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Special Draw-Texturing for Polyester Folded DTY

Polyester folded yarn is an important branch of fancy yarn. Polyester folded yarn is spun into irregular thick places and details in the length direction of ordinary single yarn or multi-threads, and has the appearance of uneven distribution of thickness. Polyester folded yarn can give the fabric a unique three-dimensional fancy effect. The production technology of Polyester folded yarn is that an additional device added to the ordinary spinning frame to change the speed or stop of the front roller, thereby changing the normal draft multiple, and suddenly a thick spot is produced on the normal yarn, like a slub. In the same way, the middle and rear rollers can also be overfeeded suddenly, which will also change the draft multiple and produce bamboo knots. This creates different slub silk effects.The parameters of Polyester folded yarn include base yarn density, slub thickness, slub length and slub spacing. Due to the special structure of slub yarn, the cloth style is closely related to the above four parameters, and their various combinations determine its special style on the cloth. By utilizing the different lengths, thicknesses, pitches and raw materials of the slub parts of Polyester folded yarn, a variety of varieties with different styles can be developed to meet the needs of various consumers.


The drawing is adjusted from the speed of the first roller to the second roller, and is generally determined by the remaining draw ratio of POY, which directly affects the fineness, strength and elongation of the yarn. As the draw ratio increases, the strength of the yarn increases, the elongation decreases, the crimp rate decreases, and the crimp stability improves. This is mainly because with the increase of the draw ratio and the special transformation principle, the fiber macromolecules stretch and are neatly arranged along the fiber axis. The orientation of the drawn filament increases, and the crystallization of the macromolecules is induced at the same time, thereby increasing the strength of the filament. Because under high draw ratio, the orientation degree of macromolecules in the fiber increases, the possibility of further stretching decreases, so during the drawing process, the ability to be stretched again decreases; in addition, as the draw ratio increases, the tension High limits the rapid displacement required for the development of fiber curl, and the fiber curl is dense, so the curl rate is reduced and the curl stability is improved. If the draw ratio is too low, the tension will be small, easy to fluctuate, slip, and produce tight twists. Therefore, appropriately increasing the draw ratio within a certain range can make the twisting stable.After extrusion of the fiber, its chainlike molecules are in an amorphous or disordered arrangement. The filament fiber must be drawn to develop the desirable strength, pliability, toughness, and elasticity properties. Some fibers are cold-drawn; others must be hot-drawn. Drawing aligns the molecules in a more parallel arrangement and brings them closer together so they are more crystalline and oriented. The amount of draw (draw ratio) varies with intended use, determines the decrease in fiber size and controls the increase in strength.


To Increase Strength

To increase orientation & crystallinity

To decrease elongation at break (EB)


Texturing is a treatment in which flat filaments are distorted to have loops, coils, curl or crimps along their length to gain increased bulkiness, porosity, softness and elasticity in some situations.

Methods Of Texturing

Textured yarns can be produced by following methods


Air-texturing is mainly realized through the air deformation nozzle. The original filaments enters the nozzle and is blown open and disrupted by the air flow, and then is accelerated in the accelerating wire feed tube. Before leaving the nozzle, each single filament remains generally parallel, but when leaving the nozzle, the filaments generate permanent distortions, crimps, loops, coils, or crinkles on the yarns without destroying the essential continuity of the filaments.. A certain length of free yarn segment appears due to overfeeding. While the yarns are intertwined, a network occurs above the bending point, forming the basic structure of air-textured yarn.


It is one of the most popular method to produce high stretch yarn. In false-twist coiling, the yarn bundle is twisted, heated, and untwisted in one continuous operation. A heat-set coil within each filament results; the yarn itself has no twist (hence the name “false-twist).
False twist deformation processing is a special process that subjects thermoplastic filaments to mechanical stress at high temperatures to change the apparent tissue structure of the fiber and thereby change the fiber properties. The principle is that the fiber produces twisting stress due to twisting. This stress is eliminated by heat setting treatment, so that the twisted and crimped shape is fixed. Although it was untwisted afterwards, the fiber could no longer return to its original parallel state and became a deformed yarn with a certain crimpability.
False twists come in two different varieties. S- and Z-twist. There are both minor and significant differences. Both S and Z stand for genuine yarn twists. One yarn has been twisted in the opposite direction from the other yarn, which makes a difference. In essence, one yarn is the exact opposite of the other. The difference is particularly noticeable since S-twisted yarn will appear differently in a piece of fabric than Z-twisted yarn.


To gain increased bulkiness, porosity, softness and elasticity in some situations

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