The Study On Textile Structure And Mechanical Properties Of Medical Compression Stockings

Medical compression stockings are effective ways to treat and prevent venous dilatation disease, but clinical products used in compression stockings stress failure remains a problem, especially for domestic products. Therefore, this study researched and collected three representative compression stockings domestic products:long stocking with the pressure medium grade Ⅱ (Ⅱ ZM-L), long stocking with the pressure low grade Ⅱ (Ⅱ ZS-L), short compression stocking with the pressure medium grade Ⅱ (Ⅱ ZM-L). Secondly, we analyzed and compared the differences among these products’ features and morphology, loop structure, yarn structure and mechanical properties. The results showed that the pressure of compression stockings existed declining trend in short term.Then, we compared the mechanical properties of yarn used in three pressure stockings with the typical imported yarn which have the same specifications. Experimental results showed that two kinds of yarns have a large difference in the mechanical properties. In the case of small tensile and stress small strain, imported yarns exhibit good tensile strain capacity. In the case of large tensile stress and large strain, domestic yarns exhibit good tensile strain capacity. In order to explore the reasons for the difference between the two yarns, the analysis derived from the microscopic structure shows that mechanical properties of the yarn core, outsourcing yarn coated angle, covering twist and covering line specifications have a significant impact on the yarn’s mechanical properties. However, the core revealed phenomena has no obvious regularity with the mechanical properties of covering yarns. Therefore, tight inside and loose outside structure of the yarn are more appropriate. That is outsourcing yarn twist is greater than inner yarn twist.At last, according to the above results, a series of spandex covering yarns has been designed and fabricated with different elongation rate of spandex core yarn, which are3.5%,3.8%,4%,4.3%,4.5%,4.8%,5%,5.3%,5.8%. And the covering molding process would be optimized. The results showed that the elastic recovery of the spandex core yarn (elongation rate4.5%) was the best in the nine kinds of yams in once stretch. The elastic recovery of the spandex core yarn (elongation rate5.0%) was the best in the nine kinds of yarns in multiple cycles stretch. It stands that its elastic properties is the best. But as the elongation rate of spandex core yarn increases, the yarns’ stress failure is increased. However, when elongation rate increased, yarn production increased and spandex core yarn saved. Taking all factors to consider, when knitting and using medical compression stockings, yarns would be repeatedly stretched, so we select the elongation rate5.0%of the yarn which elastic recovery was the best in the nine kinds of yarns in multiple cycles stretch. And we compared the mechanical properties of5.0%elongation rate yarns with the typical imported yarns which have the same specifications and the three pressure stockings used yarns, found5.0%elongation rate yarn’s elastic recovery was better than the three pressure stockings used yarns, closed to the typical imported yarn’s elastic recovery. That is5.0%elongation yarn’s tensile properties are better than the three pressure stockings used yarns. Therefore, the spandex core yarn’s elongation was set to5.0%will improve the covering yarn quality. These findings are expected to provide theoretical guidance and experimental basis for further improving the quality of existing products or develop new products.