目的 研究在制袋—充填—封口包装机中,当拉伸包装薄膜经过翻领成型器时,翻领成型器对包装薄膜厚度的影响。 方法 从几何非线性角度研究包装薄膜经过翻领成型器最高点后其厚度的变化情况,并与薄膜初始厚度进行比较。 结果 通过分析包装薄膜内各质点间的相对位移及其相对运动的速度与加速度的关系式,可以看出相对位移、相对速度及相对加速度越大,则薄膜的厚度将变得越小,薄膜的变形量也越大。 结论 给出了描述材料变化的变形梯度张量、位移梯度张量、速度及加速度的关系式,并推出了一个关于包装薄膜厚度变化的关系式,为实际翻领成型器制作中肩曲面偏移问题提供一定的理论基础。

Objective To study the effects of the lapel shaper on the film thickness when the packaging film went through the lapel shaper during the stretching process in the FFS packaging machines. Methods This paper researched the thickness change of the packaging film when it went through the lapel shaper from the perspective of geometric nonlinearity, and compared it with the initial thickness. Results By analyzing the formulas of the relative displacement, relative velocity and acceleration, it was found that with the increase in the relative displacement, relative velocity and acceleration, the film thickness decreased, and the amount of deformation increased. Conclusion Formulas of deformation gradient tensor, displacement gradient tensor, velocity and acceleration were given, and a formula on the thickness variation of packaging film was introduced. This research provided theoretical foundations for the shoulder surface offset problem of the lapel shaper in the actual production process.