SU1567710A1 - Method of manufacturing paper - Google Patents

Abstract

The invention relates to the pulp and paper industry and allows to intensify the process while maintaining the breaking strength of the paper. The method is carried out as follows. A suspension with a concentration of 0.2% is prepared from unmilled cellulose-containing fibers, and a short-fiber semi-finished product is added in an amount of 2-4% by weight of air-dry cellulose-containing fibers, and then the paper web is cast. As a short-fiber semi-finished product, a loose fibrous semi-finished product is used for the adsorbing layer of sanitary-hygienic products with a content of 5-100 µm 50-60% and water-retaining capacity of 1.8-2.0 g of water per 1 / g of fiber. The proposed method is used in the manufacture of tissue paper for sanitary and hygienic purposes. 1 tab.

Description

The invention relates to the pulp and paper industry and can be used in the manufacture of fine Oumag with "-shingen and hygienic designation, produced on pysokoskoros nine papermaking mint and increased strength.

The goal of the acquisition is to intensify the process while maintaining the equal strength of the paper.

The essence of the invention is that in cnocot e paper making, including

slurry of unground crushed 4eodes люл plots of their fibers and short EO.riOKfaicToro semi-finished product and pouring of paper web; with the content of the fraction of 5-100 microns 50-60% water-holding. with a capacity of 1.8-2.0 g iodine / g fiber with an osprey consumption of 2-4% by weight of air-dried cellulose fibers.

ate

ABOUT)

The use of an osprey to produce fluff fiber semi-finished product for an absorbent layer of sanitary-hygienic products in the proposed method allows to increase the rate of dehydration of the mass on the grid table and thus achieve an intensification of the paper making process.

Osprey is a mixture of fine fibrous elements that are separated from the fiber, mainly in weak areas (structural defects) under the influence of propping surfactants and mechanical shock in the process of fluffing a fibrous semi-finished product in a hammer mill.

According to electron microscopic study data, small fractions differ in noticeable surface fibrillation while maintaining 36–40% structural order. Due to the effect of surfactants, amorphization and particle destruction are minimized.

A suspension of unmilled cellulosic fibers with the addition of such fine fractions containing 50-60% of particles with sizes of 5-100 µm is relatively easy to dehydrate on the grid table. Particles with a size of less than 5 microns mostly go through the mesh into the circulating water.

Small fractions possess valuable binder properties: fibrillation of their surface promotes intensive bonding and an increase in the mechanical strength of paper.

For particles larger than 100 µm, a decrease in swelling capacity is observed as a result of an increase in their degree of crystallinity. Such particles are less effective as binders.

The method is carried out as follows.

From the unmilled cellulose-containing fibers (sulphite or sulphate pulp, wood pulp, thermo- and thermo-chemical-mechanical pulp), a suspension is prepared with the addition of an osprey of fluff fiber production for the absorbent layer of sanitary-hygienic products with a content of 5-100 µm 50- 60%

,

five

ABOUT

five

Q

0

and water retention capacity of 1.8-2.0 g of water / g of fiber. The consumption of the osprey is 2-4 by weight of air-dried cellulose-containing fibers. A paper web is cast from the prepared slurry.

Example 1 (experiments 1-4).

From unground fiber sulphate bleached hardwood pulp (13 SR) prepare a suspension concentration of 0.2%. A scopa of the production of fluff fiber semi-finished product is added to the suspension for an absorbent layer of diapers for children and hygiene packages with a content of 5-100 µm 49-61%, having a water retention capacity of 1.9 g water / g fiber, and the content of the osprey in suspension is 3% from the mass of air-dry fibers.

Then, castings are produced on the LOA-1 sheet-casting apparatus and their physico-mechanical parameters are determined by standard methods.

The dimensions of the small elements of plant cells are determined by a microscopic method.

Water holding capacity (MAS) of the osprey is assessed according to the following procedure.

A sample of the osprey (50 ml at a concentration of 0.6 g) is placed in a glass filter (Por. 100) and dehydrated at a fixed discharge and time to clot formation. The clot is weighed and dried for 18 hours, and again weighed, and the VLS is determined as the ratio of the mass of water in the clot to the mass of fibrous elements.

The rate of mass dehydration (cm / s) is determined by the flow rate of the filtrate (cm / s) through the unit area (cm2) at a constant discharge under the oil supply.

PRI me R 2 (experiments 5-8). Paper is prepared as described in Example 1, but an osprey production of fluffy fiber semi-finished product is added to the suspension for an absorbent layer of sanitary-hygienic products with a water-retaining capacity of 1.7; 1.8; 2.0; 2.1 g of water / g of fiber, and the fraction of 5-100 microns in the osprey is 55%.

PRI me R 3 (experiments 9-15). Paper is prepared as in Example 1, but an osp of the same production with a fraction of 5–100 µm 55% is added to the suspension, and the content of the osprey

five

in suspension, vary from 1 to 6% by weight of air-dry fiber. As a reference, I cast a sheet that does not contain an osprey.

PRI me R 4 (experiments 16-18). Paper is prepared analogously to example 1, but pine sulfate unbleached pulp fibers are used to prepare the suspension, and an oop of the same production with a content of 5-100 microns 55 is added to the suspension. The osprey content in the suspension is increased to 6% by weight of air-dry the fibers.

As a reference, an osprey-free sheet is cast.

Example 5 (experiments 19-20). Paper is made according to the method of the prototype. From unground fiber sulphate unbleached pulp () prepare the suspension concentration of 0.2%. The fines are added to the suspension, which is isolated from the same cellulosic fibers after their grinding rate (d). In the experiments using sieves with cell sizes of 100/200 mep

Content ext. The viscosity of the suspension is 3 and 6% of the air-dry fiber passes. At this, castings are obtained on a LOA-1 sheet-removal apparatus and their physical and mechanical parameters are determined by standard methods.

The results of these tests in examples 1-5, as well as data on the evaluation of the water retention capacity of the additive and the rate of dewatering of the mass are given in the table.

It can be seen from the table that in the proposed method the optimum content of the 5-OO fraction in the osprey is 50-60%. A decrease in the content of particles with sizes of 5–100 µm in an osprey with the properties of a binder leads to a decrease in the breaking strength of paper (example 1, experiment 3).

With an increase in the content of these particles in the osprey, the rate of dehydration of the mass (. Example 1, experiment 4) drops sharply as a result of more than the complete filling of micropores in the fiber layer, which has a high resistance to water filtration.

0

five

77

five

0 5

with

five

0

ten.

The optimal water retention capacity of the osprey is 1.8-2.0 g of water / g of fiber, as if the lower limit is exceeded (Example 2, Test 7), the tearing strength of the paper is reduced by reducing the hydrophilicity of the small fiber elements, and thus deteriorating their paper-forming properties.

When the upper limit is exceeded (example 2, test 8), the rate of dewatering of the mass decreases, since small fibrous elements with high hydrofluorization, it is difficult to give up water.

Claims (1)

The optimal consumption of the osprey, as blown from the table, is 2-4% of the weight of air-dry fibers, as when breaking the lower limit (Example 5, Test 13), the breaking strength of the paper decreases due to a decrease in the binder content. particles in the paper composition, and when vsods for the upper limit (example 3, experiments 14,15) decreases as the speed of dehydration of the mass due to an excess of small fibrous elements, which provide great filtration resistance, and rupture strength of paper, the structure of which becomes more rigid. Invention Formula A method for making paper, preferably for sanitary purposes and hygienic purposes, comprising preparing a fibrous suspension from non-dispersed cellulose-containing fibers and a short-fiber semi-finished product and tacking off a paper web, characterized in that, in order to intensify the process while maintaining the breaking strength of paper, a short-fiber semi-finished product is used to collect paper fluff fiber semi-finished product for the absorbent layer of sanitary-hygienic products with the content of the fraction is 5–100 µm 50–60% and the water-holding capacity of 1.8–2.0 g of water per 1 g of fiber with its consumption of 2–4% by weight of air-dry cellulose-containing fibers.