牙膏灌装机构设计及流动特性分析

Design and Flow Characteristics Analysis of Toothpaste Filling Mechanism

目的通过设计双头平推柱塞式灌装机构,进一步提升牙膏等黏稠膏体的灌装生产效率,同时研究牙膏流变特性对灌装推力的影响,以解决当前牙膏等粘稠膏体灌装速度、精度低等问题。方法首先选取市场占有率较高的品牌牙膏进行流变试验,然后采用经典非牛顿流体本构方程拟合获得流变曲线,最后采用数值模拟物料灌装挤出过程,获得所需要的最大灌装推力。结果研究表明,牙膏属于非牛顿流体且具有剪切稀化的流变特性,与幂律流变模型(Powder Law黏度模型)拟合相关性为0.9992。在最大灌装容量为200 mL、最大灌装速度为0.337 m/s时,所需推力为1681 N。结论可为非牛顿流体的灌装机构设计提供理论指导。

The work aims to design a double-head flat-push plunger filling mechanism to improve the filling and production efficiency of the viscous pastes,such as toothpaste and study the effect of the rheological characteristics of toothpaste on filling thrust at the same time,so as to solve the current problems of low filling speed and accuracy of toothpaste and other viscous pastes.Firstly,the toothpaste with high market share was selected for the rheological test,and then the rheological curve was fitted by the classical non-Newtonian fluid constitutive equation.Finally,the filling and extrusion process of material was simulated to obtain the maximum filling thrust required.According to the study results,toothpaste was a non-Newtonian fluid and had rheological properties of shear thinning.The correlation coefficient between the toothpaste and the power-law rheological model(Powder law viscosity model)was 0.9992.At the maximum filling capacity of 200 mL and the maximum filling speed of 0.337 m/s,the required thrust was 1681 N.The conclusion can provide theoretical guidance for the filling mechanism design of non-Newtonian fluid.