The core difference between polyester DTY yarn and traditional polyester filament

In the field of polyester fiber materials, polyester, as one of the most widely used synthetic fibers, plays an important role in many fields such as textiles, clothing, and industrial fabrics with its excellent physical and chemical properties. Although polyester DTY yarn (drawn textured yarn) and traditional polyester filament belong to the same polyester fiber family, there are significant core differences in production process, product structure, performance characteristics, and application fields. These differences determine their unique positioning and application value under different market demands.
1. Differences in production process
There is a fundamental difference between the production process of polyester DTY yarn and traditional polyester filament. Traditional polyester filament is usually produced by one-step or two-step method. The one-step method is melt direct spinning, which directly spins polyester melt into filament through the spinning assembly. The process is relatively simple and has high production efficiency; the two-step method is to first melt the polyester chips and spin them into pre-oriented yarn (POY), and then make the finished filament through processes such as stretching and heat setting. The filaments produced by this production method have high orientation and crystallinity, and the fiber morphology is relatively regular.
The production of polyester DTY yarn adds a deformation processing link on the basis of traditional filament production. Generally, pre-oriented yarn (POY) is used as raw material, and the fiber is deformed into a spiral curling shape under the action of heat and mechanical force through false twisting deformation process. During the false twisting deformation process, the fiber is first heated and softened, and then the twist is formed under the action of the false twister. When the fiber leaves the hot zone and cools, the twist is fixed to form a DTY yarn with a permanent curling shape. This process gives DTY yarn a unique curling structure, which makes it show different performance characteristics from traditional filaments in subsequent applications.
2. Product structure differences
The difference in production process directly leads to the difference in product structure between polyester DTY yarn and traditional polyester filament. Due to the relatively sufficient orientation and crystallization process in the production process of traditional polyester filament, the fiber macromolecular chain is arranged regularly and is in a straight and parallel state. The fiber surface is smooth and the structure is compact. The crystallinity is generally between 40%-60%. This structure gives traditional filaments high strength and rigidity, but also limits their softness and fluffiness.
After false twisting, the polyester DTY yarn forms a spiral or wavy curled structure, which leaves a large number of gaps between the fibers. From the microscopic structure, the macromolecular chains of the DTY yarn show an irregular arrangement at the curling point, which reduces the overall crystallinity of the fiber, usually around 20%-40%. The curled structure and low crystallinity not only give the DTY yarn a unique appearance, but also give it good fluffiness and softness, which is in sharp contrast to the smooth and tight structure of traditional filaments.
3. Differences in performance characteristics
(I) Mechanical properties
In terms of mechanical properties, traditional polyester filaments have higher breaking strength and initial modulus due to their higher orientation and crystallinity. Generally, the breaking strength can reach 4-6 cN/dtex, and the initial modulus is between 100-200 cN/dtex. This makes traditional filaments less likely to deform when subjected to external forces, and is suitable for fields with high strength requirements, such as tire cords, ropes, etc. However, higher strength and modulus also make it feel harder and less flexible.
The curled structure of polyester DTY yarn allows the curled part to stretch when subjected to force, thus having better extensibility and elastic recovery. Its breaking strength is relatively low, generally 3-5 cN/dtex, but its elongation at break is high, up to 150%-300%, and its elastic recovery rate is also significantly better than traditional filaments. This unique mechanical property enables DTY yarn to quickly return to its original shape after stretching, making it more comfortable to wear and less prone to wrinkles.
(II) Wearability
In terms of wearability, traditional polyester filaments have a smooth surface and a tight structure, and the fabric has poor moisture absorption. It is easy to feel stuffy when worn, and it is easy to generate static electricity and pilling, which affects the wearing comfort and aesthetics.
The curled structure of polyester DTY yarn increases the gaps between fibers, improving the fluffiness and air permeability of the fabric. At the same time, its low crystallinity and irregular molecular arrangement structure enhance the fiber surface's ability to absorb moisture, improving the fabric's hygroscopicity. In addition, the curled structure of DTY yarn can also reduce the friction between fibers, reduce the tendency to pilling, make the fabric more comfortable and beautiful to wear, and more suitable for making underwear and fashionable clothing.
(III) Appearance performance
The surface of traditional polyester filament fabric is smooth and flat, with a strong luster, showing a tough texture. This appearance feature has unique advantages in some specific application fields, such as outdoor clothing, decorative fabrics, etc.
Due to the curled structure of the fiber, the surface of polyester DTY silk fabric presents a soft luster and natural texture, and it feels soft and plump. It has an appearance and feel similar to natural fiber fabrics, which greatly improves the quality and grade of the fabric and has broad application prospects in the fields of mid-to-high-end clothing fabrics and home textiles.
4. Differences in application fields
Based on the differences in the above performance characteristics, polyester DTY yarn and traditional polyester filament also have different application fields. Traditional polyester filament, with its high strength and high modulus, is mainly used in the field of industrial textiles, such as tire cord, geotextile, rope, safety belt, etc., which have high requirements for the strength, wear resistance and dimensional stability of materials. In the field of clothing, traditional filament is often used to make outdoor functional clothing, using its non-deformation and tear resistance to meet the needs of outdoor activities.
Polyester DTY yarn is mainly used in the field of clothing fabrics and home textiles due to its good softness, fluffiness, elasticity and comfortable wearing performance. In terms of clothing, it is widely used to make underwear, shirts, casual wear, sportswear, etc., which can provide consumers with a comfortable wearing experience; in the field of home textiles, it is often used to make curtains, sofa fabrics, bedding, etc., and its soft luster and natural texture can enhance the texture and beauty of home decoration. In addition, with the continuous development of textile technology, polyester DTY yarn has gradually been used in some functional textile fields, such as high-performance fabrics with moisture absorption and perspiration, antibacterial and deodorizing functions.