The impact of yarn input tension upon the structure and relaxation of plain jersey weft knitted fabrics
The impact of input tension of elastane and cotton yarns upon the structure and relaxation of plain jersey knitted fabrics is investigated. There are considerable differences in the behaviour of conventional knitted fabrics and the fabrics with elastane yarns incorporated in the structure. One of the key factors in knitting is certainly the input tension of the yarn, as it impacts the structure and properties of such knitted fabrics. Horizontal and vertical density, as well as surface mass grows with the prolonged relaxation period as they grow with the increase of knitting yarn input tension. Increase in knitting yarn input tension reduces the length of the yarn in the loop. If cotton yarn is platted with elastane one, the length of the yarn in the loop is reduced for about 2 to 5%, as compared with the yarn in a course without the elastane yarn. This can result in horizontal streaks in the knitted fabric. The most prominent dimensional changes in the direction of the courses and wales occur with the samples knitted with the highest input tension on knitting yarns. The best results of measuring structural parameters and dimensional changes in knitted fabrics in relaxation have been exhibited by knitted samples with the lowest input tension. In constructing knitted fabrics input tension of the yarns should be taken into account, as it considerably affects fabric properties.