SU1033617A1 - Method for making electrically insulating paper - Google Patents

Description

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SP) The invention relates to paper and paper industry, in particular, to the production of electrical insulating paper with active filler and more specifically to capacitor paper, containing natural aluminosilicates as the active filler, and i it is papyhorskite or its natural mixture with montmorillonite, From the conditions of the use of primed aluminosilicates as an active filler in paper dielectric, IL is the preliminary purification of impurities of Na and K ions, which cause dielectric growth, paper dielectric sweat , It is known to manufacture paper con capacitor bank using as a filler natural aluminosilicate which is introduced before. It is treated with polyvalent metal salts for the replacement of alkali metal ions. discharging the deterioration of it in paper by ions of trivalent or divalent metals 11. However, during the ion-exchange substitution reaction in aluminosilicate suspension, the displaced ions remain in the liquid phase of the system and such a suspension is introduced directly into the pulp to increase the dielectric loss of the paper dielectric. to be isolated and, ideally, to remove it with deionized water, which makes the whole process economically unprofitable, as a result of which the spa has found industrial use. The closest to the invention to the technical essence and the achieved effect is a method of making electrically insulating paper, which includes preparation of paper pulp, preparation of natural aluminosilicate, processing it with ion exchange resins on a mixed-use filter containing a mixture of cationic and anion-exchange resins, introducing a purified suspension S the paper mass and the flow of the paper web. Purification of a natural aluminosilicate suspension using ion exchange resins allows maximum purification of it from Na and K Hz ions. A disadvantage of the known method is that ion exchange resin filters need to be periodically regenerated with a postgut rinse with deionized water, since during the operation the resin loses exchange capacity. In addition, a suspension of natural algo-silicate prepared with deionized water (and in the production of capacitor paper this is a necessary condition .- |, is characterized by low stability over time. The aluminosilicate particles quickly precipitate and cover the surface of ion-exchange resins. frequent loosening of the filters and washing them with deionized water from the sediment layer. This complicates and increases the cost of the process and the paper made in accordance with this process. simplifying the process by eliminating the sorbent cleaning operation while maintaining the paper quality indicators. The goal is achieved by the method of manufacturing electrically insulating paper, including preparing paper pulp, preparing a natural aluminosilicate slurry, introducing the latter into paper pulp and pouring the paper web provides for introducing a suspension into the pulp natural aluminosilicate with a particle size of 0.5-1 μm 60-90% and a viscosity of 1.8-2.5 cSt. The use of such a suspension makes it possible to obtain oxide paper without prior purification of sorbite from ionic impurities. This is explained by the fact that the more the clay particles are crushed, the more ml is introduced into the solution of electrolyte impurities and associated organic matter due to the more complete opening of the surface of the crystals. In addition, an increase in the suspension of the content of Na and KG in the filtrate is influenced by the more free access of water molecules to. the surface of the crystal lattice of the clay mineral and the formation of water bonds instead of bonds with Na and K. All impurities (electrolytes, organics, and exchange products) are transferred to the aqueous medium of suspensions. Addition of a suspension of natural silicate - palygorskite with a viscosity of 1.9 cSt at a concentration of 3 , 5% and a particle size of 0.5-1 µm in the amount of 90% introduces 0.04 mg / l of sodium ions into the paper mass, - A suspension with a viscosity of 1.49 sS of 3.5% and a size of 3.5% prepared particles of 5 microns (50% | and added in the same amount in romazh At the same time, the smaller the suspension of the natural sorbent contains asters 0.5–1.0 µm in size (less than 60%, the less soluble salts and organics enter the mass of the sorbent. In this case the sorbent preserves more Na and K ions, which then remain in the boom & Te at its ebb and do not leave with waste water on a papermaking machine. EXAMPLE 1 Take pulp, ground on a continuous grinding plant, diluted to a concentration of 0.25%. The weight of the paper mass is dewatered on a vacuum-suction device (eg, a leaf-cutting apparatus) (. In the filtrate, the content of Na ions (mg / l), which is 0.04 mg / l., Is determined. e p 2, Preparing a palygorskite suspension with the following compounds and parameters and parameters Concentration,% 2 Viscosity, cSt1.8 Amount of particles 1 µm in size,% 90 T yellow impurities (sand, stones and T.-nj) are removed by settling To remove the BSBettte Htajx impurities, mainly of plant origin, suqaeH3K is passed through a% 0 voATft set cell with a cell size of 0.03: 3-0.010 mlA Iodine prepared 5% by weight of abs. dry fiber, the pulp is dehydrated, and in the filtrate, it is determined to contain 1+ ions). Contents of istes Into flash (0.08 mg / l was consumed. Frozen. Prepared suspension of palygorskite with the following notes EXAMPLE 4 A palygorskite suspension was prepared with the following parameters: Concentration,% 4.0 Viscosity, cSt2.5 The number of particles 0.5–1 µm in size,% 60. Further - as in Example 2. Ion Containment Na in the filtrate - 0.13 mg / l. EXAMPLE 5 A palygorskite suspension is prepared with the following parameters: Concentration,% 2.0 Viscosity, cSt1.46 Quantity. in particles with a size of 5 μm,% Up to 75 Dalayayu-act, as described in example 2. The content of Na ions in the filtrate is 0.05 mg / l. Iodine suspension is metered into pulp, ground and. purified according to the traditional pattern. The amount of filler injected is determined by the required ash content, and, for example, the paper death of the ANKON is 5% by weight of abs. dry fiber. The table presents the results of tests of paper dielectric, a-. proposed and known methods. A comparative analysis of the data presented in the table shows that the 4: cijdr value of the paper dielectric remains at the level of the paper obtained by the known method, while the production costs for its manufacture are significantly reduced.

Paper dielectric (paper ANKON) j in dry form,% y at 4.

Paper dielectric L paper ANKON 1-12) in the form impregnated with TCD in sections,%. at ft

Ash content

0.14-0.16

0.14

0.26-0.27

0.26-0.27 2.1 2.4 j103 The proposed method for the manufacture of electrically insulating paper with an active filler in comparison with the known, for example, compared with the technology of manufacturing capacitor paper using as a rule the active filler of synthetic sorbents, reduces the cost of 1 ton paper for 17 495 rubles. Based on the annual demand of the national economy in paper with active filler of 2.0 thousand in savings, it will be 99.0 thousand rubles. The invention also allows refusing supplies for the import of synthetic sorbent, which is still used in the technology of paper production with active filler.

Claims (1)

15 4> 15 7) METHOD FOR MANUFACTURING ELECTRIC INSULATION PAPER, including preparation of paper pulp, preparation of a suspension of natural aluminosilicate, introduction of the latter into the paper pulp and casting of paper web, so as to ensure simplification of the process by eliminating the operation of cleaning the sorbent while maintaining quality indicators paper, a suspension of natural aluminum silicate with a particle content of 0.5-1 micron 60-90% and a viscosity of 1.8-2.5 cSt is introduced into the pulp.