturing costs due to poor bonding and a decrease in lifespan due to dehydration, and inks cause problems such as whiteness and spots on the product. In the case of Flake, it causes problems such as the occurrence of breakage by being stuck in wire or felt. Therefore, in the process of using corrugated cardboard as a main raw material, it cannot be used as a tissue-grade raw material without going through a series of selection processes, such as cleaners, screens, and plotters.

Paper companies that use corrugated cardboard as their main raw materials are those that produce liner paper. Unlike liner tissue, liner paper does not require bleaching because it does not need to increase whiteness, but such liner companies do not have a plotter facility for selecting pitches, and screen equipment has a lot of differences in raw material selection conditions from toilet paper factories. In the paper making process, neutral or alkaline raw materials are subjected to sizing treatment through rosin and alarm during sizing to give water resistance to the inside of paper. Pitch components are aggregated in corrugated cardboard due to pH conditions and have problems due to the pitch in paper machines. Unlike the thin paper, the basis weight of the base paper is higher than 75 gsm, so the problem due to the pitch does not stand out.

In addition, the cleaner facility has many differences from the toilet paper factory, so the ash removal efficiency is low, so that the ash content is generally formed in the liner with 5% or more and 15% or less, and it is selected for tissue grade raw material composition in the foreign matter selection process such as pitch and ash. There is a big difference from the process.

On the other hand, referring to a conventionally published patent document is as follows. Korean Patent No. 244,421 uses high quality raw materials having low kappa value and high whiteness as raw material conditions, pretreatment of raw materials under alkaline conditions by raw material processing process, decompression blowing, flotation, and centrifugal cleaning after stirring It is described about going forward. However, the Korean Patent has a technology for a process of upgrading a low quality raw material having a high kappa value and a low whiteness such as corrugated cardboard by inserting a white water selection process to remove foreign substances in a white water system using a pressurized floatation tank and dyes. Is not.

Japanese Patent No. 2987272 discloses mixing cardboard waste paper with an aqueous liquid, separating fibers at 65 ° C, and removing large or fine foreign substances using various cleaners and screens. The process of removing the ink particles and the white water selection process of removing foreign matter in the white water system by using a pressurized floatation tank are not described. In addition, Japanese Laid-Open Patent Publication No. 15-171889 discloses the contents of alkaline cooking treatment of low kappa value and high whiteness high quality office waste paper, and the process of kneading and removing ink from alkali-treated recycled pulp slurry, but the cleaner Alternatively, the process of removing foreign matters using a screen and the white water selection process of removing foreign matters in the white water system using a pressurized floatation tank, and the addition of dyes and high quality raw materials with high kappa value and low whiteness such as cardboard There is no description of the process to proceed with the work to make it.

In addition, US Pat. No. 5,348,620 discloses office waste paper in pulper and pulp with water, and removes large or fine foreign matter using a cleaner, screen, plot, press, etc., and uses ink to remove ink particles using a double nip thinner. Although the removal is described, white water selection process that removes ash, fine, and pitch that are unnecessary for thin paper raw material composition, and removes foreign substances in white water system by using double nip thinner for the purpose of toilet paper grade and pressurization. And it is not described that the operation to make a high-quality raw material of the corrugated cardboard is a low-quality raw material having a high kappa value and low whiteness by adding a dye.

According to the above-mentioned conventional patent documents, the waste paper cardboard is put together with dilution water, such as water, into a pulper and subjected to cooking in a mild atmosphere in an alkaline state, and then, such as a cleaner, a screen, a floater, a double nip thinner, or the like. Particles are removed through fine foreign material removal devices, and a process of changing a color or increasing whiteness by adding a dye during the process is described. However, in the above documents, the content of the bleaching process is generally described in order to increase the whiteness of the fiber, while the content of the bleaching process is not separately described by performing the dyeing process.

In addition, the process of resupply through the reprocessing of dehydrated white water in an apparatus such as a double nip seeker is not specifically described. The white water used in the waste paper recycling process is continuously introduced with foreign matters. If it is not properly treated, it may cause problems of the entire white water resupply system, cause water pollution, and reduce productivity. There is.

The present invention is to solve the above problems, by removing the non-friendly, low-bleaching process to minimize the deformation of the raw material and to improve the strength of the product as well as through the dyeing to enable the production of tissue-grade raw material under low whiteness Various colors can be made, and through a series of selection processes, it aims to provide a method for producing tissue paper made of corrugated cardboard by removing foreign substances such as pitch, ash, ink, flake and waste synthetic resin.

According to an aspect of the present invention, there is provided a method for producing a tissue using corrugated cardboard as a raw material according to one aspect of the present invention. (A) Dispersing fibers in a weak alkali state using a caustic soda and pulp. Step, (b) after the step (a), to remove the high concentration foreign matter or large foreign matter from the cleaner or screen, (c) after the step (b), the foreign matter by using depressurized dehydration in the first double nip thinner (D) dispersing the ink embedded in the fibers by friction between the fibers from which the high concentration or large foreign matter is removed from the kneader, after (d) the step (c), Removing the ink particles by using a floating flotation method using air bubbles in the floater, (f) after the step (e), the low concentration foreign matter or fine foreign matter in the cleaner or screen Removing, (g) removing the foreign matter by vacuum dehydration in the second double nip thinner after the step (f), and (h) after the step (g), the fibers are subjected to tissue grade Including the dye for dyeing to the composition, and the first white water dehydrated in the step (c) using a first pressure relief tank to remove foreign matters, and the dehydrated in step (h) The second white water is used to remove foreign substances by using the second pressurization tank, and the white water passed through the first and second pressurization tanks is recycled to dilution water.

The step (b) may include using a high-density cleaner for removing high concentration foreign matter using centrifugal force, and using a hole screen for removing huge foreign matter by dividing the foreign matter into sizes.

The step (b) may be performed by using a high-density cleaner for removing high-density foreign substances with a specific gravity greater than 1 by using a centrifugal force, and using a screen using holes of 1.3 mm or more and 1.8 mm or less.

The step (g) may include using a slot screen for removing fine foreign matter by classifying foreign matter into sizes and using a low density cleaner for removing low concentration foreign matter using centrifugal force.

The step (g) uses a screen using a slot having a size of 150 μm or more and 300 μm or less for removing fine foreign matters by classifying foreign matters and a low density cleaner for removing low density foreign substances having a specific gravity of 1 or less using centrifugal force. It can be made of the step of using.

The method of manufacturing the tissue is characterized in that it further comprises the step of adding a fixing agent to support the dye is colored on the fiber after the step (h).

The dye in step (h) may be any of natural dyes or synthetic dyes including vegetable dyes, animal dyes, direct dyes, acid dyes, basic dyes, and cationic dyes.

The dye may be liquid.

The step (h) is a step of maintaining the concentration of the corrugated cardboard raw material at 1% or more and 5% or less, injecting the dye at a concentration in the range of 1% or more and 8% or less than the total fiber and the dye in the fiber It may include the step of setting the holding time in the range of 5 minutes or more and 20 minutes or less to ensure that the color is stably.

The fixing agent may be determined in a concentration range of 0.2% or more and 2% or less so that the dye is easily colored in the raw material.

In the case of the fixing agent, the charge density may be high and the molecular weight may be low so that the residual dye particles may be fixed to the raw material.

In at least one of the above-mentioned (c) and (h) step, the flocculation and coagulant treatment is performed to remove fine foreign matters, thereby forming waste water. The concentration can be maintained in the range of 0.03% or more and 0.3% or less.

The white water may be added to the pulper in step (a) or may be used as a dilution white water for concentration control by adding to the flotator in step (e).

Between the step (c) and the step (d), the step of dehydrating through a separate pressure dewatering device to increase the concentration of the fiber may be further included.

The pressurized dewatering device removes impurities (colloids) through high concentration at a concentration of 20% or more and 25% or less with respect to the feedstock introduced based on a pair of rollers of the fixed roll and the driving roll, or after the pressure dewatering. It is applied to increase the reaction efficiency of the chemicals in the process, the operating conditions of the pressure dehydration apparatus can be adjusted to more than 2.5kgf / cm2 or more 3.0kgf / cm2.

The tissue may be a towel.

The manufacturing method of the tissue using the corrugated cardboard as the raw material of the present invention as described above is possible to produce environmentally friendly products by not bleaching in the processing process, contribute to cost reduction by reducing bleaching chemicals and preventing the loss of raw materials, In addition to increasing the strength of the product due to short fiber and reduced fines content, foreign matters such as pitch, ash, ink, flake and waste synthetic resin are removed through a series of selection processes to minimize problems in subsequent processes. Tissue grade raw material composition is possible

In addition, corrugated cardboard contains ligrin, and corrugated liner uses yellow dye to match the color, so it is dark brown when using corrugated cardboard as a raw material of tissue grade. As it is not suitable for use as a tissue grade, it is possible to develop products of various colors by dyeing under low whiteness to be used as tissue grade.

In addition, the manufacturing method according to the present invention can be used by simplifying the process by eliminating the bleaching process of the conventional tissue grade raw material composition, so if the dyeing proceeds without the need for additional equipment can remove the preliminary tube of corrugated cardboard notice image for recycling There is an advantage to manufacture a tissue that can be reconsidered.

In the present invention, the white water is continuously recycled to the dilution water by using a pressurized incubation process such as DAF treatment, thereby increasing the whiteness through removing foreign substances such as pitch, ash, and fine, which are not suitable for tissue grade raw materials. In addition, it is possible to reduce the use of fresh water, such as tap water and ground water to prevent the accumulation of water pollutants. In addition, when the fine foreign matter is removed using the DAF treatment process, the whiteness is increased, leading to a reduction in the amount of bleach used and the reduction of pulp contamination in the subsequent process. In other words, it is possible to prevent the additional chemicals to be introduced in order to improve the process, such as reducing the amount of felt cleaner used, thereby increasing the competitiveness in terms of manufacturing cost.

1 is a conceptual diagram of a method for producing tissue using a corrugated cardboard as a raw material according to the present invention, and

Figure 2 is a flow chart showing the flow of the main process in the manufacturing method of the tissue paper corrugated paper according to the present invention.

110:

pulp

111, 112, 113, 114, 116: dilution tank

117: first pressure injured 118: second pressure injured

122: high density cleaner 124: low density cleaner

132: hall screen 134: slot screen

142: first double nip thinner 143: first drain flow path

144: second double nip thinner 145: second drain flow path

146: Lower 150: Floatator

152: pressurized dewatering device 160: raw material final storage tank

170: dye supply pump 180: fixer supply pump

The above objects, features and other advantages of the present invention will become more apparent by describing the preferred embodiments of the present invention in detail with reference to the accompanying drawings. Hereinafter, with reference to the accompanying drawings will be described in detail a method of manufacturing a tissue using a corrugated cardboard as a raw material.

Hereinafter, 'high concentration foreign matter' means Flake and waste synthetic resin having a specific gravity greater than 1, and 'huge foreign matter' may be defined as meaning the foreign matter by 1.0 mm or more by dividing the foreign matter by size. On the other hand, 'low concentration foreign material' means Flake and specific gravity of less than 1 specific gravity, waste synthetic resin, etc., 'fine foreign material' is divided into the foreign matter by the size of less than 1.0mm in diameter, more specifically in the range of 150 ~ 300㎛ It can be defined as meaning.

In addition, what is expressed only as a foreign matter below can be understood as a concept including both the high concentration, low concentration foreign matter and the large, fine foreign matter.

1 is a conceptual diagram of a method for producing tissue paper from corrugated cardboard according to the present invention, and FIG. 2 is a flowchart illustrating a main process flow in the method of manufacturing tissue paper from corrugated cardboard according to the present invention.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

In the present invention, tissue can be produced using only corrugated cardboard (OCC, Old Corrugated Containers) as a main ingredient. Hereinafter, all ratios including percentages are by weight unless otherwise stated in the present invention, and the chemical ratios may be based on oven dry weight of cellulose fibers. When specifying the pH of the corrugated cardboard slurry to which the process is performed, unless otherwise indicated, the initial pH at the time of producing the corrugated cardboard slurry is shown. On the other hand, in general, professional tissue manufacturers are used to classify tissue into roll tissue (bathroom tissue), cosmetic tissue (facial tissue), and towel (kitchen towel).

First, it cuts the collected corrugated cardboard bundles and is divided into the size enough to be put into the pulper 110, a steamer. Here, the dissociation of the fibers contained in the corrugated cardboard is promoted, and the pulping process is performed in a weak alkali state using caustic soda to separate the pitch and the ink components attached to the corrugated cardboard. Pretreatment of the cut corrugated cardboard with mild alkali (NaOH) is intended to activate the lignin content of the fibers and to swell the lattice of the fibers to better adapt to the cooking process in the pulping process in the present invention.

Looking at the waste fibers from the corrugated cardboard, the lignin content of Ka # of 60 or more is generally and typically maintains 100 or more, the pitch content of 1% to 5%, the ash content of 10% to 30% The content of the ink is maintained at 400ppm to 800ppm, the content of Flake is contained 3% to 10%, the waste synthetic resin content is 1% to 3%. As described above, a fiber having a high kappa value and containing a variety of foreign substances which cannot be used as a raw material of tissue grade is inadequate for producing high quality tissue, and thus has a raw material composition of tissue grade through a series of selection processes as in the present invention. It can help to remove unnecessary foreign substances.

In the pulping process, the raw material, that is, the concentration of the corrugated cardboard input is preferably in the range of 5% or more and 15% or less, and caustic soda (NaOH) compared to the total raw material to meet weak alkali conditions in order to promote dissociation of the raw material. To maintain a concentration within 1%. In this state, the operation time of the pulper 110 is operated in the range of 30 minutes or more and 120 minutes or less.

The foreign matter content of the corrugated cardboard used as an example in the present invention is shown in Table 1 below.

Table 1

Foreign substance content	shame
Pitch (%)	1.95
Ash (%)	16.18
Ink (ppm)	526.84
Flake (%)	5.84
Waste synthetic resin (%)	1.26

* The ink content used ERIC (Effective Residual Ink Concentration) Value using Color Touch 2.

In addition, the physical properties of the corrugated cardboard used as an embodiment in the present invention are shown in Table 2 below.

TABLE 2

Physical properties	shame
Pulping Yield (%)	98.38
Floating yield (%)	91.07
Fiber length (um)	992
Whiteness (ISO)	30.90
Thermal insulation (m)	3918
Yeosu-do (CSF)	428

In the pulp 110, the fiber material contained in the corrugated cardboard is changed into a sufficiently swollen state, and then passes through the first dilution tank 111 before moving to the high density cleaner 122. In the first dilution tank 111, A process of diluting the concentration of the raw material for preparing the tissue to a concentration of 3% or more and 5% or less is performed.

After passing through the high-density cleaner 122 after the dilution process, the high-density foreign substances having a specific gravity greater than 1 are removed by centrifugal force. More specifically, the kind of foreign matter to be removed is removed in the range of 1% or more and 5% or less with a specific gravity of more than 1 Flake, waste synthetic resin, etc., wherein the differential pressure between the inlet and the outlet of the high density cleaner 122 is 0.5 kpa or more. It is preferable to exist in the range of 1.0 kpa or less. As described above, the high-density cleaner 122 is a device that uses specific gravity of materials, and materials such as wire and stone blocks are processed in such a manner as to remove other than fibers by providing centrifugal force using properties that are heavier than fibers.

After the foreign matter is removed using the specific gravity in the high-density cleaner 122, the hall screen 132 to separate the foreign matter by the size to remove the giant foreign matter 1.0 mm or more in diameter. More specifically, the foreign substances to be removed in detail are rigid fibers having low fiber flexibility such as Flake and wood flour having a diameter of 1.0 mm or more, and their content is removed within a range of 1% or more and 5% or less. In this case, screens with hole sizes of 1.0 mm or more and 1.5 mm or less can be used. In addition, in order to select usable fibers of the tissue grade, the fiber length which has a bad influence on the touch by improving the strength of the tissue is 1.8 mm or more. It is preferable to use a hole size in the range of 1.3 mm or more and 1.8 mm or less in order to eliminate the problem. In addition, it is preferable that the differential pressure between the inlet and the outlet of the hall screen is operated in a range of 0.5 kpa to 1.2 kpa.

The high-density cleaner 122 may be provided with a separate filter (not shown) capable of removing and removing contaminants. A separate filter member may also be installed in the slot screen 134, the low density cleaner 124, and the flotator 150, which will be described later.

The first double nip sealer 142 disposed at the rear end of the hole screen 132 gives a rotational force of 720 RPM or more at the roller, and thus, primary dehydration is generated by the first centrifugal force. Ash and pitch components are removed and the foreign matter content is removed within 1% to 5% of fine fibers, Ash is removed within 1% to 5%, and pitch is removed within 0.2% to 0.5%. After the first dehydration by centrifugal force, the second dehydration, which is concentrated under pressure by the linear pressure of the drum and the wire, is generated to remove moisture. The dehydration process may be adjusted in a range of 10% or more and 15% or less in order to remove fine foreign matters such as pitch, fine, talc and the like using high speed rotation. Preferably, after passing through the first double nip thinner 142, the discharge concentration of the stock may be maintained at 15%. The first double nip seeker 142 is provided with a first drain flow passage 143 to discharge the dehydrated liquid.

The primary white water dewatered from the first double nip thinner 142 flows through the first drain flow path 143 to the first pressurization tank 117, where most colloidals to be removed have anions. In addition, a layer of cations is formed around the particles, and the repulsive force between the particles is stronger than gravity, and the particles remain suspended. After the colloidal component of 1um or less is increased through the first anionic coagulant treatment, the floc size of 1mm or less is increased, and after the secondary cationic coagulant treatment, the microfibers, ash, and pitch form the flocs, and then fine air bubbles It is sent to the wastewater treatment plant through the injury through, where the fine content of the wastewater is more than 90%, the ash content of the fine content is more than 70%, the pitch content is preferably more than 0.5%, and after removing the foreign matter 1 It is preferable to maintain the concentration of the tea white water in the range of 0.3% or more and 0.03% or less in order to prevent the re-introduction of ash and pitch in the stock.

As described above, the first pressure flotation tank 117 is used for the purpose of removing only foreign substances such as talc and fine fibers in the primary white water. Through such use, it is possible to secure a certain level of whiteness even without a bleaching process. And repeated use of dilution water is possible. In the present invention as the pressure flotation tank 117, the process can be performed using a dissolved air flotation (DAF) treatment method. The chemicals used in the DAF treatment process of the present invention are different from the chemicals used in the pressurization tank used in the existing wastewater treatment apparatus, and the recovery of fibers and the water pollutants through the white water treatment in the raw material selection process, not the wastewater treatment. It is applied in the process to remove the wastewater and it is completely different from the DAF treatment for the conventional wastewater treatment.

Here, the foreign matter removal efficiency and the whiteness increase effect according to the application of the coagulant and the flocculant in DAF are shown in Table 3 below.

TABLE 3

Line		Before drug treatment					After drug treatment
		density	efficiency	Ash	efficiency	Whiteness	density	efficiency	Ash	efficiency	Whiteness
DAF # 1	In	0.3938	33.1%	64.0427	5.5%	78.1%	0.2873	91.9%	58.6167	71.3%	78.8%
	Out	0.2636		60.5283			0.0234		16.8044
DAF # 2	In	0.2472	12.1%	49.9191	2.3%		0.1804	29.6%	42.2427	5.3%
	Out	0.2174		48.7580			0.1271		40.0018

In addition, the DAF treatment process in the present invention, while treating the foreign matter to form a tissue-grade raw material to move to the waste water treatment plant, in the case of the DAF treatment process used in other industries, in order to recycle the raw material by mixing in the middle layer to increase the yield Since the use of the DAF process of the present invention, the use of the present invention increases the efficiency of removing foreign matters to prevent the occurrence of problems in the papermaking process of toilet paper manufacturing, and also significantly increases the cost of bleaching and cleaning chemicals through DAF treatment.

The first white water sent from the first pressurization tank 117 to the first white water reservoir 127 is transferred to the pulper 110, the high density cleaner 122, the hole screen 132, and the first double nip seeker 142. Each predetermined amount is supplied periodically for concentration adjustment. The first pressurizing tank 117 allows the first white water to be continuously circulated through this process, thereby allowing the repeated use of the dilution water in the process of manufacturing the tissue.

The stock discharged from the first double nip sealer 142 is introduced into the pressurized dewatering device 152 to continue the process. The pressurized dewatering device 152 is a mechanism for removing particles and contaminants, which may be referred to as Shiborera, and removes impurities through a pressurization process against a material introduced on the basis of a pair of rollers of a fixed roll and a driving roll. Perform the process to remove it. The pressurized dewatering device 152 is applicable to remove impurities (colloids) through high concentration or to increase the reaction efficiency of the chemical in the process after pressurized dehydration. The operating conditions of the Shiborera can be adjusted to pressurization of 2.5kgf / cm2 or more and 3.0kgf / cm2 or less, in special cases can be operated by setting the 2.8kgf / cm2 to Center-Line, the total concentration of the dehydrated raw material is more than 20% 25 It is kept in the range of% or less. In order to prevent loss of raw materials and to remove colloidal particles, the wire mesh of the fixed roll is preferably a first 8 mesh and a second 30 mesh, and the wire mesh of the press roll is preferably a first 8 mesh and a second 20 mesh. At this time, foreign matter of the size range of more than 0.1 10um is removed. The primary white water dewatered from the pressure dewatering device 152 may be introduced into the first pressure flotation tank 117 and undergo a process of removing fine foreign matter again.

A kneader (146 kneader) is a device that disperses and undifferentiates ink and pitch that are embedded in a fiber by causing friction between fibers. While rotating at a speed, there is a roller type for stirring and mixing a high viscosity material between the rollers, or a stirring arm for stirring the material in the device slowly with a stirring blade of a furnace type or an arm type, and is equipped with a heating and cooling mechanism. There is also.

In the kneading step using the kneader 146, in order to separate ink particles and pitch from the fibers and to promote micronization, the concentration of the paper passing through the kneader is maintained in the range of 20% or more and 35% or less, Has a range of 30 Ampere or more and 50 Ampere or less, and it is preferable to maintain the heating temperature in the range of 50 degrees or more and 70 degrees or less. The kneader 146 is connected to the second dilution tank 112, and serves to dilute to a proper concentration before the feed material is supplied to the floater 150.

The floater 150 disposed at the rear end of the kneader 146 removes ink particles using a floating flotation method using air bubbles. The method for removing the ink particles may include any one of enzyme deinking, neutral deinking, alkali deinking, reduction deinking, ultrasonic deinking, and ozone deinking.

Removing the ink particles by using the floater 150 is a step of diluting the concentration of the paper stock in the range of 1.0% or more and 2.0% or less, and maintaining the pH of the paper at 9 or more and 11 or less by adding caustic soda. Maximizing the floating flotation by adjusting the calcium hardness of the white water to 200 ppm or more and 600 ppm or less, and adding a deodorant to 0.02% or more and 0.10% or less to disperse the ink particles from the fibers or to plot the ink particles. And forming air bubbles to float the ink particles.

Here, the caustic soda is added to adjust the pH of the paper so that caustic soda is added at a concentration of 1% relative to the total dry fiber to maintain a proper pH. In addition, the flow volume of air can be set to 7 L / min. At this time, the ink to be removed is removed within a range of 200 ppm or more and 500 ppm or less, and the pitch is removed within a range of 0.5% or more and 1% or less.

At this time, the data on the change in the effluent efficiency and the whiteness according to the amount of deodorant is shown in Table 4.

Table 4

Deodorant input (g / hr)	density(%)	Before Floatator Processing		After Floatator Processing
Deodorant input (g / hr)	density(%)	Ink particles (ppm)	Whiteness (%)	Ink particles (ppm)	Whiteness (%)
1.2	1.41	110.9	79.46	76.7	81.58
1.5	1.43	122	78.84	89.8	81.69
1.8	1.35	146.2	76.71	105.3	80.31
2	1.42	150.1	75.69	110.8	79.17

The raw material having passed through the floater 150 passes through the third dilution tank 113 and passes through the slot screen 134 to remove sticky foreign matters and fine foreign matters of 150 μm or less. In the slot screen 134, the slot size of the screen may be within a range of 150 μm or more and 300 μm or less in order to efficiently remove fine foreign matter. In particular, the slot size is preferably operated to 150 μm or less for removing sticky. Adjustment of the slot size may be made by adjusting the size of the slot formed in the Psv Basket disposed therein. In other words, through the process of adjusting the slit size, it is possible to stabilize the quality by improving the removal of foreign substances by increasing the open area and to create an environment in which lower fuel can be used.

Through the process of adjusting the slot it is possible to significantly reduce the input of the chemical for removing foreign matter. In the process by the slot screen 134, the fourth dilution tank 114 is disposed so that proper dilution is performed. At this time, the pitch content to be removed is removed within the range of 0.1% or more and 0.5% or less.

The low density cleaner 124 is disposed at the rear end of the slot screen 134, and the low density cleaner 124 removes the low density foreign matter using centrifugal force. Here, it is preferable that the pressure difference between the inlet and the outlet of the low density cleaner 124 is in a range of 0.5 kpa to 1.0 kpa, and it is preferable to keep the wearing concentration at 1% or less in order to increase the foreign matter removal efficiency. In particular, the low-density cleaner 124 is characterized in that a large portion of the fine foreign matter less than one specific gravity is removed, the kind of the foreign matter to be removed is the content of the foreign matter removed by fine stone powder, silver foil and styrofoam having a specific gravity of 1 or less. It is removed within 3%.

At this time, the foreign matter removal efficiency according to the treatment concentration of the slot screen is shown in Table 5.

Table 5

division	Treatment concentration 0.9%			1.0% treatment concentration
division	ERIC value (ppm)	Ash (%)	DCMextractives (%)	ERIC value (ppm)	Ash (%)	DCMextractives (%)
# 1 Feed	68.9	11.52	0.22	76.7	19.84	0.15
# 1 Accept	74.9	11.17	0.08	83.3	14.04	0.12
# 1 Reject	51.6	6.93
# 2 Accept	83.1	14.27		100.9	17.53
# 2 Reject	66.4	5.95		71.1	10.83
LD out	84.2	12.18	0.13	84.7	16.79	0.35

After the process of removing the low-density fine foreign matter, the second double nip thinner 144 gives a rotational force of more than 720 RPM on the rollers to generate the first dehydration by the first centrifugal force. , Ash and Pitch components are removed and the amount of foreign matter removed is removed within 1% to 5% of fine fibers, Ash is removed within 1% to 5%, and pitch is removed within 0.2% to 0.5%. . After the first dehydration by the centrifugal force is concentrated under pressure by the linear pressure of the drum and the wire secondary dehydration occurs to remove the moisture. After centrifugal dehydration, fine foreign matters contained in white water are removed and the final raw material is transferred to the final chest 160 of the raw material. At this time, the content of the foreign matter contained in the final reservoir should be less than 10% Ash, it is preferable that the pitch is within 0.5%.

The second double nip seeker 144 transfers the second white water to the second pressure floating tank 118 through the second drain flow path 145. Secondary white water dewatered in the second double nip seeker 144 moves to the second pressurized flotation tank 118 where most of the colloidal to be removed has an anion and a layer of cation around the particle The repulsion between particles is stronger than gravity, and as a result the particles remain suspended. Colloidal components of 1 μm or less are increased by the first anionic coagulant treatment, and the floc size of 1 mm or less is increased. Secondary cationic coagulant treatment is used to form the fine fibers, ash, and pitches. It is adsorbed and sent to the wastewater treatment plant through the flotation. At this time, the fine water content of the wastewater is 90% or more, the ash content of the fine powder is 70% or more, and the pitch content is preferably 0.5% or more. In this case, the concentration of the second dilution water after removing the foreign matter is the ash of Pitch and Ash. It is desirable to keep within 0.3% to 0.05% to prevent re-entry. The second pressurized floatation tank 118 may supply the second white water to the slot screen 134, the low density cleaner 124, and the second double nip thinner 144 through the second white water reservoir 128, or may have a separate flow. The white water may be directly supplied to the flotator 150 through the data white water storage unit.

In the raw material final reservoir 160, the concentration of the stock is preferably diluted to 4% or less so that the dye is uniformly dispersed in the raw material slurry.

Next, the dye is supplied to the raw material final storage tank 160 from the dye supply pump 170. Here, the input amount of the dye for dyeing the raw material is in the range of 1% or more and 8% or less, and any one of the dyes include vegetable dyes, animal dyes, direct dyes, acid dyes, basic dyes, and cationic dyes. It may include.

In the dyeing process, a liquid dye may be applied to ensure uniform dyeing. In order to help the uniform dyeing, the concentration of the stock is diluted in a range of 1% or more and 5% or more, and the retention time is kept in the range of 5 minutes or more and 20 minutes or less for the dye to be stably colored on the fiber. It may be desirable to further include the step of adding a dye and a second, in order to increase the uniformity of the dyeing.

In this case, the dye may be used in any one of yellow, blue, red, black, orange, brown, scarlet colors or in combination, and the dye input amount is added based on the 1% and 4% input of the total fiber. . In addition, the dye retention time after the dye input is maintained at a minimum of 5 minutes.

After the dyeing process is performed through the dye supply pump 170, the dye may be easily colored in the raw material through the fixing agent supply pump 180.

The fixer to be supplied is in the range of 0.2% or more and 2% or less, and it is preferable that the charge density is high and the molecular weight is low so that the residual dye particles can be fixed in a stable state in the material. Injecting the fixer may further include diluting to facilitate the addition of the high viscosity fixer and quantitatively adding the fixer. In the process according to the embodiment of the present invention, in order to increase the coloring of the dye, a retention time is given for 2 minutes after adding 0.3% and 1.5% of the fixing agent to the total fiber.

Colors after dye addition for the examples of the present invention are as shown in Table 6 below.

Table 6

division	Dye input (%)	L	a	b
Blank	NA	69.94	3.16	13.13
Yellow	One%	68.16	2.05	27.77
Red		59.35	23.21	6.88
Blue		56.77	-0.47	-3.69
Black		59.11	-1.38	5.80
Orange	4%	65.34	11.55	29.85
Brown		58.94	16.03	22.31
Scarlet		57.58	28.49	11.51
Blue		61.83	-13.90	0.44

The present invention indicates the degree of staining using the Hunter L, a, b pigment grade. L represents lightness from O (black) to 100 (white), a is red when positive, green when negative, and gray when O. In addition, b represents yellow when positive, blue when negative, and gray when O. White or near white paper will generally have an L value of at least 80 and a (a ² + b ² ) ^0.5 value of less than 10 or 10.

As shown in Table 6 above, it can be seen that the L value of the applied dye shows a distribution of at least 56.77 to at most 68.16. Although the L value in the state without dye is 69.94 shows that it is closer to white than the state in which the dye is applied, in the present invention, the dye is added to the corrugated cardboard of low whiteness to proceed dyeing. The above-described pigment grades are valuable for reference as they are characterized in producing high quality dyed paper.

Hereinafter, a method for manufacturing a tissue according to the present invention will be described with reference to FIG. 2 through a simplified flowchart.

First, the corrugated cardboard bundles are shredded into a suitable size and put into the pulper 110 (S11). Caustic soda is added to the pulp 110 to help dissociate the fibers contained in the corrugated cardboard (S12). When the dissociation of the corrugated cardboard reaches an appropriate level, the high density cleaner 122 or the hole screen 132 performs a process of removing high concentration and large impurities (S13). Thereafter, the pressure reduction dehydration process is first performed at the first double nip thinner 142 (S14). The primary white water dehydrated in the step S14 is a fine foreign matter removal operation is performed in the first pressure flotation tank (117) (S15), the storage is made in the first white water storage tank (127) (S16) the purified 1 The tea white water is re-injected into the pulper 110 to support fiber swelling in the corrugated cardboard. Here, the primary white water is not only supplied to the silk pulper 110 but may also be supplied to the high density cleaner 122, the hole screen 132, and the first double nip sealer 142.

The fiber component having passed through the first double nip thinner 142 is subjected to a process of removing foreign matter in a pressurized state while passing through a pressurized dehydrator 152 such as Shiborera. The kneading process is performed for the material supplied through the fiber to perform the function of dispersing the ink on the fiber by the friction between the fibers (S18). The dispersed ink is subjected to a process of being suspended in the floater 150 (S19).

Thereafter, a process of removing low concentration and fine impurities is performed in the low density cleaner 124 or the slot screen 134 (S20), and a reduced pressure dehydration process is performed in the second double nip thinner 144 (S21). ). The second white water dehydrated in the step S21 is made of a fine foreign matter removal operation in the second pressurization tank 118 (S22), and stored in the second white water storage tank 128 (S23). The tea white water is reinserted into the kneader 146 to support the swelling of the fibers in the corrugated cardboard. Here, the secondary white water may be supplied not only to the kneader kneader 146 but also to the low density cleaner 124, the slot screen 134, and the second double nip thinner 144.

On the other hand, the paper stock as a raw material of the corrugated cardboard, which has undergone dissociation, dilution, impurity removal, and dehydration, is finally transferred to the raw material final storage tank 160 and extracted (S24).

Thereafter, dyes of various colors are introduced into the raw material final storage tank 160 to perform a dyeing process (S25), and a fixing agent is additionally supplied to support coloring of the dye (S26).

As described above, the manufacturing method of the tissue using the corrugated cardboard of the present invention as a raw material is not bleached in the processing process, it is possible to produce environmentally friendly products, and contribute to cost reduction by reducing bleaching chemicals and preventing the loss of raw materials, Minimization of short fiber and fine content increases the strength of the product and removes foreign substances such as pitch, ash, ink, flake and waste synthetic resin through a series of selection processes, minimizing problems in subsequent processes Tissue grade raw material composition is possible.

As a result, conventional corrugated cardboard contains colored dyes and contains a large amount of foreign substances such as pitch, ash, ink, flake, and waste synthetic resins, so it is not suitable as a raw material for tissue grades, and keratinization is performed to meet the tissue grades due to lack of flexibility. As it is difficult to process the raw material with high whiteness, it can be converted into specialized paper through the dye input process and the fixing agent supply process through the selection process that can remove the foreign substances of the present invention and make it into a tissue grade raw material. There is an advantage.

In addition, it is possible to develop a product of various colors by dyeing under a low whiteness so that the corrugated cardboard with a predetermined amount of color dyes can be used as a tissue grade, the production method according to the present invention is a conventional tissue raw material composition Since the process can be simplified and used, there is an advantage in that the tissue is dyed without the need for additional equipment.

While preferred embodiments of the present invention have been described above, the present invention is not limited to the above-described specific embodiments. That is, those skilled in the art to which the present invention pertains can make many changes and modifications to the present invention without departing from the spirit and scope of the appended claims, and all such appropriate changes and modifications are possible. Equivalents should be considered to be within the scope of the present invention.

Claims

(a) injecting the corrugated cardboard into the pulp and dissociating the fibers in a weak alkali state using caustic soda;

(b) after step (a), removing the high concentration foreign matter or large foreign matter from the cleaner or screen;

(c) after the step (b), removing foreign matter by using vacuum dehydration in the first double nip thinner;

(d) after step (c), dispersing the ink embedded in the fibers by friction between the fibers from which the high concentration or large foreign matter is removed from the kneader;

(e) after the step (d), removing the ink particles by using a floating flotation method using air bubbles in the floater;

(f) after step (e), removing the low concentration foreign matter or fine foreign matter from the cleaner or screen;

(g) after the step (f), removing foreign matter by using vacuum dehydration in the second double nip thinner; And

(h) after step (g), adding a dye for dyeing the fiber to form a tissue grade raw material; and

The foreign white water dehydrated in step (c) is removed by using a first pressurization tank, and the foreign white water dehydrated in step (g) is removed using a second pressurization tank.

A method for producing tissue using corrugated cardboard as a raw material, wherein the white water having undergone the first and second pressurizations is recycled to dilution water.
The method of claim 1,

The step (b) is a corrugated cardboard raw material comprising the step of using a high-density cleaner for removing high concentration foreign matter using centrifugal force and using a hole screen for removing large foreign matter by classifying the foreign matter in size Manufacturing method of tissue to use.
The method of claim 2,

The step (b) is a corrugated cardboard notice comprising the step of using a high-density cleaner for removing high-density foreign substances with a specific gravity more than 1 by using a centrifugal force and a screen using a hole of 1.3mm or more and 1.8mm or less Process for producing tissue using as a raw material.
The method of claim 1,

The step (f) is a corrugated cardboard raw material comprising the step of using a slot screen for removing fine foreign matter by classifying foreign matters in size and using a low-density cleaner for removing low concentration foreign matters using centrifugal force Manufacturing method of tissue to use.
The method of claim 4, wherein

The step (f) is to classify the foreign matter by the size using a screen using a slot size of 150um or more and 300um or less to remove the fine foreign matter and a low-density cleaner to remove the low-density foreign matter less than specific gravity 1 using centrifugal force The manufacturing method of the tissue which used as a raw material the corrugated cardboard characterized by consisting of the steps.
The method of claim 1,

After the step (h), the fixing agent is added to support the dye to be colored on the fiber; manufacturing method of the tissue paper corrugated cardboard further comprising a.
The method of claim 1,

The dye in step (h) is a corrugated cardboard, characterized in that any one of natural dyes or synthetic dyes, including vegetable dyes, animal dyes, direct dyes, acid dyes, basic dyes, and cationic dyes Manufacturing method of tissue to say.
The method of claim 7, wherein

The dye is a liquid manufacturing method of a tissue using a corrugated cardboard as a raw material, characterized in that the liquid.
The method of claim 1,

The step (h) is a step of maintaining the concentration of the corrugated cardboard raw material at 1% or more and 5% or less, injecting the dye at a concentration in the range of 1% or more and 8% or less than the total fiber and the dye in the fiber Method for producing a tissue using a corrugated cardboard as a raw material comprising the step of setting the holding time in the range of 5 minutes or more and 20 minutes or less so as to stably color.
The method of claim 6,

And the fixing agent is determined in a concentration range of 0.2% or more and 2% or less so that the dye is easily colored to the raw material.
The method of claim 10,

In the case of the fixing agent, the tissue manufacturing method of the tissue made of corrugated cardboard as a raw material, characterized in that the charge density is high and the molecular weight is low so that the residual dye particles can be fixed to the raw material.
The method of claim 1,

At least one of the step (c) and the step (g) is the flocculation and coagulant treatment is carried out to remove the fine foreign matters to form waste water, the white water after the pressurized impregnation prevents re-entry of the foreign matters In order to maintain the concentration in the range of 0.03% or more and 0.3% or less in order to produce a tissue using a corrugated cardboard as a raw material.
The method of claim 12,

The white water is added to the pulper in the step (a) or in the step (e) is added to the floater in the manufacturing method of the tissue paper corrugated cardboard characterized in that it can be used as dilution white water for concentration adjustment.
The method of claim 1,

Method of producing a tissue using corrugated cardboard as a raw material further comprising the step of dewatering through a separate pressurized dewatering device to increase the concentration of the fiber between step (c) and step (d).
The method of claim 14,

The pressurized dewatering device is based on a pair of rollers of a fixed roll and a driving roll to remove impurities through high concentration at a concentration of 20% or more and 25% or less, or in a process after pressurized dewatering. Applied to increase the reaction efficiency of the drug, the operating conditions of the pressurized dewatering device is a method for producing a tissue of corrugated cardboard as a raw material, characterized in that the pressure can be adjusted to more than 2.5kgf / cm2 3.0kgf / cm2.
The method according to any one of claims 1 to 15,

The tissue is a manufacturing method of tissue using a corrugated cardboard as a raw material, characterized in that the towel.