The mechanical properties of molded pulp materials are the basis of the structural optimum design of molded pulp products. Therefore, the correlations between Poisson’s ratio and fiber structure, molding process, and thickness were found for materials including wood pulp, bamboo pulp, sugarcane pulp, white mixed pulp, black mixed pulp, recycled corrugated board pulp, and recycled newspaper pulp by the uniaxial tensile test and digital image correlation method. The fiber structures of the selected molded pulp materials were investigated by scanning electron microscopy. The results revealed Poisson’s ratios of wood pulp, bamboo pulp, sugarcane pulp, white mixed pulp, black mixed pulp, recycled corrugated board pulp, and recycled newspaper pulp to be 0.169, 0.108, 0.202, 0.120, 0.166, 0.098, and 0.044, respectively. Microstructural investigation further revealed that Poisson’s ratios of molded pulp materials were related to the fiber structure and drying method. The pulp material dried outside mold under lower pressure and temperature had a smaller Poisson’s ratio, while that dried inside mold under higher pressure and temperature had a larger Poisson’s ratio. The layered phenomenon of the molded pulp materials was also found by scanning electron microscopy images: the outer layer was denser than the inner layer. These results can provide guidance for the numerical simulation analysis and optimal design of molded pulp products.

中文翻译：

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用数字图像相关法和单轴拉伸试验测定模塑纸浆材料的泊松比

模塑纸浆材料的力学性能是模塑纸浆产品结构优化设计的基础。因此，对木浆、竹浆、甘蔗浆、白混浆、黑混浆、再生瓦楞纸板浆、再生报纸浆等材料的泊松比与纤维结构、成型工艺和厚度之间的相关性进行了单轴分析。拉伸试验和数字图像相关法。通过扫描电子显微镜研究所选模塑纸浆材料的纤维结构。结果表明，木浆、竹浆、甘蔗浆、白混浆、黑混浆、再生瓦楞纸板浆和再生报纸浆的泊松比分别为0.169、0.108、0.202、0.120、0.166、0.098和0.044。 . 微观结构研究进一步表明，模塑纸浆材料的泊松比与纤维结构和干燥方法有关。在较低压力和温度下模具外干燥的纸浆材料具有较小的泊松比，而在较高压力和温度下模具内干燥的纸浆材料具有较大的泊松比。通过扫描电镜图像也发现了成型纸浆材料的分层现象：外层比内层致密。这些结果可为模塑纸浆制品的数值模拟分析和优化设计提供指导。而在较高压力和温度下在模具内干燥的则具有较大的泊松比。通过扫描电镜图像也发现了成型纸浆材料的分层现象：外层比内层致密。这些结果可为模塑纸浆制品的数值模拟分析和优化设计提供指导。而在较高压力和温度下在模具内干燥的则具有较大的泊松比。通过扫描电镜图像也发现了成型纸浆材料的分层现象：外层比内层致密。这些结果可为模塑纸浆制品的数值模拟分析和优化设计提供指导。