CN101492890B

CN101492890B - Method for removing exterior black bark of barks of paper mulberry

Info

Publication number: CN101492890B
Application number: CN2009100214141A
Authority: CN
Inventors: 张素风; 石良; 姜亮
Original assignee: Shaanxi University of Science and Technology
Current assignee: Shaanxi University of Science and Technology
Priority date: 2009-03-06
Filing date: 2009-03-06
Publication date: 2011-05-18
Anticipated expiration: 2029-03-06
Also published as: CN101492890A

Abstract

The invention discloses a method for peeling off black bark on the outside of bark of paper mulberry, the method which combines the pretreatment of hot water with a dual-roller extrusion method is applied to realizing the peeling-off of the outside bark of the bark of paper mulberry. At first, the bark of paper mulberry is subjected to pectin removal and softening treatments in hot water to filter the liquid subsequent to the pretreatments, the bark of paper mulberry is delivered between two relatively rotary cast iron rolls, and the black bark of the bark of paper mulberry can be removed after the extrusion, thus achieving the aim of separating the black bark from phloem. The black bark-peeling rate can reach 80-100% if the method is applied. The invention settles the problem that the black bark on the outside of current bark of paper mulberry is hardly removed, and is convenient and efficient, low in costs and suitable for mass production.

Description

The removal method of exterior black bark of barks of paper mulberry

Technical field

The present invention relates to a kind of removal method of exterior black bark of barks of paper mulberry.

Background technology

Tapa is made up of the extremely strong long fiber of toughness, is the paper fibre material of high-quality, is usually used in making long fiber fine papers such as tea bag paper, china picture-character paper, bank-note paper.In the paper mulberry growth course, its bark top layer can form one deck casting skin shell, and in the production that tapa slurrying utilizes, the removal of this layer casting skin is the difficult point and the emphasis of structure leather slurry and utilization.Because the casting skin of structure skin external surface layer is a cuticula, content of cellulose seldom and contains a large amount of lignins, ash and alcohol-benzene extractive, and lignin wherein mainly is present in the phellem layer cell, the structure of this part lignin is more more complicated than the structure of general lignin, is difficult to during boiling remove; Ash in the casting skin and alcohol benzene extractive also are difficult to remove when slurrying, and in a single day these materials sneak in the structure latex material, will directly cause the decline of stock quality, even cause the bleaching problem on obstacle of later stage slurry.

Traditional tapa pulping technique, in order to ensure the removal of casting skin shell, adopt the hard boiling process route of high-alkali, high temperature, high pressure, long-time insulation during boiling, rely on pretending of chemicals to remove casting skin with dissolving, often cause the gained pulp yield lower, be about 20%.The new technology of Chu Xianing had adopted sodium sulfite-auxiliary agent method and alkaline hydrogen peroxide oxalates (NPO) method afterwards, though improved tapa fiber yield, but need manually remove the peel structure skin exterior black, perhaps directly adopt the white tapa raw material of introducing from Japan.That is to say that the used barking method of tapa source mill mainly is manually to remove the peel with cutter at present.This method has following distinct disadvantage: (1) need with a large amount of manually, labor productivity is low, need employ the staff that peels in a large number; (2) material loss is big, and a large amount of fibers are peelled off with casting skin.

The difficult problem of this exterior black bark of barks of paper mulberry peeling that exists has at present greatly limited the development of the continuous mechanized production of tapa.

Summary of the invention

The objective of the invention is to find a kind of can the peeling fast, can reduce the exterior black bark of barks of paper mulberry mechanical removal methods of structure hide fiber loss again.

For achieving the above object, the technical solution used in the present invention is:

1) at first tapa being placed temperature is 95 ℃ hot water, handles 30 minutes, and stirs once elimination liquid after the preliminary treatment every 5 minutes;

2) pretreated tapa is sent between two cast iron rolls staggered relatively, the casting skin after the cast iron roll extruding in the tapa comes off, and the pressure of cast iron roll is 0.1～0.2Mpa, extruding number of times 2 times.

A roller in two cast iron rolls staggered relatively of the present invention is fixed, and another can move horizontally, to regulate squeeze pressure.

The present invention will do in oxalates or hot water except that pectin and softening the processing with the tapa of casting skin, elimination liquid then, tapa is sent between two counterrotating cast iron rolls, after the two roll-ins of excess pressure are pressed, casting skin meeting fall in flakes, the casting skin of tapa outside can be removed by screening, reach the purpose that casting skin and bast partly separate.This method has solved the problem that existing exterior black bark of barks of paper mulberry is difficult to remove, and simple and effective, with low cost is applicable to continuous mechanized production.

The specific embodiment

Embodiment 1: at first tapa being placed temperature is 80 ℃ oxalate solution, and the mass concentration of oxalates is 3%, handles 60 minutes, and stirs once elimination liquid after the preliminary treatment every 5 minutes; Pretreated tapa is sent between two cast iron rolls staggered relatively, a roller in two cast iron rolls staggered relatively is fixed, another moves horizontally, and the adjusting squeeze pressure is 0.1～0.2Mpa, and the casting skin behind the extruding number of times 3 times in the tapa comes off.

Embodiment 2: at first tapa being placed temperature is 90 ℃ oxalate solution, and the mass concentration of oxalates is 5%, handles 40 minutes, and stirs once elimination liquid after the preliminary treatment every 5 minutes; Pretreated tapa is sent between two cast iron rolls staggered relatively, a roller in two cast iron rolls staggered relatively is fixed, another moves horizontally, and the adjusting squeeze pressure is 0.1～0.2Mpa, and the casting skin behind the extruding number of times 2 times in the tapa comes off.

Embodiment 3: at first tapa being placed temperature is 85 ℃ oxalate solution, and the mass concentration of oxalates is 4%, handles 50 minutes, and stirs once elimination liquid after the preliminary treatment every 5 minutes; Pretreated tapa is sent between two cast iron rolls staggered relatively, a roller in two cast iron rolls staggered relatively is fixed, another moves horizontally, and the adjusting squeeze pressure is 0.1～0.2Mpa, and the casting skin behind the extruding number of times 3 times in the tapa comes off.

Embodiment 4: at first tapa being placed temperature is 95 ℃ hot water, handles 30 minutes, and stirs once elimination liquid after the preliminary treatment every 5 minutes; Pretreated tapa is sent between two cast iron rolls staggered relatively, a roller in two cast iron rolls staggered relatively is fixed, another moves horizontally, and the adjusting squeeze pressure is 0.1～0.2Mpa, and the casting skin behind the extruding number of times 2 times in the tapa comes off.

The present invention is a kind of tapa material papering section treatment process that cleans production that meets, and this advantage of carrying out exterior black bark of barks of paper mulberry removal method is: replace artificial peeling with the mechanical means peeling, can raise labour efficiency more than 4 times, reduced labour cost; Reduce the loss of fiber when removing the peel, improved the yield rate of fiber; Enlarge raw material sources, no matter deceived structure skin or white paper structure, all can be used to processing, the fiber after the peeling, through bleaching, commodity value improves; Gained casting skin and pretreated filtrate are used for the making of other byproduct, are conducive to the abundant comprehensive utilization of structure skin resource.

Claims

1. the removal method of an exterior black bark of barks of paper mulberry is characterized in that:

2. the removal method of exterior black bark of barks of paper mulberry according to claim 1, it is characterized in that: a roller in said two cast iron rolls staggered relatively is fixed, and another can move horizontally, to regulate squeeze pressure.