This paper proposes a comparative study of the tensile behaviour of the knitwear under linen made of 100% cotton yarn in 1:1 rib with Nm 50/1 and 2:2 rib with Nm 40/1. The rib structures 1:1 are more dimensionally stable than the rib structures 2:2, on both directions, due to the higher number of yarn-yarn contact points and due to the distribution of the rib platinum loop. The studies made on the proposed structures have demonstrated that it can be obtained an almost identical dimensional stability, which fits in the limits ±2, if for the rib structures 2:2 thicker yarns are being used. After knitting and finishing, the structure parameters of the knits are determined and then they are subjected to the tensile strength, and the result after processing the obtained data, it is concluded that the behaviour of the knits at the tensile stresses is comparable to the real situation. The study is carried out on both directions of the knits, in the horizontal direction, of the rows of meshes and in the vertical direction of the strings. The performance-elongation diagrams are represented through graphics and the results obtained are interpreted, the data being used to determine the structure parameters of the knits in order to obtain maximum dimensional stability at wearing.

The paper proposes a study regarding the dimensional changes during washing process for the 1:1 interlock structures made of 100% cotton yarn with Nm 58/1. The interlock 1:1 structures which are studied are made of 100% cotton yarns, with Z torsion, on Monarch circular knitting machines, with diameter of 30 inch, fineness 20E and 72 knitting systems. Tubular meterage knitwear resulted from this process. After the knitting, the structures were laid for relaxation, and then they were subjected to the washing, drying and relaxation operation. The loosening of the knits for 72 hours was done in air-conditioned areas respecting the parameters of the standard atmosphere to balance the internal tensions introduced into the structures during the knitting and washing operations. The structure parameters of the knitwear modify after the relaxation before finishing process, after finishing and after washing process. The machines where the structures were produced are new generation knitting machines and finishing. After knitting and relaxation of the fabrics, the finishing and washing processes were applied with a minimum tension of the structures, de-watering was made with uniform pressure air-blowing installations on entire length and surface of the tubular knitting, in this way replacing the classical centrifugation machines, which had a dynamic action on knitwear and increased the wrinkling.