约束面投影成型基底表面微织构特征对固化层分离力的影响  

Influence of Micro-texture Characteristics of Substrate on Separation Force in Constrained-surface Projection Based Stereolithography

作　　者：王权岱[1] 杨新宇 惠振文 赵仁峰 杨振朝[1] 郭美玲 李言[1] WANG Quandai;YANG Xinyu;HUI Zhenwen;ZHAO Renfeng;YANG Zhenchao;GUO Meiling;LI Yan(School of Mechanical and Precision Instrument Engineering,Xi'an University of Technology,Xi'an 710048)

机构地区：[1]西安理工大学机械与精密仪器工程学院,西安710048

出　　处：《机械工程学报》2021年第17期196-206,共11页Journal of Mechanical Engineering

基　　金：国家自然科学基金资助项目(51775431,51905423,51805433)。

摘　　要：针对约束面投影成型工艺中固化层自基底分离过程中分离力过大而影响成型效率、可靠性的问题,提出采用微织构化PDMS膜作为约束基底以减小分离力的方法。采用双线性内聚本构模型对固化层自基底分离过程进行了数值模拟,探究了不同微织构形状(圆形、方形、三角形)、面积率、高度对黏附力的影响规律,结果表明,三角形微织构阵列更有利于减小黏附力;黏附力随织构面积率的增大而增大;不同微织构高度对黏附力的影响效果较小。利用硅基模具ICP刻蚀结合微模铸工艺制备了表面具有不同微织构形状及阵列间距的PDMS膜,并对不同基底微观织构条件下固化层自基底的分离力进行了试验研究,试验结果与数值计算结果吻合较好。在最佳织构特征条件(微织构形状为三角形、间距15μm、高度为10μm)下,相对于光滑平膜,固化层从织构化基底表面的剥离力减小了约60%。In constrained-surface projection based stereolithography process,a significant pulling-up force is requuied to separate the cured part from the bottom surface of the resin vat,which reduces the throughput and reliability of the process.In order to solve the problem,a method for the separation force reduction by taking the micro-textured PDMS film as constraint substrate is proposed.The bilinear cohesive constitutive model was used to simulate the separation process of the cured layer from the substrate,and the effects of micro-texture characteristics involving geometry shape,area ratio and height on the adhesion force were investigated.The simulation results show that compared with the micro-textures with circular and square section shape,the micro-texture of triangular is more conducive to reduce the adhesion force;the adhesion force increases with the increase of the texture area ratio and the texture height shows an insignificant effect on adhesion force.PDMS films with different texture shape and spacing are prepared through silicon-based mold ICP etching combined with cast molding process and then the effects of micro-texture geometry features of substrate on separation force of solidified layer are studied experimentally.The experimental results agree well with the numerical calculation results.Under the optimal texture characteristics(micro-texture with triangular cross section,texture with spacing of 15μm and height of 10μm),the separation force of the cured layer from the textured substrate surface is reduced by about 60%compared with the flat film on the substrate.

关 键 词：约束面投影 分离力 内聚力模型 数值模拟 微织构 

分 类 号：TB124[理学—工程力学]