SU1726615A1 - Method of making paper - Google Patents

Abstract

The invention relates to the pulp and paper industry and allows for improved retention of fine fiber and filler while at the same time increasing mechanical strength and maintaining paper sizing. The method is carried out as follows. Prepare two masses. The first mass is prepared from a short-fibrous semi-finished product, ground to the required degree of grinding, filler, flocculant, and aluminum-containing coagulant. The second mass is prepared from milled long fiber semi-finished product, sizing agent and aluminum-containing coagulant. Then the masses are mixed and the paper web is cast. Sulfate hardwood pulp, waste paper or wood pulp, or their mixture, or mixture with an crowd at their ratio (10: 1) - (7: 1) is used as a short-fibrous semi-finished product. Sulfate or sulphite softwood pulp is used as a long-fiber semi-finished product. 1 hp f-ly, 1 tab. WITH S

Description

The invention relates to the pulp and paper industry and can be used in the production of various types of filled papers.

The purpose of the invention is to increase the retention of fine fiber and filler while simultaneously increasing the mechanical strength and maintaining the degree of sizing of the paper.

The essence of the invention is that in the method of making paper, including the separate grinding of short-fiber and long-fiber semi-finished products, the introduction of a sizing agent, the mixing of fibrous masses, the introduction of filler and the pouring of paper web, the filler is introduced into the fibrous mass of short-fibrous semi-finished product, and the sizing agent - in the pulp from the long-fiber semi-finished product before mixing the masses. At the same time as the short-fiber semi-finished product using sulphate hardwood pulp or waste paper, or wood pulp, or their mixture, as well as their mixture with an crowd in a ratio of 10: 1-7: 1.

Sulfate or sulphite coniferous cellulose is used as a long-fiber semi-finished product. The mixing of the fibrous masses is carried out with the ratio of the fibrous mass of the short-fiber semi-finished product and the mass of the single-fiber semi-finished product 1: 1-2.5: 1.

The method is carried out as follows.

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Two masses are prepared by preparing fibrous semi-finished products and introducing the necessary chemicals and filler: the first mass contains a short-fiber semi-finished product ground to the required degree of grinding, filler, flocculant (polyacrylamide) and aluminum-containing coagulant; the second mass contains a long-fiber semi-finished product ground to the required degree of grinding, a sizing agent and an aluminum-containing coagulant.

The first mass obtained is mixed and incubated for a certain time.

In the process of preparing the mass, the filler particles, including the osprey, are sorbed on the surface of cellulose fibers or waste paper, which become centers of aggregation of the particles. Introduced flocculating collects mineral-fibrous aggregates into larger structural units, and the introduction of aluminum salt allows AI ions to create strong aggregate units and give them a positive charge.

The prepared masses are fed through dispensers to the pool to obtain the finished paper pulp in a predetermined ratio, after mixing, it is diluted to the desired concentration and the finished pulp is fed to the net for emptying the paper web.

The proposed method makes it possible to more efficiently use basic and auxiliary materials, improve the quality characteristics of paper, and increase equipment productivity.

The obtained mineral-fibrous structural units of the paper pulp in the process of forming the web do not block the interfiber bonds of the main reinforcing element - cellulose fiber, but fill large interfiber spaces, since they do not migrate into the thin interfiber pores in the process of dewatering with suction.

The fibers of the short-fiber semi-finished product become the center of the aggregation of particles and act as a transporting agent for the fine particles of the kaolin and osprey suspension filler.

Paper is produced with an even gap and high mechanical strength due to the fact that structural aggregates charged with aluminum ions further enhance interfiber communications due to electrostatic interaction.

The productivity of the papermaking machine is increased, as large aggregates have a lower specific surface area compared to particles.

fine fibers and filler. Water retention is reduced. The dewatering process on the grid, presses and during drying is accelerated,

The proposed method is illustrated by the following examples.

EXAMPLE 1. The method is carried out by preparing two masses, then mixing them with a fiber ratio (wt.) Of 1: 1 and the casting of offset paper weighing 80 g / m2.

The first mass is prepared by grinding sulphate hardwood pulp to a grinding degree of 42-44 ° SR, introducing kaolin and aluminum sulphate.

The resulting mass contains the above components at their next ratio, wt.h .:

Short fiber semi-finished product100

Kaolin36,4

Aluminum Sulphate0.03

The second mass is prepared by grinding sulphite coniferous cellulose to a grinding degree of 30-32 ° ShR, adding rosin glue and aluminum sulphate. The resulting fibrous mass contains the above components at their next ratio, wt.h .:

Cellulose sulfite conifer 100

Rosin glue2,5

Aluminum Sulphate4.0

PRI mme R 2. The method is carried out by preparing two masses, then mixing them with a mass ratio of 2.5: 1 in fiber and casting of offset paper weighing 80 g / m2.

The first mass is prepared by grinding MS-1 and MS-2 waste paper (white without printing) to a grinding degree of 44-46 ° SH, adding an osprey to the resulting fibrous suspension in an amount that provides a 7: 1 ratio of waste paper, introducing kaolin and aluminum sulphate . The resulting mass contains the above components at their next ratio, wt.h .:

Short fiber semi-finished product100

Kaolin17,1

Aluminum Sulphate0.03

The second mass is prepared by grinding sulphate coniferous cellulose to a grinding degree of 34-36 ° SR, adding rosin glue and aluminum sulphate. The resulting mass contains the above components at their next ratio, wt.h .: Sulfate coniferous cellulose 100

Rosin glue2,5

Aluminum Sulphate4.0

Example The method is carried out by preparing two masses, then mixing them with a fiber ratio of 1.5: 1 and casting offset paper weighing 80 g / m2.

The first mass is prepared by grinding groundwood pulp to a grinding degree of 72-74 ° SHR, adding an osprey to the resulting fibrous suspension in an amount that provides a pulp: 10: 1 ratio, the introduction of kaolin and aluminum sulphate. The resulting mass contains the indicated components in a ratio according to Example 2 with the only difference that kaolin is taken in an amount of 24.6 parts by weight.

The second mass is prepared according to Example 1. EXAMPLE 4. The method is carried out by preparing two May, then mixing them with a mass ratio of 2.5: 1 in fiber and casting of 80 g / m2 offset paper.

The first mass is prepared by grinding sulphate hardwood pulp to grind 32-34 ° SR, grinding groundwood pulp to grind 66-70 ° SR, mixing them at a ratio of 1: 1, adding kaolin and aluminum sulphate to the resulting fibrous suspension.

The resulting mass contains these components in the following ratio, wt.h .:

Short fiber semi-finished product100

Kaolin25,6

Aluminum Sulphate0.03

The second mass is prepared according to Example 1. EXAMPLE 5. The method is carried out by preparing two masses, then mixing them with a mass ratio of 2.0: 1 in fiber and casting offset paper weighing 80 g / cm2.

The first mass is prepared by grinding sulphate hardwood pulp to a grinding degree of 34-36 ° SR, grinding MS-1 paper, their subsequent mixing at a ratio of cellulose: waste paper of 1: 2, adding to the resulting fibrous suspension of the osprey in an amount that provides the ratio of fiber: 8: 1 scop, injections of kaolin and aluminum sulphate. The resulting mass contains the following components in the following ratio, parts by weight:

Short fiber semi-finished product100

Kaolin12,6

Aluminum Sulphate0.03

The second mass is prepared according to example 1. PRI me R 6. The method is carried out as in example 1, but sulphate coniferous cellulose is used as a long-fiber semi-finished product for the 2nd mass, while grinding the short-fiber semi-finished product for the 1st mass is carried out degrees of grinding 32-34 ° ShR, and grinding a long-fiber semi-finished product for the 2nd mass - to the degree of grinding 30-32 ° Sh R.

Example (prototype). The method is carried out by preparing two masses, their subsequent mixing at a fiber mass ratio of 1: 1, introducing a filler (13.1% by weight of fiber) and osprey (8% by weight of fiber) and pouring offset paper weighing 80 g / m2.

The first mass is prepared by grinding sulphate hardwood pulp to 32-34 ° ShR, introducing rosin glue and aluminum-containing coagulant. The resulting fibrous suspension contains these components at their next ratio, parts by weight:

Sulphate pulp cellulose 100

Rosin glue2,3

Aluminum Sulphate4,5

The second mass is prepared by grinding sulphate bleached softwood pulp to a grinding degree of 30-32 ° SH.

The quality of the paper obtained in examples 1-7 are shown in the table.

As can be seen from the data in the table, the proposed method allows to obtain paper characterized by increased fracture and tear strength, stable sizing and high retention of the filler and fine fiber.

Claims (2)

Invention Formula 1, a method for making paper, comprising separately grinding short fiber and long fiber semi-finished products, introducing a sizing agent, blending fibrous masses, introducing a filler and pouring a paper web, characterized in that, in order to increase the retention of fine fiber and filler while simultaneously increasing mechanical strength and maintaining the degree paper sizing, the filler is introduced into the pulp from the short-fiber semi-finished product, and the sizing agent is in the pulp from the long fiber th semifinished mass before mixing. 2. The method according to claim 1, characterized in that as a short fiber semi-finished products use sulfate hardwood pulp, or waste paper, or wood pulp, or their mixture, or a mixture with an ensemble at a ratio of from 10: 1 to 7: 1. Note e. Paper is offset, the weight and paper are sampled simultaneously with the speed of the paper machine.