469 results about "Chemical pulp" patented technology

A method for treatment of chemical pulp for the manufacturing of microfibrillated cellulose includes the following steps: a) providing a hemicellulose containing pulp, b) refining the pulp in at least one step and treating the pulp with one or more wood degrading enzymes at a relatively low enzyme dosage, and c) homogenizing the pulp thus providing the microfibrillated cellulose. According to a second aspect of the invention a microfibrillated cellulose obtainable by the method according to the first aspect is provided. According to a third aspect of the invention, use of the microfibrillated cellulose according to the second aspect in food products, paper products, composite materials, coatings or in rheology modifiers (e.g. drilling muds) is provided.

The present invention discloses methods of bleaching chemical pulp that combine xylanase enzymes with hydrogen peroxide, peracids, or a mixture. The method comprises the steps of carrying out a chemical pulping operation, optionally followed by delignifying the pulp with oxygen, then combining xylanase enzymes with hydrogen peroxide, peracids, or a mixture to bleach the pulp. The method allows the mill to use both xylanase and peracids in a single bleaching tower to decrease the usage of chlorine dioxide and other bleaching chemicals. The pulp bleaching method of the present invention may be performed in a pulp mill as part of a complex pulp bleaching process.

The invention relates to an oxygen delignification processing method of grass unbleached chemical pulp. The oxygen delignification of the pulp is processed after cooking and before bleaching. Its rigidity before the oxygen delignification is potassium permanganate value 16-28 (equals to karber value 26-50). After pumping into the oxygen delignification reaction tower and inflating sodium hydroxide, magnesium salt and oxygen, the chemical pulp happen the oxygen delignification in the reaction tower. The chemical pulp with rigidity of potassium permanganate value 10-14 (equals to karber value 14-18) is achieved after the oxygen delignification. The invention can remove the lignin in the pulp effectively and the removal rate is 86-98%. It reduces the degradation of the cellulose to simplify the bleaching process and cut down the dosage of the chemicals. The bleached pulp has good rigidity and drainability. The breaking length of the pulp can reach 4500-8000m and its fold-resistant times can reach 20-70.

A method for the determination of cellulosic-fibre properties, such as, but not limited to, residual lignin content of chemical pulp, with the aid of a spectroscopic technique obtained over a range covering the visible and the near-infrared regions of the electromagnetic spectrum, comprising the steps of obtaining a sample from the process line, minimally removing some excess water, exposing the fibres in the sample to a large beam light source, optionally moving the sample at a constant speed, and acquiring the spectral data over a pre-determined length of time, and correlating the spectrum to a previously determined calibration so as to determine the Kappa number. Alternatively, as an arrangement for process control, along with other varying configurations, the instant invention includes the mounting of the excitation light source and fibre-optic probe along the various locations of the kraft cooking and bleaching process, such as 1) at the drum brownstock washers and 2) throughout the bleach plant deckers, located just before the doctored blade, the probe being connected to a fast scanning spectrometer, via fibre optic cables, with a computer sequencing spectral acquisition and correlating the spectrum against a predetermined calibration, and logging the results. The process configuration, with the use of the instant invention, overcomes all limitations of prior art, including sampling hardware and sample preparation, and provides true online Kappa number determinations of the order of seconds, as compared to current state of the art Kappa analyzers which require 10 to 15 minutes per analysis. The present method is capable of measuring residual lignin content of chemical pulps with varying consistency, accounts for species effects to provide species insensitivity and can provide analysis in less than 10 seconds. The method can provide true online continuous measurement of Kappa number for feedforward and feedback control of the bleaching, paper machine and kraft cooking processes.

The present invention discloses a bleached chemical pulp prepared by using graminoid plant as raw material and its preparation method. Said invention is characterized by that it utilizes a high-hardness pulp which is obtained by using cooking process and whose permanganate number is 16-28 and equal to Kappa number 26-50 and makes said high-hardness pulp undergo the processes of pulp-washing and bleaching treatment so as to obtain the invented bleached chemical pulp whose breaking length is 4500-8000 m and folding endurance is 20-70 times.

The invention is directed to a method for separating xylose from lignocelluloses rich in xylan, particularly wood, and for obtaining pulp, characterized by the following steps: (1) pretreating wood chips through mechanical destruction of the original structure; (2) impregnating the obtained wood mass with diluted mineral acid; (3) carrying out prehydrolysis of the obtained wood mass modified by the process under the influence of steam at an elevated temperature to hydrolyze the obtained hemicelluloses; and (4) removing the hemicelluloses from the residual pulp by washing, filtering and/or centrifuging while obtaining an aqueous solution rich in xylose. The combination of method steps according to the invention makes it possible to achieve high α-cellulose contents with very low proportions of xylose, that is, highly pure chemical pulp qualities, while at the same time enabling a virtually quantitative separation of the valuable xylose.

In the conventional process of producing a coated paper, the use of a furnish that is characterized by a base sheet fiber content made of about 60 to 85 weight percent of a bleached thermomechanical pulp (TMP), about 10 to 35 weight percent of a bleached chemical pulp and 0 to about 15 weight percent of a deinked pulp, and also comprising about 12 to 20 weight percent of an inorganic filler, with a freeness below 50 ml Csf and a brightness over 75° ISO, gives a coated paper of the same or superior quality and at a much lower cost than the usual coated paper obtained through a conventional process.

The invention discloses an alkaline pectinase production method and application in papermaking pulping. The alkaline pectinase production method comprises the steps of: selective breeding of a bacterial strain, culturing of the bacterial strain, fermentation through shaking a flask, and preparation of an enzyme liquid. The method is characterized in that the bacterial strain subjected to the selective breeding is achieved through separated screening of a naturally acquired bacterial sample and mutagenesis of the bacterial strain at cellular level, i.e. heat-resistant Bacillussubtillis with a laboratory number of MAPLE61 and preservation number of CCTCC NO:M2010004; and when the heat-resistant Bacillussubtillis is used for papermaking pulping, raw materials are soaked with an alkaline pectinase solution after the pickling treatment. When the invention is used for papermaking pulping, the prepared chemical pulp has favorable strength property and bleaching property; and after simple oxidation chlorine bleaching, the whiteness of the pump can reach 80-90 percent, breaking length can reach 6000-7000m, and meanwhile, alkali consumption is reduced about 20-40 percent and the production cost is reduced about 20 percent.

A cardboard with great rigidity and low grammage, as well as a package made thereof, is described. The cardboard consists of a core, which is surrounded by at least one, preferably 1-3 outer plies, on each side. The cardboard has a grammage of 100-300 g/m2, a bending resistance index of at least 25 Nm6/kg3, and a Scott Bond z-strength of at least 100 J/m2. The core of the cardboard consists of chemi-thermomechanical pulp and has a density of 200-450 kg/m3 and the core constitutes 55-80% of the total grammage of the cardboard. The outer plies have a tensile stiffness index of 7.0-9.5 kgNm/g and mainly consist of chemical pulp.

The invention relates to the field of papermaking and discloses a preparation method of hydrophobic oilproof paper. The preparation method includes: 1), making body paper: soaking bleached softwood chemical pulp, and pulping; mixing the bleached softwood chemical pulp, carboxymethyl cellulose, bacterial cellulose and dissolving pulp, making handsheet, and drying to obtain the body paper; 2), dissolving a natural polyhydroxy high molecular material in water, stirring, heating, holding temperature until a system is transparent, stirring, cooling to room temperature to obtain coating liquid, andcoating; 3), drying the body paper after being precoated, using an acyl chloride solution to treat the surface of the body paper, and drying to obtain a finished product. The problem that paper is porous is solved by means of coating the surface of the paper with the polyhydroxy high molecular material which is natural and easy to degrade, and an acyl chloride compound not containing fluorine is used to replace fluorine-containing polymer to endow the paper with hydrophobicity and oilproofness, so that environment friendliness is realized. In addition, paper prepared by the method has good strength performance and printability.

The invention provides a washing process in the grass pulping. It contains the following steps: A) send the cooked pulp into the presser for pressing to get the coarse pulp. B) Process the coarse pulp through the jumping screen. C) Send the screened pulp into the pulp washer for washing. The rigidity of the screened pulp is potassium permanganate value 16-28 (equals to karber value 24-50). The washed solvent remains 90-150ppm. Take the high rigidity pulp in this invention as materials to prepare bleaching chemical pulp by pressing and washing. The whiteness of the chemical pulp is 68-82%ISO and the removal rate of the lignin is 84-98%. The quality of the bleaching chemical pulp prepared by the grass is similar, even better than that of the exciting hardwood pulp.

The invention discloses a method that uses esterase obtained by 100 percent deinking and desizing of wasted newspaper controls sticky which mainly aims at producing the low fixed amount newspaper by using the 100 percent deinking and desizing of the wasted newspaper, adopts Optimyze 525 esterase control sticky and produces the newspaper with 45g/mm<2> fixed amount. The invention has the advantages of reducing the dosage of the sticky in the paper pulp, leading the sticky removing rate to be about 20 percent to 40 percent, reinforcing the operating performance of a paper machine, and helping to improve the speed and the output of the paper machine; by adopting deinking and desizing of 100 percent wasted newspaper to make 45g/m<2> lowing amount offset newsprint, the obtained products have good quality, chemical pulp and groundwood pulp which are high in pollution and high consumption are eliminated, the manufactory cost of the pulp material and the processing cost of the water are reduced, and the discharged waste water and the pollutants are reduced.

This invention discovers a special pigment groom hectograph paper and its preparation. It utilizes the advantages of high yields machine pulp (PRC-APMP) and deink pulp (DIP) which is well thickness and green environment. That is optimizing pigment spreading formulation, optimizing pulp to materials ratio and its wet end chemical and copy making technique to reach the white value of all bleaching chemical pulp proportioning copy paper. The advantages of the products are: better printing adaptability, better relaxation thickness, better printing effect features compared with all chemical pulp hectograph paper. It's capable of producing top grade office and printing culture special pigment groom hectograph paper which is made according to different clients' requirement and selecting different optimized features' technique for different application such as laser printing, xerography and hectograph etc. So, it's capable of decreasing all chemical pulp quantity, saving wood, protecting forest, protecting environment from pollution.

The invention relates to a supporting method of a roadway in a coal mime, particularly to a supporting method of a permeable soft broken rock stratum roadway. The supporting method aims at solving the problems that soft broken rock stratum roadways especially permeable soft broken rock stratum roadways are poor in supporting effect, high in cost and the like. The supporting method comprises the steps of first concrete spraying; combined support through high strength deformed steel bar anchor rods and diamond metal nets; anchor cable installation; secondary concrete spraying; installation of chemical pulp grouting anchor rods; installation of cement slurry grouting anchor rods.

The invention discloses an oil-tea camellia fruit shell semi-chemical pulp preparing process, comprising main steps of preprocessing, boiling, black liquid extracting, washing, mechanical pulp grinding, abeyance eliminating, purifying and screening. Oil-tea camellia fruit shell waste with rich resources is used as a new pulping raw material to produce semi-chemical pulp, so the comprehensive use problem of the oil-tea camellia fruit shell waste is effectively solved, the condition of fiber resource shortage in the paper making industry is relieved, the wood resource consumption in pulping and papermaking is reduced, and the natural environment is protected; the oil-tea camellia fruit shell semi-chemical pulp preparing process overcomes the negative influence of chemical composition of oil-tea camellia fruit shells to the pulping performances, a semi-chemical pulping method massively retaining lignin and hemicellulose is adopted, and the prepared oil-tea camellia fruit shell semi-chemical pulp is less in chemical medicine consumption, high in paper pulp yield, good in strength and low in cost. The oil-tea camellia fruit shell semi-chemical pulp preparing process is strong in operability, low in production cost and easy for realizing large-scale production.

Mechanical or Chemical pulp is treated with about 0.01 weight % to about 5 weight % of a Mixture. The Mixture is water; diethylenetriaminepentakis(methyl)phosphonic acid or its known salts; polyacrylic acid or its known salts; and optionally one or more inert compounds. This Mixture acts to either maintain the brightness level of the pulp at the target level or to increase the brightness level of the pulp. In addition the Mixture allows for maintaining the pulp at the target level of brightness even when the amounts of other ingredients, such as hydrogen peroxide, hydrosulfite, sodium silicate and magnesium, that are typically added to the pulp, are reduced.

The invention discloses a method for preparing oligosaccharide and paper pulp, belonging to the technical fields of pulping and the comprehensive utilization of pulping. The method comprises the steps of: using crop straws as raw materials, pre-treating the raw materials to obtain a pre-extracting solution, concentrating the pre-extracting solution by a membrane separation method, then obtaining a crude xylan solution via precipitation and centrifugal separation, and then preparing oligosaccharide via enzymolysis, vacuum concentration and frozen-drying. The pre-treated solid residues are stewed via an alkaline process so as to prepare unbleached paper pulps of which the indexes such as fiber length, whiteness, fracture length, tear resistance, folding strength and the like are all improved. The generated black liquid has the characters of low viscosity and high heat productivity. The method for preparing oligosaccharide and paper pulp integrates the comprehensive utilization method with the biomass transformation method on the premise of optimizing the traditional alkaline chemical pulping technique to prepare products with high additional values, namely oligosaccharide, thereby increasing the quality of the paper pulp and the extraction, vaporization and combustion performances of the black liquid.

The invention discloses a paper making craft which replaces the chemical pulp making with biological fermentation pulp making, comprising process sections of pulp making and paper making. The procedures can be described as follows: (1) material preparation: fiber plants are grinded; (2) dissociation of the fiber: the grinded fiber plants are sterilized through steaming and boiling; after being cooled, mould that can decompose cellulose and lignin is added in; then the mixture is evenly stirred and put into a fermentation tank to be fermented; when the fiber plants are dissociated fluffy, the paper pulp is made. Since a plurality of chemical treating procedures are avoided due to the spare of chemical source materials, more than twenty procedures in previous paper making process are reduced into only several procedures, therefore, the paper making procedures are greatly simplified and a large amount of producing materials and energy is saved; thus the paper making craft has the advantages of greatly reduced production cost, source-saving and energy-saving effects.

The invention discloses a method for preparing pulp by gramineous straw. The method sequentially comprises the following steps: (1) pre-treating the gramineous straw as a raw material; (2) physically pulping to obtain a straw fiber reinforced polymer (FRP); (3) adding water to the straw FRP obtained in step (2), thread-rolling and grinding until length of the straw FRP is 10-20mm to obtain fiber pulp; (4) decoloring or coloring the fiber pulp; and (5) mixing the fiber pulp treated in step (4) with the conventional chemical pulp or waste pulp based on the dry weight ratio of 1:0.1-10, then adding water for diluting the obtained mixed pulp, and finally obtaining the mixed pulp raw material. The invention further discloses use of the obtained pulp in preparation of the pulp molding product. The pulp obtained by the method takes the waste crop-the gramineous straw as the raw material and has the characteristics of low raw material cost, wide use, good industrial application prospect and the like.

The invention discloses a method for applying peanut shells to synchronously prepare nanocellulose crystal and sugar. The method uses the peanut shells as a raw material to extract cellulose, adopts an enzymatic hydrolysis method to prepare the nanocellulose crystal, controls the enzymolysis degree and obtains sugar liquor at the same time, belonging to the technical field of nanostructure materials. The nanocellulose crystal preparation method does not adopt an inorganic acid hydrolysis method generating a lot of waste acid and impurities but adopts the cellulose enzymatic hydrolysis method with mild process conditions and strong specificity, being green and environmentally-friendly and conforming to the national strategy of sustainable development requirements. The method uses the peanut shells as the raw material to replace high-cost raw materials such as cotton, chemical pulp or microcrystalline cellulose and the like, so that the comprehensive utilization value of the peanut shells is increase, the current situations of waste of resources and economic losses as most of the agricultural and sideline products are used as wastes or fuels are changed, and the economic and social benefits are brought while the environment is improved. A lot of sugar liquor is produced during preparation, and the purpose of making the most of things is achieved.

The production process of bleached chemical pulp with hemp stalk core includes the following steps: 1. cutting hemp stalk core as material into 2-3 cm long sections, sieving and digesting in sulfate process to produce pulp; 2. washing and sieving the obtained pulp and oxygen delignifying; and 3. bleaching pulp with small amount of hypochlorite in a short program. Of the process, the medium concentration oxygen delignifying technology is one clean environment friendly bleaching technology with the bleached effluent being recovered and reused completely without environmental pollution, and the medium concentration hypochlorite bleaching can lower the exhausted waste water and reduce chemical and power consumption effectively. The pulp of the present invention can meet the requirement of making common paper.

The present invention aims to further advance the acid treatment or irradiation technology for pulp to develop a bleaching process using smaller amounts of chlorine chemicals with higher efficiency as compared with conventional bleaching processes. It also aims to provide an excellent high brightness pulp having a low environmental impact and no discoloration as well as a paper containing it. The present invention provides a chlorine-free bleaching process with very high efficiency by irradiating a pulp washed after an acid treatment with UV light and/or visible light at a wavelength of 100-400 nm under alkaline conditions, preferably in a pH range of 10-13. The acid treatment can be performed under conditions of pH 1-6 and a temperature of 80° C. or more. The irradiation treatment can be performed in the presence of at least one compound selected from the group consisting of reducing agents, peroxides, and hydrogen-donating organic compounds. The present invention also provides a high brightness chemical pulp having an ISO brightness of 88% or more and a brightness loss of 1.0% or less in a specific fading test.