Method for beating pulp

Abstract

In a first invention, there is provided a method for preventing damage to pulp fibers and internal fibrillation in a pulp production process to regulate the freeness, whereby, on the same freeness level as mechanical treatment, more stiff and bulky pulp can be produced and the bulky level of paper as the product can be improved. In a second invention, in the treatment of process water containing long fibers of a pulp used in the production process of pulp and paper, contaminants adhered onto pulp fibers and / or inorganic particles are separated, and the stickiness of the contaminants is lowered, and microorganisms are reduced, whereby the process water is clarified, resulting in the production of high-quality pulp and paper. In the first invention, in the production process of pulp, cavitation is allowed to occur in a pulp suspension preferably by liquid jet flow. Fine bubbles produced by cavitation are introduced into the pulp suspension, and the pulp is regulated to a desired freenessby taking advantage of impact power created upon the collapse of the fine bubbles. In the second invention, process water in which the content of long fibers in pulp used in the production process ofpulp and / or paper is not more than 50% by weight based on the total solid content, is treated by cavitation generated by liquid jet flow and is then returned to the production process of pulp and / orpaper for reutilization.

Description

technical field [0001] The first invention of the present invention relates to a pulp beating method, paper made from the pulp produced by the method, and printing paper such as coated paper. In more detail, it relates to a method for producing bulky pulp by using kraft pulp of coniferous trees, broad-leaved trees, non-wood fibers, mechanical pulp, and newspapers, advertisements, magazines, information recording paper, copying, Recycled pulp composed of printed waste paper such as computer printing, or a mixture of old magazines, office waste paper, etc., and in the process of making pulp from these mixtures, cavitation occurs in the pulp suspension, and fine air bubbles will be accompanied by cavitation Actively introduced into the pulp suspension, using the impact force when the air bubbles collapse, suppressing damage such as pulp fiber shortening, while adjusting to the desired freeness, to produce bulky pulp. [0002] The second invention of the present invention relates...

AI Technical Summary

Problems solved by technology

However, the above-mentioned methods have the following problems: the pulp cannot be recycled repeatedly, and the strength and stiffness of the paper will be significantly reduced due to the hindrance of the bonding between the fibers. Adding other medicines and fillers to the pulp will inevitably increase the cost. New problems such as increased foaming and reduced size will occur

[0030] However, since these ultrasonic vibrators are used in an open system, the effect of cavitation will be reduced. Since there is only a single frequency and the range of action is narrow, the expected effect of the present invention cannot be obtained.

[0031] Japanese Patent Laid-Open No. 2004-19025 (Patent Document 3) proposes to use a solvent to treat foam or white water and separate ink components for reuse. However, since kerosene and n-hexane are used, safety is still a problem.

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