High-strength transparent monofilament, method for manufacturing the same, fabric, and article of footwear

Abstract

The application relates to the technical field of transparent monofilament, in particular to a high-strength transparent monofilament, a preparation method thereof, a fabric and a shoe product. The method comprises the following steps: providing dry transparent nylon chips; melt-extruding the dry transparent nylon chips to form nascent fibers; contacting the nascent fibers with a cooling medium to perform cooling treatment on the nascent fibers, so that cooled fibers are obtained; and performing drawing setting of the cooled fibers, wherein the drawing setting comprises at least one drawing and at least two heat setting which are performed in sequence, and the two heat setting are performed at temperatures higher and lower than the glass transition temperature of the nascent fibers in sequence. The high-performance transparent monofilament and the fabric made of the high-performance transparent monofilament can effectively balance high permeability and durable comfort.

Description

Technical Field

[0001] This invention relates to the field of transparent monofilament technology, and in particular to a high-strength transparent monofilament, its preparation method, fabric, and footwear. Background Technology

[0002] As consumer demand for footwear products continues to rise in terms of fashion, functionality, and personalization, transparent uppers, with their lightweight and visually clear appearance, have become an important design trend. However, existing transparent upper materials still have significant limitations in terms of processing performance, optical properties, and durability.

[0003] Firstly, at the material level, traditional transparent materials such as polyvinyl chloride (PVC) suffer from problems such as stiffness, yellowing, and aging, affecting wearing comfort and the durability of appearance. Although new polymer materials such as polyethylene terephthalate (PET) and thermoplastic polyurethane (TPU) have improved in terms of transparency, flexibility, and mechanical strength, when applied to shoe uppers, they are usually only used as embellishments in certain areas, making it difficult to achieve the comprehensive requirements of high transparency, high comfort, and high durability across the entire shoe upper.

[0004] In the pursuit of higher-performance transparent materials, transparent nylon has attracted attention due to its excellent optical transparency, good mechanical strength, and chemical resistance. However, in traditional understanding and application, this type of transparent nylon material is almost exclusively used in injection-molded products (such as lenses and windows). Developing it into continuous, highly transparent monofilaments through melt spinning technology and further applying it to the textile and apparel industry faces unique technological barriers.

[0005] Secondly, at the fiber processing level, the core challenge in achieving high transparency lies in the precise control of fiber crystal morphology. Conventional melt spinning processes mostly use air cooling for solidification and cooling. This method has a relatively slow and uneven cooling rate, which easily leads to coarse or unevenly distributed crystals inside the fiber, resulting in severe light scattering. This significantly increases the haze of the monofilament (usually much higher than 5%), failing to meet the high-transparency visual effect requirements of high-end applications.

[0006] For transparent nylon, its molecular structure designed to achieve high transparency (such as introducing side groups, copolymer units, or alicyclic structures to disrupt regularity and reduce crystallinity) brings optical advantages but also makes its spinning behavior different from conventional highly crystalline nylon resins (such as ordinary PA6 and PA66). In the traditional spinning process, after extrusion from the spinneret, the nascent transparent nylon fibers exhibit different rheological and relaxation behaviors than ordinary nylon during cooling and subsequent drawing stages, and are prone to severe shrinkage. Directly applying traditional spinning process parameters optimized for highly crystalline rigid nylon often leads to unstable fiber formation, easy breakage, easy re-adhesion, or irregular deformation, making it impossible to form continuous monofilaments with high strength, good transparency, and uniform appearance. This processing challenge has essentially hindered the effective expansion of transparent nylon from the injection molding field to the field of high-performance textile monofilaments, resulting in few mature commercially available high-performance transparent monofilament products made of transparent nylon and limiting innovation in downstream products.

[0007] Therefore, there is an urgent need in this field to overcome the bottleneck of melt spinning technology for transparent nylon and develop a preparation process that is compatible with its material properties in order to fill the market gap and meet the comprehensive performance requirements of transparent materials in high-end footwear and apparel and other fields. Summary of the Invention

[0008] To address the shortcomings of the prior art, this invention provides a high-strength transparent monofilament, its preparation method, fabric, and footwear.

[0009] The first aspect of the present invention provides a method for preparing a high-strength transparent monofilament, comprising the following steps: Dry, clear nylon slices are provided; The dried transparent nylon chips are melt-extruded to form nascent fibers; The nascent fibers are brought into contact with a cooling medium to cool them, thereby obtaining cooled fibers. The cooled fiber is drawn and set, the drawing and setting comprising at least one drawing and at least two heat setting processes performed sequentially, the two heat setting processes being performed successively at glass transition temperatures above and below the nascent fiber.

[0010] In a preferred embodiment of the present invention, the transparent nylon is selected from one or more of aliphatic transparent nylon, alicyclic transparent nylon, or semi-aromatic transparent nylon.

[0011] In a preferred embodiment of the present invention, the stretching and setting includes a first stretching, a first heat setting, a second stretching, a second heat setting, a third stretching, a third heat setting, and a fourth stretching performed sequentially.

[0012] In a preferred embodiment of the present invention, the first heat setting and the third heat setting are performed at a temperature higher than the glass transition temperature of the nascent fibers made from the transparent nylon chips, and the second heat setting is performed at a temperature lower than the glass transition temperature.

[0013] In a preferred embodiment of the present invention, the temperature of the first heat setting is 85°C to 95°C, the temperature of the second heat setting is 25°C to 35°C, and the temperature of the third heat setting is 115°C to 125°C.

[0014] In a preferred embodiment of the present invention, the cooling medium is water, and the cooling process is water cooling.

[0015] In a preferred embodiment of the present invention, the cooling process includes passing the nascent fibers sequentially through a first cooling zone and a second cooling zone, wherein the first cooling zone provides a first cooling temperature, the second cooling zone provides a second cooling temperature, and the second cooling temperature is higher than the first cooling temperature.

[0016] In a preferred embodiment of the invention, the temperature of the second cooling zone is configured to be higher than the temperature of the first heat setting.

[0017] A second aspect of the present invention provides a method for preparing a high-strength transparent monofilament, comprising the following steps: Dry, clear nylon slices are provided; The transparent nylon chips are melt-blended with functional additives, cooled, granulated, and dried to obtain modified chips; The modified chips are melt-extruded to form nascent fibers; The nascent fibers are brought into contact with a cooling medium to cool them, thereby obtaining cooled fibers. The cooled fiber is drawn and set, the drawing and setting comprising at least one drawing and at least two heat setting processes performed sequentially, the two heat setting processes being performed successively at glass transition temperatures above and below the nascent fiber.

[0018] In a preferred embodiment of the present invention, the functional additive includes one or more of a primary antioxidant, a secondary antioxidant, and an ultraviolet absorber; In a preferred embodiment of the present invention, the main antioxidant is a phenol-free hydroxylamine antioxidant, and its addition amount accounts for 0.3%-0.5% of the mass of the modified slices; In a preferred embodiment of the present invention, the auxiliary antioxidant is a thioester antioxidant, and its addition amount accounts for 0.1%-0.2% of the mass of the modified slices; In a preferred embodiment of the present invention, the ultraviolet absorber is a benzotriazole ultraviolet absorber, and its addition amount accounts for 0.2%-0.4% of the mass of the modified slice.

[0019] A third aspect of the present invention provides a high-strength transparent monofilament, which is prepared by the method described in the first aspect or the second aspect of the present invention.

[0020] In a preferred embodiment of the present invention, the high-strength transparent monofilament has a haze of ≤5%, a breaking strength of ≥4.0cN / dtex, and a breaking elongation of 25%-35%.

[0021] A fourth aspect of the present invention provides a fabric comprising the high-strength transparent monofilament described in the third aspect of the present invention.

[0022] A fifth aspect of the present invention provides a footwear article having an upper and a sole structure fixed to the upper, the upper including a woven component comprising at least one monofilament region formed of a high-strength transparent monofilament of the third aspect of the present invention, the at least one monofilament region having a shape.

[0023] The high-strength transparent monofilament preparation method provided by this invention optimizes the process, causing the nascent fiber to sequentially undergo three core stages: above, below, and then above its glass transition temperature. This process successfully solves the inherent problem of severe shrinkage and difficulty in shaping transparent nylon during spinning, while effectively suppressing unfavorable crystallization. The resulting monofilament possesses high transparency, high strength, high elasticity, and excellent resistance to yellowing, enabling the reliable application of this material in fields such as high-performance transparent shoe uppers for the first time.

[0024] Other features and beneficial effects of the invention will be set forth in the following description, and will be apparent in part from the description, or may be learned by practicing the invention. The objects of the invention and other beneficial effects may be realized and obtained by means of the structures particularly pointed out in the description and claims. Detailed Implementation

[0025] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are some embodiments of the present invention, but not all embodiments. The technical features designed in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0026] In the description of this invention, it should be noted that all terms used in this invention (including technical and scientific terms) have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains, and should not be construed as limiting the invention; it should be further understood that the terms used in this invention should be understood to have the same meaning as those in the context of this specification and in the relevant field, and should not be understood in an idealized or overly formal sense, except as expressly defined in this invention.

[0027] The first aspect of the present invention provides a method for preparing a high-strength transparent monofilament, comprising the following steps: Step 1: Provide dried, clear nylon slices; In an embodiment of the present invention, a thoroughly dried transparent nylon chip is provided, the purpose of which is to reduce the moisture content of the chip to an extremely low level, for example, below 0.2%, in order to prevent the decrease in molecular weight, fluctuation in melt viscosity and yellowing of the product due to hydrolysis during the subsequent high-temperature melting process, and to ensure the stability of the spinning process and the quality of the final product. It should be noted that "providing" in this application can refer to commercially available slices that meet the requirements, or to the product after drying the hygroscopic slices online or offline; the "drying" method includes, but is not limited to, vacuum oven drying, dehumidified air drying, fluidized bed drying, etc.; as for the form of the "slices": it is not limited to conventional slices, but can include solid forms such as granules and powders suitable for melt extrusion.

[0028] The transparent nylon described in this invention refers to a class of polyamide materials with high light transmittance, typically not less than 80% for visible light and generally less than 10% for haze. These materials achieve excellent optical transparency by disrupting the regularity of the molecular chains and inhibiting crystallization through molecular structure design (such as introducing side groups, copolymerization, or using alicyclic monomers). This results in an amorphous or low-crystallinity state. The scope encompasses aliphatic transparent nylons (such as transparent PA6 and transparent PA12), alicyclic transparent nylons, and semi-aromatic transparent nylons. This invention is particularly applicable to slices made from these transparent nylon materials suitable for melt spinning.

[0029] The dried transparent nylon chips described in this invention refer to transparent polyamide materials suitable for melt spinning that have undergone drying treatment and have extremely low moisture content. The transparent nylon is preferably an amorphous or low-crystallinity polyamide material, such as transparent PA6 or transparent PA66, which possess inherent high light transmittance. Before melt extrusion, the chips must be thoroughly dried to a moisture content below 0.5% (mass percentage), preferably below 0.2%. If the moisture content of the chips is too high, hydrolytic degradation is highly likely to occur during the subsequent high-temperature melting process, leading to a decrease in polymer molecular weight, fluctuations in melt viscosity, and potentially causing bubbles and yellowing, ultimately severely affecting the strength, transparency, and stability of the monofilament spinning process. The drying can be achieved using conventional methods in the art, such as treating the chips in a vacuum oven or dehumidifier at an appropriate temperature (e.g., 80℃-120℃) for a sufficient time (e.g., 6-12 hours) to ensure the moisture content meets the above requirements.

[0030] Step 2: Melt and extrude the dried transparent nylon chips to form nascent fibers; In an embodiment of the present invention, the dried chips are heated to above their melting temperature in an extruder (such as a twin-screw extruder) to completely melt them into a homogeneous melt, which is then extruded through a fiber forming device, preferably a spinneret with circular spinneret orifices, to form nascent fibers. This step realizes the transformation of the material from a solid state to a melt, and then to the initial morphology of fibers.

[0031] It should be noted that the equipment for achieving "melting" includes, but is not limited to, twin-screw extruders, single-screw extruders, and internal mixers combined with gear pumps. For the apparatus for "extrusion" and "forming nascent fibers": it can be a spinning assembly with one or more fiber forming channels, such as the spinneret listed in the embodiments of this invention. The spinneret's orifice shape is not limited to circular; it can also be triangular, trefoil-shaped, or other irregularly shaped orifices to increase gloss or feel.

[0032] Step 3: Contact the nascent fibers with a cooling medium to cool them and obtain cooled fibers; In embodiments of the present invention, the extruded nascent fibers are immediately brought into contact with a cooling medium for forced cooling to obtain cooled fibers. The cooling process is preferably water cooling, for example, passing the nascent fibers through a constant-temperature water flow or water bath. The purpose is to utilize the much higher thermal conductivity of a liquid medium (such as water) than that of a gas to quench the fibers. This rapid cooling speed quickly freezes the molten polymer chains, greatly suppressing the orderly arrangement and crystallization process of the molecular chains in the high-temperature region, which is beneficial for forming a predominantly amorphous structure. This is key to achieving high initial transparency of the monofilament. Compared to traditional air cooling, water cooling can more effectively reduce light scattering caused by uneven crystallization, thereby significantly reducing haze.

[0033] It should be noted that the type of "cooling medium" can be liquid, gas, or solid. Liquids can include, for example, water, aqueous solutions, or oil baths; gases can include, for example, cooling air, cryogenic air, or nitrogen; and solids can include, for example, cooling rollers. Furthermore, the "contact" methods claimed in this invention include, but are not limited to, water bath cooling, spray cooling, atomization cooling, air blowing cooling, and contact cooling rollers. Moreover, the number of cooling stages and temperature zones can be single-stage cooling or multi-stage gradient cooling, such as water cooling followed by air cooling, or a two-stage "quenching-warming" cooling system that starts at a low temperature and ends at a high temperature.

[0034] Step 4: Stretch and set the cooled fiber, the stretching and setting including at least one stretching and at least two heat setting operations performed sequentially, the two heat setting operations being performed successively at glass transition temperatures higher and lower than the nascent fiber.

[0035] In a preferred embodiment of the present invention, the stretching and setting includes at least a first stretching, a first heat setting, a second stretching, a second heat setting, a third stretching, a third heat setting, and a fourth stretching performed sequentially. The first and third heat setting are performed at a temperature higher than the glass transition temperature of the nascent fibers made from the transparent nylon chips, while the second heat setting is performed at a temperature lower than the glass transition temperature.

[0036] In an embodiment of the present invention, the cooled fiber is subjected to a drawing and setting process. This process includes at least a first drawing, a first heat setting, a second drawing, a second heat setting, a third drawing, a third heat setting, and a fourth drawing performed sequentially.

[0037] The first stretching step involves applying a stretching force to the cooled fiber at ambient temperature or other suitable preheating temperature to perform preliminary stretching. The main purpose of this step is to induce macroscopic deformation of the fiber, initially break the entanglement of the molecular chains, and guide the molecular chains to begin preliminary orientation along the fiber axis. The magnitude of the stretching force and the stretching ratio are controlled within a range that does not cause fiber breakage or excessive shrinkage.

[0038] The initially drawn fibers are subjected to a first heat-setting temperature. This first heat-setting temperature is higher than the glass transition temperature (Tg) of the transparent nylon, for example, set between 85°C and 95°C. At this temperature, the polymer chain segments acquire significant mobility, which on the one hand effectively releases the instantaneous internal stress generated during the initial drawing, preventing the fibers from shrinking or deforming during subsequent processing or use due to stress concentration; on the other hand, under the action of heat, the initially formed orientation structure is locally fixed and relaxed, forming a relatively stable but not completely locked intermediate state, laying the foundation for subsequent high-ratio orientation. Moreover, although this temperature is higher than Tg, it is still much lower than the rapid crystallization temperature of transparent nylon, thus avoiding the formation of a large number of crystals that are detrimental to transparency during the initial orientation stage.

[0039] After the first heat setting, the fiber undergoes a second drafting. This second drafting can also be performed at near room temperature or under slightly cooled conditions, preferably by applying a greater drafting force than the first drafting to achieve primary orientation. Under this high tension, the molecular chains are further straightened and aligned along the fiber axis, the fiber diameter becomes significantly thinner, and the strength begins to increase substantially. Preferably, the ratio of the first drafting is less than the ratio of the second drafting.

[0040] After the second drafting is completed, the fiber is placed at a second heat-setting temperature. This temperature is lower than the glass transition temperature (Tg) of the transparent nylon, preferably between 25°C and 35°C. At this low temperature, far below Tg, the mobility of the molecular chains is greatly suppressed, almost freezing them. Thus, the highly oriented structure formed by the second drafting is strongly locked, effectively overcoming the strong tendency of transparent nylon to shrink back after tension is removed, ensuring the stability of the fiber size and morphology. Simultaneously, the low-temperature environment strongly inhibits the orderly stacking and crystallization process of the molecular chains, allowing the fiber to maintain an amorphous or extremely low crystallinity state to the maximum extent. Since the amorphous state scatters light much less than the crystalline state, high transparency (low haze) of the monofilament is achieved.

[0041] During the third drafting process, small-scale final drafting or tension adjustments can be made to precisely control the final linear density and fineness uniformity of the monofilament, and to fine-tune the molecular chain orientation. Preferably, the first drafting ratio is smaller than the third drafting ratio.

[0042] Finally, the fibers are subjected to a third heat-setting temperature for final processing. This temperature is higher than the first heat-setting temperature, for example, set between 115°C and 125°C. On the one hand, at a higher temperature, all residual internal stresses in the fiber are fully relaxed, allowing the fiber's dimensional thermal stability to reach its optimal level. On the other hand, this temperature is sufficient to promote the formation of a small number of fine, uniformly distributed, and perfect crystals. These microcrystals, as physical cross-linking points, can significantly improve the fiber's tensile strength, modulus, heat resistance, and fatigue resistance. Furthermore, due to their small size and dispersion, they do not significantly obstruct light transmission, thus maintaining transparency while improving mechanical properties.

[0043] After the third heat setting is completed, the fiber undergoes a fourth drafting process. This fourth drafting is mainly used for final tension adjustment and morphological fine-tuning of the fiber, laying the foundation for subsequent winding.

[0044] After the fourth drafting is completed, the treated monofilaments are wound up. The high-strength, transparent monofilaments, which have undergone multi-stage drafting and heat setting, are continuously and evenly wound onto a spool to form a packaged product that can be used for subsequent weaving or directly. In addition, the wound monofilaments can be used directly for subsequent weaving processes (such as woven or warp knitting), or packaged and sold as commercial yarn.

[0045] It should be noted that the core function of the drafting step in the entire drafting and setting process is to apply mechanical tension to achieve molecular chain orientation and fiber refinement. This step can be performed simultaneously within the corresponding heat setting temperature environment, or it can be completed under conditions independent of the heat setting temperature (such as room temperature rollers). The "first drafting," "second drafting," "third drafting," and "fourth drafting" can each be a single-stage stretching action, or a multi-stage drafting process involving multiple consecutive stretches (such as through multiple pairs of rollers with increasing / decreasing speeds). Similarly, the three heat setting stages can be achieved by three independently temperature-controlled ovens (or hot rollers), or they can be continuously completed within a device with multi-temperature zone programmable temperature control.

[0046] In a preferred embodiment of the present invention, the first heat-setting temperature is 85°C to 95°C, the second heat-setting temperature is 25°C to 35°C, and the third heat-setting temperature is 115°C to 125°C. For example, the first heat-setting temperature can be 85°C, 88°C, 90°C, 92°C, 95°C, etc.; the second heat-setting temperature can be 25°C, 28°C, 30°C, 32°C, 35°C, etc.; and the third heat-setting temperature can be 115°C, 118°C, 120°C, 122°C, 125°C, etc., but is not limited to the listed values; other unlisted values ​​within this range are also applicable. This specific range of values ​​is determined based on a deep understanding of the properties of typical transparent nylon materials and optimization through extensive process experiments. The first heat-setting temperature is slightly higher than the material's Tg to provide sufficient chain segment mobility to relax the initial stretching stress and stabilize the initial orientation, while strictly avoiding entering the rapid crystallization temperature range (typically >100°C). The second heat-setting temperature is significantly lower than Tg, freezing the highly oriented structure formed by high-ratio drawing and maximally suppressing any crystallization processes that might cause light scattering. The third heat-setting temperature is much higher than Tg but lower than the material's melting point or decomposition temperature. At this temperature, all internal stresses can be completely eliminated, achieving dimensional stability, and the formation of microcrystals that enhance mechanical properties can be controlled. The significant temperature difference between this temperature and the second heat-setting temperature allows for the freezing, thawing, and refinement of this structure. Within this window, the haze of the monofilament can be stably controlled at ≤5%, and the breaking strength ≥4.0 cN / dtex.

[0047] In a preferred embodiment of the present invention, the cooling medium is water, and the cooling process is water cooling. Water's high specific heat capacity and high thermal conductivity allow for instantaneous, uniform, and intense cooling of the high-temperature molten fibers just extruded from the spinneret. Specifically, a constant-temperature water bath or a spray water cooling device can be used. For example, the nascent fibers are passed through a constant-temperature water bath with a length of 1.0 m to 2.0 m and a water flow velocity of 0.5 m / s to 1.5 m / s. Water cooling minimizes the residence time of the molten fibers in the high-temperature zone, allowing them to pass through the crystallization temperature zone at a high cooling rate, thereby freezing the molecular chain arrangement in a disordered or low-order amorphous state, resulting in nascent fibers with low haze (high transparency). Compared to gas or solid cooling methods, water cooling is more efficient, resulting in a more uniform fiber structure and superior transparency.

[0048] The cooling process involves passing the nascent fibers sequentially through a first cooling zone and a second cooling zone, with the second cooling temperature higher than the first. Specifically, the first cooling zone (e.g., a cold water tank) provides powerful quenching, typically controlled at 35°C to 45°C (e.g., 40°C), its core function being to rapidly solidify the fiber morphology and lock in the amorphous structure. Subsequently, the fibers immediately enter a significantly warmer second cooling zone (e.g., a hot water tank), for example, the temperature of the second cooling zone is configured to be higher than the temperature of the first heat setting, thus typically controlled at 95°C to 100°C (e.g., 98°C). This rapid cooling followed by warming ensures the formation of the amorphous state through the first stage of cooling; the second stage (hot water zone) is not simply heating, but rather a controlled partial warming of the fibers from a deeply frozen state. This helps release the surface stress caused by rapid cooling, making the overall temperature distribution of the fiber more uniform before entering the subsequent drawing stage, and the molecular chains are in a ready state with a certain potential for activity, thereby significantly improving the subsequent processing performance of the fiber and reducing the risk of fiber breakage due to cold brittleness in the early stage of drawing.

[0049] A second aspect of the present invention provides a method for preparing a high-strength transparent monofilament, comprising the following steps: Step 1: Provide dried, clear nylon slices; Step 2: Melt-blend the transparent nylon chips with functional additives, cool, granulate and dry to obtain modified chips; Step 3: Melt and extrude the modified chips to form nascent fibers; Step 4: Contact the nascent fibers with a cooling medium to cool them and obtain cooled fibers; Step 5: Stretch and set the cooled fiber, the stretching and setting including at least one stretching and at least two heat setting operations performed sequentially, the two heat setting operations being performed successively at glass transition temperatures higher and lower than the nascent fiber; Step 6: Rewind; The stretching and setting process includes at least a first stretching, a first heat setting, a second stretching, a second heat setting, a third stretching, a third heat setting, and a fourth stretching performed sequentially; the first heat setting and the third heat setting are performed at a temperature higher than the glass transition temperature of the nascent fibers made from the transparent nylon chips, and the second heat setting is performed at a temperature lower than the glass transition temperature.

[0050] In a preferred embodiment of the second aspect of the present invention, the method further includes a step of melt-blending and modifying transparent nylon chips with functional auxiliaries before spinning.

[0051] In practice, dried transparent nylon chips and functional additives can be fed together into a twin-screw extruder and melt-blended at a temperature of 120°C to 150°C. The resulting chips are then cooled in a water bath, pelletized, and dried again to obtain modified chips. By uniformly dispersing the functional additives into the polymer matrix at the initial stage of material processing, a long-lasting protective system is pre-built within the material to resist subsequent processing (such as high-temperature extrusion and heat setting) and unavoidable thermal oxidation and ultraviolet radiation during use. This significantly delays yellowing caused by aging, maintains the long-term clear and transparent appearance of the monofilaments, and improves the product's weather resistance and service life.

[0052] In a preferred embodiment of the present invention, the anti-yellowing additive comprises a composite system of a primary antioxidant, a secondary antioxidant, and a UV absorber. Preferably, the primary antioxidant is a phenol-free hydroxylamine antioxidant (such as Revonox 420 from BASF), and its addition amount is 0.3% to 0.5% of the mass of the transparent nylon chips, for example, 0.3%, 0.4%, 0.5%, or any value therein; the secondary antioxidant is a thioester antioxidant (such as DLTP), and its addition amount is 0.1% to 0.2%, for example, 0.1%, 0.15%, 0.2%, or any value therein; the UV absorber is a benzotriazole UV absorber (such as Tinuvin 326 from BASF), and its addition amount is 0.2% to 0.4%, for example, 0.2%, 0.3%, 0.4%, or any value therein. The primary antioxidant blocks the thermal oxidation chain reaction by capturing alkyl radicals (R·) and alkoxy radicals (RO·); the secondary antioxidant decomposes the generated hydroperoxides (ROOH) into stable products, preventing them from decomposing and generating new free radicals; the ultraviolet absorber absorbs ultraviolet light in the 290-400nm range and converts it into harmless heat energy, preventing photo-induced degradation. Thus, through different pathways, the yellowing of transparent nylon is inhibited synergistically, thereby achieving excellent anti-yellowing performance.

[0053] A third aspect of the present invention provides a high-strength transparent monofilament, which is prepared by the method described in the first aspect or the second aspect of the present invention.

[0054] In a preferred embodiment of the present invention, the high-strength transparent monofilament has a haze of ≤5%, a breaking strength of ≥4.0cN / dtex, and a breaking elongation of 25%-35%.

[0055] A fourth aspect of the present invention provides a fabric comprising the high-strength transparent monofilament described in the third aspect of the present invention.

[0056] In a preferred embodiment of the present invention, the fabric is woven using a machine weaving process. Specifically, a shuttle weaving process is employed using a multi-arm loom, with the high-strength transparent monofilament provided in the third aspect of the present invention used as the warp and / or weft yarns. The preferred fabric structure is a leno weave, for example, woven with a single-layer transparent diamond-shaped pattern through specific heddle-threading and bend-down techniques. This leno weave can form a stable twisted structure, providing basic mechanical properties while the tiny perforations between the weave points achieve breathability. While ensuring high transparency and aesthetic appeal and necessary strength, it effectively improves airflow in application areas such as shoe uppers, enhancing wearing comfort.

[0057] In another preferred embodiment of the invention, the fabric is woven using a knitting process. Specifically, a warp knitting jacquard machine is used, employing the high-strength transparent monofilament provided in the third aspect of the invention as the comb yarn. The preferred weave structure is a warp twill weave; for example, the front comb (L1) uses a padding yarn number of 4-5 / 1-0 / / , and the back comb (L2) uses a padding yarn number of 1-0 / 0-1 / / . The warp twill weave allows the long extensions of the front comb yarns to be arranged tightly and straight on the fabric surface. This allows a large amount of incident light to undergo specular reflection on the nearly continuous plane formed by the monofilaments, thereby greatly enhancing the fabric's luster and transparency. Simultaneously, the knitted structure itself imparts excellent elasticity and flexibility to the fabric.

[0058] A fifth aspect of the present invention provides a footwear article having an upper and a sole structure fixed to the upper, the upper including a woven component comprising at least one monofilament region formed of a high-strength transparent monofilament of the third aspect of the present invention, the at least one monofilament region having a shape.

[0059] The term "monofilament area" is used to indicate a portion of the shoe upper formed by the high-strength transparent monofilament woven from the third aspect of the present invention.

[0060] The monofilament region can have various shapes, such as elongated, trapezoidal, or triangular, and its specific shape can be defined by the adjacent edge or boundary part (such as the instep boundary or sole boundary). These regions can be selectively located on the outer side, inner side, forefoot area, or heel area of ​​the shoe upper, for example, forming an outer monofilament group and an inner monofilament group to meet the aesthetic and functional needs of specific areas.

[0061] For example, the monofilament area is preferably an integral part of the woven component, and is seamlessly integrated with other areas of the shoe upper (usually multifilament yarn woven areas) in an "integrated woven structure" manner, thereby forming an integrated woven component, reducing the seams, stress concentration and manufacturing waste caused by the splicing of multiple pieces of traditional shoe uppers.

[0062] The following describes embodiments of the present invention. These embodiments are exemplary and are only used to explain the present invention, and should not be construed as limiting the invention. Where techniques or conditions are not specified in the embodiments, they are performed according to the techniques or conditions described in the literature in the art or according to the product instructions. Reagents or instruments used, unless otherwise specified, are all commercially available conventional products.

[0063] Example 1 This embodiment provides a high-strength transparent monofilament, comprising the following preparation steps: Step 1: Material preparation. Select the following raw materials: transparent nylon chips. The transparent nylon used in this embodiment is selected from aliphatic transparent nylon, specifically Arkema G820 Rnew. Step 2: Drying. Dry the transparent nylon slices in hot air at 80°C for 6 hours to remove moisture and control the moisture content to 0.2%. Step 3: Extrusion. The dried transparent nylon chips are fed into a twin-screw extruder, heated and melted, and then extruded. The transparent nylon passes through the extrusion nozzle, the spinneret has a diameter of 0.7 mm, and the extrusion temperatures of the monofilaments in different zones of the twin-screw extruder are 230℃, 245℃, 255℃, 255℃, and 250℃; the motor speed is 40 r / min, and the melt pressure is 18 MPa. Step 4: Cooling. After the monofilament is extruded, it passes through a constant temperature water cooling module with a water flow of 0.8 m / s and a cooling length of 1.5 m. It first passes through a cold water tank at a temperature of 40°C and then through a hot water tank at a temperature of 98°C. Step 5: Drawing and Setting. The monofilament is drawn from the hot water tank through the drawing rollers, and then set once in the stretching oven. A total of four drawing cycles are performed, followed by three oven setting cycles. The drawing roller speeds are 32 m / min in zone 1, 120 m / min in zone 2, 115 m / min in zone 3, and 115 m / min in zone 4. The temperature in zone 1 of the stretching oven is 90℃, in zone 2 it is 30℃, and in zone 3 it is 120℃. Step 6: Winding up. The prepared modified transparent nylon monofilament is wound up using a winding device to obtain modified high-strength transparent monofilament.

[0064] Example 2 The difference between this embodiment and Embodiment 1 is that the raw material transparent nylon chips used are selected from aliphatic transparent nylon 66, specifically DuPont 103FHS NCO10.

[0065] Example 3 The difference between this embodiment and Embodiment 1 is that the raw material, transparent nylon chips, is selected from semi-aromatic nylon MXD6, specifically Mitsubishi MXD6 S6001.

[0066] Example 4 The difference between this embodiment and embodiment 1 is that step 4 only involves cooling via a cold water tank.

[0067] Example 5 This embodiment provides a high-strength transparent monofilament, comprising the following preparation steps: Step 1: Material preparation. Select the following raw materials: transparent nylon chips. The transparent nylon used in this embodiment is selected from aliphatic transparent nylon, specifically Arkema G820 Rnew. Step 2: Modification. The dried transparent nylon chips are placed in a twin-screw extruder for melting at a melting temperature of 220°C. When the chips are melted into a fluid state, antioxidant Revonox 420 (primary antioxidant) 0.4%, DLTP (secondary antioxidant) 0.2%, and UV absorber Tinuvin 326 0.3% are added. Step 3: Cooling and pelletizing. The modified nylon is placed in a cold water bath for cooling and pelletizing to obtain modified nylon chips. The temperature of the cold water bath is 8℃. Step 4: Drying. The modified nylon slices are dried in hot air at 80°C for 6 hours to remove moisture and control the moisture content to 0.2%. Step 5: Extrusion. The dried modified nylon chips are fed into a twin-screw extruder, heated and melted, and then extruded. The modified nylon passes through the extrusion nozzle, the spinneret has a diameter of 0.7 mm, and the extrusion temperatures of the monofilaments in different zones of the twin-screw extruder are 230℃, 245℃, 255℃, 255℃, and 250℃; the motor speed is 40 r / min, and the melt pressure is 18 MPa. Step 6: Cooling. After the monofilament is extruded, it passes through a constant temperature water cooling module with a water flow rate of 0.8 / s and a cooling length of 1.5m. It first passes through a cold water tank at a temperature of 40℃, and then through a hot water tank at a temperature of 98℃. Step 7: Drawing and Setting. The monofilament is drawn from the hot water tank through the drawing rollers, and then set once in the stretching oven. A total of four drawing cycles are performed, followed by three oven setting cycles. The drawing roller speeds are 32 m / min in zone 1, 120 m / min in zone 2, 115 m / min in zone 3, and 115 m / min in zone 4. The temperature in zone 1 of the stretching oven is 90℃, in zone 2 it is 30℃, and in zone 3 it is 120℃. Step 8: Winding up. The prepared modified transparent nylon monofilament is wound up using a winding device to obtain modified high-strength transparent monofilament.

[0068] Example 6 The difference between this embodiment and embodiment 5 is that the stretching oven zone 1 is 86°C, the stretching oven zone 2 is 28°C, and the stretching oven zone 3 is 118°C. Example 7 The difference between this embodiment and embodiment 5 is that the stretching oven zone 1 is 93°C, the stretching oven zone 2 is 32°C, and the stretching oven zone 3 is 123°C.

[0069] Comparative Example 1 This comparative example provides a transparent monofilament, comprising the following preparation steps: Step 1: Prepare materials. Select the following raw materials: transparent nylon chips. The transparent nylon used in this comparative example is aliphatic transparent nylon, specifically Arkema G820 Rnew. Step 2: Drying. Dry the transparent nylon slices in hot air at 60°C for 6 hours to remove moisture and control the moisture content to 0.5%. Step 3: Extrusion. The dried transparent nylon chips are fed into a twin-screw extruder, heated and melted, and then extruded. The transparent nylon passes through the extrusion nozzle, the spinneret has a diameter of 0.7 mm, and the extrusion temperatures of the monofilaments in different zones of the twin-screw extruder are 230℃, 245℃, 255℃, 255℃, and 250℃; the motor speed is 40 r / min, and the melt pressure is 18 MPa. Step 4: Cooling. After the monofilament is extruded, it passes through a constant temperature water cooling module with a water flow of 0.8 m / s and a cooling length of 1.5 m. It first passes through a cold water tank at a temperature of 40°C and then through a hot water tank at a temperature of 98°C. Step 5: Drawing and Setting. The monofilament is drawn from the hot water tank through the drawing rollers, and then set once in the stretching oven. A total of four drawing cycles are performed, followed by three oven setting cycles. The drawing roller speeds are 32 m / min in zone 1, 120 m / min in zone 2, 115 m / min in zone 3, and 115 m / min in zone 4. The temperatures in the stretching ovens are 90℃ in zone 1, 120℃ in zone 2, and 120℃ in zone 3. Step 6: Winding up. The prepared modified transparent nylon monofilament is wound up using a winding device to obtain modified high-strength transparent monofilament.

[0070] Comparative Example 2 This comparative example provides a transparent monofilament, comprising the following preparation steps: Step 1: Material preparation. Select the following raw materials: transparent TPU material. The transparent TPU material used in this comparative example is Wanhua TPU Wanthane WHT-158. Step 2: Modification. The dried chips are placed in a twin-screw extruder for melting at a melting temperature of 200℃. When the chips are melted into a fluid state, antioxidant Revonox 420 (primary antioxidant) 0.4%, DLTP (secondary antioxidant) 0.2%, and UV absorber Tinuvin 3260 0.3% are added. Step 3: Cooling and pelletizing. The modified TPU is placed in a cold water bath for cooling and pelletizing to obtain modified TPU slices. The temperature of the cold water bath is 8℃. Step 4: Drying. Dry the TPU slices in hot air at 80°C for 6 hours to remove moisture and control the moisture content to 0.2%. Step 5: Extrusion. The dried TPU modified chips are fed into a twin-screw extruder, heated and melted, and then extruded. The modified nylon passes through the extrusion nozzle. The spinneret has a diameter of 0.7 mm. The extrusion temperatures of the monofilaments in different zones of the twin-screw extruder are 230℃, 245℃, 255℃, 255℃, and 250℃. The motor speed is 40 r / min, and the melt pressure is 18 MPa. Step 6: Cooling. After the monofilament is extruded, it passes through a constant temperature water cooling module with a water flow of 0.8 m / s and a cooling length of 1.5 m. It first passes through a cold water tank at a temperature of 35°C and then through a hot water tank at a temperature of 80°C. Step 7: Drawing and setting. The monofilament is drawn from the hot water tank through the drawing rollers. After one drawing, it is set once in the stretching oven. A total of four drawing cycles are performed, followed by three oven setting cycles. The speed of the drawing rollers in the first drawing zone is 32 m / min, the speed of the drawing rollers in the second drawing zone is 120 m / min, the speed of the drawing rollers in the third drawing zone is 115 m / min, and the speed of the drawing rollers in the fourth drawing zone is 115 m / min. The temperature of the stretching oven is 85℃ in the first zone, 25℃ in the second zone, and 100℃ in the third zone. Step 8: Winding up. The prepared modified transparent TPU monofilament is wound up using a winding device to obtain modified high-strength transparent TPU monofilament.

[0071] Comparative Example 3 This comparative example provides a transparent monofilament, comprising the following preparation steps: Step 1: Material preparation. Select the following raw materials: transparent PET chips. The transparent PET chips used in this comparative example are Baihong 07E01. Step 2: Drying. Dry the transparent PET slices in hot air at 80°C for 6 hours to remove moisture and control the moisture content to 0.2%. Step 3: Extrusion. The dried PET chips are fed into a twin-screw extruder, heated and melted, and then extruded. The PET passes through the extrusion nozzle, the spinneret has a diameter of 0.7 mm, and the extrusion temperatures of the monofilaments in each zone of the twin-screw extruder are 260℃, 265℃, 270℃, 275℃, and 275℃; the motor speed is 40 r / min, and the melt pressure is 18 MPa. Step 4: Cooling. After the monofilament is extruded, it passes through a constant temperature water cooling module with a water flow of 0.8 m / s and a cooling length of 1.5 m. It first passes through a cold water tank at a temperature of 40°C and then through a hot water tank at a temperature of 98°C. Step 5: Drawing and Setting. The monofilament is drawn from the hot water tank through the drawing rollers, and then set once in the stretching oven. A total of four drawing cycles are performed, followed by three oven setting cycles. The drawing roller speeds are 32 m / min in zone 1, 120 m / min in zone 2, 115 m / min in zone 3, and 115 m / min in zone 4. The temperature in zone 1 of the stretching oven is 90℃, in zone 2 it is 30℃, and in zone 3 it is 120℃. Step 6: Winding up. The prepared modified transparent PET monofilament is wound up using a winding device to obtain transparent PET monofilament.

[0072] Comparative Example 4 This comparative example provides a transparent monofilament, comprising the following preparation steps: Step 1: Prepare materials. Select the following raw materials: transparent nylon chips. The transparent nylon used in this comparative example is aliphatic transparent nylon, specifically Arkema G820 Rnew. Step 2: Modification. The dried chips are placed in a twin-screw extruder for melting at a melting temperature of 220℃. When the chips are melted into a fluid state, antioxidant Revonox 420 (primary antioxidant) 0.4%, DLTP (secondary antioxidant) 0.2%, and UV absorber Tinuvin 326 0.3% are added. Step 3: Cooling and pelletizing. The modified nylon is placed in a cold water bath for cooling and pelletizing to obtain modified nylon chips. The temperature of the cold water bath is 8℃. Step 4: Drying. The modified nylon slices are dried in hot air at 80°C for 6 hours to remove moisture and control the moisture content to 0.2%. Step 5: Extrusion. The dried modified nylon chips are fed into a twin-screw extruder, heated and melted, and then extruded. The modified nylon passes through the extrusion nozzle, the spinneret has a diameter of 0.7 mm, and the extrusion temperatures of the monofilaments in different zones of the twin-screw extruder are 230℃, 245℃, 255℃, 255℃, and 250℃; the motor speed is 40 r / min, and the melt pressure is 18 MPa. Step 6: Cooling. After the monofilament is extruded, it passes through a constant temperature water cooling module with a water flow of 0.8 m / s and a cooling length of 1.5 m. It first passes through a cold water tank at a temperature of 40°C and then through a hot water tank at a temperature of 98°C. Step 7: Drawing and Setting. The monofilament is drawn from the hot water tank through the drawing rollers, and then set once in the stretching oven. A total of four drawing cycles are performed, followed by three oven setting cycles. The drawing roller speeds are 32 m / min in zone 1, 120 m / min in zone 2, 115 m / min in zone 3, and 115 m / min in zone 4. The temperatures in the stretching ovens are 90℃ in zone 1, 120℃ in zone 2, and 120℃ in zone 3. Step 8: Winding up. The prepared modified transparent nylon monofilament is wound up using a winding device to obtain the modified transparent monofilament.

[0073] Test case The monofilaments prepared in the above embodiments and comparative examples were subjected to the following physical and chemical tests: (1) The testing standards for fracture strength and elongation at break are: GB / T 3923.1-2013; (2) The standard for phenol yellowing test is GB / T 29778-2013; (3) The test standard for bulb-type yellowing resistance is: HGT 3689-2014; (4) The test standards for transmittance and haze are ISO 13468-1 and ASTM D1003.

[0074] The test results for each embodiment and comparative example are shown in the table below: Table 1. Summary of test results for each embodiment.

[0075] Table 2. Summary of Test Results for Each Comparative Example

[0076] Compared to Comparative Example 1, Example 1 employed a heat-setting temperature sequence of "increase—decrease—increase again" (90℃-30℃-120℃), successfully achieving the control of initial molecular chain orientation, low-temperature freezing, and high-temperature stabilization. The results showed that Example 1 exhibited significantly improved fracture strength, significantly improved light transmittance, and significantly reduced haze.

[0077] Compared to Example 4 (which only underwent single-stage cooling with cold water), Example 1 employed a two-stage cooling process, first using cold water and then hot water. First, the fiber morphology was rapidly quenched and solidified using cold water (40°C) to lock in the amorphous structure, and then the fiber was warmed back to release surface stress and improve its subsequent processing performance using hot water (98°C). The results showed that Example 1 exhibited significantly improved breaking strength, increased light transmittance, and significantly reduced haze.

[0078] Compared to Example 1, Example 5 added anti-yellowing additives (primary antioxidant, secondary antioxidant, and UV absorber) to the raw materials. The results showed that the breaking strength, light transmittance, and haze performance of both were similar, but the phenolic yellowing and bulb-type yellowing resistance of Example 5 improved from level 3 to level 4. This indicates that the anti-yellowing additive significantly improved the long-term weather resistance and anti-yellowing ability of the product without impairing the mechanical and optical properties of the monofilament.

[0079] Comparative Example 2 used transparent TPU material, Comparative Example 3 used transparent PET material, and Comparative Example 4 used the same transparent nylon raw material as Example 5 but lacked the low-temperature heat setting stage. The results showed that the strength and transparency of Comparative Example 2 were both inferior to the transparent nylon example using the same process. Comparative Example 3 had the highest haze and lowest light transmittance due to the high crystallinity of its material, while Comparative Example 4's performance was far inferior to Example 5 due to the lack of a low-temperature stage. This indicates that the "heat setting process of the present invention—first heating—then cooling—then heating" has optimal compatibility with transparent nylon material, and can synergistically achieve high strength and high transparency.

[0080] Application Example 1 This application example provides a warp-knitted fabric, including the following steps: Step 1: Prepare materials. Select the following raw materials: transparent nylon chips. The transparent nylon used in this application example is selected from aliphatic transparent nylon, specifically Arkema G820 Rnew. Step 2: Modification. The dried chips are placed in a twin-screw extruder for melting at a melting temperature of 220°C. When the chips are melted into a fluid state, antioxidant Revonox 420 (primary antioxidant) 0.4%, DLTP (secondary antioxidant) 0.2%, and UV absorber Tinuvin 326 0.3% are added.

[0081] Step 3: Cooling and pelletizing. The modified nylon is placed in a cold water bath for cooling and pelletizing to obtain modified nylon chips. The temperature of the cold water bath is 8℃. Step 4: Drying. Dry the nylon slices in hot air at 80°C for 6 hours to remove moisture and control the moisture content to 0.2%. Step 5: Extrusion. The dried modified nylon chips are fed into a twin-screw extruder, heated and melted, and then extruded. The modified nylon passes through the extrusion nozzle. The spinneret has a diameter of 0.7 mm. The extrusion temperatures of the monofilaments in each zone of the twin-screw extruder are 230℃, 245℃, 255℃, 255℃, and 250℃. The motor speed is 40 r / min, and the melt pressure is 18 MPa.

[0082] Step 6: Cooling. After the monofilament is extruded, it passes through a constant temperature water cooling module with a water flow of 0.8 m / s and a cooling length of 1.5 m. It first passes through a cold water tank at a temperature of 40°C and then through a hot water tank at a temperature of 98°C.

[0083] Step 7: Drawing and Setting. The monofilament is drawn from the hot water tank through the drawing rollers, and then set once in the stretching oven. A total of four drawing cycles are performed, followed by three oven setting cycles. The drawing roller speeds are 32 m / min in zone 1, 120 m / min in zone 2, 115 m / min in zone 3, and 115 m / min in zone 4. The stretching oven temperatures are 90℃ in zone 1, 30℃ in zone 2, and 120℃ in zone 3. Step 8: Winding up. The prepared modified transparent nylon monofilament is wound up using a winding device to obtain modified high-strength transparent nylon monofilament.

[0084] Step 9: Reading the sample: Import the warp knitting pattern design into the warp knitting jacquard machine and read the pattern code.

[0085] Step 10: Yarn threading. According to the pattern, thread the high-strength transparent monofilament through the corresponding guide needles, Jacquard needles, and sinkers on the warp knitting machine to ensure that the threading sequence is accurate.

[0086] Step 11: Knitting the pattern. The knitting needles knit according to the pattern. The front needle bed L1 knits the right-side loops, and the back needle bed L2 knits the wrong-side loops. The monofilaments follow the guide bar according to the yarn guide number. The yarn guide number for L1 is 4-5 / 1-0 / / , and the yarn guide number for L2 is 1-0 / 0-1 / / . The knitting density is 12C / cm.

[0087] Step 12: Wash with water at 45°C for 20 minutes. Use a bath ratio (fabric weight to water volume) of 1:15. After multiple rinses, spin dry at low speed (800 rpm) for 5 minutes.

[0088] Step 13: Setting the heat setter. Set the heat setter to 130℃ and the speed to 25m / min. The fabric enters the heat setter and passes through the preheating zone (120℃), the constant temperature zone (130℃, 135℃, 140℃), and the cooling zone (18℃). The constant temperature zone is held for 30 seconds to ensure the stability of the monofilament structure. The cooling zone uses cold air to cool down to room temperature to avoid secondary deformation caused by residual heat.

[0089] Application Example 2 This application example provides a woven fabric, including the following steps: Step 1: Prepare materials. Select the following raw materials: transparent nylon chips. The transparent nylon used in this application example is selected from aliphatic transparent nylon, specifically Arkema G820 Rnew. Step 2: Modification. The dried chips are placed in a twin-screw extruder for melting at a melting temperature of 220°C. When the chips are melted into a fluid state, antioxidant Revonox 420 (primary antioxidant) 0.4%, DLTP (secondary antioxidant) 0.2%, and UV absorber Tinuvin 326 0.3% are added.

[0090] Step 3: Cooling and pelletizing. The modified nylon is placed in a cold water bath for cooling and pelletizing to obtain modified nylon chips. The temperature of the cold water bath is 8℃. Step 4: Drying. Dry the nylon slices in hot air at 80°C for 6 hours to remove moisture and control the moisture content to 0.2%. Step 5: Extrusion. The dried modified nylon chips are fed into a twin-screw extruder, heated and melted, and then extruded. The modified nylon passes through the extrusion nozzle. The spinneret has a diameter of 0.7 mm. The extrusion temperatures of the monofilaments in each zone of the twin-screw extruder are 230℃, 245℃, 255℃, 255℃, and 250℃. The motor speed is 40 r / min, and the melt pressure is 18 MPa.

[0091] Step 6: Cooling. After the monofilament is extruded, it passes through a constant temperature water cooling module with a water flow of 0.8 m / s and a cooling length of 1.5 m. It first passes through a cold water tank at a temperature of 40°C and then through a hot water tank at a temperature of 98°C.

[0092] Step 7: Drawing and Setting. The monofilament is drawn from the hot water tank through the drawing rollers, and then set once in the stretching oven. A total of four drawing cycles are performed, followed by three oven setting cycles. The drawing roller speeds are 32 m / min in zone 1, 120 m / min in zone 2, 115 m / min in zone 3, and 115 m / min in zone 4. The stretching oven temperatures are 90℃ in zone 1, 30℃ in zone 2, and 120℃ in zone 3.

[0093] Step 8: Winding up. The prepared modified transparent nylon monofilament is wound up using a winding device to obtain modified high-strength transparent monofilament.

[0094] Step 9: Warping. The high-strength, transparent monofilament warp yarns are drawn from the bobbins on the bobbin holder, ensuring each warp yarn passes independently through the tensioner to avoid tangling or crossing, and ensuring a uniform yarn threading sequence and arrangement. At the end, the warp yarns are gathered and fixed onto the selvage or core of the warp beam. The warping machine is then started, and the warp yarns are wound onto the warp beam at a constant speed under the control of the tensioner.

[0095] Step 10: Thread the warp. According to the process design requirements, use a reed number of 18.3 and 16 heddle pieces to thread the warp yarns through the heddle holes and reed teeth in a regular pattern, and then insert open-ended warp stops on the warp yarns.

[0096] Step 11: Read the pattern. Import the weave design diagram into the woven multi-arm loom and read the weave diagram to form the corresponding pattern diagram.

[0097] Step 12: Weaving pattern. The weft density of the finished product is controlled at 26 threads / 10cm on a shuttle loom according to the pattern diagram.

[0098] Step 13: Wash with water at 45°C for 20 minutes. Use a bath ratio (fabric weight to water volume) of 1:15. After multiple rinses, spin dry at low speed (800 rpm) for 5 minutes.

[0099] Step 14: Setting. Set the heat setter to 130℃ and the speed to 25m / min. The fabric enters the heat setter and passes through the preheating zone (120℃), constant temperature zone (130℃, 135℃, 140℃), and cooling zone (18℃). The constant temperature zone is held for 30 seconds to ensure the stability of the monofilament structure. The cooling zone uses cold air to cool the fabric to room temperature to avoid secondary deformation caused by residual heat.

[0100] Application Example 3 Application Example 3 uses the same warp knitting process as Application Example 1 for weaving and washing and shaping, the only difference being that the yarn used is replaced with transparent PET monofilament made in Comparative Example 3.

[0101] Application Example 4 Application Example 3 uses the same weaving process as Application Example 2 for weaving and washing and shaping, the only difference being that the yarn used is replaced with transparent PET monofilament made in Comparative Example 3.

[0102] High-strength transparent monofilaments were prepared according to the method of Example 1, and woven using different processes according to Application Examples 1 and 2 to produce fabrics of the same size. These fabrics were then compared with Application Examples 3 and 4 to perform the following physical property tests: (1) The product property standard (LX-P-006) for the stress-bearing parts of the running shoe upper is: QP-LN-P006; (2) The test standards for transmittance and haze are: ISO 2471 and ASTM D3575.

[0103] The test results for each application example are shown in the table below: Table 2 Summary of test results for each application example

[0104] Compared to Application Example 3 (using ordinary PET monofilament), Application Example 1 used the high-strength transparent nylon monofilament of the present invention, woven using the same warp knitting process. The results showed that Application Example 1 exhibited significantly improved burst strength, significantly improved light transmittance, and significantly reduced haze. This indicates that the warp-knitted fabric made from the monofilament of the present invention is comprehensively superior to ordinary PET monofilament fabric in both mechanical and optical properties.

[0105] Compared to Application Example 4 (using ordinary PET monofilament), Application Example 2 used the high-strength transparent nylon monofilament of the present invention, woven using the same weaving process. The results showed that Application Example 2 exhibited significantly improved burst strength, significantly improved light transmittance, and significantly reduced haze. This indicates that the woven fabric made from the monofilament of the present invention is also comprehensively superior to ordinary PET monofilament fabric in both mechanical and optical properties.

[0106] Furthermore, those skilled in the art should understand that although many problems exist in the prior art, each embodiment or technical solution of the present invention can be improved in only one or a few aspects, without necessarily solving all the technical problems listed in the prior art or the background art simultaneously. Those skilled in the art should understand that any content not mentioned in a claim should not be construed as a limitation on that claim.

[0107] Although this document frequently uses terms such as transparent nylon, melt extrusion, nascent fiber, cooling medium, cooling fiber, stretching and setting, functional additives, primary antioxidant, secondary antioxidant, and ultraviolet absorber, the possibility of using other terms is not excluded. These terms are used merely for the convenience of describing and explaining the essence of the invention; interpreting them as any additional limitation would contradict the spirit of the invention. The terms "first," "second," etc. (if present) in the description and claims of the embodiments of the invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence.

[0108] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for preparing a high-strength transparent monofilament, Its features are, Includes the following steps: Dry, clear nylon slices are provided; The dried transparent nylon chips are melt-extruded to form nascent fibers; The nascent fibers are brought into contact with a cooling medium to cool them, thereby obtaining cooled fibers. The cooled fiber is drawn and shaped, the drawing and shaping comprising at least one drawing and at least two heat-setting processes performed sequentially, the two heat-setting processes being performed successively at glass transition temperatures higher and lower than those of the nascent fiber.

2. The preparation method according to claim 1, characterized in that, The transparent nylon is selected from one or more of aliphatic transparent nylon, alicyclic transparent nylon, or semi-aromatic transparent nylon.

3. The preparation method according to claim 1, characterized in that, The stretching and setting process includes a first stretching, a first heat setting, a second stretching, a second heat setting, a third stretching, a third heat setting, and a fourth stretching, performed sequentially.

4. The preparation method according to claim 3, characterized in that, The first and third heat setting are performed at a temperature higher than the glass transition temperature of the nascent fibers made from the transparent nylon chips, while the second heat setting is performed at a temperature lower than the glass transition temperature.

5. The preparation method according to claim 4, characterized in that, The first heat setting temperature is 85°C to 95°C, the second heat setting temperature is 25°C to 35°C, and the third heat setting temperature is 115°C to 125°C.

6. The preparation method according to claim 1, characterized in that, The cooling medium is water, and the cooling process is water cooling.

7. The preparation method according to claim 6, characterized in that, The cooling process includes passing the nascent fibers sequentially through a first cooling zone and a second cooling zone, wherein the first cooling zone provides a first cooling temperature and the second cooling zone provides a second cooling temperature, and the second cooling temperature is higher than the first cooling temperature.

8. The preparation method according to claim 3 or 7, characterized in that, The temperature of the second cooling zone is configured to be higher than the temperature of the first heat setting.

9. A method for preparing a high-strength transparent monofilament, characterized in that: Includes the following steps: Dry, clear nylon slices are provided; The transparent nylon chips are melt-blended with functional additives, cooled, granulated, and dried to obtain modified chips; The modified chips are melt-extruded to form nascent fibers; The nascent fibers are brought into contact with a cooling medium to cool them, thereby obtaining cooled fibers. The cooled fiber is drawn and shaped, the drawing and shaping comprising at least one drawing and at least two heat-setting processes performed sequentially, the two heat-setting processes being performed successively at glass transition temperatures higher and lower than those of the nascent fiber.

10. The preparation method according to claim 9, characterized in that, The functional additives include one or more of primary antioxidants, secondary antioxidants, and ultraviolet absorbers.

11. The preparation method according to claim 10, characterized in that, The primary antioxidant is a phenol-free hydroxylamine antioxidant, and its addition amount accounts for 0.3%-0.5% of the mass of the modified slices; and / or The auxiliary antioxidant is a thioester antioxidant, and its addition amount accounts for 0.1%-0.2% of the mass of the modified slices; and / or The ultraviolet absorber is a benzotriazole ultraviolet absorber, and its addition amount accounts for 0.2%-0.4% of the mass of the modified slices.

12. A high-strength transparent monofilament, characterized in that, Prepared by the method according to any one of claims 1 to 11.

13. The high-strength transparent monofilament according to claim 12, characterized in that, The high-strength transparent monofilament has a haze of ≤5%, a breaking strength of ≥4.0cN / dtex, and a breaking elongation of 25%-35%.

14. A fabric, characterized in that, It includes the high-strength transparent monofilament as described in claim 12 or 13.

15. A type of footwear, characterized in that, It has an upper and a sole structure fixed to the upper, the upper including a woven component comprising at least one monofilament region made of a high-strength transparent monofilament as described in claim 12 or 13, the at least one monofilament region having a shape.

Images