Modified thermoplastic elastomer multifilament and processing method thereof

Abstract

The invention discloses a modified thermoplastic elastomer multifilament and a processing method thereof, the produced elastomer multifilament has higher breaking strength of more than 4.0 cn / dtex, and meanwhile, the elasticized product has higher crimp shrinkage which can be kept above 40%, and can be directly used for weaving high-end fabrics to avoid the defect of using spandex.

Description

Technical Field

[0001] The invention relates to a field, and in particular to a modified thermoplastic elastomer multifilament and a processing method thereof. Background Art

[0002] At present, spandex as an elastomer fiber has been widely used. The amount of spandex added in various new fabrics and functional clothing is getting higher and higher, ranging from 3% to 30%. Spandex has a large elongation at break (can reach 10000) and a high elastic recovery rate. A small amount of addition can significantly improve the elasticity of the fabric, so it is likened to the "MSG" in textiles. However, as a thermosetting material, spandex has the following problems: First, it is not recyclable. Since spandex is generally a thermosetting fiber, it is difficult to recycle. With the expansion of the application range of spandex, a large number of spandex fabrics will inevitably be abandoned, causing huge pollution and waste. Secondly, it is difficult to dye. The indicators such as dyeing depth and color fastness of spandex are not ideal. After blending and dyeing with other fibers, "whitening" and color difference will appear. For some high-end fabrics and clothing with a high amount of spandex, the problem of whitening will seriously restrict the application of spandex. Especially when mixed with nylon to dye dark tones, the color difference is particularly obvious. In order to improve the dyeing effect of spandex, extreme dyeing conditions are often used, which may cause abnormal phenomena such as melting of spandex yarn, thereby affecting the elasticity and use of the fabric. Moreover, spandex is produced by solution spinning, which requires a large amount of solvents during the production process, causing environmental pollution. In addition, spandex has benzene ring groups in its molecular structure, which causes it to become more severely yellowed due to light aging.

[0003] Currently, the elastic fibers on the market include T400, T800, PTT, PBT, etc., but their breaking strength generally does not exceed 3.2cN / dtex, and the elastic recovery of dry heat curling shrinkage does not exceed 40%.

[0004] The breaking strength of the elastomer monofilament or multifilament currently on the market is 2.6-3.0 cN / dtex, and the stability of its dry heat shrinkage rate is difficult to control, and the subsequent weaving dimensional stability is difficult to control.

[0005] To solve the above problems, thermoplastic elastomer fibers using melt spinning technology have attracted widespread attention in the textile industry. Among them, polyester elastomers are considered to be thermoplastic elastic fiber materials with great application potential due to their excellent elasticity, recyclability, good dyeing performance, and low pollution in production process. Summary of the invention

[0006] To this end, it is necessary to provide a modified thermoplastic elastomer multifilament and a processing method thereof to solve the problems that the breaking strength of the elastomer monofilament or multifilament currently on the market is 2.6-3.0 cN / dtex, and the stability of its dry heat shrinkage rate is difficult to control, and the subsequent weaving dimensional stability is difficult to control.

[0007] To achieve the above object, the present invention provides a method for processing a modified thermoplastic elastomer multifilament, comprising the following steps:

[0008] S01: Dry TPEE to meet spinning standards;

[0009] S02: putting the dried TPEE into a screw extruder for melt extrusion;

[0010] S03: Use a conduit to introduce the antioxidant and the TPEE after melt extrusion into the spinning box respectively, and mix them in a certain proportion;

[0011] S04: spinning fibers from TPEE mixed with an antioxidant;

[0012] S05: Long side blowing cold cutting to cool the fiber;

[0013] S06: winding the cooled fiber onto the first hot roller for stretching, winding onto the second hot roller for shaping after the stretching is completed, winding onto the third hot roller for shaping after the stretching is completed, winding onto the fourth hot roller for shaping after the stretching is completed, and winding onto the fifth hot roller for shaping after the stretching is completed, thereby forming a TPEE fully stretched silk fiber;

[0014] Furthermore, after step S06, the following steps are also included:

[0015] S07: Wind the TPEE fully drawn silk fiber into silk cakes, and store them in warehouse for use after quality inspection.

[0016] Furthermore, after step S07, the following steps are also included:

[0017] S08: Place the TPEE fully drawn silk fiber cake into the texturizing device, and perform heating and drawing, false twisting, cooling and shaping, and winding in sequence.

[0018] Furthermore, in step S08:

[0019] The upper temperature box of the texturizing device is heated at 150-180°C, and the lower temperature box is heated at 70-110°C; and / or

[0020] The production speed is controlled at 400-600m / min; and / or

[0021] The stretching ratio is controlled between 1.01-1.3; and / or

[0022] The D / Y ratio is 1.4-2.

[0023] Furthermore, the drying temperature in step S01 is 80-110° C., and the drying time is 4-8 hours.

[0024] Furthermore, the input mass of the antioxidant in step S03 is 0.1%-1% of the total mass, and the input mass of the TPEE after melt extrusion is 99%-99.9% of the total mass.

[0025] Furthermore, in step S05:

[0026] The long corridor length for cold cutting is 12 meters; and / or

[0027] The temperature of the cold wind is 16-20℃; and / or

[0028] The side wind pressure is 580Pa.

[0029] Further, in step S06: the temperature of the first hot roller is 60-90°C, the winding speed is 500-700m / min, the temperature of the second hot roller is 100-140°C; the stretching ratio is 1.2-1.4, and the winding speed is 600-850m / min; the temperature of the third hot roller is 60-100°C; the stretching ratio is 2.8-3.2, and the winding speed is 1800-2500m / min; the temperature of the fourth hot roller is 60-100°C; the stretching ratio is 1.01-1.02, and the winding speed is 1900-2600m / min; the temperature of the fifth hot roller is 100-140°C; the stretching ratio is 0.95-0.98, and the winding speed is 1900-2500m / min.

[0030] The present invention also provides a modified thermoplastic elastomer multifilament, which is made by using the processing method of a modified thermoplastic elastomer multifilament described in any one of the above technical solutions.

[0031] Furthermore, the fineness of the TPEE fully drawn silk fiber after the treatment in step S06 is 70-600D, and the number of pores is 12-144F.

[0032] Different from the prior art, the elastomeric multifilament produced by the above technical solution has a higher breaking strength>4.0cn / dtex. At the same time, the elasticized product has a higher curl shrinkage rate that can be maintained above 40%, and can be directly used for weaving high-end fabrics to avoid the shortcomings of using spandex.

[0033] The invention adopts a stepwise stretching method, and then performs low-temperature relaxation and shaping, and finally performs two stretching shaping steps to stably control the dry heat shrinkage of the yarn within a range of 20±2%, thereby solving the problem of poor size control of spandex fabrics. DETAILED DESCRIPTION

[0034] In order to explain the technical content, structural features, achieved objectives and effects of the technical solution in detail, the following is a detailed description in conjunction with specific embodiments.

[0035] Reference to "embodiment" herein means that the specific features, structures or characteristics described in conjunction with the embodiment may be included in at least one embodiment of the present application. The term "embodiment" appearing in various places in the specification does not necessarily refer to the same embodiment, nor does it particularly limit its independence or association with other embodiments. In principle, in the present application, as long as there is no technical contradiction or conflict, the various technical features mentioned in the embodiments can be combined in any way to form a corresponding implementable technical solution.

[0036] Unless otherwise defined, the technical terms used in this document have the same meanings as those generally understood by those skilled in the art to which this application belongs; the use of relevant terms in this document is only for describing specific embodiments and is not intended to limit this application.

[0037] In the description of this application, the term "and / or" is an expression used to describe the logical relationship between objects, indicating that three relationships may exist, for example, A and / or B, which means: A exists, B exists, and A and B exist at the same time. In addition, the character " / " in this article generally indicates that the objects before and after are in an "or" logical relationship.

[0038] In the present application, terms such as “first” and “second” are merely used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship of quantity, priority or sequence between these entities or operations.

[0039] Without further limitations, in this application, the words "include", "comprises", "has" or other similar expressions used in the sentences are intended to cover non-exclusive inclusion. These expressions do not exclude the presence of additional elements in the process, method or product including the elements, so that the process, method or product including a series of elements may include not only those limited elements, but also other elements not explicitly listed, or also include elements inherent to such process, method or product.

[0040] Similar to the understanding in the Examination Guidelines, in this application, expressions such as "greater than", "less than", "exceed" and the like are understood to exclude the number itself; expressions such as "above", "below", "within" and the like are understood to include the number itself. In addition, in the description of the embodiments of this application, "multiple" means more than two (including two), and similar expressions related to "multiple" are also understood in this way, such as "multiple groups", "multiple times", etc., unless otherwise clearly and specifically limited.

[0041] In the description of the embodiments of the present application, space-related expressions used, such as "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "vertical", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicate the orientation or position relationship based on the orientation or position relationship shown in the specific embodiments, which is only for the convenience of describing the specific embodiments of the present application or facilitating the reader's understanding, and does not indicate or imply that the referred device or component must have a specific position, a specific orientation, or be constructed or operated in a specific orientation, and therefore cannot be understood as a limitation on the embodiments of the present application.

[0042] Unless otherwise expressly specified or limited, in the description of the embodiments of the present application, the terms such as "install", "connect", "connect", "fix", "set", etc. used should be understood in a broad sense. For example, the "connection" can be a fixed connection, a detachable connection, or an integrated setting; it can be a mechanical connection, an electrical connection, or a communication connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium; it can be the internal connection of two elements or the interaction relationship between two elements. For technicians in the technical field to which the present application belongs, the specific meanings of the above terms in the embodiments of the present application can be understood according to the specific circumstances.

[0043] It should be noted that the slice material used for processing and manufacturing the modified thermoplastic elastomer multifilament of the present invention is TPEE (thermoplastic polyester elastomer), and its D-type Rockwell hardness range should be 55D-75D. The material has the characteristics of high flexibility, aging resistance, low temperature resistance and the like.

[0044] The present invention provides a method for processing a modified thermoplastic elastomer multifilament, comprising the following steps:

[0045] S01: Dry TPEE to meet the spinning standard. The spinning standard can refer to the following parameters: moisture content is less than 0.02%. By drying the TPEE raw material, hydrolysis and material defects can be prevented. Specifically, if the moisture content of polymer materials such as polyester is too high during the spinning process, severe hydrolysis will occur, resulting in a decrease in molecular weight and an increase in the intrinsic viscosity of the melt, thereby affecting the spinnability and quality of the fiber. Furthermore, the drying temperature in step S01 is 80-110°C, and the drying time is 4-8 hours. The dried TPEE can meet the spinning standard.

[0046] S02: Put the dried TPEE into the screw extruder for melt extrusion. By melt extruding TPEE, the TPEE chain is fully expanded and flowed under the action of heat and mechanical shear force, thereby obtaining a uniform melt, which helps to remove moisture and volatile substances in the raw materials. These impurities may cause material degradation or bubble generation at high temperatures, affecting the continuity of spinning and the quality of the finished yarn, and improving the fluidity and uniformity of TPEE.

[0047] S03: Use a conduit to introduce the antioxidant and the TPEE after melt extrusion into the spinning manifold respectively, and mix them in a certain proportion. By mixing the antioxidant, the thermal oxidation degradation of TPEE during the processing can be prevented, and the material can be protected from the attack of free radicals, thereby maintaining the physical properties of TPEE. Specifically, the input mass of the antioxidant in step S03 is 0.1%-1% of the total mass, and the input mass of the TPEE after melt extrusion is 99%-99.9% of the total mass.

[0048] S04: Spinning fibers from the TPEE mixed with the antioxidant. In this step, a spinning manifold is used for spinning. The spinning manifold can be a common device in the prior art. First, the TPEE that has been melt-extruded and mixed with an antioxidant is fed into the spinning manifold. The main function of the spinning manifold is to keep the TPEE melt at a constant temperature to ensure the fluidity and uniformity of the melt. The heating of the manifold and the melt pipeline is usually heated by a heat-conducting steam cycle generated by an electric heating furnace. The melt is evenly distributed to each spinning position in the spinning manifold through a melt distribution pipe to ensure that the melt reaches the same distance at each spinning position to ensure uniform melt viscosity, residence time and temperature, thereby ensuring uniform and stable spinning quality. The metering pump is responsible for quantitatively and evenly pressing the melt into the spinneret assembly. In this process, the mechanical impurities and agglomerated particles in the TPEE melt are further filtered by the filter screen and filter sand in the assembly, and further fully mixed in the assembly to prevent differences in temperature viscosity. As the melt passes through the high-resistance filter screen and filter sand under high pressure, the melt produces an extremely high shear rate, which not only improves the flow properties of the melt, but also increases the melt temperature evenly and instantaneously, thereby ensuring the uniform quality of the ejected melt stream. Finally, the melt passes through the spinneret to form fibers. In this step, the TPEE temperature during spinning is 220-260°C.

[0049] S05: Blow air on the long side to cool the fiber. Blow air on the long side of the TPEE fiber to cool it down to a certain extent, that is, use the cooling air with a lower temperature for heat exchange to take away the heat released by the melt during condensation, so that the filaments can be properly cooled, which is convenient for subsequent stretching and shaping, ensuring the cooling, solidification and quality of the TPEE fiber, and also helping to improve production efficiency and save energy. Specifically, the long corridor used for cold cutting is 12 meters long; the temperature of the cold cutting air is 16-20℃; the side blowing air pressure is 580P. Through this cold cutting parameter, it helps to improve its breaking strength.

[0050] S06: Winding the cooled fiber onto the first hot roller for stretching, winding onto the second hot roller for shaping after stretching, winding onto the third hot roller for shaping after stretching, winding onto the fourth hot roller for shaping after stretching, and winding onto the fifth hot roller for shaping after stretching to form TPEE fully stretched silk fiber.

[0051] Specifically, the temperature of the first hot roller is 60-90°C, and the winding speed is 500-700m / min; the temperature of the second hot roller is 100-140°C; the stretching ratio is 1.2-1.4, and the winding speed is 600-850m / min; the temperature of the third hot roller is 60-100°C; the stretching ratio is 2.8-3.2, and the winding speed is 1800-2500m / min; the temperature of the fourth hot roller is 60-100°C; the stretching ratio is 1.01-1.02, and the winding speed is 1900-2600m / min; the temperature of the fifth hot roller is 100-140°C; the stretching ratio is 0.95-0.98, and the winding speed is 1900-2500m / min.

[0052] Through 5-stage traction and stretching, the orientation of TPEE fibers is improved, the orderliness of molecular arrangement is increased, the internal stress in the fibers is removed, and the risk of deformation and breakage in subsequent processing is reduced, thereby achieving the effect of improving its breaking strength.

[0053] Furthermore, after step S06, the following steps are also included:

[0054] S07: The TPEE fully drawn yarn is wound into a yarn cake and put into storage for use after quality inspection. By precisely controlling the winding formation, bad winding phenomena such as overlapping yarns can be prevented, ensuring smooth processing of the fiber in the subsequent process and improving production efficiency.

[0055] Furthermore, after step S07, the following steps are also included:

[0056] S08: Place the TPEE fully stretched silk fiber cake into the texturizing device, and perform heating and stretching, false twisting, cooling and shaping, and winding in sequence. Through this step, the TPEE fully stretched silk fiber is transformed into a stretched textured yarn (DTY) with relatively stable physical properties that can be directly used for weaving. This process increases the elasticity and strength of the TPEE fully stretched silk fiber. Preferably, the heating temperature of the upper temperature box of the texturizing device is controlled at 150-180°C, and the temperature of the lower temperature box is controlled at 70-110°C. By precisely controlling the temperature, the TPEE fully stretched silk fiber is stretched, deformed, and heat-shaped, ensuring the physical properties and dimensional stability of the TPEE fully stretched silk fiber.

[0057] Specifically, in the texturing process of step S07, the production speed is controlled at 400-600m / min. By controlling the appropriate production speed, the heating time of the TPEE fully stretched silk fiber in the texturing device is appropriate, and the physical properties and processing quality of the TPEE fully stretched silk fiber can be optimized to ensure the smooth progress of the texturing process. The stretching multiple is controlled between 1.01-1.3, which can effectively optimize the physical properties of DTY, such as strength and elongation. The D / Y ratio (the ratio of the surface speed of the friction disk to the speed of the silk strip leaving the false twister) is 1.4-2. At this ratio, it is conducive to stable production, reducing the generation of hairy silk and tight points, thereby ensuring the physical properties of the TPEE fully stretched silk fiber, and optimizing the twist, tension and deformation effect of the fiber.

[0058] The present invention also provides a modified thermoplastic elastomer multifilament, which is made by using the processing method of a modified thermoplastic elastomer multifilament described in any one of the above technical solutions.

[0059] Furthermore, the fineness of the TPEE fully drawn silk fiber after the treatment in step S06 is 70-600D, and the number of pores is 12-144F.

[0060] The following is a specific embodiment 1:

[0061] S11. Drying: Dry TPEE to meet spinning standards, with a moisture content of less than 0.02%

[0062] In step S12, the drying temperature of the TPEE is 80° C. and the drying time is 4 h.

[0063] S12, melting: putting TPEE into a screw extruder for melting and extrusion;

[0064] S13, mixing: using a conduit to introduce the antioxidant and TPEE into the spinning box respectively, and mixing them according to the proportion;

[0065] In step S13, the weight of the antioxidant is 0.5% of the total weight of the composite fiber, and the weight of the TPEE is 99.5% of the total weight of the composite fiber.

[0066] S14, Spinning: Use a spinning box to spin TPEE fiber and cool it; the temperature of the cold cut air is 16-20℃, and the side blowing air pressure is 580Pa.

[0067] In step S14, the TPEE temperature during spinning is 235°C.

[0068] S15, the temperature of the first hot roller is 75°C, the winding speed is 630m / min, the temperature of the second hot roller is 125°C, the stretching ratio is 1.25, and the winding speed is 790m / min; the temperature of the third hot roller is 55°C, the stretching ratio is 3, and the winding speed is 2375m / min; the temperature of the fourth hot roller is 55°C, the stretching ratio is 1.01, and the winding speed is 2398m / min; the temperature of the fifth hot roller is 55°C, the stretching ratio is 0.99, and the winding speed is 2388m / min;

[0069] In step S15, the winding speed is 2220 m / min; the size of the fiber is 100D, and the number of holes in the composite fiber is 24F;

[0070] S16, finished product: FDY fiber is wound into silk cakes, and stored in warehouse for use after quality inspection.

[0071] DTY stretching process: Temperature: the upper hot box temperature is controlled at 170℃, the lower hot box temperature is controlled at 100℃; the production speed is 500m / min, the stretching multiple is controlled between 1.2, and the D / Y ratio is 1.7.

[0072] The following is a comparison table of the physical properties of FDY, DTY and comparative examples obtained according to the processing method of Example 1:

[0073] Line density Breaking strength Elongation at break Curl shrinkage Dry heat shrinkage Example 1 FDY 138dtex 4.0cn / dtex 22％ / 30％ Example 1DTY 114dtex 3.8cn / dtex 25％ 45％ 20％ Comparative Example 114dtex 2.8cn / dtex 30％ 38％ 20％

[0074] It can be seen from the table that the breaking strength of the FDY fiber after steps S11-S15 reaches 4.0 cn / dtex, which is higher than the elastic fiber (3.2 cN / dtex) currently on the market, and after the elasticization in step S16, the breaking strength of the DTY fiber is still 3.8 cn / dtex. On the basis of the breaking strength being much higher than that of the existing elastic fiber, it also has a breaking elongation of 25%, a curling shrinkage of 45%, and a dry heat shrinkage of 20%. Therefore, the modified thermoplastic elastomer multifilament obtained by the processing method of the present invention can control the strength of the thermoplastic elastomer multifilament to be greater than 4.0 cN / dtex, which is equivalent to conventional polyester DTY and 25-35% higher than other elastomer fibers. It can stably control the stability of the dry heat shrinkage of the controller, and the subsequent manufacturing dimensional stability is controllable.

[0075] The elastomeric multifilament produced by the above technical solution has a high breaking strength of >4.0cn / dtex. At the same time, the elasticized product has a high curl shrinkage rate that can be maintained above 40%, and can be directly used for weaving high-end fabrics to avoid the disadvantages of using spandex.

[0076] The invention adopts a stepwise stretching method, and then performs low-temperature relaxation and shaping, and finally performs two stretching shaping steps to stably control the dry heat shrinkage of the yarn within a range of 20±2%, thereby solving the problem of poor size control of spandex fabrics.

[0077] It should be noted that, although the above embodiments have been described in this article, the patent protection scope of the present invention is not limited thereby. Therefore, based on the innovative concept of the present invention, changes and modifications made to the embodiments described herein, or equivalent structures or equivalent process changes made by using the specification of the present invention, directly or indirectly applying the above technical solutions to other related technical fields are all included in the patent protection scope of the present invention.

Claims

1. A method for processing modified thermoplastic elastomer multifilament, characterized in that: The following steps are involved: S01: Dry TPEE to meet spinning standards; S02: putting the dried TPEE into a screw extruder for melt extrusion; S03: Use a conduit to introduce the antioxidant and the TPEE after melt extrusion into the spinning box respectively, and mix them in a certain proportion; S04: spinning fibers from TPEE mixed with an antioxidant; S05: Long side blowing cold cutting to cool the fiber; S06: Winding the cooled fiber onto the first hot roller for stretching, winding onto the second hot roller for shaping after stretching, winding onto the third hot roller for shaping after stretching, winding onto the fourth hot roller for shaping after stretching, and winding onto the fifth hot roller for shaping after stretching to form TPEE fully stretched silk fiber.

2. The method for processing a modified thermoplastic elastomer multifilament according to claim 1, characterized in that: After step S06, the following steps are also included: S07: Wind the TPEE fully drawn silk fiber into silk cakes, and store them in warehouse for use after quality inspection.

3. The method for processing a modified thermoplastic elastomer multifilament according to claim 2, characterized in that: After step S07, the following steps are also included: S08: Place the TPEE fully drawn silk fiber cake into the texturizing device, and perform heating and drawing, false twisting, cooling and shaping, and winding in sequence.

4. The method for processing modified thermoplastic elastomer multifilament according to claim 3, characterized in that: In step S08: The upper temperature box of the texturizing device is heated at 150-180°C, and the lower temperature box is heated at 70-110°C; and / or The production speed is controlled at 400-600m / min; and / or The stretching ratio is controlled between 1.01-1.3; and / or The D / Y ratio is 1.4-2.

5. The method for processing modified thermoplastic elastomer multifilament according to claim 1, characterized in that: The drying temperature in step S01 is 80-110° C., and the drying time is 4-8 hours.

6. The method for processing modified thermoplastic elastomer multifilament according to claim 1, characterized in that: The input mass of the antioxidant in step S03 is 0.1%-1% of the total mass, and the input mass of the TPEE after melt extrusion is 99%-99.9% of the total mass.

7. The method for processing modified thermoplastic elastomer multifilament according to claim 1, characterized in that: In step S05: The long corridor length for cold cutting is 12 meters; and / or The temperature of the cold wind is 16-20℃; and / or The side wind pressure is 580Pa.

8. The method for processing modified thermoplastic elastomer multifilament according to claim 1, characterized in that: In step S06: the temperature of the first hot roller is 60-90°C, the winding speed is 500-700m / min, the temperature of the second hot roller is 100-140°C; the stretching ratio is 1.2-1.4, and the winding speed is 600-850m / min; the temperature of the third hot roller is 60-100°C; the stretching ratio is 2.8-3.2, and the winding speed is 1800-2500m / min; the temperature of the fourth hot roller is 60-100°C; the stretching ratio is 1.01-1.02, and the winding speed is 1900-2600m / min; the temperature of the fifth hot roller is 100-140°C; the stretching ratio is 0.95-0.98, and the winding speed is 1900-2500m / min.

9. A modified thermoplastic elastomer multifilament, characterized in that: The modified thermoplastic elastomer multifilament is made by the processing method of any one of claims 1 to 9.

10. The modified thermoplastic elastomer multifilament according to claim 9, characterized in that: The fineness of the TPEE fully drawn silk fiber after the treatment in step S06 is 70-600D, and the number of pores is 12-144F.