Surfactants have excellent performance in decontamination

2022-10-26 17:00:02

Anionic surfactant has excellent performance in decontamination, but it is often used with non-ionic surfactant to obtain better deinking effect. Anionic surfactant has good foaming and degreasing properties, and non-ionic surfactant presents non-ionic state in aqueous solution with high stability. When nonionic surfactant and anionic surfactant are used together, the colloidal particles will be negatively charged and repel each other with the same charge, forming a stable dispersion system, which is conducive to the separation and removal of ink and fiber.

According to the characteristics of surfactants, 9 types of surfactants were selected. Seven of them were selected and deinking tests were conducted with a single surfactant. Five compounds with good results were selected. Orthogonal experiments were carried out for the optimum compound formula 3, and the optimal process conditions were determined as A3B2C1D3, that is, the pulp concentration was 9%, the deinking agent dosage was 0.8%, the deinking temperature was 50 ℃, and the deinking time was 50 min. The whiteness of the deinked newsprint pulp was up to 56.1%.

Paper is an important packaging material. With the increasing demand for paper and paperboard, it is bound to lead to a shortage of raw materials, energy shortages and other problems. Due to the limited forest resources and the shortage of water resources in China, it can not meet the demand of the paper industry. Therefore, the recycling of waste paper and paper products is crucial in today's advocacy of ecological civilization and circular economy.

Worldwide, 54% of waste paper is used as cardboard, 15% as packaging paper, 12% as newsprint, 10% as toilet paper, and 7% as printing and writing paper. Waste paper paper-making can save complicated wood raw material preparation, cooking, bleaching and other processes. The key of waste paper utilization is deinking technology. Surfactants are the main active components of waste paper deinking. In this paper, the performance of different surfactants is compared and selected, and they are applied to the chemical washing deinking of waste newsprint, and their appropriate processes are discussed.

Compared with the blank sample, the whiteness of each deinked pulp after adding the surfactant has been improved to a certain extent. This is because after adding the surfactant, its hydrophobic group will be combined with the ink, and at the same time, one end of the hydrophilic group will remain in the water, changing the interface performance of the ink, making it become a substance easily dissolved in water, that is, the wetting, penetration Emulsion dispersion, solubilization and other functions make the ink better separated from the fiber and dissolved in water to remove.