Research on the Measurement of the Effective Thermal Conductivity of LDPE Powder by the Hot Needle Probe Method

本文基于热探针法，通过设计新的测量仪器和算法，研究了粒径为(500 μm, 800 μm)和(800 μm, 1000 μm)的低密度聚乙烯(LDPE)粉末体积分数与导热系数的关系，并与各种理论预测进行了对比。实验表明，在不同体积分数下的LDPE粉末的热导率位于Bruggeman模型与Maxwell-Eucken模型之间，并通过线性拟合对体积分数在(0.35, 0.58)的LDPE粉末的有效热导率进行了拟合。This study investigates the relationship between volume fraction and thermal conductivity of low-density polyethylene (LDPE) powders with particle size ranges of (500~800) μm and (800~1000) μm using an improved thermal probe methodology. A novel measurement apparatus and cor- responding algorithm were developed to enhance measurement accuracy. Experimental results demonstrate that the effective thermal conductivity of LDPE powders at different volume fractions falls within the bounds predicted by the Bruggeman model and Maxwell-Eucken model. Specifically, for powders with volume fractions in the range of [0.35, 0.59], a linear regression model was established to characterize the effective thermal conductivity, showing good agreement with experimental data.