Polyester, as a common fiber in textiles, has always been one of the most popular categories in the fabric market. There are many types of polyester fabrics on the market, but do you really understand it?
First of all, let’s clarify the concept: What is polyester?
Polyester is an important variety of synthetic fibers and is the trade name of polyester fiber in my country. It is a fiber-forming polymer made from purified terephthalic acid (PTA) or dimethyl terephthalate (DMT) and ethylene glycol (EG) through esterification or transesterification and polycondensation reaction. —Polyethylene terephthalate (PET), a fiber made by spinning and post-processing.
Variety of polyester filament
Spun yarn: undrawn yarn (conventional spinning) (UDY), semi-pre-oriented Yarn (medium-speed spinning) (MOY), pre-oriented yarn (high-speed spinning) (POY), highly oriented yarn (ultra-high-speed spinning) (HOY)
Stretching Yarn: drawn yarn (low-speed drawn yarn) (DY), fully drawn yarn (one-step spinning and drawing method) (FDY), fully drawn yarn (one-step spinning method) (FOY)
Textured yarn: conventional textured yarn (DY), drawn textured yarn (DTY), air textured yarn (ATY)
How to identify POY and FDY?
Use your hand to pull. Generally, POY can be pulled longer, while FDY can be pulled shorter. Because POY is a pre-oriented yarn, it is not fully stretched, and the remaining elongation must be more than 50%; while FDY is a fully oriented yarn, and the remaining elongation is generally less than 40%, which is relatively stable.
The difference between FDY, DYT and POY
FDY: full pull body silk. English name: FULLDRAWYARN. Synthetic fiber filaments further produced by spinning and drawing. The fibers are sufficiently stretched and ready for textile processing.
After the yarn passes through the spinning nozzle, its elongation is stretched to less than about 3% and is no longer deformed. The appearance is smooth and non-bulky. The density of each fiber is equal. High, generally round cross-section (if the shape of the spin nozzle is not round, it will have different shapes depending on the shape of the spin nozzle), poor air permeability, and hard feel (compared to DTY), and its silk-like properties are generally used for clothing.
POY: Pre-oriented yarn. English name: PRE-ORIENTEDYARN or PARTIALLYORIENTEDYARNDTY. The winding yarn is produced at a spinning speed of more than 3000 meters/min. The orientation is higher than that of conventional spinning winding yarn, and it has a certain storage stability compared to the drawn yarn, but the crystallization is still very low.
The yarn raw material generally uses POY (the spinning process is similar to FDY, but has higher elongation), and is processed by false twisting (called deformation in mainland China) to separate the fibers of the yarn. It has a bulky cross-section and an irregular shape, better air permeability than FDY, and softer feel than FDY (generally conventional yarn types). At present, due to the development of ultra-fine and island yarn types, the main use trend is sanding. Compared with undrawn yarn, it has a certain degree of orientation and good stability, and is often used as a special yarn for drawn false twisted textured yarn (DTY).
DTY: Drawn textured yarn. Full English name: DRAWTEXTUREDYARN. Utilizing the thermoplasticity of synthetic fibers, the method of first twisting and then untwisting results in a spring-like shape, which is similar to twisting, but is actually false twist. False twist deformed yarn is commonly known as elastic yarn, and there are two types: high elasticity and low elasticity. It is made of POY as raw yarn, which is stretched and false-twisted. Often have a certain degree of elasticity and shrinkage.
·DTY: False-twisted textured yarn is called DTY (DrawTex-turedYarn), also known as stretch yarn.
·DTY network yarn: Network yarn refers to the filament in which the single filaments are entangled with each other and form periodic intersection points under the action of the jet airflow in the network nozzle. Network processing is mostly used for the processing of POY, FDY and DTY. The low-elastic network yarn produced by combining network technology and DTY technology has the fluffiness and good elasticity of deformed yarn, as well as many periodicity and network points, which improves the performance of filament yarns. The tightness eliminates several steps in textile processing and improves the ability of the tow to pass through the water-jet loom.
·POY and FDY: The spinning speed of high-speed spinning is 3000~6000m/min. The winding yarn with spinning speed below 4000m/min has a higher degree of orientation. It is pre-oriented yarn, commonly known as POY (pre-oriented yarn). If stretching is introduced during the spinning process, a wound yarn with high orientation and medium crystallinity can be obtained, which is a fully drawn yarn, commonly known as FDY (fullydrawyarn).
·DT: Stretched and twisted yarn is called DT (DrawTwist). DT can be obtained by using POY as raw yarn through a drafting and twisting machine, mainly stretching and giving a small amount of twist.
Tips:
100D/36F, 150D/36F, 50D/18F, etc. These are the expression methods of fiber specifications. The data above the diagonal line represents the fiber’s fineness. D is the fiber’s fineness unit “denier”, which is expressed in terms of the gram weight of 9000 meters of fiber under standard conditions. For example, 100 grams is 100 denier (100D); the diagonal line The data below indicates the number of holes in the spinneret used for spinning, and also indicates the number of single filaments of this specification of silk. For example, 36F means that the spinneret used during spinning has 36 holes, that is, the fiber has 36 A single filament.
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