Production method of breathable fabric for underwear and disposable underwear

Abstract

The present invention belongs to the technical field of breathable fabric production for underwear, and proposes a method for producing breathable fabric for underwear and disposable underwear, the method comprising the following steps: stretching an elastic surface to a preset length, obtaining the stress of the elastic surface when the elastic surface is stretched to the preset length, and calculating the average load stress of the elastic surface according to the stress of the elastic surface; obtaining the stress distribution of the elastic surface after shearing; obtaining the force-trapped vulnerable area of ​​the elastic surface after shearing through the average load stress of the elastic surface; hot-pressing and bonding an elastic supplementary surface with a thickness equal to the thickness difference to the force-trapped vulnerable area of ​​the elastic surface after shearing to obtain a hot-pressed elastic surface; and obtaining the fabric of disposable underwear. The embodiment of the present invention can improve the comfort and service life of disposable underwear by finely adjusting the force-trapped vulnerable area during the production process.

Description

Technical Field

[0001] The invention belongs to the technical field of production of breathable fabrics for underwear, and in particular relates to a production method of breathable fabrics for underwear and disposable underwear. Background Art

[0002] The Chinese patent with publication number CN114290762A discloses "An antibacterial breathable fabric for underwear and production method". The antibacterial breathable fabric for underwear produced by this method has good air permeability and moisture permeability and is not easy to breed bacteria. However, this method does not add elastic materials, which leads to the lack of necessary elasticity in the underwear during wearing, affecting the comfort and fit.

[0003] To solve this problem, elastic materials such as spandex or lycra can be added during the production of antibacterial and breathable fabrics. This elastic material can significantly improve the elasticity and fit of underwear, making it more in line with human body curves and providing a better wearing experience. However, after adding elastic materials, stress concentration problems will occur when the fabric is stretched and bent. Stress concentration will cause certain areas of the fabric to be subjected to excessive stress, thus affecting the durability of the underwear, and making it prone to wear and tear problems, which in turn affects the product's service life and user experience. Summary of the invention

[0004] The present invention aims to solve at least one of the technical problems in the related art to a certain extent. To this end, the first purpose of the present invention is to propose a method for producing breathable fabrics for underwear, which can improve the comfort and service life of disposable underwear by finely adjusting the stress-trapped vulnerable areas during the production process; avoid the problem of material wear or tear caused by stress concentration, and ensure the stability and durability of disposable underwear during wearing.

[0005] A second object of the present invention is to provide disposable underwear.

[0006] To achieve the above-mentioned purpose, the first embodiment of the present invention provides a method for producing a breathable fabric for underwear, wherein the breathable fabric for underwear comprises: a first outer layer sheet, an elastic surface, and a second outer layer sheet, wherein the first outer layer sheet is a waterproof breathable non-woven fabric and an antibacterial shielding non-woven fabric, and the second outer layer sheet is a moisture-absorbing non-woven fabric and a soft non-woven fabric, and the method comprises the following steps:

[0007] S100, stretching the elastic surface to a preset length, obtaining the stress of the elastic surface when the elastic surface is stretched to the preset length, and calculating the average load stress of the elastic surface according to the stress of the elastic surface;

[0008] S200, shearing the elastic surface and obtaining the stress distribution of the elastic surface after shearing; obtaining the force-trapped vulnerable area of ​​the elastic surface after shearing through the average load stress of the elastic surface, and calculating the thickness difference that needs to be adjusted in the force-trapped vulnerable area;

[0009] S300, hot-pressing and bonding the elastic supplementary surface having a thickness equal to the thickness difference to the force-trapped vulnerable region of the sheared elastic surface to obtain a hot-pressed elastic surface;

[0010] S400, heat-pressing and bonding the first outer layer sheet, the heat-pressed elastic surface and the second outer layer sheet to obtain a fabric of disposable underwear.

[0011] According to the production method of the embodiment of the present invention, the comfort and service life of disposable underwear can be improved by finely adjusting the stress-trapped vulnerable areas during the production process; material wear or tear problems caused by stress concentration can be avoided, thereby ensuring the stability and durability of the disposable underwear during wearing.

[0012] Among them, the structures and manufacturing processes of waterproof and breathable non-woven fabrics, antibacterial shielding non-woven fabrics, hygroscopic non-woven fabrics and soft non-woven fabrics are as follows: Among them, the manufacturing method of waterproof and breathable non-woven fabrics is: using melt-extruded polymer particles, blowing them into fibers through high-speed airflow, and then solidifying them through hot rollers or chemical treatment to form non-woven fabrics, and then adding additives; the manufacturing method of antibacterial shielding non-woven fabrics is: fixing the fibers together through chemical adhesives to form fabrics, and adding antibacterial agents or shielding agents during the manufacturing process; the manufacturing method of hygroscopic non-woven fabrics is: using water as a medium, suspending the fibers in water, collecting them through a mesh belt or a roller to form fabrics; the manufacturing method of soft non-woven fabrics is: mechanically winding and interweaving the fiber layers through a needle punching machine to form a tightly structured but soft fabric.

[0013] Optionally, the first outer layer is a waterproof and breathable fabric layer and an antibacterial shielding fabric layer, and the second outer layer is a hygroscopic fabric layer and a soft fabric layer, wherein the structures and manufacturing process of the waterproof and breathable fabric layer, the antibacterial shielding fabric layer, the hygroscopic fabric layer and the soft fabric layer are as follows:

[0014] The waterproof and breathable fabric layer is blended with polyolefin fibers, polyester fibers and polyurethane fibers in a mass ratio of 5:4:1. It has high hydrophobicity and excellent resilience, is suitable for use in the medical and health fields, has significant waterproof effects and is easy to clean; the antibacterial shielding fabric layer is blended with bamboo charcoal fibers, silver-plated fibers, glass fibers and honeysuckle fibers in a mass ratio of 10:1:3:6. It has comprehensive properties such as antibacterial, antistatic, radiation protection, moisture absorption and breathability, and is suitable for making high-performance underwear fabrics; the moisture-absorbing fabric layer is composed of a polymer water-absorbing and breathable layer, a water-absorbing cotton core layer and a guide layer. Through the combination of the polymer water-absorbing and breathable layer and the water-absorbing cotton core layer, it effectively absorbs and locks body fluids to keep dry and comfortable; the soft fabric layer is blended with soybean protein fibers, Tencel fibers and polyester microfibers in a mass ratio of 5:4:1. It has a soft and comfortable feel and good thermal insulation performance, and is suitable as the contact layer of underwear.

[0015] Furthermore, in step S100, the device for stretching the elastic surface to a preset length is a tensile testing machine, which is equipped with a three-dimensional scanner and a stress detector; wherein the elastic surface is a combination of one or more elastic fibers (such as spandex or Lycra), elastic fabrics, elastic foams or foam materials.

[0016] Furthermore, the method for obtaining the stress of the elastic surface when it is stretched to a preset length includes: obtaining a three-dimensional model of the elastic surface by scanning with a three-dimensional scanner, and obtaining the stress of the elastic surface with a stress detector, and adding the distribution and data of the stress of the elastic surface to the three-dimensional model of the elastic surface, and adding the thickness data of the elastic surface to the three-dimensional model of the elastic surface.

[0017] S101, dividing the three-dimensional model of the elastic surface into regions by using a loop subdivision algorithm;

[0018] Specifically, the three-dimensional model of the elastic surface is subdivided [3, 9] times by the loop subdivision algorithm, and the three-dimensional model of the elastic surface is subdivided into K sub-regions, and S1={s1(i)} represents the set of sub-regions of the three-dimensional model of the elastic surface, s1(i) represents the i-th sub-region, i∈[1,K], and the three-dimensional model of the elastic surface is further meshed using the free meshing algorithm to obtain the divided three-dimensional model of the elastic surface;

[0019] Since the stress concentration area of ​​the elastic surface may cause the elasticity or comfort of the area to decrease after the disposable underwear is made, and if the stress concentration causes the material in some areas to be subjected to greater stress, it will greatly affect the durability and service life of the disposable underwear, and it will be more prone to wear or tear, resulting in its inability to be used normally. In order to solve this problem, it is necessary to determine the average stress of the elastic surface under the preset tensile state, and perform a prestressed constant load effect analysis on the elastic surface based on the average stress. Based on the analysis results, the stress concentration area is filled with material to improve the durability of the disposable underwear.

[0020] S102, calculate the uniform load stress of the elastic surface;

[0021] Furthermore, the method for calculating the average load stress of the elastic surface is: obtaining the stress value of each grid in the three-dimensional model of the divided elastic surface; wherein the stress value of the grid is the average stress value of all pixel points in the grid;

[0022] Specifically, the number of grids in s1(i) is obtained as G, and a(i, j) is used to represent the stress value in the grid with sequence number j in s1(i), j∈[1,G]. The maximum stress value in each grid in s1(i) is calculated and recorded as the easy-to-fall stress value am(i), and the median ag(i) of the stress value in each grid in s1(i) is obtained; the average load stress UIS(i) of s1(i) is calculated by the first equation.

[0023] Among them, the first equation is: ;

[0024] Where a(i, j) is the stress value of the jth grid in the i-th sub-region, which represents the stress in the grid caused by the prestressing operation of stretching the elastic surface to a preset length. G is the number of grids in the i-th sub-region, which represents the number of grids in the s1(i) region. ag(i) is the median of the stress values ​​of all grids in the sub-region s1(i), which represents the optimal stress level in the ideal case in the sub-region s1(i). The thermal stress values ​​of all grids in the sub-region s1(i) are summed, which represents the sum of the stress values ​​in the sub-region s1(i). It is a ratio of the typical stress (median stress value) in the sub-region s1(i) to the overall stress accumulation in the region, and is used to measure the uniformity of stress distribution in the sub-region s1(i). If the ratio of the median stress value ag(i) to the overall stress accumulation is high, it indicates that the stress in the region is large, and the median stress value contributes greatly to the overall stress, and there may be stress concentration. If the ratio is low, it indicates that the median stress value contributes less to the overall stress, and the stress in the region is relatively small.

[0025] Among them, average load stress refers to the average stress value calculated after the stress distribution of each grid under a preset tensile state in a specific area or sub-area of ​​the elastic fabric. It is the result obtained by weighted averaging the stress of all grids in each area when the fabric is stretched to a preset length. It can help determine the average stress of the elastic fabric under a preset tensile state.

[0026] The beneficial effects of this step are as follows: using the loop subdivision algorithm and the free meshing algorithm, the three-dimensional model of the elastic surface is subdivided into multiple sub-regions and grids, which can analyze the stress distribution more finely and accurately; and further through regional division, stress analysis can be carried out on a smaller scale, which can better discover and solve the problem of subtle stress concentration leading to easy tearing in subsequent use; and by calculating the stress value of each grid and its median and maximum value, it is helpful to identify anomalies and extreme conditions in the stress distribution. These values ​​provide key data support for subsequent thickness adjustment and supplementation, ensuring the accuracy and effectiveness of the adjustment; by summing the stress values ​​of all grids in the sub-region to obtain the sum of the stress in the sub-region, it can reflect the overall stress condition of the region under the prestressed state, so that the average load stress provides a basis for identifying and adjusting the force-trapped vulnerable area, making the subsequent adjustment of the fabric more scientific and reasonable; through these steps and the calculation of the average load stress, the breathable fabric for underwear produced has significantly improved comfort and durability.

[0027] S103, traversing the sub-regions of the three-dimensional model of each elastic surface in turn, and obtaining the maximum average load stress of the divided three-dimensional model of the elastic surface;

[0028] Specifically, the average load stress of each sub-region is obtained by the first equation, the average load stress of each sub-region is compared, and the maximum average load stress among the average load stresses of each sub-region is recorded as UISM.

[0029] In step S200, the elastic surface is sheared and the stress distribution of the elastic surface after shearing is obtained; the force-trapped vulnerable area of ​​the elastic surface after shearing is obtained through the average load stress of the elastic surface, and the thickness difference that needs to be adjusted in the force-trapped vulnerable area is calculated, including:

[0030] Specifically, shearing the elastic surface and obtaining the stress distribution of the elastic surface after shearing includes: determining the appropriate shearing mode and size according to the design requirements and the characteristics of the fabric; wherein the shearing mode includes: a combination of one or more of straight-line cutting, curve cutting or cutting of a specific shape; then shearing the elastic fabric according to the design requirements and mode, ensuring that the elastic fabric is not damaged or distorted during the cutting process to maintain its structural integrity, and finally obtaining the stress of the elastic surface after shearing with a stress detector, and adding the stress distribution and data of the elastic surface to the three-dimensional model of the divided elastic surface, and recording it as the three-dimensional model of the elastic surface after shearing. Let b(i, j) represent the stress value in the grid with sequence number j in s1(i) of the elastic surface after shearing;

[0031] Furthermore, the method of obtaining the force-trapped vulnerable area of ​​the elastic surface after shearing by using the average load stress of the elastic surface includes:

[0032] S201, a sub-region in which all stresses in the three-dimensional model of the sheared elastic surface are greater than the maximum average load stress is recorded as a force-trapped vulnerable region, and the sequence number of the force-trapped vulnerable region is extracted and recorded as z, where z is the sequence number of the force-trapped vulnerable region.

[0033] S202, taking the average thickness value of all grids in the vulnerable area of ​​the force trap and recording it as the original average thickness value UC(z);

[0034] S203, calculating the thickness difference UX(z) that needs to be adjusted in the vulnerable area of ​​the force trap;

[0035] Specifically, the average load stress of each sub-region of the three-dimensional model of the elastic surface is formed into a sequence as a write sequence Ust; the average value RK of the ratio between all the average load stresses and UISM in Ust is calculated, that is:

[0036] ;

[0037] The thickness difference UX(z) that needs to be adjusted is the original average thickness value UC(z) multiplied by F, where F is the absolute value of 1 minus RK divided by e; where e is the base of the natural constant. By dividing by e, the amplitude of the thickness adjustment can be controlled to make the thickness difference UX(z) smoother and more stable, avoiding excessive adjustments due to changes in the stress ratio RK, thereby ensuring that the material has good functionality and consistency during use.

[0038] The beneficial effects of this step are: by analyzing the stress distribution and thickness data of the force-trap vulnerable area, the thickness difference that needs to be adjusted in each area can be accurately determined. This accuracy ensures that when processing elastic fabrics, necessary corrections and adjustments can be made in a targeted manner to improve the quality and performance of disposable underwear; based on the calculated thickness difference, the production process can adjust the material or process parameters in a targeted manner, such as the pressure and temperature settings during the hot pressing bonding process, to ensure that the elastic fabric in the force-trap vulnerable area can achieve the stability and durability required by the design; by making adjustments to the force-trap vulnerable area during the design stage, the changes or unevenness in the production process of disposable underwear can be reduced. This helps to improve the overall consistency and quality stability of disposable underwear, thereby reducing quality problems and customer complaints caused by production differences; by accurately calculating and adjusting the thickness difference of the force-trap vulnerable area, unnecessary material waste or repeated processing can be avoided, thereby reducing production costs and improving production efficiency to a certain extent;

[0039] Since the calculation method of the thickness difference UX(z) that needs to be adjusted mainly relies on the maximum average load stress as the basis for adjusting the thickness, although it can reduce production costs and improve production efficiency to a certain extent, this method cannot fully consider the subtle differences in stress distribution in different areas of the elastic fabric, which may lead to excessive thickness adjustment in some areas, and simply adjusting based on the maximum stress value may result in the use of too much material in the vulnerable area, causing the underwear to be uneven and affecting the wearing experience. In order to solve the above problems, the following preferred methods are proposed:

[0040] Preferably, the thickness difference UX(z) of the vulnerable area to be adjusted is calculated as follows: for each sub-area i, i∈[1,K], calculate its regional logarithmic difference UFG(i)=|UIS(i)+UISM-ag(i)|÷(am(i)×e), where e is the base of the natural constant, || is the absolute value, UIS(i) is the average load stress of s1(i), UISM is the maximum average load stress, am(i) represents the vulnerable stress value in each grid of s1(i), and ag(i) is the average load stress value of each grid of s1(i). The median of the stress values ​​in ; the regional logarithmic differences of all sub-regions are added and divided by K to obtain the effective logarithmic mean difference β, then the adjusted thickness difference UX(z) is the original thickness value UC(z) multiplied by the effective logarithmic mean difference β, wherein the operation of multiplying by the natural constant e can perform a certain curve data recovery on the result after reducing the adjustment range, so as to ensure that the calculation result of the effective logarithmic mean difference β is within a reasonable range, so as to achieve the stability and sensitivity of the balanced adjustment, so that the final adjusted thickness difference is neither excessive nor can accurately reflect the actual situation of stress distribution.

[0041] The beneficial effects of this step are: by introducing the mean difference of the effective logarithm β and comprehensively considering the stress distribution characteristics of each sub-region of the elastic fabric, the overall stress state can be more comprehensively understood and analyzed, avoiding the limitations of a single indicator, and the mean difference of the effective logarithm β can more accurately reflect the overall trend of the stress values ​​within each sub-region by cumulatively considering the regional logarithmic difference. Compared with simply adjusting according to the maximum stress value, this method can more effectively guide the implementation of thickness adjustment, thereby improving the calculation accuracy; because the calculation is more accurate and comprehensive, the optimization method can more quickly determine the appropriate thickness adjustment strategy at the beginning of production. This can reduce the extension of the production cycle and the waste of resources caused by experiments and repeated adjustments, improve production efficiency and the quality stability of disposable underwear, thereby further optimizing resource utilization efficiency and reducing production costs.

[0042] Furthermore, the calculated thickness difference can ensure that the elastic supplementary surface has sufficient thickness and layers at the stress concentration site, thereby reducing deformation and breakage caused by stress concentration caused by stretching or other external forces, thereby improving the quality stability and consistency of disposable underwear.

[0043] S300, hot-pressing and bonding the elastic supplementary surface having a thickness equal to the thickness difference to the force-trapped vulnerable region of the sheared elastic surface to obtain a hot-pressed elastic surface;

[0044] The material of the elastic supplementary surface is elastic fiber (such as spandex or Lycra), elastic fabric, elastic foam or a combination of one or more foam materials;

[0045] Specifically, the sheared original elastic surface is placed on a working platform, and a hot-pressing adhesive is coated on the surface of the force-trapped vulnerable area; the pre-cut elastic supplementary surface is placed on the force-trapped vulnerable area, and it is ensured that the surfaces of the two are in close contact, and a hot press is used to heat and pressurize the elastic supplementary surface and the sheared original elastic surface to promote full melting of the adhesive and ensure that the two are firmly bonded together; finally, the pressure and temperature are maintained for a certain period of time to ensure that the adhesive achieves the best bonding effect during the cooling and curing process.

[0046] Wherein, the adhesive comprises a hot melt adhesive film.

[0047] S400, heat-pressing and bonding the first outer layer sheet, the heat-pressed elastic surface and the second outer layer sheet to obtain a fabric of disposable underwear.

[0048] Specifically, the first outer layer is placed on a work platform to ensure that it is flat and stable, and a hot-pressed elastic surface that has been subjected to hot-pressing bonding is placed on it to align closely with the inner contact surface of the first outer layer. The second outer layer is then placed on the hot-pressed elastic surface to ensure that its fabric matches that of the first outer layer. Using a hot press, appropriate heat and pressure are applied to the entire stacking structure to fully melt the adhesive and ensure that a strong bond is formed between each layer of fabric. Subsequently, the adhesive is solidified through an appropriate cooling time to ensure the stability and durability of the bond.

[0049] A second aspect of the present invention provides a disposable underwear, wherein the production process of the disposable underwear comprises:

[0050] On the flat breathable fabric, firstly, the first elastic band, the second elastic band or the shrink film are evenly laid; the role of the elastic band or the shrink film is to enhance elasticity to ensure that the underwear has a certain degree of comfort and stretchability; on the breathable fabric on which the elastic band or the shrink film has been laid, a layer of breathable fabric of the same size as the lower layer is covered in an aligned manner; then, the upper and lower layers of fabric are firmly bonded together using high-frequency welding, so that the elastic band or the shrink film is fixed between the two layers of breathable fabric, and the bonded breathable fabric is folded in half along the center line in the length direction, and after the folding, the fabric is laid flat to form a double-layer structure; heat sealing or ultrasonic composite technology is used to connect the two end edges of the breathable fabric together to form a ring body, which constitutes the basic shape of the underwear.

[0051] The breathable fabric is manufactured by the method for producing breathable fabric for underwear proposed in the embodiment of the first aspect of the present invention.

[0052] The beneficial effects of the present invention are as follows: by finely adjusting the stress-trapped vulnerable areas during the production process, the comfort and service life of disposable underwear can be effectively improved; material wear or tear problems caused by stress concentration can be avoided, ensuring the stability and durability of the disposable underwear during wearing. BRIEF DESCRIPTION OF THE DRAWINGS

[0053] Figure 1 Shown is a flow chart of a method for producing a breathable fabric for underwear. DETAILED DESCRIPTION

[0054] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present invention, and should not be construed as limiting the present invention.

[0055] Embodiment 1:

[0056] Figure 1Shown is a flow chart of a method for producing a breathable fabric for underwear.

[0057] Reference Figure 1 The present invention provides a method for producing a breathable fabric for underwear, the breathable fabric for underwear comprising: a first outer layer sheet, an elastic surface and a second outer layer sheet, wherein the first outer layer sheet is a waterproof breathable non-woven fabric and an antibacterial shielding non-woven fabric, and the second outer layer sheet is a moisture-absorbing non-woven fabric and a soft non-woven fabric, and the method comprises the following steps:

[0058] S100, stretching the elastic surface to a preset length, obtaining the stress of the elastic surface when the elastic surface is stretched to the preset length, and calculating the average load stress of the elastic surface according to the stress of the elastic surface;

[0059] S200, shearing the elastic surface and obtaining the stress distribution of the elastic surface after shearing; obtaining the force-trapped vulnerable area of ​​the elastic surface after shearing through the average load stress of the elastic surface, and calculating the thickness difference that needs to be adjusted in the force-trapped vulnerable area;

[0060] S300, hot-pressing and bonding the elastic supplementary surface having a thickness equal to the thickness difference to the force-trapped vulnerable region of the sheared elastic surface to obtain a hot-pressed elastic surface;

[0061] S400, heat-pressing and bonding the first outer layer sheet, the heat-pressed elastic surface and the second outer layer sheet to obtain a fabric of disposable underwear.

[0062] According to the production method of the embodiment of the present invention, the comfort and service life of disposable underwear can be improved by finely adjusting the stress-trapped vulnerable areas during the production process; material wear or tear problems caused by stress concentration can be avoided, thereby ensuring the stability and durability of the disposable underwear during wearing.

[0063] Among them, the structures and manufacturing processes of waterproof and breathable non-woven fabrics, antibacterial shielding non-woven fabrics, hygroscopic non-woven fabrics and soft non-woven fabrics are as follows: Among them, the manufacturing method of waterproof and breathable non-woven fabrics is: using melt-extruded polymer particles, blowing them into fibers through high-speed airflow, and then solidifying them through hot rollers or chemical treatment to form non-woven fabrics, and then adding additives; the manufacturing method of antibacterial shielding non-woven fabrics is: fixing the fibers together through chemical adhesives to form fabrics, and adding antibacterial agents or shielding agents during the manufacturing process; the manufacturing method of hygroscopic non-woven fabrics is: using water as a medium, suspending the fibers in water, collecting them through a mesh belt or a roller to form fabrics; the manufacturing method of soft non-woven fabrics is: mechanically winding and interweaving the fiber layers through a needle punching machine to form a tightly structured but soft fabric.

[0064] Furthermore, in step S100, the device for stretching the elastic surface to a preset length is a tensile testing machine, which is equipped with a three-dimensional scanner and a stress detector; wherein the initial length of the elastic surface is 100 mm, and during the stretching process, the preset length is set to 150 mm, and the material of the elastic surface is elastic fiber.

[0065] Furthermore, the method for obtaining the stress of the elastic surface when it is stretched to a preset length includes: obtaining a three-dimensional model of the elastic surface by scanning with a three-dimensional scanner, and obtaining the stress of the elastic surface with a stress detector, and adding the distribution and data of the stress of the elastic surface to the three-dimensional model of the elastic surface, and adding the thickness data of the elastic surface to the three-dimensional model of the elastic surface.

[0066] S101, dividing the three-dimensional model of the elastic surface into regions by using a loop subdivision algorithm;

[0067] Specifically, the three-dimensional model of the elastic surface is subdivided 8 times by the loop subdivision algorithm, and the three-dimensional model of the elastic surface is subdivided into K sub-regions, and S1={s1(i)} represents the set of sub-regions of the three-dimensional model of the elastic surface, s1(i) represents the i-th sub-region, i∈[1,K], and the three-dimensional model of the elastic surface is further meshed using the free meshing algorithm to obtain the divided three-dimensional model of the elastic surface;

[0068] Since the stress concentration area of ​​the elastic surface may cause the elasticity or comfort of the area to decrease after the disposable underwear is made, and if the stress concentration causes the material in some areas to be subjected to greater stress, it will greatly affect the durability and service life of the disposable underwear, and it will be more prone to wear or tear, resulting in its inability to be used normally. In order to solve this problem, it is necessary to determine the average stress of the elastic surface under the preset tensile state, and perform a prestressed constant load effect analysis on the elastic surface based on the average stress. Based on the analysis results, the stress concentration area is filled with material to improve the durability of the disposable underwear.

[0069] S102, calculate the uniform load stress of the elastic surface;

[0070] Furthermore, the method for calculating the average load stress of the elastic surface is: obtaining the stress value of each grid in the three-dimensional model of the divided elastic surface; wherein the stress value of the grid is the average stress value of all pixel points in the grid;

[0071] Specifically, the number of grids in s1(i) is obtained as G, and a(i, j) is used to represent the stress value in the grid with sequence number j in s1(i), j∈[1,G]. The maximum stress value in each grid in s1(i) is calculated and recorded as the easy-to-fall stress value am(i), and the median ag(i) of the stress value in each grid in s1(i) is obtained; the average load stress UIS(i) of s1(i) is calculated by the first equation.

[0072] Among them, the first equation is: ;

[0073] Where a(i, j) is the stress value of the jth grid in the i-th sub-region, which represents the stress in the grid caused by the prestressing operation of stretching the elastic surface to a preset length. G is the number of grids in the i-th sub-region, which represents the number of grids in the s1(i) region. ag(i) is the median of the stress values ​​of all grids in the sub-region s1(i), which represents the optimal stress level in the ideal case in the sub-region s1(i). The thermal stress values ​​of all grids in the sub-region s1(i) are summed, which represents the sum of the stress values ​​in the sub-region s1(i); It is a ratio of the typical stress (median stress value) in the sub-region s1(i) to the overall stress accumulation in the region, and is used to measure the uniformity of stress distribution in the sub-region s1(i). If the ratio of the median stress value ag(i) to the overall stress accumulation is high, it indicates that the stress in the region is large, and the median stress value contributes greatly to the overall stress, and there may be stress concentration. If the ratio is low, it indicates that the median stress value contributes less to the overall stress, and the stress in the region is relatively small.

[0074] Among them, average load stress refers to the average stress value calculated after the stress distribution of each grid under a preset tensile state in a specific area or sub-area of ​​the elastic fabric. It is the result obtained by weighted averaging the stress of all grids in each area when the fabric is stretched to a preset length. It can help determine the average stress of the elastic fabric under a preset tensile state.

[0075] The beneficial effects of this step are as follows: using the loop subdivision algorithm and the free meshing algorithm, the three-dimensional model of the elastic surface is subdivided into multiple sub-regions and grids, which can analyze the stress distribution more finely and accurately; and further through regional division, stress analysis can be carried out on a smaller scale, which can better discover and solve the problem of subtle stress concentration leading to easy tearing in subsequent use; and by calculating the stress value of each grid and its median and maximum value, it is helpful to identify anomalies and extreme conditions in the stress distribution. These values ​​provide key data support for subsequent thickness adjustment and supplementation, ensuring the accuracy and effectiveness of the adjustment; by summing the stress values ​​of all grids in the sub-region to obtain the sum of the stress in the sub-region, it can reflect the overall stress condition of the region under the prestressed state, so that the average load stress provides a basis for identifying and adjusting the force-trapped vulnerable area, making the subsequent adjustment of the fabric more scientific and reasonable; through these steps and the calculation of the average load stress, the breathable fabric for underwear produced has significantly improved comfort and durability.

[0076] S103, traversing the sub-regions of the three-dimensional model of each elastic surface in turn, and obtaining the maximum average load stress of the divided three-dimensional model of the elastic surface;

[0077] Specifically, the average load stress of each sub-region is obtained by the first equation, the average load stress of each sub-region is compared, and the maximum average load stress among the average load stresses of each sub-region is recorded as UISM;

[0078] S200, shearing the elastic surface and obtaining the stress distribution of the elastic surface after shearing; obtaining the force-trapped vulnerable area of ​​the elastic surface after shearing through the average load stress of the elastic surface, and calculating the thickness difference that needs to be adjusted in the force-trapped vulnerable area;

[0079] Specifically, shearing the elastic surface and obtaining the stress distribution of the elastic surface after shearing includes: determining the appropriate shearing mode and size according to the design requirements and the characteristics of the fabric; wherein the shearing mode includes: a combination of one or more of straight-line cutting, curve cutting or cutting of a specific shape; then shearing the elastic fabric according to the design requirements and mode, ensuring that the elastic fabric is not damaged or distorted during the cutting process to maintain its structural integrity, and finally obtaining the stress of the elastic surface after shearing with a stress detector, and adding the stress distribution and data of the elastic surface to the three-dimensional model of the divided elastic surface, and recording it as the three-dimensional model of the elastic surface after shearing. Let b(i, j) represent the stress value in the grid with sequence number j in s1(i) of the elastic surface after shearing;

[0080] Furthermore, the method of obtaining the force-trapped vulnerable area of ​​the elastic surface after shearing by using the average load stress of the elastic surface includes:

[0081] S201, a sub-region in which all stresses in the three-dimensional model of the sheared elastic surface are greater than the maximum average load stress is recorded as a force-trapped vulnerable region, and the sequence number of the force-trapped vulnerable region is extracted and recorded as z, where z is the sequence number of the force-trapped vulnerable region.

[0082] S202, taking the average thickness value of all grids in the vulnerable area of ​​the force trap and recording it as the original average thickness value UC(z);

[0083] S203, calculating the thickness difference UX(z) that needs to be adjusted in the vulnerable area of ​​the force trap;

[0084] The average load stress of each sub-region of the three-dimensional model of the elastic surface is composed of a sequence as the write sequence Ust; the average value RK of the ratios between all average load stresses and UISM in Ust is calculated, and the thickness difference UX(z) that needs to be adjusted is the original average thickness value UC(z) multiplied by F, where F is the absolute value of 1 minus RK divided by e; where e is the base of the natural constant. By dividing by e, the amplitude of the thickness adjustment can be controlled, making the thickness difference UX(z) smoother and more stable, avoiding excessive adjustments due to changes in the stress ratio RK, thereby ensuring that the material has good functionality and consistency during use.

[0085] The beneficial effects of this step are: by analyzing the stress distribution and thickness data of the force-trap vulnerable area, the thickness difference that needs to be adjusted in each area can be accurately determined. This accuracy ensures that when processing elastic fabrics, necessary corrections and adjustments can be made in a targeted manner to improve the quality and performance of disposable underwear; based on the calculated thickness difference, the production process can adjust the material or process parameters in a targeted manner, such as the pressure and temperature settings during the hot pressing bonding process, to ensure that the elastic fabric in the force-trap vulnerable area can achieve the stability and durability required by the design; by making adjustments to the force-trap vulnerable area during the design stage, the changes or unevenness in the production process of disposable underwear can be reduced. This helps to improve the overall consistency and quality stability of disposable underwear, thereby reducing quality problems and customer complaints caused by production differences; by accurately calculating and adjusting the thickness difference of the force-trap vulnerable area, unnecessary material waste or repeated processing can be avoided, thereby reducing production costs and improving production efficiency to a certain extent;

[0086] Since the calculation method of the thickness difference UX(z) that needs to be adjusted mainly relies on the maximum average load stress as the basis for adjusting the thickness, although it can reduce production costs and improve production efficiency to a certain extent, this method cannot fully consider the subtle differences in stress distribution in different areas of the elastic fabric, which may lead to excessive thickness adjustment in some areas, and simply adjusting based on the maximum stress value may result in the use of too much material in the vulnerable area, causing the underwear to be uneven and affecting the wearing experience. In order to solve the above problems, the following preferred methods are proposed:

[0087] Embodiment 2: Embodiment 2 replaces the calculation method of the thickness difference UX(z) of the vulnerable area that needs to be adjusted based on Embodiment 1. Specifically, for each sub-area i, i∈[1,K], calculate its regional logarithmic difference UFG(i)=|UIS(i)+UISM-ag(i)|÷(am(i)×e), where e is the base of the natural constant, || is the absolute value, UIS(i) is the average load stress of s1(i), UISM is the maximum average load stress, am(i) represents the vulnerable stress value in each grid of s1(i), ag( i) is the median of the stress values ​​in each grid of s1(i); the regional logarithmic differences of all sub-regions are added and divided by K to obtain the effective logarithmic mean difference β, and the adjusted thickness difference UX(z) is the original thickness value UC(z) multiplied by the effective logarithmic mean difference β; the operation of multiplying by the natural constant e can perform a certain curve data recovery on the result after reducing the adjustment range, so as to ensure that the calculation result of the effective logarithmic mean difference β is within a reasonable range, so as to achieve the stability and sensitivity of the balanced adjustment, so that the final adjusted thickness difference is neither excessive nor can accurately reflect the actual situation of stress distribution.

[0088] The beneficial effects of this step are: by introducing the mean difference of the effective logarithm β and comprehensively considering the stress distribution characteristics of each sub-region of the elastic fabric, the overall stress state can be more comprehensively understood and analyzed, avoiding the limitations of a single indicator, and the mean difference of the effective logarithm β can more accurately reflect the overall trend of the stress values ​​within each sub-region by cumulatively considering the regional logarithmic difference. Compared with simply adjusting according to the maximum stress value, this method can more effectively guide the implementation of thickness adjustment, thereby improving the calculation accuracy; because the calculation is more accurate and comprehensive, the optimization method can more quickly determine the appropriate thickness adjustment strategy at the beginning of production. This can reduce the extension of the production cycle and the waste of resources caused by experiments and repeated adjustments, improve production efficiency and the quality stability of disposable underwear, thereby further optimizing resource utilization efficiency and reducing production costs.

[0089] S300, hot-pressing and bonding the elastic supplementary surface having a thickness equal to the thickness difference to the force-trapped vulnerable region of the sheared elastic surface to obtain a hot-pressed elastic surface;

[0090] The material of the elastic supplementary surface is elastic fiber;

[0091] Specifically, the sheared original elastic surface is placed on a working platform, and a hot-pressing adhesive is coated on the surface of the force-trapped vulnerable area; the pre-cut elastic supplementary surface is placed on the force-trapped vulnerable area, and it is ensured that the surfaces of the two are in close contact, and a hot press is used to heat and pressurize the elastic supplementary surface and the sheared original elastic surface to promote full melting of the adhesive and ensure that the two are firmly bonded together; finally, the pressure and temperature are maintained for a certain period of time to ensure that the adhesive achieves the best bonding effect during the cooling and curing process.

[0092] Wherein, the adhesive comprises a hot melt adhesive film.

[0093] S400, heat-pressing and bonding the first outer layer sheet, the heat-pressed elastic surface and the second outer layer sheet to obtain a fabric of disposable underwear.

[0094] Specifically, the first outer layer is placed on a work platform to ensure that it is flat and stable, and a hot-pressed elastic surface that has been subjected to hot-pressing bonding is placed on it to align closely with the inner contact surface of the first outer layer. The second outer layer is then placed on the hot-pressed elastic surface to ensure that its fabric matches that of the first outer layer. Using a hot press, appropriate heat and pressure are applied to the entire stacking structure to fully melt the adhesive and ensure that a strong bond is formed between each layer of fabric. Subsequently, the adhesive is solidified through an appropriate cooling time to ensure the stability and durability of the bond.

[0095] The present invention also provides a disposable underwear, the production process of the disposable underwear comprising:

[0096] On the flat breathable fabric, the first elastic band, the second elastic band or the shrink film are evenly laid. The elastic band or the shrink film is used to enhance elasticity to ensure that the underwear has a certain degree of comfort and stretchability.

[0097] Next, a layer of breathable fabric of the same size as the lower layer is covered on the breathable fabric with the elastic band laid on it in an aligned manner; high-frequency welding is then used to firmly bond the upper and lower layers of fabric together, so that the elastic band or shrink film is fixed between the two layers of breathable fabric, and the bonded breathable fabric is folded in half along the center line in the length direction. After folding, the fabric is laid flat to form a double-layer structure; next, heat sealing or ultrasonic compounding technology is used to connect the two end edges of the breathable fabric together to form a ring, thus forming the basic shape of the underwear.

[0098] The breathable fabric is manufactured by the method for producing breathable fabric for underwear proposed in the embodiment of the first aspect of the present invention.

[0099] The disposable underwear made of the fabric produced by the above-mentioned method for producing breathable fabric for underwear is more comfortable and durable than the disposable underwear made by the production method proposed in "Antimicrobial breathable fabric for underwear and production method" disclosed in patent number CN114290762A.

[0100] Comparative Example 1

[0101] The disposable underwear is made by the production method proposed in the patent number CN114290762A "An antibacterial breathable fabric for underwear and production method", and the specific production method includes the following steps:

[0102] A. Manufacturing waterproof and breathable fabric layer: polyolefin fiber, polyester fiber and polyurethane fiber are respectively spun into yarn, and the three are blended into a waterproof and breathable fabric layer in a mass fraction ratio of 5:4:1, wherein the polyolefin fiber is used as the warp, and the polyester fiber and the polyurethane fiber are used as the composite weft;

[0103] B. Manufacturing the antibacterial shielding fabric layer: bamboo charcoal fiber, silver-plated fiber, glass fiber and honeysuckle fiber are respectively spun into silk, and the four are blended into the antibacterial shielding fabric layer in a mass fraction ratio of 10:1:3:6, wherein the bamboo charcoal fiber is used as the warp, and the silver-plated fiber, glass fiber and honeysuckle fiber are used as the composite weft;

[0104] C. Manufacturing a soft fabric layer: Soy protein fiber, Tencel fiber, and polyester microfiber are mixed in a mass fraction ratio of 5:4:1 to make silk, and then spun into a soft fabric layer;

[0105] D. Manufacturing the moisture-absorbing fabric layer: pressing the polymer water-absorbing breathable layer, the water-absorbing cotton core layer and the guide layer into the moisture-absorbing fabric layer;

[0106] E. Preparation of antibacterial and breathable fabrics: sew the antibacterial shielding fabric layer to the high molecular water-absorbing and breathable layer knitted by the hygroscopic fabric layer with metal sewing thread as the core layer of the antibacterial and breathable fabric; hot-press and bond the waterproof and breathable fabric layer to the antibacterial shielding fabric layer, and hot-press and bond the soft fabric layer to the guide layer of the hygroscopic fabric layer. The waterproof and breathable fabric layer and the soft fabric layer serve as the surface layer and the inner layer of the antibacterial and breathable fabric, respectively.

[0107] The production and preparation method of the silver-plated fiber in step B includes: using a vacuum ion plating machine, introducing argon gas of a certain pressure into a vacuum chamber, performing low-temperature plasma treatment on the polyethylene fiber line to improve the surface polarity of the fabric, and providing a weaving wire winding device in the vacuum chamber, the weaving wire winding device includes an upper weaving wire winding drum and a lower weaving wire winding drum, and the polyethylene fiber line is conveyed between the upper weaving wire winding drum and the lower weaving wire winding drum. The polyethylene fiber line is continuously vacuum sputtered with metallic silver in the vacuum chamber, and a layer of nano silver protective coating is coated on the surface of the silver-plated polyethylene fiber line, and the coating thickness is 0.015 to 0.02 μm.

[0108] When performing the low-temperature plasma treatment step, the plasma treatment temperature is 20-30°C; the vacuum degree is 60-95 Pa; the running speed of the polyethylene fiber line is 50-80 m / min; when performing the vacuum sputtering metallic silver step, the temperature at which silver ions are deposited on the surface of the polyethylene fiber line is 80-100°C; the vacuum degree is 0.15-0.4 Pa, and the running speed of the polyethylene fiber line is 3-5 m / min.

[0109] Experimental conditions:

[0110] To verify the advantages of disposable underwear made by the improved production method in terms of comfort and durability, the experimental subjects were 100 testers (50 men and 50 women), each of whom used one pair of ordinary disposable underwear and one pair of disposable underwear made by the improved method.

[0111] Experimental steps: 1. Prepare three sets of disposable underwear, one set is disposable underwear made by the method for producing a breathable fabric for underwear in Example 1 of the present invention, one set is disposable underwear made by the method for producing a breathable fabric for underwear in Example 2 of the present invention, and one set is a comparative example, which is a disposable underwear made by the production method proposed in "Antimicrobial breathable fabric for underwear and production method" disclosed in patent number CN114290762A. And use number identification to ensure that the tester cannot identify the type of underwear by appearance.

[0112] The experimental process includes: Wearing comfort test: the testers wear two types of disposable underwear respectively and record the wearing experience. The test content includes: subjective evaluation of comfort, breathability, moisture absorption, antibacterial properties, etc. Durability test: the testers wear the underwear for daily activities, including running, jumping, bending, etc., and record the durability of the underwear, such as wear, tear, and deformation.

[0113] The subjective evaluation data of the testers are collected through questionnaires, and finally the physical performance data of the underwear, such as tensile strength, tear strength, and thickness uniformity, are tested using professional equipment and technology.

[0114] Data Collection and Analysis:

[0115] The comfort rating method is: the rating range is set to 1-10 points, with 10 points being the highest comfort level. The data analysis method for the comfort rating is: comparing the average ratings of the two groups of underwear.

[0116] Durability was scored by setting the score range from 1 to 10, with 10 being the highest durability. Durability was analyzed by comparing the average scores of the two groups of underwear.

[0117] The testing methods for physical performance data are as follows: Testing tensile strength (unit: N): Comparing the maximum tensile force of the two groups of underwear measured on a tensile testing machine. Testing tear strength (unit: N): Comparing the maximum tear force of the two groups of underwear measured on a tear testing machine. Testing thickness uniformity (unit: mm): Comparing the thickness distribution of the two groups of underwear measured under a microscope.

[0118] Experimental results and analysis:

[0119] Experimental results data table 1

[0120]

[0121] Through the experimental data and comparative analysis of the above experimental result data table 1, the following conclusions can be drawn: the disposable underwear made in Example 1 is more comfortable than the disposable underwear made in the comparative example and the disposable underwear made in Example 2, and in terms of durability, the disposable underwear made in Example 2 is significantly better than ordinary disposable underwear and slightly better than the disposable underwear made in Example 1. The disposable underwear made in Example 2 and Example 1 performs better in tensile strength and tear strength, which meets the expected design goals.

[0122] Although the embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations of the present invention. A person skilled in the art may change, modify, replace and vary the above embodiments within the scope of the present invention.

Claims

1. A method for producing a breathable fabric for underwear, characterized in that: The method comprises the following steps: S100, stretching the elastic surface to a preset length, obtaining the stress of the elastic surface when the elastic surface is stretched to the preset length, and calculating the average load stress of the elastic surface according to the stress of the elastic surface; wherein, S100 includes the following steps: S101, dividing the three-dimensional model of the elastic surface into regions by a loop subdivision algorithm; wherein, S101 includes subdividing the three-dimensional model of the elastic surface [3, 9] times by a loop subdivision algorithm, subdividing the three-dimensional model of the elastic surface into K sub-regions, and using S1={s1(i)} to represent the set of sub-regions of the three-dimensional model of the elastic surface, s1(i) represents the i-th sub-region, i∈[1,K], and further using a free meshing algorithm to complete meshing of the three-dimensional model of the elastic surface to obtain the meshed The three-dimensional model of the divided elastic surface; S102, calculating the average load stress of the elastic surface; wherein the method of S102 is to obtain the stress value of each grid in the three-dimensional model of the divided elastic surface; wherein the stress value of the grid is the average stress value of all pixel points in the grid; obtain the number of grids in s1(i) as G, and use a(i, j) to represent the stress value in the grid with sequence number j in s1(i), j∈[1,G], calculate the maximum stress value in each grid in s1(i) as the easy-to-fall stress value am(i), and obtain the median ag(i) of the stress value in each grid in s1(i); calculate the average load stress UIS(i) of s1(i) by the first equation; wherein the first equation is: ； S103, traversing the sub-regions of the three-dimensional model of each elastic surface in turn, and obtaining the maximum average load stress of the three-dimensional model of the divided elastic surface; wherein the method of S103 is to obtain the average load stress of each sub-region through the first equation, compare the average load stress of each sub-region, and record the maximum average load stress among the average load stresses of each sub-region as UISM; S200, shearing the elastic surface and obtaining the stress distribution of the elastic surface after shearing; obtaining the force-trapped vulnerable area of ​​the elastic surface after shearing through the average load stress of the elastic surface, and calculating the thickness difference that needs to be adjusted in the force-trapped vulnerable area; wherein S200 includes: S201, recording the sub-area in the three-dimensional model of the elastic surface after shearing where each stress is greater than the maximum average load stress as the force-trapped vulnerable area, and extracting the sequence number of the force-trapped vulnerable area as z, where z is the sequence number of the force-trapped vulnerable area; S202, taking the average thickness value of all grids in the force-trapped vulnerable area as the original average thickness value UC(z); S203, calculating the thickness difference UX(z) that needs to be adjusted in the force-trapped vulnerable area; wherein the method of S203 is to form a sequence of the average load stresses of each sub-area of ​​the three-dimensional model of the elastic surface as a write sequence Ust; calculating the average value RK of the ratios between all average load stresses and UISM in Ust, that is: ； The thickness difference UX(z) that needs to be adjusted is the original average thickness value UC(z) multiplied by F, where F is the absolute value of 1 minus RK divided by e; where e is the base of the natural constant; S300, hot-pressing and bonding the elastic supplementary surface having a thickness equal to the thickness difference to the force-trapped vulnerable region of the sheared elastic surface to obtain a hot-pressed elastic surface; S400, heat-pressing and bonding the first outer layer sheet, the heat-pressed elastic surface and the second outer layer sheet to obtain a fabric of disposable underwear.

2. The method for producing a breathable fabric for underwear according to claim 1, characterized in that: The breathable fabric for underwear includes: a first outer layer, an elastic surface and a second outer layer, wherein the first outer layer is a waterproof breathable non-woven fabric and an antibacterial shielding non-woven fabric, and the second outer layer is a hygroscopic non-woven fabric and a soft non-woven fabric; wherein the waterproof breathable non-woven fabric is manufactured by: using melt-extruded polymer particles, expanding them into fibers through high-speed airflow, and then solidifying them through hot rollers or chemical treatment to form non-woven fabrics, and then adding additives; the antibacterial shielding non-woven fabric is manufactured by: fixing the fibers together through chemical adhesives to form fabrics, and adding antibacterial agents or shielding agents during the manufacturing process; the hygroscopic non-woven fabric is manufactured by: using water as a medium, suspending the fibers in water, collecting them through a mesh belt or a roller to form fabrics; the soft non-woven fabric is manufactured by: mechanically winding and interweaving the fiber layers through a needle punching machine to form a tightly structured but soft fabric.

3. The method for producing a breathable fabric for underwear according to claim 1, characterized in that: In step S100, the device for stretching the elastic surface to a preset length is a tensile testing machine, which is provided with a three-dimensional scanner and a stress detector; wherein the elastic surface is a combination of one or more elastic fibers, elastic fabrics or elastic foams.

4. The method for producing a breathable fabric for underwear according to claim 3, characterized in that: The method for obtaining the stress of an elastic surface when it is stretched to a preset length includes: obtaining a three-dimensional model of the elastic surface by scanning with a three-dimensional scanner, obtaining the stress of the elastic surface with a stress detector, adding the distribution and data of the stress of the elastic surface to the three-dimensional model of the elastic surface, and adding the thickness data of the elastic surface to the three-dimensional model of the elastic surface.

5. The method for producing a breathable fabric for underwear according to claim 1, characterized in that: In step S200, shearing the elastic surface and obtaining the stress distribution of the sheared elastic surface includes: According to the design requirements and the characteristics of the fabric, determine the appropriate shearing mode and size; wherein the shearing mode includes: a combination of one or more of straight line cutting, curve cutting or cutting of a specific shape; then the elastic fabric is sheared according to the design requirements and mode, ensuring that the elastic fabric is not damaged or twisted during the cutting process to maintain its structural integrity, and finally a stress detector is used to obtain the stress of the elastic surface after shearing, and the distribution and data of the stress of the elastic surface are added to the three-dimensional model of the divided elastic surface, and recorded as the three-dimensional model of the elastic surface after shearing.

6. A disposable underwear, characterized in that: The production process of the disposable underwear comprises: First, evenly lay the first elastic band, the second elastic band or the shrink film on the flat breathable fabric; on the breathable fabric with the elastic band or the shrink film laid, cover a layer of breathable fabric with the same size as the lower layer in an aligned manner; then use high-frequency welding to firmly bond the upper and lower layers of fabric together, so that the elastic band or the shrink film is fixed between the two layers of breathable fabric, fold the bonded breathable fabric in half along the center line in the length direction, and after folding, lay the fabric flat to form a double-layer structure; use heat sealing or ultrasonic compounding technology to connect the two ends of the breathable fabric together to form a ring body, which constitutes the basic shape of the underwear; Wherein, the breathable fabric is made by the production method of breathable fabric for underwear according to claim 1.

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