KR101010978B1 - Method of Manufacturing an opaque paper using Genus Typha L. - Google Patents

Abstract

The present invention relates to a method of manufacturing an opaque paper using parts, wherein the method of manufacturing the paper comprises the steps of preparing a bleach pulp from the parts (Genus Typha L.), and a step of manufacturing paper from the bleached pulp. Include. The manufacturing method of the paper according to the present invention can provide a low basis weight paper having a basis weight of 120 g / m ² or less while using an inorganic filler or using a very small amount, and exhibits high opacity, smoothness and printability, and does not use an inorganic filler. By using a very small amount, there is an advantage that the decrease in mechanical strength due to the addition of the inorganic filler does not occur significantly.

Boulders, paper, opacity, smoothness, tensile strength, pulp pulp, wood pulp, pollen

Description

Method of manufacturing an opaque paper using Genus Typha L.

The present invention relates to a method for producing an opaque paper using parts, and more particularly, to a method for producing a low basis weight paper showing high opacity, smoothness, and printability without using an inorganic filler, and having excellent mechanical strength. It is about.

Genus Typha L. is a perennial herb belonging to the Typhaceae family with 9 to 18 species worldwide. It is known that three kinds of native oysters (Typha orientalis), babies (Typha angustata), and typha latifolia are native (Choi, 2000; Chung, 1957; Im, 1998; Kim and Choi). , 2001; Lee, 1996; Mori, 1922; Nakai, 1911, 1951). Large parts and zombies are easily distinguished by the width of the leaves, but these two types have stamens and pistils, but the baby parts are characterized by a narrow leaf and the upper part of the pistil and the stamens separated by 4 to 6 cm. In Korea, the most common findings across the country are baby babies. In America, broad-leaved cattail (Typha latifolia L.) or common cattail is called broad-leaved cattail (Typha angustatifolia L.). In the latter case, the surgical and pistil parts are separated like those of native babies in Korea, but their morphological characteristics are somewhat different.

The wealthy people dry in winter and hibernate with underground scenes and have a habit of staying young. The pollen of the buds is called phoenix and is used as a herbal medicine. Young shoots, stems, roots, etc. are also used for food. In addition, it is known that it plays a big role in the purification of pollutants in wetlands, the value of its use is increasing gradually, and many people are trying to use aquatic plants for wastewater treatment or water purification in Korea.

It is a very meaningful attempt to use wealth as an environmental clean-up plant and further grow it as an edible or resource plant. Departments are attracting attention as future bioenergy crops because of the high level of development of the ground and roots, which produce large amounts of biomass. Whereas straw or reed produce 8.5-11.2 tonnes / ha and 6.4-12.5 tonnes / ha dry weight biomass, the departments produce 10.6-14.7 tonnes / ha biomass and 14.5-22.7 tonnes fertilizer. It has been reported that it produces / hectares of biomass (European, et al., ARPC Report, 2007, p95).

Currently, wood is mainly used as a raw material for paper manufacturing processes. Wood is composed mainly of cellulose, hemicellulose, and lignin, and pulp is produced through the pulping and bleaching processes. Pulping and bleaching is the process of removing lignin from wood.

The process for producing bleached pulp from wood is as follows. In the process of processing a wood raw material in the state which is easy to pulp, there are operations, such as cutting, peeling, and sorting, and this is performed suitably according to the kind of raw material. The process of obtaining fibers from the raw material after the preparation process is called a pulping process and is the most important process in pulp production.

Treatment of the pulp feedstock with ligignin chemicals dissolves lignin and dissociates it into fibrous form. Pulp prepared in this way is called chemical pulp. In the production of chemical pulp, not only the lignin in the intercellular layer of the raw material but also most of the lignin in the cell membrane are removed, many hemicelluloses are dissolved, and some cellulose is also degraded. Chemical pulp production methods include sulfurous acid method, soda method, sulfate method and kraft method. Among them, kraft pulping is usually used. The selection process is a process of washing and screening fibers obtained from the raw material after the pulping process to remove parts and contaminants that are not completely pulped, and then bleaching as necessary. As such, the process for producing pulp from wood requires a high temperature and high pressure process, and a large amount of chemicals is used.

For wood pulp, it is common to include inorganic fillers in paper in order to improve optical properties. Paper having a high opacity is particularly preferable for writing paper and high-quality printing paper. In this regard, it is necessary to properly retain the inorganic filler in the fiber in order for the inorganic filler to remain with the fiber in the paper making process. Commercially, this is generally accomplished by agglomerating fillers and fibers using cationic starch or similar flocculant. However, even with such chemicals, inorganic filler losses can be significant, especially in low basis weight products or high speed papermaking processes. Low retention of inorganic fillers can lead to blockage of the papermaking felt, contamination of the white water system and an increase in raw material costs. As such inorganic fillers, calcium carbonate, titanium dioxide, talc, clay and other suitable inorganic salts have been incorporated into the fibers, but too high a quantity reduces the mechanical strength of the paper and makes it difficult to use as recycled paper. The problem remains that the inorganic filler is not sufficiently filled.

Inorganic fillers are the most used in the raw materials of paper except pulp, and generally 5 to 30% by weight is contained in the paper. As a mineral powder added to pulp when papermaking, clay, kaolin, talc, calcium carbonate and the like are used to make the paper white and opaque, and to improve the printability, dimensional stability and handwriting of the paper. However, such inorganic fillers have the disadvantage of lowering the strength of the paper and facilitating contamination by friction during the production of low basis weight paper or high speed paper.

Basis weight is a unit that means mass per unit area, and low basis weight paper of 100 g / m ² or less is used in various industrial fields such as newspaper and OA paper. In the case of low basis weight paper, a relatively large amount of inorganic filler should be used for the opacity, so that the decrease of the intellect is inevitable.

Therefore, there is a growing need for paper manufacturing methods that can increase the opacity without using inorganic fillers.

SUMMARY OF THE INVENTION In order to solve the problems of the prior art, an object of the present invention is to provide a method for producing a low basis weight paper which is excellent in opacity, smoothness and printability without using or using a small amount of an inorganic filler.

Another object of the present invention is to provide a method for producing a low basis weight paper having excellent mechanical strength.

Still another object of the present invention is to provide a method of producing paper of high quality at low cost.

The present invention provides a bag of bleached pulp bleached with an ISO whiteness of at least 70% from the bags to achieve the above object, and a step of preparing paper from the bleached pulp of paper. It provides a manufacturing method. The present invention also provides a low basis weight paper which does not contain an inorganic filler or which is contained in an amount of 10% by weight or less and which is excellent in opacity and mechanical strength.

The method for producing an opaque low basis weight paper comprising a bleached pulp according to the present invention can provide a low basis weight paper having a basis weight (mass per unit area) of 120 g / m ² or less by using an inorganic filler or a very small amount. In addition, the use of the inorganic filler or the use of a very small amount has the advantage that the mechanical strength decrease due to the addition of the inorganic filler does not occur significantly.

Increased mechanical strength by using the bleached pulp can be expected to reduce production costs by inducing a reduction in basis weight of paper.

In addition, the paper made of wood pulp exhibits a higher opacity or higher than that of the inorganic filler and has excellent smoothness, and because there are few minerals in the paper, the bays on the paper have the advantage of less scratches.

In addition, the bleached pulp can increase the smoothness of the paper and improve the printability of the paper. Particularly in the case of low basis weight paper, the retention of inorganic filler is very difficult, but the use of the bleached pulp makes the bleach pulp itself not only an opaque inorganic filler but also an excellent retention of the inorganic filler. Cost savings can also be expected.

As the depletion of wood resources around the world becomes severe, the task of the industry is to produce paper stock pulp while protecting forests and the environment. In order to solve this problem, a technique for producing paper pulp from non-woody plant fibers has been attracting attention.

Non-woody plants that can be used as a raw material for papermaking include bark, flax, hemp, cotton, rice straw and bagasse. In general, non-wood plants contain high levels of pectin, hemicellulose, and minerals, low lignin, and chemical, semi-chemical and mechanochemical methods are used when pulping and unbleached under very mild conditions compared to wood. Or bleached pulp can be obtained.

Non-woody pulp has different properties depending on its fiber type, chemical composition, and the type and amount of non-fibrous cells. Therefore, the paper made by the non-woody pulp alone or by proper blending with wood pulp can easily control the mechanical strength, durability, electrical characteristics, gloss, dimensional stability and printing performance, and can be used for various purposes. Therefore, the use range is also wide.

In the present invention, parts are used as raw materials for manufacturing paper. According to one embodiment of the present invention, a step of preparing a bleach pulp from the parts, and a paper from the bleach pulp. The paper manufacturing method exhibits significantly higher opacity, mechanical strength, smoothness, and printability than paper made of wood pulp containing 5-30% by weight of conventional inorganic fillers with significantly less or no inorganic filler. Opaque low basis weight paper can be provided.

Hereinafter, the paper manufacturing method of the present invention will be described in detail step by step.

1. Pulping of the Wealth

The wealth is a perennial herb belonging to the Typhaceae, which is distributed from 9 to 18 species all over the world, and selected from among the wealth of Typha orientalis, Typha angustata, and Typha latifolia. That's it. However, the present invention is not limited thereto and includes all parts in which minimal fibers are present.

 The leaves and stems of the boulders contain significant amounts of good cellulose fibers that can be used to make special paper. They grow much faster than trees and can compete with wood pulp as a raw material that can be harvested from most of the temperate regions.

 After harvesting pollen, the roots are used in the ethanol manufacturing process using carbohydrates, and the leaves and stems are used as raw materials for pulping. Departments also play a major role in the purification of pollutants in wetlands, so when mass production of pulp as a raw material of pulp, pulp can produce high quality pulp at a lower cost than wood pulp, and it can be expected to have side effects such as water purification.

 At this time, pulp can be produced using the same process as wood pulping and bleaching process, and pulping is possible using a milder process. Before pulping, the mixed hardwood chips were 62.0 wt% and 24.1 wt% dry weight, respectively, and the holocellulose and lignin of the mixed leaves and stems were 63.2 wt. Weight percent and 22.3 weight percent. However, in the case of the parts before the pulp process, the ash content is slightly higher, reaching 3.8% by weight of dry weight, compared to 1.72% by weight of hardwood. However, the ash content of the bleached fiber is lowered to less than 1% by weight relative to the dry weight, there is no problem in the use of the fiber.

 The boulders used as bleaching pulp are very thin. The thinner the fibers, the greater the surface area of the fibers per unit weight, and the surface of the paper made of these fibers is very smooth and suitable for printing paper. In addition, the surface area is very high, it can be said to be very useful for filters.

The bleached pulp prepared in the present invention exhibits an ISO whiteness of 70% or more, preferably an ISO whiteness of 80% or more. The bleached pulp has an average of 0.02 to 0.08 ug / m fiber coarseness. Fiber roughness refers to the total dry weight of the fiber required to be 1 m when the fibers are arranged next to each other in the longitudinal direction, and the fiber roughness in the above range can be classified as a very thin pulp. have.

The bleached pulp contains 3% by weight or less, preferably 1.5% by weight or less, more preferably 0.01 to 1.5% by weight of Klason lignin. The bundle fibers of the bleached pulp are mixed with a very small amount of fibers in length and width, but the average fiber length is 0.4 to 0.9 mm in length weight, and the average fiber width is 8 to 15 um. When the bleached pulp has the whiteness, fiber roughness, Klason lignin, average fiber length and average fiber width described above, it is possible to produce paper having excellent opacity and smoothness.

The leaves and stems of Typha orientalis, Typha angustata, Typha latifolia, etc. can all be used as raw materials for pulp. In particular cases by controlling the amount of leaves and stems, it is possible to control the mechanical strength properties and opacity of the bleached pulp. If the stem part is used a lot, the strength is increased, but the opacity is less and the dehydration is slow. On the other hand, when the leaf part is mainly used, the opacity is increased and the dehydration is faster.

When pulping the parts by kraft method, NaOH and Na ₂ S chemicals (active alkali) are used, and active alkali (NaOH + Na ₂ S) is used in an amount of 5 to 25 parts by weight based on 100 parts by weight of the total weight of the parts. and the content of (Na ₂ S / (NaOH + Na ₂ S) x100%) of Na ₂ S of the drug is preferably in the range from 5 to 30% by weight. The bulges together with the drug completes the pulping reaction by reacting more effectively at 140 to 200 degrees Celsius for 2 to 6 hours at 160 to 190 degrees Celsius. The pulped raw material is thoroughly washed and passed on to the next bleaching process. At this time, the pulping process of the parts is not limited to the kraft method simply, and includes all general deligignization pulping methods such as soda method, sulfate method, sulfurous acid method, and delignination method using oxygen.

Bleaching may be done by using chlorine, or through ECF (Element chlorine free) bleaching process using bleaching with ozone, chlorine dioxide, hydrogen peroxide, peracetic acid, or TCF (using ozone, hydrogen peroxide, peracetic acid). Total Chlorine Free) Bleached pulp is produced by the bleaching process.

2. Manufacture of Paper Using Bleached Pulp

The step of making paper from the bleached pulp is generally similar to the step of making paper, but produces paper with high opacity with significantly less or no inorganic filler. In order to increase the opacity, the use of inorganic filler generally decreases the mechanical strength. However, when the bleached pulp is used, the high opacity and high strength low basis weight paper is used because the inorganic filler is not used or significantly less. It can manufacture.

The step of preparing paper from the bleached pulp of the present invention comprises the steps of beating the bleached pulp fibers; Sorting and selecting the beaten fibers; And papermaking and processing of the selected paper.

In general, "paper" refers to a cellulose fiber in the form of a sheet so that it can be used for printing, writing, packaging, etc., and manufacturing paper suitable for the purpose by various treatments is called "paper". The paper making process, or papermaking process, varies slightly depending on the purpose of the paper, which is the final product.

1) Confession process

If the pulp produced in the pulp mill is made of paper without any processing, the paper is difficult to be used for general purposes, such as weak strength and excessive surface roughness. This is because the fibers of natural pulp are rigid and have a low surface area, which causes the fibers to hardly bond.

Therefore, the fibers must be mechanically treated in water to make them suitable for papermaking. This process is called beating. The confession makes the fibers flexible and increases the bonds between the fibers, so the paper becomes denser as the altitude rises.

2) Screening and selection process

Before the pulp raw material obtained in the beating step is sent to a paper machine, it is a step of removing the contaminants mixed in the pulp raw material to make the properties of the paper produced constant.

3) Grassland process

It is a process of forming a paper from a pulp raw material mixed with pulp, a sizing agent, and various additives on a wire, and then crimping, dehydrating and drying to make paper. The sizing process is a process of imparting resistance to penetration of ink or water on paper, and the chemicals used are called sizing agents. According to the method of forming the paper on the wire, the paper machine is divided into a long mesh, a circular mesh, and a twin mesh.

4) Machining

Processing is a process of performing various processing such as coating and laminating using manufactured paper as a base.

The papermaking process with significantly less or no addition of inorganic fillers provides a method for producing low basis weight paper with high opacity. In low basis weight papers having a basis weight of 120 g / m ² or less, the use of inorganic fillers to increase the opacity in paper manufacturing generally has the disadvantage of lowering mechanical strength. When using the bleached pulp, there is an advantage that a low basis weight paper having high opacity and excellent strength is not used because an inorganic filler is not used.

In addition, producing paper from the bleached pulp may further comprise mixing the pulp bleached pulp with a second pulp of wood pulp, or other non-woody pulp, depending on the desired paper properties. . The bleached pulp is used in an amount of 10 to 90% by weight and the second pulp may be used in an amount of 90 to 10% by weight, preferably in an amount of 50 to 90% by weight and the second pulp is 10 To 50% by weight. By mixing the bleached pulp and the second pulp in the above range it is possible to produce a paper having the desired characteristics by adding the properties of the second pulp to the bleached pulp.

     The wood pulp may be a blended pulp made by mixing hardwood pulp and coniferous pulp at an appropriate ratio. The paper prepared by mixing the blended pulp and the bleached pulp can produce a paper having higher mechanical strength, such as tensile strength, and relatively good smoothness at the same opacity, compared to paper prepared by mixing the blended pulp and the inorganic filler. There is an advantage.

       Examples of the non-wood pulp may include pulp made from mulberry bast, flax, hemp, cotton, rice straw, bagasse, or red algae.

       It is also possible to include a very small amount of inorganic filler in the manufacture of paper from said bleach pulp. As the inorganic filler, a material selected from the group consisting of clay, kaolin, talc, calcium carbonate and mixtures thereof may be used. When using these inorganic fillers, the usage-amount can be used in the quantity of 10 weight% or less with respect to the total amount of a pulp and an inorganic filler, and it is preferable to use 1 to 9 weight%.

Hereinafter, the present invention will be described in detail by way of examples. However, the following examples are illustrative of the present invention, and the contents of the present invention are not limited by the following examples.

Example  1: Preparation of Boulded Bleached Pulp

The pulp bleached pulp was prepared by kraft pulping, and the pulp was mainly occupied by babies, and was used without distinguishing the leaves and stems of the buds. 12 parts by weight of active alkali (NaOH + Na ₂ S), 20% by weight of sulfide was used as a dry weight of the parts, and the solution containing the drug: the weight ratio of parts was 4: 1, and the cooking temperature was 150 degrees Celsius. After reaching the island, cooking was carried out for 2 hours. After the completion of the reaction, the raw materials were sufficiently washed, followed by chlorine dioxide bleaching in an acidic state of pH 3-4, and bleaching with hydrogen peroxide in an alkaline state of pH 11-13. After bleaching, the ISO whiteness was 84.5%. Reached. Table 1 shows the properties of the completed pulp. For comparison, the measurements for commercial bleached softwood pulp and commercial bleached softwood pulp are listed in Table 1.

The average fiber length, average fiber width, fiber roughness, and fines (area%) of Table 1 were measured by Morfi Analyzer (Techpop, France). ISO whiteness was measured according to ISO 2470-1977. In the following Table 1, the average fiber length was compared by length weights, not arithmetic average values. In the case of fines, it means the percentage of area produced by fibers less than 0.2 mm in length.

Average fiber length
(mm)
Length weighting Average fiber width
(um) Fiber roughness
(ug / m) Fine powder
(area%) ISO whiteness
(%) Commercial Bleached Conifer Pulp 1.994 26.7 0.185 2.3 86.4 Commercial Bleached Hardwood Pulp 0.657 20.4 0.129 9.86 85.8 Example 1
(Bleach bleached
pulp) 0.591 12.6 0.049 9.2 84.2

As shown in Table 1, the bleached pulp was found to have a smaller average fiber length and average fiber width than the softwood or hardwood pulp. In particular, it was found that the fiber roughness was significantly less. In other words, it can be seen that the bleached pulp is a fiber capable of producing paper of fine structure.

Example  2: manufacture of paper

As shown in Table 2 below, the bleached pulp of Example 1 was beaten so that the degree of freedom was 450CSF, and a paper having a basis weight of 60 g / m ² was prepared.

Example  3: manufacture of paper

As shown in Table 2 below, the bleached pulp of Example 1 was beaten so that the degree of freedom was 300CSF, and a paper having a basis weight of 60 g / m ² was prepared.

Comparative example  1: manufacture of paper

As shown in Table 2 below, after mixing the commercial bleached coniferous pulp used in Example 1 and the commercial bleached softwood pulp at a weight ratio of 50:50, the basis weight of 60 g of pulp subjected to beating so that the freeness reached 400 CSF / m ² paper was prepared.

Comparative example  2: manufacture of paper

As shown in Table 2 below, after mixing the commercial bleached coniferous pulp used in Example 1 and the commercial bleached softwood pulp at a weight ratio of 50:50, the calcined pulp was subjected to beating so that the free water reached 400 CSF. 10 wt% was added to produce a basis weight of 60 g / m ² of paper.

Comparative example  3: manufacture of paper

As shown in Table 2 below, after mixing the commercial bleached coniferous pulp used in Example 1 and the commercial bleached softwood pulp at a weight ratio of 50:50, the calcined pulp was subjected to beating so that the free water reached 400 CSF. 20 wt% was added to produce a basis weight of 60 g / m ² of paper.

Experimental Example

Examples 2, 3, and the paper prepared according to Comparative Examples 1-3, the basis weight, density, thermal shear, smoothness, cut resistance, whiteness, opacity and ash were measured and listed in Table 2 below.

In Table 2, the basis weight refers to the weight of paper in an area of 1 m ² , and the density refers to the weight of paper at 1 cm ³ , and in general, the thickness of the paper is measured and divided by the basis weight. Thermal shear refers to the tensile strength measured under the assumption of the same basis weight for papers with different basis weights, and the bekk smoothness refers to the smoothness measured on a smoothness measuring instrument called bekk. The higher the number, the smoother it is. Internal theft represents the number of times the paper is destroyed when repeated folding and unfolding of the paper, and ash represents the weight of ash remaining after burning the paper for more than 1 hour at 400 degrees Celsius. Whiteness and opacity were measured according to ISO 2470-1977 and ISO 2471-1977, respectively.

object ingredient Basis weight
(g / m ² ) density
(g / cm ³⁾ Thermal insulation
(km) Bekk
Smoothness Internal theft
(time) Whiteness
(ISO)
(%) Opacity
(%) Ash
(weight%) Example 2 Boulders Bleached Pulp 450CSF 63.3 0.56 4.66 11.42 4.76 50 83.3 86.2 0.9 Example 3 Bleached Pulp 300CSF 63.1 0.62 6.62 14.76 5.76 393 82.5 85.2 0.6 Comparative Example 1 Commercial Bleached Pulp, 400CSF 60.5 0.69 6.21 6.00 3.44 566 84.2 73.1 0.2 Comparative Example 2 Commercial Bleached Pulp, 400CSF
10% by weight of calcium carbonate 62.77 0.62 4.16 4.71 2.61 80 84.2 85.5 7.0 Comparative Example 3 Commercial Bleached Pulp, 400CSF
20 wt% added calcium carbonate 62.42 0.63 2.95 4.43 3.15 22 86.7 86.7 17.6

As shown in Table 2, Examples 2 and 3 without the inorganic filler at the same representative basis weight of 60 g / m ² showed a high opacity when compared to Comparative Example 1.

Example 3 made of a bundle of bleached pulp was confirmed to have the same level of opacity compared to Comparative Example 2 in which only 10% by weight of calcium carbonate was added to wood pulp. However, the thermal length was 59%, the heat resistance was 300% Example 3 was excellent, Bekk smoothness was also excellent. In addition, Example 2 showed the same opacity as Comparative Example 3 made of wood pulp, at this time 57%, heat resistance was excellent 120%, smoothness was also very good.

The foregoing description is merely illustrative of the technical idea of the present invention, and various changes and modifications may be made by those skilled in the art without departing from the essential characteristics of the present invention. Therefore, the embodiments disclosed in the present invention are not intended to limit the technical idea of the present invention but to describe the present invention, and the scope of the technical idea of the present invention is not limited by these embodiments. The protection scope of the present invention should be interpreted by the following claims, and all technical ideas within the equivalent scope should be interpreted as being included in the scope of the present invention.

Claims (9)

Preparing a bleached pulp bleached from the parts with an ISO whiteness of at least 70%, and Manufacturing paper from the bleached pulp, wherein the bleached pulp has a fiber coarseness of 0.02 to 0.08 ug / m, an average fiber width of 8 to 15 um, 3 weight percent or less. Method for producing opaque paper using parts containing Klason lignin. The method of claim 1, Genus Typha L. is a perennial herb belonging to Typhaceae selected from the group consisting of Typha orientalis, Typha angustata, Typha latifolia, and mixtures thereof. Method for producing an opaque paper using phosphorus, parts. delete  The method of claim 1,  Preparing paper from the bleached pulp is  Beating puffy bleached pulp fibers;  Sorting and selecting beaten bleached pulp fibers; And  Steps to paper and process selected paper  To include, a method of producing an opaque paper using the parts. The method of claim 4, wherein The step of preparing paper from the bleached pulp is wood pulp in the bleached pulp; Or mixing another non-woody pulp with a second pulp with a bark, flax, hemp, cotton, rice straw, bagasse, or red algae into a second pulp.        The method of claim 5,       The step of mixing the second pulp to the bleached pulp pulp is to mix 10 to 90% by weight of the pulp pulp and 90 to 10% by weight of the second pulp, the method of producing an opaque paper using the parts. The method of claim 6, The wood pulp is any one or more selected from hardwood pulp or coniferous pulp, the method of producing an opaque paper using the parts. delete A low basis weight paper produced according to the method according to any one of claims 1, 2 and 4 to 7.