In the world of textiles, various types of yarns are used, each with its own unique characteristics. Two commonly used yarn types are POY (Partially Oriented Yarn) and FDY (Fully Drawn Yarn). Understanding the differences between them is crucial for making informed decisions in textile manufacturing and applications.
1. Production Process
POY
POY is produced through a high - speed spinning process. In this process, the molten polymer is extruded through spinnerets, and then rapidly cooled and drawn at high speeds. However, the drawing process is only partial. The yarn has an intermediate level of molecular orientation, which gives it a certain degree of strength and elongation, but it is not fully oriented like FDY. After spinning, POY is usually wound onto bobbins and requires further processing, such as texturing or drawing - texturing, to obtain the desired properties for specific applications.
FDY
FDY is produced through a combination of high - speed spinning and a subsequent drawing process. After the polymer is extruded and initially formed into a yarn, it undergoes a continuous drawing operation. This drawing process orients the polymer molecules more fully, resulting in a yarn with higher strength, lower elongation, and better dimensional stability. The entire process from spinning to drawing is carried out continuously, and FDY can be directly used for weaving or knitting without the need for additional major drawing steps in most cases.
2. Physical Properties
Strength and Elongation
POY has relatively lower strength compared to FDY. Due to its partial orientation, it can be stretched further during subsequent processing. It typically has a higher elongation at break, which means it can be extended more before breaking. This property makes it suitable for processes where additional stretching and texturing are required to create bulk and elasticity in the final fabric.
On the other hand, FDY has higher strength because of the full orientation of its polymer molecules. The lower elongation at break indicates that it does not stretch as much as POY. FDY's stable physical properties make it ideal for applications where a more rigid and dimensionally stable fabric is needed.
Appearance
POY yarn often has a relatively smooth surface, but because it is not fully drawn, it may appear slightly less lustrous compared to FDY. FDY, with its highly oriented structure, usually has a smoother and more lustrous appearance. The full drawing process aligns the fibers better, resulting in a more uniform and shiny surface, which is beneficial for applications such as making high - quality apparel fabrics.
3. Applications
POY
Since POY can be further processed, it is commonly used in the production of textured yarns. Textured POY yarns are widely used in the manufacturing of knitted and woven fabrics for clothing, upholstery, and carpets. For example, in sportswear, textured POY - based fabrics can provide the necessary stretch and comfort. In carpets, the textured yarns made from POY can create different pile heights and textures, enhancing the aesthetic and functional properties of the carpet.
FDY
FDY is mainly used in applications where a high - strength, low - stretch yarn is required. It is commonly used in the production of apparel fabrics, especially for formal wear and shirts, where a smooth, stable, and wrinkle - resistant fabric is desired. FDY is also used in the manufacture of technical textiles, such as sailcloth, where the high strength and dimensional stability of the yarn are essential for the performance of the final product.
In conclusion, while both POY and FDY are important types of yarns in the textile industry, their differences in production process, physical properties, and applications make them suitable for different textile manufacturing needs. Understanding these differences allows textile manufacturers to select the most appropriate yarn for their specific products, ensuring the best quality and performance.