| Water-based ink,as a kind of environmentally friendly printing materials,is widely used in the printing process of paper products.However,during the recycling process for the water-based ink printed wastepapers,it’s easy for the water-based ink particles to be readsorbed by fibers due to their small size and good hydrophilicity.The adsorption capacity of different kinds of waste paper fibers is influenced by pore structure and properties.In this paper,kinetic and thermodynamic models were used to investigate the adsorption process of different types and different fibers on water-based ink particles,to explain the water-based ink particles on different fibers adsorption of different reasons,and then explore the hybrid system in different fiber adsorption phenomenon of water-based ink particles of the competition,in order to improve the water-based ink printing waste paper fiber classification in the process of recycling and utilization efficiency,but also provide certain theoretical basis for waste paper pulp sizing reuse and application foundation.Finally,a variety of different types of papermaking additives are used to improve the size and hydrophobicity of water-based ink particles,and explore the effect of the additives,so as to reduce their adsorption and deposition on fiber.Firstly,the re-adsorption process of water-based ink particles on different fibers was simulated to explore the influence of different fibers on the adsorption amount of water-based ink particles under the different conditions,and the kinetic and thermodynamic models were used to analyze it.The results show that the quasi-second-order adsorption kinetic model is more suitable for describing the adsorption process of water-based ink particles.For different fractions of SBKP fibers,water-based ink particles have the largest adsorption capacity onto the P50/R100 fiber fraction,and there is 1 mg/g more than that onto the R30 fiber fraction.Its adsorption rate is 2 times faster at the initial stage than that onto the R30 fiber fraction.The adsorption capacity of TMP fiber was smaller than that of SBKP fiber,and the maximum adsorption capacity was 0.8 mg/g lower.In addition,the adsorption process of water-based ink particles on pulp fibers follows the Freundlich isotherm adsorption,and this process is a spontaneous and exothermic process.Water-based ink on the R30 fiber fraction has the largest adsorption enthalpy change,and that on the P50/R100 fiber fraction has the largest adsorption entropy change.Secondly,the competitive adsorption process of water-based ink particles by different pulp fibers in the mixing system was simulated and studied.The results showed that among different fractions of the same pulp fibers,the P50/R100 fraction fibers have stronger competitive adsorption ability than the R30 fraction fibers.Among different kinds of fibers with the same fraction,SBKP fiber has stronger competitive adsorption ability than TMP fiber.The competitive adsorption between different kinds of fibers and different fraction fibers mainly depends on the difference of adsorption capacity between different fibers.Finally,inorganic and organic additives and surfactants were used to enrich water-borne ink particles.The results show that PAC and CPAM,which are commonly used in water-based ink wastewater treatment,have a good effect on the enrichment of water-based ink particles.When PAC concentration is 30 mg/L,water-based ink particle size up to 35 μm and has certain hydrophobicity,paper whiteness can reach 83.3%ISO.When the CPAM concentration is 12 mg/L,water-based ink particle size up to 37.2 μm and has a certain hydrophobicity,and the whiteness of the paper can reach 80.6%ISO,the two additives have better enrichment effect when used in combination.When using CaCl2 and CTAB on water-based ink particles,when CaCl2 concentration is 0.2 mol/L,water-based ink particle size can reach 3.8 μm,with a certain hydrophobicity,paper whiteness up to 84.2%ISO.When the CTAB concentration is 0.1 mmol/L,the water-based ink particle size up to 1 μm,can not change its hydrophobic performance,paper whiteness decline.Compound with two kinds of additives,they show synergistic relationship. |
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