Composite material and absorption article

Abstract

The utility model relates to the technical field of special performance products and composite materials, in particular to a composite material and an absorption article, and the composite material comprises an EPTFE (Expanded Polytetrafluoroethylene) film and a moisture-proof and gas-proof film which are laminated; a through hole is formed in the moisture-proof and gas-proof film; the EPTFE film and the moisture-proof and gas-proof film are bonded and fixed in partial areas; the moisture and gas insulation film is in direct contact with the EPTFE film, or a barrier layer is arranged between the moisture and gas insulation film and the EPTFE film. The composite material provided by the utility model has the advantages of high air permeability and low moisture permeability, so that part of moisture can be discharged from the core body, and the external environment cannot be influenced. In addition, residual liquid in the interlayer space can be sucked back into the absorption layer through the through holes, so that the air permeability of the composite material is kept, and the composite material has good comfort and leakage resistance.

Description

Technical Field

[0001] This utility model relates to the field of special performance products and composite materials, specifically to a composite material and absorbent material. Background Technology

[0002] During the use of disposable absorbent products (especially when used for a long time or when it is inconvenient to replace them), a large amount of hot and humid vapor will accumulate inside the product. If this moisture is not removed in time, it will cause the body to feel stuffy and hot, and in severe cases, even redness and inflammation. Therefore, the bottom layer (away from the user's skin) of disposable absorbent products is often designed to be made of breathable but liquid-proof material to expel moisture while keeping the liquid from leaking, that is, the liquid is retained by the absorbent core.

[0003] The breathable but liquid-impermeable base material of conventional disposable absorbent products is a PE membrane. PE membranes are often produced using a casting process: a certain proportion (e.g., 30-50%) of calcium carbonate particles are added to a PE resin carrier for blending. Because PE resin is a thermoplastic material, it can be stretched and crystallized under certain conditions. During stretching, interfacial delamination occurs between the polymer and the calcium carbonate particles, forming interconnected, meandering pores or channels around the calcium carbonate particles. These small number of pores and channels give the PE membrane its low moisture permeability (approximately 2300 g / m³). 2 The data above shows that PE film has poor breathability (approximately 0.2 mm / s) and micro-breathability (approximately 0.2 mm / s), which can easily cause a stuffy feeling. This is because disposable absorbent products form a closed microclimate on the user's skin surface during use, which is different from the external environment. The temperature and humidity in this microclimate will fluctuate to a certain extent with the body temperature, the outdoor environment, or the production of excrement. Due to the micro-breathability of PE film, gas and temperature and humidity cannot be exchanged with the external environment. Therefore, even if there is no excrement, the stuffy feeling will continue.

[0004] In existing technologies, a breathable bottom layer material has been developed. For example, the breathable bottom layer shown in CN220826379U mainly refers to EPTFE composite material, which is often produced using a biaxial stretching process. The EPTFE membrane is composed of countless micro / nanofibers, which overlap to form numerous micropores. This high porosity gives the EPTFE composite material high moisture permeability (approximately 3500 g / m³). 2 This material boasts a high permeability (approximately 60 mm / s) and a 24-hour airflow rate. It solves the problem of stuffiness and lack of breathability in the bottom layer of disposable absorbent materials, allowing free airflow between the inside and outside of the finished product. This facilitates moisture wicking and heat reduction, improving comfort. However, some issues have been observed during actual use:

[0005] (1) Due to the specific nature of the users and scenarios for disposable absorbent products, such as when infants wear diapers close to their skin while out and about, and when sleeping at night, when there are bedding underneath the diapers, and when adults wear diapers while driving, performing, or in bed, the products are used for extended periods. In actual use, it was found that although EPTFE composite material has high breathability, it also results in high moisture permeability of the finished product, leading to dampness on the outer clothing or bedding, which raises negative associations among consumers regarding the possibility of leakage.

[0006] Due to the high porosity and porous nature of EPEFE membranes, humid and hot gases exhaled by the human body can penetrate the surface layer and absorbent core to reach the bottom layer of the EPEFE composite material. These gases then diffuse into the external environment along the numerous micropores of the EPEFE membrane, resulting in excessively high moisture permeability in the finished product for a short period. Moisture permeability tests show that, compared to PE membranes, the moisture permeability of products using EPE membranes is approximately twice that of PE membranes (from approximately 0.8 g / 10 min to 2.4 g / 10 min).

[0007] However, the expulsion of moisture is beneficial to the human body. If moisture is blocked from being expelled from the core, the temperature and humidity between the absorbent and the human skin will be too high, resulting in a stuffy feeling similar to that of a PE film. Therefore, the best solution is to allow moisture to be expelled from the core without affecting the external environment.

[0008] Due to factors such as production process, cost, and performance, the basis weight of EPTFE membrane in EPTFE composite materials is low (approximately 2.0 gsm). The low basis weight and thinness result in shorter channel lengths for the micropores within the EPTFE membrane. In addition to the easy diffusion of moisture, the cold ambient temperature can also be easily conducted to the inner side of the EPTFE membrane (because the core has a high basis weight and is fluffy, it is difficult for low temperatures to continue to conduct upwards to human skin). This causes some moisture to condense into liquid, adhering to the EPTFE membrane surface (near the core side) or being absorbed by the core. The residual liquid not only covers the moisture-permeable and breathable micropores of the EPTFE membrane, affecting moisture and air permeability, but also has a certain wetting effect on the membrane due to prolonged contact with the liquid, which may increase the risk of leakage.

[0009] In order to maintain the air permeability and overall cost of EPTFE composite materials, it is not advisable to use membranes with high basis weight. Furthermore, since EPTFE membranes lose some air permeability (about 50%) during the lamination process, simply reducing the porosity of the EPTFE membrane to reduce the moisture permeability of the finished product is unlikely to meet the high air permeability requirements of the finished product (about 60 mm / s), and will also produce a stuffy feeling similar to that of PE membranes.

[0010] Therefore, the reason why finished products using EPTFE composite material as the bottom layer have a high moisture permeability is mainly because a large amount of moisture permeates through the EPTFE composite material and diffuses into the external environment in a short period of time, which may even cause the outer clothing to become damp.

[0011] (2) EPTFE composite material is made of EPTFE film and non-woven fabric. In its promotion as a leak-proof bottom film for diapers, it was found that although the hydrostatic pressure and leak-proof performance of EPTFE composite material meet practical usage requirements, some manufacturers still state that EPTFE composite material needs to meet enterprise standard leak-proof test standards similar to PE film: resistance to compression leakage and resistance to pressing leakage. However, current EPTFE composite materials do not fully meet these two test standards.

[0012] Specifically, EPTFE composites are often nonwoven fabric-EPTFE laminated composites, or nonwoven fabric-EPTFE-nonwoven fabric laminated composites. The EPTFE membrane has a low basis weight (approximately 2.0 gsm) and a porous structure, which makes it prone to deformation or tearing of the microporous structure under significant external forces, leading to leaks. Although the nonwoven fabric lamination increases the EPTFE membrane's resistance to deformation, leaks still easily occur under perpendicular external forces, such as compression or pressing. Research shows that the micropores of the EPTFE membrane are formed by countless interconnected micro- and nano-scale fibers within the membrane. When such perpendicular external forces act on the EPTFE membrane surface, the microfibers are easily deformed, displaced, or broken, resulting in changes in pore size or the appearance of leaks. Besides the magnitude of the external force, the degree of deformation is also related to factors such as the diameter of the microfibers (including diameter uniformity), density (including the number of layers), single fiber strength, and node spacing. Verification has shown that increasing the basis weight (or molecular weight of raw materials) of EPTFE membranes can improve the composite material's resistance to extrusion and pressure leakage. However, the basis weight (or molecular weight of raw materials) of EPTFE membranes is closely related to cost. Increasing the basis weight (or molecular weight of raw materials) of EPTFE membranes will double the cost. According to production experience, doubling the basis weight (or molecular weight of raw materials) of EPTFE membranes will double the cost. Excessive cost is not conducive to the market promotion and large-scale use of the product, nor can it reliably solve the problem.

[0013] In summary, in the existing technology, PE membranes are not suitable as breathable but liquid-impermeable bottom materials for absorbent products, while EPTFE membranes have their own defects. Utility Model Content

[0014] To address the aforementioned problems, the purpose of this utility model is to provide a composite material and an absorbent material.

[0015] The technical solution provided by this utility model is as follows:

[0016] In a first aspect, a composite material includes an EPTFE membrane and a moisture-proof and gas-proof membrane stacked together; the moisture-proof and gas-proof membrane has through holes; with the EPTFE membrane surface as the projection surface and a direction perpendicular to the EPTFE membrane surface as the projection direction, the projection of the through holes along the projection direction is located on the projection surface; the EPTFE membrane and the moisture-proof and gas-proof membrane are bonded and fixed in a certain area; the moisture-proof and gas-proof membrane is in direct contact with the EPTFE membrane, or a barrier layer is provided between the moisture-proof and gas-proof membrane and the EPTFE membrane.

[0017] As one possible technical solution in the first aspect, the diameters at both ends of all through holes are approximately equal; or the diameters at both ends of some through holes are approximately equal, while the diameter at one end of the remaining through holes is larger than the diameter at the other end; or the diameter at one end of all through holes is larger than the diameter at the other end.

[0018] Optionally, the larger diameter end of each through-hole faces the EPTFE membrane; or the smaller diameter end of each through-hole faces the EPTFE membrane; or some through-holes have the larger diameter end facing the EPTFE membrane, while the smaller diameter ends of the remaining through-holes face the EPTFE membrane.

[0019] Optionally, the inner diameter of the larger end of the through hole is denoted as Demax, and the inner diameter of the smaller end of the through hole is denoted as Demin, where 1 / 10 ≤ Demin / Demax < 1 / 1, and the value of Demin ranges from 0.05mm to 1.0mm.

[0020] Optionally, the moisture-proof and air-proof membrane has an opening ratio of 5% to 40% and an opening density of (1-1000)*10. 4 pcs / m 2 The value of Demin ranges from 0.05 mm to 0.5 mm.

[0021] As an optional technical solution in the first aspect, the air permeability of the moisture-proof and air-proof membrane is 100-10000 mm / s, and the moisture permeability is 100-5000 g / m². 2 / 24h.

[0022] As an optional technical solution in the first aspect, the air permeability of the moisture-proof and air-proof membrane is greater than that of the EPTFE membrane, and both the air permeability of the moisture-proof and air-proof membrane and the air permeability of the EPTFE membrane are greater than that of the composite material.

[0023] As an optional technical solution in the first aspect, the moisture permeability of the moisture-proof and air-proof membrane is less than that of the EPTFE membrane, and both the moisture permeability of the moisture-proof and air-proof membrane and the moisture permeability of the EPTFE membrane are greater than that of the composite material.

[0024] Optionally, the moisture-proof and air-proof membrane is one or more composites of PE film, PP film, PET film, PU film, and TPU film.

[0025] As an optional technical solution in the first aspect, a first nonwoven fabric is provided on the side of the EPTFE membrane away from the moisture-proof and air-proof membrane; the first nonwoven fabric is bonded and fixed to the EPTFE membrane in a certain area.

[0026] As an optional technical solution in the first aspect, the barrier layer is a second nonwoven fabric; and / or, a third nonwoven fabric is provided on the side of the moisture-proof and air-proof membrane away from the EPTFE membrane; the third nonwoven fabric is bonded and fixed to the moisture-proof and air-proof membrane in a certain area.

[0027] Optionally, the bonding and fixing method is adhesive bonding and / or thermal bonding and / or ultrasonic bonding.

[0028] Optionally, the first nonwoven fabric, the second nonwoven fabric, and the third nonwoven fabric are all water-repellent nonwoven fabrics; the water-repellent nonwoven fabric is a nonwoven fabric formed by one or more composites of hot air nonwoven fabric, meltblown nonwoven fabric, thermally rolled nonwoven fabric, SS spunbond nonwoven fabric, SMS nonwoven fabric, SMMS nonwoven fabric, and nonwoven fabric composed of multiple layers of S and multiple layers of M.

[0029] Secondly, an absorbent material includes a liquid-permeable layer, an absorbent layer, and a composite material as described in any of the above technical solutions, all stacked together; a moisture-proof and gas-proof membrane in the composite material is attached to the absorbent layer, or an EPTFE membrane in the composite material is attached to the absorbent layer; the unbonded area (including through holes) between the moisture-proof and gas-proof membrane and the EPTFE membrane constitutes a composite material interlayer space; the moisture discharged from the absorbent layer in the absorbent material includes moisture that penetrates the composite material to reach the outside and moisture that remains in the composite material interlayer space, and usually the amount of moisture discharged to the outside is greater than the amount of moisture contained in the composite material interlayer space.

[0030] As an alternative technical solution in the second aspect, the moisture-proof and gas-proof membrane is close to the absorption layer, with the end of the through hole with a larger diameter close to the EPTFE membrane and the end of the through hole with a smaller diameter close to the absorption layer; the liquid formed by the cooling of the moisture contained in the composite material interlayer space is absorbed by the absorption layer through the through holes.

[0031] Optionally, the EPTFE membrane in the composite material has a porous structure with a porosity of not less than 70% and a pore size range of 0.1 to 1.5 micrometers.

[0032] As an optional technical solution in the second aspect, the liquid-permeable layer is a nonwoven fabric formed by one or more composites of hot-air nonwoven fabric, hot-rolled nonwoven fabric, spunlace nonwoven fabric, and spunbond nonwoven fabric.

[0033] Optionally, the absorbent layer is formed by a composite of a superabsorbent polymer material and one or more of wood pulp fibers, nonwoven fabrics, fluffy cotton, and dust-free paper.

[0034] Furthermore, the particle size of the polymer absorbent material after absorbing moisture and swelling is larger than the pore size of the through-hole.

[0035] Optionally, when the moisture-proof and air-proof membrane of the composite material is located on the side close to the absorbent layer, a urine indicator adhesive is provided on the side of the moisture-proof and air-proof membrane close to the absorbent layer, and the urine indicator adhesive avoids the through hole.

[0036] Compared with the prior art, the technical solution provided by this utility model has the following advantages:

[0037] For the composite material proposed in this utility model, the airflow can first pass through the moisture-proof and air-proof membrane through the through holes and then penetrate the EPTFE membrane, or first penetrate the EPTFE membrane and then pass through the moisture-proof and air-proof membrane through the through holes. When the moisture vapor overflows instantaneously, the composite material has the function of blocking and retaining. By setting parameters such as the porosity, pore size, and density of the through holes on the moisture-proof and air-proof membrane, the composite material can have the advantages of high air permeability and low moisture permeability. Specifically, (1) except for the air-permeable and moisture-permeable area corresponding to the through holes, when the other areas of the EPTFE membrane that do not correspond to the through holes are all bonded and fixed to the non-perforated areas of the moisture-proof and air-proof membrane, the interlayer space of the composite material is only the perforated area where the through holes are set. For example, when the moisture-barrier membrane and the EPTFE membrane completely overlap, if the opening ratio of the moisture-barrier membrane is 30% (e.g., Demax = 0.25 mm, Demin = 0.15 mm), 70% of the EPTFE membrane area is blocked due to adhesion. In this case, the overall moisture permeability of the EPTFE membrane is lower than that of the moisture-barrier membrane, and the overall air permeability of the EPTFE membrane is also lower than that of the moisture-barrier membrane. Therefore, the moisture and air permeability of the composite material are determined by the air and moisture permeability of the EPTFE membrane corresponding to the perforations. The air and moisture permeability of the composite material also decreases to about 30% of that of the EPTFE membrane (70% of the area is blocked). By adjusting the EPTFE membrane manufacturing process (e.g., increasing the pore size), a high-permeability EPTFE base membrane (e.g., about 200 mm / s) can be prepared, satisfying the requirement that even with a 30% perforation area, the composite material still has high air permeability (e.g., about 60 mm / s) and low moisture permeability (e.g., about 2400 g / m²). 2(2) When a portion of the non-perforated area of ​​the moisture-proof and gas-proof membrane is bonded and fixed to a portion of the EPTFE membrane, the composite material interlayer space includes the perforated area and the remaining non-bonded area. For example, when the opening rate of the moisture-proof and gas-proof membrane is 15% (e.g., Demax = 0.25 mm, Demin = 0.15 mm), and the bonded area is 30%, then 30% of the pores in the air-permeable and moisture-permeable areas of the moisture-proof and gas-proof membrane and the EPTFE membrane are blocked. At this time, the overall moisture permeability of the EPTFE membrane is higher than that of the moisture-proof and gas-proof membrane, and the overall air permeability of the EPTFE membrane is lower than that of the moisture-proof and gas-proof membrane. Therefore, the moisture permeability of the composite material is determined by the remaining moisture permeability of the moisture-proof and gas-proof membrane, and the air permeability is determined by the remaining air permeability of the EPTFE membrane. The air permeability of the composite material is reduced to about 70% of that of the EPTFE membrane. The composite material can obtain a higher air permeability (e.g., about 60 mm / s) without increasing the air permeability of the EPTFE membrane. The moisture permeability of the composite material is reduced to about 70% of that of the moisture-proof and air-proof membrane. By adjusting the porosity, pore size, and distribution of the moisture-proof and air-proof membrane, composite materials with high air permeability (e.g., about 60 mm / s) and low moisture permeability (e.g., about 2400 g / m³) can be prepared. 2 / 24h, 0.9g / 10min).

[0038] This invention's composite material not only possesses the advantages of high air permeability and low moisture permeability, but also allows moisture to escape from the core, reducing the internal moisture content of the finished product without affecting the external environment. This is because the path of moisture penetrating the composite material from the core is either core—through-hole—EPTFE membrane—outside, or core—EPTFE membrane—through-hole—outside. The unbonded area (including perforated areas) between the moisture-proof and air-proof membrane and the EPTFE membrane constitutes the composite material interlayer space. The cold ambient temperature from the outside is conducted along the EPTFE membrane to the moisture-proof and air-proof membrane (or along the moisture-proof and air-proof membrane to the EPTFE membrane). Therefore, some moisture will condense into liquid within the composite material interlayer space. The moisture that penetrates the composite material to the outside and the moisture contained in the composite material interlayer space together constitute the total moisture permeability of the composite material. Since some moisture remains in the interlayer space and the absorbent core, the amount of moisture penetrating the absorbent material to the outside is reduced, preventing the outer garment from becoming damp. At the same time, since some moisture can reach the outside, the amount of moisture remaining in the absorbent material (especially the side close to the user's skin) is also reduced, which can reduce the feeling of stuffiness.

[0039] In addition, the moisture in the interlayer space is cooled and turns from water vapor into liquid water, which is stored between the moisture-proof and gas-proof membrane and the EPTFE membrane. However, this liquid will not remain in the interlayer space for a long time. This is because the present invention sets through holes on the moisture-proof and gas-proof membrane. The through holes are further designed as conical non-uniform surface through holes, with the larger hole surface (Demax) facing the EPTFE membrane and the smaller hole surface (Demin) facing the absorbent core. This design has several advantages compared to the straight through hole (Demax=Demin) and the smaller hole surface (Demin) facing the EPTFE membrane and the larger hole surface (Demax) facing the absorbent core: (1) Since the pore diameters at both ends of the through hole of the moisture-proof and gas-proof membrane are inconsistent, the structure of this product can be regarded as a non-uniform interface of water-repellent material. According to Young's Laplace equation, the additional pressure difference generated by this structure will cause the liquid to flow from the large hole to the small hole and block the liquid from flowing from the small hole to the large hole. Therefore, this design (larger pores facing the EPTFE membrane and smaller pores facing the absorbent core) allows the liquid remaining in the composite interlayer space to flow back to the absorbent core, preventing the liquid from covering the moisture-permeable and air-permeable micropores of the EPTFE membrane, and also avoiding the risk of leakage caused by the long-term wetting effect of residual liquid on the EPTFE membrane. (2) The absorbent material (such as SAP powder) in the absorbent core will expand after absorbing liquid. The absorbent material with increased outer diameter cannot pass through the small pores, and due to the influence of the interface effect, the liquid in the absorbent material is also difficult to penetrate the small pores and adhere to the inner surface of the EPTFE membrane, effectively reducing the wetting effect of liquid on the EPTFE membrane.

[0040] Furthermore, this invention achieves the advantages of high air permeability and low moisture permeability in the composite material simply by setting a thin, perforated moisture-barrier membrane, without increasing the basis weight or number of layers of the EPTFE membrane, thus controlling production costs. When the preferred moisture-barrier membrane is placed close to the absorbent layer, the areas of the EPTFE membrane not corresponding to the perforations are blocked by the non-perforated moisture-barrier membrane, resulting in less contact with moisture in these areas and a reduction in the overall moisture permeability of the composite material.

[0041] The composite material proposed in this invention is formed by laminating a moisture-proof and gas-proof membrane and an EPTFE membrane. Adding a perforated moisture-proof and gas-proof membrane layer effectively improves the composite material's resistance to compression and leakage after pressing. This is because when the composite material is subjected to force, the instantaneously applied external force acts directly on the perforated moisture-proof and gas-proof membrane surface. The moisture-proof and gas-proof membrane has high mechanical strength and strong resistance to deformation in the longitudinal, transverse, and perpendicular directions. When the weakened force acts on the EPTFE membrane surface, it is less likely to form stress concentration points on the EPTFE membrane surface, thus effectively protecting the internal fiber structure of the EPTFE membrane. Attached Figure Description

[0042] Figure 1This is a schematic diagram of a composite material formed by stacking a perforated moisture-proof and gas-proof membrane and an EPTFE membrane in one embodiment of this application.

[0043] Figure 2 This is a schematic diagram of a composite material formed by stacking a perforated moisture-proof and air-proof membrane, an EPTFE membrane, and a first nonwoven fabric in one embodiment of this application.

[0044] Figure 3 This is a schematic diagram of a composite material formed by stacking a third nonwoven fabric, a perforated moisture-proof and air-proof membrane, an EPTFE membrane, and a first nonwoven fabric in one embodiment of this application.

[0045] Figure 4 This is a schematic diagram of a composite material formed by stacking a perforated moisture-proof and air-proof membrane, a second non-woven fabric, an EPTFE membrane, and a first non-woven fabric in one embodiment of this application.

[0046] Figure 5 This is a schematic diagram of an absorbent article in one embodiment of this application;

[0047] Figure 6 A schematic diagram showing the application of urine indicator gel in the composite material of the absorbent article in one embodiment of this application;

[0048] Figure 7 This is a schematic diagram showing several placement positions of the urine indicator gel in the embodiments of this application;

[0049] Figure 8 A schematic diagram showing the application of urine indicator gel to the composite material of the absorbent article in another embodiment of this application;

[0050] Figure 9 This is a schematic diagram of the composite material of the absorbent article in another embodiment of this application;

[0051] Figure 10 These are schematic diagrams of several hole types for through holes in the embodiments of this application;

[0052] Figure 11 This is a schematic diagram of absorbent articles with several pore types in the embodiments of this application;

[0053] Figure 12 This is a schematic diagram of several absorbent materials when the EPTFE membrane is attached close to the absorbent layer in the embodiments of this application.

[0054] Explanation of the labels in the diagram:

[0055] Moisture-proof and air-proof membrane 101, EPTFE membrane 102, through-hole 103, adhesive area 104;

[0056] First nonwoven fabric 201, second nonwoven fabric 202, third nonwoven fabric 203;

[0057] Liquid permeable layer 301, water-retaining side 302, absorbent layer 303, urine indicator gel 304. Detailed Implementation

[0058] To further understand the content of this utility model, a detailed description of this utility model will be provided in conjunction with the accompanying drawings and embodiments.

[0059] The structures, proportions, and sizes illustrated in the accompanying drawings are solely for illustrative purposes and to aid those skilled in the art in understanding and reading the invention. They are not intended to limit the scope of the invention and therefore have no substantial technical significance. Any modifications to the structure, changes in proportions, or adjustments to size, provided they do not affect the effectiveness or purpose of the invention, should still fall within the scope of the technical content disclosed herein. Furthermore, terms such as "upper," "lower," "left," "right," and "middle" used in this specification are merely for clarity and not intended to limit the scope of implementation. Changes or adjustments to their relative relationships, without substantially altering the technical content, should also be considered within the scope of the invention's implementation.

[0060] This application proposes a composite material, such as Figure 1-4 As shown, the system includes a laminated EPTFE membrane 102 and a moisture-barrier membrane 101. The area of ​​the moisture-barrier membrane 101 when laid flat can be equal to, larger than, or smaller than the area of ​​the EPTFE membrane 102 when laid flat. That is, the moisture-barrier membrane 101 can completely cover the EPTFE membrane 102, or it can only cover the usable area of ​​the EPTFE membrane 102, where the usable area refers to the area of ​​the EPTFE membrane 102 that will come into contact with moisture.

[0061] When a user uses a disposable absorbent product containing the composite material described in this embodiment, a stacked EPTFE membrane 102 and a moisture-proof membrane 101 are provided in all areas of the absorbent product that come into contact with liquids or moisture. In areas that do not come into contact with liquids or moisture, one of the membranes, EPTFE membrane 102 or moisture-proof membrane 101, corresponds to these areas. Alternatively, a stacked EPTFE membrane 102 and moisture-proof membrane 101 can correspond to the areas that do not come into contact with liquids or moisture.

[0062] The EPTFE membrane 102 and the moisture-proof and gas-proof membrane 101 are bonded and fixed in a partial area. That is, one of the membranes, EPTFE membrane 102 and moisture-proof and gas-proof membrane 101, is not bonded and fixed to the other membrane entirely; rather, only a portion of the membrane surface of one membrane is bonded and fixed to a portion of the membrane surface of the other. This bonded area is called the bonding area 104. Besides the bonding area 104, the space between the moisture-proof and gas-proof membrane 101 and the EPTFE membrane 102 is called the interlayer space, which also includes the through-holes 103 provided in the moisture-proof and gas-proof membrane 101.

[0063] Using the EPTFE membrane surface as the projection surface and the direction perpendicular to the EPTFE membrane surface as the projection direction, the projection of the through-hole 103 along this projection direction is located on the projection surface. The through-hole 103 can be formed by mechanical drilling, ultrasonic drilling, or vacuum drilling processes. The cross-sectional shape of the through-hole perpendicular to its axial direction can be a regular shape such as a circle or polygon, or it can be other irregular shapes or patterns.

[0064] The moisture-proof and air-proof membrane 101 is provided with multiple through holes 103. Regarding the relationship between the diameters of the two ends of the through holes 103, the following implementation schemes are possible: (1) such as Figure 10 As shown in (a), the diameters at both ends of all through holes 103 are approximately equal; (2) as shown in Figure 10 As shown in (c), some through holes 103 have approximately equal diameters at both ends, while the diameter of one end of the remaining through holes 103 is larger than the diameter of the other end; (3) as shown in Figure 10 As shown in (b), the diameter of one end of all through holes 103 is larger than the diameter of the other end.

[0065] The orientation of the through hole 103 can be implemented in the following ways: (1) such as Figure 1-6 As shown in Figures 8-9, the larger end of the through-hole 103 faces the EPTFE membrane 102; (2) as shown in Figures 8-9. Figure 10 (b) As shown, the smaller end of the through-hole 103 faces the EPTFE membrane 102; (3) as shown Figure 10 As shown in (c), the larger end of some through holes 103 faces the EPTFE membrane 102, while the smaller end of the remaining through holes 103 faces the EPTFE membrane 102.

[0066] As an optional implementation, the air permeability of the moisture-proof and air-barrier membrane 101 is 100–10000 mm / s, for example, 200 mm / s, 600 mm / s, or 3000 mm / s, etc. The moisture permeability of the moisture-proof and air-barrier membrane 101 is 100–5000 g / m². 2 / 24h.

[0067] The inner diameter of the larger end of the through hole 103 is denoted as Demax, and the inner diameter of the smaller end of the through hole 103 is denoted as Demin, where 1 / 10 ≤ Demin / Demax < 1 / 1. The value of Demin ranges from 0.05mm to 1.0mm.

[0068] The through-holes 103 of the moisture-proof and air-proof membrane 101 have a density of (1-1000)*10 4 pcs / m 2 The open porosity of the moisture-proof and air-proof membrane 101 is 5% to 40%. The density and area of ​​the through holes 103 can be determined according to the application scenario of the composite material, thereby controlling the air permeability and moisture permeability of the composite material.

[0069] The function of the moisture-proof and gas-proof membrane 101 is to isolate moisture. In addition, it needs to allow some moisture to pass through the through-holes 103, while ensuring that the amount of moisture passing through the through-holes 103 is controllable. This prevents excessive moisture from being released to the outside while reducing moisture inside the core, thus minimizing a stuffy and humid feeling. The moisture-proof and gas-proof membrane 101 can be made of a polymer membrane, such as PE, PP, PET, PU, ​​or TPU, or a composite of multiple such membranes. When the material of the moisture-proof and gas-proof membrane 101 is PE, the membrane with through-holes can be called a PE perforated membrane.

[0070] The air permeability of the moisture-proof and gas-proof membrane 101 is greater than that of the EPTFE membrane 102, and both the air permeability of the moisture-proof and gas-proof membrane 101 and the EPTFE membrane 102 are greater than that of the composite material. Because it has through-holes 103 with a pore diameter of not less than 50 micrometers, airflow can pass through the through-holes of the moisture-proof and gas-proof membrane 101, resulting in a higher air permeability of the perforated membrane. For the composite material, since the through-holes correspond to the EPTFE membrane, and other areas of the EPTFE membrane are blocked by the moisture-proof and gas-proof membrane 101, the overall air permeability of the composite material is lower than that of the moisture-proof and gas-proof membrane 101 and the EPTFE membrane 102 when placed individually.

[0071] The moisture permeability of the moisture-proof and gas-proof membrane 101 is less than that of the EPTFE membrane 102, and both the moisture permeability of the moisture-proof and gas-proof membrane 101 and the EPTFE membrane 102 are greater than that of the composite material. Because some areas of the composite material are blocked by the non-perforated areas of the moisture-proof and gas-proof membrane 101, and the perforated areas of the moisture-proof and gas-proof membrane 101 are blocked by the EPTFE membrane, the overall moisture permeability of the composite material is lower than that of the moisture-proof and gas-proof membrane 101 and the EPTFE membrane 102 when placed individually.

[0072] Regarding the specific structure of the composite material formed by laminating the moisture-proof and air-proof membrane 101 and the EPTFE membrane 102, in one embodiment, such as... Figure 1 , 2As shown, the moisture-proof and gas-proof membrane 101 is in direct contact with the EPTFE membrane 102. In another embodiment, such as... Figure 3-4 As shown, a barrier layer is provided between the moisture-proof and air-proof membrane 101 and the EPTFE membrane 102.

[0073] Specifically, such as Figure 2-4 As shown, a first nonwoven fabric 201 is disposed on the side of the EPTFE membrane 102 opposite to the moisture-proof and gas-proof membrane 101. The first nonwoven fabric 201 is bonded and fixed to the EPTFE membrane 102 in a partial area. It should be noted that the bonding area between the first nonwoven fabric 201 and the EPTFE membrane 102 can coincide with the bonding area 104 (the bonding point between the moisture-proof and gas-proof membrane 101 and the EPTFE membrane 102), or the bonding area 104 can be staggered.

[0074] The barrier layer can be a second nonwoven fabric 202. Additionally, a third nonwoven fabric 203 can also be provided on the side of the moisture-proof and gas-proof membrane 101 facing away from the EPTFE membrane 102. The third nonwoven fabric 203 is bonded and fixed to the moisture-proof and gas-proof membrane 101 in a partial area. It should be noted that the bonding area between the third nonwoven fabric 203 and the moisture-proof and gas-proof membrane 101 can coincide with the bonding area 104 (the bonding point between the moisture-proof and gas-proof membrane 101 and the EPTFE membrane 102), or it can be offset from the bonding area 104 (e.g.,...). Figure 3 (As shown).

[0075] Composite materials can have the following structures:

[0076] (1) A two-layer composite material formed by laminating a moisture-proof and air-proof membrane 101 and an EPTFE membrane 102; adhesive bonding and / or thermal bonding can be used to achieve bonding and fixation in some areas;

[0077] (2) A three-layer composite material formed by stacking a moisture-proof and gas-proof membrane 101, an EPTFE membrane 102, and a first nonwoven fabric 201. The three layers can be bonded sequentially in the same or different areas. Alternatively, the EPTFE membrane 102 and the first nonwoven fabric 201 can be thermally bonded into two layers first, and then the moisture-proof and gas-proof membrane 101 can be adhesively bonded to these two layers to form a three-layer material.

[0078] (3) A three-layer composite material formed by stacking a moisture-proof and air-proof membrane 101, a second non-woven fabric 202, and an EPTFE membrane 102. The three layers can be bonded sequentially in the same or different areas. Alternatively, the moisture-proof and air-proof membrane 101 and the second non-woven fabric 202 can be glued together to form two layers, and then the EPTFE membrane 102 can be thermally bonded to these two layers to form a three-layer material.

[0079] (4) A four-layer composite material formed by stacking moisture-proof and air-proof membrane 101, second nonwoven fabric 202, EPTFE membrane 102, and first nonwoven fabric 201. The three layers can be bonded sequentially in the same or different areas. Alternatively, the moisture-proof and air-proof membrane 101 and second nonwoven fabric 202 can be composited into two layers first, and then EPTFE membrane 102 and first nonwoven fabric 201 can be composited sequentially. Or the moisture-proof and air-proof membrane 101 and second nonwoven fabric 202 can be composited into two layers, and EPTFE membrane 102 and first nonwoven fabric 201 can be composited into two layers, and then composited. Or the second nonwoven fabric 202, EPTFE membrane 102, and first nonwoven fabric 201 can be composited into three layers, and then the moisture-proof and air-proof membrane 101 can be composited with the three layers.

[0080] (5) A three-layer composite material formed by stacking a third nonwoven fabric 203, a moisture-proof and air-proof membrane 101, and an EPTFE membrane 102; the three layers can be bonded sequentially in the same or different areas. Alternatively, two adjacent layers can be laminated first, and then the third layer can be laminated.

[0081] (6) A four-layer composite material formed by stacking the third nonwoven fabric 203, the moisture-proof and air-proof membrane 101, the EPTFE membrane 102, and the first nonwoven fabric 201; the four layers can be bonded sequentially in the same or different areas. Alternatively, two or three adjacent layers can be bonded first, and then the remaining layers can be bonded.

[0082] (7) A four-layer composite material formed by stacking the third nonwoven fabric 203, the moisture-proof and air-proof membrane 101, the second nonwoven fabric 202, and the EPTFE membrane 102; the four layers can be bonded sequentially in the same or different areas. Alternatively, two or three adjacent layers can be bonded first, and then the remaining layers can be bonded.

[0083] (8) A five-layer composite material formed by stacking the third nonwoven fabric 203, the moisture-proof and air-proof membrane 101, the second nonwoven fabric 202, the EPTFE membrane 102, and the first nonwoven fabric 201; the five layers of materials can be bonded sequentially in the same or different areas. Alternatively, two, three, or four adjacent layers of materials can be bonded together first, and then the remaining materials can be bonded together.

[0084] It should be noted that the bonding areas of each layer can be in the same location, or the bonding areas of each layer can be in different locations. The bonding areas of some layers can be in the same location, while the bonding areas of other layers are in different locations (e.g., ...). Figure 3 (As shown).

[0085] If thermal lamination is used, such as when the moisture-proof and gas-proof membrane 101 is a PE perforated membrane, due to the low melting point of polyethylene, overall bonding can be achieved at a lower temperature, with an interlayer bonding strength greater than 5 kgf. The PE perforated membrane is soft and can be thermally laminated at low temperatures, minimizing the risk of damage to the EPTFE membrane from the raised edges of the thermal lamination, thus providing high protection for the EPTFE membrane.

[0086] If adhesive bonding is used, for example, when the moisture-proof and air-barrier membrane 101 is a PE perforated membrane, the existing production process and parameters can be used to stably produce the PE perforated membrane when adding it to the existing laminated material structure of the second nonwoven fabric 202 and EPTFE membrane 102, or the existing laminated material structure of the second nonwoven fabric 202, EPTFE membrane 102, and first nonwoven fabric 201. Since the PE perforated membrane is partially separated from other composite materials (i.e., only partially bonded), the PE perforated membrane does not undergo the original composite process, thus avoiding any impact on air permeability. In this case, the PE perforated membrane can achieve higher air permeability with a lower open-cell ratio, while the lower open-cell ratio results in lower moisture permeability and higher hydrostatic pressure. PE perforated film can replace the outer wrapping layer of the absorbent core in absorbent products such as diapers. At this time, the PE perforated film is then glued together with the original second nonwoven fabric 202 and EPTFE film 102 laminated material structure, or the original second nonwoven fabric 202, EPTFE film 102 and first nonwoven fabric 201 laminated material structure. This will not add extra workstations to the diaper equipment and reduce the manufacturer's usage costs.

[0087] It should be noted that the above-mentioned bonding and fixing methods are not limited to hot pressing and adhesive bonding; existing technologies such as ultrasonic bonding are also applicable to this application.

[0088] As an optional implementation, the first nonwoven fabric 201, the second nonwoven fabric 202, and the third nonwoven fabric 203 all have air permeability, and their air permeability is greater than that of the EPTFE membrane 102.

[0089] The first nonwoven fabric 201, the second nonwoven fabric 202, and the third nonwoven fabric 203 are all water-repellent nonwoven fabrics. The water-repellent nonwoven fabric can be a composite nonwoven fabric formed by one or more of the following: hot air nonwoven fabric, meltblown nonwoven fabric, thermally bonded nonwoven fabric, SS spunbond nonwoven fabric, SMS nonwoven fabric, SMMS nonwoven fabric, and nonwoven fabric composed of multiple layers of S and multiple layers of M.

[0090] In one embodiment, this application also proposes an absorbent material, which can be a diaper, sanitary napkin, menstrual panties, incontinence pads, nursing pads, diaper changing pads, etc. The absorbent material can be a disposable absorbent material, comprising a liquid-permeable layer 301, an absorbent layer 303, and the aforementioned composite material, all stacked together. The moisture-proof and air-proof membrane 101 in the composite material is attached close to the absorbent layer 303, or the EPTFE membrane 102 in the composite material can also be attached close to the absorbent layer 303.

[0091] In other words, the composite material in absorbent products can be implemented in the following ways:

[0092] (1) As Figure 11 As shown in (a), the moisture-proof and air-proof membrane 101 is close to the absorption layer 303, and the diameters of all through holes 103 are approximately equal at both ends.

[0093] (2) The moisture-proof and air-proof membrane 101 is close to the absorption layer 303. Some of the through holes 103 have approximately equal diameters at both ends, while the diameter of one end of the remaining through holes 103 is larger than that of the other end. The end with the larger diameter faces the EPTFE membrane 102, and the end with the smaller diameter faces the absorption layer 303.

[0094] (3) The moisture-proof and air-proof membrane 101 is close to the absorber layer 303. Some through holes 103 have roughly equal diameters at both ends, while the diameter of one end of the remaining through holes 103 is larger than that of the other end. The larger diameter end faces the absorber layer 303, and the smaller diameter end faces the EPTFE membrane 102.

[0095] (4) Figure 5-6 As shown in Figures 8-9, the moisture-proof and air-proof membrane 101 is close to the absorber layer 303. All the through holes 103 have a larger diameter at one end than at the other end. The end with the larger diameter faces the EPTFE membrane 102, and the end with the smaller diameter faces the absorber layer 303.

[0096] (5) Figure 11 As shown in (c), the moisture-proof and air-proof membrane 101 is close to the absorption layer 303. The diameter of one end of all the through holes 103 is larger than the diameter of the other end. The end with the smaller diameter faces the EPTFE membrane 102, and the end with the larger diameter faces the absorption layer 303.

[0097] (6) Figure 12 As shown in (a), the EPTFE membrane 102 is close to the absorber layer 303, and the diameters of all through holes 103 are approximately equal at both ends.

[0098] (7) The EPTFE membrane 102 is close to the absorber layer 303. Some of the through holes 103 have approximately equal diameters at both ends. The diameter of one end of the remaining through holes 103 is larger than that of the other end. The end with the larger diameter faces the EPTFE membrane 102, and the end with the smaller diameter faces the absorber layer 303.

[0099] (8) The EPTFE membrane 102 is close to the absorber layer 303. Some through holes 103 have roughly equal diameters at both ends, while the diameter of one end of the remaining through holes 103 is larger than that of the other end. The larger diameter end faces the absorber layer 303, and the smaller diameter end faces the EPTFE membrane 102.

[0100] (9) The EPTFE membrane 102 is close to the absorber layer 303. The diameter of one end of all the through holes 103 is larger than the diameter of the other end. The end with the larger diameter faces the EPTFE membrane 102, and the end with the smaller diameter faces the absorber layer 303.

[0101] (10) such as Figure 12 As shown in (b), the EPTFE membrane 102 is close to the absorber layer 303. The diameter of all the through holes 103 is larger at one end than at the other end. The end with the larger diameter faces the absorber layer 303, and the end with the smaller diameter faces the EPTFE membrane 102.

[0102] Of course, the orientation of the through hole is not limited to the above schemes, such as... Figure 11 (c) Figure 12 As shown in (c), the through holes provided on the moisture-proof and air-proof membrane 101 can be a part with approximately equal diameters at both ends, a part with the larger diameter end facing the absorption layer 303 and the smaller diameter end facing the EPTFE membrane 102, and another part with the larger diameter end facing the EPTFE membrane 102 and the smaller diameter end facing the absorption layer 303.

[0103] like Figure 5 , 6 As shown in Figures 8 and 9, only a portion of the composite material's laminated structure is shown. The laminated structures of other composite materials not shown in the figures are applicable to the disposable absorbent products in this embodiment.

[0104] The unbonded area between the moisture-proof and air-proof membrane 101 and the EPTFE membrane 102 constitutes a composite material interlayer space, which also includes the through-hole 103. The moisture discharged from the absorbent layer in the absorbent product includes moisture that penetrates the composite material to reach the outside and moisture that remains in the composite material interlayer space. The amount of moisture discharged to the outside is greater than the amount of moisture contained in the composite material interlayer space.

[0105] As a preferred embodiment, the moisture-proof and gas-proof membrane 101 in the composite material is positioned close to the absorbent layer 303, with the larger pore diameter end of the moisture-proof and gas-proof membrane 101 close to the EPTFE membrane 102 and the smaller pore diameter end close to the absorbent layer 303. Due to the interface effect, liquid does not easily flow from the small pores to the large pores, but easily flows back from the large pores to the small pores. Therefore, positioning the larger pore diameter end of the through-hole 103 close to the EPTFE membrane can prevent liquid from flowing into the EPTFE membrane 102, and also allows the liquid remaining in the composite material interlayer to flow back to the absorbent layer 303 through reverse absorption. This prevents the liquid from covering the moisture-permeable and gas-permeable micropores of the EPTFE membrane 102, and also avoids the risk of leakage caused by the prolonged wetting of the EPTFE membrane 102 by residual liquid.

[0106] Disposable absorbent products can also be equipped with a water-blocking side 302. The process of setting up the water-blocking side 302 is relatively mature in the existing technology, and will not be described in detail here.

[0107] Optionally, the liquid-permeable layer 301 is a nonwoven fabric formed by one or more composites of hot-air nonwoven fabric, thermally rolled nonwoven fabric, spunlace nonwoven fabric, and spunbond nonwoven fabric. The absorbent layer 303 can be formed by one or more composites of a superabsorbent polymer material and wood pulp fiber, nonwoven fabric, fluffy cotton, and dust-free paper. The superabsorbent polymer material can be SAP absorbent powder or other materials in the prior art.

[0108] The particle size of the superabsorbent polymer (SAP) material after absorbing moisture and expanding is larger than the pore size of the through-hole 103. This prevents the absorbed material from contacting the EPTFE membrane 102, reducing the possibility of permeation. For example, if the diameter of the SAP superabsorbent powder increases from 0.2 mm to 2.0 mm after absorbing liquid, the pore size of the processed through-hole 103 will be less than 2.0 mm. In this case, the SAP superabsorbent powder absorbing liquid will be blocked by the moisture-proof and air-proof membrane 101, making it difficult for the liquid contained within the SAP superabsorbent powder to enter the EPTFE membrane 102, effectively reducing the wetting effect of the liquid on the EPTFE membrane 102.

[0109] In one alternative embodiment, the disposable absorbent product may be provided with a urine indicator gel 304. The urine indicator gel may also be a humidity-indicating composite material, a water-based adhesive or a hot-melt adhesive, having a first color when dry and a second color when wet, the second color being different from the first color.

[0110] like Figure 6 As shown, when the moisture-proof and gas-proof membrane 101 of the composite material is located on the side close to the absorbent layer 303, a urine indicator gel 304 can be applied to the membrane surface on the side of the moisture-proof and gas-proof membrane 101 close to the absorbent layer 303. At this time, as... Figure 7 (a) Figure 7 As shown in (b), the urine indicator gel 304 is strip-shaped and avoids the through-hole 303. It can also be as follows: Figure 7 As shown in (c), the urine indicator gel 304 is in the shape of a line segment and avoids the through hole 303.

[0111] Existing disposable absorbent products use EPTFE composite materials for the breathable yet liquid-impermeable bottom layer, often composed of non-woven fabric and an EPTFE membrane. Both the untreated non-woven fabric and EPTFE membrane possess strong oleophilic properties. This is because non-woven fabric has a porous structure composed of interwoven fine fibers, with uniform fiber distribution and high porosity. Oil molecules easily adhere to the surface or interior of the non-woven fabric due to intermolecular forces. EPTFE membranes, in addition to a similar porous structure to non-woven fabrics, also possess stronger oil absorption capacity due to their manufacturing process. This combined oil absorption capacity can cause polar and strongly hydrophilic components in urine indicator gels to penetrate the non-woven fabric and EPTFE membrane under stress, leading to a risk of leakage. Research suggests that EPTFE membranes can be modified to repel polar and strongly hydrophilic components in urine indicator gels. However, on the one hand, the cost of oil-repellent modification of EPTFE membranes is very high, ranging from approximately 10 to 100 yuan per square meter. This excessive cost hinders the market promotion and large-scale use of the product. On the other hand, the oil-repellent modification technology for EPTFE membranes is still imperfect, and the oil-repellent performance of modified EPTFE membranes is unstable, making it difficult for the industry to achieve low-cost and stable production at present.

[0112] Therefore, in this embodiment, a moisture-proof and air-proof membrane 101 is set up, and the urine indicator adhesive 304 is applied to the non-porous area on the moisture-proof and air-proof membrane 101. This prevents polar and strongly hydrophilic components in the urine indicator adhesive from directly contacting the EPTFE membrane 102. This achieves the urine indicator color-changing function without significantly affecting the air permeability of the composite material, thus effectively solving the risk of urine indicator adhesive leakage.

[0113] In one embodiment, this application proposes a method for manufacturing a hot-pressed composite material consisting of a PE perforated film, a second nonwoven fabric, an EPTFE film, and a first nonwoven fabric, comprising the following steps: The PE perforated film, the second nonwoven fabric, the EPTFE film, and the first nonwoven fabric undergo an electrostatic lamination process to form a non-adhesive composite material consisting of the PE film, the nonwoven fabric, the EPTFE film, and the nonwoven fabric stacked sequentially. This composite material is then pressed together by a patterned roller and a smooth roller using an unwinding device, and finally fixed by hot-pressing. The bonding temperature is 110℃ / 140℃, the bonding pressure is 5-8 kg, and the winding speed is 40 m / min. The hot-pressing production process can be found in Chinese patent document CN116808270A.

[0114] In one embodiment, this application proposes a method for manufacturing a composite material consisting of a PE perforated film, an EPTFE film, and a nonwoven fabric, comprising the following steps: The EPTFE film and a first nonwoven fabric undergo an electrostatic lamination process to form a non-adhesive composite body consisting of the EPTFE film and the nonwoven fabric stacked sequentially. This composite body is pressed together by a patterned roller and a smooth roller using an unwinding device, and then fixed by hot-pressing adhesion. The adhesion temperature is 150℃ / 150℃, the adhesion pressure is 5-8 kg, and the winding speed is 40 m / min. The hot-pressing production process can be referenced in Chinese patent document CN116808270A. The composite body and the PE perforated film can be unwound separately into a PUR hot melt adhesive machine. The PUR hot melt adhesive is transferred to the unperforated area of ​​the PE perforated film by a scraper roller, and then bonded to the EPTFE film to achieve effective adhesion. The scraper roller can control the adhesive application area and amount. The adhesive application amount is 1.0 gsm, the PUR hot melt adhesive temperature is 90℃, and the winding speed is 80 m / min.

[0115] Example 1: As Figure 1 As shown, the composite material is an adhesive composite consisting of a perforated PE membrane and an EPTFE membrane stacked sequentially. The hot melt adhesive is PUR hot melt adhesive, with an application temperature of 90℃ and an application rate of 1 g / m³. 2 The adhesive coating area is the non-perforated area of ​​the PE perforated membrane. The PE perforated membrane is the same size as the EPTFE membrane. Disposable absorbent products such as... Figure 5 As shown, the permeable layer has a basis weight of 40 g / m³. 2 Hydrophilic hot air nonwoven fabric, absorbent layer is 400g / m² 2 The composite core has a water-blocking side weight of 22g / m². 2 Water-repellent hot air nonwoven fabric. The composite material is laid flat below the absorbent layer, with a perforated PE membrane on the side closest to the absorbent layer.

[0116] The PE perforated membrane has a basis weight of 18 g / m³. 2 Air permeability 2300mm / s, pore density 600×10 4 / m 2 The porosity is 30%, the maximum equivalent diameter (Demax) of the through-hole is 0.25 mm, and the minimum equivalent diameter (Demin) of the through-hole is 0.15 mm. The larger diameter end of the through-hole faces the EPTFE membrane, and the smaller diameter end faces the absorber core.

[0117] The EPTFE membrane has a basis weight of 2.0 g / m³. 2 Air permeability 100mm / s, moisture permeability 4000g / m² 2 / 24h.

[0118] Example 7 Figure 11 As shown in (c), its only difference from Example 1 is that the smaller end of the through hole faces the EPTFE membrane.

[0119] Example 8 Figure 11 As shown in (a), the only difference between it and Example 1 is that the PE perforated membrane used is a through-hole type, and the basis weight of the PE perforated membrane is 18 g / m³. 2 Air permeability 3000mm / s, open pore density 600×10 4 / m 2 The aperture ratio is 30%, and the equivalent diameter De of the through hole is 0.25mm.

[0120] The only difference between Comparative Example 3 and Example 1 is that the liquid-impermeable bottom layer of the diaper is a conventional PE film with added calcium carbonate. The basis weight of the PE film is 22 g / m³. 2 The air permeability is 0.2 mm / s.

[0121] Performance tests were conducted on Examples 1, 7, 8, Comparative Example 3, and Comparative Example 7, and the results are shown in Table 1.

[0122]

[0123] Table 1

[0124] Table 1 shows that, while ensuring no leakage in actual application, adding a perforated PE membrane can significantly improve the moisture permeability and leak-proof rating of the finished product. Compared to PE calcium carbonate breathable membrane, the air permeability can be increased by approximately 100 times, and compared to conventional EPTFE composite materials, the moisture permeability can be reduced by approximately 50%. It can also be concluded that, all other factors being equal, the pore shape and orientation of the perforated PE membrane have a direct impact on the air and moisture permeability of the finished product.

[0125] Example 2: As Figure 1 As shown, the composite material is a thermoplastic composite consisting of a perforated PE membrane and an EPTFE membrane stacked sequentially. After the laminate of the perforated PE membrane and EPTFE membrane is heated at low temperature by a smooth roller, the non-perforated areas of the PE membrane adhere to the EPTFE membrane, forming a strong bond. The heating temperature is 100℃ / 100℃, and the pressure is 5kg. The ratio of adhered area to unadheded area is 7:3. The perforated PE membrane and the EPTFE membrane are the same size. Disposable absorbent products are shown below. Figure 5 As shown, the permeable layer has a basis weight of 40 g / m³. 2 Hydrophilic hot air nonwoven fabric, absorbent layer is 400g / m² 2 The composite core has a water-blocking side weight of 22g / m². 2 Water-repellent hot air nonwoven fabric. The composite material is laid flat below the absorbent layer, with a perforated PE membrane on the side closest to the absorbent layer.

[0126] The PE perforated membrane has a basis weight of 18 g / m³. 2 Air permeability 2300mm / s, pore density 600×10 4 / m 2The porosity is 30%, the maximum equivalent diameter of the through-hole (Demax) is 0.25 mm, the minimum equivalent diameter of the through-hole (Demin) is 0.15 mm, and the moisture permeability is 2900 g / m². 2 / 24h. The larger pore diameter end faces the EPTFE membrane, and the smaller pore diameter end faces the absorber core.

[0127] The EPTFE membrane has a basis weight of 2.0 g / m³. 2 Air permeability 100mm / s, moisture permeability 4000g / m² 2 / 24h, hydrostatic pressure 2.0kPa.

[0128] The only difference between Comparative Example 4 and Example 2 is the specification of the EPTFE membrane used. The EPTFE membrane basis weight is 2.0 g / m³. 2 Air permeability 150mm / s, moisture permeability 4000g / m² 2 / 24h, hydrostatic pressure 1.2kPa. Performance tests were conducted on Example 2 and Comparative Example 4, and the results are shown in Table 2.

[0129]

[0130] Table 2

[0131] Table 2 shows that, while ensuring no leakage in actual applications and keeping the PE perforated membrane specifications unchanged, higher air permeability can be achieved by adjusting the air permeability of the EPTFE membrane without increasing moisture permeability. However, since the air permeability of the EPTFE membrane is related to the hydrostatic pressure and the pore size and porosity of the EPTFE membrane, based on the hydrostatic pressure of 4 kPa for the PE calcium carbonate breathable membrane and actual usage conditions, in this application, the porosity of the EPTFE membrane is not less than 70%, and the pore size range is 0.1–1.5 micrometers.

[0132] The only difference between Comparative Example 5 and Example 2 is the porosity of the PE perforated membrane used. The basis weight of the PE perforated membrane is 18 g / m³. 2 Air permeability 1800mm / s, pore density 300×10 4 / m 2 The porosity is 15%, the maximum equivalent diameter of the through-hole (Demax) is 0.25 mm, the minimum equivalent diameter of the through-hole (Demin) is 0.15 mm, and the moisture permeability is 2700 g / m². 2 / 24h. The larger pore diameter end of the through-hole faces the EPTFE membrane, and the smaller pore diameter end faces the absorber core. Performance tests were conducted on Example 2 and Comparative Example 5, and the results are shown in Table 3.

[0133]

[0134] Table 3

[0135] Table 3 shows that, assuming no leakage in actual application, and all other conditions are equal, increasing the open-cell ratio of the PE perforated membrane leads to increased moisture permeability, while decreasing the open-cell ratio leads to decreased air permeability. Since the breathable underlayer requires a certain level of air and moisture permeability, the open-cell ratio of the PE perforated membrane has upper and lower limits. Considering the difficulty of EPTFE membrane production and the acceptable air and moisture permeability for customers, in this application, the upper limit of the open-cell ratio of the PE perforated membrane is 40%, and the lower limit is 5%.

[0136] The porosity of PE perforated membranes is related to pore size and pore density, and the pore size should not be too large. This is because excessively large local pore sizes will lead to high moisture permeability in that area, which does not meet the low moisture permeability requirement of the finished product. Considering the difficulty of PE membrane perforation process and air permeability requirements, and from the perspective of acceptable moisture permeability for customers, in this application, the smaller end diameter Demin of the PE perforated membrane is ranged from 0.05mm to 0.5mm.

[0137] Example 3: As Figure 3 As shown, the composite material is a hot-pressed composite material consisting of a perforated PE membrane, a non-woven fabric, an EPTFE membrane, and another non-woven fabric layered sequentially. The press lines are all 1.5 mm wide and spaced 3.5 mm apart, with a press area to non-press area ratio of 3:7. The perforated PE membrane, EPTFE membrane, and non-woven fabric are all the same size. Disposable absorbent materials are not shown in the diagram; the permeable layer has a basis weight of 40 g / m³. 2 Hydrophilic hot air nonwoven fabric, absorbent layer is 400g / m² 2 The composite core has a water-blocking side weight of 22g / m². 2 Water-repellent hot air nonwoven fabric. The composite material is laid flat below the absorbent layer, with a perforated PE membrane on the side closest to the absorbent layer.

[0138] The PE perforated membrane has a basis weight of 23 g / m³. 2 Air permeability 2300mm / s, pore density 600×10 4 / m 2 The porosity is 30%, the maximum equivalent diameter of the through-hole (Demax) is 0.25 mm, the minimum equivalent diameter of the through-hole (Demin) is 0.15 mm, and the moisture permeability is 2900 g / m². 2 / 24h. The larger pore diameter end faces the EPTFE membrane, and the smaller pore diameter end faces the absorber core.

[0139] The EPTFE membrane has a basis weight of 2.0 g / m³. 2 Air permeability 100mm / s, moisture permeability 4000g / m² 2 / 24h.

[0140] The only difference between Comparative Example 7 and Example 3 is that the liquid-impermeable bottom layer of the diaper is a hot-pressed composite material consisting of layers of non-woven fabric, EPTFE membrane, and another layer of non-woven fabric. The EPTFE membrane has a basis weight of 2.0 g / m³. 2 Air permeability 100mm / s, moisture permeability 4000g / m² 2 / 24h (3.0g / 10min). All nonwoven fabrics are SSMMS nonwoven fabrics with a basis weight of 7g / m². 2 .

[0141] Performance tests were conducted on Example 3 and Comparative Example 7, and the results are shown in Table 4.

[0142]

[0143] Table 4

[0144] As shown in Table 4, under the premise of ensuring no leakage in actual product applications, the structure formed by stacking PE perforated membrane, non-woven fabric, EPTFE membrane, and non-woven fabric can significantly improve the moisture permeability and anti-leakage level of the finished product and also achieve higher air permeability, but it will slightly increase the moisture permeability. Therefore, under this structure, the opening rate of PE perforated membrane can be reduced to reduce the moisture permeability.

[0145] Example 4: Figure 8 As shown, the composite material is a composite material consisting of a PE perforated film, a non-woven fabric, an EPTFE film, and another non-woven fabric layered sequentially. The non-woven fabric, EPTFE film, and non-woven fabric are first hot-pressed to form a three-layer composite material with consistent 1.5mm width and 3.5mm spacing between the press lines. The ratio of the pressed area to the unpressed area is 3:7. The PE perforated film is then bonded to the three-layer composite material using hot melt adhesive, ultimately forming a four-layer composite material. The PE perforated film, EPTFE film, and non-woven fabric are all the same size. The liquid-permeable layer has a basis weight of 40g / m³. 2 Hydrophilic hot air nonwoven fabric, absorbent layer is 400g / m² 2 The composite core has a water-blocking side weight of 22g / m². 2 Water-repellent hot-air nonwoven fabric. The composite material is laid flat below the absorbent layer, with a perforated PE membrane on the side closest to the absorbent layer. The PE membrane facing the absorbent layer is coated with a urine indicator adhesive, which consists of three 2mm wide strips, each 250mm long.

[0146] The PE perforated membrane has a basis weight of 14 g / m³. 2 Air permeability 2000mm / s, pore density 300×10 4 / m 2 The porosity is 15%, the minimum equivalent diameter of the through-hole (Demin) is 0.15 mm, the maximum equivalent diameter of the through-hole (Demax) is 0.25 mm, and the moisture permeability is 2900 g / m³. 2 / 24h. The larger pore diameter end faces the EPTFE membrane, and the smaller pore diameter end faces the absorber core. The EPTFE membrane basis weight is 2.0 g / m³. 2 The air permeability is 100mm / s. The nonwoven fabric is SSMMS nonwoven fabric with a basis weight of 7g / m³. 2 The hot melt adhesive is EVA pressure-sensitive type, with an application rate of 1g / m². 2 The application width is 2mm and the spacing is 3mm.

[0147] A urine indicator adhesive is applied to the side of the PE perforated membrane facing the absorbent layer. The urine indicator adhesive 12 consists of 3 adhesive strips with a width of 2 mm and a length of 250 mm.

[0148] The only difference between Comparative Example 9 and Example 4 is that the liquid-impermeable bottom layer of the diaper is a three-layer thermo-pressed composite material consisting of non-woven fabric, EPTFE film, and non-woven fabric stacked sequentially. A urine indicator adhesive is coated on the non-woven fabric facing the core; the adhesive consists of 2 mm wide strips, each 250 mm long. The EPTFE film has a basis weight of 2.0 g / m³. 2 The air permeability is 100mm / s. All nonwoven fabrics are SSMMS nonwoven fabrics with a basis weight of 7g / m². 2 .

[0149] The only difference between Comparative Example 10 and Example 4 is that the liquid-impermeable bottom layer of the diaper is a conventional PE film with added calcium carbonate. A urine indicator adhesive is coated on the side of the conventional PE film facing the absorbent core. The urine indicator adhesive consists of three adhesive strips with a width of 2 mm and a length of 250 mm.

[0150] Performance tests were conducted on Example 4, Comparative Example 9, and Comparative Example 10, and the results are shown in Table 5.

[0151]

[0152] Table 5

[0153] Table 5 shows that, while ensuring no leakage in practical applications, adding a perforated PE membrane to the existing composite material of nonwoven fabric, EPTFE membrane, and nonwoven fabric layers prevents leakage even with the addition of urine indicator adhesive. This solves the problem of not being able to coat the composite material with urine indicator adhesive. Furthermore, reducing the porosity of the PE perforated membrane does not reduce air permeability, resulting in low moisture permeability and good leak resistance.

[0154] Example 5: A disposable absorbent product comprises a liquid-permeable layer, an absorbent layer, and a moisture-proof and gas-proof membrane stacked sequentially, as well as a composite material formed by hot-pressing nonwoven fabric, EPTFE membrane, and nonwoven fabric stacked sequentially. The press lines are of uniform width, 2 mm, and spaced 5 mm apart. The ratio of pressed area to unpressed area is 2:3. The EPTFE membrane and nonwoven fabric are of the same size. Each layer is formed into a single unit by lamination and bonding from top to bottom. The disposable absorbent product also includes a water-repellent side. The liquid-permeable layer has a basis weight of 40 g / m³. 2 Hydrophilic hot air nonwoven fabric, absorbent layer is 400g / m² 2 The composite core has a water-blocking side weight of 22g / m². 2 Water-repellent and heat-resistant nonwoven fabric. The length of the moisture-proof and air-proof perforated membrane is the same as that of the absorbent layer, and the width is to wrap around or partially wrap around the absorbent layer as required.

[0155] The moisture-proof and air-proof perforated membrane is coated with urine indicator adhesive on the absorbent layer side. The urine indicator adhesive consists of three adhesive strips with a width of 2 mm and a length of 250 mm.

[0156] The moisture-proof and air-proof membrane is a perforated PE membrane with a basis weight of 14 g / m³. 2 Air permeability 2000mm / s, pore density 300×10 4 / m 2 The porosity is 15%, the minimum equivalent diameter of the through-hole (Demin) is 0.15 mm, the maximum equivalent diameter of the through-hole (Demax) is 0.25 mm, and the moisture permeability is 2700 g / m². 2 / 24h. The larger pore diameter end faces the EPTFE membrane, and the smaller pore diameter end faces the absorber core. The EPTFE membrane basis weight is 2.0 g / m³. 2 The air permeability is 100mm / s. The nonwoven fabric is SSMMS nonwoven fabric with a basis weight of 7g / m³. 2 .

[0157] The performance of the product from Example 5 was tested, and the results are shown in Table 6.

[0158]

[0159] Table 6

[0160] As can be seen from Table 6, while ensuring that there is no leakage in actual product applications, wrapping the absorbent layer with a PE perforated membrane can reduce the material usage of the composite core of the absorbent layer and reduce the material usage of the PE perforated membrane, which is beneficial to reducing production costs and can also achieve the same effect as in Example 3.

[0161] Example 6: As Figure 3As shown, the composite material is a hot-pressed composite material consisting of a perforated PE film, a non-woven fabric, an EPTFE film, and another non-woven fabric layered sequentially. The press lines are all 1.5 mm wide and spaced 3.5 mm apart, with a press area to non-press area ratio of 3:7. The perforated PE film, EPTFE film, and non-woven fabric are all the same size. Disposable absorbent materials are as follows... Figure 9 As shown. The permeable layer has a basis weight of 40 g / m³. 2 Hydrophilic hot air nonwoven fabric, absorbent layer is 400g / m² 2 The composite core has a water-blocking side weight of 22g / m². 2 Water-repellent hot air nonwoven fabric. The composite material is laid flat below the absorbent layer, with a perforated PE membrane on the side closest to the absorbent layer.

[0162] The PE perforated membrane has a basis weight of 18 g / m³. 2 Air permeability 2300mm / s, pore density 300×10 4 / m 2 The porosity is 15%, the maximum equivalent diameter of the through-hole (Demax) is 0.25 mm, the minimum equivalent diameter of the through-hole (Demin) is 0.15 mm, and the moisture permeability is 2700 g / m². 2 / 24h. The larger pore diameter end faces the EPTFE membrane, and the smaller pore diameter end faces the absorber core.

[0163] The EPTFE membrane has a basis weight of 2.0 g / m³. 2 Air permeability 100mm / s, moisture permeability 4000g / m² 2 / 24h.

[0164] All nonwoven fabrics are SSMMS nonwoven fabrics with a basis weight of 5g / m². 2 .

[0165] The only difference between Example 9 and Example 6 is that the EPTFE membrane is on the side closer to the absorber layer.

[0166] The moisture permeability of Examples 6 and 9 was tested, and the results are shown in Table 7.

[0167]

[0168] Table 7

[0169] As shown in Table 7, under the premise of ensuring no leakage in actual application of the finished product, the PE perforated membrane is more suitable to be attached to the side of the absorbent core. When the moisture permeability is basically the same, it can improve the leakage resistance of the finished product.

[0170] As can be seen from the above implementation examples, the introduction of PE perforated membrane can indeed reduce the moisture released into the external environment during the use of disposable hygiene products. However, whether the remaining moisture released by the absorbent layer is trapped in the core can lead to a higher temperature and humidity between the absorbent product and the human skin, creating a stuffy feeling similar to that of the PE membrane. Therefore, in the test of Example 6, the weight changes of the bottom membrane and the absorbent filter paper were weighed to determine the flow of internal moisture. Performance tests were conducted on Examples 6, 9, Comparative Example 7, and Comparative Example 3, and the results are shown in Table 8.

[0171]

[0172] Table 8

[0173] As shown in Table 8, under the premise of no leakage in actual application of the finished product, the total moisture vapor discharged by the PE perforated membrane close to the absorbent core is basically the same as that of the EPTFE composite material. However, the moisture vapor discharged into the external environment is reduced by about 50%. It was also observed that the moisture vapor turns from water vapor into liquid water after cooling and is stored in the interlayer space between the PE perforated membrane and the EPTFE membrane. The liquid water formed by this cooling is eventually absorbed by the upper core through the pores of the PE perforated membrane, reducing the possibility of leakage of the EPTFE membrane and not blocking the air and moisture permeability channels.

[0174] The reverse absorption effect of the composite material in Example 6 was tested (test liquid 300ml), and the results are shown in Table 9.

[0175]

[0176] Table 9

[0177] As shown in Table 9, the PE perforated membrane is close to the absorbent core, and the larger pore diameter faces the EPTFE membrane while the smaller pore diameter faces the absorbent core. This structure allows the liquid water contained in the composite material interlayer space to be drawn back to the upper core, thus not affecting subsequent air permeability and moisture permeability, and providing good comfort and leak-proof performance.

[0178] It should be noted that:

[0179] The porosity is the percentage of the area at one end of the through-hole with a diameter of Demax to the total area of ​​the material.

[0180] The test method and standard for the air permeability of sheet materials shall be conducted in accordance with the provisions of GB / T 5453.

[0181] The test method and standard for the moisture permeability of sheet materials shall be conducted in accordance with the provisions of ASTM E96.

[0182] Finished product moisture permeability (g / 10min): 400ml, 40℃ pure water, calculate the weight change of the absorbent filter paper under the permeable membrane after 10min. (Finished product placed on a stone slab surface).

[0183] Leakage of finished product:

[0184] (1) Leakage rate of diapers according to national standard: Tested in accordance with the provisions of GBT 28004-2021.

[0185] (2) Anti-squeezing leakage: Pour in 400ml of physiological saline at 37℃, hold the diaper on both sides and squeeze it towards the core. After 10 seconds, observe and record the leakage changes of the impermeable bottom layer.

[0186]

[0187] (3) Pressure-resistant leakage: Pour in 400ml of physiological saline at 37℃, apply 10kPa pressure to the surface layer, and observe and record the leakage points and weight changes of the paper towel below the impermeable bottom layer after 1 minute.

[0188]

[0189] The present invention and its embodiments have been described above illustratively. This description is not restrictive, and the figures shown are only one embodiment of the present invention; the actual structure is not limited thereto. Therefore, if those skilled in the art are inspired by this description and design similar structures and embodiments without departing from the inventive spirit of the present invention, such designs should fall within the protection scope of the present invention.

Claims

1. A composite material, characterized in that: It includes a laminated EPTFE membrane (102) and a moisture-proof and gas-proof membrane (101); The moisture-proof and air-proof membrane (101) is provided with through holes (103); with the surface of the EPTFE membrane (102) as the projection surface and the direction perpendicular to the surface of the EPTFE membrane (102) as the projection direction, the projection of the through holes (103) along the projection direction is located on the projection surface; The EPTFE membrane (102) and the moisture-proof and air-proof membrane (101) are bonded and fixed in a certain area; The moisture-proof and air-proof membrane (101) is in direct contact with the EPTFE membrane (102), or a barrier layer is provided between the moisture-proof and air-proof membrane (101) and the EPTFE membrane (102).

2. The composite material according to claim 1, characterized in that: All through holes (103) have approximately the same diameter at both ends; Alternatively, some through holes (103) have approximately equal diameters at both ends, while the diameter at one end of the remaining through holes (103) is larger than the diameter at the other end. Alternatively, the diameter of one end of all through holes (103) is larger than the diameter of the other end.

3. The composite material according to claim 2, characterized in that: The larger end of the through-hole (103) faces the EPTFE membrane (102); Alternatively, the smaller end of the through-hole (103) faces the EPTFE membrane (102); Alternatively, some through holes (103) have their larger diameter ends facing the EPTFE membrane (102), while the smaller diameter ends of the remaining through holes (103) face the EPTFE membrane (102).

4. The composite material according to claim 2, characterized in that: The inner diameter of the larger end of the through hole (103) is denoted as Demax, and the inner diameter of the smaller end of the through hole (103) is denoted as Demin. 1 / 10≤Demin / Demax<1 / 1; the value of Demin ranges from 0.05mm to 1.0mm.

5. The composite material according to claim 1, characterized in that: The moisture-proof and air-proof membrane (101) has an opening ratio of 5% to 40% and an opening density of (1-1000)*10. 4 pcs / m 2 .

6. The composite material according to claim 1, characterized in that: The air permeability of the moisture-proof and air-proof membrane (101) is 100-10000 mm / s, and the moisture permeability is 100-5000 g / m. 2 / 24h.

7. The composite material according to claim 1, characterized in that: The air permeability of the moisture-proof and air-proof membrane (101) is greater than that of the EPTFE membrane (102), and both the air permeability of the moisture-proof and air-proof membrane (101) and the air permeability of the EPTFE membrane (102) are greater than that of the composite material.

8. The composite material according to claim 1, characterized in that: The moisture permeability of the moisture-proof and air-proof membrane (101) is less than that of the EPTFE membrane (102), and both the moisture permeability of the moisture-proof and air-proof membrane (101) and the moisture permeability of the EPTFE membrane (102) are greater than that of the composite material.

9. The composite material according to claim 1, characterized in that: The EPTFE membrane (102) has a first nonwoven fabric (201) disposed on the side opposite to the moisture-proof and air-proof membrane (101); The first nonwoven fabric (201) is bonded and fixed to the EPTFE membrane (102) in a certain area.

10. The composite material according to any one of claims 1-9, characterized in that: The barrier layer is a second nonwoven fabric (202); And / or, a third nonwoven fabric (203) is provided on the side of the moisture-proof and air-proof membrane (101) facing away from the EPTFE membrane (102); The third nonwoven fabric (203) is bonded and fixed to the moisture-proof and air-proof membrane (101) in some areas.

11. An absorbent product, characterized in that: The composite material comprising a liquid-permeable layer (301) and an absorbent layer (303) stacked together, as described in any one of claims 1-10; In the composite material, the moisture-proof and gas-proof membrane (101) is close to the absorber layer (303), or the EPTFE membrane (102) in the composite material is close to the absorber layer (303); The unbonded area between the moisture-proof and air-proof membrane (101) and the EPTFE membrane (102) forms a composite material interlayer space.

12. The absorbent article according to claim 11, characterized in that: The moisture-proof and air-proof membrane (101) is close to the absorption layer (303), and the larger end of the through hole (103) is close to the EPTFE membrane (102), while the smaller end of the through hole (103) is close to the absorption layer (303). The liquid formed by the cooling of the moisture contained in the composite interlayer space is absorbed by the absorption layer (303) through the through hole (103).

13. The absorbent article according to claim 11, characterized in that: The EPTFE membrane (102) in the composite material has a porous structure with a porosity of not less than 70% and a pore size range of 0.1 to 1.5 micrometers.

14. The absorbent article according to claim 11, characterized in that: The absorbent layer (303) is formed by a composite of a superabsorbent polymer material and one or more of wood pulp fiber, nonwoven fabric, fluffy cotton, and dust-free paper.

15. The absorbent article according to claim 11, characterized in that: When the moisture-proof and air-proof membrane (101) of the composite material is located on the side close to the absorbent layer (303), a urine indicator adhesive (304) is provided on the side of the moisture-proof and air-proof membrane (101) close to the absorbent layer (303), and the urine indicator adhesive (304) avoids the through hole (103).

Images