As we all know, the pursuit of “softness” in products such as quilts and knitted underwear is always a major theme. In order to achieve “softness”, one of the requirements for yarns is to use as small a twist as possible. However, ordinary yarns are too small The twist will cause difficulty in spinning and increase the number of ends broken in weaving. Therefore, in the past, achieving “softness” could only balance spinning and weaving. Select a compromise value for the yarn twist requirements. The advent of untwisted yarn provides another brand-new solution to achieve “softness” for industries such as quilts and knitting. The outstanding features of untwisted yarn products are their super “softness” and water absorption
What is twistless yarn?
Twistless processing: A spinning method that uses an adhesive to bond the fibers in the fiber strips to each other into yarn.
After the roving is drawn by the drafting device, the sliver is sent to the twisting drum, and the thin layer of adhesive from the tank on the return drum is contacted. The fiber sliver is Several small rotating pressure rollers are transported forward together with the drum. One of the small pressure rollers also makes axial reciprocating motion at the same time, twisting the fiber strips into a circular cross-section, so that each fiber can evenly contact the bonding agent. .The round fiber strips are dried by the heater, and the fibers stick to each other to form yarn. The spinning speed can be 2 to 4 times greater than conventional spinning methods, and the yarn produced can be used for weaving. An adhesive is used to bond the fibers in the yarn sliver to each other to form a yarn. There is no twist in the yarn sliver, and the strength is obtained by the mutual adhesion between the fibers. It is a new spinning method.
Uses of twistless yarn
Home textile products (pajamas, bed blankets, quilts, towels, bath towels, shower caps, high-end uniforms, baby suits, pillowcases, etc.) are soft, bulky, and sweat-absorbent, and are made of cotton, warm, light, transparent, and thin Features.
How is twistless yarn formed?
Yarling principle:
It is made of soluble PVA (polyvinyl alcohol) filament or mulberry silk wrapped in untwisted cotton Bundle the surface to form a wrapping yarn, which has good wear resistance and withstands a certain tension when weaving towels. Then after weaving into finished products, PVA or mulberry silk is dissolved in water to make the terry loops untwisted and fluffy. in the fabric.
Yarn forming method:
1. Adhesive method
Use adhesive to tightly bind fibers together through pseudo-adhesive effect. The adhesion mixing of fibers can be done directly or during drawing. The yarn formed after the fibers are adhered and mixed on the draw frame can be directly supplied to the twistless worsted spinning machine after drying. It eliminates the four processes of traditional spinning process, namely two drawing processes, roving process and spinning process. This twist-free yarn-forming method can increase yarn output 10 times compared to ring spinning. It overcomes the obstacles of high output in ring spinning and rotor spinning. Yarn can be spun directly from slivers, and some can even be spun directly from combs. The output of net-spun untwisted yarn can be as high as 300~400 meters per minute. In addition, the distance between the draft rollers can be adjusted to adapt to the spinning of fibers of different lengths, thereby realizing the spinning of cotton yarn and yarn on the same machine. Wool yarn and other different types of yarn.
2. Soft wrapping method
This method uses parallel spinning to spin the first yarn. The primary yarn is composed of soluble filament fibers and untwisted parallel short fibers. The soluble filament fibers are spirally wound around the untwisted parallel short fibers. The filaments are dissolved during the finishing process, leaving only the core without Twisted short yarn. In this process, the role of the filament is only to provide the tension required during the weaving process.
2.2.3 Reverse twisting method
Raw materials: water-soluble vinylon thread + cotton yarn. Process: doubling → reverse twisting.
Process points: The reverse twisting process is the most critical process for processing untwisted yarn
Reverse twisting of ply yarns The number should be equal to the twist of the spun cotton yarn and PVA yarn
Use an appropriate small spindle speed
The height of the balloon is required Suitable
Appropriately increase the indoor humidity, increase the cohesion of vinylon, and reduce breakages
Adjust the doubling tension and untwisting. Winding tension to solve the knotting phenomenon
Characteristics of untwisted yarn
① Since the yarns in the fabric formed by untwisted yarn are in a band-like or flat shape, the coverage coefficient of the fabric increases, the fabric looks thick and tight, has a good fluffy feel, and the weight of the fabric can be reduced accordingly .
② Since the untwisted yarn has no twist and shrinkage, the shrinkage rate of the fabric formed is smaller than that of traditional fabrics, which can save raw materials.
③ The fibers in untwisted yarn are exposed to the outside and can fully contact with the dye, so the dye is easy to dye, so the dyeing performance is better.
④ The fibers in the fabric made of untwisted yarn have a high degree of parallelism, so they have a better gloss than the fabric made of twisted yarn.
Disadvantages of untwisted yarn
Untwisted towels feel super soft It is thick, but during use, no matter how high-grade the twistless one is, there will be some lint loss, which is a shortcoming caused by the craftsmanship that is difficult to eliminate. But we can wash it with warm water before use, which can remove most of the floating hair and improve the hair loss phenomenon
Does untwisted yarn have twist?
Untwisted yarn is generally collectedThe soft wrapping method is used, which uses conventional spinning methods to spin the first yarn.
The soluble vinylon fiber is then wrapped around the surface of the virgin yarn to form a plied yarn. The customer melts the water-soluble vinylon fiber during the finishing process, leaving only the virgin yarn on the cloth surface. Make the cloth surface soft and achieve the desired effect;
In this process, the role of water-soluble vinylon fiber is only to provide the tension required in the weaving process to meet the customer’s needs Require.
What is the difference between untwisted yarn fabric and twisted yarn fabric?
1. Fiber arrangement
Untwisted yarn fabric Since the fibers in the yarns forming the fabric are arranged in parallel, the freedom of the fibers The fiber has a large degree of strength, so the fiber becomes a ribbon or flat shape after being extruded, which makes it have different characteristics from the fabric formed by traditional spinning methods.
2. Appearance
Because The reason why the yarns in the fabric have a belt-like cross-section increases the coverage coefficient of the fabric, so the fabric looks thick and tight, has a good fluffy feel, and the fabric quality is relatively light
3. Processing technology
Since the untwisted yarn has no twist shrinkage, the fabric shrinkage ratio is Traditional yarn fabrics are small, which can greatly save raw materials; untwisted yarn fabrics have good dyeing performance and can achieve a mercerized effect. The fibers in untwisted yarn are exposed and can fully contact the dye, so the dye is easy to be dyed. Twisted yarn often needs to be mercerized to make the fibers arranged more neatly to obtain good luster, while untwisted yarn does not need this One treatment; the fluffy effect of untwisted yarn fabrics can be used to weave lighter, thicker and more comfortable fabrics.
What is the difference between weakly twisted yarn and untwisted yarn?
In terms of durability:
Untwisted yarn: The durability of untwisted yarn is lower than that of weakly twisted yarn;
Weakly twisted yarn: The durability of weakly twisted yarn is higher than that of weakly twisted yarn, but lower than that of veil.
In terms of twist:
Untwisted yarn: no twist;
Weakly twisted yarn: Weakly twisted yarn does not complete the twist of the cotton yarn during spinning, and generally only completes about 70% of the twist of the cotton yarn.
In terms of advantages and disadvantages:
Untwisted yarn: The fabric of untwisted yarn feels super soft and thick, but there will be some lint loss during use. This is a shortcoming caused by the process that is difficult to eliminate. It can be washed with warm water before use to remove it. Floating wool can very well improve the shedding phenomenon;
Weakly twisted yarn: it will not become significantly hardened due to repeated exposure to water, and the most important thing is that it will not produce any lint during the production process. additional environmental pollution.
1. Untwisted yarn is made by making the center of the fiber hollow. Weakly twisted yarn is a deformed yarn made by a deformation process in which two yarns are twisted together, heat-set, and then wound separately.
2. Weak twist: Cotton fiber and water-soluble vinylon are spun into yarn respectively, plied and twisted into threads. After the dimension is reduced during fabric finishing, the towel fabric can reach a high Softness and high absorbency. Weak twist means there is less twist (rotation) on the 10CM yarn, and no twist means there is no twist. Twisting the yarn is a means to improve the fastness of the yarn, but it will reduce the comfort, water absorption and breathability of the yarn. In terms of comfort, untwisted towels are worse than weakly twisted towels, but their durability is not as good as weakly twisted towels. </p
