Knit fabrics have two strands of yarn, one for the warp and one for the weft.

Update:16 Jan

Dyeing and Finishing Spandex Knitted Fabric

There are various applications for spandex knitted fabric. The content of Elastane is used to make the fabric more comfortable to wear. Lightweight Viscose/Spandex fabrics are also used for cost-effectiveness and comfort. However, there is little research focusing on the relationship between spandex consumption and fabric properties. The aim of this paper is to investigate this relationship. In particular, the consumption of Elastane in a knitted fabric determines the comfort and fit of the garment.

Knit fabrics have two strands of yarn, one for the warp and one for the weft. The result is mechanical stretch. When pulled, knitted fabrics bounce back to their original condition. 100% natural fiber fabrics are not as flexible and do not retain their shape as well as synthetics. However, knit fabrics containing spandex will stretch and keep their shape. That's why they are more comfortable and are more attractive than non-stretch fabrics.

The base material of spandex is polyurethane, a synthetic fiber. It was developed in 1937 by IG Farben in Germany. After World War II, hundreds of top German scientists emigrated to the United States. Many textile engineers from IG Farben were transferred to the DuPont Corporation, the undisputed leader in synthetic textile development during the 1940s. This material enables the manufacture of many types of garments.

The present invention relates to a process for dying and finishing bright and beautiful spandex knitted fabric. This method mainly consists of three sequential steps: the pre-treatment step determines the base color, the staining step, the dyeing step, and the finishing step. After all, the finished product is the bright, beautiful, grey cloth. The dyeing process can be performed with the Hua Shan rinsing machine manufactured in Taiwan. During the process, the fabric is soaked in a mixture of dyes, a sulphur-based softening agent, and a color-fixing agent.

The production of elastane is a very energy-intensive process. Alternatives such as renewable sources of energy can be used. But the process for polyurethane also involves some health concerns. Isocyanates are very toxic chemicals and may be absorbed through the skin, resulting in cancer or other respiratory disorders. However, these are minor concerns compared to those posed by spandex knitted fabric.

When sewing double knit fabrics, it is important to choose needles for both the fabric and the needle. A universal knit fabric needle is the best choice when sewing double knits. When sewing, use five or nine needles. Sewing on double knit fabric should have a 2.5 mm stitch length with lightly balanced tension. The stitch length should be held taught to prevent it from stretching out. The fabric is best suited for active wear.

The fabric's elasticity is one of its most important advantages. The material can stretch up to eight times its original size. Therefore, spandex is highly desirable for sportswear. It also makes comfortable, stretchy and fully form-fitting garments. The cost of pure spandex is relatively high, making it more common in other types of textiles. This is a common application of spandex knitted fabric, but you can find it in thousands of garments.