Ταξινόμηση, ιδιότητες και εφαρμογή νήματος πολυεστέρα
1: ευγενικό
In udy, the fiber molecules have no orientation; Uncrystallized: this kind of silk has low strength, long elongation and poor dimensional stability, so it can not be directly used.
Semi oriented filament (Moy), fiber molecules have a small amount of orientation, and the degree of orientation is higher than udy and lower than pre oriented filament; The structural state of this kind of silk is still not stable enough and can not be directly applied.
Pre oriented silk (POY) has been moderately stretched, has a certain degree of orientation, and has a small amount of microcrystalline particles, but it is still lower than the requirements of finished silk: this kind of silk has low strength and large elongation, so it is generally not suitable for directly processing fabrics.
High orientation yarn (Hoy) is prepared by one-step ultra-high speed spinning. The fiber has high molecular orientation and good dyeing performance, but the elongation and thermal shrinkage are large, which can not meet the general wearing requirements.
Drawing yarn (Dy), which is made by spinning and low-speed drawing, has a crystallinity of about 40 percent ; This kind of silk is straight and smooth, closely arranged with each other and poor fluffy.
Fully drawn filament (FDY), which is produced by one-step spinning and drawing method; This kind of yarn has stable quality, less wool and broken ends and good dyeing uniformity. It is an ideal yarn for high-speed weaving and processing.
Conventional textured yarn (TY) is made by three-step process of spinning winding, stretching and twisting and false twist deformation, or by high-speed spinning low-speed false twist process; It has certain elasticity and fluffy, and has good dimensional stability.
Stretch textured yarn (DTY), generally using POY as raw material, is a low elastic yarn obtained by one-step stretch texturing method; It has certain elasticity and feels less soft than ty, but its quality is stable, and its strength and elongation have met the taking requirements.
Air textured yarn (ATY), with countless small silk hoards on the surface, has the appearance of staple yarn, but there is no aurora and wax feeling like false twist textured yarn. Its covering effect and thermal insulation are similar to worsted yarn. New varieties of polyester filament include differentiated fiber, functional fiber and simulated fiber. In recent years, with the development of silk like technology, polyester monofilament has developed in the direction of fine fiber, and has been able to produce ultra{{0}}fine fibers with outlet density of 0.00011dtex.
2, Γενικές ιδιότητες των ινών πολυεστέρα
(1) Strength. The fiber strength is high, generally 4.5 8cn / dtex, and the high-strength fiber is 5.6 8 OCN / dtex, due to its poor hygroscopicity, the wet strength and dry strength are basically the same.
(2) touch amount. The initial modulus of polyester is high. The civil filament is not less than 90cn / dtex, and the industrial filament can reach 1325cn / dtex.
(3) Flexibility. The elasticity of the fiber is good, and its elastic recovery rate is 96 percent under 2 percent tension. The fabric is not wrinkled and has good dimensional stability.
(4) Good heat resistance. The melting point of polyester is 255 260 degree , heated in 150 degree air for 1000h, it changes color slightly, and the strength decreases by no more than 50 percent .
(5) Shrinkage. Polyester fabric has little or no shrinkage.
(6) Hygroscopicity. The moisture absorption of polyester is poor, and the moisture regain is only 0.4 percent , because there are few polar groups on polyester macromolecules.
(7) Pilling. Polyester is easy to pilling and not easy to fall off. This is the fiber ball caused by the loose and broken monofilament in the fabric. Because of the high fiber strength, the fiber ball is retained on the fabric. The modified polyester with low tensile strength is not easy to pilling.
(8) Dyeing. Because there are few polar groups on polyester macromolecules, it can not be dyed by general methods. With disperse dyes or non-ionic dyes, the dyeing effect is better.
(9) Flammability. Polyester burns more easily than nylon. When burning, the fiber will melt and extinguish itself.
(10) Chemical resistance. Its hydrolysis resistance, antioxidant, acid resistance and dry heat degradation resistance are better than nylon, but not alkali resistance. Based on this characteristic, polyester was modified by alkali decrement method.
3: Χαρακτηριστικά πολυεστερικού νήματος
Compared with polyester staple fiber, polyester filament has the following characteristics:
(1) Filament production is a single ingot production mode. There are dozens of monofilaments in a silk strip. From spinning to deformation, it needs to go through dozens of friction points, which is easy to produce wool. In addition, the filament is produced by multiple spindle positions and multiple machines. Due to factors such as equipment, process and operation, the filament produced by different spindle positions will have certain differences in performance, and even the inner and outer layers of a bobbin will be different. (2) The filament can imitate the differentiated fiber by physical deformation. If the shape of spinneret hole or twist is changed, silk fiber can be spun; By means of false twisting, air deformation, fiber mixing and compounding, the filament can have the style of wool; Hemp slub yarn can be made by the mixed fiber deformation of drawn yarn and pre oriented yarn; When the filaments with different melting points or different orientations are mixed and deformed, the filaments can obtain the appearance of hemp; Through various blowing and twisting technologies, network wire, network deformed wire, air deformed wire and cored wire can be made. Through strong twisting method, ring wire and wrinkled wire can be made; By means of composite spinning and mechanical stripping, ultra-fine filaments can be spun.
(3) The filament can imitate the differentiated fiber by chemical modification. For example, through copolymerization, blending, grafting and other methods, the fiber has special properties such as easy dyeing, heat preservation, heat resistance, flame retardant, anti fouling, anti pilling, anti-static, high moisture absorption and high water absorption. 3, Multi purpose polyester filament was mainly used in silk clothing in the early stage. With the development of various processing technologies, it has been extended to the whole clothing field such as wool imitation, linen imitation and cotton imitation, and developed to the fields of decoration, industry and non fiber. Clothing from underwear, shirts, jackets, suits to coats, ski shirts, etc; Decoration includes headdress, scarf, curtain, tapestry, carpet, sofa cover, car cushion cover, poncho, tablecloth, umbrella, etc; Bedding consists of bed sheet, quilt cover, pillow towel, quilt cover, bedspread, mosquito net, quilt, etc; Industrial sewing thread, cord thread, conveyor belt, filter cloth, rope, etc; Non fiber products include imitation leather products, films, bottles, etc.
