芯壳结构竹塑复合材料密度及微观结构的CT分析

以竹屑、高密度聚乙烯(HDPE)、竹浆纤维、纳米碳酸钙及白泥为主要材料,采用聚合物共挤出技术制备芯壳结构竹塑复合材料。利用Micro-CT扫描技术对复合材料内部结构进行了观测,同时还对断面密度进行了分析。结果表明,通过对不同壳层材料的复合材料断面CT图像进行二值化处理后,可清晰地反映复合材料内部缺陷。Micro-CT三维空间分析技术能够实现对4种不同壳层材料的芯壳结构竹塑复合材料的内部微观结构可视化的精细表征,且重建密度表现出与实测密度趋势一致。壳层加入白泥或纳米碳酸钙的复合材料的剖面密度在厚度方向上呈现出壳层密度高而芯层密度低。不同壳层材料的复合材料CT图像阈值分布在26.1到95.6之间,在此基础上建立了CT图像阈值与密度的关系。

Density Distribution and Microstructure of Core-Shell Structured Bamboo Plastic Composites

With bamboo residue,high density polyethylene (HDPE),bamboo pulp fiber,nano-CaCO3 and white mud as main materials,core-shell structured bamboo plastic composites were manufactured by co-extrusion technology in the process of polymer molding.The internal microstructure of core-shell structured bamboo plastic composites was investigated through micro-CT scan technology,and the vertical density profile was analyzed.The results of the micro-CT image show that compared with the untreated images,the CT images of cross section with different shell layer materials can be more clearly reflected about the inner defections of the tested composites based on binarization processing.The spatial visualization of internal microstructure was done by three-dimensional space analysis technology for the 4 kinds of core-shell structured bamboo plastic composites with different shell layer materials.The trend of reconstruction density shows consistent with the measured density.The vertical density profile of the core-shell structured bamboo plastic composites with HDPE/white mud and HDPE/nano-CaCO3presents higher density of shell and lower density of core layer.The threshold values of CT images are different significantly with different shell layer materials,the values distribution range from 26.1 to 95.6.The CT values provide the important foundation to analyze the relationship between threshold value and mean density.