Introduction to Polyester Staple Fiber

Polyester staple fiber (PSF), commonly referred to as staple fiber, is produced by polymerizing PTA (purified terephthalic acid) and ethylene glycol to form polyester (PET), which is then melt-spun, stretched, and cut into short fibers. Since its introduction to China in the 1970s, PSF has flourished in the market due to its wide applicability and cost-effectiveness, becoming an essential raw material in industries such as textiles, apparel, and home furnishings.

Raw Materials and Production Processes

Classification of Staple Fiber

PSF, a crucial raw material in textiles, apparel, and home furnishings, can be categorized into different types based on various classification criteria. It is primarily divided into virgin staple fiber and recycled staple fiber.

• Virgin staple fiber, also known as "large chemical fiber" in China, is made from PTA and ethylene glycol through polymerization, spinning, and cutting processes.

• Recycled staple fiber, often called "small chemical fiber," is produced from recycled PET bottles, which undergo drying, melting, spinning, and cutting.

Production Processes of Virgin Staple Fiber

Virgin staple fiber can be further classified based on spinning methods, with the most common being melt direct spinning and batch spinning (chip spinning).

• Melt direct spinning is a widely used process where PTA and ethylene glycol are polymerized into polyester melt, which is then directly spun and cut into staple fiber. This method dominates conventional PSF production in China.

• Batch spinning (chip spinning) uses PET chips as raw material. Compared to melt spinning, this process includes additional steps such as chip drying and melting, but the subsequent spinning and cutting stages remain similar.

Downstream Applications

Three Major Application Categories

PSF is primarily used in three downstream sectors: spinning & thread-making, filling materials, and non-woven fabrics.

• Spinning & thread-making is the core application, covering both cotton spinning (e.g., pure polyester yarn, polyester-cotton blends, polyester-viscose blends, and sewing threads) and wool spinning (e.g., polyester-acrylic blends, polyester-wool blends, and blanket production).

• Filling materials, often made from hollow polyester fibers, provide warmth in home furnishings and apparel, including bedding, winter coats, sofa cushions, and stuffed toys.

• Non-woven fabrics have seen rapid growth, with applications such as spunlace non-wovens (used in wipes and medical products) and geotextiles, synthetic leather base fabrics, and roofing felts for industrial uses.

Market Dominance of Spinning-Grade PSF

In the market, spinning-grade polyester staple fiber holds the largest share, with virgin PSF being the most widely used in yarn production.