考虑几何特征的纸浆模塑收缩率实验研究

Experimental Study on Molded Pulp Shrinkage Considering Geometric Features

目的为高精度设计纸浆模塑产品探索基础数据。方法考虑纸浆模塑的几何特征,通过现代测试仪器对实际生产纸浆模塑不同截面的几何形状进行测试,得到其截面形状的几何数据,再通过数据拟合方法得到其几何特征的几何尺寸,最后按照收缩率的定义,得到其不同几何特征的收缩率。结果脱模斜度收缩率均值为5.71%;中间长度方向上凸型腔的收缩率为负,其长度越大,伸长率越小;下凹型腔的收缩率为正数,其长度越大,收缩率越小;型腔高度的变化率均值为4.7%;倒角圆弧半径尺寸变化较大,其收缩率均值为70.61%。结论克服了以往研究者只通过正规纸浆模塑试样(正方形)研究纸浆模塑收缩率的缺点,为纸浆模塑的精确设计提供了基础数据。

The work aims to explore basic data for high-precision design of molded pulp products.Considering the geometrical characteristics of pulp molding,the geometry of different cross sections of the actually produced molded pulp was tested by modern test instruments to get the geometrical data of cross section,and the geometrical dimensions of the geometrical features were obtained by data fitting method.According to the definition of shrinkage,the shrinkage of different geometric features was obtained.The mean rate of film shrinkage was 5.71%.The shrinkage rate of the convex cavity in the middle along the length direction was negative,and the larger the length was,the smaller the elongation was.The shrinkage of the concave cavity was a positive,and the larger the length was,the smaller the shrinkage was.The mean rate of change in cavity height was 4.7%.The radius of the chamfered arc changed greatly,and the average shrinkage rate was 70.61%.The work has overcome the shortcomings of previous researchers to study the shrinkage of molded pulp only by regular molded pulp samples(squares),thus providing basic data for the precise design of molded pulp.