Classification of polyester filament
Classification by production method
1. Primary yarn: polyester undrawn yarn (conventional spinning) (UDY), polyester semi-pre-oriented yarn (medium-speed spinning) (MOY), polyester pre-oriented yarn (high-speed spinning) (POY), polyester high-orientation Silk (Ultra High Speed Spinning) (HOY).
2. Drawing yarn: polyester drawn yarn (low-speed drawing yarn) (DY), polyester full drawn yarn (spinning and drawing one-step method) (FDY), polyester full-drawing yarn (spinning one-step method) (FOY) .
3. Textured yarn: polyester conventional textured yarn (TY), polyester stretch textured yarn (DTY), polyester air textured yarn (ATY).
Classification by use
Mainly divided into civil and industrial use.
Classification by TiO2 content in polymers
Polyester filament yarn itself is shiny, if you need to eliminate the gloss to adapt to the production of subsequent textiles and industrial products, you need to add TiO2 in the production process
| polyester filament luster | TiO2 content |
| Super glossy polyester filament | 0 |
| Bright polyester filament | 0.1% |
| Semi-matte polyester filament | 0.3-0.5% |
| Fully matte polyester filament | ≥ 2.5% |
Classified by DPF ( fineness of individual fiber )
| Classification | Monofilament fineness (d) | Diameter (μm) | use |
| Ordinary polyester filament yarn | 1.5~6 | 12~25 | General clothing, decoration, industrial materials |
| Fine polyester filament yarn | 0.6~1.4 | 8~12 | Soft cloth, high density woven fabric |
| Superfine polyester filament yarn | 0.1~0.6 | 0~8 | Artificial leather, wipes, etc. |
| Ultimate Fine Polyester Filament Yarn | Below 0.1 | 3 or less | medical materials, etc. |
Properties of Polyester Filament Yarn
(1) Initial modulus
The initial modulus, or modulus of elasticity, refers to the stress required when a fiber is stretched to 1% of its original length. Polyester filament yarn for civil use is not less than 90 CN/dtex, and polyester filament yarn for industrial use can reach 132.5 CN/dtex, while nylon 66 yarn is only 35 CN/dtex and 44 CN/dtex respectively, and at temperature (dry or When the steady state) increases, the modulus of polyester yarn is better than that of nylon yarn. Therefore, the initial modulus of polyester filaments is considered to be an important determinant in the application of polyester fibers.
(2) Strength
Polyester filament yarn has high strength (about 4.5~8 CN/dtex), which can meet the requirements of most clothing and industrial applications. And its retention strength in 95 ℃ water reaches 73%, while nylon filament yarn is only 51%.
(3) Elasticity
The elasticity of polyester filament is not as good as that of nylon filament. For example, the elastic recovery rate under 2% tension is 96%, and the elastic recovery rate of nylon filament under the same conditions is 98%. However, it should be pointed out that due to the higher initial modulus of polyester filament, its Dimensional stability is particularly good.
(4) Wrinkle recovery
Although the elastic recovery rate of polyester filament yarn is not too high, the recovery rate of polyester fabrics against undesired wrinkles is very high.
(5) Toughness
Compared with nylon, the elongation at break of polyester is relatively low, so that the toughness of polyester filament has low energy absorption performance and wear resistance.
(6) Absorption of water
Polyester filament yarn is poor in this regard, both in terms of moisture regain in humid air and water expansion; the equilibrium moisture content is 0.4%, which is worse than nylon filament yarn and similar to acrylic.
(7) Shrinkage
Polyester fabrics carry water with little or no shrinkage, especially after proper heat setting, and can maintain shrinkage requirements within 1%.
(8) Density
The density of polyester is close to 1.38g/m3, which is higher than that of nylon (1.14g/cm3) and polypropylene (0.90g/cm3)
(9) Resistivity
The resistivity of polyester is higher than that of nylon, generally 1011-1014 ohm/cm, and nylon is 109-1014 ohm/cm.
(10) Pilling
Fiber balls are created due to loose and broken monofilaments in the fabric. Because of the high strength of the fibers, the fiber balls are retained on the fabric. Polyester yarn manufacturers have recently produced low tensile strength polyester filament yarns that are less prone to balling, which also maintains high abrasion resistance.
(11) Glass transition temperature
The glass transition temperature of polyester filament yarn in dry state is 80°C. This secondary feature is beneficial for yarn crimping and texturing, fabric heat setting and fabric pleating.
| fiber type | polyester | Nylon 6 | Nylon 66 | polypropylene |
| Melting point (℃) | 265 | 220 | 265 | 168 |
| Glass transition temperature (℃) | 80 | 40 ~ 87 | 50 ~ 90 | - 17 |
| Density (g/cm3) | 1.380 | 1.13 | 1.14 | 0.91 |
| Water absorption %: 24hrs | 0.09 | 1.9 | 2.8 | 0 |
| Water Absorption %: 14Days | 0.49 | 9.5 | 8.9 | < 0.03 |
Table 1. Comparison of physical properties of polyester, nylon and polypropylene
Quality Standard of Polyester Filament (Physical Index)
1) Linear density.
2) Breaking strength.
3) Elongation at break.
4) Unevenness rate.
Evenness is an indicator that expresses the evenness of filament evenness, expressed by cv value (coefficient of variation) or (U) value (Uster%). The international standard uses CV values. There are three test methods for Cv value, namely Normal method, In-ert method and 1/2Inert method, and Normal method is usually used. This indicator is particularly important for polyester pre-oriented yarns and polyester drawn-textured yarns . If the polyester filament is not evenly dry, it is easy to produce wool and uneven dyeing during processing.
5) Shrinkage in boiling water.
6) Dyeing uniformity
Dyeing uniformity is an important quality index of polyester filament yarn. Dyeing uniformity of textured yarn: The dyeing uniformity of each yarn package shall be determined. The "Ministry of Industry Standard" adopts gray carding, etc., and is divided into 5 grades and 9 grades. The higher the grade, the more uniform the dyeing performance.
7) Curl shrinkage and crimp stability.
8) Oil content.
9) Full cylinder rate.
Application of polyester filament
Polyester filament yarn has a wide range of uses, and is widely used in the manufacture of clothing and industrial products.
Polyester is used as a fiber for clothing, and its fabrics are wrinkle-free and iron-free after washing. Polyester is often blended or interwoven with various fibers, such as cotton polyester, wool polyester, etc., and is widely used in various clothing and decorative materials. Polyester filament yarn can be used for conveyor belts, tents, canvas, cables, fishing nets, etc. in industry, especially polyester cords for tires, which are close to nylon high tenacity yarn in performance . Polyester filament yarn can also be used for electrical insulating materials, acid-resistant filter cloth, medical industrial cloth, etc. Synthetic fibers have been widely used in various fields of the national economy due to their high strength, wear resistance, acid resistance, alkali resistance, high temperature resistance, light weight, warmth, good electrical insulation and no fear of mildew.
In the early days, polyester filament was mainly used in silk clothing. With the development of various processing technologies, polyester filament has been expanded to the entire clothing field such as wool-like, linen-like, and cotton-like, and has also been used in decoration, industry and non-fiber fields. develop. Especially in Japan, new synthetic fibers made of polyester filaments have recently become popular in the clothing industry. The so-called new synthetic fibers are synthetic fibers that are new, unique and surpass any natural fiber style and feel. It has changed people's concept of dressing, and has risen from warmth and beauty to comfort, health, novelty and artistry. Thereby making the use of polyester filament more extensive.
(1) For clothing
The traditional use of polyester filament is to imitate silk for women's shirts, men's and women's outerwear, skirts, pajamas and scarves. The fine and special filaments are strongly twisted before being deformed, and can be made into soft imitation silk, which is suitable for high-end dresses and "grandma shirts" worn by middle-aged and elderly women. Coarse textured yarn can be made into wool-type fabrics for suits, outerwear and ties, but the dimensional stability of its knitted fabrics is not ideal. Blended yarns are mainly used in men's clothing, children's clothing and sportswear.
(2) Bedding
Polyester filaments are used as quilt covers, pillowcases, bed sheets, bedspreads, mosquito nets, tablecloths and cotton wool.
(3) For decoration
Polyester filament is used as sofa cloth, furniture cloth, curtain cloth, window screen cloth, wall cloth, carpet, poncho, umbrella cloth and car interior decoration cloth, etc.
(4) Industrial use
Polyester filaments are used as sewing threads, cords, conveyor belts, canvas, geotextiles, filter cloths, tents, nets and ropes, etc.
(5) For non-fibrillation
Synthetic suede made of microfiber polyester filament used for fur coats, jackets, women's tops, etc.
(6) Field of protective clothing
Because of its flame retardancy, flame retardant polyester has a wide range of applications. In addition to its irreplaceable role in industrial textiles, building interiors, and vehicle interior decoration, it also plays a lot of roles in the field of protective clothing. According to the national standards for flame retardant protective clothing, metallurgy, forestry, chemical, petroleum, fire protection and other departments should use flame retardant protective clothing. The number of people who should use flame retardant protective clothing in China is more than one million, and the market potential of flame retardant protective clothing is huge. In addition to pure flame-retardant polyester filament, we can produce multi-functional products such as flame-retardant, waterproof, oil-repellent and anti-static according to the special requirements of users. For example, the waterproof and oil-repellent finishing of flame retardant polyester fabric can improve the functionality of flame retardant clothing; flame retardant polyester and conductive fibers are interwoven to produce antistatic flame retardant fabrics; flame retardant fibers and high-performance fibers are used for blending and interweaving , which can produce high-performance flame-retardant fabrics; flame-retardant fibers are blended with cotton, viscose and other fibers to improve the comfort of protective clothing and reduce secondary burns.
