TW202413751A - Polyester elastic monofilament and preparation method thereof - Google Patents

Abstract

Disclosed herein is a method of preparing polyester elastic monofilament, comprising: melting and extruding thermoplastic polyester elastomer (TPEE), setting by heat followed by relaxing, and obtaining the polyester elastic monofilament.

Description

Polyester elastic monofilament and its manufacturing method

The present invention relates to a method for preparing polyester elastic monofilament and thermoplastic polyester elastic monofilament prepared by the method.

PET is made by polymerizing terephthalic acid monomers and ethylene glycol monomers. Due to its good heat resistance and chemical stability, as well as high mechanical strength, PET fibers are widely used in textile materials such as clothing, home furnishings, and industrial purposes. However, the disadvantages of PET are high modulus, high hardness, and its elastic recovery rate is far inferior to nylon 66. In order to improve this disadvantage of poor elastic recovery rate, it has been proposed to use 1,4-butanediol (1,4-BDO) monomers, 1,3-propylene glycol (1,3-BDO) monomers and terephthalic acid monomers to polymerize to produce PBT and PTT. Although the elasticity of fibers produced by PBT and PTT is better than that of fibers produced by PET, the elastic recovery rate of fibers is still insufficient. Although the elastic recovery rate of spandex elastic yarns currently on the market is very good, it cannot be recycled together with polyester, so it has a considerable impact on the environment. Patent TW I628323 discloses a method for manufacturing thermoplastic polyester elastic multifilaments and thermoplastic polyester elastic multifilaments produced by the method, but the patent only mentions multifilaments and does not mention single filaments.

In order to solve the problems existing in the above-mentioned prior art and achieve the purpose of the invention, the purpose of the present disclosure is to provide a polyester elastic monofilament with excellent stretch elasticity and elastic recovery rate, and a method for manufacturing polyester elastic monofilament with low production cost, high production efficiency and recyclable with polyester. The polyester elastic monofilament produced according to the method of the present invention has excellent elastic recovery force and can recover quickly when the external force is released. The yarn and fabric made by using this polyester elastic monofilament also have good stretch elasticity and elastic recovery rate.

One aspect of the present invention is to provide a method for manufacturing polyester elastic monofilaments, which includes the following steps: heating and melting a thermoplastic polyester elastomer (also known as TPEE) raw material, extruding it, and performing heat setting and relaxation treatment to obtain polyester elastic monofilaments.

In one embodiment, the thermoplastic polyester elastomer has an ultimate viscosity of about 1 to about 3.

In one embodiment, the temperature of the heating and melting step is between about 160 and about 300°C, preferably between about 200 and about 260°C.

In the manufacturing method of the present invention, the molecular structure of the thermoplastic polyester elastomer (TPEE) is composed of a hard segment and a soft segment, wherein the hard segment is an aromatic polyester, such as polyethylene terephthalate (hereinafter also referred to as PET) or polybutylene terephthalate (hereinafter also referred to as PBT), and the soft segment is a polyether ester, such as polytetramethylene ether glycol (hereinafter also referred to as PTMEG), wherein the weight ratio of the hard segment to the soft segment ranges from about 80:20 to about 20:80, and the number average molecular weight of the polyether glycol ranges from about 500 to about 5000.

In one embodiment, the hard segment of the thermoplastic polyester elastomer is polybutylene terephthalate (PBT).

In one embodiment, the soft segment of the thermoplastic polyester elastomer is polytetramethylene ether glycol (PTMEG).

In a specific embodiment, the method of the present invention further comprises: after extrusion, cooling, solidification and stretching steps.

In a specific embodiment, the method for manufacturing polyester elastic monofilament of the present invention comprises the following steps: heating and melting the thermoplastic polyester elastomer (TPEE) raw material at about 160-300°C through a screw extruder, quantitatively extruding it through a spinning nozzle at a spinning temperature of about 160-300°C, cooling and curing it with cooling air and oiling it, spinning and stretching it at an initial spinning speed of about 100-3500 m/min, a stretching temperature of about 20-180°C, a stretching ratio of about 1-10 times, and a setting temperature of about 20-210°C, and then winding it at a winding speed of about 100-5000 m/min after relaxation treatment to obtain polyester elastic monofilament with stretch elasticity.

Another aspect of the present invention is to provide a polyester elastic monofilament, which is manufactured according to the method described herein.

In a specific embodiment, the polyester elastic monofilament disclosed herein can be in the form of continuous long fibers or short fibers.

In a specific embodiment, the polyester elastic monofilament described in the present disclosure has a circular cross-section or a non-circular cross-section.

Another aspect of the present invention is to provide a yarn comprising the polyester elastic monofilament, a long fiber product or a short fiber product thereof, or a fabric made of the yarn.

Another aspect of the present invention is to provide a composite yarn, which is composed of the polyester elastic monofilament described herein. In a specific embodiment, the composite yarn is composed of the polyester elastic monofilament and other fibers.

Another aspect of the present invention is to provide a fabric, which is composed of the polyester elastic monofilament or composite yarn described herein.

Another aspect of the present invention is to use the polyester elastic monofilament prepared above to manufacture related fabrics using the general technical methods in the textile field.

The technical features of the present disclosure, including specific features, are disclosed in the claims. For a better understanding of the technical features of the present disclosure, the present disclosure is described in detail below with reference to the specification, the embodiments based on the principles of the present disclosure, and the drawings. In addition, the contents disclosed in the specification can be understood and implemented by those skilled in the art, and all equivalent changes or modifications that do not deviate from the concept of the invention can be covered by the claims.

All technical and scientific terms described in the specification and claims, unless otherwise defined, are definitions that are known to those with ordinary knowledge in the technical field to which the present disclosure belongs. The singular terms "one", "an", "the", or similar terms, unless otherwise specified, may refer to more than one object. "Or", "and", and "and" used in this specification, unless otherwise specified, all refer to "or/and". In addition, the terms "include" and "include" are open conjunctions without restrictions. The above definitions only illustrate the references of the term definitions and should not be interpreted as limitations on the subject matter. Unless otherwise specified, the materials used in the present disclosure are all commercially available and easily available.

Any numerical values such as concentrations or concentration ranges described herein are to be understood as being modified in all instances by the term "about". "About" means within an acceptable error range for the particular value, as determined by one of ordinary skill in the art, which will depend in part on how the value is measured or determined, i.e., the limitations of the measurement system. Unless otherwise expressly stated in the examples or elsewhere in the specification in the context of a particular assay, result, or embodiment, "about" means within one standard deviation, or up to 5%, whichever is greater, according to practice in the art.

Polyester is a general term for polymers produced by the polymerization of polyols and polyacids. It usually refers to polyethylene terephthalate (PET), but also includes other linear thermoplastic polymers such as polybutylene terephthalate (PBT). Polyester is a type of engineering plastic with excellent performance and wide application, which can be made into polyester fiber. Polyester elastomer (TPEE) is usually polymerized from terephthalic acid and 1,4-butanediol and is a thermoplastic elastomer.

According to the present disclosure, the polyester production method can be interfacial polymerization; melt condensation; liquid phase condensation; or transesterification polymerization, such as using acid catalysis to transesterify terephthalic acid with 1,4-butanediol to produce polyethylene terephthalate (poly(1,4-butylene terephthalate)). In addition, the addition of a catalyst is beneficial to the reaction, which can be selected from antimony compounds, tin compounds, titanium compounds, combinations thereof, or other metal catalysts or combinations thereof in the prior art. The amount of catalyst to achieve an acceptable polymerization rate may vary depending on the polymerization temperature and can be confirmed by experiment. The level of the catalyst can be 1 to 5,000 ppm, or more.

Thermoplastic polyester elastomer (TPEE), also known as copolyether ester, is a type of elastomer material. These materials have thermoplastic processing properties, and are elastic and resilient, and are not prone to elastic fatigue. The above properties come from the copolymer molecules composed of amorphous polyether segments (also known as hard segments, which can be aromatic polyesters, such as polyethylene terephthalate (PET) or polybutylene terephthalate (PBT)) and crystalline polyester segments (also known as soft segments, which can be polyether esters, such as polytetramethylene ether glycol (PTMEG)). Because the polyether segments and polyester segments copolymerize with each other, a macromolecular block skeleton is formed. After melt cooling, the hard segments (such as PBT) automatically cluster to form hard crystalline domains, connecting the soft elastic soft segments. The hard and soft segments together form mechanical interlocking and strong intermolecular attraction, but do not form a chemically interconnected network. Therefore, polyether elastomers can be heated above the melting point of the crystalline domain (about 200 ° C) and then processed.

According to the present disclosure, the hardness and melting point of thermoplastic polyester elastomer (TPEE) can be adjusted by the ratio of its hard segment to soft segment. Preferably, the weight ratio of the hard segment to the soft segment of the TPEE produced by the method of the present disclosure is in the range of about 80:20 to about 20:80; preferably, the weight ratio range is about 70:30 to about 30:70; preferably, the weight ratio range is about 60:40 to about 40:60; more preferably, the weight ratio range is about 55:45 to about 45:55; particularly preferably, the weight ratio range is about 50:50.

The properties of thermoplastic polyester elastomers (TPEE) can be defined by the intrinsic viscosity (IV). The intrinsic viscosity is one of the most commonly used parameters for characterizing polymers. The intrinsic viscosity represents the most relevant variable describing the viscosity of a polymer and is most closely related to the molecular weight.

The ultimate viscosity is a measure of the inherent resistance of a polymer to flow. In the present disclosure, the ultimate viscosity can be measured by methods of general technology in the art, for example, it can be measured according to the specifications of ASTM D2857, and is usually expressed as dL/g units. For example, the ultimate viscosity of a polyester (such as PBT) can be measured in a glass capillary viscometer with o-chlorophenol as a solvent at 35°C to measure the viscosity of a polymer concentration of 1 g/dL. Alternatively, a thermoplastic polyester elastomer is dissolved in a solvent of phenol/tetrachloroethane (50/50 wt) to prepare a 0.5 wt % solution, and its viscosity is measured using an Ubbelohde viscometer at 35°C.

According to the present disclosure, the limiting viscosity is measured according to the specification of ASTM D2857.

One embodiment of the present invention provides a method for manufacturing polyester elastic monofilaments, which includes the following steps: heating and melting thermoplastic polyester elastomer (TPEE) and then extruding it, performing heat setting and relaxation treatment to obtain polyester elastic monofilaments. The polyester elastic monofilaments produced by the method disclosed herein have excellent stretch elasticity and elastic recovery rate, which are better than PET fibers on the market.

In a specific embodiment, the method described herein includes: heating and melting a thermoplastic polyester elastomer through a screw extruder and then extruding it from a spinning nozzle.

In a specific embodiment, the method described herein includes: cooling and curing the thermoplastic polyester elastomer after extrusion. According to the present disclosure, the cooling method is not particularly limited; preferably, the thermoplastic polyester elastomer is cured by cooling air flow after extrusion. Therefore, in one embodiment, the cooling and curing is performed by air flow cooling. In one embodiment, the cooling and curing is followed by a stretching step.

Therefore, another embodiment of the present invention provides a method for manufacturing polyester elastic monofilaments, which includes the following steps: heating and melting a thermoplastic polyester elastomer through a screw extruder and then extruding it from a spinning nozzle, then cooling and solidifying it through cooling air, and then stretching, heat setting, and relaxing it to obtain polyester elastic monofilaments.

Another embodiment of the present invention provides a method for manufacturing polyester elastic monofilaments, which comprises the following steps: heating a thermoplastic polyester elastomer (TPEE) raw material to melt at 160-300°C through a screw extruder, quantitatively extruding the raw material through a spinning nozzle at a spinning temperature of 160-300°C, cooling and curing the raw material with cooling air and applying oil, spinning and stretching the raw material at an initial spinning speed of 100-3500 m/min, a stretching temperature of 20-180°C, a stretching ratio of 1-10 times, and a setting temperature of 20-210°C, and then winding the raw material at a winding speed of 100-5000 m/min after relaxation treatment to obtain a polyester elastic monofilament with elasticity.

In a preferred embodiment, the thermoplastic polyester elastomer (TPEE) is a thermoplastic polyester elastomer whose hard segment is polybutylene terephthalate (PBT). In a preferred embodiment, the thermoplastic polyester elastomer (TPEE) is a thermoplastic polyester elastomer whose hard segment is polybutylene terephthalate and whose soft segment is polyether ester; preferably, the polyether ester is polytetramethylene ether glycol (PTMEG).

According to the present disclosure, thermoplastic polyester elastomer (TPEE) is prepared according to the following process: TPA + 1,4-BDO + PTMEG → PBT type TPEE The meanings of the abbreviations are as follows: TPA: terephthalic acid; BDO: butanediol; PTMEG: polytetramethylene ether glycol; PBT: polybutylene terephthalate; TPEE: thermoplastic polyester elastomer.

In a specific embodiment, the thermoplastic polyester elastomer used in the present disclosure has an ultimate viscosity of about 1 to about 3, for example, IV = 1.0, 1.5, 2.0, 2.5, or 3.0; for example, its ultimate viscosity may be between 1.5 and 2.5. Preferably, the thermoplastic polyester elastomer of the present disclosure has IV = 1.0, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, 2.0, 2.1, 2.2, 2.3, 2.4, or 2.5.

In one embodiment, in the manufacturing method of the present invention, the melting temperature of the heating and melting step is between about 160°C and about 300°C. In a preferred embodiment, the melting temperature is between about 180°C and about 280°C; preferably, between 200 and 260°C, or between 200 and 250°C, or between 230 and 260°C, or between 230 and 250°C, or between 200 and 230°C. In a more preferred embodiment, the melting temperature is 160°C, 170°C, 180°C, 190°C, 200°C, 210°C, 220°C, 230°C, 240°C, 250°C, 260°C, 270°C, 280°C, 290°C, or 300°C.

The melting temperature of the heating and melting step can be adjusted according to the thermoplastic polyester elastomer used. The heating and melting should be carried out at a temperature of about 10°C to about 20°C above the melting point of the polymer. The higher the melting temperature that can be used, the better the spinning effect, but it should not be too high to avoid degradation. A temperature of about 10°C to about 20°C above the melting point of the polymer is optimal for achieving a good spinning balance without degrading the polymer. If the spinning temperature is too low, the polymer may solidify in the spinning nozzle and cause fiber breakage.

According to the present disclosure, the step of extruding after melting is preferably performed using a melt extruder. In a specific embodiment, the melt extruder capable of heating the elastomer and forming a melt is selected from the group consisting of a single screw extruder, a co-rotating or counter-rotating twin screw extruder, and a multi-screw extruder. The appropriate selection of the extruder screw and its geometry corresponding to the expected processing function (e.g., feeding, conveying, homogenizing, melting, and compression) are common knowledge in the art.

In one embodiment of the present disclosure, the stretching temperature is between about 20°C and about 180°C, for example, the stretching temperature is 20, 30, 40, 50, 60, 70, 80, 90, 100, 110, 120, 130, 140, 150, 160, 170, or 180°C.

In one embodiment of the present disclosure, the setting temperature is between about 20°C and about 210°C, for example, the setting temperature is 20, 30, 40, 50, 60, 70, 80, 90, 100, 110, 120, 130, 140, 150, 160, 170, 180, 190, 200, or 210°C.

In a preferred embodiment, the stretching temperature is lower than or equal to the setting temperature.

In a specific embodiment of the present disclosure, the stretching ratio is between about 1 and about 10 times, for example, 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 times.

According to the present disclosure, the aforementioned stretching ratio = the second roller speed (V2) / the first roller speed (V1), for example: stretching ratio 1.2 = V2/V1 = (1800 m/min) / (1500 m/min).

In one specific embodiment, the polyester elastic monofilament is prepared by a continuous method of continuously performing spinning extension, heat setting and relaxation. In another specific embodiment, the polyester elastic monofilament is prepared by a non-continuous method of first preparing a partial longitudinal yarn, and then stretching, heat setting and relaxing to prepare a polyester monofilament with stretch elasticity.

In one specific embodiment, the polyester elastic monofilament described in the present disclosure can be in the form of continuous long fibers or short fibers. In another specific embodiment, the polyester elastic monofilament described in the present disclosure has a circular cross-section or a non-circular cross-section.

According to the present disclosure, in the process of manufacturing the polyester elastic monofilament of this article, other functional additives can be added according to needs, including but not limited to antioxidants, flame retardants, heat storage and heat preservation agents, heat resistant agents, anti-ultraviolet agents, antistatic agents, fluorescent brighteners, antibacterial agents, matting agents, or color master batches, etc.

According to the present disclosure, the polyester elastic monofilament described herein can be used to manufacture long fiber products or short fiber products with good elongation and elastic recovery according to actual needs. The fibers of the polyester elastic monofilament can be fibers of various deniers. The term "denier (De)" herein is defined as the mass (grams) of 9000 meters of fiber. Denier describes the linear density of fiber, filament or yarn, the mass per unit length, and is measured according to ASTM D1577 Option B. In the present disclosure, the fiber denier of the polyester elastic monofilament is less than about 100, preferably less than 75, less than 50, less than 25, or less than 10.

The physical properties of the polyester elastic monofilament produced according to the method disclosed herein can be defined by measuring various parameters of the polyester elastic monofilament, the yarn and the fabric produced therefrom, as described below.

(1)   Infinite viscosity (IV):

The limiting viscosity is measured according to ASTM D2857.

(2) Yarn breaking strength and breaking elongation:

The test was performed using a STATIMAT ME automatic tensile tester (Textechno Inc, Germany) according to ASTM D 885.

(3) Boiling water shrinkage rate:

Roll the sample 10 times on the length measuring instrument, attach a load of 2g/D to the sample, and measure the length at this time as L0. Then put the loaded sample into 98°C boiling water for 15 minutes, take out the sample and dry it, and measure the length after treatment as L. Calculate the boiling water shrinkage rate according to the following formula.

Boiling water shrinkage (%) = [(L ₀ -L)/L0] × 100%

(4)   Elastic recovery rate of yarn under constant load:

Take a sample of 50cm long yarn, fix one end of the sample to the upper fixing clip, hang a 0.01g/De preload on the other end, and mark at 50cm intervals, and record the length at this time as L0. Then hang a load of 3.6g/De, and after 72 hours, measure the length between the marks, and record the length at this time as L1. Then remove the load, hang a 0.01g/De preload again after 1 hour, and measure the length between the marks, and record the length at this time as L2. Repeat the above measurement 3 times. Use the following formula to calculate the yarn elastic recovery rate. The test result is expressed as the average value of 3 times after leaving it for 1 hour after removing the load.

Yarn elastic recovery rate (%) = [(L1-L2)/(L1-L0)] × 100%

(5)   Elastic recovery rate of constant elongation yarn:

Take a 50cm long yarn sample, first fix one end of the sample to the upper fixed clamp, hang a 0.01g/De preload on the other end, and mark at 50 cm intervals, and clamp it with a chuck, so that the distance between the sample fixing clamps is 50 cm (length is L0), then stretch 40, 80, 120% (length is L1) at a stretching speed of 50cm/min, let the sample stand for 1min, then return to the original position at the same speed, and then stand for 3min. After repeating the above method for 5 times, open the chuck and hang the preload again, measure its length (length is L2), and calculate the yarn elastic recovery rate with the following formula. The test results are expressed as the average rate of 3 times.

Yarn elastic recovery rate (%) = [(L1-L2)/(L1-L0)] × 100%

In addition to the contents described in the embodiments, the method disclosed herein can be implemented with reference to the general technology in the art. Patent TW I628323 is incorporated into the present disclosure by reference in its entirety.

Embodiment 1

A screw extruder was used to heat and melt PBT-TYPE TPEE with IV=1.5 at a melting temperature of 200~250°C, and then discharged by a metering pump, entering a spinning box with a spinning temperature of 230°C, and extruded from a spinning nozzle assembly. After being cooled and solidified by cooling air and oiled by a tanker, it was wound at an as-spun speed of 1500 m/min, an elongation ratio of 1.2, an elongation temperature of 50°C, a setting temperature of 125°C, a relaxation rate of 10%, and a winding speed of 1620 m/min to obtain 50De/1F polyester elastic monofilament. The breaking strength, breaking elongation, boiling water shrinkage, elastic recovery of yarn under constant load, and elastic recovery of yarn under constant elongation of the polyester elastic monofilament of this embodiment were measured according to the above-mentioned measuring method. The results are shown in Table 1.

Embodiment 2

A screw extruder was used to heat and melt PBT-TYPE TPEE with IV=1.5 at a melting temperature of 200~250°C, and then discharged by a metering pump, entering a spinning box with a spinning temperature of 230°C, and extruded from a spinning nozzle assembly. After being cooled and solidified by cooling air and oiled by a tanker, it was wound at an as-spun speed of 1500m/min, an elongation ratio of 1.2, an elongation temperature of 50°C, a setting temperature of 125°C, a relaxation rate of 10%, and a winding speed of 1620 m/min to obtain 150De/1F polyester elastic monofilament.

Embodiment 3

A screw extruder was used to heat and melt a PBT-type thermoplastic polyester elastomer (PBT-TYPE TPEE) with IV=1.5 at a melting temperature of 200~250°C, and then discharged through a metering pump, entering a spinning box with a spinning temperature of 230°C, and extruded from a spinning nozzle assembly. After being cooled and solidified by cooling air and oiled by a tanker, it was wound at an as-spun speed of 1500m/min, an elongation ratio of 1.2, an elongation temperature of 50°C, a setting temperature of 125°C, a relaxation rate of 10%, and a winding speed of 1620 m/min to obtain 20De/1F polyester elastic monofilament.

Embodiment 4

Using a screw extruder, PBT-TYPE TPEE with IV=1.5 is heated to a melting temperature of 200~250°C, then discharged by a metering pump, enters a spinning box with a spinning temperature of 238°C, and is extruded from a spinning nozzle assembly. After being cooled and solidified by cooling air and oiled by the oil tanker, the spinning speed (as-spun speed) is 1500m/min, the elongation ratio is 1.0, the relaxation rate is 5%, and the winding speed is 1425 The 60De/1F polyester elastic monofilament was wound at a speed of 500 m/min to obtain a 50De/1F polyester stretched elastic monofilament. The elastic monofilament was then wound at a stretching ratio of 1.2, a stretching temperature of 60°C, a shaping temperature of 110°C, and a winding speed of 500 m/min to obtain a 50De/1F polyester stretched elastic monofilament.

Embodiment 5

Using a screw extruder, PBT-TYPE TPEE with IV=1.5 is heated to a melting temperature of 200~250°C, then discharged by a metering pump, enters a spinning box with a spinning temperature of 238°C, and is extruded from a spinning nozzle assembly. After being cooled and solidified by cooling air and oiled by the oil tanker, the spinning speed (as-spun speed) is 1500m/min, the elongation ratio is 1.0, the relaxation rate is 5%, and the winding speed is 1425. m/min to obtain 100De/1F polyester elastic monofilament, and the elastic monofilament is taken and then subjected to a pseudo-twisting process with an elongation ratio of 2.0, a hot plate temperature of 150°C and a winding speed of 400 m/min to obtain 50De/1F polyester pseudo-twisted elastic monofilament.

Embodiment 6

A screw extruder was used to heat and melt PBT-TYPE TPEE with IV=2.5 at a melting temperature of 230~260°C, and then discharged by a metering pump, entering a spinning box with a spinning temperature of 250°C, and extruded from a spinning nozzle assembly. After being cooled and solidified by cooling air and oiled by a tanker, it was wound at an as-spun speed of 1500m/min, an elongation ratio of 1.2, an elongation temperature of 50°C, a setting temperature of 125°C, a relaxation rate of 10%, and a winding speed of 1620 m/min to obtain 100De/1F polyester elastic monofilament.

Embodiment 7

A screw extruder was used to heat and melt PBT-TYPE TPEE with IV=2.5 at a melting temperature of 230~260°C, and then discharged by a metering pump, entering a spinning box with a spinning temperature of 250°C, and extruded from a spinning nozzle assembly. After being cooled and solidified by cooling air and oiled by a tanker, it was wound at an as-spun speed of 1500m/min, a stretching ratio of 1.0, a stretching temperature of 25°C, a setting temperature of 125°C, a relaxation rate of 10%, and a winding speed of 1620 m/min to obtain 100De/1F polyester elastic monofilament.

Comparison Example 1

Using a screw extruder, PET with IV=0.64 was heated and melted at a melting temperature of 280-290°C through a screw extruder, and then discharged through a metering pump, entering a spinning box with a spinning temperature of 290°C, extruded from a spinning nozzle assembly, and after being cooled and solidified by cooling air and oiled by a tanker, it was wound at an as-spun speed of 700m/min, a stretching temperature of 90°C, a setting temperature of 180°C, a stretching ratio of 3.5, a relaxation ratio of 10%, and a winding speed of 2520m/min to obtain 50De/1F PET stretched monofilament. The breaking strength, breaking elongation, boiling water shrinkage, elastic recovery of yarn under constant load, and elastic recovery of yarn under constant elongation of the polyester elastic stretched filament were measured according to the above-mentioned measuring method. The results are shown in Table 1.

Comparison Example 2

The commercially available 40 ^d /3 ^f spandex was used to measure the breaking strength, breaking elongation, boiling water shrinkage, elastic recovery of the yarn under a constant load and elastic recovery of the yarn under a constant elongation of the polyester elastic stretched filament according to the above-mentioned measurement method. The results are shown in Table 1.

Table 1 Embodiment 1 Comparison Example 1 Comparison Example 2 raw material TPEE PET Spandex Yarn properties Total fiber density (De) 50 50 40 Fiber number (F) 1 1 3 Breaking strength (g/d) 1.7 3.9 1.3 Elongation at break (E%) 251 50 500 Boiling water shrinkage (%) 4.2 4.0 1 Elastic recovery rate of yarn under constant load (%) @1 hour after removing the load 93.9 13.5 95.8 Elastic recovery rate of constant elongation yarn (%) @Stretch 40% 97.2 ＜10 98.0 @Stretch 80% 95.2 --- 96.3 @Stretch 120% 93.6 --- 94.5

In the contents disclosed in the embodiments of this specification, it is obvious to those with ordinary knowledge in the field to which this disclosure belongs that the aforementioned embodiments are only illustrative and not limiting; those with ordinary knowledge in the technical field to which this disclosure belongs can implement it through many changes and substitutions, and it does not differ from the technical features of this disclosure. According to the embodiments of the specification, this disclosure can be implemented in many ways without hindering implementation. The claims provided in this specification define the scope of this disclosure, which covers the aforementioned methods and structures and inventions equivalent thereto.

without

Claims (14)

A method for manufacturing polyester elastic monofilaments, comprising: Melting thermoplastic polyester elastomer (TPEE) and extruding it, performing heat setting and relaxation treatment to obtain polyester elastic monofilaments. The method of claim 1, wherein the limiting viscosity of the thermoplastic polyester elastomer is between 1 and 3. The method of claim 1, wherein the temperature of the melting step is between 160 and 300 °C. A method as claimed in claim 3, wherein the temperature of the melting step is between 200 and 260 °C. In the method of claim 1, the hard segment of the thermoplastic polyester elastomer is polybutylene terephthalate (PBT). As in the method of claim 1, the soft segment of the thermoplastic polyester elastomer is polytetramethylene ether glycol (PTMEG). The method of claim 1, wherein the ratio of the hard segment to the soft segment of the thermoplastic polyester elastomer is between 80:20 and 20:80. The method of claim 1 further comprises: after extrusion, performing cooling and solidification and stretching steps. In the method of claim 1, the polyester elastic monofilament is a long fiber or a short fiber. A method for manufacturing polyester elastic monofilaments, comprising: After heating and melting the thermoplastic polyester elastomer (TPEE) raw material at 160-300°C through a screw extruder, quantitatively extruding it through a spinning nozzle at a spinning temperature of 160-300°C, cooling and curing it with cooling air and oiling it, spinning and stretching it at an initial spinning speed of 100-3500 m/min, a stretching temperature of 20-180°C, a stretching ratio of 1-10 times, and a shaping temperature of 20-210°C, and then winding it at a winding speed of 100-5000 m/min after relaxation treatment to obtain polyester elastic monofilaments. A polyester elastic monofilament is produced by the method according to any one of claims 1 to 10. A composite yarn is composed of the polyester elastic monofilament of claim 11. The composite yarn of claim 12 is composed of a composite of the polyester elastic monofilament and other fibers. A fabric is composed of the polyester elastic monofilament of claim 11 or the composite yarn of claim 12 or 13.