Method of production of paper (versions) and paper product made by this method

FIELD: production of improved starch compositions and methods of use of improved starch compositions.

SUBSTANCE: proposed method includes use of starch component containing cationized cross-linked starch at viscosity of from 10 to 3000 cps. Production of paper includes the following stages: boiling the starch component at temperature of 165°C, dehydration of paper composition (paper fibers, inorganic filler, starch) and control of rate of dehydration and/or holding the first pass in the course of dehydration through change in temperature (by at least 10°C) of starch composition boiling.

EFFECT: possibility of performing modifications in accordance with variants on wet end of paper machine.

21 cl, 6 dwg, 2 tbl

 

The scope of the invention

The present invention relates to an improved starch compositions and methods of use of the improved starch compositions. In particular, the present invention is directed to the creation of the starch compositions intended for use in the processes of making paper, and to create ways of preparing, handling and use of starch compositions in the production of paper products.

Prerequisites to the creation of inventions

Various paper products made from fibers, and these products are often made from an aqueous suspension which contains modified cellulose fibers obtained from various plants. Such suspension get wet end of the paper machine where the paper fibers form a diluted aqueous suspension and add a variety of materials, previously distribution on the ribbon, the paper machine. The water is then removed in a controlled way from the suspension to obtain paper web, which is pressed and dried to create a finished paper product.

Various additives can be introduced into the suspension to improve the paper manufacturing process and to improve the aesthetic and functional properties of the finished paper. These additives can soderjatelinii composition, introducing the wet end of the paper manufacturing process, to improve drainage and retention, increase strength and improve properties of forming paper. Starch composition can improve the absorption of printing ink, to reduce lateral spreading (spreading) of printing ink, as well as to improve the formation and image contrast. Starch compositions can also increase the integrity of the paper surface, resulting in reduced plucking when such use as printing and Photocopying.

Other ingredients that can be put in the paper, are particles, including particles of special clays and silica, as well as other functional fine particles, and these particles are often added at the wet end of the papermaking machine. Depending on the type of paper and the characteristics of the suspension can be introduced to different microparticles. One of the problems associated with the use of microparticles during the paper manufacturing process, is the fact that not all particles are retained on a paper canvas in the formation of paper. The microparticles, which are not held on the canvas, often go to waste, which leads to an increase in the cost of paper production. It is therefore desirable to increase the retention of particles.

Drainage or obeso is Ivana is another important characteristic in the manufacture of paper, because it determines the speed with which the paper machine can remove the water from the cloth. Usually improved dehydration corresponds to a higher speed paper machines and paper exit, i.e. leads to improved performance. Manufacturers of paper tend to keep all the fibers and particles on the canvas at the highest cost possible speed, without compromising product quality. However, manufacturers of paper, trying to maintain the quality of the paper, are often faced with limitations associated with drainage, it is therefore desirable to have a high performance drainage, so that it was possible to produce paper of good quality with high speed.

Despite the fact that the paper manufacturers and suppliers of the ingredients of the paper understand that desirable high performance retention of particles and drying, a significant problem in obtaining a guaranteed higher quality paper creates what system of paper making are different and can have significant deviations. These deviations can be as a result of changes to the ingredients in the composition of paper and equipment tolerances for the manufacture of paper. These variations make it difficult to achieve higher quality paper at high speed due to changes in the characteristics of the retention of particles and drying.

Currently, most of the ingredients that are added to the slurry for the manufacture of paper, optimized for use in specific conditions. This is true, for example, starch compositions that add to the wet end of the paper manufacturing process. Unfortunately, working conditions, equipment for making paper with change over time due to changes of the ingredients (suspension) and system settings (paper manufacturing). This raises the need to ensure satisfactory drainage and retention of particles in the range of various conditions of the manufacturing process of paper.

Summary of invention

The present invention in General relates to the creation of starches, for example, cationic crosslinked starch, and to the use of these starches in paper production. More specifically, the present invention is directed to the creation of starch and its use in the wet end of the papermaking machine. The present invention is intended, in particular, to specify properties of starch wet end of the specific systems and allows modification of the properties of starch in accordance with variations on the wet end of the papermaking machine.

Starch can also be modified during production for MF is t adjust the functional properties of starch in the paper manufacturing process. Due to selective changes in the level of crosslinking of the starch you can change the characteristics of the drainage and retention of particles of a composition of paper containing starch, which allows you to specifically set the properties of starch for enhanced operational parameters, depending on the characteristics of the composition of the paper, in which it will be used.

Properties of starch can be optionally set directly before using it on the wet end of the papermaking machine, in order to adapt the starch to the specific conditions existing in the paper machine, which can improve the drainage and retention of particles. This configuration is produced, for example, by changing the temperature at which the starch composition is welded previously additive on the wet end, and by changing the period of time of cooking of the starch, pressure changes, which produce starch, and/or by changing the content of dry substances in the starch to conduct cooking. By changing these parameters, individually or in the aggregate, the properties of starch can be modified and adjusted in accordance with the specific conditions of the various processes of making paper. For example, by cooking at higher or lower temperatures, the properties of starch can be changed is by thus to improve the performance parameters on the wet end.

In accordance with the first embodiment of the present invention proposes a method of making paper, which involves the use of a composition of paper containing cellulosic fibers in aqueous suspension, which is added to the starch composition. Starch composition is typically a crosslinked cationic starch. Starch is welded previously introduced in the furnish, at the temperature of boiling below 330°F, mostly from 180 to 250°F, and even better, at a temperature below 220°F or 230°F. These temperature cooking are the average temperatures of cooking, which correspond to average temperatures, obtained by averaging two or more measured temperatures during cooking.

Particles, including nanoparticles, enter into the composition of the paper for improving the operational parameters of the machine, such as drainage and retention of particles, and these particles have an average diameter of less than 1.0 μm, and mostly less than 0.1 μm. Suitable particles include particles of various silicas and clays.

Cationic crosslinked starch in accordance with the present invention is administered as an additive to the wet end in the composition of the paper, which has a pH in the wet the rates from approximately 4.0 to 9.0. Total paper production process, including the term "wet end"described in the book Pulp & Paper Manufacture, Vol. III. Papermaking and Paperboard Making, R. G. McDonald, editor, J.N.Franklin, tech. editor, McGraw Hill Book Co., 1970.

In a specific embodiment of the present invention, starch and its preparation are used to enhance dewatering compositions of the paper. Since dehydration of the composition of the paper is in the process of making paper, we evaluate the speed of dehydration. If the rate of dehydration is insufficient, change the cooking temperature of the starch, in order to change the properties of dehydration. Changing the cooking temperature should be sufficient to change dehydration or deduction on the first pass of the composition of the paper. Usually the temperature change exceeds 1°F, a is preferably at least 5°F. In specific embodiments, the implementation of the present invention, the temperature change is from 5 to 10°F, and in some embodiments, implementation of the present invention, the temperature change is at least about 10°F. the Temperature increase in some cases and lower in other embodiments, depending on the characteristics of the dehydration or drying, earlier changes in temperature cooking.

Sometimes it is necessary to define an appropriate change in the tempo of the atmospheric temperature due to repeated temperature changes, the subsequent evaluation of paper properties. Such repeated temperature changes allow for manual evaluation and adjustment of the properties of the composition of the paper. For example, in the case when the properties of dehydration are poor or have a tendency to deterioration, the temperature may initially be reduced to the preset value (for example, on 5°F). If this lowering of the temperature leads to improved dewatering, then the temperature can be maintained at the new level. Alternatively, the temperature may be further reduced to further improve dewatering. If this lowering of the temperature leads to improved properties of dehydration, then the temperature can be maintained at the new level (or in addition to lower to further improve dehydration). However, if the temperature decrease does not improve the properties of the dehydration, the temperature may again be raised to the previous level. Alternatively, the temperature may be partially raised to a higher level.

If the initial lowering of the temperature leads to improved properties of the dehydration, the temperature usually increases relative to the initial temperature, in order to improve the properties of dehydration. If the properties of dehydration do not improve, then it is Yes, the temperature should be returned to the original temperature or returned to an intermediate temperature, in the range from the initial temperature to high temperature. If the properties of dehydration improves, then the temperature can be maintained at a higher level, or re-raise to a higher temperature.

Specified and other similarly use the temperature at which the cooked starch to modify the properties of the obtained starch, resulting in you can set these properties depending on the settings on the wet end of the papermaking machine. In addition to setting properties retention and drainage by adjusting the cooking temperature of the starch, adjusting these properties can be produced by pressure changes during cooking of starch and due to changes in the content of dry substances in the starch until it is boiling. For example, starch is usually carried out in a jet digester under pressure less than 100 pounds per square inch; and the starch is usually injected in the jet digester at a solids content less than 10 %. Due to a change in pressure or solids content, you can modify the properties of starch composition in accordance with the specific properties of the composition of the paper at the wet end, which is injected starch composition.

Changing the temperature, pressure, and solids content can be carried out individually for improving the surveillance of operational parameters on the wet end, but together, in order to change the properties of the starch. For example, can be changed all three of these parameters, and can also be changed two parameters, for example, temperature and pressure; temperature and solids content; or the pressure and the solids content. Moreover, in addition to improved drainage and retention can be obtained and other improvements of properties on the wet end, such as, for example, improving linear speed, which are often observed simultaneously with improvements in drainage and retention.

In accordance with another embodiment of the present invention proposes a method of adjustment during the paper manufacturing process. This method provides for the regulation of the temperature of cooking starch composition, in order to obtain improved properties of drainage or retention of the composition of the paper. This method involves the use of the composition of the paper, which contains cellulose fibers and microparticles in water suspension, and the use of a starch composition, the composition of which is selected for introduction into the composition of the paper. A portion of the starch composition is welded at the initial temperature and then introduced into the composition of the paper. The composition of the paper is then dehydrated to form the fabric of cellulose fibers. Assess the speed of dehydration or hold the deposits of particles in aqueous suspensions and if dehydration occurs with poor speed, then change the temperature at which the starch composition is welded, at different temperatures, in order to change the speed of the dewatering of aqueous suspensions.

A brief summary of the invention is not intended to describe all its variants. These and other features of the invention will be more apparent from the subsequent detailed description, given as an example having no limiting character and described with reference to the accompanying drawings.

Brief description of drawings

Figure 1 shows a graph of the distribution of particle size for the sample of starch wet end, one of which is sewn, and the other is not stitched.

Figure 2 shows a graph of the average particle size of crosslinked cationic starch cooked at different temperatures inkjet cooking.

Figure 3 shows a graph of the distribution of particle size for the sample of additives on the wet end.

Figure 4 shows a graph of drain crosslinked cationic starch and not crosslinked cationic starch, which were welded at different temperatures.

Figure 5 shows a graph of the viscosity of crosslinked cationic starch and not crosslinked cationic starch, which were welded under different temperature and the arts.

Figure 6 6 shows a graph of an average particle size of crosslinked cationic starch and not crosslinked cationic starch, which were welded at different temperatures.

Although in the example described preferred specific way of carrying out the invention, it is clear that it specialists in this field can be amended and supplemented, which do not extend, however, beyond the scope of the following claims.

Detailed description of the invention

The present invention in General relates to the creation of starches, including cationic crosslinked starch, and to the use of these starches in the manufacture of paper. More specifically, the present invention is directed to creating cationizing cross-linked starch and the use of such starch wet end of the papermaking machine. Starch adapted to changing conditions at the wet end and allows modification (properties of starch) in accordance with variations on the wet end of the papermaking machine.

In accordance with the first aspect of the present invention, cationic starch which has been crosslinked after kationirovannykh add in the pulp or in the composition of the paper during paper manufacturing. The starch is cooked earlier introduction to acrom the end of the paper machine, and the cooking were set in such a way as to improve the properties of the composition of the paper at the wet end, such as the retention of particles and drying the composition paper. This way, you set the properties of the starch, so that they meet specific conditions at the wet end of the papermaking machine.

In the following detailed description of the invention is indicated specific starch compositions, methods of job (fit, adjust properties of starch compositions in accordance with the terms of the paper manufacturing process, and describes how to improve performance parameters of the paper manufacturing process, including improving drainage and improve retention of the first pass and retention of microparticles.

A. Modified starch composition

In accordance with the first aspect of the present invention, offers a starch composition which is suitable for use in the wet end of the papermaking machine. Starch compositions in accordance with the present invention possess properties that allow them to modify the cooking process, in order to improve operational parameters during the paper manufacturing process.

The starch may be derived from corn, such as corn, waxy or dent corn), potatoes, with the RHS, tapioca, wheat, rice, etc. Typically use corn starch, preferably corn starch dent, and even better, cationically starch corn in the dent. The starch should have a hydroxyl group or other functional groups that allow for the stitching. The following describes additional properties related to the levels of the fusion viscosity, with substitution levels and particle size.

Starch is usually sewn using a binder that is chemically active with respect to the hydroxyl groups of starch. Cross-linked starch allows you to have a greater range of particle sizes compared to non-cross-linked starch. This greater range of particle sizes creates enhanced opportunities to improve operational parameters on the wet end. Not limiting myself to any theory, it is possible to assume that the improvement of the operational parameters are in the case when the size of the starch particles is closely correlated with the sizes of the different particles in the composition of the paper. Despite the fact that the starch particles can be smaller than that of the fibers, and larger than the additive particles, we can assume that there is a correlation between the size of various particles (fiber, starch and microparticle).

We now turn to a consideration of figure 1, which shows the profiles of RA is a measure of the particles are not crosslinked cationic starch corn dent and crosslinked cationic starch corn in the dent. You can see that is not crosslinked cationic starch corn in the dent has a narrower distribution of particle sizes, while the crosslinked cationic starch has a wide distribution of particle sizes. It can be assumed that a wider distribution of particle size provides a greater probability of collision (interaction) with each other particles in the composition of the paper at the wet end and particles in the starch, resulting in improved retention of microparticles.

The composition of starch is a staple, which can be selected multifunctional organic or inorganic compound, and a functional group in the binder, such as epoxy or anhydrite, are reactive toward hydroxyl groups in the starch. Starch can be made polyepoxide compounds, such as polyaminopolycarboxylate resin, phosphorus oxychloride, 1,4 butanediol, diglycidyl ether, dianhydride, acetates and polyfunctional silanes. As the stapler can be used also trimetaphosphate sodium. These and other staplers and methods of crosslinking are described in U.S. patent No. 3790829; 3391018; 3361590 and 5122231.

The viscosity of the starch

Typically, the level of crosslinking significantly affect the viscosity of the starch. Thus, the viscosity can be set partially midrange is t changes in the level of crosslinking. The amount of crosslinking is a function of time and type of stapler, as well as the reaction conditions, all of these parameters are chosen to ensure a viscosity within the specified range.

Cationic crosslinked starch is usually sewn to the viscosity of the hot pasta in the range of approximately from 10 CP to 3000 CP, usually approximately from 50 CP to 3000 CP, and mainly about 200 CP to 3000 CP, when measured on a Brookfield viscometer, with the content in the starch 2.0% of dry matter at 95°With, at 20 rpm using spindle number 21, in accordance with the methods described in U.S. patent No. 5122231.

Alternatively, the viscosity of the starch can be measured using fracture toughness in accordance with the methods described in U.S. patent No. 5368690, although this technique is less accurate in measuring high viscosity starches. Fracture toughness is usually more than 85%, and mostly more than 90%. In preferred embodiments of implementing the present invention, the viscosity of greater than 95%.

Substitution levels of starch

Suitable starch composition mainly represent cationic starches, which retain a positive charge when dissolved in water. Such starch is predominantly contains Quaternary of nonammonia, which provides enhanced flexibility in pH. Often this contains Quaternary ammonium ion starch is obtained by epirizole hydroxyl groups with the appropriate agent epirizole. As with cationic characteristics of the agent epirizole use, for example, (3-chloro-2-hydroxypropyl) trimethyl ammonium chloride, Quaternary salt of methyl chloride N-(2,3-epoxypropyl) amine or N-(2,3-epoxypropyl) dibutylamine or N-(2,3-epoxypropyl) methylaniline.

Used herein, the term "degree of substitution" (DS) can be defined as the average number of hydroxyl groups in each block of anhydroglucose obtained using a replacement groups. DS is used as a measure of the charge cationizing and cross-linked starch, and the degree of substitution is associated with an average number of singly charged cations hydroxyl groups in each block anhydroglucose.

Determination of the degree of substitution is contained in the publication STARCH: Chemistry and Technology, second edition, R. L. Whister, J.N.Bemiller, and E. F. Paschall, editors. Academic Press, Inc., 1984. Starch is usually cationizing to the degree of substitution (DS) of more than 0.005 but not more than 0.100, and typically about 0.030 to 0.070. Starch is mostly DS in the range of 0.030 to 0.040.

The starch may be cationization using any known method, such as conducting the reactions is in an alkaline environment with a tertiary or Quaternary amines, with possible subsequent neutralization, washing and drying. Known methods of cationization starch described in U.S. patent No. 4146515 and 4840705. In accordance with one aspect of the present invention, corn starch cationized by using the reaction of starch with (3-chloro-2 hydroxypropyl) trimethyl ammonium chloride in an alkaline medium, formed by sodium hydroxide, resulting in a gain of cationic (2-hydroxypropyl) trimethyl ammonium chloride starch ether with a molar degree of substitution (DS) ether starch in the range of 0.030 to 0.040.

The particle size of the starch

Starch compositions in accordance with the present invention are preferred in the sense that they allow the modification of the particle size given the nature of starch composition and characteristics of cooking, including temperature, pressure, and solids content. This allows you to change the size of the particles in order to provide the most favorable properties in the composition of the paper at the wet end. The particle size of starch can be determined by analysis of the size distribution of the particles, for example, using Mie scattering theory, which is used in the particle size distribution analyzers, manufactured by Horiba, Inc., including the particle size distribution analyzer type LA910. Mi those who scattering theory does not provide a direct measurement of the diameter, and gives at least the relative size of the particles.

We now turn to a consideration of figure 2, which shows an example of a distribution of particles in a starch composition made in accordance with the present invention. The distribution of particles of cross-linked starch varies significantly depending on the cooking temperature, which in this example varies from 190 to 265°F. the Maximum particle size obtained when low temperature cooking. Due to changes in temperature cooking, you can change the average particle size, it is possible to accurately specify the size of the particles in accordance with the specific composition of the paper at the wet end, which is injected starch.

C. the Ingredients of microparticles

In the composition of the paper are also introducing microparticles, as they facilitate drainage and can work as a flocculant. Suitable microparticles are particles of silica and clays. The concentration of particles introduced into the furnish at the wet end in accordance with the present invention, varies depending on the desired properties of the finished paper product, together with received levels of retention of particles. Microparticles are typically injected at a concentration of less than 5.0 pounds per ton of fiber, and mostly less than 2.0 pounds per ton of fiber.

The microparticles typically have average is iameter less than 1.0 μm, and mostly less than 0.5 μm. A means of drainage, such as colloidal silica, often has an average particle diameter of about 0.1 μm, and fillers typically have an average particle diameter of 1 to 50 μm, conglomerates latex have an average particle diameter of 10 to 100 μm, and the fiber often has an average size of 200 μm or more.

We now turn to a consideration of figure 3, which shows the distribution of particle size (particle size) for the typical ingredients to the wet end, including silica, titanium dioxide, precipitated precipitated calcium carbonate (PCC) and white water. You can see that the particle size varies depending on the particle type. The silica has a particle size of about 0.10 μm, the titanium dioxide has an average particle size of approximately 0.8 μm in the range from 0.5 to 1.0 μm. RCC has a particle size in the range from approximately 1.0 μm to 10 μm. White water has a particle size in the range from less than 1.0 μm to 10 μm. Depending on the amount of added particles, you can set the optimum drainage and retention of particles in the starch composition. It is often necessary to set the particle size of the starch so that it corresponded to the different sizes of the microparticles. This has to be done in the case when the sizes of the microparticles vary during the paper manufacturing process, the and by deliberately changing the particle size or concentration, or due to unintended changes in the manufacturing process of the composition of the paper.

C. Conditions for preparing starch

The present invention allows the cooking of starch compositions in such a way that the properties of starch, including particle size and distribution of particle sizes will be optimized to match the properties (composition paper at the wet end, including compliance with the particle size and distribution of particles on the wet end. Not limiting myself to any theory, it is still possible to assume that the variation of the particle size of the starch compositions correlate with changes in the characteristics of the drainage and retention of particles. In that case, when the particle size of the starch properly correlated with the sizes of organic and inorganic particles (e.g., fibers, latex)is added to the starch, the composition of the paper gets improved properties of drainage and retention of particles, as well as other favorable properties. A wide distribution of particle sizes in the starch may be obtained by appropriate selection of the modes of cooking starch in the mash Tun. The ability of such changes of particle size and distribution of particle sizes, which provides a match with the characteristics of the wet end of the papermaking machine, allows the floor what s the best retention properties of the particles and drying.

D. How to adjust the properties of a starch composition

Changing the cooking temperature

In accordance with the first embodiment of the present invention, the properties of starch modified by changing the cooking temperature of the starch, and in particular, the temperature at which produce inkjet starch. In specific embodiments, use advanced methods of adjusting the cooking temperature of the starch to improve dewatering characteristics of the composition of the paper and/or retention of microparticles. Since dehydration of the composition of the paper is in the process of making paper, we evaluate the speed of dehydration. If the rate of dehydration is unsatisfactory, then the cooking temperature of the starch to change in order to change the properties of dehydration.

Changing the cooking temperature must be sufficient for the proper change of dehydration or hold the first pass of the composition of the paper. Therefore, temperature changes must be large enough to affect the properties of the composition of the paper. Usually the temperature is changed to the value of over 1°F, and mostly more than 5°F. In specific embodiments, the temperature change on the order of 5 to 10°F, and in some embodiments, the change in temperature which is at least about 10° F, and the temperature in some embodiments, increase, and in other embodiments, lower, depending on the properties of dehydration or drying prior to the change of temperature of cooking.

In a specific embodiment, the paper manufacturing process involves the operation of cooking the starch component, dehydration composition of paper, and then adjust the speed of dehydration due to changes in temperature cooking starch component. The first operation, namely, boiling starch component, provides for the conduct of cooking when the first average cooking temperature below 330°F, during the first period of time, cationizing cross-linked starch, which has a viscosity of hot pasta in the range of approximately from 50 CP to 3000 CP, measured on a Brookfield viscometer at a solids content in the starch 2.0% at a temperature of about 95°With, at 20 rpm using spindle No.21. The composition of the paper contains cellulose fibers in aqueous suspensions of inorganic particles, which comprise at least 50 wt.% particles having an average particle size of not more than 1 μm, and cooked starch component. The rate of dehydration set due to cooking a starch composition at a second temperature that differs by at least 10°F from the first high temperature cooking. In specific the fir embodiments, the second average cooking temperature is from 200 to 250° F, and in other embodiments, the second average cooking temperature is less than 230°F. the Particles may be particles of silica, clay, and combinations thereof.

Additional operations may include determining the retention of particles and the temperature change to adjust retention of particles. Starch composition may be melted in a jet digester under pressure less than 150 pounds per square inch. In specific embodiments, the starch is introduced into the jet digester at a solids content from 1 to 10%.

Because of the complexity properties of the composition of the paper, sometimes it is necessary to determine the proper temperature change due to the iterative (repetitive) temperature changes, and the subsequent evaluation of paper properties. Such temperature changes are produced from the original (initial) temperature of the cooking, and after each change to determine whether there was improvement in the retention of particles, drying or the quality of the paper product. These changes are aimed at optimizing the properties of the starch due to changes in temperature cooking until, until you reach the preferred range of properties.

For example, in the case when the properties of dehydration are poor or have a tendency to deterioration, the temperature may initially be reduced by setting Zn is an increase (for example, on 5°F). If this lowering of the temperature leads to improved dewatering, then the temperature can be maintained at the new level. Alternatively, the temperature may be further reduced to further improve dewatering. If this lowering of the temperature leads to improved properties of dehydration, then the temperature can be maintained at the new level (or in addition to lower to further improve dehydration). However, if the temperature decrease does not improve the properties of the dehydration, the temperature may again be raised to the previous level.

Alternatively, the temperature may be partially raised to a higher level. If the initial lowering of the temperature leads to improved properties of the dehydration, the temperature usually increases relative to the initial temperature, in order to improve the properties of dehydration. If the properties of dehydration do not improve, then the temperature must be returned to the original temperature or returned to an intermediate temperature in the range from the initial temperature to high temperature. If the properties of dehydration improves, then the temperature can be maintained at a higher level, or re-raise to a higher temperature. In this way use tempera is ur, when cooked starch, to modify the properties of the obtained starch, resulting in you can set these properties depending on the settings on the wet end of the papermaking machine.

The change in pressure cooking

In accordance with another embodiment of the present invention, the properties of starch modified by changing the pressure under which produce starch, and in particular pressure at which the produce inkjet starch. As during the paper manufacturing process is dehydration composition paper, we evaluate the speed of dehydration or retention of particles. If the speed of dehydration or retention of particles are unsatisfactory, then produce a change in the pressure cooking of starch, in order to change the properties of dehydration or retention of particles. The change in pressure cooking should be sufficient for the proper change of dehydration or hold the first pass of the composition of the paper.

Typically, the pressure change exceeds cooking at least 1 psi (pound per square inch), and mostly exceeds 5 psi. In specific embodiments, the change in pressure cooking is from 10 to 60 psi, and in some embodiments, the pressure change is at least about 20 psi, in some embodiments, the pressure increases is t, in other embodiments, the pressure decrease, depending on the characteristics of the dehydration or drying of earlier changes of pressure cooking.

In a specific embodiment, the paper manufacturing process involves the operation of cooking the starch component, dehydration composition of paper, and then adjust the speed of dehydration due to a change in pressure cooking the starch component. The first operation, namely, boiling starch component, provides for the conduct of cooking cationizing cross-linked starch, which has a viscosity of hot pasta in the range of approximately from 10 CP to 3000 CP, typically from 50 to 3000 centipoise, and most of about 200 CP to 3000 CP, measured on a Brookfield viscometer at a solids content in the starch 2.0% at a temperature of about 95°using spindle No. 21 at 20 rpm

The composition of the paper contains cellulose fibers in aqueous suspensions of inorganic particles, which comprise at least 50 wt.% particles having an average particle size of not more than 1 μm, and cooked starch component. The rate of dehydration set due to cooking a starch composition at a second pressure that is different by at least 10 psi from the first medium pressure cooking.

Additional operations may be included the ü in the definition of retention of particles and the pressure change is to adjust the retention of particles. In specific embodiments, the starch is introduced into the jet digester at a solids content from 1 to 10%.

Because of the complexity properties of the composition of the paper, sometimes it is necessary to determine the proper pressure change due to the iterative pressure changes and the subsequent evaluation of paper properties. Such pressure changes are produced from the original (initial) pressure cooking, and after each change to determine whether there was improvement in the retention of particles, drying or the quality of the paper product. These changes are aimed at optimizing the properties of the starch due to a change in pressure cooking until, until you reach the preferred range of properties.

For example, in the case when the properties of dehydration or retention are poor or have a tendency to deteriorate, the pressure may initially be reduced by a specified amount (for example, 10 psi). If such a reduction leads to improved drainage or retention, then the pressure can be maintained at the new level. Alternatively, the pressure may be further reduced to further improve drainage or retention. If such a pressure decrease leads to improved properties of dehydration, then the pressure can be maintained at the new level (or further reduce d the I further improve dehydration). However, if this pressure drop does not improve the properties of dehydration, then the pressure can again be increased to the previous level.

If the initial pressure decrease does not lead to improved properties of dehydration or retention, the pressure usually increase relative to the original values in order to improve the properties of dehydration or retention. If these properties are not improved, then the pressure must be returned to the original pressure or returned to the intermediate pressure in the range from the initial pressure to high pressure. If these properties are improved, then the pressure can be maintained at a higher level, or re-raise to a higher pressure. Specified and other similarly use the pressure at which the cooked starch to modify the properties of the obtained starch, resulting in you can set these properties depending on the settings on the wet end of the papermaking machine.

Change the content of dry substances

In accordance with another embodiment of the present invention, the properties of starch modified by changing the content of dry substances in the starch, which produce starch, and in particular, the content of dry substances, which produce a jet cooking KRA is small. In specific embodiments, use improved starch and improved ways to improve properties of dehydration composition of paper and/or retention of microparticles. As during the paper manufacturing process is dehydration composition paper, we evaluate the speed of dehydration. If the rate of dehydration is unsatisfactory, then produce a change in the content of dry substances in the starch, in order to change the properties of dehydration.

Change the content of dry substances should be sufficient for the proper change of dehydration or hold the first pass of the composition of the paper. Usually changing the solids content exceeds 1%, and mostly exceed 2%. In specific embodiments, the change in the solids content is from 3 to 10%, and in some embodiments, the change in the solids content is at least about 5%, and the content of dry substances in some embodiments, increase, and in other embodiments, reduce, depending on the characteristics of the dehydration or drying prior to changes in the content of dry substances.

In a specific embodiment, the paper manufacturing process involves the operation of cooking the starch component, dehydration composition of paper, and then adjust the speed dehydration for the odd changes in the content of dry substances in the starch component previously holding boiling in the jet digester. The first operation, namely, boiling starch component, provides for the conduct of cooking cationizing cross-linked starch in the jet digester. Starch component to conduct cooking is the viscosity of the hot pasta in the range of approximately from 10 CP to 3000 CP, typically from 50 to 3000 centipoise, and most of about 200 CP to 3000 CP, measured on a Brookfield viscometer with a small sampler (Small Sample Brookfield Viscometer System (SSB)), spindle No.21 at 20 rpm, when the content of dry substances in the starch 2.0% at a temperature of about 95°C. the Composition of the paper contains cellulose fibers in aqueous suspensions of inorganic particles, which comprise at least 50 weight.% particles having an average particle size of not more than 1 μm, and cooked starch component. The rate of dehydration set due to the cooking of starch composition in the second solids content, which differs by at least 1% of the first average solids content.

In specific embodiments, the second average solids content is from 5 to 6%, and in other embodiments, the second average solids content is less than 5%. Microparticles may contain silica, clay, and combinations thereof.

Additional operations may include determining what their retention of particles and change the content of dry substances for adjusting the retention of particles. In specific embodiments, the starch is cooked in a jet digester under pressure from 10 to 30 pounds per square inch and at a temperature of from 200 to 300° F.

Because of the complexity properties of the composition of the paper, sometimes it is necessary to define an appropriate change in the content of dry substances through iterative changes to the content of dry substances and the subsequent evaluation of paper properties. Such changes produce from the original (primary) content of dry substances, and after each change to determine whether there was improvement in the retention of particles, drying or the quality of the paper product. These changes are aimed at optimizing the properties of the starch due to changes in the content of dry substances until then, until you reach the preferred range of properties.

For example, in the case when the properties of dehydration are poor or have a tendency to deteriorate, the solids content may initially be reduced by a specified amount. If such a reduction leads to improved dewatering, the solids content can be maintained at the new level. Alternatively, the solids content can be further reduced to further improve dewatering. If such a lower solids content leads to improved properties Obispo the tion, then the solids content can be maintained at the new level (or in addition to lower to further improve dehydration). However, if such a lower solids content does not improve the properties of dewatering, the solids content may be again raised to the previous level. Alternatively, the solids content may be partially raised to a higher level.

D. Improvement of operational parameters of the papermaking machine

Under certain conditions it is possible to achieve improvement of operational parameters of the paper machine, for example, by reducing the number of failures tirereplacement that allows you to increase the volume of production. This increased performance may be the result of reducing the amount of paper that does not meet specifications, improve the drainage of the paper stock and increase the speed of the machine.

The starch is cooked and add to the wet end of the papermaking machine in the composition of the paper, which contains pulp fibers. The composition of the paper may contain fiber solid wood, soft wood, or a mixture of fibers of hard and soft wood. Introduction cationizing cross-linked starch can be produced at various points in the paper manufacturing process, including pre is obrazovaniya wet fibrous mass to dry the paper web or sheet. Thus, the starch can be introduced into the process, for example, when the fiber is in the head chamber, grinding machine, hydropulper or in the tank for pulp. The composition of the paper may contain additives, dyes and/or fillers such as clay, caso3, alum and the like, the Present invention mainly allows the use of higher levels of starch and fillers instead of the more expensive cellulose fibers, resulting in receive paper with high strength made from less expensive raw materials within a shorter processing time, with improved retention of fine particles and fillers.

That is the Example

Was prepared raw material for paper production, designed for the comparison of changes in the retention of particles, drying and viscosity when using stitched and not stitched cationic starch dent corn, and the comparison was carried out on the basis of changes in properties of cooking. For each type of starch produced additive 30 pounds of starch per ton of dry wood fiber. The cooked starch was carried out at temperatures ranging from 192 to 265°F, and the solids content was maintained in the range from 1.28 to 1.39%. The average particle size of starch was measured using the analyzer of the distribution of particle sizes Horiba LA910, and drainage was measured with IP is the use of the technique of dynamic drainage Jar. Characteristics of the respective starches are shown in tables 1 and 2.

Table 1 - Crosslinked cationic starch
SampleCooking temperature (°F)Viscosity (centipoise)*Dilution of dry matter (%)The average particle size (µm)Drainage (ml/20 sec)Hold
And1962501.2811841.660.77
In2172051.3911454.762.25
2331501.3710258.663.44
D2451151.347642.164.46
E265951.286138.561.91
*Viscosity Brookfield cooked starch was measured at 150°F, when the solids content (%)in Table 1, using spindle No.21 at 20 rpm

Table 2 - N is crosslinked cationic starch
SampleCooking temperature (°F)Viscosity (centipoise)*Dilution of dry matter (%)The average particle size (µm)Drainage (ml / 20 sec)Hold
F192401.6634.133.861.71
G218301.438.431.460.78
N240201.2310.133.264.12
I265201.385.332.962.84
*Viscosity Brookfield cooked starch was measured at 150°F, when the solids content (%)in Table 2, using spindle No.21 at 20 rpm

The different properties for the two types of starch is shown in figure 4, 5 and 6, on which the graphs are drying, viscosity and particle distribution sizes for crosslinked cationic starch dent corn and not crosslinked cationic starch dent corn, at various temperature jet cooking. Figure 4 shows that in this example, crosslinked cationic starch had the t dynamic drainage in the range of approximately from 200 to 260° F, with a peak of about 230°F. In contrast, non-crosslinked cationic starch has a relatively flat characteristic drying (at lower level than the crosslinked cationic starch).

Moreover, as shown in figure 5, crosslinked cationic starch has a change of viscosity in a wide temperature range. In the example shown in figure 5, crosslinked cationic starch has the highest viscosity at low temperatures and the low viscosity at elevated temperatures, the temperature range extends approximately from 200°F to 265°F. However, in this same temperature range is not crosslinked cationic starch has no significant changes in viscosity.

Figure 6 shows the changes of the distribution of particle sizes in the extended range of inkjet cooking for crosslinked cationic starch and not crosslinked cationic starch. The distribution of particle sizes greatest at the lowest temperature jet cooking and decreases with increasing temperature. Usually in the same temperature range does not cross-linked starch has a significantly smaller change in the distribution of particles in size than the cross-linked starch.

These examples show the variation of the properties of starch in the range of cooking temperatures, and in particular, show changes in drainage and retention the project for a particle to changes in the temperatures of cooking.

1. Method for the production of paper comprising the following operations:

the starch component, which contains cationically crosslinked starch having a viscosity of hot pasta in the range of approximately from 10 to 3000 SP when measured on the Brookfield viscometer at a temperature of about 95°using spindle number 21 at 20 rpm, at a solids content of 2%;

b) cooking the first portion of the starch component to obtain a cooked starch component, and the specified cooking involves cooking the starch component at the first temperature boiling below 330°F (170° (C) during the first period of time;

C) dehydrating the composition of the paper, and the composition of the paper contains

(i) cellulose fibers in aqueous suspension,

(ii) microparticles, which contain at least 50 wt.% particles having an average particle size of not more than 1 μm, and

(iii) cooked starch component; and

g) adjusting the speed of dehydration due to the melting of the second portion of the starch component in the second medium-temperature cooking, which is at least 10°F from the first high temperature cooking.

2. The method according to claim 1, characterized in that the second medium temperature boiling range of 200 to 250°F (90 to 120°).

p> 3. The method according to claim 1, characterized in that the second medium cooking temperature is less than 230°F (110°C).

4. The method according to claim 1, characterized in that the microparticles are selected from the group comprising silica, clay, and combinations thereof.

5. The method according to claim 1, characterized in that it further provides for determination of the retention of particles and the temperature change to adjust retention of particles.

6. The method according to claim 1, wherein the starch component is cooked in a jet digester.

7. The method according to claim 1, characterized in that cationically cross-linked starch contains dent corn starch.

8. The method according to claim 6, in which the starch is cooked in a jet digester under pressure less than 150 psig (10.5 kg/cm2).

9. The method according to claim 1, in which the starch is introduced into the jet digester at a solids content from 1 to 10%.

10. The method according to claim 1, characterized in that the first average cooking temperature is from 180 to 330°F (80 to 170°).

11. Paper product manufactured by the method according to claim 1.

12. Method for the production of paper comprising the following operations:

the starch component, which contains cationically crosslinked starch having a viscosity of hot pasta in the range of approximately from 10 to 3000 SP when measured on a viscometer BRU the field at a temperature of about 95° With using spindle number 21 at 20 rpm, at a solids content of 2%;

b) cooking the first portion of the starch component to obtain a cooked starch component, and the specified cooking involves cooking the starch component at the first temperature boiling below 330°F (170° (C) during the first period of time;

C) dehydrating the composition of the paper, and the composition of the paper contains:

(i) cellulose fibers in aqueous suspension,

(ii) microparticles, which contain at least 50 wt.% particles having an average particle size of not more than 1 μm, and

(iii) cooked starch component; and

g) adjusting the first pass retention during dehydration due to the melting of the second portion of the starch component in the second medium-temperature cooking, which is at least 10°F from the first high temperature cooking.

13. The method according to item 12, wherein the second average cooking temperature is 200 to 250°F (90 to 120°).

14. The method according to item 12, wherein the second average cooking temperature is less than 230°F (110°).

15. The method according to item 12, wherein the microparticles are selected from the group comprising silica, clay, and combinations thereof.

16. The method according to item 12, characterized in that it further p is educative definition of retention of particles and the temperature change to adjust retention of particles.

17. The method according to item 12, wherein the starch component is cooked in a jet digester.

18. The method according to 17, characterized in that the starch is cooked in a jet digester under pressure less than 150 psig (10.5 kg/cm2).

19. The method according to 17, characterized in that the starch is introduced into the jet digester at a solids content from 1%to 3%.

20. The method according to item 12, wherein the first average cooking temperature is from 180 to 330°F (80 to 170°).

21. Paper product manufactured by the method according to item 12.



 

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The invention relates to aqueous compositions sizing agent and method for producing paper

FIELD: production of improved starch compositions and methods of use of improved starch compositions.

SUBSTANCE: proposed method includes use of starch component containing cationized cross-linked starch at viscosity of from 10 to 3000 cps. Production of paper includes the following stages: boiling the starch component at temperature of 165°C, dehydration of paper composition (paper fibers, inorganic filler, starch) and control of rate of dehydration and/or holding the first pass in the course of dehydration through change in temperature (by at least 10°C) of starch composition boiling.

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21 cl, 6 dwg, 2 tbl

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28 cl, 1 dwg, 5 tbl, 4 ex

FIELD: paper-and-pulp industry.

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3 tbl

FIELD: pulp and paper industry; methods of production of the pigment for manufacture of the cardboard and paper.

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2 tbl

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