JP2000136492A - Production of pure bagasse paper without using wood pulp - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide the technology enabling is to mass-produce pure paper made of 100% non-wood pulp without using wood pulp from the view point of the protection of global environment, in consideration of the fact that bagasse pulp has largely been used as a principal raw material when mass-producing pure paper made of non-wood pulp at a low cost but soft wood pulp excellent in various kinds of strength has been blended as binding pulp since conventional bagasse pulp is short of various kinds of strength. SOLUTION: This method has three processes in combination with one another: (1) cutting stems of millets diagonally and parallel to one another to subject them to sap removal and depithing so as to acquire long rinds; (2) treating the rinds with an alkaline cooking liquor to acquire pulp having various kinds of strength such as tear strength; (3) blending it as binding pulp with bagasse pulp used by the conventional method, followed by making paper.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing 100% non-wood fine paper using bagasse pulp as a main raw material without using any wood pulp in consideration of global environmental problems.

[0002]

2. Description of the Related Art Bagasse, which is a squeezed residue of sugar without using wood pulp, has been partially pulpted and used for producing paper. Even with current technology, it is possible to make bagasse pulp by using it alone. However, conventional bagasse pulp has a short fiber length and contains a lot of fine fibers, so it has poor drainage, and if beaten, it further reduces the drainage and lowers papermaking properties. Have been. Paper made of 100% bagasse pulp had low evaluation of quality such as low tear strength and various other strengths, and was not actually distributed as a commercial product. Therefore, usually, about 10 to 30% of softwood pulp having a long fiber length is blended with bagasse pulp to produce printing paper, writing paper, and other paper, and supply the paper to the market. With increasing interest in the global environment, 100% without using wood pulp
Consumers are calling for non-wood pulp paper,
Many attempts have been made to produce such papers. However, non-wood pulp having a large fiber length which can be used in place of softwood pulp has conventionally been found only in bast pulp such as mulberry or mitsumata or hemp pulp such as abaca or sisal. However, these non-wood long-fiber pulp have very few resources as resources, and are used as valuables for Japanese paper such as Kozo and Mitsumata, and as special raw materials such as securities paper such as abaca. Most of them were used, and could not be supplied as a raw material for bagasse paper on the premise of mass consumption.

[0003]

The problem to be solved by the present invention is that 100% non-wood is used as a main raw material from bagasse pulp, which is considered to have a low tear strength and other various strengths and a poor drainage obtained by the conventional method. It is an object of the present invention to provide a method for producing pulp bagasse fine paper.

[0004]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies to solve the above-mentioned problems, and as a result, have completed the present invention. That is, according to the present invention, the stems of millet such as sugar cane and sweet sorghum are cut diagonally and in parallel, and drained and depisped (medulla) to prevent long fibers (thickness) without damaging the fibers. A first step of obtaining husk) as a pulp raw material, and then the line is digested with an alkaline cooking liquid, preferably PA cooking liquid, and has good drainage properties and various strengths such as tear strength, tensile strength, burst strength and the like. A second step of obtaining a pulp having a large pulp as a connecting pulp, a third step of blending a connecting pulp with a pulp obtained by pulping bagasse by a conventional method, and a first step, a second step The combination of the third step and the third step can provide a method for producing high-quality bagasse paper without using wood pulp.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION In the present invention, a raw material plant of a pulp for connection is sugar cane or sugar solution such as sweet sorghum, and millet cultivated to obtain sugar. The millet which takes out these sugar liquids consists of a hard line (thick skin) on the outside and pis and cane juice on the inside. In the present invention, the largest millet that can be used as a raw material for pulp for strong connection is milling as a first step without crushing the mill as in a conventional sugar mill as a pretreatment. Diagonally and in parallel and cut parallel to a thickness of 3 to 60 mm, preferably 6 to 30 mm.
By separating and removing the fibers, long millet fibers can be extracted as a long pulp without hurting as a long pulp raw material. This is because even if the stem is cut diagonally to the same thickness of 30 mm, the line length obtained by cutting the stem at right angles is 30 mm.
When cut to °, the thickness of the stem is 30 mm and the length is 60 mm, and when cut to 20 °, the thickness is 30 mm and the length is 88 mm
The effect is also explained.

[0006] The sugar solution and the scum (bagasse) are separated from the stem stem cut diagonally, and the line and pis are further separated and collected from the bagasse. A compression desiccant apparatus such as a roll press used in the above is most suitable for squeezing, and a counter-current washing function and a diffuser for washing bagasse and collecting residual sugar.
The device can be used efficiently. Highest quality brown sugar can be obtained from the sugar solution that is the most squeezed. In addition, since the thin but colorless and transparent recovered sugar solution has a small amount of non-fermented components, if used for the production of yeast or the like, the waste water contains few non-fermented components and can reduce the environmental load. For this reason, it is much more environmentally friendly than conventional yeast culture using dark brown molasses having a very high content of non-fermented components. Separation of line and pis in the pomace of the present invention can be easily performed by a dry method or a wet method. Lined has good drainage and is a raw material for pulp with high tear strength and various strengths. This is because, in the conventional method, when squeezing the sugar liquid from sugar cane, both the line in bagasse and the pices are crushed like rice hulls, and fine fibers that can be called the third intermediate component are formed.
It can be explained that it is difficult to separate only coarsely ground lines into finely ground lines and pis, and the resulting pulp also contains many fine fibers, has poor drainage, and has a small strength including tear strength.

In the second step of cooking with an alkaline cooking liquor, an AP using an aqueous solution containing only caustic alkali as the cooking liquor is used.
And a KP method and a PA (hydrogen peroxide-alkali method) method using a mixture of caustic alkali and alkali sulfide as a cooking chemical. The PA method is a pulping method in which at least one or more of the following cooking aids is added to an alkaline solution of hydrogen peroxide to prepare a cooking chemical liquid.

[0008] Examples of the cooking aid in the PA method include a chelating agent, anthraquinones, a magnesium compound, a polar temporary solvent that can be arbitrarily mixed with water, and oxygen if desired. The alkaline solution used in the PA method is a hydroxide of potassium or sodium, and it is more desirable that the carbonate thereof coexist. The amount of the alkali (hereinafter referred to as the absolute dry weight of the raw material line) is 13 to 30%, preferably 17 to 22% in terms of Na2O, and the causticization ratio is 50 to 95%, preferably 70 to 85%. Due to the coexistence of carbonate, damage to the fiber is small, and a high pulp yield can be expected. The amount of peroxide used to release hydrogen peroxide when injected into water such as hydrogen peroxide or percarbonate is 0.5 to 15% in terms of H2 O2.
And preferably 1.0 to 5%. The amount of the cooking aid used varies depending on the type of auxiliary, but the amount of the chelating agent is 0.02-
1%, anthraquinones are 0.003 to 1%, magnesium compounds are 0.05 to 0.5%, and polar organic solvents arbitrarily mixed with water are 0.02 to 1%.

[0009] In the digestion of lined by the PA method, the lined and the cooking liquid of the PA method (optionally pressurized with oxygen) are added to a vessel made of a material such as stainless steel that can withstand contact with hydrogen peroxide. . Cooking temperature is 90 ~ 180 ℃,
Preferably 110-150 ° C, digestion time 10-360.
Minutes, preferably 20 to 120 minutes. The liquid ratio is 3 to 12 L / kg for liquid phase cooking and 1.2 to 3.0 L / kg for gas phase cooking.
kg. According to the gas-phase cooking, it is possible to reduce the steam intensity, and it is possible to collect the pulp waste liquid at a high concentration, so that it is possible to reduce the size of a concentrating device and the like, and to reduce the amount of steam for concentration. It is environmentally friendly and economically advantageous. According to the PA method, the pulp obtained is A
The yield is higher than the P method, the strength is superior, and the KP method does not generate odor, and environmental measures are extremely easy.
Since the pulp yield is high, the color of unbleached pulp is much lighter and bleaching is easy, it is extremely advantageous for the production of high quality paper and the like.

The making of bagasse high-quality paper in the third step is carried out by a conventional method. That is, papermaking can be performed by a paper machine such as a fourdrinier paper machine or a twin wire machine, and paper having a small basis weight can be made by a circular net or short net yankee paper machine. Desk refiner prior to papermaking
Alternatively, the freeness is C.V. S. F. At 300-6
The beating is performed until the pulp is pulverized by the PA method, since the pulp obtained by pulping the line by the PA method can increase various strengths by beating as much as the freeness is high. It is convenient as a connecting pulp. When making paper, depending on your preference, a sizing agent,
Wet paper strength enhancer and other auxiliaries are added and the original concentration is 0.1 ~
At 0.8%, preferably 0.3-0.5%, the wire part of the paper machine is fed. The raw material supplied is formed into a wet paper with a wire part, sent to a press part to squeeze water, and then sent to a dry part to be dried and finished to a high quality paper.

[0011]

According to the present invention, bagasse pulp is used as a main raw material,
The use of non-wood pulp alone enables the production of high-quality bagasse paper without using wood pulp as a connecting pulp. That is, conventional bagasse pulp has been considered to be unusable as a raw material for paper because of its low strength, but by cutting the millet of the raw material plants diagonally and in parallel, a long lined is taken out, and this is subjected to alkaline cooking, preferably. Uses PA digestion to obtain strong pulp with various strengths, including the tearing height, which was previously considered to be low.By using this as pulp, it is possible to use high-quality bagasse high-quality paper without using any wood pulp. It has become possible to manufacture.

[0012]

Next, the present invention will be described more specifically with reference to examples, but the present invention is not limited to these examples.

[0013]

Embodiment 1

A sugar millet chip having a thickness of 20 mm and a length of 40 mm was prepared with a chipper equipped with a motor in which 3,000 kg of sugar cane stem was fixed to a rotating plate with two blades fixed at an angle of 30 °. Sugar millet chips with a screw press for solid content 4
It was disrupted and desalted to 5%. Kaneju obtained by destruction and desiccation
Is concentrated by the usual method, and the best squeezed brown sugar 230k
g was obtained. The sugar cane chips after destruction and desiccation are washed with a countercurrent washing machine to remove residual sugar, to obtain a sugar solution having a concentration of 5%, and to add nutrients.
The baker's yeast was cultivated while introducing high-concentration oxygen in which air was concentrated to 90% by a pressure-swing method.
2 kg was obtained. After the residual sugar was washed out, bagasse was squeezed again with a screw press, and then separated and removed with a dry-type 10-mesh vibrating sieve equipped with a motor. 210 kg of the obtained line was obtained in terms of absolute dry weight.

The sodium salt-based PA method (liquid ratio 1.8 L / kg, active alkali: Na 2 O 1
8%, causticization rate 85%, hydrogen peroxide: 3 as H2 O2
%, DTPA as a chelating agent 0.3%, ethyl anthraquinone as anthraquinones 0.1%, NMP (normal methylpyrrolidone) as a polar organic solvent arbitrarily mixed with water 0.1%, magnesium compound Magnesium oxide at 0.2% at 125 ° C for 2 hours)
Was subjected to gas phase digestion. The bleached pulp obtained by the gas phase digestion by the PA method was subjected to two-stage bleaching. That is, the first stage is treated with alkaline hydrogen peroxide, the second stage is treated with chlorine dioxide, and the whiteness is 83% and the freeness is C.I. S. F. 71
Unbleached millet pulp with 5cc, tear length 5.8km, specific burst strength 3.4, specific tear strength 106 vs. lined 50%
In a yield of

Fine paper is made of pulp (whiteness 81.8%, freeness CSF 405c) by bagasse AP method.
c, breaking length 2.8 km, specific burst strength 2.3, specific tear strength 45), 70%, and bleached PA method pulp of 30%, and 0.2% of alkyl ketene dimer. The paper was made by a conventional method using a fourdrinier paper machine for testing, with a raw material concentration of 0.3%, and a high quality printing paper (whiteness: 82.8%, tear length: 4.8 km, specific burst strength: 3.0) , Specific tear strength 8
7) was obtained.

[0017]

EXAMPLE 2 The sugar cane stem was used to obtain PA obtained in Example 1.
Pulp obtained by digesting abaca waste by the PA method under the same conditions as in Example 1 (break length 9.2 k)
m, specific burst strength 4.5, specific tear strength 189) 5%,
Was blended with 85% of the conventional bleached AP of bagasse, and the freeness C.I. S. F. The mixture was beaten to 445 cc, and a neutral sizing agent was added thereto. Using a fourdrinier machine for testing, a writing paper having a rice basis weight of 55 g was obtained by a conventional method. The writing paper had a breaking length of 3.8 km, a specific burst strength of 2.9 and a specific tear strength of 85.

[0018]

Example 3 Sweet sorghum stem was 2,000k
Then, a chip having a thickness of 15 mm and a length of 30 mm was prepared using a motor-attached chipper having two blades fixed to a rotating plate at an angle of 30 °. Sweet sorghum chips were disrupted and desalted to 43% solids with a screw press. The sugar solution obtained by disruptive desalting is used as a bioreactor with an invertase immobilized thereon.
And converted into invert sugar, and concentrated by a conventional method to obtain 151 kg of high-quality, most squeezed invert sugar with high nutritional value. After destruction and desiccation, the residual sugar is washed out with a countercurrent washer to recover a 4.5% concentration sugar solution, and nutrients are added, and high-concentration oxygen, which is concentrated to 90% by a pressure-swing method, is introduced to the food. 38 kg of yeast was obtained. After the residual sugar was washed out, bagasse was squeezed again with a screw press, and then the piss and the line were separated and removed with a 10-mesh vibrating sieve equipped with a motor. 150 kg was obtained in terms of absolute dry weight. The line obtained by desugaring and depissing is a potassium-based PA digestion solution (liquid ratio 1.8 L /
kg, active alkali: 18% as Na2 O, causticization rate 85%, hydrogen peroxide: 3% as H2 O2, DTPA 0.3%, anthraquinone 0.1%, NMP 0.1
%, 0.2% of magnesium oxide) at 125 ° C. for 2 hours. By the PA method, whiteness was 52%, kappa number was 4, and freeness was C.I. S. F. 710
An unbleached PA pulp of sweet sorghum having a cc of 6.7 km, a breaking length of 6.7 km, a specific burst strength of 4.0 and a specific tear strength of 120 was obtained at a lined rate of 52%. Example 1 of the pulp
The bleached pulp of sweet sorghum was bleached in two stages under the same conditions as the unbleached pulp of sugar cane. For the paper making of high quality paper, 80% bleached pulp of the same lot of bagasse used in Example 2 by the AP method and 20% of the bleached PA method pulp of the lined were blended, and 0.2% of alkyl ketene dimer was added. The paper was made by a conventional method using a fourdrinier paper machine for testing at a raw material concentration of 0.3%, and a high quality printing paper (whiteness: 82.3%, breaking length: 4.
0 km, a specific burst strength of 3.1 and a specific tear strength of 83).

Claims (4)

[Claims] 1. A method of cutting a stem of sugarcane or millet such as swee and sorghum diagonally and in parallel, and extracting a millet line (thick skin) as a pulp raw material in a state of long fibers. The second step is to treat the lined with an alkaline cooking chemical and to obtain chemical pulp with high tear strength and various strengths as a pulp for connection. Bagasse (sugar millet pulp) pulp is used as the main raw material. ,
The third step is to mix the milled pulp lined chemical pulp obtained in the second step as a connecting pulp to form a paper and comprises a combination of the first step, the second step and the third step. How to make quality bagasse paper without using any wood pulp. 2. In the second step, an alkaline cooking liquor used for digesting millet is prepared by a PA method (a chelating agent, anthraquinones, magnesium compound, oxygen compound as an auxiliary cooking aid in an alkaline solution of hydrogen peroxide). And a liquid containing at least one of polar organic solvents mixed with water at an arbitrary ratio is referred to as a cooking chemical liquid).
The method of claim 1 wherein the pulp of the process is blended as a tethered pulp in a third step. 3. In the third step, in addition to chemical pulp treated with alkaline alkaline cooking liquor, waste such as jute, abaca, banana fiber and other hemp is used as a binder pulp to be blended with the main bagasse pulp. 3. The method according to claim 1, wherein the paper is made using a chemical pulp. 4. Bagasse pulp, which is a main raw material of high quality paper, is 5
The process according to claim 1, 2 or 3, wherein the blending ratio of the connecting pulp is 0 to 95%, preferably 70 to 90% and 5 to 50%, preferably 10 to 30%.