Method of preparation of paper pulp

 

(57) Abstract:

The method relates to the preparation of paper pulp in the production of printing the book and magazine paper using a modified aluminium sulphate (coagulant) and water-soluble synthetic polymers and co-polymers as flocculants. Prepare a water-fibrous dispersion of cellulose fibers. Its fill and glue resin glue. Then neutralize the paper weight of aluminium sulphate - coagulant pre-mixed with a cationic polyelectrolyte VPK-402 to a pH of 6.0 to 6.5. Sodium hydroxide pH adjusted to 7 - 8. Then precipitated coagulant and flocculant. As a last use polysulfonamide MM 2500 - 3000, a copolymer of methacrylamide with the ammonium salt of methacrylic acid MM 10000 - 100000 copolymer of piperylene methacrylic acid 10000 MM and a copolymer of piperylene with Acrylonitrile 1000 MM. The technical result consists in increasing the efficiency of paper production, increase the degree of retention of paper pulp, the improvement of physical and mechanical properties of paper and reduction of wood consumption per unit of production. 1 C.p. f-crystals, 1 table.

The invention relates to pulp and paper Promyshlenny efficiency of the process.

Known method of preparing paper pulp through the introduction of polyacrylamide in the suspension of pulp in suspension of the filler, followed by mixing them and prepare a paper on listonline apparatus.with. The USSR 787535, class D 21 H 3/66, op. 80).

Closest to the claimed invention is a method for preparing paper pulp, comprising the preparation of an aqueous fiber dispersion, filling, sizing and sedimentation with coagulant and flocculant, used as a coagulant aluminum sulfate, and as a flocculant polyacrylamide (Ivanov, S. N. Technology paper. From "Forest industry", M, 1970, S. 140, 141, 189, 192, 195, 233-235, 238, 239-242).

The disadvantages of this method include the use of expensive imported flocculant is polyacrylamide, low degree of retention of paper pulp, not sufficiently high physical-mechanical properties of paper.

From a large number of organic polymers, synthesized both in Russia and abroad, which is a potential auxiliary additives in the manufacture of paper, have been studied as flocculants limited number of them. The results of the use of cationic and anionic polial the different publications. Monomeric structure and functional composition of the polyelectrolytes are not published.

One of the main disadvantages of using synthetic adhesives in the production of securities (such as "Aquapel", FIBRAN" and others) is a low degree of retention of kaolin, because the adhesive is deposited only on the fibrous material. In addition, when using additives cationic stabilizing substances. These disadvantages deprived of rosin size, the use of which in the neutral-alkaline environments is of great practical importance. However, if the paper weight of aluminum sulfate sizing runs unsatisfactory due to a sharp reduction in the magnitude of the surface charge of the dispersed phase and the subsequent recharge. To improve the sizing should be excluded reload the surface of the paper pulp.

The total surface charge of the dispersed phase dispersions of fibrous wood material and filler has the greatest influence on the strength of coupling between the individual fibers and filler particles and, consequently, the degree of retention of weight and physico-mechanical properties of paper. Found that water-soluble synthetic polymers and sobornost charge of the dispersed phase of the dispersion of pulp and in the presence of aluminum sulfate.

The objective of the invention is to develop a method of making paper pulp, allowing to increase the degree of retention of paper pulp, to improve the physical and chemical characteristics due to the use of new domestic water-soluble polymers and copolymers as a flocculant, a modified aluminum sulfate and rosin glue on stage sizing that will reduce the cost of technology of paper production and improve product quality.

This is the technical result, which is in causal connection with the essential features.

The essential features of the invention: preparation of an aqueous fiber dispersion, filling, gluing resin adhesive at the rate of 12 kg/T, neutralization of mass modified with aluminum sulfate to pH 6,0-6,5, processing it with sodium hydroxide to pH 7-8 and the subsequent introduction of the flocculant: modification of aluminum sulfate is carried out by mixing it with a cationic polyelectrolyte VPK-402, as flocculant used water-soluble synthetic organic polymers and copolymers containing amide, carboxyl, sulfonic or nitrile group, can due to the adsorption of macromolecules dispersnoi phase, to enhance the flocculation of paper pulp, thereby increasing the degree of retention of paper pulp on a grid-style PM.

The method is as follows: water-fibrous mass is added to the kaolin, rosin size, is the neutralization of mass modified with aluminum sulfate to pH 6,0-6,5, after which the pH was adjusted to 7-8 with sodium hydroxide, then enter the flocculant; modification of aluminum sulfate spend processing cationic polyelectrolyte VPK-402, VPK-402 - polydimethyldiallylammonium water-soluble cationic polyelectrolyte, technical conditions TU 6-05-2009-86, appearance and physical-chemical parameters meet the requirements and safety standards.

As the flocculant used is a water-soluble synthetic polymers and copolymers containing amide, carboxyl, sulfonic or nitrile group, can due to the adsorption of macromolecules of polymers and copolymers of the fibers and filler particles to modify the surface charge of the dispersed phase, to modify the structure of the dispersion of paper pulp, to enhance flocculation by increasing the electrostatic component of the interaction forces. The flocculant consumption sastavljam 2500-3000 (KK-1) structural formula

< / BR>
where n is the number of monomers in a macromolecule polymer,

as a copolymer containing amide group, use methacrylamide with the ammonium salt of methacrylic acid MM 10000-100000 (ACS-2) structural formula

< / BR>
where m is the number of monomers of the first composition in the macromolecule copolymer, n is the number of monomers of the second composition in the macromolecule copolymer;

as the polymer containing a nitrile group and a double bond is used, the copolymer of piperylene with Acrylonitrile MM-10000(QC - 3) structural formula

< / BR>
where n is the number of monomers in a macromolecule polymer,

as the polymer containing a carboxyl group and having a double bond, is used a copolymer of piperylene methacrylic acid 10000 MM (ck-4) structural formulas.

< / BR>
where n is the number of monomers in the macromolecule copolymer.

Castings were prepared listonline apparatus LA-2 (Central laboratory of JSC "Syktyvkar LPK"). Determination of physico-mechanical properties were carried out according to GOST 13525. 1-79, STSM 2426-80, GOST 7690-66.

Example 1 (control): preparing the water-fiber suspension containing 35% softwood bleached pulp, 50% hardwood bleached aim with the use of synthetic glue "Aquapel"; neutralization of mass is modified with aluminum sulfate to pH 6,0-6,5 (modified coagulant); sodium hydroxide pH is brought mass 7-8; introduces the flocculant is polyacrylamide at a flow rate of 300 g/So

Modification of sulfate of aluminum is that aluminum sulfate is pre-mixed with a cationic polyelectrolyte VPK-402 at a flow rate of 100 g/So

Results: retention 56,0%, breaking length - 3560 m, sizing - 1.2 mm, ash content of paper - 8.4%, and the opacity to 96.9%.

Example 2: preparing paper pulp as in example 1, but under sizing is added console glue, and as a flocculant instead of polyacrylamide used water-soluble synthetic polymer - polysulfonamide (KK-1). Results: retention was 65.3% breaking length - 4820 m, sizing is 1.2 mm, the ash content of the paper was 8.8%, opacity - 97,2%.

Example 3: preparing paper pulp from example 1, stage sizing is added rosin size, and as a flocculant used is a copolymer of methacrylamide with the ammonium salt of methacrylic acid (KK-2). Results: retention - 52,7%, breaking length - 493 m, sizing - 1.2 mm, ash content was 7.9%, the opacity to 96.9 %.

Example 5: preparing paper pulp from example 1, stage sizing is added rosin size, and as a flocculant is a copolymer of piperylene methacrylic acid (ACS-4). Results: retention was 59.9%, breaking length - 4570 m, sizing - 1.2 mm, ash content, and 9.0 %, the opacity of 97.3%.

As follows from the presented data (see table), neutralization of paper pulp modified with aluminum sulfate (coagulant), rosin sizing glue and application of water-soluble synthetic polymers and copolymers of polysulfonamide, methacrylamide with the ammonium salt of methacrylic acid, copolymer of piperylene with Acrylonitrile and a copolymer of piperylene with methacrylic acid as a flocculant comprising paper pulp in paper production, owing to a strengthening of the forces of interaction between the components of paper pulp to increase the degree of restraint on 7-17 %, to improve the quality indicator paper "breaking length" 3-36%, increase retention of kaolin in some cases, 12%, significantly reduce the consumption of wood per unit reconaisance requirements.

1. Method of preparation of paper pulp, comprising the preparation of an aqueous fiber dispersion, filling, sizing rosin glue and sedimentation with coagulant and flocculant, wherein after the sizing exercise neutralization of paper pulp by the sulphate of aluminium, pre-mixed with a cationic polyelectrolyte VPK-402 - polydimethyldiallylammonium to pH 6,0 - 6,5, and sodium hydroxide pH adjusted to 7 - 8, the sizing is carried out at the expense of the rosin glue 12 kg/t, and as a flocculant use synthetic water-soluble organic polymers and copolymers containing sulfonic, carboxyl, amide or nitrile group, can due to adsorption of macromolecules of polymers and copolymers of the fibers and filler particles to enhance flocculation and increase the degree of retention of paper pulp, as a polymer containing a sulfonic group, use polysulfonamide MM 2500 - 3000 (KK-1) structural formula

< / BR>
where n is the number of monomers in a macromolecule polymer,

as the polymer containing carboxyl and amide group, use the copolymer methacrylamide with the ammonium salt of methacrylic measure,

as the polymer containing a nitrile group and a double bond, use a copolymer of piperylene with Acrylonitrile 1000 MM (ck-3) structural formula

< / BR>
where n is the number of monomers in a macromolecule polymer,

as the polymer containing a carboxyl group and a double bond, use a copolymer of piperylene methacrylic acid 10000 MM (ck-4) structural formula

< / BR>
n is the number of monomers in the macromolecule copolymer.

2. The method according to p. 1, wherein the flocculant consumption is 0.3 kg/T.

 

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