No abstract

In this article, the draw ratio of elastic core yarn (Spandex filament 44 dtex/f4) was regulated from 2.7 to 4.41 (i.e., 2.7, 3.22, 3.49, and 4.41) by using a developed positive feed drive and a microcontroller system. The elastic core positioning (left, center, and right) in front roller nip of ring frame was also changed using a standard V-groove guide roller. The physical properties of produced yarns including tensile properties, hairiness, irregularity, and fibre covering were investigated and compared. The results revealed that at 3.49 draw ratio, the maximum elastic core-spun yarn tenacity and elongation and minimum S3 hairiness values were obtained compared with 2.7 and 4.41 draw ratios. The results indicated that increasing the elastic yarn draw ratio increased the elastic core-spun yarn irregularity and fibre-covering factor by which the highest values were obtained at 4.41 elastic yarn draw ratio. It was also found that elastic yarn positioning at the left edge of roving ribbon deteriorated core-spun yarn evenness while elastic yarn positioning at the center of the roving ribbon improved the core-spun yarn hairiness. However, elastic yarn positioning has no significant effect on elastic core-spun yarn tensile and fibre-covering properties.

No abstract

In this article, a new higher order shear deformation theory based on trigonometric shear deformation theory is developed. In order to consider the size effects, the nonlocal elasticity theory is used. An analytical method is adopted to solve the governing equations for static analysis of simply supported nanoplates. In the present theory, the transverse shear stresses satisfy the traction free boundary conditions of the rectangular plates and these stresses can be calculated from the constitutive equations. The effects of different parameters such as nonlocal parameter and aspect ratio are investigated on both nondimensional deflections and deflection ratios. It may be important to mention that the present formulations are general and can be used for isotropic, orthotropic and anisotropic nanoplates.968

No abstract