基于响应曲面法的木塑复合3D打印线材挤出参数优化

Optimization of Extrusion Parameters of Wood-Plastic Composite 3D Printing Filament Based on Response Surface Method

以杨木粉与聚乳酸为主要原料、柠檬酸三丁酯为增塑剂,利用熔融挤出法制备了聚乳酸/木粉复合3D打印线材。采用3D打印线材制备的试件作为研究对象,在单因素实验的基础上,选取挤出温度、木粉含量和增塑剂含量为自变量,试件拉伸强度为响应值,采用中心组合设计的方法研究了各自变量及其交互作用对试件拉伸强度的影响。利用响应曲面分析方法建立了拉伸强度的二次多项数学模型,并根据实际选择响应曲面方程,利用最小二乘法估计相应的系数,剔除最不显著因素,建立最终的数学预测模型。结果表明：通过响应曲面法优化得出的最佳挤出温度、增塑剂含量、木粉含量分别为172.6℃、4%和14.1%,此时试件的拉伸强度为24.231 8 MPa,这一数值较优化前提高了2.12%。该预测模型能很好地描述试件拉伸强度与挤出温度、木粉含量和增塑剂含量之间的关系,可以对试件拉伸强度进行分析和预测。

By using poplar flour, poly（lactic acid） as main raw material, and tributyl citrate as plasticizer, a poly（lactic acid）/wood flour composite 3D printing filament was prepared via a melt extrusion method. In this experiment, the specimen prepared by 3D printing filaments were taken as the research object, based on the single factor test, the extrusion temperature, the content of wood flour and the content of plasticizer were taken as independent variables, and the tensile strength of the specimen was the response value, and the effects of the respecti~/e variables and their interactions on the tensile strength of the specimen were studied by using the central composite design method. The quadratic polynomial mathematical model of tensile strength was established by using the response surface analysis method. Based on the actual selection of response surface equation, the least squares method was used to estimate the corresponding coefficient, and the least significant factor was removed to establish the final mathematical prediction model. The results showed that the optimum extrusion temperature was 172.6~C, the content of plasticizer was 4% and the content of wood flour was 14.1%. The tensile strength of the specimen obtained by using those optimized extrusion parameters was 24.231 8 MPa, and the value was improved by 2.12% compared with the initial extrusion parameters. The prediction model can describe the relationships between the tensile strength and the extrusion temperature, the content of wood flour and plasticizer, which can be used to analyze and predict the tensile strength of the specimen.