Purpose

This study aims to accurately simulate the tilting separation process of mask projection stereolithography (MPSL) and verify the tilting theory.

Design/methodology/approach

The finite element separation models of MPSL 3D printing process were established. The established models simulated both tilting and pulling-up separation process by changing the constraints and boundary conditions. The bilinear cohesive curves were used to define the separation interface. The stress distribution of the cured part and FEP film at different times during the whole separation process was extracted. Different orientations of pulling-up and tilting were also compared for stress distribution. The stress change was analyzed for the center and edge points of the upper surface of cured part.

Findings

The results showed that the stress increased with the separation speed, and the stress at the edge position of exposure area was greater than the internal position. The tilting traction stress distribution was affected by the exposure area function and the velocity distribution. Alternation of the exposure area function changed the cohesive stiffness. The non-coincidence of the calculated traction stress with the input bilinear cohesive curve reflected the influence of the material properties and the separation methods. The high-speed side of tilting had fast separation and high traction stress.

Originality/value

This study proposes a technical method for simulation tilting separation and verified the tilting theory. The cohesive zone model was proved applicable to the tilting traction stress calculation.

中文翻译：

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掩膜投影立体光刻工艺倾斜分离模拟与理论验证

目的

本研究旨在准确模拟掩模投影立体光刻（MPSL）的倾斜分离过程并验证倾斜理论。

设计/方法/方法

建立了MPSL 3D打印过程的有限元分离模型。建立的模型通过改变约束和边界条件来模拟倾斜和上拉分离过程。双线性内聚曲线用于定义分离界面。提取了整个分离过程中不同时间固化部分和 FEP 薄膜的应力分布。还比较了上拉和倾斜的不同方向的应力分布。分析了固化件上表面的中心点和边缘点的应力变化。

发现

结果表明，应力随着分离速度的增加而增加，且曝光区边缘位置的应力大于内部位置。倾斜牵引应力分布受暴露面积函数和速度分布的影响。暴露面积函数的交替改变了内聚刚度。计算的牵引应力与输入的双线性内聚曲线的不一致反映了材料特性和分离方法的影响。倾斜高速侧分离速度快，牵引应力高。

原创性/价值

本研究提出了一种模拟倾斜分离的技术方法，并验证了倾斜理论。内聚区模型被证明适用于倾斜牵引应力计算。