CN-121992515-A - Polyamide 12 stretch textured yarn with high rebound and excellent dimensional stability and preparation method thereof

CN121992515ACN 121992515 ACN121992515 ACN 121992515ACN-121992515-A

Abstract

The invention discloses a polyamide 12 stretch textured yarn with high rebound and excellent dimensional stability and a preparation method thereof, wherein polyamide 12 slices with relative viscosity of 2.0-3.5 are dried until the water content is lower than 700ppm, then melt-spun at 210-245 ℃ and wound at a spinning speed of 1000-4500 m/min to prepare a pre-oriented yarn, then the pre-oriented yarn after hot stretching is subjected to false twist texturing, the draft ratio is 1.20-1.80, the D/Y ratio is 1.5-2.4, the deformation hot box temperature is 100-170 ℃, and the microwave-assisted shaping hot box temperature is 120-160 ℃, so that the polyamide 12 stretch textured yarn is obtained. The scheme solves the problems of narrow processing window and poor stability of the polyamide 12 in high-speed false twist deformation by optimizing the pre-oriented yarn structure of the polyamide 12 and precisely controlling the texturing and heat setting process, and the prepared polyamide 12 stretch textured yarn not only maintains the low water absorption and light weight characteristics of the original polyamide 12, but also has high elasticity and excellent dimensional stability, and is suitable for the fields of high-end sports apparel, swimwear, medical textiles and the like.

Inventors

ZHANG XUYANG
XIE ZHIRONG
DAI JUNMING
ZHANG ZHOU
DONG QIAO
XIE WENHAO
CHEN WENXING

Assignees

苏州翌锦科技有限公司
现代纺织技术创新中心(鉴湖实验室)
浙江理工大学

Dates

Publication Date: 20260508
Application Date: 20260316

Claims (8)

1. The preparation method of the polyamide 12 stretch textured yarn with high rebound and excellent dimensional stability is characterized by comprising the following steps: Step S1, slicing polyamide 12 with the relative viscosity of 2.0-3.5, and drying for 10-20 hours under the protection of vacuum or dry nitrogen at 80-105 ℃ to ensure that the water content is lower than 700ppm; Step S2, conveying the polyamide 12 slices subjected to the drying treatment in the step S1 into a screw extruder, carrying out melt extrusion at 180-245 ℃, metering the melt by a metering pump, extruding the melt by a spinneret plate to form tows, uniformly cooling and solidifying the tows under the conditions of 50-200 Pa of wind pressure, 3-22 ℃ of wind temperature and 70+/-5% of relative humidity of circular blowing or side blowing, oiling and bundling the tows, and winding the tows at a spinning speed of 1000-4500 m/min to obtain the polyamide 12 pre-oriented yarns with breaking strength not less than 3.0cN/dtex and breaking elongation of 80-150%; S3, placing the polyamide 12 pre-oriented yarn in the step S2 on a creel, leading out a yarn bundle to enter a first feeding roller, controlling the feeding tension to be 0.05-0.15 cN/dtex, and enabling the yarn bundle treated by the first feeding roller to enter a first hot box for drafting, wherein the temperature of the first hot box is 100-170 ℃, and the stretching multiple is 1.3-2.5 times; the heated and drawn yarn bundles enter a cooling plate for forced cooling, the temperature of the cooling plate is 20-60 ℃, the deformation state of the yarn bundles is fixed, the cooled yarn bundles enter a false twister for false twisting, the false twisting number is 2500-3500 twists/m, the D/Y ratio is 1.5-2.4, the yarn bundles obtain an elastic curled structure, the yarn bundles after false twisting enter a second feeding roller, the linear speed of the second feeding roller is lower than that of the first feeding roller, the linear speed of the second feeding roller is 200-800 m/min, a first overfeeding area is formed, the overfeeding rate is 5-12%, the yarn bundles enter a microwave auxiliary shaping hot box for relaxation hot shaping, the yarn bundles after relaxation hot shaping enter a third feeding roller, the speed of the third feeding roller is controlled to be lower than that of the second feeding roller, the overfeeding rate is 3-8%, the yarn bundles pass through an oiling roller or an oiling nozzle for oiling for 0.5-2%, the yarn bundles pass through a yarn guide roller for winding, and the yarn bundles are wound into a yarn bundle with a tension of 200-12 cm/m, and the yarn bundles are wound into a yarn bundle is stretched and wound into a yarn bundle with a tension of 200-0.05/cm.
2. The method for preparing the polyamide 12 drawn textured yarn with high rebound and excellent dimensional stability according to claim 1, wherein the screw extruder is a single screw extruder, four heating areas are arranged on the single screw extruder along the material conveying direction, the temperatures of the four heating areas are increased stepwise, specifically, the temperature of one area is set to be 180-200 ℃, the temperature of the other area is set to be 190-220 ℃, the temperature of the other area is set to be 200-240 ℃, and the temperature of the other area is set to be 210-245 ℃.
3. The method for preparing the polyamide 12 drawn textured yarn with high rebound and excellent dimensional stability according to claim 1, wherein the spinning component comprises a filtering sand layer and a spinneret plate, wherein the filtering sand degree in the filtering sand layer is 60-100 meshes, the number of spinneret holes of the spinneret plate is 10-144 holes, the aperture is 0.15-0.25 mm, and the arrangement mode of the spinneret holes is diamond or concentric circle distribution.
4. The method for producing a drawn textured yarn of polyamide 12 having both high rebound and excellent dimensional stability as claimed in claim 1, wherein the surface linear velocity ratio between the first feeding roller and the second feeding roller is set to 1.20 to 1.80:1, which is the draft ratio in the process.
5. The method for producing a drawn textured yarn of polyamide 12 having both high rebound and excellent dimensional stability as claimed in claim 1, wherein the temperature of the texturing heat box is set to 100 to 170 ℃ to bring the yarn bundle to a plastic state.
6. The method for producing a polyamide 12 drawn textured yarn having both high rebound and excellent dimensional stability as claimed in claim 1, characterized in that the temperature of the microwave-assisted setting hot box is set to 120-160 ℃ to eliminate internal stress and fix the crimp structure.
7. The method for preparing the polyamide 12 drawn textured yarn with high rebound and excellent dimensional stability according to claim 1, wherein the false twister is a friction false twister, a rotor false twister or an air texturing machine, and when the false twister adopts the friction false twister, the structure of the false twister is a stacked disc type or a leather ring type, and the friction disc is made of ceramic, polyurethane or silicon carbide coating materials, and the corresponding assembling mode is '1-4-1' or '1-5-1'.
8. A polyamide 12 stretch textured yarn with high rebound and excellent dimensional stability is characterized in that the polyamide 12 stretch textured yarn is prepared by the preparation method of any one of claims 1 to 7, the breaking strength of the polyamide 12 stretch textured yarn is more than or equal to 4.0cN/dtex, the elongation at break is more than or equal to 45%, and the elastic recovery is more than or equal to 75%.

Description

Polyamide 12 stretch textured yarn with high rebound and excellent dimensional stability and preparation method thereof Technical Field The invention relates to a polyamide fiber stretch textured yarn and a preparation method thereof, in particular to a polyamide 12 stretch textured yarn with high rebound and excellent dimensional stability and a preparation method thereof, belonging to the technical field of chemical fiber manufacturing. Background Polyamide fibres, commonly referred to as nylon, are a class of synthetic fibres containing recurring amide groups (-CONH-) in their main chain. Representative varieties thereof include polyamide 6 (PA 6, formed by ring-opening polymerization of caprolactam) and polyamide 66 (PA 66, formed by polycondensation of hexamethylenediamine and adipic acid), and also special nylons such as polyamide 46, polyamide 12 and semiaromatic polyamides. Polyamide fibers generally have outstanding breaking strength, excellent abrasion resistance and good rebound resilience due to strong hydrogen bonding by amide groups in the molecular chain and a regular molecular arrangement. Thus, the most representative polyamide 6 and polyamide 66 are widely used for producing stretch textured yarns (Draw Textured Yarn, DTY) and imparting bulk, elasticity and coverage to the fibers by false twist texturing, and are widely used in the fields of sportswear, socks, undergarments, decorative fabrics, and the like. However, conventional polyamide DTY fibers have several performance stubs in application. Firstly, the strong hydrophilicity of the amide groups results in higher moisture absorption rate of the fibers (the moisture regain of PA6 and PA66 is about 4.0-4.5%), swelling easily occurs after moisture absorption, secondly, moisture enters an amorphous region to weaken intermolecular hydrogen bonding action, so that the wet state modulus is remarkably reduced, the fabric is easily softened and deformed in a wet state, furthermore, the glass transition temperature of the polyamide is lower (about 50-60 ℃), molecular chains are easily rearranged in the wet heat treatment or dynamic stress process, the dimensional stability is greatly influenced by environment, and the shrinkage rate is easily increased after washing or creep occurs after long-term use. These limitations have limited their further application in high-end sportswear, professional swimwear, outdoor equipment, and industrial textiles with high dimensional accuracy requirements (e.g., airbags, conveyor base fabrics, etc.). In order to break through the performance bottleneck of the conventional polyamide materials, researchers have recently come to pay attention to the application potential of long carbon chain polyamides in the textured yarn field. Polyamide 12 (PA 12) is a typical representation of long carbon chain polyamides, and the density of amide groups in the molecular main chain is significantly lower than that of PA6 and PA66, and this structural feature gives the material its unique combination of low density, excellent hydrolysis resistance, good flexibility of the molecular chain, and excellent dimensional stability under both dry and wet conditions. Based on the above-mentioned inherent advantages, polyamide 12 is considered as one of ideal raw materials for preparing DTY having both low hygroscopicity and high dimensional stability, and is particularly suitable for application scenes with high requirements on humidity sensitivity and dimensional accuracy. However, although PA12 has significant potential in material properties, it still faces serious process challenges during Draw Textured Yarn (DTY) processing. The viscoelastic behavior of the melt also exhibits a significant difference compared to PA6 and PA66, where PA12 has a lower glass transition temperature (Tg) and melting point (Tm). When the high-speed false twist texturing technology is adopted on conventional terylene or PA6 texturing equipment, three technical problems are needed to be overcome, namely 1) the initial crystallization structure and the stretchability of the PA12 pre-oriented yarn (POY) are difficult to be matched with the stretching heat setting conditions in the high-speed texturing process, 2) the technological window of the texturing process is extremely narrow, the problems of yarn breakage, yarn stiff, fluctuation of rolling performance and the like are extremely easy to occur in the production process, and 3) the elastic recovery rate and the rolling stability of the textured yarn are difficult to reach ideal levels even if the textured yarn is molded, so that the practical application effect of the textured yarn in high-elasticity fabrics is restricted. Therefore, it is necessary to provide a polyamide 12 stretch textured yarn with high rebound and excellent dimensional stability and a preparation method thereof, so as to meet the requirement of special fields such as high-end sports apparel, swimwear and medical textile on the envir