VISCOELASTIC PROPERTIES OF PET AND NYLON CORD YARNS

In paper viscoelastic properties of commercially available polyester (PET) and nylon (PA 66) cord yams are discussed and compared. The upon mentioned behavior was evaluated via the analysis of stress-strain, as well as dynamic mechanical properties. On the basis of viscoelastic analysis significantly different viscoelastic behavior of PET and PA 66 cord yams can be clearly seen. From the stress-strain curve it can be clearly seen that modulus of elasticity of PET cord yams is higher compared to PA 66 cord yams elasticity modulus. On the contrary the dynamic mechanical properties such as Storage Modulus E' and Loss Modulus E '' of PA 66 are higher compared to PET Storage Modulus E' and Loss Modulus E" which can be a consequence of higher orientation of PA 66. Tan delta and dumping properties of the two cord yams were considered to be comparable, whereas the creep behavior of PET was considered to be less noticeable (more stable material) and its properties were not changing much if compared to PA 66 in the temperature range in which the cord yams were analyzed.