A disposable, high permeability composite fibrous material, method of manufacture, apparatus and sanitary article

Abstract

The present application relates to a kind of disposable high air-permeable composite fiber material, manufacturing method, device and sanitary product, belong to non-woven fabric manufacturing technical field.High air-permeable composite material includes EPTFE film and first non-woven fabric stacked in sequence, and EPTFE film and non-woven fabric are fixed by bonding portion with adhesion, and the projection area of bonding portion on impermeable bottom layer is 3:1-1:20 compared with the non-bonding area outside bonding portion.The design of non-crossing, non-forking, uninterrupted, smooth, continuous linear bonding portion pattern can effectively avoid stress concentration or cause EPTFE film damage at crossing, forking, discontinuous and non-smooth bonding portion, thereby causing leakage.The bonding area and non-bonding area ratio can ensure the bonding effect while trying to ensure the original micropore, air-permeable effect and softness of EPTFE film.

Description

Technical Field

[0001] This invention relates to a disposable high-breathability composite fiber material, its manufacturing method, apparatus, and sanitary products, belonging to the field of nonwoven fabric manufacturing technology. Background Technology

[0002] With social development and improved living standards, the popularity of disposable hygiene products is increasing. While demanding good absorbency and dryness, people are also placing higher demands on breathability and softness / comfort. If disposable hygiene products lack breathability, after urine, loose stools, menstrual blood, or breast milk are absorbed, a large amount of hot and humid vapor accumulates inside, unable to be expelled or cooled in time, leading to a stuffy feeling and, in severe cases, even redness and inflammation. Currently, most disposable hygiene products on the market use PE or PP film as the primary waterproof and breathable material. Although PE or PP film has excellent waterproof properties, its breathability is far from ideal, failing to meet consumer needs.

[0003] Conventional PE breathable membranes with added calcium carbonate consist of tiny calcium carbonate particles added to the PE membrane. Utilizing the ductility of PE and the non-ductility of calcium carbonate particles, a stretching process during PE membrane manufacturing creates tiny gaps around the calcium carbonate particles. Some of these tiny gaps are interconnected, resulting in slight air permeability. However, due to the non-ductility of calcium carbonate, adding too much calcium carbonate will cause the membrane to become brittle and its tensile strength to be greatly reduced, thus making it unsuitable for use in absorbent products.

[0004] Patent CN216148354U discloses a method using a highly breathable and ultra-soft EPTFE membrane or a composite material of it and non-woven fabric to replace the impermeable liquid-proof bottom layer containing PE or PP membranes in traditional disposable hygiene products. The EPTFE membrane has uniformly distributed micropores with a diameter of 0.1μm to 0.5μm. Utilizing the diameter difference between a minimum water droplet diameter of 10μm and a water vapor molecule diameter of 0.4nm, it achieves the effect of impermeability for water droplets while allowing water vapor molecules to pass through. However, to achieve high breathability and reduce costs, the EPTFE membrane usually needs to be made very thin and with a very low basis weight. When the basis weight of EPTFE membrane is reduced to approximately 2 g / m², the membrane thickness is approximately 0.002 mm. Using such a lightweight membrane alone for absorbent hygiene products becomes difficult due to its softness, thinness, and extreme susceptibility to shrinkage and deformation. This shrinkage and deformation also significantly reduces the breathability of the EPTFE membrane. Experiments have shown that when the width of the EPTFE membrane shrinks by 10% due to stretching deformation, the breathability decreases by approximately 20-30%. Production speeds also need to be very low, which cannot meet the requirements of disposable hygiene product production lines exceeding 200 m / min. Furthermore, proper treatment of the EPTFE membrane before use in absorbent products, especially when laminated with high-breathability, high-tensile-strength, low-cost nonwoven fabrics, is essential. To ensure good water resistance of the composite material, water-repellent nonwoven fabrics are selected. However, the layers of materials in hygiene products are typically bonded together using hot melt adhesives, which are difficult to adhere to the surface of the EPTFE membrane. Therefore, current technologies generally use light roller thermal lamination or adhesive lamination, both of which have serious drawbacks. Thermal lamination using optical rollers typically involves bonding an EPTFE film onto the high-temperature metal optical roller and a rubber roller. During lamination, the EPTFE film is adhered to the high-temperature metal optical roller, while the nonwoven fabric is simultaneously bonded to the rubber roller. The heat from the high-temperature metal optical roller penetrates the EPTFE film and reaches the surface of the nonwoven fabric, causing it to melt. Some of the molten nonwoven fabric enters the micropores of the EPTFE, forming a nail-like structure. This structure re-solidifies and bonds as the temperature decreases after the EPTFE and nonwoven fabric leave the high-temperature bonding area between the two rollers. The main drawbacks of this lamination method are low composite strength and high energy consumption. Typically, the temperature of the metal optical roller adhering to the EPTFE film needs to be around 350°C to achieve bonding, because the fibers that make up the nonwoven fabric are usually PE or PP surface layers, whose melting point is only 110-170°C. This results in a brittle composite material that is prone to crumbling. Most importantly, it significantly reduces air permeability, typically by 50-80% compared to the original EPTFE film.Adhesive bonding is usually achieved by spraying hot melt adhesive across the entire surface between the EPTFE membrane and the nonwoven fabric. However, because the surface of the EPTFE membrane is difficult to bond, the composite film produced by adhesive bonding usually does not achieve sufficient adhesive strength. The adhesive strength between the layers of sanitary materials needs to be no less than 1 kgf, but adhesive bonding usually cannot achieve this adhesive strength. The adhesive force between the layers of adhesive bonding is usually less than 0.5 kgf, which makes sanitary products prone to delamination, thus affecting consumer use. Even when combining the two methods mentioned above to improve the adhesion between EPTFE and nonwoven fabric, the pressure during this processing method causes more adhesive to penetrate through the nonwoven fabric and EPTFE membrane, sticking to the roller surface and affecting the adhesion quality and damaging the EPTFE membrane surface, thus affecting its water resistance. In addition, hot melt adhesive can also cause some adhesive to penetrate through the nonwoven fabric and EPTFE membrane to reach their other side. This adhesive will come into contact with the other side of the EPTFE membrane during winding. Since the EPTFE membrane is very thin, there is a risk of membrane tearing when the composite membrane is unwound after winding and used to produce sanitary products, thus affecting the waterproof performance of the composite membrane. Adhesive that enters or passes through the micropores of the EPTFE membrane will seriously affect the air permeability of the EPTFE membrane. After multiple verifications and calculations, even an adhesive amount as low as 0.5 g / m² will reduce the air permeability of the composite breathable membrane by 40%-50%.

[0005] EPTFE film is an expanded polytetrafluoroethylene (PTFE) film formed by bidirectional (longitudinal and transverse) stretching of polytetrafluoroethylene. When using a liquid-impermeable bottom layer made of EPTFE and non-woven fabric as the bottom layer of a sanitary napkin, if the side of the EPTFE film faces the core and the top layer, the perimeter seal formed by the bonding of the top layer and the EPTFE film around the core is usually relatively weak due to the poor adhesion of the EPTFE film surface. This can easily lead to the seal breaking during consumer use, affecting usability. If the side of the EPTFE film faces the adhesive side, the adhesion between the adhesive and the EPTFE film is also usually very low (usually less than 70 g / f), while the adhesive strength of sanitary napkins (the adhesion between the adhesive and underwear) is usually around 100 g / f. This can cause the adhesive to transfer to the surface of underwear during consumer use, posing a risk. Existing technology can be found in CN216148354U.

[0006] Urine indicator gel is an absorbent hygiene product designed to help consumers observe whether a user has urinated. It changes color upon contact with urine or water, typically from yellow to blue or from white to blue. Some urine indicator gels contain highly polar hydrophilic components and indicators, making their hydrophilicity and permeability stronger than that of urine and water. If the urine indicator gel is applied directly to a highly breathable EPTFE membrane, the strong hydrophilic components in the gel can penetrate into or pass through the micropores of the EPTFE membrane. This can cause leakage when the user urinates heavily, as some of the water in the urine can seep through the micropores of the EPTFE membrane, causing inconvenience to the consumer – something neither consumers nor users want. Summary of the Invention

[0007] The first technical problem to be solved by this invention is that when EPTFE is laminated with nonwoven fabric, the existing high-temperature light roller thermal lamination or adhesive lamination methods can easily lead to the composite material being hard, brittle, and prone to flaking, as well as poor air permeability of the composite layer and unstable quality of the air permeable membrane layer. Regarding this technical problem, the technical concept adopted in this invention is as follows: To ensure that the bonding strength between the EPTFE film and the nonwoven fabric exceeds 1 kgf, and to ensure that the EPTFE film will not be damaged, affecting its waterproofness, and to further ensure the high air permeability of the EPTFE film, this patent creatively employs a combination of striped raised steel rollers and smooth-surfaced steel rollers to achieve bonding between the EPTFE film and the nonwoven fabric. Both the striped raised steel rollers and the smooth-surfaced steel rollers have heating functions, and the pressure between the two rollers is achieved by a hydraulic system with adjustable pressure. The area ratio of the raised stripe surface area to the non-raised steel roller surface area is 3:1-1:20. This composite method has the following advantages: 1. To avoid the problem of composite material brittleness caused by traditional high-temperature heat-sealing rollers to rubber rollers, this design uses a combination of hydraulic and thermal bonding to achieve bonding. The bonding temperature only needs to be around 100 degrees Celsius, far lower than the high temperature of over 350 degrees Celsius required for traditional bonding, which can save energy and prevent the material from becoming brittle due to high temperatures. 2. To avoid the decrease in air permeability caused by gluing and traditional heat sealing with smooth rollers, this patent adopts a partial bonding design. With a pressed area to unpressed area ratio of 1:3, the interlayer adhesion between EPTFE and nonwoven fabric can reach 5-10 kgf, and the air permeability of the composite high-permeability material will only decrease by about 20 mm / s compared to the air permeability of a single-layer EPTFE membrane. Since the air permeability of the pressed portion is lower than that of the unpressed portion, the proportion of the pressed portion to the total area should not be too high. 3. High pressure and heating work together to form sufficient interlayer adhesion; with a pressed area to unpressed area ratio of 1:3, the interlayer adhesion between EPTFE and nonwoven fabric can reach 5-10 kgf. 4. The design of a smooth, continuous linear adhesive pattern without intersections, bifurcations, or breaks effectively avoids stress concentration or EPTFE membrane damage and leakage at intersections, bifurcations, breaks, and uneven adhesive areas. 5. This structure can also achieve multi-layer material composites without increasing the number of glue machines or rollers, meeting various needs. Furthermore, if the adhesive section curve has intersections, bends, or excessive curvature at any point, it can cause EPTFE membrane leakage under pressure. Therefore, this patent employs an adhesive section with a smooth curved projection shape, ensuring that it will not be subjected to excessive pressure at any point, thus preventing rupture and leakage. This projection shape can be a straight line, a smooth curve, a non-smooth line, a circle, or an ellipse.When it is a straight line, there are no bending areas overall; when it is a curve, there will be some bends on the curve, and it is necessary to ensure that the curvature of any bend on the curve is less than 400m. -1 (That is, the radius of curvature is greater than 0.0025m). When it is a broken line, there will be a certain angle between adjacent line segments, and any angle must be greater than 120°. When it is a circle, the radius must be greater than 0.0025m. When it is an ellipse, the curvature at any position on the arc of the ellipse must be less than 400m. -1 (That is, the radius of curvature is greater than 0.0025m). Alternatively, a non-closed ring can be used, as long as the curvature at any point within the ring is less than 400m. -1 (i.e., a radius of curvature greater than 0.0025m) ensures that there are no excessively small angles between line segments, preventing stress concentration. The aforementioned curve can be either continuous or discontinuous. 6. Avoiding the problems of conventional high-temperature roller-to-roller hot-pressing composite materials being hard, brittle, and prone to flaking, having poor air permeability of the composite layer, unstable quality of the breathable membrane layer, and severe degradation of the air permeability of adhesive materials: High-temperature roller-to-roller hot-pressing composite generally uses EPTFE and non-woven fabric. The high-temperature roller contacts the EPTFE membrane, and the non-woven fabric contacts the other roller. The temperature of the high-temperature roller is generally around 350 degrees Celsius. The high temperature transfers heat from one side of the EPTFE membrane to the other side of the non-woven fabric, causing the non-woven fabric to melt. This melted non-woven fabric enters the pores of the EPTFE membrane, forming a nail-like inlay structure to achieve adhesion with the EPTFE. This adhesion will block a large portion of the EPTFE membrane pores, making the composite material very hard and brittle, and also causing the EPTF... The air permeability of E-film decreases significantly. Typically, the air permeability of the composite material is more than 50%-80% lower than that of the original EPTFE film. As mentioned earlier, when using adhesive bonding, the low bonding strength between layers also reduces the air permeability by 40-50%. The solution of this invention uses a composite material with a bonding area to non-bonded area ratio of 3:1 to 1:20, which can achieve good bonding strength at low temperatures. Its local bonding design can avoid and reduce caking and a significant decrease in air permeability. It has been verified that the composite breathable material of this invention can control the decrease in air permeability to within 20%, which means that the air permeability of the composite breathable material can be basically guaranteed to be about 80% of that of the EPTFE film. Its air permeability is far better than conventional high-temperature roller-to-roller hot pressing and bonding. 7. The bonding method of the present invention can improve the hydrostatic pressure resistance (water resistance) of the composite material. Studies have verified that, compared with the three-layer composite material that is not bonded together, the high-permeability composite material of the present invention can improve the hydrostatic pressure resistance by about 30-50%. The higher the hydrostatic pressure resistance, the higher the water resistance performance and the better the water resistance.

[0008] The second technical problem this invention aims to solve is that when using a liquid-impermeable bottom layer made of a double-layer composite material of EPTFE and non-woven fabric as the bottom layer of a sanitary napkin, if one side of the EPTFE film faces the core and the top layer, the strength of the perimeter seal formed by the bonding of the top layer and the EPTFE film around the core is usually relatively low due to the poor adhesion of the EPTFE film surface. Since the liquid-impermeable bottom layer of a sanitary napkin needs good adhesion on both sides, this invention creatively adopts a non-woven fabric / EPTFE / non-woven fabric structure. In this three-layer material structure, the EPTFE film is sandwiched in the middle, ensuring that both sides of the film have non-woven fabric facing outwards. One side of the non-woven fabric can effectively bond the core and the top layer, while the other side can effectively bond the adhesive backing and release paper. This provides good fixation when the consumer removes the release paper and attaches the sanitary napkin to their underwear, ensuring it does not shift or fall off. Similarly, because this invention has a three-layer sandwich structure, when used in the liquid-proof bottom layer of products such as pull-up pants and diapers, adhesives can be used to bond the first layer of non-woven fabric well to the core, the diversion layer, the covering layer, the surface layer, or the leak-proof side panels. Adhesives can also be used to firmly bond the third layer of non-woven fabric to the outermost non-woven fabric of the diaper or pull-up pants, thereby avoiding problems such as delamination that affect consumer use. This fully leverages the high breathability advantage of this invention, which is conducive to the removal and cooling of hot and humid air, improving the user experience and consumer satisfaction.

[0009] The third technical problem this invention aims to solve is that existing methods for laminating EPTFE with nonwoven fabrics typically employ light roller thermal lamination or adhesive lamination. However, these methods suffer from low composite strength and reduced air permeability. This patent addresses this issue by using heat-pressing or ultrasonic bonding between EPTFE and nonwoven fabric, achieving sufficient adhesive strength between them. Simultaneously, the nonwoven side of the composite material is fully capable of bonding other materials with hot melt adhesives. Furthermore, the EPTFE side exhibits improved hot melt adhesiveness due to the altered surface energy at the bonding point. This high-permeability composite material, employing a nonwoven / EPTFE nonwoven structure, uses nonwoven fabric on both sides for contact bonding with other materials. The bonding strength, especially the adhesive strength, fully meets usage requirements, satisfying the needs of consumers and users.

[0010] The fourth technical problem this invention aims to solve is that when using an EPTFE membrane as a liquid-impermeable layer, if a color-developing adhesive needs to be laminated into the diaper, the adhesive can easily permeate into the EPTFE. To solve this problem while maintaining the high breathability of the material, a composite high-breathability material consisting of an EPTFE membrane and nonwoven fabric can be selected, with the nonwoven side facing the core. A layer of water-repellent nonwoven fabric, particularly a water-repellent spunbond meltblown nonwoven fabric similar to SMMS containing an M (meltblown) layer, is added between the liquid-impermeable bottom layer formed by EPTFE and the core. Since the adhesive content of the urine indicator is very low, and the hydrophilicity of the adhesive is stronger than that of urine and water, adding a layer of water-repellent nonwoven fabric and applying the urine indicator adhesive to the side of this material facing the core can effectively prevent or reduce urine leakage, meeting national standards and user requirements. It also has virtually no impact on overall breathability. Some urine indicator adhesives contain color-developing indicators and highly hydrophilic components to accelerate color change. Their hydrophilicity and permeability are far stronger than those of urine and water. These types of urine indicator adhesives may affect the water resistance of the high-permeability composite material in the area where the adhesive is applied. To ensure that the type of urine indicator adhesive desired by customers can be used in diaper products with leak-proof properties, this invention creatively adds a second water-resistant layer with a water resistance higher than that of the high-permeability EPTFE membrane. Its width and length are just enough to ensure the application of the urine indicator adhesive. Because its area is very small (typically, the width of a high-permeability composite membrane is around 170mm, while the urine indicator adhesive application is generally 2-4mm, and the length is about half that of the high-permeability composite membrane), the permeability of the second water-resistant layer material, whether higher or lower than that of the EPTFE membrane, will not significantly affect the permeability of the composite high-permeability material made from the EPTFE membrane, effectively solving the risk of urine indicator adhesive leakage.

[0011] A highly permeable composite material includes an EPTFE membrane and a first nonwoven fabric stacked sequentially, wherein the EPTFE membrane and the nonwoven fabric are bonded and fixed together by an adhesive portion, and the ratio of the projected area of ​​the adhesive portion on the first liquid-impermeable bottom layer to the non-adhesive area outside the adhesive portion is 3:1-1:20 (or 2.5:1-1:1, 2:1-1:15, 1.5:1-1:12, or 1:1-1:5).

[0012] The aforementioned highly breathable composite material is used in hygiene products, and is made of... Figure 1 Therefore, when used in sanitary products, it can be referred to as the first impermeable liquid bottom layer.

[0013] The air permeability of the adhesive portion is lower than that of the non-adhesive portion;

[0014] The thickness of the adhesive portion is lower than the thickness of the non-adhesive portion; the thickness of the first nonwoven fabric is higher than that of the EPTFE film; the size, position, and shape of the projected area of ​​the plurality of adhesive portions on the first nonwoven fabric are consistent with the size, position, and shape of the projected area of ​​the plurality of adhesive portions on the EPTFE film.

[0015] The adhesive portions are distributed on the first impermeable substrate, and there are no connections between adjacent adhesive portions.

[0016] The projection shape of the adhesive portion on the first impermeable substrate is any one of the following: curved, broken, straight, annular, circular, elliptical, or a combination thereof.

[0017] When the projected shape is curved, the curvature at any bend in the curve must be less than 400m. -1 When the projected shape is a broken line, the included angle between any two adjacent line segments must be greater than 120°; when the projected shape is a circle, the radius must be greater than 0.0025m; when the projected shape is an ellipse, the curvature of any point on the arc of the ellipse must be less than 400m. -1 When the projected shape is annular (non-closed ring), any point within the ring satisfies a curvature less than 400m. -1 (The curvature mentioned above can also be selected from less than 300 m.) -1 250 m -1 200 m -1 150 m -1 100 m -1 80 m -1 50 m -1 20m -1 10 m -1 5 m -1 (The included angles can also be greater than 130°, 140°, 150°, 160°, or 170°.)

[0018] The projected shape of the adhesive portion on the first impermeable substrate is continuous, and there is no connection between adjacent adhesive portions.

[0019] The line width of the adhesive part is 0.1mm-10mm.

[0020] The distance between the lines of adjacent adhesive parts is 0.1mm-200mm.

[0021] The EPTFE membrane faces the absorbent core; or, the first nonwoven fabric faces the absorbent core.

[0022] The first liquid-impermeable bottom layer also includes a second nonwoven fabric, located on the side of the EPTFE membrane opposite to the first nonwoven fabric, or on the side of the first nonwoven fabric opposite to the EPTFE membrane.

[0023] A highly breathable composite material includes a second nonwoven fabric, an EPTFE membrane, and a first nonwoven fabric stacked sequentially. The EPTFE membrane and the nonwoven fabric are bonded and fixed together by an adhesive portion. The ratio of the projected area of ​​the adhesive portion on the first liquid-impermeable substrate to the non-adhesive area outside the adhesive portion is 3:1-1:20 (or 2.5:1-1:1, 2:1-1:15, 1.5:1-1:12, or 1:1-1:5). When using the second nonwoven fabric, the area ratio and shape of the adhesive points are not limited as described above, as long as the EPTFE and the first nonwoven fabric can be composited through a certain adhesive portion; the area ratio and shape characteristics of the adhesive portion described above are preferred.

[0024] The second nonwoven fabric is fixed to the EPTFE membrane via an adhesive part, which is exactly the same as the adhesive part between the first nonwoven fabric and the EPTFE membrane.

[0025] The air permeability of the adhesive portion is lower than that of the non-adhesive portion;

[0026] The thickness of the adhesive portion is lower than the thickness of the non-adhesive portion;

[0027] The thickness of the first nonwoven fabric and / or the second nonwoven fabric is greater than that of the EPTFE film;

[0028] The size, position, and shape of the projected area of ​​the plurality of adhesive portions on the first nonwoven fabric are consistent with the size, position, and shape of the projected area of ​​the plurality of adhesive portions on the EPTFE film.

[0029] The size, position, and shape of the projected area of ​​the plurality of adhesive portions on the second nonwoven fabric are consistent with the size, position, and shape of the projected area of ​​the plurality of adhesive portions on the EPTFE film.

[0030] The adhesive portions are distributed on the first impermeable substrate, and there are no connections between adjacent adhesive portions.

[0031] The projection shape of the adhesive portion on the first impermeable substrate is any one of the following: curved, broken, straight, annular, circular, elliptical, or a combination thereof.

[0032] When the projected shape is curved, the curvature at any bend in the curve must be less than 400m. -1When the projected shape is a broken line, the included angle between any two adjacent line segments must be greater than 120°; when the projected shape is a circle, the radius must be greater than 0.0025m; when the projected shape is an ellipse, the curvature of any point on the arc of the ellipse must be less than 400m. -1 When the projected shape is annular (non-closed ring), any point within the ring satisfies a curvature less than 400m. -1 (The curvature mentioned above can also be selected from less than 300 m.) -1 250 m -1 200 m -1 150 m -1 100 m -1 80 m -1 50 m -1 20m -1 10 m -1 5 m -1 (The included angles can also be greater than 130°, 140°, 150°, 160°, or 170°.)

[0033] The air permeability of the adhesive portion is lower than that of the non-adhesive portion;

[0034] The projected shape of the adhesive portion on the first impermeable substrate is continuous, and there is no connection between adjacent adhesive portions.

[0035] The line width of the adhesive part is 0.1mm-10mm.

[0036] The distance between the lines of adjacent adhesive parts is 0.1mm-200mm.

[0037] The second nonwoven fabric faces the absorbent core; or, the first nonwoven fabric faces the absorbent core.

[0038] The air permeability of the first nonwoven fabric is greater than or equal to that of the second nonwoven fabric, and both of their air permeability are greater than that of the EPTFE membrane.

[0039] The air permeability of the first nonwoven fabric, the second nonwoven fabric, and the EPTFE membrane is higher than that of the first liquid-impermeable bottom layer.

[0040] The first and / or second nonwoven fabrics are water-repellent nonwoven fabrics.

[0041] The water-repellent nonwoven fabric is one of the following: hot air nonwoven fabric, hot-rolled nonwoven fabric, spunlace nonwoven fabric, SS spunbond nonwoven fabric, SMS nonwoven fabric, SMMS nonwoven fabric, or nonwoven fabric composed of multiple layers of S and multiple layers of M, or a composite nonwoven fabric thereof.

[0042] The EPTFE membrane has a thickness of 0.0001mm to 1mm and an air permeability of 1-600mm / s.

[0043] A disposable high-permeability composite fiber material includes a liquid-permeable top layer, an absorbent core, and a first liquid-impermeable bottom layer stacked sequentially, wherein the first liquid-impermeable bottom layer contains an EPTFE membrane.

[0044] The first impermeable substrate contains the aforementioned highly permeable composite material.

[0045] The disposable high-permeability composite fiber material further includes a urine indicator gel between the first impermeable bottom layer and the absorbent core.

[0046] A disposable, highly breathable composite fiber material includes a liquid-permeable top layer, an absorbent core, and a first liquid-impermeable bottom layer, stacked sequentially. It also includes a second liquid-impermeable bottom layer located between the first liquid-impermeable bottom layer and the absorbent core, with a urine indicator adhesive coated on the second liquid-impermeable bottom layer facing the absorbent core. (When using the second liquid-impermeable layer, the area ratio and shape of the adhesive points in the first liquid-impermeable layer are not limited as described above, as long as EPTFE and the first nonwoven fabric can be bonded together through a certain adhesive portion; preferably, the area ratio and shape characteristics of the adhesive portion described above are used; the second liquid-impermeable bottom layer and EPTFE can be fixed by thermal bonding or ultrasonic bonding).

[0047] The second impermeable bottom layer can be PE film, PE breathable film, PP, PVA, PA, EVOH, PVDC, EVA, CPP, spunbond nonwoven fabric, spunlace nonwoven fabric, hot air nonwoven fabric, other types of nonwoven fabric or OPP and their composite materials, and may also include EPTFE film or the above-mentioned high breathability composite materials.

[0048] The first impermeable liquid bottom layer includes an EPTFE membrane and / or the aforementioned highly permeable composite material, etc.

[0049] The second impermeable bottom layer has higher water resistance than the first impermeable bottom layer.

[0050] The projected area of ​​the second impermeable bottom layer on the absorbent core is smaller than the projected area of ​​the first impermeable bottom layer on the absorbent core.

[0051] The second liquid-impermeable bottom layer has the properties of repelling blood and urine.

[0052] In addition, the first and / or second nonwoven fabrics in this invention may be treated with a water-repellent finishing agent to improve their water resistance. The water-repellent finishing agent may be paraffin-based, pyridine quaternary ammonium salt, organosilicon, or fluorinated organic compounds, preferably fluorinated organic compounds.

[0053] The urine indicator adhesive in this invention can also be a humidity indicator composite material, which is a water-based adhesive or a hot melt adhesive, and has a first color when dry and a second color when wet, the second color being different from the first color.

[0054] It also includes a leak-proof partition, which contains the aforementioned highly breathable composite material.

[0055] The liquid-permeable top layer is a nonwoven fabric made of one or more of the following: hot-air nonwoven fabric, thermally rolled nonwoven fabric, spunlace nonwoven fabric, spunbond nonwoven fabric, or a combination thereof.

[0056] The absorbent core contains a water-absorbing polymer material.

[0057] The absorbent core is made of a composite of absorbent polymers, wood pulp fibers, non-woven fabrics, fluffy cotton, or dust-free paper.

[0058] A sanitary product comprising the aforementioned highly breathable composite material.

[0059] A sanitary product comprising the above-mentioned disposable highly breathable composite fiber material.

[0060] The hygiene products mentioned include baby diapers, baby pants-style diapers, adult diapers, adult pants-style diapers, incontinence pads, nursing pads, sanitary napkins, menstrual pants, panty liners, maternity pads, or breast pads, etc.

[0061] A method for manufacturing a double-layer high-permeability composite material includes the following steps:

[0062] The EPTFE film and the first nonwoven fabric are pressed together by a patterned roller and a smooth roller, and then shaped and bonded by hot pressing, ultrasonic pressing, or a combination thereof. The shaping and bonding can be done simultaneously with the pressing or in stages. Both the patterned roller and the smooth roller are equipped with temperature-adjustable heating devices.

[0063] It also includes steps for adjusting the pressure, temperature, speed, and gap between the patterned roller and the smooth roller.

[0064] Before the shaping and bonding process, the EPTFE film and the first nonwoven fabric are electrostatically laminated. This electrostatic lamination step uses static electricity to smoothly overlap and bond the EPTFE film and the nonwoven fabric together. This reduces or eliminates EPTFE film narrowing and wrinkles. Reducing narrowing increases the yield of the finished product and also helps reduce air permeability loss. Reducing or eliminating wrinkles ensures the aesthetics, softness, and breathability of the highly breathable composite material.

[0065] During lamination, the EPTFE surface faces the patterned roller, and the nonwoven fabric surface faces the smooth roller; this ensures that the pattern shape and position area of ​​the two layers are consistent, and the raised height of the EPTFE material's pattern is higher than that of the nonwoven fabric, allowing for greater breathability.

[0066] A method for manufacturing a three-layer (non-woven fabric / EPTFE / non-woven fabric) highly breathable composite material includes the following steps: pressing a second non-woven fabric, an EPTFE film, and a first non-woven fabric together with a smooth roller using a first patterned roller, and then fixing them by hot pressing, ultrasonic pressing, or a combination thereof; the first and second patterned rollers include patterned protrusions protruding from the roller surfaces for forming the adhesive portion. The fixing and bonding can be performed simultaneously with the pressing or in stages; both the patterned roller and the smooth roller are equipped with temperature-adjustable heating devices.

[0067] It also includes steps for adjusting the pressure, temperature, speed and gap between the patterned roller and the smooth roller; before the shaping and bonding are fixed, it also includes a step of electrostatically laminating the EPTFE film and the first nonwoven fabric and / or the second nonwoven fabric.

[0068] The pressing of patterned rollers and smooth rollers mentioned in the manufacturing method can also be achieved by pressing patterned rollers together. The patterns of the two pressed patterned rollers can be the same, mirror images, or different.

[0069] The pattern on the patterned roller matches the shape of the adhesive part.

[0070] A processing apparatus for highly permeable composite materials, comprising:

[0071] First patterned roller;

[0072] And a matching roller, wherein the matching roller is a second patterned roller or a smooth roller;

[0073] The first patterned roller and the matching roller work together to bond and laminate the EPTFE film and the first nonwoven fabric, and can also be used to bond and laminate the second nonwoven fabric, the EPTFE film and the first nonwoven fabric to form a disposable high-permeability composite material with an adhesive part.

[0074] The area ratio of the patterned raised areas to the non-patterned raised areas on the first and second patterned rollers is 3:1 to 1:20.

[0075] The planar projection shape of the raised pattern can be any one of the following: curved, broken, straight, ring, circle, ellipse, or a combination thereof.

[0076] When the projected shape is curved, the curvature at any bend in the curve must be less than 400m. -1 When the projected shape is a broken line, the included angle between any two adjacent line segments must be greater than 120°; when the projected shape is a circle, the radius must be greater than 0.0025m; when the projected shape is an ellipse, the curvature of any point on the arc of the ellipse must be less than 400m. -1When the projected shape is annular, any point within the annulus satisfies a curvature less than 400m. -1 .

[0077] The planar projection shape is continuous; there is no connection between adjacent patterned protrusions.

[0078] The width of the raised lines of the pattern is 0.1mm-10mm; the distance between adjacent raised lines of the pattern is 0.1mm-200mm.

[0079] The highly permeable composite material:

[0080] a) The greater the temperature difference between the two sides of a material, the higher its thermal conductivity; the smaller the temperature difference between the two sides of a material, the lower its thermal conductivity.

[0081] b) The greater the pressure difference between the two sides of the material, the higher its air permeability; the smaller the pressure difference between the two sides of the material, the lower its air permeability.

[0082] c) The greater the temperature difference between the two sides of the material, the higher its moisture permeability; the smaller the temperature difference between the two sides of the material, the lower its moisture permeability.

[0083] d) The greater the humidity difference between the two sides of the material, the higher its moisture permeability; the smaller the temperature difference between the two sides of the material, the lower its moisture permeability.

[0084] e) Its thermal conductivity is higher than that of conventional calcium carbonate breathable membranes.

[0085] The hygiene products mentioned:

[0086] f) The greater the temperature difference between the surface layer and the back layer, the higher its thermal conductivity; the smaller the temperature difference between the surface layer and the back layer, the lower its thermal conductivity.

[0087] g) The greater the pressure difference between the surface layer and the back layer, the higher the air permeability; the smaller the pressure difference between the surface layer and the back layer, the lower the air permeability.

[0088] h) The greater the temperature difference between the surface layer and the back layer, the higher the moisture permeability; the smaller the temperature difference between the surface layer and the back layer, the lower the moisture permeability.

[0089] i) The greater the humidity difference between the surface layer and the back layer, the higher the moisture permeability; the smaller the humidity difference between the surface layer and the back layer, the lower the moisture permeability.

[0090] j) Its thermal conductivity is higher than that of sanitary products that use conventional calcium carbonate breathable membrane as an impermeable liquid bottom layer.

[0091] Beneficial effects

[0092] The non-intersecting, non-branching, uninterrupted, smooth, continuous linear adhesive pattern design effectively avoids stress concentration or EPTFE membrane damage and leakage at intersections, bifurcations, discontinuities, and uneven adhesive areas. The ratio of adhesive to non-adhesive area is 3:1 to 1:20, ensuring both adhesion and the original micropores and breathability of the EPTFE membrane.

[0093] During thermal lamination, sufficient layer adhesion is formed through the combination of high pressure and heating. When the ratio of pressed area to unpressed area is 1:3, the layer adhesion between EPTFE and nonwoven fabric can reach 5-10 kgf.

[0094] The structure of non-woven fabric / EPTFE / non-woven fabric can completely solve the problem of EPTFE membrane being difficult to bond. The surface of non-woven fabric has very good thermal bonding or adhesive bonding properties, ensuring that the composite breathable material can bond well with the core or bottom non-woven fabric.

[0095] By adding a second impermeable layer or water-repellent nonwoven layer between the composite membrane of EPTFE and water-repellent nonwoven fabric and the core, the application problem of urine indicator gel is creatively solved.

[0096] The innovative three-layer design—non-woven fabric / EPTFE / non-woven fabric—solves the problem of ensuring that the bottom layer of a sanitary napkin is both highly adhesive to the core and top layer, preventing the napkin from delaminating or opening, and that the adhesive on the other side of the bottom layer has sufficient strength to hold the napkin firmly in place on underwear. This design is also suitable for other absorbent products with adhesive backing, such as nursing pads, mattress protectors, and nursing pads.

[0097] Compared with Example 4 of CN216148354U, the patent of this invention has more novelty and inventiveness. 1) Regarding the problem of EPTFE film not being easy to bond in the double-layer composite material of non-woven fabric / EPTFE structure: the innovative non-woven fabric / EPTFE / non-woven fabric structure with local hot pressing or ultrasonic pressing is adopted to ensure that adhesive and other materials can be bonded on either side, ensuring that the integrity and functionality of the final hygiene product meet consumer needs. For example, for diaper products, it can ensure the bonding with the core. For sanitary napkins, the non-woven fabric / EPTFE / non-woven fabric structure can ensure that the bonding strength between the non-woven fabric on one side and the core meets the requirements, and the non-woven fabric on the other side can ensure that the adhesive on the non-woven fabric does not transfer or shift, thus ensuring the consumer's use. 2) In practical applications, double-layer composite high-permeability materials with nonwoven fabric / EPTFE structure encounter the problem of EPTFE membrane brittleness: In practical applications, because EPTFE needs to be bonded to other materials, or needs to be printed, or needs to be stretched, squeezed, and flipped during the process, double-layer high-permeability composite materials sometimes encounter the problem of EPTFE membrane surface being easily damaged. Damage will lead to its loss of water resistance, which must be avoided. Studies have found that as the basis weight of EPTFE membrane decreases, its tear resistance also decreases. For example, a 6-gram EPTFE membrane is more tear-resistant than a 2-gram EPTFE membrane. That is, the surface of a 6-gram EPTFE membrane is less likely to be damaged when subjected to friction, squeezing, rubbing, pulling, separation after gluing, heat sealing, or separation after ultrasonic composite. However, a 2-gram EPTFE membrane has a better cost advantage and higher breathability for the final absorbent hygiene products. Therefore, innovation is needed to improve and solve these contradictions. The three-layer composite high-breathability material, made using the nonwoven fabric / EPTFE / nonwoven fabric structure and pattern partial bonding process of the present invention, has nonwoven fabric material on both sides. This can improve breathability while reducing the weight and cost of the EPTFE film (e.g., reducing the 6-gram EPTFE film to a 2-gram EPTFE film). It can also ensure that the EPTFE film surface is not damaged when other materials need to be bonded, or when printing or stretching, squeezing and flipping are required in the process. This ensures that the water resistance and the final absorbent hygiene product functions of the composite high-breathability material are perfectly presented.3) In the embodiment described in CN216148354U, 10-15 g / mS is preferably used, the EPTFE film thickness is preferably 10-15 μm, the weight of the hot-air nonwoven fabric is preferably 18-20 g / m, the air permeability of the composite material is 16 mm / m², and the total weight of the high-permeability composite material is 30-40 g / m². This invention employs an innovative nonwoven fabric / EPTFE / nonwoven fabric structure using localized hot pressing or ultrasonic bonding, with the first layer of nonwoven fabric preferably having a weight of 7 g / m². The SSMMS, wherein the EPTFE membrane is preferably 1-3 μm thick, the second nonwoven fabric is preferably 7 g / m² SSMMS, the total weight of the composite high-permeability material is 15-16 g, and the air permeability of the high-permeability composite material can reach about 80-160 mm / s. Compared with CN216148354U, the weight of the new technology and new material of this invention is reduced by 50%-60%, that is, the cost is reduced by 50%-60%, and the air permeability is increased by about 5-10 times, which has obvious advantages.

[0098] The processing method of the nonwoven fabric / ETFE / nonwoven fabric of the present invention not only maintains the air permeability of the composite material (avoiding the large-scale loss of air permeability caused by adhesive bonding and 100% area heat bonding), but also ensures the bonding strength between the upper and lower nonwoven fabrics and the EPTFE film, and increases the aesthetics of the product. The patterned part can also have product recognition (such as using trademark patterns with intellectual property rights). The local uneven surface formed by the pattern bonding can also help increase the surface area of ​​the material, thereby enhancing the bonding strength between the composite high-permeability material and other materials when it is subsequently bonded with other materials to form sanitary products. Attached Figure Description

[0099] Figure 1 This is a structural diagram of the highly breathable composite fiber product of the present invention; it is a structural diagram of the product in Example 1;

[0100] Figure 2 This is a front view of the first impermeable substrate (3) of the present invention;

[0101] Figure 3 Cross-sectional view of the impermeable bottom layer (3) of the present invention

[0102] Figure 4 This is a product structure diagram of Example 2;

[0103] Figure 5 This is a product structure diagram of Example 3;

[0104] Figure 6 This is a product structure diagram of Example 4;

[0105] Figure 7 This is the product structure diagram for comparison with Example 5;

[0106] Figure 8 This is another embossed pattern for the liquid-impermeable underlayer of the present invention; (straight lines)

[0107] Figure 9 This is another embossed pattern for the liquid-impermeable underlayer of the present invention; (circular lines).

[0108] Figure 10 This is the embossed pattern on the impermeable substrate of Example 2; (intersecting diamond grids)

[0109] Figure 11 Embossed patterns with impermeable liquid underlayers are not recommended; (forked)

[0110] Figure 12 Embossed patterns with impermeable liquid substrates are not recommended; (discontinuous lines)

[0111] Figure 13 This is the embossed pattern on the impermeable substrate of Example 3; (pressed vs. unpressed = 5:1)

[0112] Figure 14 This is a schematic diagram of the product used in the present invention for leak-proof edge separation;

[0113] Figure 15 It is the embossed pattern compared to Example 8;

[0114] 1. Liquid-permeable top layer; 2. Absorbent core; 3. First liquid-impermeable bottom layer; 4. Second liquid-impermeable bottom layer; 5. Urine indicator adhesive; 6. EPTFE membrane; 7. First nonwoven fabric; 8. Adhesive part; 9. Non-adhesive part / unbonded part; 10. Second nonwoven fabric; 11. Leak-proof side panel. Detailed Implementation

[0115] This invention utilizes EPTFE microporous membranes and their composite membranes. The EPTFE membrane has an air permeability of 1-600 mm / s (pressure 127 Pa), with a preferred air permeability of 100-300 mm / s, which is tens to 2500 times higher than the air permeability of conventional PE breathable membranes (approximately 0.2 mm / s). Absorbent products made from composite membranes with an air permeability exceeding 80 mm / s have an air permeability more than 400 times that of conventional breathable PE membranes.

[0116] Example 1

[0117] like Figure 1 The diagram shows the structure of the high-breathability composite fiber product of the present invention. The diaper includes a liquid-permeable top layer 1, a liquid-impermeable bottom layer 3, and an absorbent layer 2 sandwiched between the top and bottom layers. Each layer is formed integrally from top to bottom by a lamination and bonding method. The liquid-permeable top layer 1 is made of hot-air nonwoven fabric with a surface layer basis weight of 40 g / m². 2The core is a prefabricated composite core with a density of 480 g / m², and its structure is non-woven fabric / absorbent powder / fluffy cotton / absorbent powder / non-woven fabric. The impermeable bottom layer uses a layer of EPTFE membrane 6 and a layer of non-woven fabric 7 (SMMS). The non-woven fabric is heat-pressed together with non-intersecting wavy patterns. (EPTFE has a smooth surface and is not easily bonded; the embossing creates an uneven surface while forming an adhesive, which also helps to achieve higher bonding strength when using it as a breathable material in absorbent products to bond other materials with adhesives.) Alternatively, the wavy pattern can be replaced with straight lines or circular patterns, such as... Figure 8 and Figure 9 As shown in the figure, the wavy pressing lines have a uniform width of 1mm and are interspersed with 3mm unpressed portions (adhesive portion 8 and non-adhesive portion / unadhesive portion 9 in the figure). The ratio of the pressed area of ​​the wavy lines to the area of ​​the unpressed portions is 1:3. The maximum curvature at each bend of the wavy lines is also 10m. -1 The following (radius of curvature 0.1m): The EPTFE membrane is the same size as the SMMS nonwoven fabric; the liquid-impermeable bottom layer is laid flat below the absorbent layer of the diaper; the EPTFE membrane is on the side closest to the absorbent layer; the EPTFE membrane basis weight is preferably 2.0 g / m², and the SMMS nonwoven fabric basis weight is 13 g / m². 2 The liquid-impermeable underlayer has a printed pattern on its SMMS nonwoven fabric, with the printed pattern facing away from the core. The air permeability of the liquid-impermeable underlayer is 252.8 mm / s.

[0118] The mechanism and method for manufacturing highly breathable composite materials: a) Mechanism: includes a patterned roller and a smooth roller. The surface of the patterned roller has raised, non-crossing, non-branching, uninterrupted, smooth, continuous linear patterns (the pattern shape should correspond to the shape of the corresponding adhesive part). Both the patterned roller and the smooth roller are equipped with temperature-adjustable heating devices. The patterned roller and the smooth roller cooperate to form a pressing bond. The patterned roller and the smooth roller rotate in opposite directions. A pressure device, such as hydraulic pressure, can be added to increase the pressure between the two rollers. Additional adhesive devices, such as ultrasonic waves, can also be added to enhance the bonding effect. b) Method: After the EPTFE film and nonwoven fabric are unwound separately, they are bonded together by electrostatic adsorption. The bonded materials are then passed together through a patterned roller and a smooth roller to form a hot-press bond. During hot-press bonding, if a heating method is used, the temperature can be controlled between 90-150℃. If ultrasonic bonding is used, the temperature of the patterned roller can be controlled within the range of 70-110℃, the ultrasonic power can be controlled to 1-3 kW, and the vibration frequency can be controlled within 10000-30000 Hz. When applying pressure, the pressure range is adjusted to 4KG-40KG. The electrostatic adsorption bonding before hot-press bonding ensures the flatness of the material and can also reduce or avoid the narrowing of the particularly thin EPTFE film due to tensile shrinkage, thereby reducing or avoiding the reduction of the air permeability and width of the composite material. In this embodiment, the manufacturing parameters used are hot-press bonding, temperature 95-100℃, ultrasonic power 2kW, frequency 20KHz, pressure of about 20-25Kg, and equipment operating speed of 40-50 meters / minute.

[0119] Comparative Example 1

[0120] The only difference between Comparative Example 1 and Example 1 is that the liquid-impermeable bottom layer of the diaper is a conventional PE breathable membrane with added calcium carbonate. The air permeability of the PE breathable membrane is 0.2 mm / s.

[0121] Comparative Example 2

[0122] The only difference between Comparative Example 2 and Example 1 is that the liquid-impermeable bottom layer of the diaper is a heat-pressed composite of EPTFE and SMMS, with the composite pattern being... Figure 10 The grid pattern shown has angles of approximately 75-80° within it.

[0123] Comparative Example 3

[0124] The only difference between Comparative Example 3 and Example 1 is that the liquid-impermeable bottom layer of the diaper is a heat-pressed composite of EPTFE and SMMS, with the ratio of the pressed portion area to the unpressed portion area being 5:1. The composite pattern is as follows. Figure 13 As shown.

[0125] The air permeability of Example 1 and Comparative Example 1 was tested according to the test method of GB / T 5453, and the results are shown in Table 1.

[0126] Table 1

[0127] As shown in Table 1, under the premise of no leakage, the breathability test of diapers shows that replacing the PE calcium carbonate breathable membrane with EPTFE high breathability composite material improves the breathability of the product by about 1000 times.

[0128] The leakage of diapers in Example 1 and Comparative Example 2 was tested according to the national standard GBT28004.1. The leakage included water vapor leakage and liquid leakage. The national standard requires that the leakage amount be less than 1 gram to be qualified. The data are shown in Table 2.

[0129] Table 2

[0130] As shown in Table 2, the leakage of the high-permeability composite material described in Example 1 is within acceptable limits, while the leakage of the high-permeability composite material in Comparative Example 2 exceeds the standard. In other words, the cross-patterned hot-press bonding results in excessive leakage, mainly due to damage to the composite film at the intersection points, leading to liquid leakage at the damaged areas and causing the product to fail the leakage test.

[0131] The air permeability of Example 1 and Comparative Example 3 was tested according to the test method of GB / T 5453, and the results are shown in Table 3.

[0132] Table 3

[0133]

[0134] As can be seen from Table 3, the air permeability of the high-permeability composite material with a hot-pressed bonded area: unbonded area ratio of 1:3 described in Example 1 is much higher than that of the high-permeability composite material with a hot-pressed bonded area: unbonded area ratio of 5:1 described in Control Example 3.

[0135] Example 2

[0136] This embodiment provides a highly breathable sanitary napkin, such as Figure 4 As shown.

[0137] The sanitary napkin comprises a liquid-permeable top layer, a liquid-impermeable bottom layer, and an absorbent layer sandwiched between the top and bottom layers, all layers being laminated and bonded together from top to bottom. The sanitary napkin also includes an adhesive backing and an adhesive release liner.

[0138] The liquid-permeable top layer is made of hot-air nonwoven fabric with a basis weight of 24 g / m³. 2 .

[0139] The absorbent layer is a mixture of wood pulp fiber and superabsorbent polymer.

[0140] The impermeable bottom layer adopts a three-layer structure with EPTFE as the middle layer: SSMMS / EPTFE membrane / SSMMS, and the three layers are made of... Figure 4 The product structure shown is formed by hot-pressing and lamination, with the liquid-impermeable bottom layer laid flat beneath the absorbent layer of the sanitary napkin. The SSMMS has a basis weight of 7 g / m², and the EPTFE membrane has a basis weight of 1.5 g / m². The air permeability of the SSMMS is approximately 3600 mm / s, the air permeability of the 1.5 g EPTFE membrane is 160 mm / s, and the air permeability of the liquid-impermeable bottom layer is 122.0 mm / s.

[0141] Comparative Example 4

[0142] The difference between Comparative Example 4 and Example 2 is that the liquid-impermeable bottom layer of the sanitary napkin is a conventional PE breathable membrane with added calcium carbonate. The air permeability of the PE breathable membrane is 0.2 mm / s.

[0143] Example 2 and Comparative Example 4 were tested for air permeability according to the test method of GB / T 5453, and the results are shown in Table 4.

[0144] Table 4

[0145]

[0146] Comparing Table 4, it can be seen that, based on the premise of no leakage, the air permeability test of sanitary napkins shows that replacing the PE calcium carbonate breathable membrane with an EPTFE high-breathability composite membrane improves the product's air permeability by approximately 610 times.

[0147] Example 3

[0148] This embodiment provides a highly breathable diaper, such as Figure 5 As shown.

[0149] The diaper comprises a liquid-permeable top layer, a first liquid-impermeable bottom layer, and an absorbent layer sandwiched between the top and bottom layers, with each layer being laminated and bonded together from top to bottom to form a single unit.

[0150] The liquid-permeable top layer is made of hot-air nonwoven fabric with a basis weight of 24 g / m². 2 ;

[0151] The core is a prefabricated composite core with a density of 480 g / m², and its structure is non-woven fabric / absorbent powder / fluffy cotton / absorbent powder / non-woven fabric.

[0152] The first liquid-impermeable bottom layer is made of an EPTFE membrane and an SMMS nonwoven fabric, which are hot-pressed together with non-intersecting wavy lines. The wavy lines are uniform in width and 1 mm wide, and the ratio of the wavy line pressing area to the non-pressed area is 1:3. The EPTFE membrane and the SMMS nonwoven fabric are the same size. The liquid-impermeable bottom layer is laid flat under the absorbent layer of the diaper. The EPTFE membrane is located on the side closest to the absorbent layer. Preferably, the EPTFE membrane has a basis weight of 2.0 g / m², and the SMMS nonwoven fabric has a basis weight of 13 g / m². 2 ;

[0153] Between the first impermeable liquid bottom layer and the core, there is a second impermeable liquid bottom layer 4 of 15g PP film. The water repellency of the second impermeable liquid bottom layer 4 is higher than that of the first impermeable liquid bottom layer. The side of the second impermeable liquid bottom layer 4 facing the core is coated with urine indicator adhesive 5. The urine indicator adhesive 5 consists of two adhesive strips with a width of 2 mm and a length of 280 mm.

[0154] Comparative Example 5

[0155] Comparative Example 5 Figure 7 As shown. The main difference between it and Example 3 is that Comparative Example 5 does not have a second impermeable liquid underlayer of PP membrane, and the urine indicator gel is directly coated on the EPTFE membrane.

[0156] Example 3 and Comparative Example 5 were tested for diaper leakage according to the national standard GBT28004.1. The leakage amount includes water vapor leakage and liquid leakage. The national standard requires that the leakage amount is less than 1 gram to be qualified. The data are shown in Table 5.

[0157] Table 5

[0158]

[0159] As shown in Table 5, the leakage of the high-permeability composite membrane described in Example 3 is within acceptable limits, while the leakage of the composite breathable membrane used in Comparative Example 5 exceeds the standard. The main components of the urine indicator gel used in the test experiment include: matrix resin, and 10% by weight of the matrix resin surfactant polyvinylpyrrolidone and 0.5% by weight of the fluorescent humidity indicator.

[0160] Example 4

[0161] This embodiment provides a highly breathable diaper, such as Figure 6 As shown.

[0162] The diaper comprises a liquid-permeable top layer, a liquid-impermeable bottom layer, and an absorbent layer sandwiched between the top and bottom layers, which are sequentially laminated from top to bottom to form a single unit.

[0163] The liquid-permeable top layer is made of hot-air nonwoven fabric with a basis weight of 24 g / m². 2 ;

[0164] The core is a prefabricated composite core with a density of 480 g / m², and its structure is non-woven fabric / absorbent powder / fluffy cotton / absorbent powder / non-woven fabric.

[0165] The liquid-impermeable bottom layer is composed of an EPTFE membrane and an SMMS nonwoven fabric, bonded together by hot pressing with non-intersecting wavy lines. The wavy lines have a uniform width of 1 mm, and the ratio of the wavy line bonding area to the non-bonded area is 1:3. The EPTFE membrane and the SMMS nonwoven fabric are the same size. The liquid-impermeable bottom layer is laid flat below the absorbent layer of the diaper, with the EPTFE membrane on the side closest to the absorbent layer. Preferably, the EPTFE membrane has a basis weight of 2.0 g / m², and the SMMS nonwoven fabric has a basis weight of 13 g / m². 2 ;

[0166] The SMMS nonwoven fabric layer of the liquid-impermeable bottom layer faces the core. Between the SMMS of the liquid-impermeable bottom layer and the core, there is a second layer of water-repellent nonwoven fabric SMMS. The side of the second water-repellent nonwoven fabric SMMS facing the core is coated with urine indicator adhesive. The urine indicator adhesive consists of a strip with a width of 1 mm and a length of 270 mm.

[0167] Example 4 and Comparative Example 5 were tested for diaper leakage according to the national standard GBT28004.1. The leakage amount includes water vapor leakage and liquid leakage. The national standard requires that the leakage amount is less than 1 gram to be qualified. The data are shown in Table 6.

[0168] Table 6

[0169]

[0170] As can be seen from Table 6, the leakage of the high-permeability composite material described in Example 4 is within acceptable limits, while the leakage of the composite permeable material in Comparative Example 5 exceeds the standard.

[0171] Example 5

[0172] This embodiment provides a high-permeability composite material, which adopts a three-layer structure with EPTFE as the middle layer: SSMMS / EPTFE membrane / SSMMS. The three layers are formed by patterned hot pressing. The high-permeability composite material consists of one layer of SSMMS, one layer of EPTFE membrane, and one layer of SSMMS nonwoven fabric, which are hot-pressed together with non-intersecting wavy lines. The width of the wavy pressing lines is consistent and 1 mm. The ratio of the pressing area of ​​the wavy lines to the non-pressed area is 1:3. The EPTFE membrane and the SSMMS nonwoven fabric are the same size. The basis weight of the SSMMS is 7 g / m², and the basis weight of the EPTFE membrane is 2.0 g / m². The total basis weight of the high-permeability composite material is 16.0 g / m².

[0173] The air permeability of the SSMMS tested at 200K pressure was approximately 3600 mm / s, while the air permeability of the 2.0 g EPTFE membrane was 120 mm / s.

[0174] Comparative Example 6: 16.0 g / m² calcium carbonate PE breathable membrane.

[0175] Table 7 Comparison of air permeability under different air pressure differences (tested according to GB / T 5453):

[0176]

[0177] Note: The comparative test data in Table 7 show that the greater the pressure difference between the two sides of the high-permeability composite fiber material described in this invention, the higher its air permeability.

[0178] Table 8 Comparison of moisture permeability under different temperature differences

[0179]

[0180] Note: As can be seen from the data in Table 8, the higher the water temperature (the greater the temperature difference between the two sides of the material), the higher the moisture permeability in the same time period, which means the higher the water vapor permeability; the higher the water temperature (the greater the temperature difference between the two sides of the material), the more heat permeates through the highly breathable composite fiber material in the same time period (the greater the temperature change on the other side of the material).

[0181] Test method:

[0182] Experimental conditions: 1. Absorbency – Approximately 1g of SAP was wrapped in Vinda facial tissue (super tough S size, one sheet - about 1g) as absorbent material.

[0183] 2. Fill the support base under the membrane with 250ml of hot water.

[0184] 3. The temperature gun is approximately 2cm away from the water source and the top and bottom edges of the membrane, used for evaluating heat dissipation effect.

[0185] 4. After adding hot water, seal the bottle opening with the lid for 1 minute to ensure the humidity at the bottle opening reaches 100% before testing.

[0186] 5. Bottle mouth diameter: 80mm.

[0187] Experimental steps: 1. Adjust the water bath temperature to 50 / 80℃ and maintain a constant temperature.

[0188] 2. Add 250ml of hot water to the lower base and seal it with a round cover for 1 minute to reach 100% humidity. Then remove the round cover, cover with the membrane material and moisture-absorbing material (membrane material at the bottom), and close the support frame.

[0189] 3. Secure the upper support (to avoid interference from other environments), remove the absorbent material after absorbing moisture for 2 minutes, and weigh it.

[0190] 4. At the 6th minute of the experiment, use a temperature gun to measure the water temperature at the base, the temperature at the lower end of the membrane connection (horizontal direction), and the temperature at the upper end of the membrane (from top to bottom). The measurement distance is 2cm.

[0191] Table 9 Comparative data on changes in moisture permeability under different humidity differences and under pressure.

[0192]

[0193] Note: As can be seen from the data in Table 9:

[0194] 1. The greater the humidity difference between the two sides of a composite high-permeability material, the higher the humidity transmittance per unit time period:

[0195] In Example 5, the high-permeability composite fiber material, without pressure, initially had humidity levels of 100% and 53.4% ​​on both sides of the material, with a humidity difference of 46.6%. During the 0-5 second time period, the humidity change rate at the top of the composite material was 4.30% / min. At the 5-second starting point, the humidity levels on both sides of the material were 100% and 74.9%, with a humidity difference of 25.1%. During the 5-20 second time period, the humidity change rate at the top of the composite material was 1.26% / min. In other words, the humidity change rate during the 0-5 second time period with a large humidity difference was higher than the humidity change rate during the 5-10 second time period with a small humidity difference.

[0196] 2. When the humidity difference between the two sides of a composite high-permeability material is constant, the greater the pressure difference, the higher the humidity transmittance per unit time period.

[0197] In Example 5, the high-permeability composite fiber material, under pressure, initially had humidity levels of 100% and 53.9% on both sides of the material, with a humidity difference of 46.1%. Within a 0-20 second time period, the humidity change rate at the upper end of the composite material was 4.61% / min. In Example 5, without pressure, the high-permeability composite fiber material, initially had humidity levels of 100% and 53.4% ​​on both sides of the material, with a humidity difference of 46.6%. Within a 0-20 second time period, the humidity change rate at the upper end of the composite material was 2.04% / min.

[0198] 3. In comparison with the calcium carbonate PE breathable membrane of Comparative Example 6, the high breathability composite fiber material of Example 5 showed higher moisture permeability under both pressurized and unpressurized conditions.

[0199] As shown in Table 9, under unpressurized conditions, the air permeability change of the high-permeability composite fiber material in Example 5 from 0 to 20 seconds was 2.04% / min, while the air permeability change of the calcium carbonate PE membrane in Comparative Example 6 was 1.83% / min. The air permeability change of the high-permeability composite fiber material was higher than that of the calcium carbonate PE membrane.

[0200] As shown in Table 9, under pressure, the air permeability of the high-permeability composite fiber material in Example 5 changed by 4.61% / min from 0 to 20 seconds, while the air permeability of the calcium carbonate PE membrane in Comparative Example 6 changed by 2.31% / min. The air permeability change of the high-permeability composite fiber material is almost twice that of the calcium carbonate PE membrane.

[0201] With good moisture permeability and breathability, it is conducive to the expulsion and cooling of hot and humid air, and also allows cool air from the outside to enter the absorbent product to lower its internal temperature, thereby effectively reducing or eliminating allergy problems such as diaper rash and inflammation, and meeting the needs of consumers.

[0202] Comparative Example 7

[0203] This comparative example provides a high-permeability composite material, which adopts a three-layer structure with EPTFE as the middle layer: SSMMS / EPTFE membrane / SSMMS. The three layers are stacked together. The basis weight of SSMMS is 7 g / m², the basis weight of EPTFE membrane is 2.0 g / m², and the total basis weight of the high-permeability composite material is 16.0 g / m².

[0204] The only difference between Comparative Example 7 and Example 5 is that patterned hot-press bonding was not performed between the layers.

[0205] Table 10

[0206]

[0207] As shown in Table 10, the stabilizing blood pressure resistance of Example 5 was approximately 63% higher than that of Comparative Example 7. Higher stabilizing blood pressure resistance indicates better leakage prevention and blood-water blocking effects, demonstrating that the striped laminated high-permeability composite material of this invention has better leakage prevention and blood-water blocking effects than simple lamination. This is especially important for high-permeability leak-proof side panels or bottom layers. The stabilizing blood pressure resistance (artificial menstrual blood) test method is based on GB / T4744-2013.

[0208] Example 6

[0209] This embodiment provides a highly breathable composite material:

[0210] A three-layer structure with EPTFE as the middle layer is adopted: SSMMS / EPTFE membrane / SSMMS, wherein the three layers are made of... Figure 13The pattern shown is formed by hot pressing and lamination; the SSMMS has a basis weight of 7 g / m², and the EPTFE membrane has a basis weight of 1.0 g / m². The air permeability of the SSMMS is approximately 3600 mm / s, and the air permeability of the 1.0 g EPTFE membrane is 200 mm / s.

[0211] Comparative Example 8

[0212] The only difference between Comparative Example 8 and Example 6 is the use of Figure 15 The pattern shown is formed by hot pressing. Figure 15 The radius of the arc in the diagram is R = 1.5 mm.

[0213] The leakage rate of Example 6 and Comparative Example 8 was tested according to the national standard GB / T28004.1 and the hydrostatic pressure resistance was tested according to the national standard GB / T4744-2013. The data are shown in Table 11.

[0214] Table 11

[0215]

[0216] Data shows that Example 6 has a higher hydrostatic pressure resistance than Comparative Example 8, and the leakage of Example 6 is lower than that of Comparative Example 8. This difference is mainly due to the fact that the embossed pattern of Comparative Example 8 has many small local arc radii at bends, which form many stress concentration points, vulnerable points (local) and local damage points after hot pressing. During pressure testing and leakage testing, these vulnerable points and damaged local areas are more likely to allow liquid to penetrate, thereby reducing the hydrostatic pressure resistance and increasing the leakage.

[0217] Comparative Example 9

[0218] The only difference between Comparative Example 9 and Example 6 is that Comparative Example 9 uses... Figure 11 The pattern shown is formed by hot pressing. Figure 11 The angle between the branching dendrites in the diagram is α = 30 degrees.

[0219] The leakage rate of Example 6 and Comparative Example 9 was tested according to the national standard GB / T28004.1 and the hydrostatic pressure resistance was tested according to the national standard GB / T4744-2013. The data are shown in Table 12.

[0220] Table 12

[0221]

[0222] Data shows that Example 6 has a higher hydrostatic pressure resistance than Comparative Example 9, and the leakage of Example 6 is lower than that of Comparative Example 9. This difference is mainly due to the fact that the embossed pattern of Comparative Example 9 has many branches and the included angle of the branches is too small. After hot pressing and bonding, many stress concentration points, vulnerable points (local) and local damage points are formed. During pressure test and leakage test, these vulnerable points and damaged local areas are more likely to form liquid penetration, thereby reducing the hydrostatic pressure resistance and increasing the leakage.

[0223] Comparative Example 10

[0224] To compare with the thermal bonding method in Example 1, a conventional roller-to-roller thermal bonding process was used to manufacture EPTFE / SMMS nonwoven composite fiber material. The processing method and parameters included one heated roller and the other a flexible, unheated roller. The equipment operating speed was 40-50 meters per minute, the temperature of the heated roller was 280-350°C, and the inter-roller pressure was 4-8 kg.

[0225]

[0226] As can be seen, when using the thermal bonding method via a patterned roller as described in this invention, the EPTFE film and nonwoven fabric can be bonded together at a lower temperature and with localized bonding, significantly reducing the possibility of the nonwoven fabric clogging the micropores of the EPTFE during bonding. This avoids a significant decrease in the air permeability of the EPTFE film. In contrast, if the two layers are bonded using a traditional method of bonding the entire area of ​​the roller to the nonwoven fabric, heat needs to penetrate the EPTFE film through the heated roller to melt the nonwoven fabric surface and form an adhesive, thus requiring a higher temperature. The temperature required to achieve composite strength at a certain speed is even higher, causing the material to melt and clog the EPTFE membrane. Commonly used nonwoven fabrics are basically made of PET, PP and PE or combinations thereof, with melting points of around 260℃, 160℃ and 120℃, respectively, while the melting point of EPTFE is around 327℃. The traditional full-area bonding method of light roller to light roller is also not suitable for bonding three layers of nonwoven fabric / EPTFE membrane / nonwoven fabric, because the melting point of nonwoven fabric is much lower than that of EPTFE. Nonwoven fabric that directly contacts the high-temperature heat roller will completely melt, making it impossible to obtain a three-layer composite material.

Claims

1. A disposable, highly breathable composite fiber material, characterized in that, It includes a liquid-permeable top layer (1), an absorbent core (2), and a first liquid-impermeable bottom layer (3) stacked in sequence; The first impermeable bottom layer (3) contains a highly permeable composite material; The high-permeability composite material includes an EPTFE membrane (6) and a first nonwoven fabric (7) stacked sequentially, and the EPTFE membrane (6) and the first nonwoven fabric (7) are bonded and fixed together by multiple adhesive parts (8). The ratio of the total projected area of ​​the multiple adhesive parts (8) on the first liquid-impermeable bottom layer (3) to the non-adhesive area outside the adhesive parts is 3:1-1:

20. A urine indicator gel (5) is also provided between the first impermeable bottom layer (3) and the absorbent core (2); The EPTFE membrane (6) faces the absorbent core (2); or, the first nonwoven fabric (7) faces the absorbent core (2). It also includes a second impermeable bottom layer (4), located between the first impermeable bottom layer (3) and the absorbent core (2), and a urine indicator gel (5) is also provided between the second impermeable bottom layer (4) and the absorbent core (2); The plurality of adhesive portions (8) are distributed on the first impermeable bottom layer (3), and there are no connecting parts between adjacent adhesive portions; The projection shape of the adhesive part (8) on the first impermeable bottom layer (3) is any one of the following: curved, broken, straight, ring, circular, elliptical or a combination thereof; When the projected shape is curved, the curvature at any bend in the curve must be less than 400m. -1 When the projected shape is a broken line, the included angle between any two adjacent line segments must be greater than 120°; when the projected shape is a circle, the radius must be greater than 0.0025m; when the projected shape is an ellipse, the curvature of any point on the arc of the ellipse must be less than 400m. -1 ; When the projected shape is annular, any point within the annulus satisfies a curvature less than 400m. -1 .

2. The disposable high-permeability composite fiber material according to claim 1, characterized in that, The water repellency of the first nonwoven fabric (7) is lower than that of the EPTFE membrane (6); the air permeability of the first nonwoven fabric (7) is higher than that of the EPTFE membrane (6).

3. The disposable high-permeability composite fiber material according to claim 1, characterized in that, The air permeability of the first nonwoven fabric (7) and the EPTFE membrane (6) is higher than that of the first liquid-impermeable bottom layer (3).

4. The disposable high-permeability composite fiber material according to claim 1, characterized in that, The projection shape of the adhesive portion (8) on the first impermeable bottom layer (3) is continuous; there is no connection between adjacent adhesive portions (8).

5. The disposable high-permeability composite fiber material according to claim 1, characterized in that, The line width of the adhesive part (8) is 0.1 mm. -1 0mm; the distance between the lines of adjacent adhesive parts (8) is 0.1mm-200mm.

6. The disposable high-permeability composite fiber material according to claim 1, characterized in that, The first liquid-impermeable bottom layer (3) also includes a second nonwoven fabric (10) located on the side of the EPTFE membrane (6) opposite to the first nonwoven fabric (7).

7. The disposable high-permeability composite fiber material according to claim 1, characterized in that, The first nonwoven fabric is a water-repellent nonwoven fabric; The water-repellent nonwoven fabric is one of the following: hot air nonwoven fabric, hot-rolled nonwoven fabric, spunlace nonwoven fabric, SS spunbond nonwoven fabric, SMS nonwoven fabric, SMMS nonwoven fabric, or nonwoven fabric composed of multiple layers of S and multiple layers of M, or a composite nonwoven fabric thereof. The EPTFE membrane (6) has a thickness of 0.0001 mm to 1 mm and an air permeability of 1-600 mm / s.

8. The disposable high-permeability composite fiber material according to claim 6, characterized in that, The second nonwoven fabric is a water-repellent nonwoven fabric; the water-repellent nonwoven fabric is one of the following: hot-air nonwoven fabric, thermally rolled nonwoven fabric, spunlace nonwoven fabric, SS spunbond nonwoven fabric, SMS nonwoven fabric, SMMS nonwoven fabric, or a nonwoven fabric composed of multiple layers of S and multiple layers of M, or a composite nonwoven fabric thereof.

9. The disposable high-permeability composite fiber material according to claim 6, characterized in that, The EPTFE membrane (6) has a thickness of 0.0001 mm to 1 mm and an air permeability of 1-600 mm / s. The air permeability of the first nonwoven fabric is greater than or equal to the air permeability of the second nonwoven fabric, and their air permeability is greater than that of the EPTFE membrane.

10. The disposable high-permeability composite fiber material according to claim 6, characterized in that, The second nonwoven fabric (10) is bonded and fixed to the EPTFE film (6) through the adhesive part (8).

11. The disposable high-permeability composite fiber material according to claim 1, characterized in that, It also includes a leak-proof partition (11), wherein the leak-proof partition (11) contains the high-permeability composite material; The liquid-permeable top layer (1) is a nonwoven fabric obtained by one of hot air nonwoven fabric, hot-rolled nonwoven fabric, spunlace nonwoven fabric, spunbond nonwoven fabric or a combination thereof; The absorbent core (2) contains a water-absorbing polymer material; The absorbent core (2) is made of water-absorbing polymer combined with wood pulp fiber, non-woven fabric, fluffy cotton or dust-free paper.

12. A sanitary product comprising the disposable highly breathable composite fiber material as described in claim 1.

13. The sanitary product according to claim 12, characterized in that, The sanitary products mentioned include baby diapers, adult diapers, incontinence pads, nursing pads, mattresses, diaper changing pads, sanitary napkins, menstrual pants, sanitary pads, maternity pads, or breast pads.

14. A method for manufacturing the disposable high-breathability composite fiber material according to any one of claims 1-5, characterized in that, The manufacturing of the high-permeability composite material includes the following steps: pressing the EPTFE film (6) and the first nonwoven fabric (7) together with the light roller or the second patterned roller through the first patterned roller, and fixing them by hot pressing, ultrasonic pressing or a combination thereof; the first patterned roller and the second patterned roller include patterned protrusions protruding from the surface of the roller and used to form the adhesive portion.

15. The manufacturing method according to claim 14, characterized in that, It also includes steps for adjusting the pressure, temperature, speed, and gap between the patterned roller and the smooth roller.

16. The manufacturing method according to claim 14, characterized in that, If hot pressing is used for bonding, the temperature should be controlled between 90-150℃. If ultrasonic bonding is used, the temperature of the patterned roller should be controlled between 70-110℃, the ultrasonic power should be controlled between 1-3 kilowatts, the vibration frequency should be controlled between 10000-30000 Hz, and when pressure is applied, the pressure range should be adjusted between 4kg-40kg.

17. The manufacturing method according to claim 14, characterized in that, Before the shaping and bonding are fixed, the process also includes a step of stacking the EPTFE film (6) and the first nonwoven fabric (7) by electrostatic bonding.

18. The manufacturing method according to claim 14, characterized in that, During lamination, the EPTFE surface faces the patterned roller, and the nonwoven fabric surface faces the smooth roller; this ensures that the pattern shape and position area of ​​the two layers are consistent, and the raised height of the EPTFE material's pattern is higher than that of the nonwoven fabric.

19. The processing apparatus for the disposable high-permeability composite fiber material according to any one of claims 1-5, characterized in that, The processing equipment for high-permeability composite materials includes: First patterned roller; And a matching roller, wherein the matching roller is a second patterned roller or a smooth roller; The first patterned roller and the matching roller work together to bond and laminate the EPTFE film and the first nonwoven fabric, or to bond and laminate the second nonwoven fabric, the EPTFE film and the first nonwoven fabric, to form a disposable high-permeability composite material with an adhesive part. The area ratio of the raised to the recessed areas on the first and second patterned rollers is 3:1 to 1:

20. The planar projection shape of the raised pattern is any one of the following: curved, broken, straight, ring, circle, ellipse, or a combination thereof; When the projected shape is curved, the curvature at any bend in the curve must be less than 400m. -1 When the projected shape is a broken line, the included angle between any two adjacent line segments must be greater than 120°; when the projected shape is a circle, the radius must be greater than 0.0025m; when the projected shape is an ellipse, the curvature of any point on the arc of the ellipse must be less than 400m. -1 When the projected shape is annular, any point within the annulus satisfies a curvature less than 400m. -1 ; The planar projection shape is continuous; there is no connection between adjacent patterned protrusions. The raised lines of the pattern are 0.1mm wide. - 10mm; the distance between adjacent raised lines of the pattern is 0.1mm-200mm.

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