CN1865583A - Pulping process for mixed Devil's Rush herb and reed - Google Patents

Abstract

The invention discloses a composite pulping technology of Chinese alpine rush and reed, which comprises the following steps: 1. putting the cut Chinese alpine rush and reed in the boiler according to proportion; 2. adopting sulphate process to boil; 3. washing through four-segmented back flow; 4. removing large slag, vine, sand and other dusts; 5. adopting CEHP four-segmented bleaching technology; 6. storing semi-finished product slurry in the slurry tower to send to paper making department through pump. The invention broadens the source of raw material to satisfy normal need of produce, which possesses excellent quality and economical value.

Description

A kind of Chinese alpine rush and reed pulping process for mixed

One, technical field:

The present invention relates to the paper-making pulping field, particularly relate to the technology of a kind of Chinese alpine rush and reed mixed pulp.

Two, background technology:

Along with China's rapid development of economy, the raising of living standards of the people, China's paper and cardboard consumption figure annual average rate of increase reach 10%, are 3～4 times of world's annual average rate of increase, and last year, consumption figure reached about 5,400 ten thousand tons.According to relevant department's scholarly forecast, will reach 7,000 ten thousand tons to national paper in 2007 and cardboard consumption figure, 9,000 ten thousand tons of consumption figures will be arranged by 2010, this proves absolutely that China's paper industry has enormous and latent market and development space.Growing along with the papermaking industry, paper output significantly increases, and papermaking raw material demand also significantly increases, and China's papermaking raw material are based on grass as raw material, and the grass as raw material competition is very fierce; China is a scarce woods Shaolin country, and it is unrealistic to cut down timber papermaking in a large number, so just needs the raw-material appearance of new papermaking.

Three, summary of the invention:

The purpose of this invention is to provide a kind of Chinese alpine rush and reed pulping process for mixed, widen the raw-material source of papermaking, stabilize the reed disparities between supply and demand, to satisfy the needs of ordinary production.

The technical solution used in the present invention comprises the steps:

1. with the rotor chaffcutter Chinese alpine rush being cut into length is 35～55mm, and cutting the reed machine with cutterhead, reed is cut into length is 25～40mm, sends into digester in the ratio of Chinese alpine rush and reed 1: 1～2 simultaneously with belt;

2. adopt kraft cooking, cooking liquor is than about 1: 4.5, digestion time about every pot 1 hour, alkali is than 15～16%, sulphidity 14～16%, directly admission boiling is in earlier stage advanced big vapour, maximum pressure is 0.38～0.44MPa; The kettle temperature difference must be even, and 3 temperature in upper, middle and lower are approaching, and thermal convection current wants fast in the pot, and the final stage of cooking temperature of lower will grow steadily;

3. adopt four sections countercurrent washings, wash the residual alkali in back≤12mg/g slurry, black liquor Baume 〉=6.6 ⁰Be;

4. adopt pulp screen to remove big bits, pressurized screen is removed the vine in the reed, and desander is removed silt particle and other dust that Chinese alpine rush and reed bring;

5. adopt CEHP four sectional bleaching process, whiteness 80～83%ISO, dust≤240mm ²/ kg, tear index is at 5.7mN.m ²More than/the g;

6. the semi-finished product slurry is stored in the pulp storage tower, again the pumping paper machine room.

The lignin content of Chinese alpine rush is low, is generally 12～13%, is up to 16.4%, far below poplar (23.9%), pine (37.4%) and wheat straw, reed etc.; The principal character of Chinese alpine rush fiber is carefully to grow, and fibre length reaches 2.1 millimeters, and is longer than reed (1.69 millimeters), is only second to pine; The fiber length-width ratio is 200, far above 67 of 117 and the Korean pine of reed.The heteroproteose cell of Chinese alpine rush lacks than other grass as raw material, accounts for 30% (reed reed 34.5%, bagasse 35.7%) of the gross area, and this also is one of principal character of Chinese alpine rush.

Chinese alpine rush fiber softening, matter are tough, the quality comprehensive index is omited inferior to the first-class paper grade (stock) timber such as Korean pine except that fibre length, pulping deflection, be better than general needlebush such as leaf wood such as willow, birch and wet-land pine tree, and because its lignin content is low, heteroproteose cell content is low etc. characteristic, the slurrying alkali charge is few, energy consumption is low, the slurrying integrated cost is than wood pulp low 30～50%, approaching substantially with reed slurrying cost, be paper making raw materials rare, super quality and competitive price.

The Chinese alpine rush pulp fibres is elongated, and heteroproteose cell content is few, is used for substituting or part substitutes long fiber pulp and joins that to copy high-quality wood-free paper evenness good, and the surface quality height joins especially that to copy the wrapping paper printability very good.

The present invention adopts vertical digester that Chinese alpine rush and reed are carried out hodgepodge, other technological process is consistent with the production reed pulp, need not to carry out scrap build, thereby widened the raw material source, the reed disparities between supply and demand have been stabilized, to satisfy the needs of ordinary production, stock quality is good, and good economic worth and resource value are arranged.

Four, the specific embodiment:

The present invention is further described below in conjunction with embodiment:

The present invention adopts the mixed pulp of sulfate process vertical digester boiling Chinese alpine rush and reed, and production technology and reed pulping process are basic identical, and the critical process of Chinese alpine rush and reed mixed pulp is boiling, and each operation specific requirement is described as follows:

1, get the raw materials ready:

With the rotor chaffcutter Chinese alpine rush being cut into length is 35～55mm; Cutting the reed machine with cutterhead simultaneously, reed is cut into length is 25～40mm, and Chinese alpine rush contains assorted few, does not need directly to send into digester simultaneously with the reed through dedusting through dust pelletizing system;

2, boiling:

Adopt kraft cooking, digestion time about every pot 1 hour, alkali is than 15～16%, sulphidity 14～16%, direct admission boiling;

1) control of liquor ratio: cooking liquor is than necessary bigger than normal, generally to be controlled at about 1: 4.5, because the epidermis of Chinese alpine rush is thinner than reed, it is faster than reed that its large tracts of land is inhaled alkali in the intensification process of osmosis, and liquor ratio is little will to be caused a pot interior part not have soup to permeate and go out raw cook;

2) heating rate control: heat up early stage and can not advance little vapour, can only advance big vapour, otherwise tablet is even because of seething not enough half steaming, goes out raw cook easily;

3) dress pot amount control: dress pot amount can not be too high, leave suitable space.Because of the Chinese alpine rush softness, dress pot density is big, if it is too high to adorn the pot amount, remaining space is not enough in the pot, is unfavorable for that a pot inner liquid medicine seethes, and is easy to produce local boiling and goes out raw cook inadequately;

4) control of pressure: because of the Chinese alpine rush epidermis approaches, suction alkali is fast, reaction speed is also fast, maximum pressure is 0.4～0.5MPa when the boiling reed pulp, then maximum pressure is reduced to 0.38～0.44MPa when producing the Chinese alpine rush slurry, purpose is to make fiber degradation severity in order to prevent because of over-cooking, and fibre length, intensity are subjected to obvious influence;

5) temperature controlling: because of soup quick permeation in Chinese alpine rush, reaction speed is fast, so the kettle temperature difference must be even, 3 temperature in upper, middle and lower are approaching, and thermal convection current wants fast in the pot, and the final stage of cooking temperature of lower will grow steadily, if straight line rises, then can not put pot immediately;

3, washing:

Adopt four sections countercurrent washings, wash the residual alkali in back≤12mg/g slurry, black liquor Baume 〉=6.6 ⁰Be, because the drainability of Chinese alpine rush is good than reed, easier the carrying out of mixed pulp washing of Chinese alpine rush and reed, clean result is better;

4, screening:

Adopt pulp screen to remove big bits, pressurized screen is removed the vine in the reed, and desander is removed silt particle and other dust that Chinese alpine rush and reed bring;

5, bleaching:

Adopt CEHP four sectional bleaching process, whiteness 80～83%ISO, dust≤240mm ²/ kg, tear index is at 5.7mN.m ²More than/the g;

6, semi-finished product are stored:

The semi-finished product slurry is stored in the pulp storage tower, again the pumping paper machine room.

Claims (1)

1, a kind of Chinese alpine rush and reed pulping process for mixed is characterized in that comprising the steps:

1. with the rotor chaffcutter Chinese alpine rush being cut into length is 35～55mm, and reed is cut into length is 25～40mm with cutting the reed machine, sends into digester in the ratio of Chinese alpine rush and reed 1: 1～2 simultaneously with belt;

2. adopt kraft cooking, cooking liquor is than about 1: 4.5, digestion time about every pot 1 hour, alkali is than 15～16%, sulphidity 14～16%, directly admission boiling, advance big vapour early stage, and maximum pressure is 0.38～0.44MPa, the kettle temperature difference must be even, 3 temperature in upper, middle and lower are approaching, and thermal convection current wants fast in the pot, and the final stage of cooking temperature of lower will grow steadily;

3. adopt four sections countercurrent washings then, wash the residual alkali in back≤12mg/g slurry, black liquor Baume 〉=6.60Be;

4. adopt pulp screen to remove big bits again, pressurized screen is removed the vine in the reed, and desander is removed silt particle and other dust that Chinese alpine rush and reed bring;

5. adopt CEHP four sectional bleaching process, whiteness 80～83%ISO, dust≤240mm ²/ kg, tear index is at 5.75.7mN.m ²More than/the g;

6. the semi-finished product slurry is stored in the pulp storage tower, again the pumping paper machine room.