球窝型动态混合器的结构设计及其混合效果研究

Structure Design and Mixing Effect of Spherical Cavity Mixer Mounted on Single-screw Extruder

针对聚丙烯树脂基微孔木塑复合材料制备过程中存在的颗粒团聚问题,采用球窝型动态混合器来增强装置的分散混炼能力,并通过分析不同球窝尺寸下腔穴壁厚、转子长径比及其理论分流数来确定动态混合器的结构参数。结果表明,球窝型动态混合器的串联可以有效促进填料的均匀分散、改善试件的表观质量。但对木粉等热敏材料而言,混合器表面腔穴间的强剪切作用极易引发其热解行为,故在设计过程中需要合理选择周向及轴向腔穴数量。

In order to solve the problem of particle agglomeration during the preparation of polypropylene-based microporous wood polymer composites,the spherical cavity mixer was mounted on the screw to enhance the dispersive mixing ability of the device.And the effects of cavity size on the wall thickness,rotor length diameter ratio and theoretical split number were investigated by mathematical calculation.The experimental results indicate that the application of spherical cavity mixer could effectively promote the uniform dispersion of fillers and improve the apparent quality of specimens.However,for wood flour and other thermal sensitive materials,the strong shear effect between cavities on the mixer surface can easily lead to its pyrolysis behavior,so it is necessary to reasonably select the number of circumferential and axial cavities in the design process.