三种耐高温纱线的结构与性能测试评价

Study on the structure and performance of three thermal resistance yarns

玄武岩、芳纶、胛FE（聚四氟乙烯）等纱线广泛应用于高温过滤领域。对这三种纱线的结构形态、力学性能、热学性能进行测试评价。结果表明：三种纱线表面形态光滑，高温下纱线表面出现损伤；三种纱线常温下强度为2．8～5．8cN／dtex，较常规化纤强度高；比较三种纱线的拉伸性能发现，PTFE纱线“小张力大变形”，形态稳定性差，玄武岩纱线的弹性模量最大，刚度大，芳纶纱线的断裂强度最大，能耐较大外力；经140～260℃高温处理后，三种纱线的力学稳定性好，相比而言，芳纶纱线经高温处理后强度降低最快，PTFE纱线的强度稍有降低，玄武岩纱线的强度基本保持不变；三种纱线的勾结强度保持率差别较大，PTFE纱线的勾结强度明显高于其他两种纱线，耐弯曲性较好；三种纱线的起始分解温度均在500℃以上，热稳定性好；当温度超过500℃时，芳纶、PTFE纱线的热重损失迅速增大，但玄武岩纱线的热重损失较小。

Basalt yarn, aramid yarn and PTFE yarn are the three common yarns used in the high temperature filtration field. The morphology, mechanical properties and thermal properties of these three yarns were tested and evaluated. The results show that the surface of three yarns is smooth at room temperature, but damaged at high temperature. The strength of these yarns varies from 2.8 cN/dtex to 5.8 cN/dtex, higher than that of normal chemical fiber yams. By the comparison of the tensile properties among three yams, it is found that PTFE yarn has large deformation under small tension and poor shape stability; basalt yarn has maximum modulus of elasticity leading to big stiffness and less tendency of deformation. In case of external force is large, priority should be given to aramid yarn due to its largest strength. These three yams, after treated under 140 ℃ to 260 ℃, show good mechanical stability. Comparatively, after high-temperature treatment, the strength of aramid yam decreases fastest, a slight decreases for PTFE yarns and remains unchanged for basalt yarn. Collusion intensity retention of PTFE yarn is obviously higher than that of other yarns, which represents a superior bending resistance： Initial decomposition temperature of three yarns is above 500 ℃. However, when the temperature exceeds 500 ℃ , PTFE yam and aramid yarn decompose rapidly but basalt yam has the least thermo-gravimeter loss.