Background technology
Development along with China's viscose industry, domestic enterprise is many with the raw materials for production of the cotton pulp dregs of rice as viscose, the resource of raw material cotton linter be subjected to cultivated area and growth cycle restriction and day by day the shortage, because grain and cotton is striven the outstanding of ground contradiction, the influence of the long period and the ecological balance has seriously restricted the development of China's viscose industry.Existing for this reason enterprise is used for viscose glue production with dissolving pulp, but the high fluctuation of the price of import dissolving pulp is big, has influenced the normal operation and the economic benefit of enterprise, seeks the substitute of dissolving pulp, is a vital task of enterprise.
China has produced voluntarily with import a large amount of papermaking level wood-pulp boards at present, but owing to has shortcomings such as viscosity height, reactivity worth difference and non-cellulosic impurity content height.Directly can't be used for the production of viscose with the wood pulp of papermaking level wood-pulp board production.Only a few enterprise attempts with the raw materials for production of bamboo pulp as viscose, and has obtained initial success, is CN02112175.3 as the patent No., and the patent of invention that name is called " bamboo pulp denatured productive technology " discloses a kind of production technology of bamboo pulp.But the bamboo fibre average length is lower than the papermaking xylon, production process is because of its ash, pentosan content height, and bamboo fibrid matter is hard, thick walled fiber is more, lumen is narrow, fibr tissue is fine and close, have air in the cell and cause shortcomings such as dissolving difficulty, chemical industry material consumption are big, cost height.
200610021387.4 patent application specification discloses a kind of Wood pomace modified producing technology, and the papermaking level wood-pulp board is produced the wood pulps that is used for viscose through sex change.Its processing step is: wood-pulp board paging, alkali steeping, discongest dispersion, boiling, washing, removal of impurities, bleaching, secondary washing, copy the dregs of rice.Wherein, wood-pulp board paging, alkali steeping, discongest disperse be with the papermaking level wood-pulp board through paging device one by one separately after, spray through alkali, carry the feeding cyclone separator by belt, discongest dispersion with agitator, send into pressafiner and push infiltration, technological parameter is: alkali charge is pressed wood-pulp board weight percent meter 6-17%, bath raio 1: 3-4.
The problem that above-mentioned Wood pomace modified producing technology exists is:
1, the spray mode is carried out alkali steeping: easily cause the wood-pulp board dipping inhomogeneous, especially the part that contacts with conveyer can not be flooded by alkali lye especially; Block pulpboard causes cyclone separator to stop up and discongests and disperse inequality.
2, dipping is 30g/l with the concentration of alkali, and concentration low reaction speed is slow, can not be with hemicellulose stripping in the wood-pulp board.
3, pressafiner extruding: the pitch of pressafiner equates, alkali lye further can not be pushed, infiltrates into fibrous inside, and degradation reaction is insufficient and fall poly-difficulty when causing boiling.
4, liquid initial temperature too high (〉=80 ℃) is boiled in boiling, and seepage velocity is fast, easy oxidative damage fiber and reduce the fine content of first before little steam bleeding; Do not add digestant before the boiling, easily cause half steaming even; Only be alkaline cooking, technology is single, and wood-pulp board is selected narrow range for use.
5, bleaching process is for transferring alkali-bleaching method, and technical process is simple, only is applicable to the needlebush pulpboard that lignin content is low relatively and is not suitable for the leaf wood pulpboard that lignin content is high relatively, fiber is short, and wood-pulp board is selected narrow range for use.
To sum up, above-mentioned existing sex change wood pulps production technology exists that wood-pulp board dipping is uneven, the hemicellulose stripping is slow, fall poly-difficulty, half steaming is even, boiling method is single, method for bleaching is single and condition is violent, wood-pulp board is selected deficiencies such as narrow range for use.
Yet the papermaking level wood-pulp board has dissimilar products according to different working conditions and technology, and wherein the needlebush pulpboard is exactly that wherein a kind of, different sex change production process of papermaking level wood-pulp board has different production requirements.The needlebush pulpboard has the individual character difference equally, is carrying out need providing denatured technology pointedly when sex change is produced.
Summary of the invention
Deficiencies such as the above-mentioned just existing sex change wood pulps production technology of technical problem to be solved by this invention exists that wood-pulp board dipping is uneven, the hemicellulose stripping is slow, falls poly-difficulty, half steaming is even, boiling method is single, method for bleaching is single and condition is violent.It is that the viscose of solubility is with the method for wood pulps, especially at the modified production process of papermaking level needlebush pulpboard that the production of the insoluble papermaking level wood-pulp board of a kind of usefulness is provided.
For solving the problems of the technologies described above, the technical solution used in the present invention is as follows:
The modified production process of papermaking level needlebush pulpboard is characterized in that may further comprise the steps: wood-pulp board paging, alkali steeping, squeeze, discongest dispersion, boiling, washing, removal of impurities, bleaching, secondary washing, copy the dregs of rice; Wherein, it is after papermaking level needlebush pulpboard is separated one by one that described wood-pulp board paging, alkali steeping, squeezing are discongested, sending into concentration is in the alkali steeping bucket of 6%-18%, after flooding into concentration and being the slurry congee of 3%-6%, is pumped into the squeezer extruding and discongests loosen collagen fibre with slurry congee.
Beneficial effect of the present invention shows:
One, the present invention produces the viscose production wood pulps of solubility with insoluble paper-making-stage wood pulp plate denaturalization, and every index can match in excellence or beauty with cotton pulp dregs of rice index with similar viscose, and its quality index is:
Index |
Before the sex change |
After the sex change |
200610021387.4 patent |
The cotton pulp dregs of rice |
Viscosity (Mpa.s) |
38.1 |
12.3 |
14.0 |
11.6 |
First fibre (%) |
≤87.5 |
≥91.8 |
≤88.7 |
≥96.0 |
Ash (%) |
≤0.09 |
≤0.09 |
≤0.15 |
≤0.06 |
Fe(ppm) |
≤10.5 |
≤9.0 |
≤10.0 |
≤10.0 |
Whiteness (%) |
≥87 |
≥88 |
≥88 |
≥82 |
Reactivity worth 7mlCS
2(S)
|
Not enough 25ml |
≤59 |
≤100 |
≤25 |
S10(%) |
13.9 |
9.7 |
12.5 |
4.1 |
S18(%) |
12.5 |
6.5 |
8.6 |
1.7 |
Two, the wood pulps quality index that adopts the present invention to produce has reached the requirement of dissolving grade wood pulp, can meet the production requirement of viscose fully, and the production cost reduction, is not subjected to the influence of foreign price fluctuation.With respect to cotton pulp production, bamboo pulp production, do not increase new environmental factor, waste water becomes yellow liquor by black liquor, and yellow liquor can be used further to boiling, has reduced the pollution of environment; The real realization protected environment, built a harmonious society.
Three, compare with 200610021387.4 patents, its advantage is:
1, impregnation method: in the impregnating equipment of belt stirrer, with concentration is the NaOH dipping pulping congee of 6%-18% (64g/l-235.5g/l), slurry congee concentration is 3%-6%%, make the wood-pulp board dipping evenly, fully, and abundant stripping hemicellulose, the dipping back carries slurry congee conveniently not stop up conveying equipment with pump.
2, squeezing mode: adopt mandatory squeezing, alkali lye further can be pushed, infiltrates into fibrous inside, it is poly-easy and even to fall during boiling, simultaneously alkali lye unnecessary, that contain hemicellulose is extruded the fine content of the wood pulp first that helps purifying.
3, digesting technoloy: cooking liquor initial temperature low relatively (〉=40 ℃), slowly intensification is difficult for oxidized fibre and improves the fine content of first; Add digestant before the boiling, guarantee that boiling is even; Adopt the boiling method of caustic soda, sulfate, sulphite, the total alkali concn 40-120g/l of cooking liquor, total acid consumption 5-9%, holding temperature is controlled at 135-172 ℃ of scope, and the boiling mode is many, process combination is suitable for all papermaking level wood-pulp boards by force.
4, bleaching process: both can adopt the combined type tri-stage bleaching of " chlorination---alkali treatment---hypochlorite bleaching ", and can adopt " chlorination---alkali treatment---H again
2O
2Bleaching " the combined type tri-stage bleaching, under the mitigation condition, further remove delignification and purification first fibre, process combination is strong and be suitable for all papermaking level wood-pulp boards.
5, in a word, technology of the present invention can solve effectively that the wood-pulp board dipping that exists in the existing property wood pulps production process is uneven, the hemicellulose stripping is slow, fall poly-difficulty, half steaming is even, boiling method is single, method for bleaching is single and condition is violent, thereby make the quality of dissolving grade viscose wood pulps more excellent, more stable, be more suitable for the sex change production of papermaking level needlebush pulpboard.
The specific embodiment
Wood pomace modified producing technology step of the present invention is:
Pulpboard paging → alkali steeping → squeeze → discongest dispersion → boiling → washing → removal of impurities → bleaching → secondary washing → copy dregs of rice.
Wherein, described wood-pulp board paging, alkali steeping, squeezing discongest be with the papermaking level wood-pulp board through paging device one by one separately after, after the NaOH of 6%-16% floods into the slurry congee that concentration is 3%-6%, be pumped into squeezer with slurry congee and push and discongest loosen collagen fibre.
Described boiling is meant adopts soda processes (NaOH), sulfate process (NaOH+Na with the papermaking level wood-pulp board
2S), sulphite process (Na
2SO
3+ NaOH) carry out boiling, process conditions are: (1) soda processes, the total alkali concn 40-120g/l of kraft cooking liquid, liquor ratio 1: 2.5-4.0; Sulfite cooking liquid total acid consumption 5-9%, liquor ratio 1: 3.0-4.0; (2) cooking liquor initial temperature 〉=40 ℃; (3) heated up in advance 10-15 minute, to 105 ± 5 ℃; (4) stop behind the vapour dry run again 25~30 minutes; (5) adopt 3 times with interior little steam bleeding (the intensification number of times is decided on little steam bleeding number of times); (6) holding temperature 135-172 ℃, in the 2 hours total times of heating up.
Described washing is to wash material again to residual alkali≤100g/m3 after the wood pulp slurry after boiling is finished is delivered to extrusion equipment extraction yellow liquor from the batch turning pond.
Described removal of impurities is to utilize desander to carry out gravity desanding, centrifugal removal of impurities, starches the dense 0.4-1.0% of being controlled to be, desander advances to starch pressure 0.28-0.32Mpa.
Described blanching step comprises: chlorination, alkali treatment, hypochlorite bleaching, dechlorination and acid treatment, and not only can adopt tri-stage bleaching, but also can adopt single stage bleaching, technical parameter is: chlorination is led to chlorine dose 0.3-0.7%, is transferred alkali number 50-100g/m
3, bleaching temperature≤50 ℃, bleaching chlorine dosage by slurry volume than the hypochlorite/H that adds 0.3-0.8g/l
2O
2Bleaching agent is extraordinarily gone into the hypo dechlorination by 1.5~2.0 of residual chlorine dose in the slurry, is 1~2% to add hydrochloric acid and carry out acid treatment by the percentage by weight of slurry.
Described secondary washing is that the pH value of adjustment slurry is 6-9.
The described dregs of rice of copying are that the slurry of concentration≤1.5% is copied into dissolving pulp 600 * 800mm, that can store behind wet end, press section, drying section.
Below be that paper-making-stage wood pulp plate denaturalization is dissolving grade viscose fiber filament and short silk pulp quality standard:
Dissolving grade viscose fiber filament pulp quality standard
Dissolving grade viscose short fiber pulp quality standard
To help to understand the present invention by following embodiment:
Embodiment 1: soda processes one
1, uses papermaking level needlebush pulpboard 6000Kg, through the paging device paging.
2, the NaOH with 8% (6-12) floods into the slurry congee that concentration is 4.5% (3-6).
3, with slurry congee pump it is sent into the squeezer extruding and discongests loosen collagen fibre.
4, the wood pulp after will squeezing drops in the boiling vessel and carries out boiling, and process conditions are: (1) digestant: NaOH, the total alkali concn 100g/l of cooking liquor (80-120), liquor ratio 1: 2.5 (2.5-3.5); (2) cooking liquor initial temperature 〉=40 ℃; (3) heated up in advance 10-15 minute, to 105 ± 5 ℃; (4) stop behind the vapour dry run again 25~30 minutes; (5) adopt 4 heating curves of 3 little steam bleedings, heat up 2 hours total times; (6) 140 ± 2 ℃ of holding temperatures (138-160).
5, the above-mentioned wood pulp slurry that obtains through boiling is delivered to extruding from the batch turning pond and washed material extraction yellow liquor, washing is to residual alkali≤100g/m3; Utilize desander to carry out centrifugal removal of impurities, starch the dense 0.4-0.8% of being controlled to be, advance to starch pressure 0.28-0.31Mpa.
6, adopt chlorination-alkali treatment-hypochlorite to bleach for three sections then, technical parameter is: chlorination is led to chlorine dose 0.4-0.5% (0.4-0.6), is transferred alkali number 80-100g/m
3, bleaching temperature≤50 ℃, bleaching chlorine dosage than the sodium hypochlorite bleaching agent that adds 0.5g/l (0.3-0.7), extraordinarily go into hypo dechlorination by 2.0 of residual chlorine dose in the slurry by slurry volume, are 1.5% to add hydrochloric acid and carry out acid treatment by the percentage by weight of slurry.
7, secondary washing is washed till slurry pH value 6-9
8, the wood pulp that obtains after the secondary washing is manufactured paper with pulp be the pulp of specification 600 * 800mm.
Embodiment 2: soda processes two
1, uses papermaking level needlebush pulpboard 6000Kg, through the paging device paging.
2, the NaOH with 10% (6-12) floods into the slurry congee that concentration is 3.5% (3-6).
3, with slurry congee pump it is sent into the squeezer extruding and discongests loosen collagen fibre.
4, the wood pulp after will squeezing drops in the boiling vessel and carries out boiling, and process conditions are: (1) digestant: NaOH, the total alkali concn 80g/l of cooking liquor (80-120), liquor ratio 1: 2.5 (2.5-3.5); (2) cooking liquor initial temperature 〉=40 ℃; (3) heated up in advance 10-15 minute, to 105 ± 5 ℃; (4) stop behind the vapour dry run again 25~30 minutes; (5) adopt 4 heating curves of 3 little steam bleedings, heat up 2 hours total times; (6) 160 ± 2 ℃ of holding temperatures (138-160).
5, the above-mentioned wood pulp slurry that obtains through boiling is delivered to extruding from the batch turning pond and washed material extraction yellow liquor, washing is to residual alkali≤100g/m3; Utilize desander to carry out centrifugal removal of impurities, starch the dense 0.4-0.8% of being controlled to be, advance to starch pressure 0.28-0.31Mpa.
6, adopt chlorination-alkali treatment-hypochlorite to bleach for three sections then, technical parameter is: chlorination is led to chlorine dose 0.6% (0.4-0.6), is transferred alkali number 80-100g/m
3, bleaching temperature≤50 ℃, bleaching chlorine dosage than the sodium hypochlorite bleaching agent that adds 0.3g/l (0.3-0.7), extraordinarily go into hypo dechlorination by 2.0 of residual chlorine dose in the slurry by slurry volume, are 1.5% to add hydrochloric acid and carry out acid treatment by the percentage by weight of slurry.
7, secondary washing is washed till slurry pH value 6-9
8, the wood pulp that obtains after the secondary washing is manufactured paper with pulp be the pulp of specification 600 * 800mm.
Embodiment 3: soda processes three
1, uses papermaking level needlebush pulpboard 6000Kg, through the paging device paging.
2, the NaOH with 12% (6-12) floods into the slurry congee that concentration is 4.0% (3-6).
3, with slurry congee pump it is sent into the squeezer extruding and discongests loosen collagen fibre.
4, the wood pulp after will squeezing drops in the boiling vessel and carries out boiling, and process conditions are: (1) digestant: NaOH, the total alkali concn 60g/l of cooking liquor, liquor ratio 1: 2.5 (2.5-3.5); (2) cooking liquor initial temperature 〉=40 ℃; (3) heated up in advance 10-15 minute, to 105 ± 5 ℃; (4) stop behind the vapour dry run again 25~30 minutes; (5) adopt 4 heating curves of 3 little steam bleedings, heat up 2 hours total times; (6) holding temperature is 170 ± 2 ℃.
5, the above-mentioned wood pulp slurry that obtains through boiling is delivered to extruding from the batch turning pond and washed material extraction yellow liquor, washing is to residual alkali≤100g/m3; Utilize desander to carry out centrifugal removal of impurities, starch the dense 0.4-0.8% of being controlled to be, advance to starch pressure 0.28-0.31Mpa.
6, adopt chlorination-alkali treatment-hypochlorite to bleach for three sections then, technical parameter is: chlorination is led to chlorine dose 0.4% (0.4-0.6), is transferred alkali number 80-100g/m
3, bleaching temperature≤50 ℃, bleaching chlorine dosage than the sodium hypochlorite bleaching agent that adds 0.7g/l (0.3-0.7), extraordinarily go into hypo dechlorination by 2.0 of residual chlorine dose in the slurry by slurry volume, are 1.5% to add hydrochloric acid and carry out acid treatment by the percentage by weight of slurry.
7, secondary washing is washed till slurry pH value 6-9
8, the wood pulp that obtains after the secondary washing is manufactured paper with pulp be the pulp of specification 600 * 800mm.
Embodiment 4: sulphite process one
1, uses papermaking level needlebush pulpboard 6000Kg, through the paging device paging.
2, the NaOH with 14% (10-16) floods into the slurry congee that concentration is 4.0% (3.5-5.5).
3, with slurry congee pump it is sent into the squeezer extruding and discongests loosen collagen fibre.
4, the wood pulp after will squeezing drops in the boiling vessel and carries out boiling, and process conditions are: (1) digestant: Na
2SO
3+ NaOH, cooking liquor total acid content 8% (5-9), liquor ratio 1: 4.0 (2.5-4.0); (2) cooking liquor initial temperature 〉=40 ℃; (3) heated up in advance 10-15 minute, to 105 ± 5 ℃; (4) stop behind the vapour dry run again 25~30 minutes; (5) adopt 3 heating curves of 2 little steam bleedings, heat up 2 hours total times; (6) 160 ± 2 ℃ of holding temperatures (150-172).
5, the above-mentioned wood pulp slurry that obtains through boiling is delivered to extruding from the batch turning pond and washed material extraction yellow liquor, washing is to residual alkali≤100g/m3; Utilize desander to carry out centrifugal removal of impurities, starch and densely be controlled to be 0.8%, advance to starch pressure 0.30-0.32Mpa.
6, adopt chlorination-alkali treatment-hypochlorite to bleach for three sections then, technical parameter is: chlorination is led to chlorine dose 0.3% (0.3-0.7), is transferred alkali number 80-100g/m
3, bleaching temperature≤50 ℃, bleaching chlorine dosage than the sodium hypochlorite bleaching agent that adds 0.7g/l (0.4-0.8), extraordinarily go into hypo dechlorination by 2.0 of residual chlorine dose in the slurry by slurry volume, are 2.0% to add hydrochloric acid and carry out acid treatment by the percentage by weight of slurry.
7, secondary washing is washed till slurry pH value 6-9
8, the wood pulp that obtains after the secondary washing is manufactured paper with pulp be the pulp of specification 600 * 800mm.
Embodiment 5: sulphite process two
1, uses papermaking level needlebush pulpboard 6000Kg, through the paging device paging.
2, flood into the slurry congee that concentration is 4.5% (3.5-5.5) with 6% NaOH.
3, with slurry congee pump it is sent into the squeezer extruding and discongests loosen collagen fibre.
4, the wood pulp after will squeezing drops in the boiling vessel and carries out boiling, and process conditions are: (1) digestant: Na
2SO
3+ NaOH, cooking liquor total acid content 9% (5-9), liquor ratio 1: 4.0 (1: 2.5-4.0); (2) cooking liquor initial temperature 〉=40 ℃; (3) heated up in advance 10-15 minute, to 105 ± 5 ℃; (4) stop behind the vapour dry run again 25~30 minutes; (5) adopt 3 heating curves of 2 little steam bleedings, heat up 2 hours total times; (6) holding temperature is 135 ℃.
5, the above-mentioned wood pulp slurry that obtains through boiling is delivered to extruding from the batch turning pond and washed material extraction yellow liquor, washing is to residual alkali≤100g/m3; Utilize desander to carry out centrifugal removal of impurities, starch and densely be controlled to be 0.8%, advance to starch pressure 0.30-0.32Mpa.
6, adopt chlorination-alkali treatment-hypochlorite to bleach for three sections then, technical parameter is: chlorination is led to chlorine dose 0.5% (0.3-0.7), is transferred alkali number 80-100g/m
3, bleaching temperature≤50 ℃, bleaching chlorine dosage than the sodium hypochlorite bleaching agent that adds 0.5g/l (0.4-0.8), extraordinarily go into hypo dechlorination by 2.0 of residual chlorine dose in the slurry by slurry volume, are 2.0% to add hydrochloric acid and carry out acid treatment by the percentage by weight of slurry.
7, secondary washing is washed till slurry pH value 6-9
8, the wood pulp that obtains after the secondary washing is manufactured paper with pulp be the pulp of specification 600 * 800mm.
Embodiment 6: sulphite process three
1, uses papermaking level needlebush pulpboard 6000Kg, through the paging device paging.
2, flood into the slurry congee that concentration is 5.0% (3.5-5.5) with 16% NaOH.
3, with slurry congee pump it is sent into the squeezer extruding and discongests loosen collagen fibre.
4, the wood pulp after will squeezing drops in the boiling vessel and carries out boiling, and process conditions are: (1) digestant: Na
2SO
3+ NaOH, cooking liquor total acid content 5% (5-9), liquor ratio 1: 4.0 (2.5-4.0); (2) cooking liquor initial temperature 〉=40 ℃; (3) heated up in advance 10-15 minute, to 105 ± 5 ℃; (4) stop behind the vapour dry run again 25~30 minutes; (5) adopt 3 heating curves of 2 little steam bleedings, heat up 2 hours total times; (6) holding temperature is 170 ± 2 ℃.
5, the above-mentioned wood pulp slurry that obtains through boiling is delivered to extruding from the batch turning pond and washed material extraction yellow liquor, washing is to residual alkali≤100g/m3; Utilize desander to carry out centrifugal removal of impurities, starch and densely be controlled to be 0.8%, advance to starch pressure 0.30-0.32Mpa.
6, adopt chlorination-alkali treatment-hypochlorite to bleach for three sections then, technical parameter is: chlorination is led to chlorine dose 0.7% (0.3-0.7), is transferred alkali number 80-100g/m
3, bleaching temperature≤50 ℃, bleaching chlorine dosage than the sodium hypochlorite bleaching agent that adds 0.4g/l (0.4-0.8), extraordinarily go into hypo dechlorination by 2.0 of residual chlorine dose in the slurry by slurry volume, are 2.0% to add hydrochloric acid and carry out acid treatment by the percentage by weight of slurry.
7, secondary washing is washed till slurry pH value 6-9
8, the wood pulp that obtains after the secondary washing is manufactured paper with pulp be the pulp of specification 600 * 800mm.
Embodiment 7: sulfate process one
1, uses papermaking level needlebush pulpboard 6000Kg, through the paging device paging.
2, flooding into concentration with 11% NaOH is 3.5% slurry congee.
3, with slurry congee pump it is sent into the squeezer extruding and discongests loosen collagen fibre.
4, the wood pulp after will squeezing drops in the boiling vessel and carries out boiling, and process conditions are: (1) digestant: NaOH+Na
2S, the total alkali concn 90g/l of cooking liquor, liquor ratio 1: 3; (2) cooking liquor initial temperature 〉=40 ℃; (3) heated up in advance 10-15 minute, to 105 ± 5 ℃; (4) stop behind the vapour dry run again 25~30 minutes; (5) adopt 4 heating curves of 3 little steam bleedings, heat up 2 hours total times; (6) holding temperature is 150 ± 2 ℃.
5, the above-mentioned wood pulp slurry that obtains through boiling is delivered to extruding from the batch turning pond and washed material extraction yellow liquor, washing is to residual alkali≤100g/m3; Utilize desander to carry out centrifugal removal of impurities, starch the dense 0.4-0.8% of being controlled to be, advance to starch pressure 0.28-0.31Mpa.
6, adopt chlorination-alkali treatment-hypochlorite to bleach for three sections then, technical parameter is: chlorination is led to chlorine dose 0.4%, is transferred alkali number 80-100g/m
3, bleaching temperature≤50 ℃, bleaching chlorine dosage than the sodium hypochlorite bleaching agent that adds 0.6g/l, extraordinarily go into hypo dechlorination by 2.0 of residual chlorine dose in the slurry by slurry volume, are 1.5% to add hydrochloric acid and carry out acid treatment by the percentage by weight of slurry.
7, secondary washing is washed till slurry pH value 6-9
8, the wood pulp that obtains after the secondary washing is manufactured paper with pulp be the pulp of specification 600 * 800mm.
Embodiment 8: sulfate process two
1, uses papermaking level needlebush pulpboard 6000Kg, through the paging device paging.
2, flooding into concentration with 9% NaOH is 4.5% slurry congee.
3, with slurry congee pump it is sent into the squeezer extruding and discongests loosen collagen fibre.
4, the wood pulp after will squeezing drops in the boiling vessel and carries out boiling, and process conditions are: (1) digestant: NaOH+Na
2S, the total alkali concn 120g/l of cooking liquor, liquor ratio 1: 3; (2) cooking liquor initial temperature 〉=40 ℃; (3) heated up in advance 10-15 minute, to 105 ± 5 ℃; (4) stop behind the vapour dry run again 25~30 minutes; (5) adopt 3 heating curves of 2 little steam bleedings, heat up 2 hours total times; (6) holding temperature is 135 ℃.
5, the above-mentioned wood pulp slurry that obtains through boiling is delivered to extruding from the batch turning pond and washed material extraction yellow liquor, washing is to residual alkali≤100g/m3; Utilize desander to carry out centrifugal removal of impurities, starch the dense 0.4-0.8% of being controlled to be, advance to starch pressure 0.28-0.31Mpa.
6, adopt chlorination-alkali treatment-hypochlorite to bleach for three sections then, technical parameter is: chlorination is led to chlorine dose 0.5%, is transferred alkali number 80-100g/m
3, bleaching temperature≤50 ℃, bleaching chlorine dosage than the sodium hypochlorite bleaching agent that adds 0.5g/l, extraordinarily go into hypo dechlorination by 2.0 of residual chlorine dose in the slurry by slurry volume, are 1.5% to add hydrochloric acid and carry out acid treatment by the percentage by weight of slurry.
7, secondary washing is washed till slurry pH value 6-9
8, the wood pulp that obtains after the secondary washing is manufactured paper with pulp be the pulp of specification 600 * 800mm.
Embodiment 9: sulfate process three
1, uses papermaking level needlebush pulpboard 6000Kg, through the paging device paging.
2, flooding into concentration with 18% NaOH is 5.5% slurry congee.
3, with slurry congee pump it is sent into the squeezer extruding and discongests loosen collagen fibre.
4, the wood pulp after will squeezing drops in the boiling vessel and carries out boiling, and process conditions are: (1) digestant: NaOH+Na
2S, the total alkali concn 40g/l of cooking liquor, liquor ratio 1: 3; (2) cooking liquor initial temperature 〉=40 ℃; (3) heated up in advance 10-15 minute, to 105 ± 5 ℃; (4) stop behind the vapour dry run again 25~30 minutes; (5) adopt 2 heating curves of 1 little steam bleeding, heat up 2 hours total times; (6) holding temperature is 170 ± 2 ℃.
5, the above-mentioned wood pulp slurry that obtains through boiling is delivered to extruding from the batch turning pond and washed material extraction yellow liquor, washing is to residual alkali≤100g/m3; Utilize desander to carry out centrifugal removal of impurities, starch the dense 0.4-0.8% of being controlled to be, advance to starch pressure 0.28-0.31Mpa.
6, adopt chlorination-alkali treatment-hypochlorite to bleach for three sections then, technical parameter is: chlorination is led to chlorine dose 0.6%, is transferred alkali number 80-100g/m
3, bleaching temperature≤50 ℃, bleaching chlorine dosage than the sodium hypochlorite bleaching agent that adds 0.3g/l, extraordinarily go into hypo dechlorination by 2.0 of residual chlorine dose in the slurry by slurry volume, are 1.5% to add hydrochloric acid and carry out acid treatment by the percentage by weight of slurry.
7, secondary washing is washed till slurry pH value 6-9
8, the wood pulp that obtains after the secondary washing is manufactured paper with pulp be the pulp of specification 600 * 800mm.
Embodiment 10:
Can add the M-101 auxiliary agent in the foregoing description digestion process, addition is 0.15-0.25%.