The analysis of air-jet textured polyester/polyester and polyester/polytetrafluoroethylene sewing threads'

Of late years, the assortment of sewing threads dramatically increased, due to appearance of new fibres, new processes (or improved old ones) to produce new type of threads, increased demand for sewing threads, intended for different type of fabrics.If we compare the domination of different air-textured threads, in a dominating position we will find polyester. Because, in comparison with non-textured yarns, they show increased bulkiness, porosity, softness, comfort and air permeability. The products of textured yarns are noted for good draping qualities, therefore they are used in sportswear, home and apparel fabrics.The aim of this research was to assess how certain mechanical characteristics of sewing threads varied while different parameters were changed during the manufacturing process.Air-textured technical sewing threads are relatively new products on the market. The applications of the end product could be selected depending on the mechanical characteristics of the product during usage. Some applications require very high tenacity, other require very low friction forces during the sewing process.Air texturing appears to be a technology which can accommodate the manufacturing possibilities of threads with different end char¬acteristics and also allow the usage of different types of fibre filaments. Two types of yarns were manufactured during this research: high tenacity PES yarns were used in both core and sheath elements in one case; in the other case, the same high-tenacity PES yarns were used in the core while Polytetrafluorethylene (PTFE) was used in the sheath elements. The threads were manufactured in the Department of Textile Technology at Kaunas University of Technology, using a Stahle Eltex air-texturing machine and a Heberlein HemaJet texturing nozzle. In addition, tensile and friction tests were performed during the research. Different manufacturing parameters were changed during air-texturing, including air pressure and overfeeds of effect & core yarn. The results clearly showed the good mechanical character¬istics of the sewing threads manufactured.