A kind of production technology of bamboo dissolved pulp
Technical field
The present invention relates to the processing method in textile chemical fiber field, more particularly, the present invention relates to a kind of production technology of bamboo dissolved pulp.
Background technology
Bamboo fibre is a kind of cellulose fibre that extracts from the bamboo of self-sow, is the fifth-largest natural fabric after cotton, fiber crops, hair, silk.Bamboo fibre has air permeability and good, moment water imbibition, stronger ABRASION RESISTANCE and good characteristics such as dyeability, have again simultaneously natural antibacterial, antibacterial, remove mite, deodorization and anti-ultraviolet function.The expert points out that bamboo fibre is a kind of natural environmental-protective type green fiber truly.Bamboo fibre fabric has duplicated the inherent characteristic of bamboo fibre fully because of it, and extremely consumer's favor, product consumption rises year by year.
The present domestic employing prehydrolytic sulfate process boiling technology of bamboo dissolved pulp production Technology, CEH tri-stage bleaching technology.
Above-mentioned technology exists following problem and defective: 1, production cost height, and digester cycle is long, reaches 10-18h, steam energy consumption height, steam consumption quantity is at 10-16 ton/ton slurry; 2, environmental protection is not up to standard, conventional CEH bleaching, and elemental chlorine can produce the carcinogen bioxin, and the industrial water amount is big simultaneously, reaches 120-200m
3/ ton slurry; 3, unstable product quality, the finished product pentose reaches 3-6%, influences lower procedure production.
Application number is 200710050512.9, name is called the patent of invention of " a kind of manufacturing technique of bamboo dissolved pulp ", a kind of manufacturing technique of bamboo dissolved pulp is disclosed, described manufacturing technique comprise in regular turn blank, the screening ash disposal, the mark temperature wash material, sulphate cook, slurries separation, washing, purifying, chlorination, alkali treatment, acetate bleaching+H
2O
2The organic bleaching of oxidation, sour complexing are handled, are manufactured paper with pulp.The present invention has effectively shortened the production procedure of original dissolving pulp, improve the production efficiency of utilizing bamboo wood to produce employed bamboo dissolved pulps such as viscose dissolving pulp, nitrocellulose dissolving pulp, acetate fiber dissolving pulp, cellulose ether dissolving pulp, improved the yield rate that bamboo wood is produced bamboo dissolved pulp simultaneously.
Application number is 200710050512.9, and name is called the patent of invention existing problems of " a kind of manufacturing technique of bamboo dissolved pulp ":
1, auxiliary agent is used in acidic hydrolysis or the steam hydrolysis or the water hydrolysis of cancellation cooking section instead, and the promoter effect of saying in the patent is the lignin in the stripping bamboo material, does not remove with product half fibre that this method is produced, and half fine content height has a strong impact on product quality.
2, bleaching process adopts logical liquid chlorine to carry out chloridized.The elemental chlorine bleaching can produce the carcinogen bioxin, and serious environmental is polluted.
3, patented technology adopts conventional art to no innovative points such as boiling method, energy-saving, emission-reducing, environment friendly aspects.
Summary of the invention
The present invention is intended to solve production cost height in the above-mentioned prior art, and digester cycle is long, and environmental protection is not up to standard, and the problem of unstable product quality provides a kind of cost low, high-quality, the production technology of the bamboo dissolved pulp of environmental protection and energy saving.
In order to realize the foregoing invention purpose, its concrete technical scheme is as follows:
A kind of production technology of bamboo dissolved pulp is characterized in that: comprise following processing step:
A, bamboo chip is washed material, remove impurity such as silt, bamboo ash;
B, the bamboo chip feeding warehouse normal temperature after will washing are stored 4-8h down, according to winter, summer temp difference, suitably adjust the bamboo chip period of storage;
C, steam combine with prehydrolysis and remove half fibre: bamboo chip is added in the digester, directly logical steam carries out gas and steams, logical steam time 30-60min, terminal pressure reaches 0.04-0.06MPa in the pot, be that to add temperature be 50-80 ℃ water to 1:2.5-3.8 in bamboo chip oven dry weight and total liquid weight ratio after the exhaust, be warming up to 150-170 ℃, insulation 30-60min;
D, displacement cooking: add NaOH or the vulcanized sodium of bamboo chip oven dry weight 20-28%, keeping bamboo chip oven dry weight and total liquid weight ratio is 1:2.5-3.8, with add entry among the step C after consistent; Sulphidity is 18-24%; Carry out 2-3 exhaust, each evacuation time is 20-40min, is warming up to 120-140 ℃ after having arranged, insulation 30-60min; Be warming up to 160-175 ℃ again, insulation 60-90min;
E, closed screening the pulp: screen out big impurity with jumping, carry out slurries with press master and vacuum pulp washing machine and separate, the black liquid wave hairdressing after the separation is that 8-10 ° of B é, temperature are 80-90 ℃, the residual alkali≤0.1g/l in the thick slurry; Screen out the slurry silk with meeting, desander removes sandstone dust impurity, concentrates with vacuum pulp washing machine or decker at last, and being concentrated to the slurry concentration expressed in percentage by weight is 3-6%;
F, oxygen-alkali bleaching: add NaOH, the pH value of sizing mixing is 12-13, and slurry concentration 9-15% with the pressure aerating oxygen of 0.8-1.2Mpa, bleaches 30-60min down at 90-120 ℃;
G, salt acid treatment: the 1.5-3% by slurry weight adds hydrochloric acid, 35-40 ℃ of following acid treatment 20-60min; Described hydrochloric acid addition is to calculate according to 100% hydrochloric acid;
H, manufacture paper with pulp, rinsing step water: finished product is manufactured paper with pulp, and unnecessary rare plain boiled water is used for slurry and bleaching back slurry after the salt acid treatment in the process of manufacturing paper with pulp.
The useful technique effect that the present invention brings:
One, the advantage of the operation of steps A: the easy and alkali association reaction of bamboo ash in the bamboo material increases alkali consumption; Bamboo ash and alkali reaction, cooking liquor viscosity increases, and reduces the infiltration diffusion of cooking liquor to fibrous inside, prolongs digester cycle, causes half steaming even; Silt, the incomplete slurry silk of reaction cause finished product dust to increase in the bamboo material; So wash the generation that can effectively prevent above-mentioned situation behind the material;
Two, step B the advantage of storage operation: balance bamboo chip moisture, be beneficial to boiling, be beneficial to simultaneously to produce to regulate and arrange;
Three, the advantage that combines with prehydrolysis of step C steam: prehydrolysis is more even, improves half fine clearance; Shorten the prehydrolysis time, improve work production efficiency;
Four, the advantage of step D displacement cooking operation: sulfate process displacement cooking technology, the totally-enclosed heat reclaiming system of displacement cooking can be saved steam more than 30%, energy-saving and emission-reduction, environmental protection; Displacement cooking can obtain the low kappa number slurry, is easy to bleaching, saves bleaching agent; The slurry that displacement cooking obtains is more even, can produce high-quality product;
Five, the advantage of the closed screening the pulp of step e: remove impurity such as slurry silk, sandstone in the slurry simultaneously; Press master combines with vacuum pulp washing machine, at utmost carries out slurries and separates, and improves Baume degrees, the temperature of black liquor, is beneficial to the burning of black liquor, reduces the residual alkali that slurries separate the thick slurry in back simultaneously, helps the processing of back operation, alleviates the middle-stage wastewater processing pressure; Dash slurry usefulness after the waste water recycling that vacuum pulp washing machine or decker concentrate separates to slurries, accomplish that water circulation uses, the minimizing discharge of wastewater is beneficial to environmental protection;
Six, the advantage of step F chlorine-free bleaching: bleaching time is short, and operation is simple, and chlorine-free bleaching is environmental protection very;
Seven, the advantage of step H rinsing step water: the unnecessary rare plain boiled water of paper machine is back to use acid treatment final vacuum wash engine slurry, and the waste water after the washing is back to use bleaching back slurry again, and water accomplishes that step recycles, and reduces water consumption;
Eight, the present invention produces bamboo dissolved pulp, and good product quality can be produced in viscosity 8-16mPa.s scope according to demand, the fluctuation of the product viscosity of production can be controlled in ± the 0.2mPa.s scope in, viscosity is even; The fine content height of first can reach more than 94%; The whiteness height, whiteness is difficult for brightness reversion more than 80%; Pentose≤3%, pentose content is low; Reactivity worth≤250s(5mlCS2), reactivity worth is good, is beneficial to the production of back operation;
Nine, the bamboo dissolved pulp produced of this technology conventional art on year-on-year basis can reduce steam consumption quantity 3-5 ton/ton slurry, water minimizing 40-100m
3/ ton slurry reaches 60m
3In/ton pulp waste water the discharge standard, chlorine-free bleaching, environment-friendly and green production.
The specific embodiment
Embodiment 1
A, bamboo chip is washed material, remove impurity such as silt, bamboo ash;
B, the bamboo chip feeding warehouse normal temperature after will washing are stored 4h down, according to winter, summer temp difference, suitably adjust the bamboo chip period of storage;
C, steam combine with prehydrolysis and remove half fibre: bamboo chip is added in the digester, directly logical steam carries out gas and steams, logical steam time 30min, terminal pressure reaches 0.04MPa in the pot, be that to add temperature be 50 ℃ water to 1:2.5 in bamboo chip oven dry weight and total liquid weight ratio after the exhaust, be warming up to 150 ℃, insulation 30min;
D, displacement cooking: add the NaOH or the vulcanized sodium of bamboo chip oven dry weight 20%, keeping bamboo chip oven dry weight and total liquid weight ratio is 1:2.5, and sulphidity is 18%; Carry out 2 exhausts, each evacuation time is 20min, is warming up to 120 ℃ after having arranged, insulation 30min; Be warming up to 160 ℃ again, insulation 60min;
E, closed screening the pulp: screen out big impurity with jumping, carry out slurries with press master and vacuum pulp washing machine and separate, the black liquid wave hairdressing after the separation is that 8 ° of B é, temperature are 80 ℃, the residual alkali 0.02g/l in the thick slurry; Screen out the slurry silk with meeting, desander removes sandstone dust impurity, concentrates with vacuum pulp washing machine at last, and being concentrated to the slurry concentration expressed in percentage by weight is 3%;
F, oxygen-alkali bleaching: add NaOH, the pH value of sizing mixing is 12, and slurry concentration 9% with the pressure aerating oxygen of 0.8Mpa, is bleached 30min down at 90 ℃;
G, salt acid treatment: add hydrochloric acid, 35 ℃ of following acid treatment 20min by 1.5% of slurry weight; Described hydrochloric acid addition is to calculate according to 100% hydrochloric acid;
H, manufacture paper with pulp, rinsing step water: finished product is manufactured paper with pulp, and unnecessary rare plain boiled water is used for slurry and bleaching back slurry after the salt acid treatment in the process of manufacturing paper with pulp.
Embodiment 2
A, bamboo chip is washed material, remove impurity such as silt, bamboo ash;
B, the bamboo chip feeding warehouse normal temperature after will washing are stored 8h down, according to winter, summer temp difference, suitably adjust the bamboo chip period of storage;
C, steam combine with prehydrolysis and remove half fibre: bamboo chip is added in the digester, directly logical steam carries out gas and steams, logical steam time 60min, terminal pressure reaches 0.06MPa in the pot, be that to add temperature be 80 ℃ water to 1:3.8 in bamboo chip oven dry weight and total liquid weight ratio after the exhaust, be warming up to 170 ℃, insulation 60min;
D, displacement cooking: add the NaOH or the vulcanized sodium of bamboo chip oven dry weight 28%, keeping bamboo chip oven dry weight and total liquid weight ratio is 1:3.8, and sulphidity is 24%; Carry out 3 exhausts, each evacuation time is 40min, is warming up to 140 ℃ after having arranged, insulation 60min; Be warming up to 175 ℃ again, insulation 90min;
E, closed screening the pulp: screen out big impurity with jumping, carry out slurries with press master and vacuum pulp washing machine and separate, the black liquid wave hairdressing after the separation is that 10 ° of B é, temperature are 90 ℃, the residual alkali 0.1g/l in the thick slurry; Screen out the slurry silk with meeting, desander removes sandstone dust impurity, concentrates with decker at last, and being concentrated to the slurry concentration expressed in percentage by weight is 6%;
F, oxygen-alkali bleaching: add NaOH, the pH value of sizing mixing is 13, and slurry concentration 15% with the pressure aerating oxygen of 1.2Mpa, is bleached 60min down at 120 ℃;
G, salt acid treatment: add hydrochloric acid, 40 ℃ of following acid treatment 60min by 3% of slurry weight; Described hydrochloric acid addition is to calculate according to 100% hydrochloric acid;
H, manufacture paper with pulp, rinsing step water: finished product is manufactured paper with pulp, and unnecessary rare plain boiled water is used for slurry and bleaching back slurry after the salt acid treatment in the process of manufacturing paper with pulp.
Embodiment 3
A, bamboo chip is washed material, remove impurity such as silt, bamboo ash;
B, the bamboo chip feeding warehouse normal temperature after will washing are stored 6h down, according to winter, summer temp difference, suitably adjust the bamboo chip period of storage;
C, steam combine with prehydrolysis and remove half fibre: bamboo chip is added in the digester, directly logical steam carries out gas and steams, logical steam time 45min, terminal pressure reaches 0.05MPa in the pot, be that to add temperature be 65 ℃ water to 1:3.2 in bamboo chip oven dry weight and total liquid weight ratio after the exhaust, be warming up to 160 ℃, insulation 45min;
D, displacement cooking: add the NaOH or the vulcanized sodium of bamboo chip oven dry weight 24%, keeping bamboo chip oven dry weight and total liquid weight ratio is 1:3.2, and sulphidity is 21%; Carry out 3 exhausts, each evacuation time is 30min, is warming up to 130 ℃ after having arranged, insulation 45min; Be warming up to 167 ℃ again, insulation 75min;
E, closed screening the pulp: screen out big impurity with jumping, carry out slurries with press master and vacuum pulp washing machine and separate, the black liquid wave hairdressing after the separation is that 9 ° of B é, temperature are 85 ℃, the residual alkali 0.06g/l in the thick slurry; Screen out the slurry silk with meeting, desander removes sandstone dust impurity, concentrates with decker at last, and being concentrated to the slurry concentration expressed in percentage by weight is 4.5%;
F, oxygen-alkali bleaching: add NaOH, the pH value of sizing mixing is 12.5, and slurry concentration 12% with the pressure aerating oxygen of 1.0Mpa, is bleached 45min down at 105 ℃;
G, salt acid treatment: add hydrochloric acid, 38 ℃ of following acid treatment 40min by 2.3% of slurry weight; Described hydrochloric acid addition is to calculate according to 100% hydrochloric acid;
H, manufacture paper with pulp, rinsing step water: finished product is manufactured paper with pulp, and unnecessary rare plain boiled water is used for slurry and bleaching back slurry after the salt acid treatment in the process of manufacturing paper with pulp.
Embodiment 4
A, bamboo chip is washed material, remove impurity such as silt, bamboo ash;
B, the bamboo chip feeding warehouse normal temperature after will washing are stored 7h down, according to winter, summer temp difference, suitably adjust the bamboo chip period of storage;
C, steam combine with prehydrolysis and remove half fibre: bamboo chip is added in the digester, directly logical steam carries out gas and steams, logical steam time 60min, terminal pressure reaches 0.04MPa in the pot, be that to add temperature be 75 ℃ water to 1:2.7 in bamboo chip oven dry weight and total liquid weight ratio after the exhaust, be warming up to 170 ℃, insulation 30min;
D, displacement cooking: add the NaOH or the vulcanized sodium of bamboo chip oven dry weight 22%, keeping bamboo chip oven dry weight and total liquid weight ratio is 1:2.7, and sulphidity is 24%; Carry out 2 exhausts, each evacuation time is 25min, is warming up to 135 ℃ after having arranged, insulation 50min; Be warming up to 165 ℃ again, insulation 80min;
E, closed screening the pulp: screen out big impurity with jumping, carry out slurries with press master and vacuum pulp washing machine and separate, the black liquid wave hairdressing after the separation is that 8 ° of B é, temperature are 88 ℃, the residual alkali 0.05g/l in the thick slurry; Screen out the slurry silk with meeting, desander removes sandstone dust impurity, concentrates with vacuum pulp washing machine at last, and being concentrated to the slurry concentration expressed in percentage by weight is 5%;
F, oxygen-alkali bleaching: add NaOH, the pH value of sizing mixing is 13, and slurry concentration 10% with the pressure aerating oxygen of 1.1Mpa, is bleached 55min down at 100 ℃;
G, salt acid treatment: add hydrochloric acid, 36 ℃ of following acid treatment 40min by 2.5% of slurry weight; Described hydrochloric acid addition is to calculate according to 100% hydrochloric acid;
H, manufacture paper with pulp, rinsing step water: finished product is manufactured paper with pulp, and unnecessary rare plain boiled water is used for slurry and bleaching back slurry after the salt acid treatment in the process of manufacturing paper with pulp.