POY (Pre-Oriented Yarn) and PSF (Polyester Staple Fiber) represent two different polyester fiber products in the textile industry. There are obvious differences between them, which are mainly reflected in the following aspects:

1. Definition and production process
POY (Pre-Oriented Yarn): Polyester pre-oriented yarn, refers to multi-filament yarn that is only partially stretched. It is one of the main forms of polyester melt/chip spinning. In the production process of POY, the polyester melt or chip undergoes spinning, stretching and other processes, but the degree of stretching does not meet the requirements of the final product, so it is called pre-oriented yarn.
PSF (Polyester Staple Fiber): Polyester staple fiber, also known as polyester staple fiber. It is made of polyester polymer after melt spinning, and the tow undergoes further processes such as stretching, curling, spinning finishing, and then cut into fixed lengths. These cut fibers are called PSF. The length of PSF is usually similar to that of cotton fiber and is used for blending with cotton or other fibers.

2. Physical properties and uses
POY: Due to its partial stretching properties, POY is mainly used to make textured yarns, such as DTY (stretched textured yarn). At the same time, it can also be used in fabric traction warping and warp knitting processes. POY has a large deformation potential in subsequent processing and can produce a variety of yarns with special properties.
PSF: PSF is shorter in length and is usually used to blend with natural fibers such as cotton, wool, and linen or other chemical fibers to make various textiles. Due to the cost advantage and continuous improvement of polyester staple fiber performance, its share in global fiber use continues to increase, and it is widely used in clothing, home textiles, industrial textiles and other fields.

3. Morphology and structure
POY: It appears as a continuous filament with great stretching potential and deformation ability.
PSF: It appears as a short fiber with a fixed length, similar to natural fibers such as cotton fibers.
4. Industrial chain position
POY: It is usually located in the middle of the polyester fiber industry chain and is an important raw material for making various textured yarns and advanced textiles.
PSF: It is also located in the middle of the polyester fiber industry chain, but it focuses more on blending with other fibers and is an important basic material for the diversification of textiles.

POY and PSF have obvious differences in definition, production process, physical properties and uses, morphology and structure, and position in the industry chain. These differences make them play different roles in the textile industry and meet different market needs.