CS276614B6 - A method of producing pulp from waste paper with a high wood content - Google Patents

Abstract

The solution falls into the field of pulp and paper industry. It solves a method of utilizing waste paper with a high content of woody podials into pulps with improved strength properties, usable for the production of paper products of a better quality class. The procedure is that the waste paper is treated with 2.5 to 20% by weight of hydrogen peroxide or sodium percarbonate with the simultaneous addition of sodium hydroxide in an amount corresponding to an alkaline environment with a pH above 3, at a temperature of 50 to 100 °C at atmospheric pressure, at a hydromodulus of 1: 8 to 1: 5 with mixing. The method can be used in the production of cardboard, corrugated cardboard, etc.

Description

The invention relates to a process for the production of pulps from recovered paper with a high content of woody fractions. It can be used in the pulp and paper industry.

Corps paper with a high content of lignified fibers, such as newspapers, some types of magazines, brochures, telephone directories, books and the like, is currently processed in the world and in our country almost exclusively by lightening, ie by removing printing inks. However, the resulting pulp is only suitable for paper products on which increased requirements for strength properties are imposed.

The production of pulps from recovered paper with improved strength properties using sulfur or chlorine compounds is the subject of MS. author's certificate no. 248 451 AO 272 485. However, these inventions do not cover all available and effective agents. The main disadvantage of the current method according to Czechoslovakia. author's certificate no. 243 451 and AO 272 485 is the use of sulfur and chlorine compounds in the processing of recovered paper, which adversely affects the environment.

This disadvantage is eliminated by the invention, the essence of which consists in that the recovered paper with a high content of wood fractions is treated with hydrogen peroxide or sodium percarbonate in an amount of from 2.5 to 40% by weight, based on the weight of the recovered paper. sodium in an amount corresponding to a pH of more than 6, at a temperature of G0 to 100 ° C, at a hydromodule (ratio of waste paper and fractional solution) of 1: 3 to 1: 6 for 1 to 3 hours with stirring without pressure.

In this process, untreated triode paper that does not contain sulfate is treated with hydrogen peroxide. The ink is partly released by the action of the alkali and thus leaves in the liquid leachate to the regeneration boiler, where it burns and partly disperses in the pulp.

The main advantage of the new process is the elimination of sulfur and chlorine compounds during processing, which considerably improves the work and the environment and reduces the corrosion of the equipment.

Example i:

525 parts by weight of an aqueous solution containing 33.3 parts by weight of 33% ^H 2 ^C 2 ^and parts by weight of LiOH are added to 100 parts by weight of waste paper. The mixture was heated at 50 ° C for 3 hours with stirring. After washing, a small amount of sodium sulphite solution is added to give a product with a yield of 90% based on the waste paper charge, a market length of 3.9 km (original market length 2.3 km) and a yield at a pressure of 120 kPa. .

Example 2

As in Example 1, except that sodium percarbonate was used in an amount of C5.3 parts by weight and NaOH in an amount of 5.12 parts by weight instead of hydrogen peroxide. The mixture is heated without pressure with stirring at 100 DEG C. for 1 hour. Pulp is obtained in a yield of 73% based on the waste paper feed, with a market length of 3.9 km and a feed of L'on at a pressure of 140 kPa. .......

*! 5 275614 D2

The method according to the invention makes it possible to achieve increases in the values of mechanical strengths while at the same time improving the optical properties in the process of processing corrugated paper with a high content of woody components. The resulting product is thus usable in the production of quality paper products.

The use of these reagents is. It is also advantageous in that the liquid wastes from this process are recyclable and can be rounded off, for example, into sulphate regeneration.

The main effect of the invention is that it makes it possible to increase the mechanical properties of the final product from 2 to 2.3 km to 3.9 km.

Claims (1)

G 27GG14 D2 The method of the present invention makes it possible to achieve a high level of mechanical strength by enhancing optical properties in the processing of recovered paper with high wood content. The resulting product is thus usable in the production of quality paper products. The use of these agents is also advantageous in that the liquid wastes from this process are recirculable and can be rounded, for example, to sulfate re-centrifugation. The inventive effect of the invention is that it allows the mechanical properties of the resulting product to be increased from 2 to 2.3 km to 3.3 km. P Λ I E I! A method for producing pulp with a high wood content paper stock characterized in that it is treated with the aqueous solution of hydrogen peroxide, but sodium percarbonate in an amount of from 2.5 to 20% by weight based on the weight of the paper stock. with the addition of sodium hydroxide in an amount corresponding to ρ; Ι above the value of 8, with the warming of GO up to 100 ° C at atmospheric pressure with stirring for 1-3 hours, with the hydromodule 1: 8 to 1: G.