Method for making paperboards by using paper mill sludge

Abstract

The invention provides a method for making paperboards by using paper mill sludge. The method comprises the following steps: by using paper mill sludge as auxiliary materials for making the paperboards by adopting an interlayer filling technology, fully mixing the paper mill sludge subjected to impurity removal pretreatment with a reinforcing agent, uniformly applying a mixture between two wet paper sheets, pressing, drying and finishing, thus forming the paperboards similar to sandwich structures. Compared with a conventional technology for making the paperboards through wet-end paper mill sludge addition, the method provided by the invention has the advantages that the added paper mill sludge can be mostly remained in the paperboards so as to form packing layers, thus the retention of the paper mill sludge in the paper boards is increased, and the method is simple in process, strong in operability and convenient to implement through an interlayer spraying method in a conventional papermaking process. The paper mill sludge is added to the paperboard making process so as to make the paperboard products meeting the quality requirements, so that the cost of fiber raw materials is saved for papermaking enterprises, and the purpose of digesting paper mill sludge solid waste in the enterprises is also achieved; the method is an effective approach for the resource utilization of the paper mill sludge.

Description

technical field [0001] The invention relates to a production method of cardboard, in particular to a method for making cardboard by using papermaking sludge as an auxiliary material. Background technique [0002] Papermaking sludge is a bulk solid waste produced in the process of pulping and papermaking. Its organic matter content is high (40%-60%), its chemical composition is complex, but its heavy metal content is low, so it has a high potential for comprehensive utilization. According to statistics, every ton of paper produced can produce 50-250 kg of dry sludge and solid waste (varies with different production conditions). According to the current paper production capacity in my country is close to 100 million tons per year, and the amount of sludge produced is very considerable. Due to the large output, complex composition and high water content of papermaking sludge, the industry has not yet found an effective way to dispose of it, and the embarrassing situation of "s...

AI Technical Summary

Problems solved by technology

Due to the characteristics of large output, complex composition and high water content of papermaking sludge, the industry has not found an effective way to dispose of it so far, and the embarrassing situation of "sludge disaster" is common in papermaking enterprises

Most of the disposal of papermaking sludge currently uses methods such as landfill and incineration. Due to the problems of large land occupation, low thermal energy efficiency and air pollution, the above methods are still difficult to be accepted by the industry and society.

[0003] In the prior art, there is an attempt to use papermaking sludge as an auxiliary material to add and reuse the wet end in the process of making paperboard, but this method has problems such as low sludge retention rate and affecting paper dehydration.