Elastic fiber as well as preparation method and fabric thereof
By introducing TPU material into POE fibers, a mixed structure of polar and non-polar segments is formed, which improves the strength and toughness of the fibers, solves the breakage problem of POE fibers during spinning, and realizes the production of high-quality, stable monofilament fibers.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2026-01-13
- Publication Date
- 2026-04-21
AI Technical Summary
Existing POE fibers are prone to breakage during the spinning process, which affects the final properties and application range of the fibers.
By employing a hybrid structure of polyolefin elastomer and thermoplastic polyurethane elastomer, the strength and toughness of the fiber are enhanced through the synergistic effect of polar and non-polar segments. Furthermore, by utilizing the phase transition characteristics in response to temperature, the Young's modulus of the fiber changes with temperature, thus solving the fiber breakage problem.
It has achieved the production of high-quality, stable-performance monofilament elastic fibers with the characteristics of hardening when cold and softening when hot, which improves the fiber's breaking strength and elongation at break and solves the problem of fiber breakage during monofilament spinning.
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Figure CN121896750A_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of textile technology, and in particular to an elastic fiber, its preparation method, and its fabric. Background Technology
[0002] With increasing market demand, the functional requirements for textile fabrics are becoming higher and higher. Polyolefin elastomer (POE), as a new type of thermoplastic elastomer material, has the property that its hardness changes with temperature, making it a promising material for applications in the fiber industry.
[0003] Most existing POE fibers are produced by multi-filament spinning. It remains difficult to apply them to monofilament spinning and form stable, high-quality fibers. For example, fiber breakage is prone to occur during the spinning process, which affects the final performance and application range of the fiber. Summary of the Invention
[0004] This application aims to address at least one of the technical problems existing in the prior art. To this end, this application proposes an elastic fiber, a method for preparing the same, and a fabric thereof, to solve the fiber breakage problem that easily occurs during the spinning process of POE monofilament fibers in the prior art.
[0005] In a first aspect, this application provides an elastic fiber, wherein the raw materials of the elastic fiber include polyolefin elastomer materials and thermoplastic polyurethane elastomer materials; wherein, The soft segments of the polyolefin elastomer material have temperature-responsive phase transition characteristics, so that the Young's modulus of the elastic fiber changes with temperature; and the polyolefin elastomer material has at least one nonpolar segment. The thermoplastic polyurethane elastomer material has at least one polar chain segment; The elastic fiber has a mixed structure of polar segments and non-polar segments. In at least some embodiments of this application, The thermoplastic polyurethane elastomer material has a mass content of 5%-10%.
[0006] In at least some embodiments of this application, The phase transition characteristics of the soft segments of the polyolefin elastomer material include: at a first temperature, the soft segments of the polyolefin elastomer material are in a glassy state; at a second temperature, the soft segments of the polyolefin elastomer material are in a highly elastic state; wherein the first temperature is lower than the second temperature.
[0007] In at least some embodiments of this application, The first temperature is 0-10℃, and the Young's modulus of the elastic fiber is greater than or equal to 550 MPa; and / or, The second temperature is 23-45℃, and the Young's modulus of the elastic fiber is less than or equal to 25 MPa.
[0008] In at least some embodiments of this application, The polyolefin elastomer material is a copolymer elastomer structure composed of ethylene and octene or ethylene and butene; in the molecular chain of the copolymer elastomer structure, the octene segment or butene segment is used as a soft segment, and the ethylene segment is used as a physical crosslinking point.
[0009] In at least some embodiments of this application, The crystalline regions of the elastic fibers serve as physical crosslinking points, and the thermoplastic polyurethane elastomer material provides entropy elasticity in the soft segments.
[0010] In at least some embodiments of this application, The elastic fiber has a core-shell structure comprising a skin layer and a core layer, wherein the thermoplastic polyurethane elastomer serves as the material of the skin layer and the polyolefin elastomer material serves as the material of the core layer.
[0011] In at least some embodiments of this application, The cross-sectional area of the core layer accounts for 70-90% of the total cross-sectional area of the elastic fiber, and the cross-sectional area of the sheath layer accounts for 10-30% of the total cross-sectional area of the elastic fiber.
[0012] In at least some embodiments of this application, The elastic fiber has an anti-stick coating on its surface.
[0013] In a second aspect, this application provides a method for preparing elastic fibers as described in any one of the first aspects, the method comprising: Elastic fibers are obtained by melt spinning polyolefin elastomer materials and thermoplastic polyurethane elastomer materials; wherein, The soft segments of the polyolefin elastomer material have temperature-responsive phase transition characteristics, so that the Young's modulus of the elastic fiber changes with temperature; and the polyolefin elastomer material has at least one nonpolar segment. The thermoplastic polyurethane elastomer material has at least one polar chain segment; The elastic fiber has a mixed structure of polar segments and non-polar segments.
[0014] In at least some embodiments of this application, The process of melt spinning polyolefin elastomer material and thermoplastic polyurethane elastomer material to obtain elastic fibers includes: Polyolefin elastomer material and thermoplastic polyurethane elastomer material are mixed, melt-extruded, and cooled to obtain nascent fibers; The nascent fibers are stretched and shaped sequentially to obtain elastic fibers.
[0015] In at least some embodiments of this application, The method further includes: Polyolefin elastomer material as core material and thermoplastic polyurethane elastomer material as skin material are melted separately, then co-extruded and cooled to obtain nascent fibers with a core-skin structure. The nascent fibers with a core-sheath structure are stretched and shaped sequentially to obtain elastic fibers with a core-sheath structure.
[0016] In at least some embodiments of this application, The stretching is performed at least twice; and the stretching temperature meets any of the following conditions: The stretching is performed at 40℃-90℃; No heating is performed during the stretching process. In at least some embodiments of this application, The shaping includes: The stretched nascent fibers are then cooled and shaped, or subjected to heat treatment and cooling in sequence.
[0017] In at least some embodiments of this application, The method further includes treating the elastic fiber with an anti-sticking treatment liquid to give the surface of the elastic fiber an anti-sticking coating.
[0018] In a third aspect, a fabric comprises the elastic fibers described in any of the first aspects.
[0019] In at least some embodiments of this application, The fabric is formed by weaving a mixture of the elastic fibers and the base fibers in a certain proportion.
[0020] In at least some embodiments of this application, The ratio is (10:90) - (90:10).
[0021] The above-described technical solutions of this application have at least one or more of the following beneficial effects: In implementing the technical solution of this application, a thermoplastic polyurethane elastomer material is introduced on the basis of the polyolefin elastomer material. Through the synergy of the polar chain segments of the polyolefin elastomer material and the non-polar chain segments of the thermoplastic polyurethane elastomer material, the strength of the formed elastic fiber is improved, thereby achieving the improvement of the polyolefin elastomer material. That is, through the phase transition characteristics of the temperature response of the polyolefin elastomer material, the formed elastic fiber has the characteristic that the Young's modulus changes with temperature. At the same time, by adding the thermoplastic polyurethane elastomer material, the breaking strength and breaking elongation of the formed elastic fiber are improved, solving the fiber breakage problem in the monofilament spinning process, and realizing the production of high-quality, stable-performance monofilament elastic fiber.
[0022] Additional aspects and advantages of this application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of this application. Attached Figure Description
[0023] The disclosure of this application will become more readily understood with reference to the accompanying drawings. It will be readily understood by those skilled in the art that these drawings are for illustrative purposes only and are not intended to limit the scope of protection of this application. Furthermore, similar numbers in the drawings are used to denote similar components, wherein: Figure 1 This is a schematic diagram of the cross-sectional structure of an elastic fiber according to an embodiment of this application; Figure 2 This is a schematic flowchart of the main steps of a method for preparing elastic fibers according to an embodiment of this application; Figure 3 This is a schematic flowchart illustrating the specific steps of a method for preparing elastic fibers according to an embodiment of this application. Detailed Implementation
[0024] Some embodiments of this application are described below with reference to the accompanying drawings. Those skilled in the art should understand that these embodiments are merely illustrative of the technical principles of this application and are not intended to limit the scope of protection of this application.
[0025] This application provides an elastic fiber, the raw materials of which include polyolefin elastomer materials and thermoplastic polyurethane elastomer materials; wherein, The soft segments of the polyolefin elastomer material have temperature-responsive phase transition characteristics, so that the Young's modulus of the elastic fiber changes with temperature; and the polyolefin elastomer material has at least one nonpolar segment. The thermoplastic polyurethane elastomer material has at least one polar chain segment; The elastic fiber has a mixed structure of polar segments and non-polar segments. This can be understood as introducing a certain amount of thermoplastic polyurethane elastomer (TPU) into polyolefin elastomer (POE). The polar segments of TPU and the non-polar segments of POE are blended to form a high-strength mixed structure, which can significantly improve the strength and ductility of polyolefin elastomer monofilament fibers, thereby modifying the polyolefin elastomer monofilament fibers and completely eliminating the phenomenon of traditional polyolefin elastomer melts "breaking when pulled". At the same time, the temperature-responsive phase transition characteristics of POE materials can make the formed elastic fibers have the characteristic that the Young's modulus changes with temperature. The temperature-responsive phase transition characteristics can be understood as POE materials having a glass transition temperature (Tg), at which they can transform from a glassy state to a highly elastic state.
[0026] In the embodiments of this application, a thermoplastic polyurethane elastomer is introduced into the polyolefin elastomer material. By synergistically combining the polar segments of the polyolefin elastomer material with the non-polar segments of the thermoplastic polyurethane elastomer material, the strength of the formed elastic fiber is improved, thereby achieving an improvement on the polyolefin elastomer material. Specifically, the phase transition characteristics of the polyolefin elastomer material in response to temperature enable the formed elastic fiber to have the characteristic that the Young's modulus changes with temperature. At the same time, by adding the thermoplastic polyurethane elastomer material, the breaking strength and breaking elongation of the formed elastic fiber are improved, solving the fiber breakage problem during monofilament spinning. This results in the production of high-quality, stable-performance monofilament elastic fibers that can be directly applied to finished products such as fabrics.
[0027] In one embodiment, the mass content of thermoplastic polyurethane elastomer material is 5%-10%. This proportion can improve melt strength and solve the problem of POE monofilament breakage through the synergy of polar and non-polar segments; at the same time, it ensures that the adaptive properties of the elastic fibers formed by POE (the property of Young's modulus changing with temperature) are not masked, which is the core factor in balancing strength and adaptability. In this application, 5% is preferred.
[0028] In one embodiment, the phase transition characteristics of the soft segments of the polyolefin elastomer material include: at a first temperature (lower than a second temperature), the soft segments of the polyolefin elastomer material are in a glassy state, which imparts a high modulus to the formed elastic fiber, resulting in a high hardness of the elastic fiber; at a second temperature, the soft segments of the polyolefin elastomer material are in a highly elastic state, which reduces the modulus and hardness of the formed elastic fiber, thereby giving the obtained elastic fiber the characteristic of hardening when cold and softening when hot.
[0029] In one specific embodiment, the first temperature is 0-10℃, the Young's modulus of the elastic fiber is greater than or equal to 550 MPa, and the elasticity is low and the hardness is high; and / or, the second temperature is 23-45℃, the Young's modulus of the elastic fiber is less than or equal to 25 MPa, and the elasticity is high and the hardness is low.
[0030] In one specific embodiment, the polyolefin elastomer material is a copolymer elastomer structure composed of ethylene and octene or ethylene and butene, i.e., POE is formed by copolymerizing ethylene and octene (or butene) through metallocene catalysis. In the molecular chain of the copolymer elastomer structure, the octene segment or butene segment is used as a soft segment, and the ethylene segment is used as a physical crosslinking point. That is, the octene segment in the molecular chain provides flexibility, and the ethylene segment forms a crystalline region as a physical crosslinking point. The physical crosslinking structure enables the material to quickly recover its original shape after being deformed by force.
[0031] In one specific implementation, the crystalline regions of the elastic fibers serve as physical crosslinking points, while the thermoplastic polyurethane elastomer material provides entropy elasticity in the soft segments. Together, they can significantly reduce compression set.
[0032] In one embodiment, reference Figure 1 The elastic fiber has a core-sheath structure comprising a sheath and a core layer. Thermoplastic polyurethane elastomer serves as the material for the sheath, while polyolefin elastomer serves as the material for the core layer. The thermoplastic polyurethane elastomer material, acting as the sheath 200, increases the fiber's strength, toughness, and elasticity. Simultaneously, by wrapping the polyolefin elastomer material in the sheath 200, it improves wear resistance while retaining the polyolefin elastomer's properties of hardening when cold and softening when hot (Young's modulus changes with temperature), effectively solving the problem of easy breakage of monofilaments formed from polyolefin elastomer material.
[0033] In one possible implementation, the cross-sectional area of the core layer 100 accounts for 70-90% of the total cross-sectional area of the elastic fiber, and the cross-sectional area of the sheath layer 200 accounts for 10-30% of the total cross-sectional area of the elastic fiber. This application primarily modifies fibers made of polyolefin elastomer material, retaining the deformation characteristics of polyolefin elastomer material—hardening when cold and softening when hot—while the core layer 100, made of polyolefin elastomer material, is wrapped by the sheath layer 200. Utilizing the high elasticity and wear resistance of thermoplastic polyurethane elastomer material, the resulting elastic fiber is less prone to breakage. Based on this, to retain the properties of polyolefin elastomer, the area ratio of the core layer 100 is set larger than that of the sheath layer 200. It should be understood that in actual manufacturing, the area ratios of the sheath layer 200 and the core layer 100 can be adjusted according to specific requirements for the fiber (e.g., different requirements for elasticity, strength, deformation characteristics, etc.), and this application does not impose specific limitations in this regard.
[0034] In one embodiment, the elastic fiber surface has an anti-stick coating. The anti-stick coating reduces the static friction coefficient between monofilaments, solving the problems of winding adhesion and unwinding fuzz. The anti-stick coating can be a PU anti-stick coating.
[0035] Further, refer to Figure 2This application provides a method for preparing the elastic fiber as described above, the method comprising: Elastic fibers are obtained by melt spinning polyolefin elastomer materials and thermoplastic polyurethane elastomer materials; wherein, The raw materials for the elastic fibers include polyolefin elastomer materials and thermoplastic polyurethane elastomer materials; wherein, The soft segments of the polyolefin elastomer material have temperature-responsive phase transition characteristics, so that the Young's modulus of the elastic fiber changes with temperature; and the polyolefin elastomer material has at least one nonpolar segment. The thermoplastic polyurethane elastomer material has at least one polar chain segment; The elastic fiber has a mixed structure of polar segments and non-polar segments.
[0036] It is understandable that the melting process allows polyolefin elastomer materials and thermoplastic polyurethane elastomers to be blended to form a mixed structure. During the blending process, the polar segments of thermoplastic polyurethane elastomers and the non-polar segments of POE work together to improve melt strength and solve the problem of easy monofilament breakage of polyolefin elastomer materials. At the same time, the soft segments of polyolefin elastomer materials have temperature-responsive phase transition characteristics. Through TPU blending, the soft segment characteristics are retained so that the resulting elastic fibers have adaptive characteristics (Young's modulus changes with temperature).
[0037] In one embodiment, a method for preparing an elastic fiber specifically includes: The thermoplastic polyurethane elastomer material and the polyolefin elastomer material were dried separately. The dried raw materials are mixed and then fed into a screw extruder for plasticization. The spinning melt obtained after plasticization by a screw extruder is fed to a spinneret, extruded through the inner ring of the spinneret, and then cooled by ice water to form filaments, thus obtaining nascent fibers. The nascent fibers are stretched and shaped sequentially to obtain elastic fibers.
[0038] The drying process can be carried out using a dryer. The drying temperature for thermoplastic polyurethane elastomer materials and polyolefin elastomer materials is 60℃-90℃. The drying temperatures for the two materials can be the same or different. Under normal circumstances, the drying temperature of thermoplastic polyurethane elastomer materials is lower than that of polyolefin elastomer materials.
[0039] The temperature of each heating zone in the screw extruder ranges from 180℃ to 280℃. The screw extruder speed is 25-35 r / min. These can be adjusted according to the proportion of material used. The temperatures of each heating zone and the screw extruder speed can be the same or different.
[0040] Ideally, there should be no difference in extrusion between the inner and outer rings of the spinneret. However, in actual physical processes, due to differences in melt flow paths and pressure distribution, inherent differences exist. The inner ring, with its shorter flow path, lower flow resistance, and shorter melt residence time, may exhibit a higher flow rate and larger output, resulting in coarser nascent fibers. Therefore, to improve the breaking strength of monofilament fibers, the inner ring of the spinneret is chosen for melt extrusion. It should be understood that the spinneret used in this application can be any conventional spinneret, and no specific restrictions are imposed.
[0041] In one embodiment, the method for preparing an elastic fiber provided in this application specifically includes: Polyolefin elastomer material as core material and thermoplastic polyurethane elastomer material as skin material are dried separately. The dried raw materials are fed into a screw extruder for plasticization. The spinning melt obtained after plasticization by the screw extruder is sent to the spinneret, where the core material is placed in the inner ring of the spinneret for extrusion and the sheath material is placed in the outer ring of the spinneret for extrusion. It is then cooled by ice water to form filaments, thus obtaining nascent fibers with a core-sheath structure. The nascent fibers are stretched and shaped sequentially to obtain elastic fibers.
[0042] This can be understood as follows: the polyolefin elastomer material and the thermoplastic polyurethane elastomer material are not initially mixed and fused together, but are instead melt-spun as materials with different fiber structures and extruded together through a spinneret.
[0043] The drying process can be carried out using a dryer. The drying temperature for thermoplastic polyurethane elastomer materials and polyolefin elastomer materials is 60℃-90℃. The drying temperatures for the two materials can be the same or different. Under normal circumstances, the drying temperature of thermoplastic polyurethane elastomer materials is lower than that of polyolefin elastomer materials.
[0044] In this embodiment, the heating zones of the screw extruder are heated to 180℃-280℃. Since the thermoplastic polyurethane elastomer and the polyolefin elastomer are plasticized separately in the screw extruder, the heating zone temperatures and rotation speeds are set differently for the two materials. Typically, the temperature and rotation speed settings for the thermoplastic polyurethane elastomer are higher than those for the polyolefin elastomer. For the same material, the heating zone temperatures can be the same or different.
[0045] In this process, the inner ring of the spinneret is used for core material extrusion, and the outer ring is used for skin material extrusion, forming a melt stream with a core-skin structure. It should be understood that the spinneret used in this application can be any spinneret used in conventional melting processes, and no specific limitations are imposed.
[0046] In the above embodiments, the stretching process affects the breaking strength and elongation at break of the formed elastic fibers. In one specific embodiment, the stretching temperature can be between 40°C and 90°C; specifically, stretching can be performed using a hot water steam oven. Heating and stretching can improve the breaking strength of the formed elastic fibers. In another possible embodiment, the stretching process can also be performed without heating, and the cooled nascent fibers can be stretched directly, which can improve the adhesion problem.
[0047] In one possible implementation, the number of stretching cycles is set to at least two. Two or more stretching cycles can optimize molecular orientation and significantly improve fiber strength.
[0048] In one or more embodiments, the shaping process includes: cooling and shaping the stretched nascent fibers, or sequentially performing heat treatment shaping and cooling shaping. This can be understood as either directly selecting cooling shaping after stretching, or performing heat treatment shaping followed by cooling shaping. Direct single cooling shaping is suitable for scenarios with low shrinkage requirements, preserving basic elasticity. Although nascent fibers that have undergone multiple stretches have high strength, they also have high shrinkage. To lower their shrinkage temperature, heat treatment is performed first to reduce the fiber shrinkage temperature; furthermore, because the fiber viscosity is high after stretching, cooling shaping followed by rapid ice water shaping balances orientation and crystallinity, increasing the material's resilience. For example, in a specific embodiment, two heating and stretching processes are used, followed by heat treatment shaping and cooling shaping; after cooling, the nascent fibers undergo rapid freezing to solidify molecular orientation, followed by a second heating and stretching to achieve controllable orientation near the Tg, and then rapid cooling (using ice water) to achieve optimal balance between orientation and crystallinity, reducing fiber breakage rate.
[0049] In one or more embodiments, the nascent fibers can be subjected to anti-sticking treatment and winding after shaping. Specifically, the anti-sticking treatment can be performed by coating with a PU anti-sticking liquid and instantly curing it, so that a PU anti-sticking coating is formed on the shaped fibers, which can reduce the static friction coefficient between monofilaments and completely solve the problems of winding adhesion and unwinding fuzz.
[0050] To illustrate and verify the preparation method of the elastic fiber and the properties of the obtained elastic fiber, the following examples and comparative examples are provided.
[0051] Example 1 refer to Figure 3 A method for preparing elastic fibers, comprising: 1) Set component A to TPU material and component B to POE material; the mass ratio of component A is 5%; 2) Place components A and B separately into a dryer for 4-5 hours for dehumidification and drying; component A at 80℃ and component B at 90℃. 3) The dried raw materials are mixed manually or mechanically; 4) After mixing, the raw materials are added to the screw extruder together. The temperature of each heating zone is 255℃, the screw speed is 30r / min, and after melting, they are sent to the spinneret assembly for inner ring extrusion metering. 5) After melting, the fibers are sent to the spinneret assembly, where they are extruded and metered in the inner ring. They are then cooled by ice water to form filaments, which are then separated by hand. 6) The process involves stretching the material in a 60℃ hot water steamer, followed by further hot stretching in a 60℃ high-temperature hot water steamer to complete the secondary stretching. 7) Heat setting treatment, followed by adding ice water for further setting; 8) Finally, the PU emulsion is coated and instantaneously cured (completed within 0.5 seconds before winding), then wound up. After the finished product is unwound, it is left to stand in the balancing workshop for 2 days to obtain elastic fibers.
[0052] Example 2 The difference between this embodiment and Embodiment 1 is that the mass ratio of component A is 8%, while the other material selection parameters, preparation conditions and processes are the same.
[0053] Example 3 The difference between this embodiment and Embodiment 1 is that the mass ratio of component A is 10%, while the other material selection parameters, preparation conditions and processes are the same.
[0054] Example 4 The difference between this embodiment and embodiment 1 is that the stretching temperature in step 6) is 40°C, while the other material selection parameters, preparation conditions and processes are the same.
[0055] Example 5 The difference between this embodiment and embodiment 1 is that the stretching temperature in step 6) is 90°C, while the other material selection parameters, preparation conditions and processes are the same.
[0056] Example 6 The difference between this embodiment and embodiment 1 is that step 6) does not involve heating and stretching, while the other material selection parameters, preparation conditions and processes are the same.
[0057] Example 7 The difference between this embodiment and embodiment 1 is that step 6) involves three stretching operations, while the remaining material selection parameters, preparation conditions, and processes are the same.
[0058] Example 8 The difference between this embodiment and embodiment 1 is that step 6) involves three stretching operations without heating, while the other material selection parameters, preparation conditions, and processes are the same.
[0059] Example 9 The difference between this embodiment and embodiment 1 is that step 7) does not involve heat setting, but instead involves directly adding ice water for setting. The remaining material selection parameters, preparation conditions, and processes are the same.
[0060] Example 10 A method for preparing elastic fibers: 1) Component A is TPU material and serves as the outer skin material, and component B is POE material and serves as the core material; the mass ratio of component A is 5%; 2) Place components A and B separately into a dryer for 4-5 hours for dehumidification and drying; component A at 90℃ and component B at 60℃. 3) Add the dried raw materials to the screw extruder separately; 4) Component A is plasticized and melted by a screw extruder at 195°C and 7.6 rpm, and component B is plasticized and melted by a screw extruder at 180°C and 5.7 rpm, and then fed to the spinneret assembly. 5) After melting, the fibers are fed to the spinneret assembly with the core layer placed on the inner ring and the sheath layer placed on the outer ring for extrusion metering; then cooled by ice water to form filaments with a core-sheath structure to obtain nascent fibers, which are separated by hand. The cross-sectional area of the sheath layer accounts for 10% of the total cross-sectional area of the elastic fiber. 6) The process involves stretching the material in a 60℃ hot water steamer, followed by further hot stretching in a 60℃ high-temperature hot water steamer to complete the secondary stretching. 7) Heat setting treatment, followed by adding ice water for further setting; 8) Finally, the PU emulsion is coated and instantaneously cured, then rolled up. After the finished product is unrolled, it is left to stand in the balancing workshop for 2 days to obtain elastic fibers.
[0061] Example 11 The difference between this embodiment and Embodiment 10 is that the cross-sectional area of the cortex accounts for 20% of the total cross-sectional area of the elastic fiber, while the other material selection parameters, preparation conditions and processes are the same.
[0062] Example 12 The difference between this embodiment and Embodiment 10 is that the cross-sectional area of the skin layer accounts for 30% of the total cross-sectional area of the elastic fiber, while the other material selection parameters, preparation conditions and processes are the same.
[0063] Example 13 The difference between this embodiment and embodiment 10 is that step 6) does not involve heating and stretching, while the other material selection parameters, preparation conditions and processes are the same.
[0064] Example 14 The difference between this embodiment and embodiment 10 is that step 6) involves three stretching operations, while the remaining material selection parameters, preparation conditions, and processes are the same.
[0065] Example 15 The difference between this embodiment and embodiment 10 is that step 6) involves three stretching operations without heating, while the other material selection parameters, preparation conditions, and processes are the same.
[0066] Example 16 The difference between this embodiment and embodiment 10 is that step 7) does not involve heat setting, but instead involves directly adding ice water for setting. The remaining material selection parameters, preparation conditions, and processes are the same.
[0067] Comparative Example 1 The difference between this embodiment and Embodiment 1 is that the material only includes component B and does not include component A, while the other material selection parameters, preparation conditions and processes are the same.
[0068] Comparative Example 2 The difference between this embodiment and Embodiment 1 is that the mass ratio of component A is 3%, while the other material selection parameters, preparation conditions and processes are the same.
[0069] Comparative Example 3 The difference between this embodiment and Embodiment 1 is that the mass ratio of component A is 20%, while the other material selection parameters, preparation conditions and processes are the same.
[0070] Comparative Example 4 The difference between this embodiment and embodiment 1 is that step 6) involves a single stretching, while the remaining material selection parameters, preparation conditions, and processes are the same.
[0071] Comparative Example 5 The difference between this embodiment and embodiment 1 is that step 8) does not involve PU emulsion coating and instant curing, while the other material selection parameters, preparation conditions and processes are the same.
[0072] Comparative Example 6 The difference between this embodiment and Embodiment 10 is that the cross-sectional area of the skin layer accounts for 5% of the total cross-sectional area of the elastic fiber, while the other material selection parameters, preparation conditions and processes are the same.
[0073] Comparative Example 7 The difference between this embodiment and Embodiment 10 is that the cross-sectional area of the cortex accounts for 40% of the total cross-sectional area of the elastic fiber, while the other material selection parameters, preparation conditions and processes are the same.
[0074] The relevant parameter settings for the above embodiments and comparative examples are shown in Table 1 below.
[0075] Table 1: The Young's modulus of the elastic fibers obtained in Example 1 and Comparative Example 1 were measured at different temperatures, and the results are shown in Table 2: Table 2: As shown in Table 2, the Young's modulus of the elastic fibers obtained in Example 1 and Comparative Example 1 varies with temperature, and the temperature response range of the Young's modulus change is 0-10℃ and 23-45℃. The Young's modulus is higher at 0-10℃ and decreases at 23-45℃. That is, due to the characteristic that the soft segments of polyolefin elastomer (POE) are in a glassy state at 0-10℃ and enter a highly elastic state at 23-45℃, the addition of thermoplastic polyurethane elastomer (TPU) gives it the adaptive characteristic of Young's modulus changing with temperature.
[0076] Standardized strip tensile tests and related yarn material tests were performed on the elastic fibers obtained in each embodiment and comparative example, and the test results are shown in Table 3: Table 3: Table 3 shows the results of Examples 1-16 and Comparative Example 1. It can be seen that when a certain mass of thermoplastic polyurethane elastomer (TPU) is introduced into polyolefin elastomer (POE), the resulting elastic fibers still have the properties of hardening when cold and softening when hot (the Young's modulus increases at low temperature of 5°C, and the fiber hardens; at room temperature of 23°C, the Young's modulus drops sharply, and the fiber softens). As shown in Examples 1-3 and Comparative Example 1, introducing a certain mass of thermoplastic polyurethane elastomer (TPU) into polyolefin elastomer (POE) increases the tensile strength and elongation at break of the resulting elastic fibers. The tensile multiple of the elastic fibers under a 4MPa external force remains stable at 1-3 times, which improves the strength and toughness of the monofilament fibers, making them less prone to breakage. As shown in Examples 1-3 and Comparative Examples 1-3, the mass of thermoplastic polyurethane elastomer (TPU) needs to be controlled at 5-10%. If it is lower than 5%, as shown in Comparative Example 2, the effect on changing the tensile strength and elongation at break is limited and does not achieve the expected effect. If it is higher than 10%, it will affect the property of the resulting elastic fibers to harden when cold and soften when hot. A mass of 5-10% of thermoplastic polyurethane elastomer (TPU) can improve the strength of the elastic fibers while ensuring that the adaptive characteristics of the elastic fibers (Young's modulus changes with temperature) are not masked, thus balancing strength and adaptability. In this embodiment, the self-adaptive ability, tensile strength, and elongation at break of the elastic fiber are comprehensively considered, and the mass of the thermoplastic polyurethane elastomer (TPU) is preferably 5%. As shown in Examples 1 and 4-6, during the stretching process of melted polyolefin elastomer (POE) and thermoplastic polyurethane elastomer (TPU), the stretching temperature has a certain influence on the breaking strength and elongation at break of the formed elastic fibers. Within the range of 40-90℃, the higher the stretching temperature, the higher the breaking strength and elongation at break of the elastic fibers, that is, the higher the toughness of the elastic fibers, and the less likely the monofilament elastic fibers are to break. Although the toughness is reduced when stretching without heating, the coefficient of friction is low, reaching 0.21, indicating that stretching without heating can improve the adhesion of the formed elastic fibers. As shown in Examples 1, 7, 8 and Comparative Example 4, during the stretching process of melted polyolefin elastomer (POE) and thermoplastic polyurethane elastomer (TPU), the number of stretching cycles can affect the breaking strength and elasticity of the formed elastic fibers. The elastic fibers obtained by heating and stretching three times can achieve a stretching ratio of 1 under an external force of 4 MPa. Without heating, increasing the number of stretching cycles can also increase the breaking strength and elasticity. Only one stretching cycle results in a slightly lower breaking strength effect but a higher stretching ratio. Therefore, in this application, the number of stretching cycles is at least 2. As also shown in Examples 1, 6, and 8, heating and stretching can effectively reduce the fiber end ratio of the elastic fibers, from 20 times / 10 km to 1 time / 10 km. As can be seen from the results of Examples 1 and 9, in the process of heat treatment and shaping after melting polyolefin elastomer (POE) and thermoplastic polyurethane elastomer (TPU), the permanent deformation rate of elastic fibers can be improved by first heat treatment and then cooling, so that the permanent deformation rate is less than 3%. Although the fibers without heat setting retain better toughness and elasticity, their shrinkage performance is poor, and they are suitable for scenarios with low shrinkage requirements. As can be seen from the results of Example 1 and Comparative Example 5, after the obtained elastic fibers are shaped, coating with PU emulsion and instant curing treatment can significantly reduce the static friction coefficient between monofilaments and completely solve the problems of winding adhesion and unwinding fuzz. As can be seen from the results of Examples 10-12, using thermoplastic polyurethane elastomer (TPU) as the skin material and polyolefin elastomer (POE) as the core material, the resulting elastic fiber also has the property of hardening when cold and softening when hot, and has high breaking strength and elongation at break. The tensile multiple of the elastic fiber under an external force of 4MPa is stable at 1 to 3 times, which solves the problem of easy breakage of POE monofilament. As can be seen from Comparative Examples 6 and 7 and Examples 10-12, the cross-sectional area of the skin layer relative to the total cross-sectional area of the elastic fiber, i.e., the proportion of thermoplastic polyurethane elastomer (TPU) as the skin material, affects the breaking strength and elongation at break of the obtained elastic fiber. The higher the proportion of thermoplastic polyurethane elastomer (TPU), the better the toughness of the obtained elastic fiber and the less likely it is to break. However, when it is below 10%, the improvement effect is effective, while when it is above 30%, it will destroy the property of the fiber to harden when cold and cool when hot. Therefore, in this application, the proportion of thermoplastic polyurethane elastomer (TPU) as the skin material is controlled at 10-30%. Taking into account the adaptive properties and toughness balance, 10% is preferred. As can be seen from the results of Examples 13-16, the elastic fiber with a core-sheath structure obtained in Example 10 also has the same effect as in Examples 1-9 when the stretching, shaping and other conditions are changed. The repeated parts will not be described again. As can be seen from the results of Examples 1-16 and Comparative Example 1, introducing a certain mass of thermoplastic polyurethane elastomer (TPU) into polyolefin elastomer (POE) and using TPU as the skin material and POE as the core material both improve the permanent deformation rate of the elastic fibers. The permanent deformation of POE, which was originally 200%, was significantly reduced to below 25% after blending with TPU, thus improving its permanent resilience.
[0077] In summary, the above embodiments and comparative examples demonstrate that introducing TPU into POE materials not only provides adaptive properties that change morphology with temperature (hardening when cold and softening when hot: hardening at 0–10℃ and softening at 23–45℃), but also effectively improves the fiber's tensile strength, elongation at break, and resilience, eliminating the "breaks easily when pulled" phenomenon inherent in POE melt. Furthermore, during the preparation of elastic fibers, adjustments to the TPU mass ratio, stretching process, and setting process can further enhance fiber strength, elongation at break, and permanent resilience, as well as effectively improve adhesion issues.
[0078] Furthermore, embodiments of this application provide a fabric comprising the aforementioned elastic fibers.
[0079] As can be seen from the above embodiments, elastic fibers can be applied to fabrics, giving the fabrics high toughness and high strength. At the same time, they can provide deformation properties: hardening when cold, softening when hot, and permanent elasticity, and can be directly applied to shoe uppers, clothing, etc.
[0080] In one embodiment, the fabric can also be woven from a mixture of elastic fibers and base fibers in a specific ratio. Specifically, the ratio is (10:90) to (90:10), and the ratio of elastic fibers to base fibers can be adjusted and selected according to the required hardness and elasticity of the applied product. In this application, the base fiber includes one or more of nylon fibers, polyester fibers, elastic polyester fibers, or polyurethane fibers. Specifically, the polyester fiber can be polyester or cationic fiber; the polyurethane fiber can be TPU; and the elastic polyester fiber can be TPEE.
[0081] In one possible implementation, the weaving method includes one or more of warp knitting, weft knitting, or woven fabric. Among them, weft knitting includes fly knitting and circular knitting.
[0082] Based on the above implementation method, the fabric provided in this embodiment also has high strength and high toughness, and also has adaptability. It will harden in low temperature environment (such as 0-10℃) and provide a high flexural modulus (≥550MPa), and the fabric is not easily deformed. When the temperature rises to the surface temperature when the human body is in normal movement (23-45℃), the fabric softens and the flexural modulus drops sharply to below 25MPa, adapting to wearing needs and meeting the needs of multiple applications.
[0083] Furthermore, based on the above embodiments, this application provides a shoe upper, including the above-described elastic fibers or fabrics.
[0084] The significance of applying the aforementioned elastic fibers or fabrics to shoe uppers lies in addressing the numerous shortcomings of existing shoe upper materials in terms of comfort, fit, and durability. For example, a more snug fit is more beneficial for athletes in professional sports shoes. Currently, shoe uppers cannot adapt to changes in foot shape for a self-adaptive fit; this can be understood as the inability to dynamically adjust their fit based on ambient temperature and foot shape. Furthermore, existing shoe upper materials are prone to loosening and deformation after repeated wear, affecting the shoe's appearance and performance. In other words, they cannot provide optimal support and comfort in different usage scenarios, nor can they maintain good fit and shape stability over the long term. However, by applying the aforementioned elastic fibers or fabrics to shoe uppers, the upper material can achieve high comfort, high fit, and high durability, meeting higher demands for shoe uppers.
[0085] In one embodiment, the above-mentioned elastic fibers or fabrics are applied to the shoe upper, and the shoe upper can be directly woven into the shoe upper by means of weaving or other methods, so that the shoe upper material directly has many of the properties of the above-mentioned elastic fibers or fabrics. For specific properties, please refer to the above-described embodiments or examples, and repeated parts will not be described again.
[0086] In one embodiment, the upper can be woven from a mixture of elastic fibers and base fibers in a specific ratio. Specifically, the ratio is (10:90) to (90:10), and the ratio of elastic fibers to base fibers can be adjusted and selected according to the required hardness and elasticity of the product being applied.
[0087] The base fiber includes one or more of nylon fiber, polyester fiber, elastic polyester fiber or polyurethane fiber. Specifically, polyester fiber can be polyester or cationic fiber; polyurethane fiber can be TPU; and elastic polyester fiber can be TPEE.
[0088] The weaving method can employ machine-woven or knitted techniques, including warp knitting, weft knitting, or woven fabric, or a combination thereof. Weft knitting includes fly knitting and circular knitting. Through weaving techniques, the woven structure of the shoe upper becomes tighter and more uniform, improving its overall strength and durability. Simultaneously, machine-woven and knitted techniques can precisely weave an upper shape that conforms to the foot's shape and size, reducing gaps between the upper and the foot, and further enhancing the comfort and stability of the shoe upper with the help of elastic fibers.
[0089] Based on the above embodiments, by adjusting the ratio of elastic fibers to base fibers, specific functions and aesthetic effects of the shoe upper can be achieved according to different usage needs and shoe designs. For example, increasing the proportion of elastic fibers in key support areas of the shoe upper (such as the toe and heel) provides better support and shape retention; appropriately reducing the proportion of smart deformable fibers in softer areas of the shoe upper (such as the tongue and sides) maintains the softness and breathability of the upper.
[0090] One possible implementation involves using flyknit technology, mixing elastic fibers with nylon fibers in a 60:40 ratio. The fibers are then woven into a complex upper structure using a computer-controlled flyknit machine. Alternatively, 20% elastic fibers can be used in the toe and heel, employing techniques such as four-way ribbing (also called 1×1 rib knit, consisting of alternating front and back loops) and locking loops to increase stability and stiffness, providing support and better shape retention for the toe and heel. The remaining 50% elastic fibers are used in softer areas such as the tongue and sides of the upper to maintain softness and breathability, and to enhance the fit and contouring of the foot.
[0091] One possible implementation involves using circular knitting technology, mixing elastic fibers and polyester fibers in a 50:50 ratio. A seamless upper is formed through continuous knitting on a circular knitting machine. Specifically, in the tongue area of the upper, by adjusting the plain weave density and combining it with a four-way cross-knit, and by controlling the alternating weave of plain and rib stitches on the upper and lower needle beds, an upper with a plain-like front, floating threads on the reverse, and an internal ribbed skeleton is obtained. This also increases the proportion of elastic fibers, achieving a balance between stability and elasticity. In the softer areas of the upper, the softness and breathability are maintained, and the overall fit and wrapping performance of the upper around the foot is improved.
[0092] In one possible implementation, warp knitting technology is used to blend elastic fibers and nylon fibers in a 40:60 ratio. Through multi-axis knitting on a warp knitting machine, a jacquard weave is used for the outer layer; the middle layer uses monofilament connections to form a support structure; the bottom layer is simply a plain weave tightened, ultimately forming an upper with a slightly three-dimensional structure. In the toe area and other softer areas of the upper, the proportion of elastic elastomer fibers is increased to maintain the upper's softness and snug fit.
[0093] One possible implementation involves using a weaving technique, mixing elastic fibers with TPEE fibers in a 30:70 ratio. The weft and warp threads are interwoven on a loom to create a high-strength upper. Elastic fibers are used in the weft direction of the entire upper, employing a jacquard weave structure. The toe area uses a perforated structure to create ventilation, maintaining breathability and overall lightweight properties while allowing the entire upper to conform to the foot shape.
[0094] It is important to note that during the overall weaving process of the shoe upper, the ratio of elastic fibers to base fibers must be evenly distributed to achieve the softness and comfort of the upper.
[0095] Based on the above embodiments and implementation methods, the shoe upper in this application is woven using elastic fibers that harden when cold, soften when hot, and possess permanent elasticity, combined with weaving technology. Because this elastic fiber hardens in low-temperature environments (e.g., 0–10℃), providing a high flexural modulus (≥550MPa), the resulting shoe upper is stiff and not easily deformed, effectively maintaining the shoe's shape. When the temperature rises to the surface temperature during normal human movement (23–45℃), the elastic fiber softens, and the flexural modulus drops sharply to below 25MPa, allowing the resulting shoe upper to adapt to the curvature of the instep, resulting in even pressure distribution and greater comfort. Furthermore, this elastic fiber also possesses permanent elasticity, with a permanent deformation of less than 3% after a stretch-recovery cycle and high strength, ensuring that the shoe upper will not loosen or deform during long-term use, always conforming to the foot and remaining durable. Moreover, the elastic fiber's low density allows the resulting shoe upper to not only possess excellent functionality but also achieve a lightweight design, significantly improving wearing comfort and athletic performance.
[0096] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.
[0097] The various embodiments in this specification are described in a progressive manner. Similar or identical parts between embodiments can be referred to mutually. Each embodiment focuses on describing the differences from other embodiments. In particular, for system or system embodiments, since they are basically similar to method embodiments, the description is relatively simple, and relevant parts can be referred to the descriptions in the method embodiments. The systems and system embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs. Those skilled in the art can understand and implement this without creative effort.
[0098] Although embodiments of this application have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting this application. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of this application.
Claims
1. An elastic fiber, characterized in that, The raw materials for the elastic fibers include polyolefin elastomer materials and thermoplastic polyurethane elastomer materials; wherein, The soft segments of the polyolefin elastomer material have temperature-responsive phase transition characteristics, so that the Young's modulus of the elastic fiber changes with temperature; and the polyolefin elastomer material has at least one nonpolar segment. The thermoplastic polyurethane elastomer material has at least one polar chain segment; The elastic fiber has a mixed structure of polar segments and non-polar segments.
2. The elastic fiber according to claim 1, characterized in that, The thermoplastic polyurethane elastomer material has a mass content of 5%-10%.
3. The elastic fiber according to claim 1, characterized in that, The phase transition characteristics of the soft segments of the polyolefin elastomer material include: at a first temperature, the soft segments of the polyolefin elastomer material are in a glassy state; at a second temperature, the soft segments of the polyolefin elastomer material are in a highly elastic state; wherein the first temperature is lower than the second temperature.
4. The elastic fiber according to claim 3, characterized in that, The first temperature is 0-10℃, and the Young's modulus of the elastic fiber is greater than or equal to 550 MPa; and / or, The second temperature is 23-45℃, and the Young's modulus of the elastic fiber is less than or equal to 25 MPa.
5. The elastic fiber according to claim 3, characterized in that, The polyolefin elastomer material is a copolymer elastomer structure composed of ethylene and octene or ethylene and butene; in the molecular chain of the copolymer elastomer structure, the octene segment or butene segment is used as a soft segment, and the ethylene segment is used as a physical crosslinking point.
6. The elastic fiber according to claim 1, characterized in that, The crystalline regions of the elastic fibers serve as physical crosslinking points, and the thermoplastic polyurethane elastomer material provides entropy elasticity in the soft segments.
7. The elastic fiber according to claim 1, characterized in that, The elastic fiber has a core-shell structure comprising a skin layer and a core layer, wherein the thermoplastic polyurethane elastomer serves as the material of the skin layer and the polyolefin elastomer material serves as the material of the core layer.
8. The elastic fiber according to claim 7, characterized in that, The cross-sectional area of the core layer accounts for 70-90% of the total cross-sectional area of the elastic fiber, and the cross-sectional area of the sheath layer accounts for 10-30% of the total cross-sectional area of the elastic fiber.
9. The elastic fiber according to claim 1, characterized in that, The elastic fiber has an anti-stick coating on its surface.
10. A method for preparing an elastic fiber as described in any one of claims 1-9, characterized in that, The method includes: Elastic fibers are obtained by melt spinning polyolefin elastomer materials and thermoplastic polyurethane elastomer materials; wherein, The soft segments of the polyolefin elastomer material have temperature-responsive phase transition characteristics, so that the Young's modulus of the elastic fiber changes with temperature; and the polyolefin elastomer material has at least one nonpolar segment. The thermoplastic polyurethane elastomer material has at least one polar chain segment; The elastic fiber has a mixed structure of polar segments and non-polar segments.
11. The method for preparing elastic fibers according to claim 10, characterized in that, The process of melt spinning polyolefin elastomer material and thermoplastic polyurethane elastomer material to obtain elastic fibers includes: Polyolefin elastomer material and thermoplastic polyurethane elastomer material are mixed, melt-extruded, and cooled to obtain nascent fibers; The nascent fibers are stretched and shaped sequentially to obtain elastic fibers.
12. The method for preparing elastic fibers according to claim 10, characterized in that, The method further includes: Polyolefin elastomer material as core material and thermoplastic polyurethane elastomer material as skin material are melted separately, then co-extruded and cooled to obtain nascent fibers with a core-skin structure. The nascent fibers with a core-sheath structure are stretched and shaped sequentially to obtain elastic fibers with a core-sheath structure.
13. The method for preparing elastic fibers according to claim 11 or 12, characterized in that, The stretching is performed at least twice; and the stretching temperature meets any of the following conditions: The stretching is performed at 40℃-90℃; No heating is performed during the stretching process.
14. The method for preparing elastic fibers according to claim 11 or 12, characterized in that, The shaping includes: The stretched nascent fibers are then cooled and shaped, or subjected to heat treatment and cooling in sequence.
15. The method for preparing elastic fibers according to claim 10, characterized in that, The method further includes treating the elastic fiber with an anti-sticking treatment liquid to give the surface of the elastic fiber an anti-sticking coating.
16. A fabric, characterized in that, Includes the elastic fiber described in any one of claims 1-9.
17. The fabric according to claim 16, characterized in that, The fabric is formed by weaving a mixture of the elastic fibers and the base fibers in a certain proportion.
18. The fabric according to claim 17, characterized in that, The ratio is (10:90) - (90:10).