SU836264A1 - Method of preparing pulp for making electric insulation paper - Google Patents

Description

The invention relates to the pulp and paper industry, in particular, to a technological scheme for the grinding of pulp from a mixture of cellulose and synthetic fibers, intended for the manufacture of electrical insulation paper. A known method for the preparation of pulp for the manufacture of cable paper from cellulose and synthetic fibers, according to which the grinding of fibers is carried out together to 60-75 ° SR, in order to improve the dielectric properties of paper l. . Such joint grinding can be carried out in a roll machine, where the mass passes all the stages necessary for the development of the fiber: pre-grinding, swelling and grinding. However, the operation of a roll is a large expenditure of electricity, periodic operation and, most importantly, the duration of the process of grinding. For modern industrial enterprises that have switched to a continuous method of mass preparation, this method is unacceptable. When using cellulose and synthetic fibers of disk mills for joint grinding, the fibers are peeled off and the living section of the grinding set is clogged, as a result of which the mass flow through the mill decreases or stops altogether. The grinding process becomes unstable, and the specific energy consumption increases aetc. If, however, the cutting length is reduced or the mass concentration is reduced to avoid clogging and to preserve the mill throughput, this will lead to a deterioration in the paper trait quality and physical and mechanical properties of the paper. The purpose of the invention is to intensify the process and reduce the specific energy consumption. The goal is achieved by the fact that in the method of preparing pulp for the manufacture of electrically insulating paper, including mixing synthetic and cellulose fibers and grinding the resulting pulp, in accordance with the invention, before mixing, synthetic fibers with a concentration of 3-5% pass through at least one time open output and the gap between the disks of 0.05-0.15 mm, and

Cellulose fiber is pre-ground to 30-70 SR, while grinding the pulp to 93-96f SR.

Example. Polyethylene terephthalate (lavsan) staple fiber is passed through an open-exit disk mill with simultaneous addition of water in such an amount that the exit mass is 3-5% with a gap between grinding disks 0.05-0.15 mm

Sulfate pulp brand E-1 is ground in a mill, with a closed output with a specific load on

LJn-i J l

the edges of the knives 1200-1300 in text

4 minutes to the degree of grinding 64 SR and a mass indicator of the length of the fiber 3 dg at a mass concentration of 2-2.5%.

Then the composition of the fibrous mass in the ratio of - 25% synthetic polyethylene terephthalate fiber and 75% sulphate pulp E-1 is made, these fibers are mixed in such a way that the mixture concentration is 2%, and grind in a disk mill with a closed exit at a specific . Load 740-800 2 for 10 Min.

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At the same time receive the degree of grinding and mass index of fiber length 41 dg.

Comparative data proposed and known method are given in the table.

Claims (1)

Claim A method of preparing pulp for the manufacture of electrical insulating paper, comprising mixing synthetic and cellulosic fibers and grinding half. fibrous pulp, characterized in that, in order to intensify the process and reduce the specific energy consumption, synthetic fibers with a concentration of 3-5% are passed at least once through a disk mill with an open outlet and a gap between the disks 0 before mixing , 05-0.15 mm, and the cellulose fiber is preliminarily milled to 30-70 ° SR, while the pulp is milled to 93-96 SR.