Polyester Staple Fiber
Polyester fiber is a man-made fiber produced by condensation polymerization of monoethylene glycol (MEG) and terephthalic acid (PTA) or dimethyl terephthalate (DMT), forming a polymer called polyethylene terephthalate (PET). The fibers are either manufactured in a single-step continuous polymerization process or in a batch process, termed as chip-spinning, where the fiber-grade chips are first produced through the above polymerization process and then melted to produce the polymer in molten form. The molten polymer produced through continuous polymerization or chip-spinning routes is filtered and extruded through a spinneret having a number of micro holes. The hot melt coming out from the spinneret holes is cooled and solidified into continuous filaments. These solidified filaments are immediately collected and either wound onto bobbins as continuous filaments or further drawn and cut into short cut-lengths. The continuous filaments are either partially oriented yarns (POY) or fully drawn yarns (FDY). The fibers in short cut-lengths are termed as polyester staple fibers (PSF). The majority of polyester filament yarns (PFY) are further textured to produce drawn textured yarns (DTY), which are then ready to be woven or knitted in fabric. Staple fibers are processed further to convert to spun yarn either as 100% polyester spun yarns or in blends with other fibers, such as cotton, viscose, acrylic, or wool. Spun yarns are then woven or knitted to form fabrics. The other method to produce fabric from staple fibers is through a nonwoven process wherein the polyester staple fibers are bonded together to form nonwoven fabric through different bonding processes, such as thermobonding, needle punching, air through bonding, and hydroentanglement.