Spandex Yarn: elastic and innovative fiber art

Spandex yarn, also known as spandex yarn, is a special fiber with high elasticity. The elasticity of spandex yarn is its most significant feature. When stretched 2 times, the recovery rate of spandex yarn is almost 100%; even when stretched 5 times, its recovery rate is still as high as 95%-99%. This property makes spandex yarn the material of choice for making stretch fabrics, whether for sportswear, tights or underwear, where spandex yarn provides comfort and fit.

In addition to the pre-draft ratio, the percentage of spandex yarn also has a significant impact on the elasticity of the covered yarn. When the spandex yarn specifications are certain, increasing the drafting ratio will reduce the percentage of spandex yarn, that is, the pre-drafting multiple is inversely proportional to the percentage of spandex in the finished yarn. This relationship requires producers to comprehensively consider the balance between elasticity and strength when formulating process parameters.

The application of spandex yarn is not limited to single fiber form. In order to enhance its durability and functionality, spandex yarn is often wrapped in other fibers to form covered yarn. There are two main manufacturing processes for covered yarn: air coating (ACY) and mechanical coating (SCY). Air-covered yarn is made by drawing the outer fiber filament and spandex yarn at the same time, and forming rhythmic network points through high-compressed air spray pressure. The fabric feels soft and smooth. The mechanical covering yarn continuously rotates and wraps the outer fiber filament around the core spandex that is drawn at a constant speed, giving it a smooth and crisp fabric style.

Both types of covered yarns have their own advantages and disadvantages when weaving in downstream weaving mills. Air-covered yarn generally needs to be sized when warping on an air-jet loom, otherwise the fabric is prone to fluffing and broken filaments, but it can be used directly during beating-up, with high productivity and low cost. In contrast, although mechanically covered yarn does not expose the core filament and is not prone to quality problems during spinning and weaving, its output is low and the price is high, which greatly increases the cost of use. Therefore, when choosing covering yarn, producers need to make trade-offs based on specific application scenarios and cost-effectiveness.

The heat resistance and chemical resistance of spandex yarn are also important factors for its wide application. Most spandex yarns will not be damaged when stored for a short period of time at 95-150°C, but when it exceeds 150°C, the spandex yarns will turn yellow, become sticky, and lose strength. However, since spandex yarn is usually present in the fabric under the covering of other fibers, it can withstand higher heat setting temperatures (180℃-190℃), but for a shorter time. In addition, spandex yarn is resistant to most acids, alkali and chemical solvents, but some varieties have poor acid and alkali resistance, so you need to pay attention when using it.

The innovative applications of spandex yarn are also constantly expanding. For example, in the medical field, spandex yarn is used to make vascular stents with elasticity and durability; in the field of sportswear, spandex yarn is combined with nylon, polyester and other fibers to form a vascular stent with high strength, high elasticity and good breathability. of composite materials. These innovative applications not only enrich the use scenarios of spandex yarn, but also promote technological progress and industrial upgrading of the textile industry.