Views: 0 Author: Site Editor Publish Time: 2025-08-28 Origin: Site
The production process of polyester filament can be divided into conventional spinning process, medium-speed spinning process, and high-speed spinning process according to the spinning speed.
一.、Conventional spinning process
Conventional spinning, also known as low-speed spinning, is the earliest industrial production process. It adopts a three-step process route of spinning, winding, stretching, and twisting (UDY-DY-TY). The spinning speed is 1000-1500m/min, the stretching and twisting speed is 600-1100m/min. The false twisting and deformation speed is 120-160m/min, and the post-processing draw ratio is 3.5-4.2 times (before false twisting and deformation processing). It can produce 33-167dtex filament.
Conventional spinning can produce both stretched yarn and textured yarn. Its characteristics include mature technology, stable equipment operation, easy-to-master technology, good product quality, and good dyeing uniformity. The textured yarn M (M yarn is a normal dyed yarn whose color absorption differs from that of the standard textured yarn by within half a grade) can reach 96%. However, the process flow is long and the production efficiency is low.
二、Medium-speed spinning process
Medium-speed spinning is a two-step process. The spinning speed is 1800~2500m/min, producing semi-pre-oriented yarn (MOY). There are two process routes for medium-speed spinning.
1. MOY-DY process
This process adopts medium-speed spinning and low-speed stretching. The spinning speed is 1800~2500m/min, and the stretching and twisting speed is 800~1200m/min, capable of spinning stretched yarns with a fineness of 33~167dtex, commonly 75dtex and 50dtex. Its production efficiency is lower than high-speed spinning, and the product quality is worse than conventional spinning.
2. MOY-DTY process
This process adopts medium-speed spinning and high-speed stretching deformation. The remaining stretching multiple of MOY is 2.1 to 2.4 times, the stretching deformation speed is 400 to 500 m/min, and it can produce 55 to 88 dtex textured yarn. When exceeding 110 dtex, two yarns need to be combined into one bobbin. The production efficiency and product quality of this process are inferior to the POY-DTY process.
三、High-speed spinning process
The spinning speed of high-speed spinning is 3000~3600m/min, which can produce pre-oriented yarn (POY). There are three process routes for high-speed spinning.
1. POY-DTY process
This process adopts high-speed spinning, high-speed stretching and deformation, which is a typical two-step process route and is currently the most widely used process route for producing textured yarns.
The post-processing speed of POY is usually 400~800m/min, capable of spinning 50~167dtex textured yarn (DTY). Its characteristics include a short process flow, high production efficiency, and low capital investment. POY can be stored for a long time and transported over long distances; DTY has excellent quality.
2. POY-TY process
This process uses high-speed spinning and low-speed false twisting deformation (rotor false twisting method) to produce textured yarns with a fineness of 111 to 167 dtex. This process route is economically and technically unreasonable.
3. POY-DY process
This process uses high-speed spinning and low-speed stretching and twisting to produce 55~110dtex stretched yarn. The stretching ratio is 1.3~1.7 times, using a general stretching and twisting machine. The DY performance obtained from this process is not as good as UDY.
四、One-step spinning and drawing process
This process adopts two procedures of spinning and stretching to be completed on a spinning and stretching integrated machine, which is a one-step process route. There are two production processes: one is with a spinning speed of 900~1500m/min, a stretching speed of 3200~4000m/min, a stretching ratio of 3.5 times, and can produce 55~165dtex stretched yarn; the other has a spinning speed of 2600~3500m/min and a stretching speed of 5100~5500m/min. The long filament produced by this process is called FDY.
五、Other spinning processes
In addition to the above, the production process of polyester filament also includes high-orientation yarn (HOY) production process and high-crystallinity yarn (HCY) production process.
High Orientation Yarn (HOY), also known as Fully Oriented Yarn. This process uses a one-step ultra-high-speed spinning method, with a spinning winding speed of 5500–6000 m/min. Due to a significant increase in nozzle drawing, the fiber's orientation degree is greatly improved, but the crystal grains are large, the amorphous region orientation degree is relatively low, the fiber's dyeing performance is good, but the elongation is too large (about 40%), even if the winding speed is increased to 7000–8000 m/min, the elongation still does not meet general wear requirements, and it is currently still in the experimental production stage.
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