Grass type un-bleaching pulp, preparation method and use thereof

A technology of unbleached pulp and grasses, applied in the field of unbleached pulp, which can solve the problems of high carbohydrate content, high viscosity of black liquor, difficult recovery, etc., and achieve the effects of reducing dust, high yield and reducing production cost

Active Publication Date: 2009-06-10
SHANDONG TRALIN PAPER
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

3. Due to the high content of silicon and carbohydrates in the raw materials, the viscosity of the black liquor is high and the recovery is difficult
4. Grass fibers contain a large number of miscellaneous cells, which pose a series of hazards to papermaking
Under the serious situation of increasing shortage of forest resources in our country, how to use grass raw materials to prepare high-quality unbleached pulp has not been reported yet.

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0072] The wheat straw raw material is prepared by the conventional dry method and put into the cooking pot, and the cooking liquid is added to the cooking pot. The amount of ammonium sulfite added is 9% of the absolute dry raw material, and the liquid ratio is 1:3. 110°C, keep warm at this temperature for 30 minutes, let off steam for 25 minutes, heat up for 60 minutes to 168°C, and keep warm for 90 minutes. The hardness of the high-hardness pulp obtained after cooking is 22, which is equivalent to a kappa value of 35.5. It is diluted with dilute black liquor to a concentration of 2.5-3.5%, and then screened by screening methods of the prior art such as sieving by skipping. The loss is 0.2-0.5%. Then adopt the three-stage vacuum washing machine in the prior art to wash. After washing, a high-hardness pulp with a concentration of 10% is obtained, and then the pulp is heated to 70° C. by a screw conveyor and transported to a medium-consistency pulp pipe. The pulp is subjected...

Embodiment 2

[0074] After the rice straw raw material is prepared by dry method with a hammer crusher, it is put into a cooking pot, and the cooking liquid is added to the cooking pot. The amount of ammonium sulfite added is 13% of the dry raw material, and the liquid ratio is 1:4. Heating once to 120°C, keeping warm at this temperature for 40 minutes, letting off steam for 25 minutes, heating twice to raise the temperature to 168°C for 90 minutes. The hardness of the high-hardness pulp obtained after cooking is 16, which is equivalent to a Kappa value of 23. It is diluted to a concentration of 2.5-3.5% with dilute black liquor, and then screened by screening methods of the prior art such as skipping screening. The loss is 0.2-0.5%. Then adopt the three-stage vacuum washing machine in the prior art to wash. After washing, a high-hardness pulp with a concentration of 10% is obtained, and then the pulp is heated to 70° C. by a screw conveyor and transported to a medium-consistency pulp pipe...

Embodiment 3

[0076] The bagasse raw material was prepared by dry method and pith removed, then put into the cooking pot, and the cooking liquid was added into the cooking pot. The first heating is to raise the temperature to 130°C, keep the temperature for 20 minutes at this temperature, and let off steam for 20 minutes, and the second heating is to raise the temperature to 165°C for 50 minutes, and keep the temperature for 70 minutes. Cooking to obtain a high-hardness pulp with a hardness of 21 equivalent to a kappa value of 32, and then sending the high-hardness pulp into a twin-roll press for extracting black liquor in the prior art for squeezing. After squeezing, a pulp with a concentration of 32% is obtained. The pulp with high hardness is diluted to 2.5% by black liquor and then sent to the three-stage vacuum pulp washer for washing. The pulp concentration is 10-13%. Thick stock pipe. The pulp is subjected to conditioning treatment in the medium-consistency stock pipe to remove the ...

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Abstract

The invention discloses grass unbleached pulp and a preparation method thereof. The fracture length of the unbleached pulp is between 3.48 and 7.2km, the folding resistance is between 15 and 70 times, the tearability is between 180 and 275 mN, the whiteness is 33 to 48 percent ISO, and the beating degree is between 33 and 38 DEG SR. The unbleached pulp can be taken as pulp of corrugated paper, napkin paper and packing paper. The preparation method comprises the steps of cooking, oxygen delignification and so on, and the unbleached pulp is obtained by obtaining high-hardness pulp the hardness of which has a potassium permanganate value of between 16 and 28 and is equivalent to a Kappa number of between 24 and 50 through the cooking, and then performing oxygen delignification treatment by introducing oxygen and adding sodium hydroxide, or being matched with a pulp squeezing step and / or a disintegration step before the oxygen delignification. The use of the method can not cause the unbleached pulp to be polluted by a bleaching agent, and the strength of the pulp is protected at the same time, thereby preventing cellulose in the pulp from being degraded due to the influence of bleaching.

Description

technical field [0001] The present invention relates to unbleached pulp, more specifically, relates to a grass unbleached pulp, its preparation method and application. Background technique [0002] The methods of producing pulp from plant fibers are: chemical method, mechanical method and chemical mechanical method. In the chemical method, it is divided into lime method, caustic soda method, anthraquinone-caustic soda method and sulfate method. [0003] The main components of paper are cellulose and hemicellulose. There are two kinds of plant fibers used as papermaking raw materials: wood fiber and non-wood fiber. Their main components are cellulose, hemicellulose and lignin. Pulping is a process of removing lignin as much as possible and retaining cellulose and hemicellulose. Wood fiber is a high-quality papermaking raw material and has a great advantage in the papermaking industry. With the rapid development of industry, there is a contradiction between the supply and de...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): D21H11/12D21C3/00D21C7/00D21C3/14D21C3/02D21C9/00
Inventor 李洪法杨吉慧宋明信陈松涛宋建军
Owner SHANDONG TRALIN PAPER
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