水性油墨热风干燥机理及数学模型研究

Research on the Mathematical Model and Hot-Air Drying Mechanism of Water-Based Ink

当前,随着人们对环保及食品、药品安全问题越来越重视,绿色印刷与包装技术的研究和应用也越来越广泛,其中水性油墨逐渐被市场接受。但是,目前国内与水性油墨配套的印刷发备多数存在烘干效率低,从而导致印刷速度难以提升的问题。为解决此问题,本论文以Logarithmic模型为基础,分析水性油墨的热风挥发干燥机理和过程。在热风温度为50℃,热风流速为6m/s的条件下,假设实验条件遵循费克第二定律:干燥初始阶段,固体基质的流体均匀分布;干燥过程中,扩散系数保持不变;表面传热传质阻力忽略不计以及保持体系一维扩散等。在该实验条件下,对水性油墨在干燥过程中残留流体比例进行测量并记录,然后对实验数据进行非线性回归(Orign统计软件),以相关系数的平方作为评价模型的依据,并对Logarithmic模型进行修正,得出与水性油墨干燥过程吻合的改良模型。最终模型能够准确预测水性油墨干燥效率,而且能够为水性油墨印刷设备的设计提供基础数据,同时,对相关印刷设备印刷速度的提高具有积极意义。

At present, with more and more attention to environmental protection, food and medicine safety, research and application on green printing and packaging technique are more abroad. Around these, water-based ink has been accepted by the market step by step, but the printing press on this area still has some problems such as low drying efficiency and lower printing speed. To solve these problems, the hot-air drying process based on Logarithmic model was analyzed in this paper. The experiment condition was supposed as follow： the temperature was 50℃, the hot-air speed was 6 m/s, and the experiment also kept to Fick＇s second law. the liquid equally distributed in the solid at the beginning; during the drying process, the diffusing modulus kept steady; the resistance of external diathermanous medium was ignored and kept linear diffuse and so on. Under these experimental conditions, the data about the volume of liquid was recorded in the solid during the process, and then the data by the software Origin was analyzed, the model with the square of relating parameters was evalua- ted, and then the model was revised so that it could keep the same with the drying process. The model can forecast the drying rate of the water-based ink. And this model can supply basal dada for the designing work of the press using water-based ink. Additionally, it has actively influence on improving the speed of the printing press.