KR101156665B1 - Rice hull fibers and high bulky rice hull fibers paper using rice hull fibers - Google Patents

Abstract

The present invention relates to the chaff fiber and high-bulk chaff fiber paper making using the same, the paper of the present invention by using the chaff fiber, the pores of the paper products produced according to the unique shape of the jagged fiber of the chaff is developed and relatively As it forms a thick and bulky structure, it not only has an excellent bulk improvement effect compared to the wood powder used for bulk enhancement, but also has high utilization due to its high physicochemical properties similar to wood fiber. By producing high bulk paper products, it improves paper properties such as stiffness and drying speed in the production process, reducing drying energy, and reducing waste of production costs and raw materials as an alternative resource of wood fiber, which is scarce worldwide. It will greatly contribute to the recycling of resources and the development of the paper industry.

Description

Rice hull fibers and high bulky rice hull fibers paper using rice hull fibers

The present invention relates to rice hull fiber and paper of high bulk using the same.

90-95% of the fiber stock, which is the raw material for paper, is derived from coniferous or hardwood timber, but is faced with structural supply and demand imbalance due to environmental concerns and regulations and the lack of available wood resources worldwide.

As the actual consumption of paper increased, the supply of wood fibers used steadily increased, increasing by 4% every year from 1999 to 2003.However, the production of non-wood fiber resources used as substitute fibers for wood resources was increased during the same period. Increased by more than%. It is expected that the use of non-wood resources to replace timber resources, which will be unstable and insufficient in supply and demand, will become larger and more important.

In order to replace wood fiber, many researches have been made on the pulping of various non-wood resources, fiber characteristics, and utilization methods. Non-wood resources can be largely divided into rice straw, agricultural by-products such as corn stalks, and industrial farming resources such as flax, sheep, and bamboo. In fact, various kinds of non-wood resources have different constituents and fiber characteristics according to their respective resources.

Therefore, in the application of non-wood fiber resources, it is necessary to select resources according to the end application and to develop and apply pulping and processing methods for each characteristic so that the utilization of commercially valuable resources can be brought.

On the other hand, the thickness of the paper is a structural characteristic that greatly affects the bulk, stiffness and opacity of the paper product. Increasing the paper thickness makes the paper bulk, which facilitates the drying of the paper during the paper making process, which can reduce the drying energy and can greatly improve the rigidity and opacity of the paper. In particular, bulk and stiffness are very important quality factors in various paper products including packaging paper. To improve these quality characteristics, many technological developments have been made to increase the thickness of paper, which directly affects the bulk and stiffness of paper. come.

In practice, the most widely used method to increase the thickness of the paper is to increase the basis weight of the paper. However, if the thickness of paper is increased through the increase of basis weight, not only the raw material of the product is used but also more dry energy is consumed during the process, the burden of energy cost and greenhouse gas increase and the weight of the actual packaging paper are increased. There are drawbacks that can lead to an increase in cost.

Therefore, in order to improve the thickness of the tributary product, Korean Patent No. 10-0954846 proposes a technique for improving the bulk of cardboard manufactured by using inorganic perlite as a filler in a paperboard manufacturing process. Similarly, Korean Patent Registration No. 10-898383 introduces a technique for improving the bulk of a product by adding paper flour to an intermediate layer of cardboard.

However, these methods improve the bulk of the product by using mineral or wood powder different from the actual wood fiber, and the disadvantages that may adversely affect the non-bulk properties, ie, optical and chemical quality properties, are mostly recycled. There is a disadvantage that the quality can be reduced when recycling the paper products.

On the other hand, there have been no cases of developing the related technology and evaluating the utilization of wood fiber as an alternative fiber and a functional fiber by extracting the silica component of the rice hull and separating the rice hull fiber to utilize the chaff fiber.

Accordingly, the present inventors have developed a technology for utilizing the chaff which is a representative agricultural by-product generated about 1 million tons every year in Korea to improve the bulk and rigidity of the paper. Silica in rice hull can cause many process and quality problems in the application of the raw material for rice husk, but in the present invention, the rice hull fiber is effectively prepared by separating the silica derived from the rice husk, and the technology of increasing the utilization of the rice hull fiber prepared Developed.

KR 10-0954846 B1, May 15, 2009 KR 10-898383 B1, May 12, 2009

Accordingly, the present inventors found that chaff fibers generated at the same time as the separation of porous silica from chaff, which is a representative agricultural by-product, with high purity and high efficiency, and found that it is possible to manufacture structurally thick paper than paper using conventional wood fibers. The present invention was completed.

An object of the present invention is to provide a high bulk rice hull fiber paper and a method of manufacturing the same using chaff fibers containing rice hull fibers that can promote the recycling of waste resources and the development of the paper industry as an alternative resource of wood fibers.

Hereinafter, a manufacturing method of the present invention will be described in detail with reference to the accompanying drawings. The drawings introduced below are provided as examples and may be exaggerated in order to sufficiently convey the spirit of the present invention to those skilled in the art.

Hereinafter, the technical and scientific terms used herein will be understood by those skilled in the art without departing from the scope of the present invention. Descriptions of known functions and configurations that may be unnecessarily blurred are omitted.

The present invention provides a high bulk rice hull fiber paper and a method for producing the same using chaff fibers of high purity obtained from the extraction residue of natural silica concentrated in the husk husk.

The high bulk rice hull fiber paper of the present invention is characterized in that the length-weighted average fiber length is 0.4 to 0.6 mm and includes chaff fibers which are simultaneously separated from the chaff having a cylindrical fiber shape and a serrated fiber shape in the long fiber.

The chaff fiber of the present invention is subjected to alkali cooking of washed rice husk or rice straw to separate the cooking liquor, and the cooking residue, and to separate and separate the fiber powder from the separated cooking residue and the separated cooking liquor. , Characterized in that obtained by classification of the separated fiber powder.

Chaff fiber of the present invention is characterized by having a chemical composition of carbon 65 to 75%, oxygen 25 to 30%, silicon 0.1 to 0.5% calcium 0.3 to 1.0%.

Paper making of the present invention is characterized by having a physical property of the thickness of 80 to 250 ㎛ and bulk 1.9 to 3.0 cm 3 / g.

Hereinafter, the present invention will be described in detail.

The present invention provides a high-bulk, characterized in that it comprises 1 to 50% by weight of rice hull fibers simultaneously separated from rice hulls having a length-weighted average fiber length of 0.4 to 0.6 mm and having a cylindrical fiber and a serrated fiber. Provides chaff fiber paper.

In the present invention, the chaff fibers separated from the chaff at the same time is subjected to alkali cooking of washed chaff or rice straw to separate the cooking liquor and the cooking residue, and from the separated cooking residue from the fiber powder and the separated cooking liquor. After silica precipitates and is separated, the separated fiber powder is classified and obtained.

In addition, the present invention may further comprise the step of surface treatment on chaff fibers obtained by the above method. In more detail, by performing ozone treatment under acidic conditions, after acetic acid treatment to prevent ozone decomposability in rice hull fiber, 150 to 200 g / m 3 ozone concentration for 30 to 90 minutes is applied to the tension according to the bulk improvement. In addition to reducing the strength, there is an advantage that can bring about an additional synergistic effect of the whiteness.

The content of the chaff fiber reacted during the ozone treatment is 10 to 50%, more preferably 20 to 40% of the content is appropriate, and treatment with acetic acid at pH 2.5 to 5.5, more preferably pH 3 to 4 Preferably, only in the above processing conditions can minimize the further degradation of carbohydrates in the rice hull fiber and exhibit the optimum effect.

The cooking process is to add a sodium hydroxide solution or ammonia solution per weight of rice husk or rice straw under a condition of pH 10 or more in a ratio of 1: 5 to 10 by weight to cook at a temperature of 100 to 200 ℃, preferably 120 to 170 ℃ It is characterized in that the cooking process for 30 to 140 minutes at a temperature of.

The present invention relates to a wood fiber having a cylindrical fiber shape and a serrated fiber shape in a longitudinal fiber of 0.4 to 0.6 mm in average length, which is morphologically similar to the pulp of wood fiber through the alkaline cooking process of rice hull or rice straw. It is possible to extract the natural fiber having a pulp form with high efficiency. See FIGS. 1 and 2.

More specifically, the alkaline cooking process is for removing the minerals present in the rice husk, chaff fibers are separated by dissolving rice hull silica which combines rice hull fibers and rice hull silica which reduces the utility of rice hull fibers under strong alkaline conditions. After separation, the dissolved silica can be precipitated and purified from the extract.

The alkaline cooking treatment may further include a quinone catalyst.

More specifically, a catalyst of 0.1 to 1.0% by weight of quinones, based on the weight of washed rice husk or rice straw, may be added to promote the decomposition of lignin and to reduce the generation of flakes, which are undissociated powder, to improve the yield of the fiber.

The quinones are one or more selected from anthraquinones, benzoquinones and naphthoquinones, preferably anthraquinones.

In the present invention, the chaff fiber is characterized in that the chemical composition of carbon 65 to 75%, oxygen 25 to 30%, silicon 0.1 to 0.5% calcium 0.3 to 1.0%, there is no inorganic material such as silica. It is done.

More specifically, when silica remains in the wood fiber replacement pulp, there is a problem of degrading its utility value due to contamination of the process. Therefore, chaff fiber of the present invention has an advantage that can be effectively separated from the silica in the rice husk to prepare chaff fiber.

Paper making according to the present invention may further comprise chaff fiber wood flour.

More specifically, as a result of investigating the change of physical properties of the wrapping paper prepared by uniformly mixing the mixed ratio of coniferous unbleached coniferous kraft pulp: chaff pulp under the conditions of 8: 2, 6: 4, 4: 6 and 2: 8, respectively. As the blend ratio of chaff fiber increased, the bulk of the paper was found to increase linearly, and compared to the coniferous fiber, it showed a thin fiber shape and particularly sawtooth-fiber fibers. See FIG. 3.

In the present invention, the paper is characterized in that it has a thickness of 80 to 250 ㎛, more preferably 165 to 180 ㎛ and bulk 1.5 to 3.5 cm 2 / g.

More specifically, the cardboard inlays produced by dissolving the corrugated cardboard used as the inlay of corrugated cardboard and white cardboard with high concentration pulp and then adding 6% chaff fibers in weight ratio, compared to the corrugated cardboard and wood-containing paper As the paper becomes thicker, it can be seen that the bulk is greatly improved. In addition, unlike the conventional wood flour, because it has a sawtooth-like fiber form it can be confirmed that it has an improved strength characteristics, chaff fiber has a relatively superior functional characteristics than wood flour.

The paper of the present invention is relatively thick in papermaking pores according to the peculiar shape of the chaff fiber by using chaff fibers, the thickness is relatively thick, compared to the conventional wood flour, as well as excellent bulk improvement effect of wood flour and other fiber types It has the effect of improving the strength and reducing the drying energy in the production process, and will greatly contribute to the recycling of waste resources and the development of the paper industry as an alternative resource of wood fiber.

1 shows that the actual chaff fibers are attached in an unseparated state when the outermost layer of the rice husk, which is concentrated on the chaff silica, is separated through alkali treatment.
Figure 2 shows a photograph of the morphology of the chaff fiber according to the present invention observed with an electron microscope,
Figure 3 shows a photograph of the surface of the paper made of rice hull fibers 40% of the present invention observed with an electron microscope.
(A: × 50 ratio, B: × 300 ratio)

The present invention will be described in more detail with reference to the following examples. However, the following examples are provided to aid understanding of the present invention, and the scope of the present invention is not limited by these examples in any sense.

Hereinafter, the technical and scientific terms used herein will be understood by those skilled in the art without departing from the scope of the present invention. Descriptions of known functions and configurations that may be unnecessarily blurred are omitted.

[Production Example 1]

Rice husks sold from rice bran were washed with distilled water and dried. The prepared rice husk sample was mixed with 20% NaOH in a liquid ratio of 5: 1 and subjected to cooking treatment at 170 ° C. The time to reach the final cooking temperature was adjusted to 30 minutes, and the cooking process was performed while maintaining the cooking temperature for 120 minutes. In the cooking process, 0.3% of anthraquinone catalyst was added to perform cooking. After the cooking process, the cooking liquor and the cooking residue were compressed and separated, and the remaining residue was sufficiently washed and classified into fiber powder and flakes by applying 40 mesh and 200 mesh to obtain rice hull fiber.

[Production Example 2]

Chaff fibers were prepared in the same manner as in Preparation Example 1, except that 20% NaOH was mixed at a liquid ratio of 5: 1 to the chaff sample prepared without the addition of the anthraquinone catalyst, followed by cooking treatment at 170 ° C.

[Examples 1 to 8]

A laboratory circular herbicide was used to obtain a plant weight of 80 g / m² based on TAPPI standard T205 om-88. At this time, by using a valley beater, the coniferous unbleached coniferous kraft pulp (UBKP), which is commercially available, was treated with 10 minutes of dissociation and 30 minutes of beating to prepare a standard wood fiber sample, and the chaff fibers of Preparation Examples 1 and 2 were prepared. Were mixed uniformly under the conditions of 8: 2, 6: 4, 4: 6, 2: 8 (conifer UBKP: rice husk pulp), respectively, to prepare a raw material as shown in Table 1 below. The mixed raw materials were mixed and weeded in the form of paper. The water-treated paper was squeezed out using a press machine and dried by applying a drum dryer to prepare a paper-making paper.

Example 9

After dissociating the corrugated cardboard (OCC: Old Corrugated Container) used as an inlay of corrugated cardboard and white cardboard with high concentration pulp, and then uniformly mixed with the chaff fiber of Preparation Example 1 by weight ratio of 6%, in the form of paper Plants were prepared by adding 100% corrugated cardboard (control 1) and wood flour instead of the chaff fibers (control 2) as a control. The water-treated paper was squeezed out using a press machine and dried by applying a drum dryer to prepare a paper-making paper.

The wood powder was used to dry the sawdust 100g, so that the moisture content is less than 10% by weight, and wood flour prepared by grinding the dried sawdust with a grinder.

[Test Example 1]

Morphological characteristics of the chaff fibers prepared by the method of Preparation Example 1 and Preparation Example 2 were evaluated by a fiber length analyzer and the results are shown in Table 2 below.

Morfi Analyzer (Techpop, France) was applied to evaluate the morphological characteristics of rice hull fiber. The fiber length, change of fiber distribution, fine content, and coarsness of each rice hull fiber were analyzed, and the distribution of rice hull fiber was prepared using field emission scanning electron microscope (JEOL / JSM-7000F). Observed using. Observation conditions were resolution 1.2 nm (30 kV), observation ratio x100 to x500,000, acceleration voltage 0.5 to 30 kV, and electron gun type In-lens type Shottky Field Emission Electron.

As can be seen in Table 2, the fiber length had a slightly shorter fiber length than 0.5 hardwood fibers and other non-wood fibers, kenaf, reeds, silver grass, etc., and the fiber thickness was about 0.5 mm.

In addition, it was confirmed through Figure 1 that the chaff fiber is attached in the unseparated state when the chaff outermost layer in which the chaff silica is concentrated through alkali treatment, the chaff fiber is actually present in the present invention Through the sea treatment has a sawtooth-like fiber form that can be seen in Figure 2, unlike the existing wood flour was confirmed that the unique characteristics of chaff fiber.

The protruded serrated components were analyzed by SEM-EDS, and are shown in Table 3 below.

As can be seen from the chemical composition of the projections of Table 3, it was confirmed that the actual minerals such as silica is virtually absent, which is confirmed that the chaff fiber of the present invention has excellent utilization value as a wood fiber replacement pulp It is also.

[Test Example 2]

The change in physical properties of the wrapping paper according to the rice hull fiber blending ratio using the sheet of paper of Examples 1 to 8 was investigated.

The physical property change was measured by the following method.

The prepared paper was humidified at a temperature of 23 ± 1 ℃ and a relative humidity of 50 ± 2% according to TAPPI standard T402 om-83, and then made a specimen for strength measurement according to TAPPI Standard T220 om-88. -88) (T403 om-85), rupture strength (T403 om-97), and the like were measured, and the brightness (T 452 om-98) and Opacity (TAPPI T 452 om-96) were measured.

It can be seen that the bulk of the paper increases linearly as the blend ratio of chaff fiber increases. In addition, in order to determine the characteristics of the chaff fiber binding in the paper, the surface of the paper made of chaff fiber 40% (Example 2) was observed by applying an electron microscope.

As a result, as shown in Figure 3, it can be seen that there are fibers having a finer form than the coniferous fibers and in particular having a sawtooth-shaped form.

[Test Example 3]

The change in the properties of the sheet produced in Example 9 was investigated.

As can be seen from the results of Table 5, when the chaff fiber 6% is added, it can be confirmed that the bulk of the paper is significantly improved as the thickness of the paper than the conventional cardboard and wood flour-containing paper.

In addition, in the case of chaff fiber, although the thickness improvement effect is greater than that of wood flour, unlike the wood flour, it has a sawtooth-like fiber shape, so the strength characteristics are found to be somewhat higher. As a result, it has confirmed that it has excellent functional characteristics.

In addition, this thickness improvement effect is expected to reduce the drying energy in the actual production process.

[Test Example 4]

The bulk improvement due to the addition of rice hull fiber brings about a decrease in strength. To compensate for the decrease in strength, the surface treatment of rice hull fiber was performed.

In order to change the surface properties of the rice hull fiber and improve its binding to the OCC short fiber (corrugated cardboard), 26% chaff fiber (74% solution) was adjusted to pH 3 with acetic acid (pH 2.7) and ozone concentration 170 Ozone treatment was performed at g / m 3. 60% of the rice hulls treated with ozone evenly and untreated (unozone) rice hulls were mixed with 10% of corrugated cardboard, and each pulp paper was used to make 85 g / m² basis weight. Evaluated.

As can be seen in Table 6, it was confirmed that the bulk of about 15% of the bulk of the paper added 10% chaff fiber compared to the 100% corrugated cardboard. In the case of tensile strength, the reduction was about 19%. In this case, when the chaff fiber was ozone-treated and added, the bulk improvement effect was reduced to about 11%, but the decrease in tensile strength was about 12%. I could confirm that there is. It was confirmed that the change of surface characteristics of rice hull fiber by ozone treatment resulted in additional synergistic effect of whiteness.

Claims (9)

A high bulk rice hull fiber paper, characterized in that it comprises 1 to 50% by weight of rice hull fibers having a cylindrical fiber shape and a serrated fiber shape in a long fiber having a length weight average fiber length of 0.4 to 0.6 mm. The method of claim 1,
The chaff fiber is subjected to an alkaline cooking process of washed rice husk or rice straw to separate the cooking liquor and the cooking residue, and to precipitate and separate the silica from the separated cooking liquor and the fibrous powder from the separated cooking liquor. High bulk chaff fiber paper, characterized in that obtained by classifying the separated fiber powder. The method of claim 2,
The chaff fiber is a high bulk rice hull fiber paper, characterized in that it further comprises ozone treatment under acid conditions. The method of claim 3, wherein
The rice hull fiber is a high bulk rice hull fiber paper, characterized in that after treatment with acetic acid concentration of 150 to 200 g / ㎥. The method of claim 2,
The rice hull fiber is 65-75% carbon, 25-30% oxygen, 0.1-0.5% silicon 0.3-1.0% of the chemical composition of the high bulk rice hull fiber paper. The method of claim 2,
The cooking process is a high bulk rice hull fiber paper, characterized in that the cooking process at a temperature of 100 to 200 ℃ by adding sodium hydroxide solution or ammonia solution per weight of rice husk or rice straw in a ratio of 1: 5 to 10 under a condition of pH 10 or more. . The method according to claim 6,
The cooking process is a high bulk rice hull fiber paper, characterized in that the cooking process for 30 to 140 minutes at a temperature of 120 to 170 ℃. The method of claim 1,
The paper is a high bulk chaff fiber paper, characterized in that it further comprises wood powder. The method according to any one of claims 1 to 8,
The paper is a high bulk chaff fiber paper, characterized in that having a thickness of 80 to 250 ㎛ and bulk of 1.5 to 3.5 cm 3 / g.

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