SU1500934A1 - Method of determining the criterion of susceptibility of paper mass to sizing - Google Patents

Abstract

The invention relates to the production of paper, in particular, to the determination of the degree of sizing of paper, and allows to increase the reliability of the degree of sizing according to the found criterion of susceptibility of paper pulp to sizing. The purpose of the invention is to increase the reliability of determining the degree of sizing. A suspension of fiber semi-finished product is prepared, glued with rosin glue in the presence of aluminum sulphate to form an alumina complex in the resulting paper pulp, then the amount of alumina complex deposited on the short and long fiber suspension is measured, and the total amount of this complex, the proportion of fine fiber in the paper pulp and the degree of its failure, and according to the data obtained, the susceptibility criterion is determined by calculation. 1 tab.

Description

The invention relates to methods for determining the degree of sizing paper and can be used in the pulp and paper industry in the production of adhesive types of paper and cardboard.

The aim of the invention is to increase the reliability of the determination of the degree of sizing according to the found susceptibility criterion.

The method for determining the susceptibility criterion of paper pulp for sizing involves preparing a slurry of a semi-finished fiber, sizing a fibrous suspension with rosin glue in the presence of aluminum sulphate to form an alumina complex, measuring the structural and mechanical properties of the pulp and determining the susceptibility criteria using it, while the amount of aluminosmols is measured in the suspension complex, deposited on a short and long fiber and the total number of the specified complex, and its structural-mechanical Twa, which is used as a small fraction of fibers in the pulp and the degree of failure is measured after sizing istoy fiber mass and calculated from the data obtained by finding m susceptibility test.

The criterion of susceptibility of paper pulp to sizing is determined by the following formula

Go to l-A4-Yj (l-o) A + of 5- Y ,, (l)

about

with so

where Y, is the degree of heteroadgulation of the alumino-resin of the complex with the fiber, the calculated value, and is determined as follows: the total amount of the alt-resin complex on the fiber

V -

The amount of the alumina complex in the paper pulp can be determined indirectly by the value of the potential of the particles of the sludge of the alumina complex

Y, -, 1

where if. - potential of sediment particles in the alumino-complex with i-OM set of values of technological parameters;

one

. MOX

- normalized multiplier satisfying the condition

0 -. ,,, l,

 - the degree of failure of the fine fiber, the calculated value, defined as follows

Y-2 A. A,

oi d

 amount of short fiber in the subgrid water

the amount of fiber in the fiber suspension is the relative adsorption index, the calculated value and is determined by the formula the amount of the alumina complex retained

mass unit short fiber

the amount of a complex of the retained

unit mass of long fiber

proportion of long fiber in fiber suspension, calculated

value and is determined by the formula

the amount of fiber remaining on the mesh at

this dehydration mode

total fiber in fiber suspension

Determining the variable Y j P for various values of technological parameters for a given fibrous half-life}) abricate and calculating the value of the Krrr criterion using the above formula, determining such values of the technological parameters at which the value of the criterion K goc takes on the greatest value. Kgpc criterion change range

 The implementation of 1 and the proposed method for determining the criteria for susceptibility of paper pulp to sizing allows one to determine the optimal conditions for applying sizing substances under laboratory conditions without obtaining finished paper, which significantly reduces the time for determination of various combinations of ingredients used, paper pulp at different reflux modes. Example 1. Grade A-1 bleached pulp is crushed to, 500 ml of a suspension of fibrous semi-finished product prepared (fibrin / ISKX

the suspension, at a concentration of 0.5%, is determined on the cell for dynamic retention during dewatering on a No. 46 / 12.5 x 2 grid with a stirrer speed of 1400 rpm

ci - 0.48,

then in 500 ml of fiber suspension with a concentration of 0.5%, rosin glue is introduced in an amount of 2% by weight of a.s. fibers, and sulfuric acid aluminum to pH 4.5. The sample prepared in this way on a cell for dynamic retention is divided into 2 fractions: a suspension of short fiber and a suspension of long fiber. Acid-alcohol extraction of rosin from both fractions is then carried out and A

A 0.0019

20,

For the determination of Y, take I ml of rosin glue konient1) by the action of 20 g / l.

diluted in i00 ml of distilled water, injected coagulant to a pH of 4.5 and the concentration of aluminum compounds Cif 30 -10 g-ion / l, and the potential of the particles of the glue precipitate formed is measured.

The value determined in preliminary studies is 27 mV

Y

 VMOIKC To determine Y

0.678.

- 500 ml of a 0.5% fibrous suspension is prepared, aluminum sulphate is added to a pH of 4.5, and the concentration of aluminum compounds is C g O x X 10 g-ion / l. On a cell for dynamic hold with the same

the net and the number of revolutions of the agitator, as in the determination of (, dewater the resulting paper mass, and determine the amount of fine fiber in the subgrid water and then

Ya

C / w 0.33 p 40 - -7 U, 1 j, C her-i. B

Substitute the obtained values with (, A

Y, Y. in the formula (1), find the values of the criterion of the degree of sizing K. 0,51.

From this paper pulp, a solid web is cast and its properties are determined, including the degree of sizing.

StP 1.25.

The technological parameters, which are reflected in the coefficients Y, and Y, change, namely the pH value during the formation of glue sediment is 4.0, and the pH at low tide is 4.3, the concentration of aluminum compounds at low tide is 12 g-ion / l.

Similarly to that described by calculation, Y and Y are determined.

  19.8

 Max

21

 0.735;

- C "b 128

 R

bs

2.5

 0.131;

bs 0.55.

Nz of the bulk obtained is a paper web cast and its properties are determined, including the degree of sizing of the ST .J1.40.

At pH during the formation of glue sediment, equal to 5.0; pH value at low tide equal to 5, the concentration of aluminum compounds at low tide C 6 x

X 10-g-ion / l Y, 0,558; Y, 0.134; Bose, The degree of sizing of the paper obtained from this pulp is STP, 0.75.

Analysis of experimental data

shows a good agreement between the change in the degree of sizing and the value of the susceptibility criterion of paper pulp for sizing (the correlation coefficient is 0.91).

Example 2. Unbleached sulphate pulp is ground to 36 HR, 500 ml of a 0.5% fiber suspension is prepared, determined on a cell for dynamic retention.

when dewatering on the grid No. 46 / 125x X 2 with a stirrer speed of 1400 rpm.

w

thirty

. B | about"

Then, in a 500 ml fibrous suspension with a concentration of 0.5%, rosin glue is introduced in an amount of 2% by weight, as well. fiber and aluminum sulphate to pH 4.5. The suspension prepared in this way in a cell for dynamic retention is divided into two fractions: a short fiber suspension and a long fiber suspension. Acid-alcohol extraction of rosin from both fractions is then carried out and A d

45

BUT - . A 0,0026

To determine Y., take I ml of rosin glue with a concentration of 20 g / l, dilute it in 100 ml of distilled water, inject coagulant to pH 4.0 and the concentration of the compounds aluminum Sdr - 3 "Yu-g / l and measure - potential of particles of the formed glue deposit

Y,

- 26.4

27

 0.976.

7150

Prepare 500 ml

To determine the fibrous suspension i at a concentration of 0.5%, aluminum sulphate is introduced to a pH of 4.0, while the concentration5 of aluminum compounds is 1: 1 g-ion / l. On the cell for dynamic retention with the same mesh and the number of revolutions, as in Example 1, dewater the paper pulp and determine the amount of fine fiber in the subgrid water and then

the finished Sample paper cast from the mass of Example 2 is 1.60.

Thus, the proposed method for determining the criteria for the susceptibility of the booming mass to the sizing of the factors of the sizing process allows determining the optimal conditions for holding the sizing of paper and more reliably predicting the expected degree of sizing of the finished paper.

Claims (1)

Invention Formula The method for determining the criteria for the pulp strength for sizing, including the preparation of a suspension of fibrous semi-finished product, sizing of the suspension with rosin glue in the presence of aluminum sulphate I Compiled by WITH. / willow the sun but 2.5 Substitute the obtained values ai. l one Yj in formula (1), are BUT the value of the susceptibility criterion K weight is 0.70. According to the curve characterizing the dependence of K and StP, the degree of sizing of paper of Stp 1.75 is determined. The table shows the results of research. The measurement of the structural and mechanical properties of the mass and the determination of its susceptibility criteria, characterized in that, in order to increase the accuracy of determining the degree of paper sizing according to the susceptibility criterion found, the amount of the alumina complex settled on a short and long fiber is measured. suspensions, and the total amount of the specified complex, and the structural-mechanical properties are measured after the gluing of the suspension, while using structural and mechanical properties t fine fiber share in the pulp and the degree of the failure and receipt (m data determined by calculation criterion susceptibility. Cl pin