DTY (Draw Texturing Yarn) is the finished filament after POY (Pre-Oriented Yarn) is stretched continuously or simultaneously on a texturing machine, and deformed by a twister.
DTY - Drawn Textured Yarn
Texturing is not only a nice-to-have feature. Texturing is typically essential to allow the yarn to be treated further. For instance, synthetic fibers like nylon yarn fall under this category. They are frequently exceedingly smooth, rigid, and nearly glass-like, which would hamper their assignment in the textile chain even though they have some advantages over natural yarns, such as regularity, resistance to mildew, or ease of care. Different texturizing techniques are used to create texture on drawn textured yarn. The process of adding crimps, coils, or loops to a continuous filament yarn is known as texturizing. A partially oriented yarn is utilized as the feed yarn during the yarn texturizing process, and after several treatments, various textures are drawn on the yarn.
On drawn textured yarn, the texture is produced using a variety of texturizing methods. Texturizing is the process of incorporating coils, crimps, or loops into a continuous filament yarn. During the yarn texturizing process, a partially oriented yarn is used as the feed yarn, and after several treatments, the yarn is covered in a variety of textures.
Types of Drawn Textured Yarn
This type of drawn textured yarn is a form of textured yarn that offers enhanced extensibility and recovery. They are made utilizing a single heating zone for edge crimping or fake twist texturizing. Their area of use is where extensibility and recovery from the stretch are required. This type of drawn textured yarn has a high stretch of 300–400% and a medium–high bulk.
Modified Stretch Yarns
This type of drawn textured yarn is like a middle ground between stretch and bulky yarn in terms of texture. They are created when a second heating zone is present during the process of crimping an edge or a false twist. They are utilized in situations where less extensibility and greater aesthetics are desired. They have considerable mass and a moderate stretch (100-150%).
These are made using the air jet, stuffer box, fear crimping, and knit-de-knit processes. They have a large bulk and modest stretch.
The Different Processes of Texturizing for Drawn Textured Yarn
1. False Twist
2. Edge Crimping
3. Stuffer box process
4. Gear Crimping
6. Air Textured
False Twist Texturizing Method
In this technique to manufacture drawn textured yarn the multi-filament yarn moves through a false twist texturizing machine in the following order: feed roller, heating roller, cooling roller, second heater, oil roller, twister, and take-up roller. With 300% stretch, modified stretch yarn can be produced. A POY yarn is permitted to flow between two shafts during this operation. The POY yarn is next inserted into shaft 1, where it is then transmitted onto shaft 2. The yarn needs to be drawn and twisted after being fed into the machine. Once the yarn exits shaft 1, it is heated by a heater so that it can be thermoset at a low temperature. The yarn is then quickly brought to a cooling system, which keeps the yarn at a low temperature to thermoset the twist. The twisting is accomplished by a friction mechanism, such as a group of revolving discs; there are several types, such as belts. Various requirements must be met to obtain a modified stretch yarn. The temperature should be lower than the primary heater and should first go via a secondary heater with an overfeed.
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.
Edge Crimping Texturing Method
The edge crimping texturing of this process results in stretch yarn. This procedure is taking a dull knife edge and drawing the filament across it. The filament or the knife edge could both be heated. The portion of the filament closest to the knife travels a shorter distance than the filament at the outside borders when we draw it over the knife edge. This causes the outer filament to stretch more than the filament next to the edge. The phenomena of bilateral compression and extension strain, which results in crimps, is what causes this. The resulting yarn has a twist-free helical structure.
Stuffer Box Method
In this procedure, a heating chamber known as a stuffer box is used to cram the filaments into a small area. The filaments are removed from the stuffer box after being heat-set in their crimped form. After that yarn tensioner provides proper yarn tension. These yarns are less extensible, soft, thick, and have good absorption qualities. Although the crimp's amplitude and frequency can be adjusted, not all of them will have the same size. The stretch range is the same as that of the modified stretch yarn, or between 100 and 150%.
A heated yarn is sent between two cold rotating gears in the process. Due to the varying pitch of the gear teeth, mechanical distortion occurs when they are compressed. Their primary industries of application are hosiery and upholstery. This is typically used in conjunction with other texturizing techniques and is not the primary texturizing procedure.
Drawn fiber can be knit-de-knit texturized to create the crimp of a knitted-loop shape. This method involves knitting yarn into a tubular fabric, setting it in place with heat, and then unraveling it to create textured yarn. Most hosiery is made using this yarn.
A single type of yarn or a combination of filament yarns can be used for air-jet texturing. In the latter scenario, fancy yarn blends are produced. In this texturing technique, a dry yarn or a yarn combined with a small bit of water is fed into a high-speed jet of air. But since there are so many very fine filaments in yarns with this texture, tangling is more likely. These yarns are known as Air Textured Yarns (ATY) because an air jet is used to produce the texturizing on the yarn. It is a mechanical process. A cold air stream is utilized to create bulked yarns with limited extensibility during the air-jet texturizing process.
This process of texturing can produce permanent distortions, crimps, loops, coils, or crinkles on the yarns without destroying the essential continuity of the filaments. This method not only improves the texture of the yarns but also gives yarns a soft and woolly feel. This process of texturing increases the warmth and comfort of the fabrics which are made using these types of yarns. This is mainly because the loops or crimps can entrap a multitude of small pockets of air which prevent the air movement through fibers and hence holds the fabric together.
The Benefits of Drawn Textured Yarns
Because air is trapped within the yarn's interstices, one of the most significant benefits of textured yarn is that it provides excellent comfort. Additionally, it offers greater dimensional resistance, improved crease resistance, and superior pill resistance. They look better and are fuller. It has greater form retention abilities and is simple to wash and dry. Yarns can be textured to increase their volume, allowing the yarns to trap air and give garments made with the yarn better thermal insulating characteristics. Additionally, synthetic yarns may be textured to resemble traditionally spun natural fibers by becoming hairier and softer. A yarn's stretchiness can even be changed by texturing.
Uses of Drawn Textured Yarn
Hosiery, knitted outerwear, shape-retaining knit fabrics for men's and women's suits and overcoats, and other textile products are all made with textured yarns. They are also used to create synthetic fur, carpets, blankets, and fabric for draperies and upholstery.
Additionally, Drawn Textured Yarn (DTY) has a unique method that generates a variety of purposes for DTY yarn that are appropriate for varied end-users. DTY yarn is therefore frequently used in knitting and weaving. Most manufacturers also utilize DTY yarn for fabrics and final products including clothing, furniture, seat covers, outer/inner garments, bags, etc. Drawn textured yarn is used in fashion garments and luxury wear. Drawn textured yarn is also used in fancy laces, quilted covers & skin-clinging garments.
Properties of Drawn Textured Yarn
Drawn textured yarn (DTY) can also come in a variety of colors, including semi-dull, raw white, dope-dyed black, and dope-dyed hues.
Drawn textured yarn has good insulation properties, so it is helpful for insulated and warm clothing.
Lightweight with good covering properties and good extensibility.
Due to drawn textured yarn it gives a woolly and mat appearance.
Drawn textured yarn has high wear and tear resistance.
DTY yarn has a very low moisture content.
Quality metrics for Drawn Textured Yarn
Strength and Elongation
For the strength of fibers, the higher the better, for drawn textured yarn (DTY), the strength of 2.5cN/dtex and the elongation of 12% to 30% can meet the requirements of weaving and wearing. The higher its toughness (strength x elongation/2), the better. Fibers with high toughness not only have good internal quality, but are also wear-resistant and fold-resistant. In actual production, different weaving methods have different requirements for tenacity. For example, weft knitting machines require DTY yarn to have a much lower strength than warp knitting and weaving. The elongation range of DTY yarn for weft yarns is wider, but the elongation of warp yarns cannot too high. In DTY yarn production, the strength and elongation are generally controlled by adjusting the draw ratio of the filament. As the draw ratio increases, the strength of the filament increases and the elongation decreases. However, when the stretching ratio is too large, the strength and elongation of the filaments will decrease.
The crimp properties include crimp rate KE, crimp stability KB and boiling water shrinkage. High shrinkage rate, DTY yarn has a plump feel, beautiful appearance and good elasticity. Crimp stability indicates the degree of gradual loss of crimp during weaving and wearing, and is inversely proportional to crimp. Therefore, these two indicators must be taken into account in actual production. DTY yarn with a higher shrinkage rate can cover up part of the uneven dyeing, so the shrinkage rate is often controlled to be slightly higher during the production process. However, if DTY yarn is dyed with a bobbin in post-processing, the bobbin shrinkage of DTY yarn with a high shrinkage rate is large, making it difficult to unwind the bobbin after dyeing. If DTY filaments are used for dyeing or dyeing after weaving into fabrics, there is no limit, and the shrinkage rate can be controlled to be higher at this time.
For DTY yarn with high physical properties such as strength, elongation, crimping rate, evenness unevenness and fiber structure unevenness, there will be disadvantages such as horizontal stripes and color difference after weaving into fabrics. Therefore, it must be controlled during the DTY yarn production process and detected in time after the finished product inspection, so as to avoid the DTY yarn with poor dyeing uniformity from being mixed into the normal products, resulting in a large amount of degradation of the final fabric.
One of the main quality problems of drawn textured yarn at present is the broken filament, which will affect the smooth progress of the post-weaving process and the quality of the fabric. Different weaving processes have different requirements for broken filament. The drawn textured yarn for weaving needs to be woven after twisting, sizing or networking, so the requirements for fluffing are not strict. The drawn textured yarn used by the water jet loom does not want broken filament. In the knitting process, the weft knitting yarn has a short weaving process and low speed, so the requirements for broken filament are not strict; while the production speed of the warp knitting yarn is high, each DTY yarn must pass through the needle eye, and the broken filament is easy to cause end breakage , should be strictly controlled.
Ossified Filament and Tight Spot Filament
Ossified filament refers to the segmented, continuous and non-fluffy tightly twisted filaments that appear on DTY yarn. Tight spot filament refers to the unserious ossified filament, that is, the continuous length of the ossified filament is very short, almost point-like. Ossified filament and tight spot filament can be judged by visual inspection and appearance classification. The ossified filament can also be identified on dyed stockings. It is darker than the normal filament and has a strip shape. Tight spot filament has dark spots on the sock shaft, which is generally difficult to distinguish.
Principle of False Twist Deformation
If one end of the filament is fixed, hold the other end to make it rotate by itself. Every time it rotates, a twist is added to the filament. Turn counterclockwise to get S twist, and turn clockwise to get Z twist. If both ends of the filament are fixed, and the middle part is held and rotated, with the holding point as the boundary, the upper and lower parts will respectively have the same number of twists and opposite twists.
If the filament passes through the fixed points at both ends in a moving manner and rotates the holding point, the twist will change. Along the moving direction of the filament, before the holding point, the filament is twisted (assuming Z twist) ; After passing the holding point, add S twists equal to the number of Z twists. Since the upper and lower twist directions of the holding point are opposite, in fact all the Z twists added before the holding point are untied. This process of twisting first and then untwisting is called false twisting.
On the false twist texturing machine, the small rotor is a rotating holder, and the feeding roller and the intermediate roller not only fix the two ends of the filament, but also continuously transport the filament forward. The filament is twisted before entering the small rotor, untwisted after exiting the small rotor, and finally the filament is untwisted.
Heating and Cooling
Heating and cooling are necessary to exploit the thermoplastic properties of synthetic fibers to obtain false twist effects. Heating is carried out in the twisting stage of the false twisting process, the purpose of which is to use the thermal movement of molecules to eliminate the internal stress caused by twisting and to fix the twisting deformation. In addition, the plasticity of the filament increases after heating, and the rigidity is weakened, which can reduce the twisting tension and facilitate twisting.
The purpose of cooling is to fix the plastic deformation obtained by twisting deformation. If the filament in its thermoplastic state passes immediately through the rotating holder (small rotor), untwisting will not work, resulting in a stiff filament with very poor bulk. When cooled to below the secondary transition temperature (glass transition temperature, 81°C), the deformation after twisting has been solidified. Although untwisted, each single filament still retains its original curled shape, which appears fluffy and elastic.
To sum up, the false twist deformation is to use the thermoplasticity of the filament, heat and shape after twisting, then cool, and untwist all the added twist after cooling. Due to heating and cooling after twisting, the curved shape of the filament is fixed, and the filament still maintains the curved shape after untwisting.
Notes on DTY Yarn Production
The so-called good product is to meet the specified needs and potential features. In simple terms, it is able to bring a good sense of experience to users. For example, in our texturing industry, texturing workers are users of raw material POY, and are very sensitive to the quality of raw materials. Bad tails, fluff, uneven tension, broken wires for no reason, etc. If the user experience is not satisfactory, it is generally because the quality of the raw materials is not good.
Then, most people don’t know how our own product DTY yarn will give downstream users the experience, so the texturing process lacks a little awareness of product quality. From the process point of view, if you can understand the use characteristics of the next process, it is the key to do a good job in the quality of this process.
Understand the Customer's Process Characteristics
When working in a nylon DTY yarn processing factory, even though I have worked in workshop management and production positions for many years, sometimes I still don’t know what kind of DTY filament the customer needs. We only know that according to our consistent experience, we can make conventional standard DTY filaments, and take "not stiff or fluffy, and all indicators are balanced and sufficient" as the process standard, and it is good for customers to buy it back without any problems. Even if a customer complains, it is only a partial solution to a certain problem, and there is no systematic overall quality management. In fact, to be precise, in order to subdivide customer complaints, at the very least, we need to understand which link has the problem and what is the root cause of the problem? However, these post-event remedies have caused losses to customers after all. Therefore, quality management must focus on "goals", refine each link, and have a complete understanding of the requirements and characteristics of each process. Taking blanket enterprise customers as an example, there are processes such as weaving, pre-finishing, brushing, ironing, shaping, printing and dyeing, post-finishing, and finished product packaging. The following briefly describes the processes that are directly related to DTY yarn and the quality management key control points in .
The first is the weaving process. Good weaving can increase the weaving output and ensure that the loom can produce the proper number of meters of cloth in one shift. When DTY yarn adjusts the process, it is necessary to know which loom will be used to weave these batches of DTY yarn. The characteristics of warp knitting and weft knitting are different, and the process must be targeted. According to experience, if the product satisfies the weaving process, it can meet 60%/70% of the needs. The first requirement of weaving is that it should be easy to do and not easy to break. This requires DTY yarn to have good strength, good bundling, good shaping, and good unwinding.
The use of warp knitting upper creel also requires small residual torque and no excessive looping. When using warp knitting upper warping machine, it is especially required that the fixed length of DTY yarn is consistent, while weft knitting also requires the standard tail of DTY yarn, which not only reduces Reduce the labor intensity of weaving workers, promote work efficiency without wasting raw materials.
Secondly, there should be no horizontal bars for circular knitting machines, and no vertical bars for warp knitting machines. This requirement is reflected in the texturing machine to check the differences between each spindle position to ensure the quality consistency of each DTY yarn.
Thirdly, the weight of the cloth is up to the standard, and there are precise requirements for the fineness of the facing filament under the condition of a certain bottom thread. If weaving is still a preliminary judgment on the condition of the cloth surface, then the pre-trimming, brushing, and ironing processes are another exact test of the smoothness of the cloth surface and the consistency of the stripes.
Fourth, the control of network fastness. For the passability of DTY weaving, network cohesion will be used. Appropriate network air pressure can make the filaments more bundled and passable, and there is no need to worry about the bulkiness of the blanket. Because there is a brushing program after the cloth surface is cut, it can brush the bundled chemical fiber monofilaments well, so that the wool surface is fine and uniform, but if the network pressure of DTY yarn is too high, it will affect the brushing effect, resulting in partial brushing failure. opening phenomenon.
Therefore, the brushing process will in turn affect the adjustment of the air pressure of the DTY yarn network. Problems such as uneven evenness and uneven tension of DTY yarn will be fully exposed after scalding. After weaving, the slight unevenness of the cloth surface will be compensated to a certain extent after ironing, but if it cannot be eliminated by ironing, it will basically be finalized. The effect of scalding is also related to the setting temperature of DTY yarn. The setting temperature of DTY yarn is generally 20° lower than the scalding temperature, otherwise the scalding effect will be poor.
Finally, the control of the finalizing temperature. Shaping is to control the stability of the fabric size, and there are requirements for the two shrinkage rates of the DTY yarn process. In the printing and dyeing process, the consistency of DTY's inherent quality has been re-inspected. Due to the characteristics of Dayouguang products, there is not much difference in appearance, such as slight cold jump, uneven heating of the hot box, uneven false twist tension, uneven oiling, etc., but it will still be reflected in printing and dyeing.
Understand Customers and End Customers
Quality standards are relative terms, and the ultimate goal is to satisfy end customers. The DTY yarn produced by the weaving enterprises is still not the final customer. It depends on what the produced cloth is used for. The customer requirements of weaving enterprises are also different, especially the regional differences of export products are relatively large. Even if the products produced according to the national standard are not in line with the actual local requirements and preferences, they are not good products. Therefore, you should actively ask the customer what style of product his customer needs, so that he can adjust the DTY yarn process that suits the style in a targeted manner.
Quality Can Sometimes Be Low
Communicate well with the customer, and after understanding his customer's needs, he can make some more economical adjustments. Due to regional habits, aesthetic concepts, life pursuit requirements and specific uses, etc., the final customer audience sometimes does not need your product quality to be too high. More economical and practical.
Salud Style - Drawn Textured Yarn Manufacturer
Salud Style uses the most recent, equally capable high-speed draw texturizers to produce DTY yarn. Our quality control team checks the quality of the DTY yarn at every stage to minimize the defect rate and maximize quality assurance. Regarding dyeability, there are also comprehensive quality checks. Electronic package-size measuring devices guarantee uniform packaging of the texturized yarn.
The new generation of DTY yarn manufactured by Salud Style refers to differentiated fibers with high quality, high function, low consumption and low emission. It not only refers to the performance and state characteristics of textured yarn DTY, but also emphasizes the renewable raw material source of DTY yarn and the low energy of the manufacturing process. consumption, low emission, flexibility and intelligence.
At present, well-known chemical fiber enterprises in developed countries not only have traditional advantages such as technology, equipment and brand in high-end DTY yarn manufacturing and new product research and development, but also attach great importance to the improvement of intelligent manufacturing level, and actively promote the intelligent manufacturing of chemical fiber industry in accordance with the intelligent manufacturing strategy of their respective countries. Manufacturing upgrades reflect the advantages of "data-driven" in terms of key technologies. Salud Style's DTY yarn production will also develop in the direction of equipment intelligence, production flexibility, and management intensification.