Highly breathable anti-ultraviolet fabric and preparation method thereof

Abstract

The application discloses a kind of high air-permeable anti-ultraviolet fabric and preparation method thereof, it is related to textile technical field, and its technical solution main point is, including: step S1, titanium dioxide and nylon are blended melt, and anti-ultraviolet nylon filament with flat cross-section structure is prepared;Step S2, segmented twist warp yarn with twisted dense section and untwisted fluffy section alternately distributed is processed;Step S3, preparation elastic core-spun weft yarn;Step S4, carry out differentiating tension weaving, control second weft yarn tension lower than first weft yarn, induce cloth surface to form three-dimensional micro-crease structure;Step S5, heat setting treatment.The application realizes durable anti-ultraviolet by the physical covering of flat wire, avoids coating to block micropore;Original air-permeable channel is constructed using untwisted fluffy section of warp yarn, realizes physical air-permeable under high shielding;Three-dimensional micro-crease structure reduces skin contact area, solves wet sticking problem, and is endowed with fabric breathability function of dynamic adjustment of air-permeable aperture with movement stretching.

Description

Technical Field

[0001] This invention relates to the field of textile technology, and in particular to a highly breathable and UV-resistant fabric and its preparation method. Background Technology

[0002] Sports sun protection clothing fabrics have multiple functions. For example, they not only need to provide long-lasting UV protection, but also need to have excellent breathability, sweat-wicking and quick-drying properties, as well as good elasticity and fit.

[0003] Currently, sun-protective fabrics achieve high UPF values ​​primarily through two technological approaches: one is to increase the warp and weft density of the fabric to physically block ultraviolet rays; the other is to use thick anti-UV coatings or finishing agents. However, the high-density weave structure inevitably leads to a significant reduction in fabric porosity, forming a sealed film that prevents heat generated during movement from dissipating. Furthermore, coating processes not only easily clog the micropores between fibers, further worsening breathability, but also tend to peel off easily after frequent washing, causing a rapid decline in sun protection function. Existing technologies struggle to create effective breathable channels within the fabric without using coatings while maintaining high shielding efficiency.

[0004] Traditional woven fabrics typically have a fixed structure. When the body is in a state of high heat and sweating, the fabric's breathable pores cannot adjust and expand accordingly. This static structure cannot meet the heat dissipation needs during peak exercise, causing heat to accumulate on the skin and creating a stuffy feeling. Furthermore, after heavy sweating, the fabric clings tightly to the skin. This not only hinders sweat evaporation but also creates a feeling of restriction during exercise due to increased friction, affecting the wearer's comfort. Summary of the Invention

[0005] The purpose of this invention is to provide a method for preparing a highly breathable and UV-resistant fabric, which has the advantages of combining excellent and durable UV resistance with physical breathability, as well as dynamically adjusting thermal and moisture comfort and preventing sticking.

[0006] The above-mentioned technical objective of the present invention is achieved through the following technical solution:

[0007] A method for preparing a highly breathable and UV-resistant fabric includes the following steps:

[0008] Step S1: Prepare UV-resistant nylon filament;

[0009] Titanium dioxide UV inhibitor was blended and melted with nylon chips, and then spun using a shaped spinneret to prepare UV-resistant nylon filaments with a flat cross-section structure.

[0010] Step S2: Process segmented variable twist warp yarns;

[0011] UV-resistant nylon filament was selected as the warp yarn substrate, and an intermittent untwisting process was performed on the warp yarn substrate to form a segmented variable twist warp with a segmented variable twist diameter structure along the length direction of the warp yarn substrate. The segmented variable twist diameter structure consists of twisted dense sections and untwisted loose sections that are alternately distributed along the yarn axis. Among them, the twist of the twisted dense section is 800 twists / meter to 1200 twists / meter, and the length ratio of the twisted dense section to the untwisted loose section is 1:1.5 to 1:2.5.

[0012] Step S3: Process the elastic core-spun weft yarn;

[0013] Using spandex filament as the core yarn and UV-resistant nylon filament as the outer covering layer, the first weft yarn and the second weft yarn are prepared by machine wrapping and twisting process respectively;

[0014] Step S4, Differentiated tension weaving: The segmented twisted warp yarn, the first weft yarn, and the second weft yarn are interwoven on the machine; during the interweaving process, the first weft yarn and the second weft yarn are introduced alternately, and the weaving tension of the second weft yarn is controlled to be lower than that of the first weft yarn, so as to induce the fabric surface to form a three-dimensional micro-wrinkle structure by utilizing the tension difference.

[0015] Step S5: Heat setting treatment;

[0016] The woven fabric is then subjected to high-temperature setting, utilizing the shrinkage characteristics of spandex yarn and the structural characteristics of segmented variable twist warp yarns to fix the three-dimensional micro-wrinkle structure.

[0017] Further details: In step S1, the preparation process of the UV-resistant nylon filament includes the following sub-steps:

[0018] S11, Powder pretreatment;

[0019] Before blending, the titanium dioxide UV stabilizer was surface modified with a silane coupling agent and a high-concentration masterbatch with a titanium dioxide mass concentration of 20%-25% was prepared.

[0020] S12, shear temperature-controlled spinning;

[0021] High-concentration masterbatch is mixed with nylon chips and fed into a twin-screw extruder. The temperature of the shear section of the twin-screw extruder is set to be 5℃-8℃ lower than that of the melting section. Under high shear conditions, the high-concentration masterbatch is dispersed and extruded through the shaped spinneret holes on the shaped spinneret plate. The aspect ratio of the cross-section of the shaped spinneret holes is 1:5.

[0022] Further settings: Step S2, which involves processing segmented twisted warp yarns, also includes a sub-step:

[0023] S21, Intermittent network hardening;

[0024] After performing the intermittent untwisting process and before the warp yarns are woven on the loom, the segmented twisted warp yarns are passed through the network nozzles;

[0025] S22, Pressure Pulse Control:

[0026] The air pressure of the network nozzle is controlled to synchronize with the intermittent untwisting process; when the twisted and dense section of the segmented variable twist warp passes through, the air pressure is turned off; when the untwisted and fluffy section passes through, the airflow of 0.1MPa-0.2MPa is turned on to form network nodes with a predetermined spacing on the untwisted and fluffy section; the network strength of the network nodes is controlled at 3-5 nodes / meter, and the critical disintegration temperature of the network nodes is 80℃-100℃.

[0027] Further setup: In step S4, the differentiated tension weaving includes the following sub-steps:

[0028] S41, Attitude compensation;

[0029] The weaving equipment uses an air-jet loom, with the main nozzle air pressure of the second weft yarn set to be 20%-30% lower than that of the main nozzle of the first weft yarn;

[0030] S42, End-of-line anti-rebound control;

[0031] Increase the air pressure flow of the last three sets of auxiliary nozzles located on the weft yarn arrival side of the weft insertion channel, and delay the closing time of the auxiliary nozzles by 5ms-10ms, using the terminal airflow to pull the second weft yarn until it reaches the endpoint.

[0032] Further settings: In step S5, the heat setting process includes the following sub-steps:

[0033] S51, Oscillating loose pre-shrinkage;

[0034] Before high-temperature setting, the fabric is placed in a loose dryer and patted and vibrated at a frequency of 30Hz-50Hz at an environment of 160℃-170℃ to pre-shrink the spandex yarn and the untwisted and fluffy section.

[0035] S52, stepped design;

[0036] It then enters the stenter, where the overfeed rate is controlled at 20%-30%, the stenting temperature is set at 185℃-190℃, and the stenting time is controlled at 20-30 seconds for stretching and stenting.

[0037] Further steps include: after the heat setting process in step S5, step S6, functional protection finishing;

[0038] The heat-set fabric is introduced into the padding tank and impregnated with a waterproof and oil-repellent finishing agent. During the padding process, the roll-off rate is controlled at 60%-70%. Subsequently, it is dried and baked at a temperature of 160℃-170℃ for 45-60 seconds.

[0039] Further setting: In step S1, the percentage of titanium dioxide UV stabilizer to the total mass of titanium dioxide UV stabilizer and nylon chips is 5% to 6.5%.

[0040] Further setting: In step S1, the nylon chips are semi-dull nylon chips;

[0041] In step S2, the warp substrate is made of UV-resistant nylon filament with a specification of 15D / 24F;

[0042] In step S3, the outer covering layer of the first weft yarn is made of UV-resistant nylon filament with a specification of 20D / 24F, and the outer covering layer of the second weft yarn is made of UV-resistant nylon filament with a specification of 40D / 34F.

[0043] Further settings: In step S4, the weaving structure cycle is set to 12×24; the first weft yarn and the second weft yarn are introduced alternately at a weft insertion ratio of 10:2.

[0044] Another object of the present invention is to provide a highly breathable and UV-resistant fabric, which is prepared by the method described above.

[0045] In summary, the present invention has the following beneficial effects:

[0046] First, existing technologies often employ post-treatment coatings, leading to clogged pores and poor washability. In this invention, step S1 involves blending and melting titanium dioxide UV-resistant agent with nylon chips to prepare flat-section filaments. Utilizing the large specific surface area of ​​the flat filaments to create a scaly physical covering effect, excellent UV resistance is achieved without relying on a thick coating. This avoids the clogging of micropores between fibers caused by the coating process, while ensuring the durability of the UV-resistant function and washability. This solves the technical problem of traditional sun-protective fabrics where breathability and sun protection effectiveness are difficult to achieve simultaneously.

[0047] Traditional warp yarns have uniform twist and extremely small fiber gaps at high densities. By performing an intermittent untwisting process on the warp yarn substrate in step S2, an alternating structure of twisted and dense sections and untwisted and loose sections is constructed along the yarn axis. Utilizing the naturally loose state of the fibers in the untwisted and loose sections, a large number of native breathable channels are formed inside the fabric, significantly improving the fabric's gaseous moisture conduction capacity and achieving physical breathability under high opacity.

[0048] Traditional fabrics are smooth and tend to cling to the skin when wet. By using a differentiated tension weaving process in step S4, which controls the tension of the second weft yarn to be lower than that of the first weft yarn, and combined with the heat setting treatment in step S5, the tension difference and the thermal shrinkage characteristics of spandex yarn are utilized to create a stable three-dimensional micro-wrinkled structure on the fabric surface. This significantly reduces the contact area between the fabric and the human skin, forming a microscopic air barrier layer. This prevents the fabric from clinging to the skin and causing a damp, cold, and restrictive feeling when the body sweats heavily.

[0049] The elastic core-spun weft yarn prepared in step S3 and the segmented twisted warp yarn prepared in step S2 interweave with each other, giving the fabric a dynamic adjustment and breathability. When the fabric is stretched by force as the human body moves, the elastic extension of the weft yarn causes the untwisted and fluffy section of the warp yarn to expand laterally, which increases the pore size of the breathable micropores, thereby meeting the high heat dissipation requirements during peak exercise and improving the wearer's thermal and moisture comfort.

[0050] Secondly, regarding step S11, titanium dioxide is a high-surface-energy inorganic polar material, while nylon chips are a low-surface-energy organic polymer. Titanium dioxide UV stabilizers and nylon chips are thermodynamically incompatible and prone to agglomeration under high-concentration filling conditions. Through the molecular structure of the silane coupling agent, one end can chemically bond with the hydroxyl groups on the surface of titanium dioxide, while the other end's organic functional groups can physically entangle or chemically react with the nylon molecular chains. The molecular bridging effect of the silane coupling agent can significantly reduce the potential energy difference at the interface between the two phases, inhibiting secondary agglomeration of particles at the source and effectively reducing the surface energy and interfacial tension of the filler in high-concentration masterbatch.

[0051] Regarding step S12, during twin-screw extrusion, the magnitude of shear stress is directly proportional to the melt viscosity and shear rate. By setting the shear zone temperature lower than the melting zone temperature, a controlled high-viscosity environment is created in the shear mixing zone by utilizing the rheological property that the polymer melt viscosity increases with decreasing temperature. At high viscosity, the mechanical shear stress applied to the melt by the screw rotation can be more effectively transferred to the interior of the titanium dioxide agglomerates, forcibly breaking them down and dispersing them. This helps to eliminate melt pressure fluctuations caused by particle agglomeration, ensuring that the melt containing high filler content can smoothly pass through the irregularly shaped spinneret orifice with an aspect ratio of 1:5, avoiding spinneret orifice blockage and excessive component pressure. This achieves the continuous and stable production of high-quality flat cross-section UV-resistant nylon filaments.

[0052] Third, although the untwisted and fluffy section provides breathable micropores for the fabric, the fibers within this section are in a loose and uncoordinated state. During weaving, they are unable to withstand the mechanical tension and friction generated by high-speed weft insertion, easily leading to fuzz accumulation and even fiber breakage. By utilizing the intermittent network reinforcement and pressure pulse control process in steps S21 and S22, the intermittent pulsed airflow acts on the fiber bundle, using low-pressure airflow to construct physical entanglements, i.e., network nodes, in the fluffy section. This network node structure enhances the cohesion of the fluffy section and its resistance to damage caused by friction, reducing the breakage rate and downtime rate during weaving.

[0053] Furthermore, the critical disintegration temperature of the network nodes is set to 80 to 100 degrees Celsius. The critical disintegration temperature range is significantly higher than the weaving environment temperature but much lower than the high-temperature environment of heat setting in step S5. By utilizing the stress relaxation and chain segment movement characteristics of nylon fibers under heat, it is ensured that the network nodes will automatically disintegrate due to thermal movement and return to a loose fiber arrangement after completing the weaving mission. This ensures smooth weaving while avoiding permanent nodes from blocking or damaging the breathable micropores of the finished fabric, thus achieving a balance between high weaveability and high breathability of the fabric.

[0054] Fourth, by reducing the air pressure of the second weft yarn main nozzle in step S41, the initial flight acceleration and kinetic energy of the weft yarn are reduced, thereby establishing a tension difference between the second weft yarn and the first weft yarn, providing the necessary mechanical basis for the formation of the three-dimensional micro-wrinkle effect of the finished fabric. At the same time, taking into account the characteristic that elastic yarns are prone to elastic shrinkage and weft shrinkage defects under low tension, the end anti-rebound control process in step S42 is used to increase the air pressure and flow rate of the last three sets of auxiliary nozzles and delay the closing time. During the critical window period at the end of weft insertion, the strong airflow at the end applies axial pneumatic traction force to the second weft yarn with decaying kinetic energy. This end compensation effectively overcomes the shrinkage tendency of the low-tension weft yarn due to its own elastic recovery force, forcibly straightening the weft yarn until the weft end closes. Thus, while ensuring low-tension weaving conditions, weaving defects such as missing weft, weft shrinkage, and fabric arching are effectively avoided.

[0055] Fifth, the present invention utilizes the oscillating loose pre-shrinking process in step S51 to introduce mechanical beating and oscillation of 30 Hz to 50 Hz in a high-temperature loose environment. By utilizing the coupling effect of mechanical energy and thermal energy, the frictional resistance at the fiber interlacing point is effectively overcome, so that the spandex yarn and the untwisted and fluffy section can generate the maximum degree of free shrinkage. Thus, a fluffy micro-basic morphology is pre-constructed before shaping, avoiding the defect of traditional stretching process where the micro-wrinkle structure is straightened before it is formed due to forced traction.

[0056] By utilizing the stepped setting process in step S52, a low-tension heat treatment environment matching the pre-shrinkage range of the fabric is formed by setting a high temperature of 185 to 190 degrees Celsius and an overfeed rate of 20% to 30%. This avoids the forced flattening of the three-dimensional structure caused by excessive warp tension in the traditional stretching process. During the recrystallization of nylon fibers, the microscopic relaxation and shrinkage morphology is solidified into a macroscopic permanent three-dimensional micro-wrinkle structure, ensuring the fluffiness of the finished fabric and the structural integrity of the breathable micropores.

[0057] Sixth, regarding step S6, the present invention addresses the issue that the fabric has already formed crucial physically permeable micropores through previous processes. If a conventional high-residue process, which aims for high protective effects, is followed, excessive finishing liquid will fill the fiber gaps and micropores under capillary pressure and form a continuous polymer sealing film under thermal induction, thereby blocking the air permeability channels. By reducing the residue rate to 60% to 70%, the amount of liquid on the fabric surface is controlled to be in an unsaturated state. The surface tension of the liquid allows the finishing agent to be preferentially adsorbed and coated on the surface of individual fibers, rather than filling the gaps in the fiber aggregate. This avoids the physical blocking of the permeable micropores in the untwisted and fluffy sections of the segmented twisted warp yarns. Combined with a baking process at 160°C to 170°C, the finishing agent is cross-linked and cured in situ on the surface of individual fibers. This not only imparts excellent waterproof and oil-repellent properties to the fabric but also maximizes the preservation of the air permeability channels in the fabric's physical structure, achieving a synergistic coexistence of high protective function and high breathability.

[0058] Seventh, conventional matte fibers typically have low titanium dioxide content, making it difficult to achieve high-level sun protection standards. This application addresses this by increasing the titanium dioxide content to a high-filling range of 5% to 6.5%. This utilizes the near-saturated physical shielding network formed by titanium dioxide particles in the fiber matrix at this concentration to maximize photon scattering paths and block ultraviolet rays. Simultaneously, it balances the negative impact of high filler content on melt spinnability and fiber strength, establishing this ratio as a equilibrium point that balances high protection with industrial-scale production.

[0059] The warp yarns are made of extremely fine 15D yarn, forming a soft base with low bending stiffness, making it highly susceptible to buckling deformation induced by external forces. The weft yarn system uses two specifications: 20D and 40D. The 40D coarse weft yarn acts as a rigid skeleton in the fabric, while the 20D fine weft yarn acts as a flexible connection for the filling units. The combination of coarse and fine yarns creates a modulus gradient and shrinkage stress difference within the fabric.

[0060] By setting a large 12x24 repeat structure and a 10:2 weft ratio (ten high-tension fine weft yarns paired with two low-tension coarse weft yarns), this asymmetrical arrangement creates periodic stress concentration and relaxation areas in the warp direction of the fabric. This allows the strong shrinkage force generated by the two coarse weft yarns to be concentrated on the area covered by the ten fine weft yarns, causing the warp yarns to flex and bulge regularly. This results in a delicate, uniform, and three-dimensional micro-wrinkled texture, which not only improves the fabric's sun protection coverage but also optimizes breathability and heat dissipation by reducing the skin contact area. Attached Figure Description

[0061] Figure 1 This is a process flow diagram of the present invention;

[0062] Figure 2 This is a schematic diagram of the microstructure of the segmented variable twist warp yarn of the present invention;

[0063] Figure 3 This is a diagram of the fabric structure of the present invention. Detailed Implementation

[0064] The present invention will be further described in detail below with reference to specific embodiments. These specific embodiments are merely illustrative of the invention and are not intended to limit the invention.

[0065] I. Raw Material and Testing Standards;

[0066] The main raw material specifications used in this embodiment are as follows:

[0067] Nylon chips: Semi-dull PA6 chips with a relative viscosity of 2.45 were selected.

[0068] Titanium dioxide UV stabilizer: Nanoscale rutile titanium dioxide with an average particle size of 30nm is selected.

[0069] Silane coupling agent: KH-550 model is selected.

[0070] Spandex yarn: 20D polyurethane elastic fiber.

[0071] Waterproof and oil-resistant finishing agent: Select C6 series waterproof agent.

[0072] II. Example of preparation of UV-resistant nylon filament;

[0073] Preparation Example 1;

[0074] This preparation example is used to prepare three different specifications of UV-resistant nylon filaments as raw materials for subsequent weaving.

[0075] First, a powder pretreatment step is performed: titanium dioxide UV stabilizer is placed in a high-speed mixer, and 1.5% of silane coupling agent KH-550 (by mass of titanium dioxide) is sprayed in. The mixture is stirred at high speed at 80°C for 20 minutes to prepare surface-modified titanium dioxide powder. Then, the powder is mixed with PA6 carrier and granulated by twin-screw extruder to prepare a high-concentration masterbatch with a titanium dioxide mass concentration of 25%.

[0076] The subsequent shear-temperature controlled spinning step involves mixing the high-concentration masterbatch with semi-dull nylon chips in a specific ratio, controlling the titanium dioxide content in the final fiber to 6.0%. The mixture is then fed into a twin-screw extruder. The melt temperature of the twin-screw extruder is set to 255°C, and the shear temperature is set to 248°C, ensuring that the shear temperature is 7°C lower than the melt temperature. The melt is then extruded through a metering pump and a shaped spinneret with shaped spinneret orifices. The aspect ratio of the shaped spinneret orifices is set to 1:5.

[0077] After the extruded melt is cooled by side blowing, oiled, and drawn, three specifications of flat cross-section UV-resistant nylon filaments are prepared by adjusting the component flow rate and draw ratio:

[0078] UV-resistant nylon filament with specifications of 15D / 24F is used as the warp yarn substrate.

[0079] UV-resistant nylon filament with specifications of 20D / 24F is used as the outer covering layer of the first weft yarn.

[0080] UV-resistant nylon filament with specifications of 40D / 34F is used as the outer covering layer of the second weft yarn.

[0081] Preparation Example 2;

[0082] This preparation example serves as a comparative sample. The only difference from Preparation Example 1 is that a common circular spinneret is used for spinning, while the other process parameters remain the same, resulting in a circular cross-section UV-resistant nylon filament.

[0083] Preparation Example 3;

[0084] This preparation example serves as a comparative sample. The only difference from Preparation Example 1 is that the temperature of the shearing section of the twin-screw extruder is set to 255°C, which is the same as the temperature of the melting section, and no silane coupling agent is used for pretreatment.

[0085] III. Fabric Preparation Examples;

[0086] Example 1;

[0087] This embodiment provides a method for preparing a highly breathable and UV-resistant fabric, such as... Figure 1 As shown, the specific steps are as follows:

[0088] Step S1: Prepare UV-resistant nylon filament;

[0089] Three types of UV-resistant nylon filaments with specifications of 15D / 24F, 20D / 24F and 40D / 34F were prepared using the method of Preparation Example 1.

[0090] Step S2: Process segmented variable twist warp yarns;

[0091] UV-resistant nylon filament with a specification of 15D / 24F was selected as the warp yarn substrate, and an intermittent untwisting process was performed. The twist of the dense twisting section was set to 1000 twists / meter and the length to be 10mm; the twist of the loose untwisting section was set to 0 and the length to be 20mm; the length ratio of the dense twisting section to the loose untwisting section was 1:2.

[0092] like Figure 2As shown, the warp yarns exhibit periodic morphological changes along their length: the narrower sections correspond to the twisted and denser sections, where the fibers are tightly bound together to provide strength; the wider and thicker gourd-shaped sections correspond to the untwisted and fluffy sections, where the fibers are in a loose, untwisted state, providing physical space for the subsequent formation of breathable micropores.

[0093] During this process, intermittent network reinforcement is performed: when the untwisted and fluffy section passes through the network nozzle, an airflow of 0.15MPa is activated for pressure pulse control to form a network node with a network strength of 4 nodes / meter, and the critical disintegration temperature of the network node is 90℃.

[0094] Step S3: Process the elastic core-spun weft yarn;

[0095] Preparation of the first weft yarn: 20D spandex yarn is used as the core yarn, and 20D / 24F UV-resistant nylon filament is used as the outer covering layer. The spandex yarn draw ratio is set to 3.0 times, and the twist of the outer covering layer and the core yarn is 700 twists / meter.

[0096] Preparation of the second weft yarn: 20D spandex yarn is used as the core yarn, and 40D / 34F UV-resistant nylon filament is used as the outer covering layer. The spandex yarn draw ratio is set to 3.0 times.

[0097] Step S4: Differentiated tension weaving;

[0098] The weaving is performed using an air-jet loom, with the weaving cycle set to 12×24, such as... Figure 3 As shown, the vertical direction represents the warp yarn, and the horizontal direction represents the weft yarn. The light-colored horizontal stripes numbered 1-10 represent the first weft yarn, and the dark-colored horizontal stripes numbered 11-12 represent the second weft yarn. As can be seen from the diagram, the first and second weft yarns are introduced alternately in a strict 10:2 ratio. This asymmetrical arrangement, combined with differentiated tension, is key to forming the three-dimensional micro-wrinkles.

[0099] Perform attitude compensation: Set the main nozzle air pressure of the first weft yarn to 0.45MPa and the main nozzle air pressure of the second weft yarn to 0.32MPa. The air pressure of the second weft yarn is about 29% lower than that of the first weft yarn.

[0100] Execute end-of-line anti-rebound control: Increase the air pressure flow rate of the last three sets of auxiliary nozzles located on the weft yarn arrival side of the weft insertion channel to 0.5MPa, and delay the closing time of the auxiliary nozzles by 8ms.

[0101] Step S5: Heat setting treatment;

[0102] Perform oscillating loose pre-shrinking: Before high-temperature setting, place the fabric in a loose dryer and pat and oscillate the fabric at a frequency of 40Hz at 165℃.

[0103] Perform stepped shaping: Then enter the shaping machine, set the shaping temperature to 188℃, the shaping time to 25 seconds, and the overfeed rate to 25%.

[0104] Step S6: Functional protection and maintenance;

[0105] The heat-set fabric is introduced into a padding tank and impregnated with a waterproof and oil-repellent finishing agent. During the padding process, the roll-off rate is controlled at 65%. It is then dried and baked at 165℃ for 50 seconds.

[0106] Example 2;

[0107] The difference from Example 1 is that some process parameters have been adjusted;

[0108] In step S1, the content of titanium dioxide UV stabilizer is set to 5.0%;

[0109] In step S2, the twist of the twisted and dense section is set to 800 twists / meter, and the length ratio is set to 1:1.5;

[0110] In step S4, the main nozzle air pressure of the second weft yarn is 20% lower than that of the main nozzle of the first weft yarn;

[0111] In step S5, the overfeed rate of the setting machine is set to 20%;

[0112] In step S6, the roll allowance during the dip rolling process is controlled at 60%.

[0113] The remaining steps are consistent with those in Example 1.

[0114] Example 3;

[0115] The difference from Example 1 is that some process parameters have been adjusted;

[0116] In step S1, the content of titanium dioxide UV stabilizer is set to 6.5%;

[0117] In step S2, the twist of the twisted and dense section is set to 1200 twists / meter, and the length ratio is set to 1:2.5;

[0118] In step S4, the air pressure of the main nozzle of the second weft yarn is 30% lower than that of the main nozzle of the first weft yarn;

[0119] In step S5, the overfeed rate of the setting machine is set to 30%;

[0120] In step S6, the roll allowance during the dip rolling process is controlled at 70%.

[0121] The remaining steps are consistent with those in Example 1.

[0122] IV. Comparative Examples;

[0123] To verify the effectiveness of the key technical features of this invention, the following comparative examples are provided:

[0124] Comparative Example 1;

[0125] This comparative example is used to verify the impact of the flat cross-section structure resulting from the irregular spinneret orifice on performance. The only difference from Example 1 is that the circular cross-section filament prepared in Preparation Example 2 is used in step S1, while the other steps are the same as in Example 1.

[0126] Comparative Example 2;

[0127] This comparative example is used to verify the effect of segmented variable twist warp on air permeability. The only difference from Example 1 is that in step S2, the warp substrate is continuously and uniformly twisted at a twist rate of 1000 twists / meter, without forming a segmented variable twist differential structure. The remaining steps are the same as in Example 1.

[0128] Comparative Example 3;

[0129] This comparative example is used to verify the effect of differentiated tension weaving on the three-dimensional micro-wrinkle structure and anti-adhesion properties. The only difference from Example 1 is that in step S4, the air pressure of the main nozzles of the first and second weft yarns is set to 0.45 MPa, that is, no weaving tension difference is formed. The remaining steps are the same as in Example 1.

[0130] Comparative Example 4;

[0131] This comparative example is used to verify the effect of roll residue control on microporous permeability. The only difference from Example 1 is that in step S6, the roll residue is controlled at 85%, and the remaining steps are the same as in Example 1.

[0132] Comparative Example 5;

[0133] This comparative example is used to verify the effect of the intermittent network reinforcement step on weaving stability. The only difference from Example 1 is that the intermittent network reinforcement and pressure pulse control sub-steps are not performed in step S2; the remaining steps are the same as in Example 1.

[0134] Comparative Example 6;

[0135] This comparative example is used to simulate traditional finishing coating processes to verify the durability of the in-situ blended sunscreen and its protection of breathability of the present invention. The difference from Example 1 is that: in step S1, titanium dioxide UV stabilizer is not added, and ordinary nylon filament is prepared; simultaneously, in the functional protective finishing step S6, a conventional UV stabilizer with a mass concentration of 5% is added to the finishing solution for coating. The remaining weaving and setting steps are the same as in Example 1.

[0136] V. Performance testing;

[0137] The performance testing standards used in this embodiment are as follows:

[0138] UV protection performance: Characterized by UPF value, tested according to GB / T 18830-2009 standard.

[0139] Breathability: Tested according to GB / T 5453-1997 standard, with pressure drop set at 100Pa, and breathability rate recorded.

[0140] Cooling sensation upon contact: Characterized by the Qmax value, tested according to GB / T 35263-2017 standard. The higher the value, the faster the heat dissipation.

[0141] Anti-stickiness: Subjective rating based on skin feel under simulated sweating conditions, divided into 1 to 5 levels, with 5 indicating no stickiness.

[0142] Surface moisture resistance: Tested according to GB / T 4745-2012 standard, and the rating before washing was recorded (level 1 to 5, level 4-5 and above indicate excellent moisture resistance).

[0143] Hydrostatic pressure: Tested according to GB / T 4744-2013 standard, and the hydrostatic pressure resistance value (kPa) of the fabric after washing was recorded.

[0144] Moisture permeability: Tested according to GB / T 12704.2-2009 standard (Method B, Condition a).

[0145] Abrasion resistance: Tested according to GB / T 21196.2-2007 standard (Martindale method).

[0146] Color fastness test: Dry rubbing color fastness is tested according to GB / T 3920-2008 standard; perspiration color fastness is tested according to GB / T3922-2013 standard; water color fastness is tested according to GB / T 5713-2013 standard.

[0147] The fabrics obtained in the above embodiments and comparative examples were subjected to performance tests, and the breakage rate during the weaving process was recorded. The test results are shown in Table 1.

[0148] Table 1: Performance test results of the examples and comparative examples;

[0149] Initial UPF value 92 80 105 35 90 88 91 92 95 UPF value after 50 washes 89 77 102 34 87 85 88 89 32 Air permeability (mm / s) 134.7 120 145 130 45 100 75 135 55 Qmax value (J / cm²·s) 0.24 0.22 0.25 0.18 0.16 0.14 0.23 0.24 0.15 Anti-sticking properties (grade) 5 4.5 5 4 3 1.5 5 5 3 Surface moisture resistance (before washing) (Grade) 4-5 4 4-5 4-5 4-5 4-5 4-5 4-5 4-5 Hydrostatic pressure (after washing) (kPa) 158.9 145.0 162.5 155.0 160.2 158.5 185.0 158.8 140.0 Weaving breakage rate (times / 100 meters) 0.5 0.3 0.8 0.5 0.2 0.4 0.5 12.5 0.4

[0150] Analysis of experimental results:

[0151] Example 1 uses a flat cross-section nylon filament with an initial UPF value of 92, while Comparative Example 1 uses a circular cross-section filament with a UPF value of only 35. This indicates that, with the same amount of titanium dioxide added, the flat cross-section structure can produce a stronger physical shielding effect, significantly improving UV resistance.

[0152] Comparative Example 2 eliminated the segmented twisted warp structure, causing the fabric's air permeability to plummet from 134.7 mm / s in Example 1 to 45 mm / s. This verifies that the untwisted, fluffy sections in the segmented twisted warp are key to constructing physically breathable micropores, and this structure effectively breaks down the air barrier layer of high-density fabrics.

[0153] Comparative Example 3 eliminated differentiated tension control, resulting in a fabric Qmax value reduced to 0.14 and an anti-sticking rating of only 1.5. In contrast, Example 1, through the three-dimensional micro-wrinkle structure induced by tension difference, significantly reduced the contact area between the fabric and the skin, improved heat dissipation, and alleviated the feeling of dampness and coldness.

[0154] Comparative Example 4, using a conventional high roll-on rate of 85% in the waterproof and oil-repellent finishing process, achieved a hydrostatic pressure of 185.0 kPa, but the air permeability decreased significantly from 134.7 mm / s in Example 1 to 75 mm / s. This confirms that excessive finishing liquid forms a film during drying, clogging the breathable micropores. In contrast, Example 1 of this invention, using a low roll-on rate of 60% to 70%, maintained the fabric's surface moisture resistance at an excellent level of 4-5, and the hydrostatic pressure remained at a high level of 158.9 kPa after washing, while preserving the high air permeability of 134.7 mm / s, thus balancing moisture resistance and breathability.

[0155] Comparative Example 5 did not perform network reinforcement during warp processing. Although the static indicators of the finished fabric were similar to those of Example 1, the weaving breakage rate was as high as 12.5 times / 100 meters, which could not meet the requirements of industrial production. Example 1 controlled the breakage rate to 0.5 times / 100 meters by constructing metastable network nodes, verifying the decisive role of this step in improving weaving feasibility.

[0156] Combining the data from Example 1 and Comparative Example 6, it can be seen that although Comparative Example 6, using a traditional surface coating process, initially achieved a UPF value of 95, the UPF value plummeted to 32 after 50 washes, with an air permeability of only 55 mm / s; the coating clogged the micropores. In contrast, Example 1 maintained a UPF value of 89 after 50 washes, showing minimal degradation compared to the initial value of 92, with an air permeability as high as 134.7 mm / s. This demonstrates that the present invention's technical solution of blending titanium dioxide and nylon in step S1 embeds the UV-resistant component within the fiber matrix, avoiding the functional degradation and physical blockage of air permeability caused by frequent washing in traditional coating processes.

[0157] In summary, this invention has successfully prepared a functional fabric that combines high breathability, high sun protection, and excellent thermal and moisture comfort by using flat cross-section spinning, segmented variable twisting for hole formation, differentiated tension wrinkling, and low roll-over rate finishing.

[0158] The above embodiments are merely explanations of the present invention and are not intended to limit the present invention. After reading this specification, those skilled in the art can make modifications to these embodiments without contributing any inventive step, but as long as they are within the scope of the claims of the present invention, they are protected by patent law.

Claims

1. A method for preparing a highly breathable and UV-resistant fabric, characterized in that, Includes the following steps: Step S1: Prepare UV-resistant nylon filament; Titanium dioxide UV inhibitor was blended and melted with nylon chips, and then spun using a shaped spinneret to prepare UV-resistant nylon filaments with a flat cross-section structure. Step S2: Process segmented variable twist warp yarns; UV-resistant nylon filament was selected as the warp yarn substrate, and an intermittent untwisting process was performed on the warp yarn substrate to form a segmented twisted warp yarn with a segmented twisted diameter structure in the length direction of the warp yarn substrate. The segmented variable twist and diameter structure consists of alternating twisted dense sections and untwisted loose sections distributed along the yarn axis; wherein, the twist of the twisted dense section is 800 twists / meter to 1200 twists / meter, and the length ratio of the twisted dense section to the untwisted loose section is 1:1.5 to 1:2.

5. Step S3: Process the elastic core-spun weft yarn; Using spandex filament as the core yarn and UV-resistant nylon filament as the outer covering layer, the first weft yarn and the second weft yarn are prepared by machine wrapping and twisting process respectively; Step S4, Differentiated tension weaving: The segmented twisted warp yarn, the first weft yarn, and the second weft yarn are interwoven on the machine; during the interweaving process, the first weft yarn and the second weft yarn are introduced alternately, and the weaving tension of the second weft yarn is controlled to be lower than that of the first weft yarn, so as to induce the fabric surface to form a three-dimensional micro-wrinkle structure by utilizing the tension difference. Step S5: Heat setting treatment; The woven fabric is then subjected to high-temperature setting, utilizing the shrinkage characteristics of spandex yarn and the structural characteristics of segmented variable twist warp yarns to fix the three-dimensional micro-wrinkle structure.

2. The method for preparing the highly breathable and UV-resistant fabric according to claim 1, characterized in that: In step S1, the preparation process of the UV-resistant nylon filament includes the following sub-steps: S11, Powder pretreatment; Before blending, the titanium dioxide UV stabilizer was surface modified with a silane coupling agent and a high-concentration masterbatch with a titanium dioxide mass concentration of 20%-25% was prepared. S12, shear temperature-controlled spinning; High-concentration masterbatch is mixed with nylon chips and fed into a twin-screw extruder. The temperature of the shear section of the twin-screw extruder is set to be 5℃-8℃ lower than that of the melting section. Under high shear conditions, the high-concentration masterbatch is dispersed and extruded through the shaped spinneret holes on the shaped spinneret plate. The aspect ratio of the cross-section of the shaped spinneret holes is 1:

5.

3. The method for preparing the highly breathable and UV-resistant fabric according to claim 1, characterized in that: Step S2, which involves processing segmented twisted warp yarns, also includes the following sub-steps: S21, Intermittent network hardening; After performing the intermittent untwisting process and before the warp yarns are woven on the loom, the segmented twisted warp yarns are passed through the network nozzles; S22, Pressure Pulse Control: The air pressure of the network nozzle is controlled to synchronize with the intermittent untwisting process; when the twisted and dense section of the segmented variable twist warp passes through, the air pressure is turned off; when the untwisted and fluffy section passes through, the airflow of 0.1MPa-0.2MPa is turned on to form network nodes with a predetermined spacing on the untwisted and fluffy section; the network strength of the network nodes is controlled at 3-5 nodes / meter, and the critical disintegration temperature of the network nodes is 80℃-100℃.

4. The method for preparing the highly breathable and UV-resistant fabric according to claim 1, characterized in that: In step S4, the differentiated tension weaving includes the following sub-steps: S41, Attitude compensation; The weaving equipment uses an air-jet loom, with the main nozzle air pressure of the second weft yarn set to be 20%-30% lower than that of the main nozzle of the first weft yarn; S42, End-of-line anti-rebound control; Increase the air pressure flow of the last three sets of auxiliary nozzles located on the weft yarn arrival side of the weft insertion channel, and delay the closing time of the auxiliary nozzles by 5ms-10ms, using the terminal airflow to pull the second weft yarn until it reaches the endpoint.

5. The method for preparing the highly breathable and UV-resistant fabric according to claim 1, characterized in that: In step S5, the heat setting process includes the following sub-steps: S51, Oscillating loose pre-shrinkage; Before high-temperature setting, the fabric is placed in a loose dryer and patted and vibrated at a frequency of 30Hz-50Hz at an environment of 160℃-170℃ to pre-shrink the spandex yarn and the untwisted and fluffy section. S52, stepped design; It then enters the stenter, where the overfeed rate is controlled at 20%-30%, the stenting temperature is set at 185℃-190℃, and the stenting time is controlled at 20-30 seconds for stretching and stenting.

6. The method for preparing the highly breathable and UV-resistant fabric according to claim 1, characterized in that: After the heat setting process in step S5, the process also includes step S6, functional protection finishing. The heat-set fabric is introduced into the padding tank and impregnated with a waterproof and oil-repellent finishing agent. During the padding process, the roll-off rate is controlled at 60%-70%. Subsequently, it is dried and baked at a temperature of 160℃-170℃ for 45-60 seconds.

7. The method for preparing the highly breathable and UV-resistant fabric according to claim 1, characterized in that: In step S1, the percentage of titanium dioxide UV stabilizer in the total mass of titanium dioxide UV stabilizer and nylon chips is 5% to 6.5%.

8. The method for preparing the highly breathable and UV-resistant fabric according to claim 1, characterized in that: In step S1, the nylon chips are semi-dull nylon chips; In step S2, the warp substrate is made of UV-resistant nylon filament with a specification of 15D / 24F; In step S3, the outer covering layer of the first weft yarn is made of UV-resistant nylon filament with a specification of 20D / 24F, and the outer covering layer of the second weft yarn is made of UV-resistant nylon filament with a specification of 40D / 34F.

9. The method for preparing the highly breathable and UV-resistant fabric according to claim 1, characterized in that: In step S4, the weaving structure cycle is set to 12×24; the first weft yarn and the second weft yarn are introduced alternately at a weft insertion ratio of 10:

2.

10. A highly breathable and UV-resistant fabric, characterized in that: It is prepared by the preparation method described in any one of claims 1 to 9.

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