A light, thin and high-breathability knitted fabric and a preparation method thereof

Abstract

The application relates to a light, thin and high-breathability knitted fabric and a preparation method, and relates to the technical field of knitted fabrics.The fabric body is a single-layer knitted structure, and a peripheral stable knitting area, an internal moisture-sensitive deformation area and a moisture-conducting and air-discharging area extending from the moisture-sensitive deformation area to the stable knitting area are formed in the plane direction, and the three are integrally knitted and connected through transition loops, moisture-conducting connecting loops and peripheral transition loops.The moisture-sensitive deformation area is formed by first yarn and second yarn with different moisture absorption deformation rates, and the difference moisture absorption deformation loop is formed, directional displacement is generated after moisture absorption, and the moisture-sensitive deformation hole is actively expanded; the moisture-conducting and air-discharging area forms a moisture-conducting channel with different capillary transmission capacities, so that sweat is diffused from the moisture-sensitive deformation area to the fabric periphery.In the preparation process, the dynamic pore increment is controlled through differential tension knitting, staged heat setting and humidity response calibration, so that the fabric is kept light, thin and stable in a dry state.

Description

Technical Field

[0001] This application relates to the field of knitted fabric technology, and in particular to a lightweight and highly breathable knitted fabric and its preparation method. Background Technology

[0002] With the increasing demands for lightweight, comfort, and breathability in sportswear, outdoor clothing, and summer close-fitting garments, knitted fabrics have gained widespread use due to their superior softness, elasticity, and fit. Existing lightweight and breathable knitted fabrics typically improve breathability and moisture wicking properties by reducing fabric density, increasing the number of mesh openings, using irregularly shaped fibers, or incorporating moisture-wicking yarns. However, the pore structure of these fabrics is usually essentially fixed after fabrication, and their breathability primarily depends on the initial porosity. When the body produces a large amount of sweat during exercise, the sweat easily accumulates within the fiber and fabric pores, leading to increased localized moisture content, obstructed airflow, and difficulty in actively adjusting breathability based on the body's actual perspiration levels.

[0003] In addition, some existing multifunctional knitted fabrics use different functional yarns to combine, which can take into account moisture absorption, moisture wicking and breathability. However, this is usually achieved by layering different yarns or simply splicing different areas. There is a lack of structural synergy between the functional areas, which can easily lead to problems such as increased fabric thickness, complex structure and limited dynamic breathability. Summary of the Invention

[0004] Therefore, it is necessary to provide a lightweight and highly breathable knitted fabric and its preparation method to address the aforementioned technical problems.

[0005] The present application provides a lightweight and highly breathable knitted fabric with the following technical solution: it includes a fabric body, which is a single-layer knitted structure formed by knitting multiple yarns together. The fabric body forms a stable knitting area, at least one moisture-sensitive deformation area and at least one moisture-wicking and exhaust area along its planar direction. The stabilizing weaving zone is located on the periphery of the fabric body and is used to form the main support structure of the fabric body; The moisture-sensitive deformation zone is located within the area enclosed by the stable braiding zone and is integrally braided and connected by the transition coil between the stable braiding zone and the moisture-sensitive deformation zone. The moisture-sensitive deformation zone is formed by alternating loops of the first yarn and the second yarn to create differential moisture-absorbing deformation coils. The moisture absorption deformation rate of the first yarn is greater than that of the second yarn, so that the differential moisture-absorbing deformation coils will undergo directional deformation after absorbing moisture. The moisture-conducting and exhaust zone extends from the moisture-sensitive deformation zone toward the stable braiding zone and is arranged adjacent to the moisture-sensitive deformation zone; the inner end of the moisture-conducting and exhaust zone is integrally braided and connected to the moisture-sensitive deformation zone through a moisture-conducting connecting coil, and the outer end of the moisture-conducting and exhaust zone is integrally braided and connected to the stable braiding zone through an outer transition coil, so as to form a continuous moisture-conducting and exhaust path extending from the moisture-sensitive deformation zone to the stable braiding zone. When the moisture-sensitive deformation zone absorbs moisture, the difference in moisture absorption deformation between the first yarn and the second yarn drives the differential moisture absorption deformation coil to shift in a predetermined direction, thereby increasing the effective pore area between adjacent differential moisture absorption deformation coils and connecting the increased effective pores with the moisture-conducting and exhaust zone to form a ventilation and moisture-removing path that is synchronously enhanced when humidity increases. By adopting the above technical solution, the stable weaving zone, the moisture-sensitive deformation zone, and the moisture-wicking and venting zone are set on the same knitting layer and woven together as a whole, so that the fabric forms an overall structure in which humidity response, dynamic opening and directional moisture wicking work together, thereby improving the dynamic breathability of the fabric.

[0006] Preferably, the first yarn is a moisture-absorbing deformable yarn that shrinks axially after absorbing moisture, and the second yarn is a dimensionally stable yarn whose dimensional change rate after absorbing moisture is lower than that of the first yarn. The difference between the moisture absorption deformation rates of the first yarn and the second yarn is 2% to 12%.

[0007] By adopting the above technical solution, the first yarn and the second yarn form a preset moisture absorption deformation difference, thereby providing a stable and controllable humidity response driving force for the moisture-sensitive deformation zone.

[0008] Preferably, the moisture-sensitive deformation zone includes a first coil unit arranged along a first direction and a second coil unit arranged along a second direction. The first coil unit is formed by a first yarn, and the second coil unit is formed by a second yarn. The first coil unit and the second coil unit are alternately connected to form a plurality of moisture-sensitive deformation holes. The moisture-sensitive deformable pore has a first equivalent pore size in a dry state and a second equivalent pore size in a moisture-absorbing state, wherein the second equivalent pore size is 1.2 to 2.5 times the first equivalent pore size.

[0009] By adopting the above technical solution, the staggered first coil unit and second coil unit form a moisture-sensitive deformation hole that can expand with changes in humidity, thereby realizing the active adjustment of the fabric pore structure.

[0010] Preferably, the transition coil is formed of elastic recovery yarn to limit the deformation of the moisture-sensitive deformation zone in a non-predetermined direction; another set of transition coils is used to continuously connect the moisture-conducting and venting zone with the peripheral stable braiding zone.

[0011] By adopting the above technical solution, the transition coil is used to elastically constrain the moisture-sensitive deformation zone, so that the moisture-sensitive deformation zone mainly deforms along the predetermined direction, and the stability and reversibility of the dynamic opening process are improved.

[0012] Preferably, the moisture-guiding and exhaust zone includes a first moisture-guiding channel and a second moisture-guiding channel extending along the humidity migration direction, wherein the first moisture-guiding channel is formed by a third yarn and the second moisture-guiding channel is formed by a fourth yarn; The third yarn has higher hydrophilicity than the fourth yarn, and the equivalent capillary radius of the first moisture-conducting channel is smaller than that of the second moisture-conducting channel, so that after the liquid enters the moisture-conducting and exhausting zone from the moisture-sensitive deformation zone, a gradient migration is formed between different capillary channels.

[0013] By adopting the above technical solution, a gradient moisture-wicking structure is formed by using moisture-wicking channels with different capillary radii and different hydrophilic properties, thereby promoting the rapid migration of sweat from the moisture-sensitive deformation zone to the moisture-wicking and exhaust zone.

[0014] Preferably, the first moisture-conducting channel and the second moisture-conducting channel are alternately arranged along the humidity migration direction, and the coil spacing of the moisture-conducting and exhaust zones gradually increases along the humidity migration direction, so that a gradually expanding diffusion area is formed during the migration of liquid from the moisture-sensitive deformation zone to the stable braiding zone; The moisture-wicking and exhaust zone has at least one inner end that communicates with the moisture-sensitive deformation hole of the moisture-sensitive deformation zone and one outer end that communicates with the stable braiding zone.

[0015] By adopting the above technical solution, the coil spacing of the moisture-wicking channel gradually increases along the direction of humidity migration, thereby expanding the range of sweat diffusion and reducing the accumulation of sweat in local areas.

[0016] Preferably, the moisture-sensitive deformation zone accounts for 15% to 45% of the fabric body area, the moisture-wicking and exhaust zone accounts for 10% to 30% of the fabric body area, and the remaining area is a stable weaving zone. The fabric body has a thickness of 0.25 to 0.80 mm and a weight of 80 to 180 g / m², and the effective pore area of ​​the fabric body in the hygroscopic state increases by 20% to 100% compared with the dry state.

[0017] By adopting the above technical solutions, the area ratio of the moisture-sensitive deformation zone and the moisture-wicking and air-venting zone, as well as the fabric thickness and weight, are limited, so that the fabric can achieve greater dynamic porosity changes and breathability while maintaining its lightness and thinness.

[0018] The preparation method is as follows: S1. Yarn pretreatment: Tension homogenization treatment is performed on the first yarn, the second yarn, the third yarn, the fourth yarn and the elastic recovery yarn respectively, and the first yarn is subjected to pre-moisture absorption-drying cycle treatment to stabilize the moisture absorption deformation response of the first yarn. S2, outer skeleton weaving: a stable weaving area is formed by weaving with dimensionally stable yarns, and weaving positions for a moisture-sensitive deformation area and a moisture-guiding and exhaust area are reserved inside the stable weaving area; S3, Moisture-sensitive area weaving: The first yarn and the second yarn are fed alternately according to the preset yarn feeding tension difference to form differential moisture-absorbing deformation coils inside the stable weaving area, and the moisture-sensitive deformation area and the stable weaving area are connected as one through the transition coil. S4, Moisture-guiding area weaving: The third and fourth yarns are alternately looped along the direction from the moisture-sensitive deformation zone to the stable weaving zone, so that one end of the moisture-guiding and exhaust zone is connected to the moisture-sensitive deformation zone through the moisture-guiding connecting coil, and the other end is connected to the stable weaving zone through the outer transition coil; S5. Pre-strain setting: The fabric formed by the integral weaving is heat-set in stages, so that the difference in moisture absorption deformation between the first yarn and the second yarn is locked in the moisture-sensitive deformation zone, and the moisture-conducting channels in the moisture-conducting and exhaust zone maintain the predetermined capillary structure. S6. Humidity Response Calibration: The effective pore area of ​​the fabric is detected in both dry and hygroscopic states. Based on the detection results, the feeding tension difference between the first and second yarns and the heat setting parameters are adjusted to achieve the predetermined dynamic air permeability enhancement effect in the moisture-sensitive deformation zone.

[0019] By adopting the above technical solution, an integrated functional structure is formed through outer skeleton weaving, moisture-sensitive area weaving, moisture-wicking area weaving, and pre-strain shaping, so that the prepared fabric has a stable humidity-responsive dynamic opening capability.

[0020] Preferably, in step S3, the feeding tension of the first yarn is 1.10 to 1.40 times that of the feeding tension of the second yarn, and by controlling the difference in the feeding amount of the first yarn and the second yarn, the moisture-sensitive deformation zone forms a preset initial coil spacing. Step S5 includes a first stage of stress relief shaping and a second stage of structural locking shaping. The first stage heat setting temperature is 80-110℃ and the processing time is 30-120s. The second stage heat setting temperature is 120-160℃ and the processing time is 20-90s.

[0021] By adopting the above technical solution, the feeding tension and staged heat setting parameters of different yarns are controlled in a coordinated manner, thereby forming and maintaining the preset deformation difference between the first yarn and the second yarn.

[0022] Preferably, in step S6, the effective pore area A0 of the fabric in the dry state and the effective pore area A1 in the moisture-absorbing state are obtained, and the dynamic pore increase η is calculated: η = (A1 - A0) / A0 × 100%; When η < 20%, increase the feeding tension difference between the first yarn and the second yarn and / or decrease the heat setting temperature of the first stage; when η > 100%, decrease the feeding tension difference and / or increase the heat setting temperature of the first stage, so that the dynamic porosity increase η is controlled within the range of 20% to 100%, thereby obtaining a humidity-responsive knitted fabric with active increase in effective porosity after moisture absorption.

[0023] By adopting the above technical solution, the weaving and shaping parameters are adjusted based on the difference in effective pore area between the dry and hygroscopic states, thereby controlling the dynamic pore increase within a predetermined range and improving the consistency and repeatability of the fabric's dynamic breathability.

[0024] In summary, this application includes the following beneficial technical effects: By adopting a structure in which the stable knitting zone, moisture-sensitive deformation zone, and moisture-wicking and venting zone are functionally divided and knitted together in the same knitting layer, the traditional multi-layer overlapping structure is avoided, thus reducing the fabric thickness and structural complexity while maintaining the overall stability of the fabric.

[0025] By employing a differential moisture-absorbing deformation structure between the first and second yarns, the moisture-sensitive deformation zone undergoes directional coil displacement after moisture absorption, thereby actively expanding the moisture-sensitive deformation holes and achieving a dynamic air permeability effect that increases synchronously with humidity.

[0026] By employing a structure that uses a stable braided zone to constrain the moisture-sensitive deformation zone, the disordered deformation of the moisture-sensitive deformation zone can be limited, ensuring that moisture absorption deformation mainly occurs along a predetermined direction, thereby improving the controllability and repeatability of the dynamic opening process.

[0027] By employing a moisture-guiding and exhaust zone that extends from the moisture-sensitive deformation zone to the outer stable weaving zone, the dynamically expanding moisture-sensitive deformation holes are kept connected to the moisture-guiding channels, thereby forming a continuous path for moisture absorption, opening, guiding, and exhaust.

[0028] By employing a first moisture-conducting channel and a second moisture-conducting channel with different capillary transmission capabilities, the differences in capillary structure are utilized to promote the diffusion of sweat from the moisture-sensitive deformation zone to the periphery, reducing the stuffy feeling caused by sweat accumulation in local areas.

[0029] By employing differential tension weaving, staged heat setting, and humidity response calibration processes, the initial deformation state and dynamic porosity increase of the moisture-sensitive deformation zone can be adjusted, thereby improving the consistency and repeatability of the fabric's dynamic breathability.

[0030] Through the aforementioned humidity-responsive dynamic opening mechanism, the fabric maintains a thin and stable structure when dry, and automatically increases the effective pores and enhances air exchange capacity after the body sweats, thus taking into account lightness, breathability, moisture wicking and wearing comfort. Attached Figure Description

[0031] Figure 1 This is a schematic diagram of the overall structure of this application.

[0032] Explanation of the attached diagram labels: Stable braided area -1, Moisture-sensitive deformation area -2, Moisture-conducting and exhaust area -3, Transition coil -4. Detailed Implementation

[0033] The present invention will be further described below with reference to specific embodiments. This embodiment provides a lightweight and highly breathable knitted fabric and its preparation method. The fabric is made of a single-layer weft-knitted structure. Its core lies in stabilizing the spatial partitioning and coil connection relationship between the knitting area 1, the moisture-sensitive deformation area 2, and the moisture-wicking and venting area 3, so that the fabric maintains a lightweight and stable structure in a dry state. When the human body sweats and the local humidity increases, the moisture-sensitive deformation area 2 undergoes directional shrinkage, thereby actively expanding the local knitted pores and connecting the expanded pores with the moisture-wicking and venting area 3, allowing liquid sweat and water vapor to migrate to the outside of the fabric in a predetermined direction.

[0034] In this embodiment, the fabric body adopts a single-layer weft-knitted structure without independent interlayers, bonding layers, or spacers. The fabric body is divided along its planar direction into an outer stable knitting area 1, a moisture-sensitive deformation area 2 located inside the stable knitting area 1, and a moisture-wicking and venting area 3 extending from the moisture-sensitive deformation area 2 to the stable knitting area 1. The stable knitting area 1 serves as the outer supporting skeleton of the entire fabric, and it is based on the knitting of a second yarn with high dimensional stability. The moisture-sensitive deformation area 2 is located in the inner area enclosed by the stable knitting area 1, and is formed by alternating loops of the first and second yarns to create differential moisture-wicking deformation loops. The moisture-wicking and venting area 3 extends from the moisture-sensitive deformation area 2 to the outer stable knitting area 1 in a strip-like or finger-like structure, with its inner end connected to the moisture-sensitive deformation area 2 and its outer end connected to the outer stable knitting area 1. Thus, the three areas are not stacked one on top of the other, but rather form functional partitions in the same knitting layer in a planar direction.

[0035] Specifically, the stabilizing weave zone 1 is located on the periphery of the fabric body and forms a continuous boundary skeleton. In this embodiment, the width of the stabilizing weave zone 1 is 15-30 mm, and it uses low moisture absorption and dimensionally stable polyester fiber yarn to form the basic loops. The function of the stabilizing weave zone 1 is not to prevent the moisture-sensitive deformation zone 2 from deforming, but to form an external constraint on the moisture-sensitive deformation zone 2 through its own high structural stability, so that the deformation of the moisture-sensitive deformation zone 2 mainly occurs along the predetermined opening direction, without causing a large-scale warping or overall shrinkage of the entire fabric.

[0036] A transition loop 4 is provided between the stable knitting zone 1 and the moisture-sensitive deformation zone 2. The transition loop 4 is formed of elastic recovery yarn, preferably a covered elastic yarn, wherein the linear density of the elastic core yarn is 20-40D, and the outer covering fiber is polyester or nylon fiber. The width of the transition loop 4 is controlled to be 3-8mm. A portion of the loops of the transition loop 4 share adjacent needle positions with the outer stable knitting zone 1 to form a continuous loop, while another portion of the loops are nested with the edge loops of the moisture-sensitive deformation zone 2. This ensures that the stable knitting zone 1 and the moisture-sensitive deformation zone 2 are not connected by sewing or gluing, but are directly integrated during the knitting process. The transition loop 4 also elastically constrains the edge of the moisture-sensitive deformation zone 2, causing the moisture-sensitive deformation zone 2 to expand its pores mainly in a predetermined direction after absorbing moisture.

[0037] The moisture-sensitive deformation zone 2 is the core functional area of ​​this embodiment. The moisture-sensitive deformation zone 2 is located in the internal area enclosed by the outer stable weaving zone 1, and its area accounts for approximately 25% to 35% of the total area of ​​the fabric body. The moisture-sensitive deformation zone 2 is formed by alternating weaving of a first yarn and a second yarn, wherein the first yarn is a highly moisture-absorbing deformation yarn with wet shrinkage characteristics, and the second yarn is a dimensionally stable yarn.

[0038] In this embodiment, the first yarn is a high-twist regenerated cellulose fiber yarn, whose fiber components can be viscose fiber or modal fiber, with a yarn linear density of 30-50S and a twist coefficient controlled at 380-480 twists / meter. By increasing the twist of the first yarn, the yarn undergoes wet relaxation and axial shrinkage after moisture absorption, and its axial deformation rate under specified humidity conditions is controlled at 4%-8%. The second yarn is made of 20-40D polyester filament or low-moisture-absorbing nylon filament, and its dimensional change rate under the same humidity conditions is controlled at 0.5%-1.5%, thereby creating a moisture absorption deformation difference of about 3%-7% between the first and second yarns.

[0039] The first and second yarns do not form two separate fabric layers, but rather alternately loop within the same knit layer. Specifically, an electronic needle selection method controls the loop positions of the first and second yarns, causing the first yarn to form a first loop unit and the second yarn to form a second loop unit. These first and second loop units are arranged in intersecting directions, thus forming multiple rhomboid or near-rhomboid moisture-sensitive deformation holes. Each moisture-sensitive deformation hole is defined by at least four adjacent loop units.

[0040] In a dry state, since there is no significant difference in wet deformation between the first and second yarns, the first and second coil units maintain relatively close initial positions, resulting in a small initial equivalent aperture for the moisture-sensitive deformation hole. In this embodiment, the equivalent aperture of the moisture-sensitive deformation hole in the dry state is controlled between 0.20 and 0.45 mm. After the wearer wears the garment, when sweat or high-humidity air enters the moisture-sensitive deformation zone 2, the first yarn absorbs moisture and undergoes axial contraction, while the second yarn experiences less dimensional change. Since both yarns participate in the same coil structure, the contraction of the first yarn causes adjacent coils to rotate and shift. Simultaneously, the outer stabilizing braiding zone 1 and the transition coil 4 restrict the diffusion of this displacement in a non-predetermined direction, causing the coil displacement to primarily manifest as the expansion of the moisture-sensitive deformation hole along its opening direction.

[0041] Under relative humidity conditions of 75%–90%, the deformation difference between the first and second yarns increases the equivalent pore size of the moisture-sensitive deformable hole from 0.20–0.45 mm to 0.35–0.90 mm. For a moisture-sensitive deformable hole with an initial pore size of 0.30 mm, its equivalent pore size after moisture absorption can reach 0.50–0.65 mm, thus significantly increasing the local effective pore area. Since this pore change is not generated by external mechanical stretching but driven by the moisture-absorbing deformation of the first yarn itself, it can automatically improve the air exchange capacity of the fabric when human sweat increases.

[0042] To enable the dynamic pores generated in the moisture-sensitive deformation zone 2 to form a continuous moisture exhaust path with the external area, a moisture-guiding and exhaust zone 3 is provided between the moisture-sensitive deformation zone 2 and the outer stable braided zone 1. In this embodiment, the moisture-guiding and exhaust zone 3 uses 4 to 8 parallel or radially distributed moisture-guiding strips. The width of each moisture-guiding strip is 3 to 8 mm, and its inner end is connected to the moisture-sensitive deformation zone 2, while its outer end extends to the outer stable braided zone 1.

[0043] The moisture-wicking and venting zone 3 is not an independent moisture-wicking layer attached to the fabric surface, but is knitted synchronously with the moisture-sensitive deformation zone 2 and the stable knitting zone 1. The inner end of the moisture-wicking and venting zone 3 uses a moisture-wicking connecting coil nested with the edge coil of the moisture-sensitive deformation zone 2, so that the dynamic pores generated by the moisture-sensitive deformation zone 2 can be directly connected to the moisture-wicking and venting zone 3; the outer end of the moisture-wicking and venting zone 3 uses another set of transition coils connected to the outer stable knitting zone 1, so that the moisture-wicking and venting zone 3 maintains a continuous, integrated knitted structure along its entire length.

[0044] The moisture-wicking and venting zone 3 includes a first moisture-wicking channel and a second moisture-wicking channel. The first moisture-wicking channel is formed using a third yarn, preferably a regenerated cellulose fiber or a hydrophilic modified polyester fiber with high hydrophilicity; the second moisture-wicking channel is formed using a fourth yarn, preferably a polyester fiber or nylon fiber with controlled hydrophilicity. The third and fourth yarns alternately loop within the moisture-wicking and venting zone 3, causing the first and second moisture-wicking channels to alternately arrange themselves in the fabric plane.

[0045] In this embodiment, the equivalent capillary radius of the first moisture-wicking channel is controlled to be 15–40 μm, and the equivalent capillary radius of the second moisture-wicking channel is controlled to be 40–80 μm. Because the two channels have different capillary sizes and yarn surface wetting characteristics, after liquid enters the moisture-wicking and venting zone 3, it is first rapidly absorbed through the first moisture-wicking channel, and then diffuses laterally within the adjacent second moisture-wicking channel, thereby preventing sweat from concentrating in a single location. Along the direction from the moisture-sensitive deformation zone 2 to the stable braiding zone 1, the coil spacing of the moisture-wicking and venting zone 3 gradually increases, for example, from 1.2–1.6 mm to 2.0–3.0 mm, thus gradually increasing the diffusion area corresponding to the liquid migration process.

[0046] Therefore, in this embodiment, the following continuous structural relationship is formed: the outer stable knitting area 1 is connected to the inner moisture-sensitive deformation area 2 through transition coils 4; the moisture-sensitive deformation area 2 is connected to the inner end of the moisture-conducting and venting area 3 through a moisture-conducting connecting coil; the outer end of the moisture-conducting and venting area 3 is connected to the outer stable knitting area 1 through another set of transition coils. All three are directly formed by knitting coils, without using adhesives, stitching, or other attachments. This forms a continuous planar structure of "stable knitting area 1—moisture-sensitive deformation area 2—moisture-conducting and venting area 3—stable knitting area 1".

[0047] Based on the above structure, this embodiment further employs a differential tension knitting process to form the initial stress state of the moisture-sensitive deformation zone 2. Specifically, when knitting using an electronic knitting machine with 32-36 needles / inch, the feeding tension of the second yarn is controlled at 8-12 cN, and the feeding tension of the first yarn is controlled at 10-15 cN, making the feeding tension of the first yarn 1.10-1.40 times that of the second yarn. By controlling the feeding lengths of the two yarns, a difference of 0.10-0.35 mm is created between the loop lengths of the first and second yarns after looping, thereby pre-forming a deformation difference that can be activated by humidity within the moisture-sensitive deformation zone 2.

[0048] After the integrated weaving of the moisture-sensitive deformation zone 2 and the moisture-wicking and venting zone 3 is completed, the fabric undergoes phased heat setting. The first phase involves a temperature treatment of 80–110°C for 30–120 seconds to release some of the residual stress generated during knitting. The second phase involves a temperature treatment of 120–160°C for 20–90 seconds to fix the loop structure of the stabilizing weaving zone 1, the transition loop 4, and the moisture-wicking and venting zone 3, while preserving the difference in moisture absorption deformation between the first and second yarns. For a combination of polyester stabilizing yarn and regenerated cellulose high-twist yarn, this embodiment preferably uses a first phase treatment at 95°C for 60 seconds and a second phase treatment at 135°C for 45 seconds.

[0049] After heat setting, the fabric is calibrated for humidity response. First, the sample is equilibrated at 20-25℃ and 40-50% relative humidity for 24 hours to obtain a moisture-sensitive deformation pore image in the dry state, and the average effective pore area A0 is obtained by microscopic image analysis. Then, the same sample is placed in an environment with a relative humidity of 85%±3% for 30 minutes for equilibration, or artificial sweat equivalent to 0.5-1.0 mL / cm² is applied to the moisture-sensitive deformation area 2 to allow the first yarn to fully absorb moisture, and the effective pore area A1 in the moisture-absorbing state is obtained.

[0050] The dynamic porosity increase η is calculated according to the following formula: η=(A1-A0) / A0×100%.

[0051] When η is less than 20%, it indicates that the deformation difference between the first yarn and the second yarn is insufficient. In this case, increase the feeding tension difference between the first yarn and the second yarn by 0.5 to 2.0 cN, or reduce the heat setting temperature of the first stage by 3 to 8°C, so that the first yarn can retain greater wet shrinkage capacity. When η is greater than 100%, reduce the feeding tension difference between the first yarn and the second yarn by 0.5 to 2.0 cN, or increase the heat setting temperature of the first stage by 3 to 8°C, so as to reduce the excessive opening of the moisture-sensitive deformation zone 2.

[0052] Through the above calibration, the dynamic porosity increase η of the moisture-sensitive deformation zone 2 is controlled within the range of 20% to 100%. In the preferred embodiment, η is controlled within the range of 35% to 75%, thereby balancing the lightness and thinness in the dry state, the stability of the fabric appearance, and the dynamic air permeability in the moisture-absorbing state.

[0053] The knitted fabric produced in this embodiment has a thickness controlled at 0.35–0.65 mm and a weight controlled at 95–150 g / m². The stabilizing knitting zone 1 provides the main strength and dimensional stability of the fabric, the moisture-sensitive deformation zone 2 generates humidity-responsive dynamic openings, and the moisture-wicking and venting zone 3 diffuses liquid and moisture from the moisture-sensitive deformation zone 2 to the periphery. Since all three are integrally formed from the same knitted layer, the fabric thickness is not significantly increased by adding separate breathable or moisture-wicking layers.

[0054] Furthermore, when the human body is in a dry environment or does not sweat profusely, the first yarn is in a low-moisture state, the length difference between the first and second yarns remains at a low level, and the moisture-sensitive deformation holes maintain a small aperture, keeping the fabric flat and lightweight. When human movement causes increased sweating, the sweat first enters the moisture-sensitive deformation zone 2. The first yarn absorbs moisture and undergoes wet shrinkage, causing the differential moisture-absorbing deformation coils to undergo directional displacement, thus actively expanding the moisture-sensitive deformation holes. The expanded moisture-sensitive deformation holes simultaneously become air exchange inlets and connect with the adjacent moisture-guiding and exhaust zones 3. The sweat migrates to the periphery through the first and second moisture-guiding channels, forming a continuous process of "moisture absorption—deformation—opening—moisture ducting—diffusion".

[0055] When human activity ceases and the fabric moisture content decreases, the first yarn gradually returns to its initial size. Simultaneously, the elastic recovery yarn in the transition coil 4 generates a restoring force, causing the differential moisture-absorbing deformation coil to gradually return to its initial position, and the moisture-sensitive deformation hole shrinks again. Therefore, the dynamic opening process can be reversibly adjusted according to changes in the fabric's moisture content, rather than a one-time permanent pore enlargement.

[0056] In this embodiment, the specific materials of the first, second, third, and fourth yarns are not limited to the materials mentioned above, as long as they can respectively achieve the functions of poor moisture absorption deformation, dimensional stability, rapid moisture absorption, and moisture diffusion and wicking. The area ratio, loop density, yarn linear density, feeding tension, and heat setting parameters of the stable knitting zone 1, the moisture-sensitive deformation zone 2, and the moisture-wicking and venting zone 3 can also be adjusted according to the knitting equipment model and end use, but the deformation difference between the moisture-sensitive deformation zone 2 and the stable knitting zone 1, as well as the connection relationship between the moisture-sensitive deformation zone 2 and the moisture-wicking and venting zone 3, should be maintained.

[0057] Through the above implementation method, the lightweight knitted fabric in this embodiment does not simply rely on reducing the fabric density or increasing the number of pores to improve breathability. Instead, it utilizes the difference in moisture absorption deformation between the first yarn and the second yarn to create directional dynamic openings in the moisture-sensitive deformation zone 2 under the boundary constraint of the stable knitting zone 1. Furthermore, the moisture-wicking and venting zone 3, which is woven integrally with it, diffuses sweat and moisture to the outside, thereby achieving dynamic breathability and moisture wicking effect that automatically adjusts with changes in humidity while maintaining the lightweight nature of the fabric.

Claims

1. A lightweight and highly breathable knitted fabric, comprising a fabric body, wherein the fabric body is a single-layer knitted structure formed by knitting multiple yarns together, and the fabric body forms a stable knitting area, at least one moisture-sensitive deformation area and at least one moisture-wicking and venting area along its planar direction. The stabilizing weaving zone is located on the periphery of the fabric body and is used to form the main support structure of the fabric body; The moisture-sensitive deformation zone is located within the area enclosed by the stable braiding zone and is integrally braided and connected by the transition coil between the stable braiding zone and the moisture-sensitive deformation zone. The moisture-sensitive deformation zone is formed by alternating loops of the first yarn and the second yarn to create differential moisture-absorbing deformation coils. The moisture absorption deformation rate of the first yarn is greater than that of the second yarn, so that the differential moisture-absorbing deformation coils will undergo directional deformation after absorbing moisture. The moisture-conducting and exhaust zone extends from the moisture-sensitive deformation zone toward the stable braiding zone and is arranged adjacent to the moisture-sensitive deformation zone; the inner end of the moisture-conducting and exhaust zone is integrally braided and connected to the moisture-sensitive deformation zone through a moisture-conducting connecting coil, and the outer end of the moisture-conducting and exhaust zone is integrally braided and connected to the stable braiding zone through an outer transition coil, so as to form a continuous moisture-conducting and exhaust path extending from the moisture-sensitive deformation zone to the stable braiding zone. When the moisture-sensitive deformation zone absorbs moisture, the difference in moisture absorption deformation between the first yarn and the second yarn drives the differential moisture absorption deformation coil to shift in a predetermined direction, thereby increasing the effective pore area between adjacent differential moisture absorption deformation coils and connecting the increased effective pores with the moisture-conducting and exhaust zone to form a ventilation and moisture-removing path that is synchronously enhanced when humidity increases.

2. The lightweight and highly breathable knitted fabric according to claim 1, characterized in that: The first yarn is a moisture-absorbing deformable yarn that shrinks axially after absorbing moisture, and the second yarn is a dimensionally stable yarn whose dimensional change rate after absorbing moisture is lower than that of the first yarn. The difference between the moisture absorption deformation rates of the first yarn and the second yarn is 2% to 12%.

3. The lightweight and highly breathable knitted fabric according to claim 1, characterized in that: The moisture-sensitive deformation zone includes a first coil unit arranged along a first direction and a second coil unit arranged along a second direction. The first coil unit is formed by a first yarn, and the second coil unit is formed by a second yarn. The first coil unit and the second coil unit are alternately connected to form a plurality of moisture-sensitive deformation holes. The moisture-sensitive deformable pore has a first equivalent pore size in a dry state and a second equivalent pore size in a moisture-absorbing state, wherein the second equivalent pore size is 1.2 to 2.5 times the first equivalent pore size.

4. The lightweight and highly breathable knitted fabric according to claim 1, characterized in that: The transition coil is formed of elastic recovery yarn and is used to limit the deformation of the moisture-sensitive deformation zone in a non-predetermined direction; another set of transition coils is used to continuously connect the moisture-conducting and venting zone with the peripheral stable braiding zone.

5. The lightweight and highly breathable knitted fabric according to claim 1, characterized in that: The moisture-guiding and exhaust zone includes a first moisture-guiding channel and a second moisture-guiding channel extending along the humidity migration direction. The first moisture-guiding channel is formed by a third yarn, and the second moisture-guiding channel is formed by a fourth yarn. The third yarn has higher hydrophilicity than the fourth yarn, and the equivalent capillary radius of the first moisture-conducting channel is smaller than that of the second moisture-conducting channel, so that after the liquid enters the moisture-conducting and exhausting zone from the moisture-sensitive deformation zone, a gradient migration is formed between different capillary channels.

6. The lightweight and highly breathable knitted fabric according to claim 5, characterized in that: The first and second moisture-conducting channels are alternately arranged along the humidity migration direction, and the coil spacing of the moisture-conducting exhaust zone gradually increases along the humidity migration direction, so that a gradually expanding diffusion area is formed during the migration of liquid from the moisture-sensitive deformation zone to the stable braiding zone. The moisture-wicking and exhaust zone has at least one inner end that communicates with the moisture-sensitive deformation hole of the moisture-sensitive deformation zone and one outer end that communicates with the stable braiding zone.

7. The lightweight and highly breathable knitted fabric according to claim 1, characterized in that: The moisture-sensitive deformation zone accounts for 15% to 45% of the fabric body area, the moisture-wicking and exhaust zone accounts for 10% to 30% of the fabric body area, and the remaining area is the stable weaving zone. The fabric body has a thickness of 0.25 to 0.80 mm and a weight of 80 to 180 g / m², and the effective pore area of ​​the fabric body in the hygroscopic state increases by 20% to 100% compared with the dry state.

8. A method for preparing a lightweight, highly breathable knitted fabric as described in any one of claims 1 to 7, characterized in that: S1. Yarn pretreatment: Tension homogenization treatment is performed on the first yarn, the second yarn, the third yarn, the fourth yarn and the elastic recovery yarn respectively, and the first yarn is subjected to pre-moisture absorption-drying cycle treatment to stabilize the moisture absorption deformation response of the first yarn. S2. Outer skeleton weaving: A stable weaving area is formed by weaving with dimensionally stable yarns, and weaving positions for a moisture-sensitive deformation area and a moisture-wicking and exhaust area are reserved inside the stable weaving area; S3, Moisture-sensitive area weaving: The first yarn and the second yarn are fed alternately according to the preset yarn feeding tension difference to form differential moisture-absorbing deformation coils inside the stable weaving area, and the moisture-sensitive deformation area and the stable weaving area are connected as one through the transition coil. S4, Moisture-guiding area weaving: The third and fourth yarns are alternately looped along the direction from the moisture-sensitive deformation zone to the stable weaving zone, so that one end of the moisture-guiding and exhaust zone is connected to the moisture-sensitive deformation zone through the moisture-guiding connecting coil, and the other end is connected to the stable weaving zone through the outer transition coil; S5. Pre-strain setting: The fabric formed by the integral weaving is heat-set in stages, so that the difference in moisture absorption deformation between the first yarn and the second yarn is locked in the moisture-sensitive deformation zone, and the moisture-conducting channels in the moisture-conducting and exhaust zone maintain the predetermined capillary structure. S6. Humidity Response Calibration: The effective pore area of ​​the fabric is detected in both dry and hygroscopic states. Based on the detection results, the feeding tension difference between the first and second yarns and the heat setting parameters are adjusted to achieve the predetermined dynamic air permeability enhancement effect in the moisture-sensitive deformation zone.

9. The method for preparing a lightweight and highly breathable knitted fabric according to claim 8, characterized in that: In step S3, the feeding tension of the first yarn is 1.10 to 1.40 times that of the second yarn, and by controlling the difference in the feeding amount of the first yarn and the second yarn, the moisture-sensitive deformation zone forms a preset initial coil spacing. Step S5 includes a first stage of stress relief shaping and a second stage of structural locking shaping. The first stage heat setting temperature is 80-110℃ and the processing time is 30-120s. The second stage heat setting temperature is 120-160℃ and the processing time is 20-90s.

10. The method for preparing a lightweight and highly breathable knitted fabric according to claim 8, characterized in that: In step S6, the effective pore area A0 of the fabric in its dry state and the effective pore area A1 in its moisture-absorbing state are obtained, and the dynamic pore increase η is calculated: η = (A1 - A0) / A0 × 100%; When η < 20%, increase the feeding tension difference between the first yarn and the second yarn and / or decrease the heat setting temperature of the first stage; when η > 100%, decrease the feeding tension difference and / or increase the heat setting temperature of the first stage, so that the dynamic porosity increase η is controlled within the range of 20% to 100%, thereby obtaining a humidity-responsive knitted fabric with active increase in effective porosity after moisture absorption.

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