Introduction of Polyester Yarn
Polyester yarn is an important variety of synthetic fiber yarn. It is esterified or transesterified with purified terephthalic acid (PTA) or dimethyl terephthalate (DMT) and ethylene glycol (EG) as raw materials. Polyethylene terephthalate (PET), a fiber-forming polymer obtained by polycondensation and polycondensation, is a yarn made by spinning and post-processing.
Polyester yarn has a wide range of uses and is widely used in the manufacture of clothing fabrics and industrial products. Polyester yarn has excellent setting properties. After the polyester yarn or fabric is set, the flat, fluffy shape or pleats, etc., can be washed for many times in use, and it will remain unchanged for a long time.
Polyester yarn is the simplest of the three synthetic fiber yarns, and the price is relatively cheap. In addition, it has the characteristics of strong and durable, good elasticity, not easy to deform, corrosion resistance, insulation, crisp, easy to wash and quick dry, etc., which is loved by people.
Characteristics of polyester yarn
Polyester yarn has high strength, good elasticity, heat resistance, heat insulation, abrasion resistance and corrosion resistance.
The tenacity of polyester staple fiber is 2.6 – 5.7 cN/dtex, and the tenacity of polyester high tenacity fiber is 5.6 – 8.0 cN/dtex. Due to the low hygroscopicity of polyester yarn, its wet strength is basically the same as its dry strength. The impact strength is 4 times higher than that of nylon yarn and 20 times higher than that of viscose fiber yarn.
The elasticity of polyester yarn is close to that of wool, and when stretched by 5% – 6%, it can almost fully recover. The wrinkle resistance of polyester yarn exceeds that of other fiber yarns, that is, polyester-containing fabrics do not wrinkle and have good dimensional stability. The elastic modulus of polyester yarn is 22 – 141cN/dtex, which is 2 to 3 times higher than that of nylon yarn.
Polyester yarn is made by melt spinning method, and the formed polyester fiber can be heated and melted again, which belongs to thermoplastic fiber. The melting point of polyester fiber is relatively high, and the specific hot air and thermal conductivity are small, so the heat resistance and thermal insulation of polyester yarn are higher, which is the best among synthetic fiber yarns.
The surface of polyester yarn is smooth, and the internal molecules are closely arranged.
good wear resistance
The abrasion resistance of polyester yarn is second only to nylon yarn with the best abrasion resistance, and it is better than other natural fiber yarns and synthetic fiber yarns.
Good light fastness
The light fastness of polyester yarn is second only to acrylic yarn.
Polyester yarns are resistant to bleaches, oxidants, hydrocarbons, ketones, petroleum products and inorganic acids. It is resistant to dilute alkali and not afraid of mildew, but hot alkali can make it decompose. Polyester yarn also has strong acid and alkali resistance and UV resistance.
Polyester yarn has poor dyeability, but has good color fastness and is not easy to fade. Because there is no specific dyeing group on the polyester molecular chain, and the polarity is small, it is difficult to dye, the dyeability is poor, and the dye molecules are not easy to enter the fiber.
Poor water absorption
Polyester yarn has low water absorption and moisture regain and good insulation performance, but due to low water absorption, large static electricity generated by friction, and poor dyeing performance.
The fabric woven from ordinary polyester filament yarn has the advantages of good strength, smoothness and stiffness, easy washing and quick drying, etc., but it has disadvantages such as hard hand, poor touch, soft luster, poor air permeability and hygroscopicity. Compared with silk fabrics, the gap is even greater, so silk must first be simulated on the silk thread structure to eliminate the disadvantage of poor wearing performance.
Classification of polyester yarn
The varieties of polyester yarn include staple fiber, drawn yarn, textured yarn, decorative filament, industrial filament and various differentiated fibers.
polyester staple fiber
1. According to physical properties: high-strength and low-stretch type, medium-strength and medium-stretch type, low-strength and medium-stretch type, high-modulus type, high-strength and high-modulus type
2. According to post-processing requirements: cotton type, wool type, linen type, silk type
3. According to the use: clothing, cotton, decorative, industrial
4. Distinguish by function: cation dyeable, hygroscopic, flame retardant, colored, anti-pilling, antistatic
5. According to the fiber cross section: special-shaped wire, hollow wire.
Polyester Filament Yarn
1. Primary yarn: undrawn yarn (conventional spinning) (UDY), semi-pre-oriented yarn (medium-speed spinning) (MOY), pre-oriented yarn (high-speed spinning) (POY), high-oriented yarn (ultra-high-speed spinning) spinning) (HOY)
2. Drawing yarn: drawing silk (low-speed drawing silk) (DY), full drawing silk (spinning and drawing one-step method) (FDY), full-drawing silk (spinning one-step method) (FOY)
3. Textured yarn: conventional textured yarn (TY), stretch textured yarn (DTY), air textured yarn (ATY).
Application of polyester yarn
Polyester yarn is used as clothing yarn, and its fabric can achieve the effect of no wrinkle and no ironing 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 yarn can be used for conveyor belts, tents, canvas, cables, fishing nets, etc. in industry, especially polyester cord used for tires, which is close to nylon yarn in performance. Polyester 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 retention, good electrical insulation and resistance to mildew.
In the early days, polyester yarn was mainly used in silk clothing. With the development of various processing technologies, polyester yarn has been expanded to the entire clothing field such as wool-like, linen-like, and cotton-like, and has developed to the fields of decoration, industry and non-fiberization. Especially in Japan, new synthetic fibers made of polyester yarns have recently become popular in the clothing industry. The so-called new synthetic fibers are synthetic fibers that have a new, unique style and feel that surpasses any natural fiber. It has changed people’s concept of dressing, and has risen from warmth and beauty to comfort, health, novelty and artistry. Thereby, the use of polyester yarn becomes more extensive.
The traditional use of polyester yarn is to imitate silk for women’s shirts, men’s and women’s outerwear, skirts, pajamas and scarves. Polyester fine extra-long yarn is strongly twisted before being deformed to make soft imitation silk, which is suitable for high-end dresses and clothes worn by middle-aged and elderly women. Polyester coarse and special textured yarn can be made into wool fabric for suits, outerwear and ties, but the dimensional stability of its knitwear is not ideal. Blended yarns are mainly used in men’s clothing, children’s clothing and sportswear.
For bed linings
Polyester yarn is widely used in quilt covers, pillowcases, bed sheets, bedspreads, mosquito nets, tablecloths and cotton wool.
Polyester yarn is widely used in sofa cloth, furniture cloth, curtain cloth, window screen cloth, wall cloth, carpet, poncho, umbrella cloth and car interior decoration cloth.
For Industrial use
Polyester yarns are widely used in sewing threads, cords, conveyor belts, canvas, geotextiles, filter cloths, tents, nets and ropes.
For Protective clothing field
Because of its permanent flame retardancy, flame retardant polyester yarn has a wide range of applications, in addition to industrial textiles, building interior decoration, and vehicle interiors.
In addition to playing an irreplaceable role in decoration, it also plays a lot of roles in the field of protective clothing. 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.