Progress in Research on Re-adsorption and Separation of Aqueous Ink Contaminants During Waste Paper Reuse
With the continuous improvement of people’s living standards in China, the consumption of paper and paperboard is also increasing. In order to effectively alleviate the shortage of raw materials, energy shortages and high pollution loads faced by the paper industry, more and more waste paper is used to replace wood. Pulping. In the past decade, waste paper has become an important part of the raw materials for the paper industry. According to the annual report of the China Pulp and Paper Industry , the total pulp consumption in the country reached 97.97 million tons in 2016, of which 63.29 million tons of waste paper pulp accounted for 65% of the total pulp consumption. It can be seen that waste pulp has now become China's The main raw material for papermaking.
In waste paper recycling, a large part of it is used to produce deinked pulp for the production of newsprint and wrapping paper. At present, the key technical problems in the recycling of waste paper are mainly reflected in two aspects: First, in the recycling process of waste paper, how to reduce the impact of stickies from waste paper materials on the quality and production of waste pulp; second, waste paper The deinking efficiency is how to remove the impurity components such as ink particles in the pulp in the deinking process to achieve the purpose of improving the whiteness of the deinked pulp. In recent years, with the rapid development of new paper processing technologies and printing technologies, in order to meet the needs of environmental protection, the proportion of water-based ink publications has increased year by year, foreign newsprint (using flexo printing) and domestic packaging paper (corrugated cardboard boxes, etc.) ) Water-based inks have been used for printing. However, this type of aqueous ink print has a problem of difficulty in deinking in the recycling of waste paper. At present, in some domestic large newsprint paper mills or paper production lines using waste paper pulp as raw materials, the presence of water-based ink prints seriously affects the production efficiency and product quality of the waste paper recycling process. In a factory deinked using a conventional flotation method, even if only a small amount of water-based ink is present, the whiteness of the deinked pulp will be greatly reduced, and only a 10% water-based ink print can be allowed to exist .
The problem of difficulty in the flotation and deinking of water-based ink printing waste paper has caused the industry's high attention, so it is urgently needed to comprehensively analyze the ink impurity components of the water-containing ink printing waste paper, and then re-adsorption and separation of ink impurities in the pulp fiber system. The mechanism was studied to develop a flotation and deinking process technology suitable for printing waste paper containing hydrous ink.