Air-permeable nonwoven fabric

Abstract

The utility model discloses a kind of breathable nonwoven fabrics, it is related to cloth technical field.It is formed by at least two layers of superposed weaving, forming breathable nonwoven fabric, including cloth layer structure;Several breathable laminates are distributed between two cloth layer structures, and each cloth layer structure is according to the position distribution of internal weaving filler, complete moisture gas from nonwoven fabric surface layer infiltration, and complete moisture absorption, so that dry gas is discharged from nonwoven fabric bottom layer.The utility model realizes the efficient treatment of moisture gas and the smooth discharge of dry gas by the composite design of cloth layer structure and the gradient setting of breathable laminate, wherein the adsorption textile layer of first cloth layer structure and hollow spinning layer cooperatively constitute breathable unit layer, which can accurately capture moisture and impurities, and also can ensure gas circulation, the residence spinning layer of second cloth layer structure prolongs the contact time of moisture gas, and the adsorption filler layer regulates the dry gas flow path, and the two cooperate to further improve the moisture capture efficiency.

Description

Technical Field

[0001] This utility model relates to the field of fabric technology, specifically to a breathable nonwoven fabric. Background Technology

[0002] Traditional nonwoven fabrics often suffer from the problem of not being able to balance breathability and moisture absorption. Some products sacrifice moisture trapping ability to improve breathability, which can easily lead to damp and stuffy conditions during use. Therefore, it is necessary to design a breathable nonwoven fabric.

[0003] A search revealed that Chinese utility model patent application with publication number "CN223030542U" proposes "a breathable nonwoven fabric". The breathable cavity formed between the breathable layer and the base layer allows water vapor to evaporate through air circulation, and the moisture-wicking cavity absorbs excess water vapor. The coarse yarn count forms a denser moisture-wicking layer, which, combined with the fiber characteristics, allows water vapor to escape. At the same time, the dense structure can prevent the intrusion of external water vapor, thus forming a breathable, moisture-wicking and waterproof nonwoven fabric.

[0004] However, in actual use, the above-disclosed device structures and similar existing technologies often suffer from several drawbacks. Firstly, the air vents in these existing technologies are mostly rigid or semi-rigid fixed cavity structures. When the nonwoven fabric is subjected to stretching, compression, or other external forces during daily use, the air vents are prone to deformation or even collapse, leading to blockage of the permeable channels. This results in a significant decrease in breathability after prolonged use. Secondly, the flow path design of humid gas in the air vents and moisture-wicking chambers is relatively simple, mostly involving short, straight-line diffusion. This results in insufficient contact time with the moisture-absorbing layer, preventing the moisture in the air from being fully captured. Some unabsorbed moisture flows back to the surface with the gas, causing localized dampness and stuffiness during use. Utility Model Content

[0005] The purpose of this invention is to provide a breathable nonwoven fabric to solve the problems mentioned in the background art.

[0006] To achieve the above objectives, this utility model provides the following technical solution:

[0007] A breathable nonwoven fabric includes: a fabric layer structure, which is formed by at least two layers stacked and woven together to form a breathable nonwoven fabric;

[0008] Several breathable layers are distributed between the two fabric layers. Each fabric layer is distributed according to the position of the internal woven filling material, so that the humid gas can penetrate from the non-woven fabric surface layer and complete the absorption of moisture, and the dry gas can be discharged from the non-woven fabric bottom layer.

[0009] The fabric layer structure is divided into a first fabric layer structure and a second fabric layer structure. The breathable non-woven fabric is composed of the first fabric layer structure combined with itself or the second fabric layer structure layered and woven.

[0010] The first layer structure includes:

[0011] The absorbent textile layer is used to capture dust, impurities, and moisture from the air.

[0012] Hollow spun layers are woven into both ends of the absorbent spun layer for breathability. The absorbent spun layer and the hollow spun layers at both ends together form a breathable unit layer.

[0013] Linked textile knots are used to connect two breathable unit layers and form any single-layer structure in the top or bottom layer of a breathable nonwoven fabric.

[0014] Furthermore, the second layered structure includes:

[0015] The retention layer is used to retain humid gas, prolong its contact time with the adsorbed textile layer in the first fabric layer structure, improve the moisture capture efficiency, and at the same time keep the gas channel open, so that dry gas can diffuse smoothly through the breathable stack to the bottom layer.

[0016] An adsorption filling layer, woven into the two sides of the retention layer, is used to guide the dry gas to flow along a preset path and prevent the gas from accumulating disorderly in the fabric layer.

[0017] Adsorption textile knots are set at the edges of the second fabric layer structure to fix the multiple retention textile layers and adsorption filling layers in the second fabric layer structure and prevent interlayer separation.

[0018] Furthermore, the breathable layer is made of interwoven elastic breathable fibers, and its layer diameter gradually increases from the first fabric layer structure to the second fabric layer structure, which is used to guide the humid gas to accumulate in the adsorption textile layer and reduce the resistance when dry gas is discharged.

[0019] Furthermore, adjacent breathable layers are connected by the surface of either the first or the second fabric structure to maintain breathability when the layered structure is subjected to external tension.

[0020] Furthermore, when the breathable nonwoven fabric is woven from the same first layer structure, the hollow woven layers at corresponding positions in the upper and lower layers are aligned vertically to form a through breathable channel. Moist gas passes through each hollow woven layer in sequence along this channel and enters the corresponding absorbent woven layer. Each absorbent woven layer corresponds one-to-one with the corresponding breathable layer above and below. The axial direction of the breathable layer is consistent with the extension direction of the absorbent woven layer, guiding the moist gas to diffuse evenly between the layers. The dry gas is collected by each hollow woven layer and discharged uniformly from the bottom layer.

[0021] Furthermore, when the breathable nonwoven fabric is woven from the same second fabric layer structure, the retention layers at corresponding positions in the upper and lower layers are aligned vertically to form a continuous space for moisture retention. After entering the surface retention layer, the moisture diffuses in a serpentine manner within the retention space, extending the contact time with each layer of adsorption filling. Each layer of adsorption filling extends along both sides of the retention layer and connects with the corresponding breathable layers above and below, forming a continuous path for guiding dry gas. The stack diameter of the breathable layers gradually increases from the upper second fabric layer structure to the lower second fabric layer structure, guiding the dry gas to converge towards the bottom layer along this path and reducing the channel resistance during discharge. After the moisture is retained multiple times by each layer of retention layer, the moisture is gradually adsorbed and locked by the adsorption filling layer. The dry gas is then collected and discharged evenly through the gap between the bottom retention layer and the breathable layers.

[0022] Furthermore, when the breathable nonwoven fabric is woven from a first layer structure and a second layer structure, the hollow spun layer of the first layer structure and the retention spun layer of the second layer structure are aligned vertically to form an "intake and retention" through channel. Moist gas enters from the hollow spun layer of the first layer structure and is guided into the retention spun layer of the second layer structure through the corresponding breathable layer. It diffuses in a serpentine manner within the continuous space of the retention spun layer, prolonging the contact time with the adsorption spun layer of the first layer structure and the adsorption filling layer of the second layer structure, thus completing the dual capture of moisture. The stack diameter of the breathable layer gradually increases from the first layer structure to the second layer structure, which guides the moisture to gather in the retention spun layer while reducing the channel resistance when the dry gas is discharged. The adsorption spun layer and the breathable layer are axially aligned, guiding the moisture to diffuse evenly. The adsorption filling layer and the breathable layer are connected to form a dry gas guide path. The dry gas is discharged from the bottom layer after being collected by the retention spun layer and the breathable layer of the second layer structure.

[0023] Compared with the prior art, the beneficial effects of this utility model are:

[0024] This breathable nonwoven fabric achieves efficient handling of humid gas and smooth discharge of dry gas through the composite design of the fabric layer structure and the gradient setting of the breathable layers. The first fabric layer structure, with its adsorption textile layer and hollow textile layer working together, forms a breathable unit layer that can accurately capture moisture and impurities while ensuring gas flow. The second fabric layer structure, with its retention textile layer, extends the contact time of humid gas, while the adsorption filling layer regulates the flow path of dry gas. The two work together to further improve the moisture capture efficiency.

[0025] The interlacing characteristics of the elastic fibers in the breathable layer and the gradually increasing layer diameter from top to bottom not only guide the humid gas to gather in the adsorption area, but also ensure the resistance to the discharge of dry gas. Combined with the fixing effect of the associated textile knots and the adsorption textile knots, it ensures that the layered structure can maintain stable breathability under tension. Attached Figure Description

[0026] Figure 1 This is a planar cross-sectional view of the first fabric layer structure of this utility model;

[0027] Figure 2 This is a diagram showing the composition of the first layered structure of this utility model;

[0028] Figure 3 This is a planar cross-sectional view of the second fabric layer structure of this utility model;

[0029] Figure 4 This is a diagram showing the composition of the second layer structure of this utility model.

[0030] In the diagram: 1. First fabric layer structure; 101. Hollow spinning layer; 102. Adsorption spinning layer; 103. Linked spinning joint; 2. Breathable layer; 3. Second fabric layer structure; 301. Retention spinning layer; 302. Adsorption filling layer; 303. Adsorption spinning joint. Detailed Implementation

[0031] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0032] Before understanding the technical solution proposed in this application, it is important to understand that in the actual preparation of the breathable nonwoven fabric proposed in this application, the first step is to select a fiber material with high moisture absorption performance (such as a blend of bamboo fiber and polyester fiber in a 3:7 mass ratio) to prepare an absorbent textile layer 102. A base layer with a thickness of 0.2-0.3 mm is formed through plain weave. Then, hollow textile layers 101 are woven along the length of both ends of the absorbent textile layer 102—using hollow polypropylene fibers, fixed with a twill weave. The width of the hollow textile layer 101 is 1 / 4-1 / 3 of the absorbent textile layer 102, and the spacing between the hollow textile layers 101 at both ends is consistent with the designed length of the breathable unit layer. Two adjacent breathable unit layers are connected along the width direction using associated textile knots 103 (woven from nylon filaments) to form a single-layer structure of the first fabric layer structure 1. The spacing of the associated textile knots 103 is 5-8cm to ensure the stability of the breathable unit layer. Then, breathable layers 2 are formed by weaving elastic breathable fibers (such as polyurethane elastic fibers and cotton fibers blended in a 1:1 ratio) and the layer diameter gradually increases from 0.5mm to 1.2mm from the first fabric layer structure 1 to the second fabric layer structure 3. The layers are fixed to the surface of the first fabric layer structure 1 by knitting. The spacing between adjacent breathable layers 2 is 3-5cm and corresponds one-to-one with the position of the absorbent textile layer 102.

[0033] It is worth noting that if a breathable nonwoven fabric composed of a first fabric layer structure 1 and a second fabric layer structure 3 is to be prepared, the hollow spun layer 101 of the first fabric layer structure 1 and the retention spun layer 301 of the second fabric layer structure 3 should be aligned vertically and fixed by hot pressing (temperature 120-140℃, pressure 0.3-0.5MPa) to ensure the unobstructed passage of the "air intake and retention" channel. The retention spun layer 301 of the second fabric layer structure 3 is formed by satin weaving of polyester short fibers with a thickness of 0.15-0.25mm. Adsorption filling layers 302 (made of viscose fiber and flax fiber blend) are woven on both sides. The adsorption filling layers 302 extend along the length of the retention spun layer 301 and are fixed with a locking edge process at the junction with the breathable overlay 2 to prevent interlayer separation. Finally, the overall structure is cold-pressed and shaped (temperature 25-30℃, pressure 0.2MPa, time 10-15min) to ensure the elastic recovery performance of the breathable laminate 2 and the stability of each fabric layer structure, thus completing the preparation of the breathable nonwoven fabric.

[0034] It should be added that during the preparation process, the weaving density of each layer (the weaving density of the first fabric layer structure 1 is 200-250 threads / 10cm, and the weaving density of the second fabric layer structure 3 is 180-220 threads / 10cm) and the elastic recovery rate of the breathable layer 2 (≥85%) must be strictly controlled to ensure that the air vent does not deform or collapse under the action of external forces such as stretching and compression, and to maintain long-term stable air permeability.

[0035] like Figures 1-4 As shown, this utility model proposes a breathable nonwoven fabric, including: a fabric layer structure, which is composed of at least two layers precisely stacked and woven together to form a nonwoven fabric body with excellent breathability.

[0036] It is worth noting that in this technical solution, several breathable layers 2 are evenly distributed between the two fabric layers. Each fabric layer is laid out and distributed according to the position of its internal woven filling material, so as to complete the process of efficient penetration of humid gas from the non-woven fabric surface layer and achieve sufficient moisture absorption function inside, so as to ensure that dry gas can be smoothly discharged from the bottom layer of the non-woven fabric.

[0037] Specifically, the fabric layer structure is mainly divided into a first fabric layer structure 1 and a second fabric layer structure 3. The overall structure of the breathable nonwoven fabric is achieved by combining the first fabric layer structure 1 with itself, or by layering and weaving it with the second fabric layer structure 3.

[0038] refer to Figure 1 and Figure 2As can be seen, in this technical solution, the first fabric layer structure 1 is specifically composed as follows: an adsorption textile layer 102, used to effectively capture moisture contained in the air and dust impurities carried in the airflow; a hollow textile layer 101, woven at both ends of the adsorption textile layer 102, mainly undertaking the function of breathability; the adsorption textile layer 102 and the hollow textile layer 101 connected at both ends together constitute a complete and functionally independent breathable unit layer; and a connecting textile joint 103, used to reliably connect two adjacent breathable unit layers, and thereby jointly constitute any single layer structure in the surface or bottom layer of the overall structure of the breathable nonwoven fabric.

[0039] In addition, refer to Figure 3 and Figure 4 As can be seen, in this technical solution, the second fabric layer structure 3 includes: a retention layer 301, which is used to actively retain the passing humid gas, prolonging its residence time inside the structure, thereby increasing the contact time between the humid gas and the adsorption textile layer 102 in the first fabric layer structure 1, effectively improving the moisture capture efficiency; an adsorption filling layer 302, woven on the inner and outer sides (or upper and lower sides) of the retention layer 301, which is used to guide the dry gas to flow in a directional manner along a preset optimized path, effectively avoiding disordered accumulation or eddy formation of gas inside the fabric layer; and an adsorption textile knot 303 set at the key edge position of the second fabric layer structure 3, the function of which is to firmly fix the core components inside the multiple second fabric layer structures 3—the retention layer 301 and the adsorption filling layer 302—preventing separation between the layers during use and ensuring long-term structural stability.

[0040] It is worth noting that in this technical solution, the characteristics and functions of the breathable layer 2 include: the breathable layer 2 is precisely interwoven with breathable fibers of good elasticity; the layer diameter (cross-section / guide path of the interlayer channel) of the breathable layer 2 gradually increases from the first fabric structure 1 to the second fabric structure 3. This gradually increasing design mainly serves two functions: first, to guide humid gas to accumulate more efficiently in the adsorption textile layer 102 area, increasing contact opportunities; and second, to significantly reduce the channel resistance faced by dry gas when it is finally discharged. Adjacent breathable layers 2 are reliably connected through the surface structure of either the first fabric structure 1 or the second fabric structure 3. It should be noted that the core purpose of this connection method is to ensure that the overall breathability of the entire layer structure can be effectively maintained even when subjected to external tensile deformation, and that it will not be blocked due to deformation.

[0041] It should also be noted that, in this technical solution, the gas flow mechanism varies under different weaving combinations:

[0042] 1. When the breathable nonwoven fabric is woven from the same first fabric layer structure 1: the hollow spun layers 101 at corresponding positions in the upper and lower layers will be precisely aligned in the vertical direction, thereby forming a series of through vertical breathable channels. Moist gas first passes through the hollow spun layers 101 of each layer in sequence along these preset channels, and then enters the corresponding absorbent spun layers 102. The absorbent spun layers 102 in each independent layer form a one-to-one correspondence with the breathable stacked layers 2 above and below them. The axial direction (i.e. the main guiding direction) of the breathable stacked layers 2 is consistent with the extension direction of the absorbent spun layers 102. This design guides the moist gas to achieve uniform diffusion between adjacent fabric layers. The dry gas generated after the moisture adsorption is completed is collected by the hollow spun layers 101 of each layer and finally discharged uniformly from the bottom layer of the nonwoven fabric.

[0043] 2. When the breathable nonwoven fabric is woven from the same second fabric layer structure 3: the retention layers 301 of the upper and lower layers at corresponding positions are also strictly and precisely aligned in the vertical direction, together forming a continuous three-dimensional space dedicated to the retention of moisture. Moisture first enters the surface retention layer 301, and then diffuses in a serpentine (or meandering) manner within this continuous retention space. This arrangement prolongs the contact time between the moisture and the adsorption filling layers 302 of each layer. The adsorption filling layers 302 in each layer extend along both sides (or vertically) of the retention layer 301. The fabric is woven together and seamlessly connected with the adjacent breathable layers 2, forming a continuous and efficient dry gas flow path. The layer diameter of the breathable layer 2 gradually increases from the upper second fabric layer 3 to the lower second fabric layer 3. This gradually expanding structure effectively guides the dry gas to smoothly converge towards the bottom layer along the preset flow path, reducing the channel resistance when the gas is finally discharged. After the humid gas passes through each layer of retention fabric layer 301 for multiple retention processes, the moisture contained in the gas is gradually adsorbed and firmly locked by the adsorption filling layer 302. Finally, the gas that has completed the drying process is collected and evenly discharged through the carefully designed gap between the bottom retention fabric layer 301 and the breathable layer 2.

[0044] 3. When the breathable nonwoven fabric is woven from the first layer structure 1 and the second layer structure 3 (hybrid structure): the hollow spun layer 101 in the first layer structure 1 on the surface is precisely aligned vertically with the retention spun layer 301 in the second layer structure 3 below it, forming a "breathing and retaining" through composite channel. Moist gas first enters from the hollow spun layer 101 of the first layer structure 1 on the surface, and then, guided by the breathable layer 2 at the corresponding position, is efficiently introduced into the retention spun layer 301 of the second layer structure 3 below. Moist gas diffuses in a serpentine (winding) manner within the continuous space provided by the retention layer 301. This design significantly prolongs the sufficient contact time between the gas and the adsorption textile layer 102 of the first fabric structure 1 and the adsorption filling layer 302 of the second fabric structure 3, achieving dual protection of moisture capture (initial capture and secondary locking). The stacking diameter of the breathable stack 2 is also designed to gradually increase from the first fabric structure 1 to the second fabric structure 3. This design guides the moist gas to gather more efficiently in the retention layer 301 area and continuously reduces the channel resistance faced by the dry gas during the discharge process. In addition, it should be noted that the arrangement direction of the adsorption textile layer 102 is consistent with the axis of the breathable stack 2, ensuring that the moist gas is uniformly diffused between the layers. At the same time, the adsorption filling layer 302 and the breathable stack 2 are closely connected, forming an efficient flow path for the dry gas. Finally, the gas that has completed the drying process is collected by the retention layer 301 of the second fabric structure 3 and the breathable stack 2, and then uniformly discharged from the bottom layer of the nonwoven fabric.

[0045] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the appended embodiments and their equivalents.

Claims

1. A breathable nonwoven fabric, characterized in that, include: The fabric structure consists of at least two layers woven together to form a breathable nonwoven fabric. Several breathable layers (2) are distributed between the two fabric layers. Each fabric layer is distributed according to the position of the internal woven filling material, so that the humid gas can penetrate from the non-woven fabric surface layer and absorb the moisture, and the dry gas can be discharged from the bottom layer of the non-woven fabric. The fabric layer structure is divided into a first fabric layer structure (1) and a second fabric layer structure (3). The breathable nonwoven fabric is composed of the first fabric layer structure (1) combined with itself or the second fabric layer structure (3) layered and woven. The first layered structure (1) includes: The absorbent textile layer (102) is used to capture dust, impurities, and moisture in the air. Hollow spun layers (101) are woven at both ends of the absorbent spun layers (102) for breathability. The absorbent spun layers (102) and the hollow spun layers (101) at both ends together constitute a breathable unit layer. Linked textile joints (103) are used to connect two breathable unit layers and form any single-layer structure in the top or bottom layer of the breathable nonwoven fabric.

2. The breathable nonwoven fabric according to claim 1, characterized in that: The second layered structure (3) includes: The retention layer (301) is used to retain humid gas, prolong its contact time with the adsorbed textile layer (102) in the first fabric structure (1), improve the moisture capture efficiency, and at the same time keep the gas channel open so that the dry gas can diffuse smoothly through the breathable stack (2) to the bottom layer. The adsorption filling layer (302) is woven into both sides of the retention spinning layer (301) to guide the dry gas to flow along a preset path and prevent the gas from accumulating disorderly in the fabric layer; Adsorption textile joints (303) are set at the edge of the second fabric layer structure (3) to fix the multiple retention textile layers (301) and adsorption filling layers (302) in the second fabric layer structure (3) to prevent interlayer separation.

3. The breathable nonwoven fabric according to claim 1, characterized in that: The breathable layer (2) is made of interwoven elastic breathable fibers, and its layer diameter gradually increases from the first fabric layer structure (1) to the second fabric layer structure (3), which is used to guide the humid gas to gather in the adsorption textile layer (102) and reduce the resistance when the dry gas is discharged.

4. The breathable nonwoven fabric according to claim 3, characterized in that: Adjacent breathable layers (2) are connected by the surface of either the first fabric structure (1) or the second fabric structure (3) to maintain breathability when the layered structure is subjected to external force stretching.

5. The breathable nonwoven fabric according to claim 1, characterized in that: When the breathable nonwoven fabric is woven from the same first layer structure (1), the hollow spun layers (101) at corresponding positions of the upper and lower layers are aligned in the vertical direction to form a through breathable channel. Moist gas passes through each hollow spun layer (101) in sequence along the channel and enters the corresponding absorbent spun layer (102). Each absorbent spun layer (102) corresponds one-to-one with the corresponding breathable stack (2) above and below. The axial direction of the breathable stack (2) is consistent with the extension direction of the absorbent spun layer (102), which guides the moist gas to diffuse evenly between the layers. The dry gas is collected by each hollow spun layer (101) and discharged uniformly from the bottom layer.

6. The breathable nonwoven fabric according to claim 1, characterized in that: When the breathable nonwoven fabric is woven from the same second fabric layer structure (3), the retention layers (301) at corresponding positions of the upper and lower layers are aligned in the vertical direction to form a continuous space for the retention of humid gas. After the humid gas enters the surface retention layer (301), it diffuses in a serpentine manner in the retention space, prolonging the contact time with each layer of adsorption filling layer (302). The adsorption filling layer (302) of each layer extends along both sides of the retention layer (301) and connects with the corresponding breathable stack (2) above and below, forming a continuous dry gas guiding path. The stack diameter of the breathable stack (2) gradually increases from the upper second fabric layer structure (3) to the lower second fabric layer structure (3), guiding the dry gas to converge to the bottom layer along this path and reducing the channel resistance when it is discharged. After the humid gas is retained multiple times by each layer of retention layer (301), the moisture is gradually adsorbed and locked by the adsorption filling layer (302). After the dry gas is collected, it is evenly discharged from the gap between the bottom retention layer (301) and the breathable stack (2).

7. The breathable nonwoven fabric according to claim 1, characterized in that: When the breathable nonwoven fabric is woven from a first layer structure (1) and a second layer structure (3), the hollow spun layer (101) of the first layer structure (1) and the retention spun layer (301) of the second layer structure (3) are aligned vertically to form an "air intake and retention" through channel. Moist gas enters from the hollow spun layer (101) of the first layer structure (1) and is then introduced into the retention spun layer (301) of the second layer structure (3) through the corresponding breathable layer (2). It diffuses in a serpentine manner in the continuous space of the retention spun layer (301), extending its extension to the adsorption spun layer (102) of the first layer structure (1) and the second layer structure. The contact time of the adsorption filling layer (302) of the structure (3) completes the dual capture of moisture. The stacking diameter of the breathable stack (2) gradually increases from the first fabric structure (1) to the second fabric structure (3). It is used to guide the humid gas to gather in the retention spinning layer (301) while reducing the channel resistance when the dry gas is discharged. The adsorption spinning layer (102) and the breathable stack (2) are aligned axially to guide the humid gas to diffuse evenly. The adsorption filling layer (302) and the breathable stack (2) are connected to form a dry gas guide path. The dry gas is discharged from the bottom layer after being collected by the retention spinning layer (301) and the breathable stack (2) of the second fabric structure (3).

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