18results about "Mechanical/thermomechanical pulp" patented technology

There is provided a method of producing a paper- or linerboard having a grammage measured according to ISO 536:2019 of 170-310 g / m2 and comprising a print layer, a middle layer and a back layer, wherein the middle layer is formed from a middle layer furnish comprising at least 25% by dry weight CTMP and the back layer is formed from a back layer furnish comprising an unbleached pulp, such as an unbleached kraft pulp, said method comprising the step of subjecting a multi-layered web at a speed of at least 600 m / min to pressing in a press section comprising a first and a second double-felted shoe press nip arranged in series, wherein the total press impulse of the double-felted shoe press nips is at least 95 kPa*s, preferably at least 100 kPa*s.

The application relates to the field of packaging materials and specifically discloses a high-strength paperboard which comprises a core layer and a surface layer, the core layer comprises a core outer layer and a core inner layer, the core outer layer comprises the following components: unbleached kraft softwood pulp, cotton pulp, calcined kaolin, carboxymethyl cellulose and cationic polyacrylamide, and the core inner layer comprises the following components: hardwood pulp, mechanical pulp, microfibrillated cellulose and cationic starch. The double-layer differential structure design is adopted, the core outer layer is constructed with a high proportion of unbleached kraft softwood pulp and cotton pulp to form a long-fiber rigid skeleton, the calcined kaolin and the carboxymethyl cellulose are matched to fill the fiber gaps, a main bearing layer with high density and high rigidity is formed, the core inner layer is formed with hardwood pulp, mechanical pulp and microfibrillated cellulose to form a buffer layer with low density and high elasticity, so that the paperboard has excellent compression resistance, bending resistance and impact buffering capacity under the same basis weight, and the warping deformation is inhibited, and the strength, toughness, dimensional stability and cost control are synergistically improved.

The present invention relates to a packaging material for nicotine pouches, comprising cellulose fibers and thermoplastic material fibers, wherein the content of the cellulose fibers is 40% to 80% by weight of the total weight of the packaging material for nicotine pouches, and the content of the thermoplastic material fibers is 20% to 60% by weight of the total weight of the packaging material for nicotine pouches.

The present application addresses the problem of providing a carbon material precursor having, as a main component, cellulose-based fibers that are sustainable biomass resources, the precursor having little shrinkage due to carbonization treatment. The present invention also addresses the problem of providing a method for producing a carbon material that is capable of suppressing shrinkage due to carbonization even when a precursor having cellulose-based fibers as the main component is used. A carbon material precursor is prepared from an unfired fiber mixture containing cellulose fibers and synthetic polymer fibers, the content of the cellulose fibers in the unfired fiber mixture being 50% by weight or more, and the content of the synthetic polymer fibers in the unfired fiber mixture being 5% by weight or more but less than 50% by weight. The synthetic polymer fibers have a higher thermal decomposition temperature than the thermal decomposition temperature of the cellulose-based fibers and do not melt at or below the thermal decomposition temperature of the cellulose-based fibers. A carbon material is obtained by firing such a carbon material precursor.

The invention discloses a method for manufacturing a multiply paperboard comprising the steps of: - forming a web comprising at least a top ply, a back ply, and a middle ply arranged between the top ply and the back ply, wherein the middle ply is formed from a first furnish comprising at least 50 wt% of a HT-CTMP and 0.1 – 10 wt% of glue pulp based on the total dry weight of said first furnish, wherein said glue pulp has a Schopper Riegler (SR) value in the range of 55- 84 as measured according to standard ISO 5267-1 and a mass fraction of fines of less than 25% as measured according to standard ISO 10376:2011, - subjecting the thereof formed three-ply web to pressing in at least one shoe press, and - drying the web. It has been found that the combination of using the said furnish mixture including HT-CTMP and glue pulp with an SR value within said range enables efficient dewatering by use of a shoe press and gives rise to a paperboard with high bulk but maintained or improved strength properties.

The present invention relates to lignocellulosic nanofibres (LNFC) or biopolymeric reinforcing nanoadditive as a mechanical reinforcement of low-molar-ratio phenol formaldehyde (PF) and urea formaldehyde (UF) thermosetting adhesives, wherein the use of natural nanocompounds based on lignin and cellulose makes the nanoadditive or nanofibre a "green" or environmentally friendly additive, said additive being useful in the production of wood-based composites. The LNFCs are made by means of a process that does not involve chemical additives and which is based on thermomechanical wood pulp, using microshredding and high-pressure microfluidsation. The present natural nanoadditive or natural reinforcement fibre is intended for the industry of manufacturing plywood, medium density fibreboard (MDF) and particleboard.

There is provided a method of producing a paper- or linerboard having a grammage measured according to ISO 536:2019 of 170-310 g / m2 and comprising a print layer, a middle layer and a back layer, wherein the middle layer is formed from a middle layer furnish comprising at least 25% by dry weight CTMP and the back layer is formed from a back layer furnish comprising an unbleached pulp, such as an unbleached kraft pulp, said method comprising the step of subjecting a multi-layered web at a speed of at least 600 m / min to pressing in a press section comprising a first and a second double-felted shoe press nip arranged in series, wherein the total press impulse of the double-felted shoe press nips is at least 95 kPa*s, preferably at least 100 kPa*s.

A system and process for producing pulp and other bioproducts from non-wood raw materials are described. The non-wood raw materials are screened, desilicated, impregnated, mechanically refined to obtain a pulp stream, and then subjected to oxygen-alkali treatment. Lignin and silica are separated from the pulp stream to obtain pulp. Desilication is carried out at a first temperature using warm water, an alkaline solution, and / or an alkaline liquor with a low alkali charge to selectively separate silica from the non-wood raw materials. Impregnation is carried out at a second temperature using an alkaline solution with a low alkali charge to selectively separate lignin from the non-wood raw materials and prepare the pulp for mechanical refining. The oxygen-alkali treatment is carried out at a third temperature to separate more lignin from the pulp stream.

The invention provides low-trace stiffness cigarette packet paper and a preparation method thereof. The preparation method comprises the following steps: making raw paper; the raw paper comprises a surface layer, a core layer and a bottom layer which are sequentially stacked; wherein the paper pulp of the surface layer and the paper pulp of the bottom layer comprise NBKP pulp and LBKP pulp, the proportion of the NBKP pulp is 15%-30%, and the proportion of the LBKP pulp is 85%-70%; the core layer comprises 50 + / -10% of mechanical pulp and the balance of NBKP and / or LBKP pulp; the amount of the whole filler of the raw paper is 8-13%; respectively carrying out surface sizing on the surfaces of the two sides of the raw paper; and coating the front surface of the glued raw paper. According to the preparation method of the cigarette packet paper with the low pressure mark stiffness, the cigarette packet paper with the high stiffness and the low pressure mark stiffness is developed through model selection of raw materials and optimization of technological parameters of a paper machine, the problem of cigarette packet glue failure can be avoided, the forming effect of cigarette packets can be maintained, and the preparation method is suitable for a high-speed cigarette packet machine and cigarette packet products with high forming requirements.

Systems and processes are described for producing pulp and other bioproducts from non- wood feedstock. Non-wood feedstock is screened, desilicated, impregnated, and mechanically refined to obtain a pulp stream which is then subjected to oxygen-alkali treatment. Lignin and silica are separated from the pulp stream to obtain the pulp. Desilication is performed at a first temperature with hot water, an alkaline solution, and / or an alkaline liquor having a low alkali charge to selectively separate silica from the non-wood feedstock. Impregnation may be performed at a second temperature with an alkaline solution having low alkali charge to selectively separate lignin from the non-wood feedstock and prepare the pulp for mechanical refining. The oxygen-alkali treatment is performed at a third temperature to separate more lignin from the pulp stream.

The invention discloses a method for manufacturing a multi-ply paperboard comprising the steps of: - forming a web comprising at least a top ply, a back ply and a middle ply, wherein the middle ply is formed from a first furnish comprising at least 50 wt% of a CTMP or HT-CTMP, or a mixture thereof, and 0.1–15 wt% of a first fiber-based bulking agent based on the total dry weight of said first furnish, wherein the first fiber-based bulking agent has a Schopper Riegler (SR) value in the range of 70-100 as measured according to ISO 5267-1:1999, a tensile index less than 70 Nm / g as measured according to ISO 1924-3:2011 and an apparent bulk density less than 900 kg / m3 as measured according to ISO 534:2011, - subjecting the thereof formed web to pressing in at least one shoe press, and - drying the web.

This application provides a paper pulp, a method for producing paper pulp, and a paper pulp product. The method for producing paper pulp includes: crushing bamboo shoot shells to obtain crushed materials; mixing the crushed materials with cooking, cooking the mixture to obtain slurry; washing the slurry to obtain waste liquid and washed slurry; purifying the washed slurry to obtain the paper pulp.

A method of producing moldable cellulosic fibers from a cellulosic fiber material, the method comprising: mechanically pre-treating a feedstock to form a fibrous material having a fiber length distribution such that at least 90% of the fibers have a length of less than about 40 millimeters; dewatering the fiber ingredient to produce a first filtrate and a dewatered fiber cake having a moisture content of less than about 50% (by weight); pulping the dehydrated fiber cake at a temperature in the range of 45 to 95 DEG C to produce a pulpified fiber material having a consistency of less than about 5% fiber (by weight); washing the pulpified fibrous material to produce a cake of cellulosic fibers having a consistency of at least 10% fibers (by weight) and a second filtrate; and refining the cake of cellulosic fibers in at least one disc mill to produce moldable cellulosic fibers.

A differential density absorbent towel paper product comprising at least one absorbent towel paper web is disclosed. The absorbent towel paper web has: (a) from about 20% to about 90% by weight of the dry fiber basis of the absorbent towel paper web of a refined soft wood pulp fiber mixture, (b) pulp fibers selected from the group consisting of hard wood fibers, non-wood fibers, recycled fibers, synthetic polymer fibers, bleached eucalyptus kraft fibers, and combinations thereof and, (c) not more than about 10% by weight moisture. The refined soft wood pulp fiber mixture has: i) from about 18.5% to about 88.5% by weight of soft wood pulp fiber; ii) from about 0.25% to about 5.0% by of cationic strengthening polymer; and, iii) from about 0.05% to about 20% by weight of cellulose nano-filaments.

The invention discloses a paperboard comprising at least three plies: a first ply forming a top ply, a second ply forming at least one middle ply and a third ply forming a back ply, wherein the second ply is formed from a middle ply furnish comprising at least 50 % by weight of pressure groundwood (PGW) pulp, 0.1 - 1 % by weight of carboxymethyl cellulose (CMC) and 0.1 - 5 % by weight of cationic starch. The PGW pulp has a Freeness of at least 390 ml and comprises less than 17 % dry weight of a fine fraction that is able to pass through a 200 mesh screen.