Performance Properties of Aramid and Hybrid Aramid Cord Yarns Based on Rusar® Fiber

Abstract

A study of the performance properties of aramid Rusar-75, Rusar-175 and hybrid Rusar-75K, Rusar-175K cord threads has been carried out. It is shown that strands of hybrid cord threads, including aramid thread Rusar 58,8 tex and nylon 93,5 tex, have different linear shrinkage. During heat treatment, visual defects in the form of loops are formed on hybrid threads, at the same time, Rusar-75 and Rusar-175 aramid threads do not shrink, but lengthen by 1,0–1,5 % and do not have visual defects. It has been established that the defect formation of a thread due to different shrinkage of nylon and aramid cannot be eliminated in the process of impregnation and rubberizing. Therefore, despite a significant increase in the adhesive characteristics of hybrid yarns from the addition of nylon, after rubberizing and vulcanization, the delamination strength in model rubber-cord samples with Rusar-75 is 10 % higher than the strength in model samples with Rusar-75K.
It is shown that the use of hybrid aramid-nylon yarn as a reinforcing filler in rubber technical products is impractical.