40 results about "Dissolving pulp" patented technology

The invention discloses a method for preparing high-quality dissolving pulp from low-grade plant fiber raw materials, and belongs to the technical field of biomass pulping. The preparation method comprises the following steps: screening a low-grade plant fiber raw material to obtain a fiber raw material of which the length is 20-30 mm, the width is 10-15 mm and the thickness is 3-5 mm; carrying out deep prehydrolysis-sulfate cooking treatment on the screened fiber raw materials to obtain unbleached sulfate pulp fibers; performing deep eutectic solvent and elemental chlorine-free bleaching treatment on the unbleached sulfate pulp fiber to obtain paper pulp fiber with low kappa number; and carrying out biological enzyme treatment on the paper pulp fibers with low kappa number to obtain the high-quality dissolving pulp. According to the method, the morphology and the structure of chemical pulp fibers are effectively regulated and controlled by designing deep eutectic solvent treatment, and deep dissolution of residual hemicelluloses and lignin is achieved; through biological enzyme treatment, the alpha-cellulose content and the Fock reaction performance are further improved, and finally the high-quality dissolving pulp is prepared.

The invention discloses a bamboo pulp lyocell fiber production method, which comprises: (1) preparing a bamboo dissolving pulp, loading bamboo chips into a pot, preheating, raising the temperature in the pot to 110-130 DEG C, introducing medium-pressure steam, rapidly raising the temperature in the pot to 160-170 DEG C, injecting a pre-hydrolysis liquid formed by mixing hot water and an acidic catalytic auxiliary agent from the bottom of the pot, and carrying out thermal insulation at a temperature of 165-175 DEG C for 30-120 min; and (2) dissolving NMMO, namely mixing the dissolving pulp prepared in the step (1) with an NMMO aqueous solution, mechanically stirring and uniformly mixing for 10 minutes at 90 DEG C, then carrying out vacuum dehydration, gradually raising the temperature to 105 DEG C from 90 DEG C, starting timing when the temperature is raised to 105 DEG C, and dissolving for 40 minutes. According to the production method and the production equipment of the bamboo pulp lyocell fiber, the pentosan content can be effectively reduced, the reaction uniformity can be improved and the preparation requirements of the bamboo-based lyocell fiber can be met through the specific preparation method and the processes such as steam preheating and temperature rising combined with liquid-phase extraction and prehydrolysis.

The invention relates to a preparation method of dissolving pulp with uniform cellulose polymerization degree distribution, and belongs to the technical field of dissolving pulp. The preparation method of the dissolving pulp comprises the following steps: (1) raw material pulp pretreatment and grading screening; (2) cold alkali swelling and pulsed electric field cooperative treatment; (3) selective enzymolysis treatment of a compound enzyme system of cleavage enzyme and excision enzyme; and (4) neutralizing and washing the slurry. Compared with the prior art, the preparation method of the dissolving pulp provided by the invention has the advantages that the centralization of a polymerization degree main distribution interval (such as 800-1000) is realized, the standard deviation is obviously reduced, and the cellulose polymerization degree distribution is narrower and more controllable. No organic solvent or strong oxidant is needed in the whole preparation process of the dissolving pulp, the alkali liquor can be recycled, the enzyme preparation can be repeatedly used, and good environment friendliness is achieved.

The preparation method of the environment-friendly anti-aging packaging base paper comprises the following steps: taking softwood pulp and dissolving pulp, pulping for the first time, adding microcrystalline cellulose, and stirring to form first pulp; adjusting the pH value of the first slurry to be neutral, adding a water-soluble chitosan-polyphenol compound, and pulping for the second time to form second slurry; adding oxidized sodium alginate into the second pulp, and pulping for the third time to form third pulp; forming raw paper according to a papermaking process; the invention further provides packaging base paper which has the characteristic of good anti-aging performance. Softwood pulp and dissolving pulp are used as papermaking raw materials, microcrystalline cellulose, a water-soluble chitosan-polyphenol compound and oxidized sodium alginate are used, a pulping process which is sequentially added according to a sequence is formed, a stable fiber network is constructed layer by layer, and a mechanism of skeleton supporting, covalent crosslinking and antioxidant end capping is formed. The anti-aging performance of the raw paper is improved.

The application discloses a method for improving the quality of dissolving pulp based on microwave-assisted low eutectic solvent, and belongs to the technical field of papermaking industry. The method solves the technical problem of slow solvent mass transfer and reaction and low efficiency in the traditional heating method. The method for improving the quality of dissolving pulp based on microwave-assisted low eutectic solvent can realize the rapid viscosity reduction and reaction performance improvement of the dissolving pulp within 30-300 seconds, and overcomes the problems of slow mass transfer and reaction and low efficiency of the low eutectic solvent in the traditional heating method. The method has the characteristics of simple operation, instant high efficiency, green low carbon, low cost and recyclability.

The invention discloses a method for cleanly preparing dissolving pulp based on waste cotton textiles, and belongs to the technical field of textile recovery and green chemistry. The preparation method comprises the following steps: taking betaine as a hydrogen bond acceptor, taking organic acid as a hydrogen bond donor, and adding a certain proportion of deionized water to construct a hydrated ternary eutectic solvent system; the pretreated waste cotton fabric is placed in the ternary eutectic solvent system to be subjected to depolymerization treatment, the solvent can be recycled after being blended, then refining treatment is carried out, and finally the regenerated dissolving pulp is obtained. The obtained regenerated dissolving pulp has the following performance indexes: the polymerization degree is 500-700, the alpha cellulose content is more than or equal to 97%, the whiteness is more than or equal to 84%, the iron content is less than or equal to 20ppm, and the fiber length is 26-32%. The method is mild in process condition, simple and convenient to operate, low in energy consumption, recyclable in solvent and free of high-alkali waste liquid, conforms to the green chemistry principle, and provides an economic and environment-friendly effective way for high-valued resource utilization of the waste cotton textiles.

The application discloses a method for improving the reaction performance of dissolving pulp by using an acidic eutectic solvent, and belongs to the technical field of dissolving pulp preparation. The method solves the technical problems of high reaction condition requirement, poor environmental friendliness, high cost and poor synergy in improving the reaction performance of dissolving pulp. The method disclosed by the application uses the acidic eutectic solvent to make the fiber swell through hydrogen bond competition, to strengthen the mass transfer and reaction of the solvent, and the active protons dissociated can depolymerize the cellulose macromolecular chain and destroy the fiber structure. The swelling effect accelerates the depolymerization of the cellulose macromolecular chain and strengthens the morphological damage of the dissolving pulp. Through the comprehensive effect of fiber swelling, morphological damage and cellulose macromolecular chain depolymerization, the reaction effect is realized, the reaction efficiency is improved, and the method has the characteristics of simple operation, green and efficient, low cost, strong synergy and recyclable solvent.

The invention belongs to the technical field of xylooligosaccharide preparation, and discloses a method for co-producing dissolving pulp and xylooligosaccharide by using bagasse. Comprising the following steps: (1) mixing a hydrogen bond acceptor, an alkaline hydrogen bond donor and a protective agent, and heating and stirring to prepare an alkaline eutectic solvent; (2) adding the bagasse into an alkaline eutectic solvent, and heating and stirring for reaction to obtain a reaction mixture; (3) carrying out solid-liquid separation on the reaction mixture, washing a solid component to be neutral to obtain holocellulose, and collecting a washing solution; mixing the washing solution and the liquid component, adding into absolute ethyl alcohol, standing and precipitating, then carrying out solid-liquid separation, and washing and freeze-drying the solid precipitate to obtain hemicellulose; (4) respectively performing enzymolysis on holocellulose and hemicellulose by adopting xylanase, collecting enzymatic hydrolysate and enzymolysis residues, merging the enzymatic hydrolysate, and treating to obtain xylooligosaccharide; washing and freeze-drying holocellulose enzymolysis residues to obtain the dissolving pulp. The alkaline eutectic solvent is used for assisting enzymolysis to obtain the dissolving pulp and the xylooligosaccharide.

The application relates to a kind of acetylated grade dissolving pulp and its preparation method and application.It includes the following steps: S1 eutectic solvent is mixed with raw material dissolving pulp, heated reaction, and first dissolving pulp is obtained;The mass ratio of the raw material dissolving pulp and the eutectic solvent is 1:5-20;The eutectic solvent includes organic acid, metal salt and water;S2 removes part of the eutectic solvent in the first dissolving pulp, and second dissolving pulp is obtained;S3 water is diluted to the second dissolving pulp, and the mass concentration of cellulose is 2-5%, and third dissolving pulp is obtained;2) the pH of the third dissolving pulp is adjusted, cellulase is added, and enzyme treatment is carried out to obtain acetylated grade dissolving pulp.The technical problem to be solved is how to provide a kind of preparation method of acetylated grade dissolving pulp, without washing the dissolving pulp after early treatment, but with diluted eutectic solvent as the buffer solution of cellulase for enzyme treatment, so as to reduce production cost, improve production efficiency, and realize industrial production of product.

The invention belongs to the technical field of pulping, and particularly relates to a method for preparing dissolving pulp by using herb gold violet as a raw material. The preparation method comprises the following steps: crushing, screening, washing and filtering grass gold violet serving as a biomass raw material, entering a transfer bin, putting the grass gold violet into a reaction kettle, carrying out steam explosion twice and alkali liquor reaction, and after the reaction is finished, squeezing, pulping, bleaching, secondary squeezing, forming and drying to obtain the finished product dissolving pulp. The preparation method disclosed by the invention is high in environmental protection property, high in pulping yield and excellent in pulp quality, and provides a new direction for industrial pulping.

The invention particularly relates to a dissolving pulp production process which comprises the following steps: washing and soaking wood chips or cotton linters, and naturally draining to obtain a pretreated raw material; adding adjusting water into the pretreated raw material, then adding sodium sulfite, mixing and stirring, heating and preserving heat, and extracting pre-hydrolysis waste liquid to obtain semi-slurry; the ratio of the absolute dry mass of the pretreated raw materials to the volume of the adjusting water is 1: (5-8); in terms of SO2, the use amount of sodium sulfite is 2%-4% of the absolute dry mass of the pretreated raw material; the heating and heat preservation temperature ranges from 150 DEG C to 160 DEG C, and the heat preservation time ranges from 90 min to 120 min; carrying out sulfate cooking on the semi-slurry to prepare coarse slurry and cooking black liquor; the coarse pulp is bleached, pulped and sieved by adopting an OD0EOPD1 section sequence, and the dissolving pulp is prepared. According to the method, the quality of the dissolving pulp is remarkably improved by adopting sodium sulfite to prehydrolyze the dissolving pulp, the high-end application requirements of cellulose acetate, Lyocell fibers and the like can be met, the vacuum pulp washing link of semi-pulp after prehydrolysis is omitted, the pulp wastage rate is reduced, the MVR evaporator utilizes secondary steam compression reuse, and the water resource utilization rate is improved.

The invention provides water-resistant bobbin base paper and a process thereof, and the bobbin base paper comprises the following components in parts by weight: 80-120 parts of a natural wood fiber raw material, 3-9 parts of chitosan, 4-12 parts of a waterproof emulsion, 3-9 parts of a treating agent, 2-6 parts of a defoaming agent, 1-3 parts of a sterilizing agent and 2-4 parts of a cross-linking agent, the natural wood fiber raw material is one or a mixture of more of commercial paper pulp, waste paper and straw agricultural wastes; the commercial paper pulp is one or more mixed pulp of bleached softwood pulp, bleached hardwood pulp, dissolving pulp or unbleached paper pulp, the preparation process is simple, the prepared bobbin body paper has the advantages of high strength, water resistance and easiness in printing, meanwhile, the bobbin body paper also has excellent waterproof performance, and the service life of a bobbin paper product is prolonged.

The utility model discloses a blood thawing device, which belongs to the technical field of blood thawing and comprises a pulp dissolving instrument body, and a reciprocating swing type isolation placing mechanism is mounted at the upper end of the pulp dissolving instrument body; the reciprocating swing type isolation placing mechanism comprises a driving assembly and a swing assembly. A bearing plate is mounted on the swinging assembly; a containing groove is formed in the middle of the bearing plate. The bearing plate is further provided with a detachable water scraping mechanism. The detachable water scraping mechanism comprises a contact assembly and a movable assembly. The two movable assemblies are symmetrically distributed on the left side and the right side of the containing groove. The movable assembly is connected with the bearing plate; a contact assembly is installed on the movable assembly. Through the mode, the bearing plate continuously reciprocates back and forth, so that blood in the plasma bag continuously flows, the unfreezing efficiency can be improved, water can be disturbed through the isolation bag, and the situation that the unfreezing efficiency is reduced due to the fact that the temperature of the water near the isolation bag is not uniform is avoided.

The invention relates to the technical field of environment-friendly containers, and particularly discloses a plastic-free container meeting SUPD plastic-free requirements, the plastic-free container comprises a main body structure and an auxiliary structure, the main body structure and the auxiliary structure are both made of composite paperboards, and each composite paperboard comprises a base paper layer and a regenerated cellulose barrier layer arranged on the surface of the base paper layer; the regenerated cellulose barrier layer is a compact film formed by regenerating dissolving pulp cellulose fibers after being dissolved in a phenolic imidazole [C2mim] [Oh] ionic liquid (IL) and N, N-dimethylformamide (DMF) mixed solvent system, and the plastic-free container is free of any plastic component and conforms to the European SUPD plastic-free definition; the plastic-free container meeting the SUPD plastic-free requirement has the advantages that the environmental protection property comprehensively reaches the standard, the barrier property is excellent, the heat sealing forming is efficient and stable, the cost and process advantages are remarkable, and the like.

The invention discloses a production method and application of bamboo reed dissolving pulp. The production method of the dissolving pulp comprises the following steps: preparing materials, slicing bamboo reeds, tearing and softening, removing dust, cleaning and dehydrating; keeping the temperature at 150-175 DEG C for 90-150 minutes, and carrying out steam hydrolysis; a sulfite solution is adopted, cooking is conducted for 90-150 min at the temperature of 160-180 DEG C till the pH end point ranges from 5.5 to 6.5, and the hardness K of feed liquid ranges from 15 to 21; and then carrying out a coarse pulp washing and screening process, an oxygen delignification process and an A-DO-EOP-D1-D2 bleaching process so as to carry out multi-stage bleaching on the pulp. The bamboo reed is used as a raw material instead of wood, so that the wood is saved, the cost is reduced, the black liquor in the preparation process can be used as fulvic acid fertilizer, secondary solid waste pollution is avoided, and the method is environment-friendly and efficient in utilization. The dissolving pulp prepared by the method meets the standard and has antibacterial property when being applied to fiber materials.

The present application relates to a kind of weakly hydrophilic low back permeable non-woven fabric preparation method, mainly including the following sequentially performed steps: (1) preparation of hydrophobic modified viscose fiber: dissolved pulp with coniferous wood and broadleaf wood dissolved pulp is prepared viscose staple fiber;Again, through water-repellent finishing and other processes, obtain hydrophobic modified viscose fiber;(2) preparation of weakly hydrophilic low back permeable non-woven fabric: hydrophobic modified viscose fiber is sequentially subjected to opening, carding and water jet processing steps, then through hydrophilic finishing and drying, weakly hydrophilic low back permeable non-woven fabric is obtained.The present application solves the shortcomings that existing non-woven fabric is difficult to simultaneously meet the liquid rapid infiltration and low back permeation amount, by using the preferred water-repellent finishing liquid to hydrophobically modify the viscose fiber first, then using the preferred hydrophilic finishing liquid to hydrophilically modify, weakly hydrophilic low back permeable non-woven fabric is obtained, which has the characteristics of biodegradable, can make liquid rapid infiltration and low back permeation amount.

The invention belongs to the technical field of dissolving pulp preparation, and discloses a method for removing metal ions in dissolving pulp and the dissolving pulp. According to the invention, a specifically prepared organic acid pickling solution is adopted to carry out pickling complexing treatment on the slurry. After treatment, the removal effect of metal ions in the slurry is remarkable, and the following index requirements are met: the content of iron ions is less than or equal to 5mg / kg, the content of calcium ions is less than or equal to 30mg / kg, the content of magnesium ions is less than or equal to 20mg / kg, and the content of copper ions is less than or equal to 5mg / kg. The method particularly has an excellent removal effect on firmly combined iron ions, the highest removal rate reaches 89.9%, and the content of the iron ions is reduced from higher than 45 mg / kg to lower than 5 mg / kg, so that the high-purity slurry is obtained. The obtained slurry is beneficial to subsequent dissolution and spinning processes, and the pickling process has slight influence on the polymerization degree of the slurry and can be maintained within a reasonable range.

The application discloses a method for preparing high-quality bamboo dissolving pulp by pulp screening and eutectic solvent treatment, and belongs to the technical field of papermaking industry. The technical problems of the traditional method for preparing high-purity dissolving pulp, such as the high content of impurities in non-wood bamboo dissolving pulp, low purity and reaction performance of the pulp, strong resistance of fibers in heterogeneous reaction, uneven distribution of reaction reagents and uneven reaction are solved. Through the synergistic treatment of pulp screening and eutectic solvent, the purity and reaction performance of the dissolving pulp are simultaneously efficiently improved at a shorter reaction time and a lower treatment temperature. The screening of the pulp by the screening instrument with different mesh screens can remove the small component impurities which preferentially react, and the reaction of the long fiber fraction pulp and the reagent is strengthened, so that the problems of strong resistance of fibers in the traditional heterogeneous reaction, uneven distribution of reaction reagents, poor reaction uniformity and low reaction efficiency are overcome, and the purposes of reducing the reaction energy consumption and improving the quality of the dissolving pulp are achieved.

The invention relates to a chitosan quaternary ammonium salt lyocell fiber and a preparation method thereof. The preparation method comprises the following steps: 1) preparing raw materials, namely mixing needlebush dissolving pulp and hemp dissolving pulp to obtain mixed pulp; preparing an active chitosan quaternary ammonium salt into an aqueous solution, and adjusting the pH value to 8-10 to obtain a grafting solution; 2) activating and grafting the pulp: adding the mixed pulp into the grafting solution, and reacting at 60-80 DEG C for 3-24 hours to obtain activated pulp; 3) washing and drying to obtain modified pulp; and 4) dissolving and spinning: dissolving the modified pulp to prepare a spinning solution with the cellulose mass fraction of 8-15%, and carrying out dry-jet wet-spinning molding. The obtained modified lyocell fiber has the advantages of non-dissolution antibacterial property, supply chain safety improvement and consideration of mechanical property and hand feeling, the antibacterial requirement of a finished product use end is met, the bacterium growth risk of finished product storage and processing is reduced from the product, and the dual effects of production bacterium control and finished product bacterium resistance are achieved.

The invention relates to a manufacturing process of a premix in lyocell fiber production, which is used for manufacturing a lyocell fiber premix. The method comprises the following steps: adding a first additive into a first pulper to pre-treat cheap pulp so as to destroy the molecular structure of cellulose, so that the polymerization degree of the cheap pulp is reduced to 580-630 from more than 700 and is close to the index of dissolving pulp, then pressing water in pulp porridge to 48%-50% through a presser, crushing the pressed material through a crusher, feeding the crushed material into a pulp porridge storage tank, and storing the crushed material into a second pulper; then putting into a second pulper through a screw conveyor, uniformly mixing the treated cheap pulp and dissolving pulp in the second pulper, and adding an NMMO solvent, a second additive and a third additive to prepare a premix; according to the invention, a part of cheap slurry can be used to reduce the raw material cost, and the investment cost and the energy consumption can also be reduced.

The invention provides a method for refining bamboo wood dissolving pulp by an enzyme synergistic eutectic solvent. The method comprises the following steps: immersing bamboo powder in an enzyme preparation solution, and carrying out pretreatment, filtration, washing and drying to obtain a solid-phase material; and mixing the solid-phase material with the deep eutectic solvent, carrying out reaction and solid-liquid separation, and carrying out washing, chlorine-free bleaching and drying on the obtained solid to obtain the dissolving pulp. According to the brand new technical scheme, enzyme selective catalysis pretreatment and deep eutectic solvent treatment are organically coordinated, and high-yield, high-quality and clean preparation of the bamboo wood dissolving pulp is expected to be achieved under the mild condition. The core idea of the method is that the hemicellulose and lignin in the bamboo wood are precisely pre-degraded by utilizing high specificity and mildness of enzyme biological catalysis, so that the pulping effect of the subsequent eutectic solvent is coordinated and enhanced.

A process to manufacture dissolving pulp grade cellulose comprises providing a lignocellulosic material; providing a modified Caro's acid; exposing the lignocellulosic material to the modified Caro's acid for a period of time sufficient to allow the modified Caro's acid to delignify the lignocellulosic material and yield a solid cellulosic portion and a liquid portion with a high dissolved lignin content. Additional steps include separating the solid cellulosic portion from the liquid portion; exposing the solid cellulosic portion to a caustic solution yielding causticized solids; filtering the causticized solids; re-slurrying the causticized solids and neutralizing such to yield a dissolving pulp cellulose; and washing said dissolving pulp cellulose with water

The invention provides high-quality dissolving pulp and a preparation method thereof, and belongs to the technical field of dissolving pulp, the preparation method comprises the following steps: S1, loading wood flour into a spherical digester, adding a sodium hydroxide solution, controlling temperature and pressure, preserving heat and cooking to obtain coarse pulp; s2, deionized water is added into the crude pulp, the pH is adjusted, xylanase is added, then an activating auxiliary agent is added, activating treatment is conducted, pretreated pulp is obtained, and the activating auxiliary agent is a mixture of hydrosulfite and citric acid; s3, a chelating agent is added into the pretreated slurry, purified slurry is obtained, and the chelating agent is sodium tripolyphosphate cross-linked modified chitosan; and S4, carrying out bleaching treatment on the purified pulp by adopting chlorine dioxide, and obtaining the high-quality dissolving pulp after the bleaching is completed. According to the high-quality dissolving pulp prepared by the method, the alpha cellulose content can reach 94.2% or above, the iron content is 20 ppm or below, and the whiteness is 85% or above.

The utility model discloses a fish dissolved pulp fishy smell removal device which comprises a treatment box and a filter screen, a containing groove and a lead screw are arranged in the treatment box, a nut is rotatably connected to the outer portion of the lead screw and located in the containing groove, a hollow column is fixed to the outer portion of the nut, an insertion column is rotatably connected to the bottom of the filter screen, and the insertion column is located in the containing groove. According to the fishy smell removing device, when the inserting column is inserted into the hollow column, the bottom of the inserting column can pass through the special-shaped block and the clamping rod, the clamping rod can be deformed through the bottom of the inserting column, and the clamping rod can be inserted into the hollow column, so that the fishy smell can be removed, and the fishy smell can be removed. And then the bottom of the inserting column enters the containing area, the pressing force of the bottom of the inserting column on the clamping rod disappears after the bottom of the inserting column passes through the clamping rod, after the bottom of the inserting column enters the containing area, the clamping rod abuts against the clamping area of the inserting column due to the fact that the pressing force borne by the clamping rod disappears, and therefore the inserting column can be fixed into the hollow column.

The application discloses a preparation method of high-strength Lyocell regenerated cellulose fiber, and aims to solve the problem of insufficient mechanical strength of existing regenerated cellulose fiber caused by too wide molecular weight distribution of pulp. The method is characterized in that, through the synergistic effect of a mild pre-hydrolysis kraft (PHK) cooking process and an optimized multi-stage elemental chlorine-free (ECF) bleaching sequence (D0-E-D1), the lignin and hemicellulose are efficiently removed, and the long molecular chain of cellulose is maximally protected; through multi-stage gradient cold alkali extraction and purification treatment, the alkali concentration and low-temperature conditions are accurately controlled, and short-chain cellulose is selectively dissolved, so that the active regulation and narrowing of the molecular weight distribution of cellulose are realized, and a dissolving pulp with high polymerization degree and concentrated molecular weight distribution is obtained. Finally, the high-quality dissolving pulp is used to prepare Lyocell fiber with significantly enhanced mechanical properties through NMMO solvent system dry-jet wet spinning.

A process to manufacture dissolving pulp grade cellulose said process comprising the steps of: o providing a lignocellulosic material; o optionally, comminuting said lignocellulosic material into chips of a particle size no greater than 5 cm o providing a modified Caro's acid, wherein said modified Caro's acid o exposing said lignocellulosic material to said modified Caro's acid at a temperature of less than or equal to 45°C for a period of time sufficient to allow the modified Caro's acid to delignify said lignocellulosic material and yield a solid cellulosic portion and a liquid portion with a high dissolved lignin content; o separating said solid cellulosic portion from said liquid portion; wherein said solid cellulosic portion has the following characteristics: o lignin content below 1%; o hemicellulose content below 15%; and o cellulose content of at least 75%; - exposing said solid cellulosic portion to a caustic solution yielding causticized solids; - filtering said causticized solids; - re-slurrying said causticized solids and neutralizing such to yield a dissolving pulp cellulose; and - washing said dissolving pulp cellulose with water to remove the neutralized salts to obtain a high purity dissolving pulp cellulose having the following characteristics: o over 90% cellulose content; o less than 1% lignin content; o less than 5% hemicellulose content; and o an intrinsic viscosity ranging between 100 – 800 mL / g.

A process to manufacture dissolving pulp grade cellulose said process comprising the steps of: o providing a lignocellulosic material; o optionally, comminuting said lignocellulosic material into chips of a particle size no greater than 5 cm o providing a modified Caro's acid, wherein said modified Caro's acid o exposing said lignocellulosic material to said modified Caro's acid at a temperature of less than or equal to 45°C for a period of time sufficient to allow the modified Caro's acid to delignify said lignocellulosic material and yield a solid cellulosic portion and a liquid portion with a high dissolved lignin content; o separating said solid cellulosic portion from said liquid portion; wherein said solid cellulosic portion has the following characteristics: o lignin content below 1%; o hemicellulose content below 15%; and o cellulose content of at least 75%; - exposing said solid cellulosic portion to a caustic solution yielding causticized solids; - filtering said causticized solids; - re-slurrying said causticized solids and neutralizing such to yield a dissolving pulp cellulose; and - washing said dissolving pulp cellulose with water to remove the neutralized salts to obtain a high purity dissolving pulp cellulose having the following characteristics: o over 90% cellulose content; o less than 1% lignin content; o less than 5% hemicellulose content; and o an intrinsic viscosity ranging between 100 – 800 mL / g.

The invention provides a flame-retardant antibacterial skin-friendly functional lyocell fiber and a preparation method thereof, and belongs to the field of fiber materials.The flame-retardant antibacterial skin-friendly functional lyocell fiber is prepared by preparing microencapsulated melamine phosphate powder and an amino acid cross-linked phytic acid solution, infiltrating the microencapsulated melamine phosphate powder into the amino acid cross-linked phytic acid solution, curing, washing and drying, and the flame-retardant antibacterial skin-friendly functional lyocell fiber is obtained. Modified flame retardant powder is obtained; dissolving pulp in an NMMO aqueous solution, adding a stabilizer, a cross-linking agent and the modified flame retardant powder, and mixing and reacting to obtain a spinning solution; and performing ultrasonic treatment and oil bath on the spinning solution, and spinning to obtain the flame-retardant antibacterial skin-friendly functional lyocell fiber. The phytic acid and the microencapsulated melamine phosphate are utilized to modify the lyocell fibers through crosslinking and curing, efficient, durable, flame-retardant and antibacterial effects are achieved, the preparation process is simple, and the lyocell fibers can be widely applied to the fields of close-fitting household textile articles, medical textile articles and the like.

The utility model relates to a dismounting device for an automatic control valve of a dissolving pulp digester, and belongs to the technical field of maintenance tools. Comprising a circular plate; two through holes I are symmetrically formed in the circular plate; two semicircular plates are arranged below the circular plate; a through hole II is formed in the semicircular plate; fastening bolts penetrate through the first through holes and the second through holes. The fastening bolt is provided with a nut which is used for fixing the circular plate and the semicircular plate together; and the edge of the semicircular plate is step-shaped. The dismounting device for the automatic control valve of the dissolving pulp digester is special equipment for dismounting a tank opening, and solves the problem that the automatic control valve can only be dismounted by knocking in the prior art. In addition, the kettle type device can be applied to assembly and disassembly of other kettle type devices.

The invention relates to the technical field of dissolving pulp, in particular to a method for preparing dissolving pulp by screening and refining bleached bamboo pulp with an alkaline eutectic solvent. Comprising the following steps: (1) firstly, performing fiber screening on slurry through a Bauer-McNett fiber screening instrument; and (2) purifying the slurry by using an alkaline eutectic solvent choline hydroxide (ChOH)-urea (UR). According to the method, impurity cells in the pulp are removed through fiber grading, then the pulp is subjected to alkaline eutectic solvent refining to remove hemicellulose in the pulp, the content of alpha-cellulose in paper pulp is increased, and the dissolving pulp with high purity is obtained. The method is mild in reaction condition, time-saving, simple and convenient to operate, the used deep eutectic solvent (DES) can be repeatedly recycled, and the process of the method is environment-friendly and clean.