Production Process of Polyester Yarn

Raw Materials and Preparation

Polyester yarn, a fiber made from polyester through a spinning process, is typically derived from polyethylene terephthalate (PET), which is widely known by its English abbreviation "PET." In China, this fiber is commonly referred to as "涤纶" (dílún). Through the spinning process, polyester staple fibers can be transformed into pure polyester yarn. These staple fibers come in various types, differing in length and thickness. For example, cotton-type fibers are approximately 37 mm in length, while wool-type fibers can range from 75 to 105 mm.

Fiber Selection and Its Impact

During the spinning process, the thickness and length of the fibers directly affect the quality of the final product. Generally, fine-denier fibers (around 1.5D) are suitable for producing delicate yarns, whereas coarse-denier fibers (around 5D) have a rougher texture but a stronger wool-like feel. Additionally, the origin of the fibers must be considered during spinning to ensure the quality and consistency of the yarn.

Types and Characteristics of Polyester Yarn

Full-Bright vs. Semi-Dull Polyester Yarn

Full-bright polyester yarn has a smooth fiber surface, giving the woven fabric a glossy appearance. In contrast, semi-dull polyester yarn undergoes further chemical treatment—alkali reduction—to achieve a matte effect. This process takes advantage of polyester's sensitivity to strong alkalis, such as sodium hydroxide, which creates fine cracks on the fiber surface, resulting in a dull finish. Fabrics made from semi-dull polyester yarn have an elegant and sophisticated look, making them highly popular in the market. Alternatively, physical or chemical methods can be applied during fiber production to roughen or crack the fiber surface, achieving a similar fabric reduction effect as semi-dull polyester yarn.

Comparison Between Polyester Yarn and Other Fibers

Polyester yarn, as a crucial raw material for weaving, stands alongside traditional materials such as cotton yarn, rayon, nylon yarn, wool yarn, and linen yarn. It is a synthetic fiber with the scientific name polyethylene terephthalate (polyester). This fiber has almost no moisture absorption (a moisture regain rate of only 0.4%, compared to 8.5% for cotton yarn), making fabrics made from it easy to wash, quick to dry, stiff yet durable, and resistant to wrinkling. However, in terms of comfort, it falls slightly short compared to certain natural fibers.