High water-absorbing resin composite cloth and method for manufacturing the same

Abstract

The application discloses a high water-absorbing resin composite cloth, which comprises an outer layer 1, an inner layer 2 and an intermediate layer 3, characterized in that the intermediate layer 3 is composed of a three-dimensional net structure 4, the three-dimensional net structure 4 comprises irregular net accommodation spaces 5 which are interconnected, and high water-absorbing resin powder 6 is accommodated in the accommodation spaces 5. The application solves the technical bottleneck that sodium polyacrylate resin powder is used as a heat insulation material in the prior art, and enables the sodium polyacrylate resin powder to continuously and uniformly form a firm and non-falling gel heat insulation layer in the heat insulation cloth.

Description

Technical Field

[0001] This invention relates to the field of flame-retardant and heat-insulating fire protection equipment technology, specifically to a highly absorbent resin composite fabric and its manufacturing method. Background Technology

[0002] In current technology, water remains the most commonly used fire extinguishing agent, offering advantages such as low cost, easy availability, and no environmental pollution. However, in the field of fire-resistant and heat-insulating fabrics, water is rarely used as an insulation medium. Traditional fire-resistant and heat-insulating materials typically use metals, ceramics, and fibers as the base of composite materials, utilizing the inherent fire-resistant and heat-insulating properties of the materials themselves to achieve the protective task. However, the actual heat insulation effect of this type of protective material is not ideal. The intense burning sensation upon entering a fire greatly affects the wearer, and the materials are also very heavy, expensive, and complex to manufacture, making them unsuitable for everyday household use or as standard fire-fighting equipment in less important situations.

[0003] Superabsorbent resin (SAR) is a novel functional polymer material containing strongly hydrophilic groups such as carboxyl and amide groups, and exhibiting a certain degree of cross-linking. It is water-swellable and possesses a three-dimensional network structure, with sodium polyacrylate as a representative example. It is insoluble in water and organic solvents, and possesses unique properties—strong water absorption and water retention. Compared to traditional absorbent materials such as sponges, cotton, cellulose, and silica gel, SAR has a much larger water absorption capacity, capable of rapidly absorbing tens or even thousands of times its own weight in liquid water. It also exhibits strong water retention, resisting water loss even under heat and pressure, while retaining some characteristics of polymer materials. Due to these characteristics, research and development of SAR has been extremely rapid, and it has been widely applied in numerous fields, including agriculture, forestry, horticulture, medical and health care, food industry, petrochemicals, and building materials.

[0004] Superabsorbent polymers have developed rapidly and come in many varieties. There are also many ways to classify them. They are mainly classified according to the source of raw materials, hydrophilization method, type of hydrophilic groups, crosslinking method and product form. The most commonly used classification method is based on the source of raw materials, including starch-based superabsorbent polymers, cellulose-based superabsorbent polymers, synthetic superabsorbent polymers, protein-based superabsorbent polymers, and blended and composite superabsorbent polymers.

[0005] Superabsorbent polymers (SAPs) can absorb hundreds or even thousands of times their own weight in water because they possess two key characteristics: first, they have hydrophilic groups such as carboxyl, hydroxyl, amide, and sulfonic acid groups, making water absorption possible; second, they have a three-dimensional network structure that makes them insoluble in water, further enhancing their water absorption capabilities. SAPs are three-dimensional network polymers with hydrophilic groups and slight cross-linking. They can absorb large amounts of water and swell while retaining the water, exhibiting advantages such as high water absorption rate, rapid absorption, and strong water retention. Applying superabsorbent polymers, especially polyacrylic acid-based superabsorbent polymer hydrogels, to firefighting and emergency response fields offers the following advantages:

[0006] 1. In superabsorbent polymers, the side groups of the polymeric electrolyte ionize upon contact with water, releasing corresponding anionic hydrophilic groups and cations (mobile ions). The backbone of the main chain consists entirely of negatively charged anions, which are immobile. The repulsive forces between them generate the driving force for network expansion. Although the cations possess a certain degree of mobility, they are attracted and bound by the opposite charge of the network backbone, thus remaining within the network. This results in a higher cation concentration inside the network than in the external water, creating osmotic pressure between the ions and the network. Furthermore, because the polyelectrolyte itself has highly hydrophilic groups, water can enter the three-dimensional network in large quantities within a very short time. Under high-temperature conditions, superabsorbent polymers with a large amount of fixed free water have a considerable heat capacity. When water is lost, a large amount of heat is consumed, effectively isolating the heat source and protecting personnel safety in large fires.

[0007] 2. After absorbing water, the superabsorbent resin forms an elastic gel. The gel particles are tightly connected together, with no gaps between them that allow air to enter. In its hydrogel state, it can isolate the fire source from the air, protecting objects in the fire scene that have been covered by the gel, thereby achieving the effect of completely isolating the fire source and personnel.

[0008] 3. After absorbing water, the superabsorbent resin forms a gel with excellent chemical stability, thermal stability and compatibility. It also has very high viscosity and good adhesion, which allows it to cover the surface of objects without falling off and form a sufficient adhesion thickness, effectively improving the heat insulation effectiveness of unburned objects in a fire.

[0009] 4. The superabsorbent polymer is a powder that is safe in terms of storage and transportation. Its stability during storage (sealed to prevent water absorption) is more than two years and it is non-toxic. In a strong fire, the resin burns into carbon dioxide and water after losing water due to heat, which is non-toxic to humans and animals. After the fire is extinguished, the residual resin will degrade naturally within a few months, which is non-toxic and pollution-free to humans and the environment, making it green and environmentally friendly.

[0010] 5. Superabsorbent polymer (SAP) powder is lightweight and has an extremely strong water absorption capacity. It can absorb more than 300 times its own weight in water in a very short time. The resin powder content in the entire absorbent gel is generally between 0.05% and 0.5% of the water weight, usually around 0.1%. Only a small amount of SAP powder is needed to form a large amount of fire extinguishing gel, resulting in excellent fire extinguishing and fire prevention effects. It can continuously absorb moisture, avoiding secondary damage caused by excess water flowing around, and can absorb enough moisture in a short time to form a strong heat insulation effect.

[0011] In existing technologies, most superabsorbent resin fire extinguishing agents are mixed with water to extinguish open flames. This mixing method is unsuitable for everyday household use and does not provide suitable heat-insulating fabrics for everyday fire protection. To address these issues, existing technologies have developed solutions that incorporate powdered fire extinguishing agents into fire-resistant fabrics.

[0012] For example, existing technology discloses a fire-resistant layered structure comprising: a first base layer selected from fiber cloth; a superabsorbent layer covering at least one of the two surfaces of the first base layer, the superabsorbent layer being made of superabsorbent resin; and at least one second base layer selected from fiber cloth, the second base layer being disposed on the surface of the first base layer having the superabsorbent layer via a bonding unit, such that the superabsorbent layer is sandwiched between adjacent first and second base layers; thereby, the superabsorbent resin of the superabsorbent layer, after mixing with water, forms a gel-like water-retaining layer containing water particles, thus constituting a layered structure with good heat insulation and fire resistance. The bonding unit between the first and second base layers is an adhesive layer for supporting the layered structure. However, this protective material does not provide ideal fixation for the superabsorbent resin powder, especially after the outer nonwoven fabric is burned away by a high-temperature flame. The water-absorbing gel is not well fixed, resulting in flow or falling off, causing a significant decrease in heat insulation performance.

[0013] Prior art 2 discloses a fireproof layer comprising: a main body and multiple water-absorbing units; the main body includes a first base layer, a second base layer spaced apart from the first base layer, and multiple independent spaces disposed between the first base layer and the second base layer, wherein one of the first base layer and the second base layer of the main body is made of fireproof material, and the other of the first base layer and the second base layer of the main body has a water-permeable structure; the water-absorbing units are housed in the independent spaces; each water-absorbing unit includes a water-absorbing layer made of a water-absorbing polymer, and a water-permeable layer covering the water-absorbing layer, the water-absorbing layer having multiple water-absorbing polymer particles; the fireproof layer further includes an isolation layer disposed between the first base layer and the second base layer, and together with the first base layer and the second base layer, defines the independent spaces. However, this protective material focuses on fixing the resin before it absorbs water. It is not ideal for fixing highly absorbent resin powder, especially after the outer non-woven fabric is burned off by a high-temperature flame. The water-absorbing gel cannot be fixed well and may flow or fall off, resulting in a significant decrease in the heat insulation effect.

[0014] Existing technology 3 discloses a fire-retardant fabric comprising a non-woven fabric outer layer, a quilted fabric, and a non-woven fabric backing. The quilted fabric is sandwiched between the non-woven fabric outer layer and the backing, and sodium polyacrylate particles are distributed on the quilted fabric. The sodium polyacrylate particles are fixed between the non-woven fabric outer layer and the backing, and the non-woven fabric outer layer, quilted fabric, and backing are bonded together with adhesive. This invention focuses on the distribution of powder before water absorption, utilizing the friction of the quilted fabric and the adhesive to fix the resin powder between the outer and backing. This method causes the powder particles to concentrate on the surface of the quilted fabric, while reducing water permeability. This invention does not address the significant role of the intermediate spatial mesh structure in fixing the resin powder particles, resulting in undesirable particle migration and an unsatisfactory spatial distribution. After the flame burns through the outer layer of the non-woven fabric, the resin powder particles, lacking a supporting framework, will fall off after absorbing water. Once the airtightness is compromised, most of the heat insulation and flame-retardant properties will be lost.

[0015] In view of this, there is a need in the market for a composite fabric that can achieve rapid and controlled mixing of highly absorbent resin powder and water, and can keep the mixed gel stable in a designated position, especially after the outer fabric is burned by an open flame, so that the gel layer can be completely preserved on the outside of the inner fabric. Summary of the Invention

[0016] The technical problem to be solved by the present invention is to provide a superabsorbent resin composite fabric that can achieve rapid and controlled mixing of superabsorbent resin powder and water, and can continuously and stably maintain the mixed gel in a designated position.

[0017] The technical solution of the present invention is a highly absorbent resin composite fabric, comprising an outer layer 1, an inner layer 2, and a middle layer 3, characterized in that the middle layer 3 is composed of a three-dimensional mesh structure 4, the three-dimensional mesh structure 4 including interconnected irregular mesh accommodating spaces 5, and highly absorbent resin powder 6 is accommodated in the accommodating spaces 5.

[0018] Furthermore, the particle size of the superabsorbent resin powder 6, which accounts for more than 90% of the total weight of the superabsorbent resin powder 6, is controlled between 70 and 120 mesh, and the pore size of the three-dimensional mesh structure 4 is basically consistent with the controlled size of the superabsorbent resin powder 6 particles.

[0019] Furthermore, the strength of the three-dimensional mesh structure 4 of the intermediate layer 3 is configured to ensure that the three-dimensional mesh structure 4 has a thickness of at least 3 mm after being bonded with the outer layer 1 and the inner layer 2.

[0020] Furthermore, the outer layer 1, inner layer 2, and intermediate layer 3 are connected together by ultrasonic welding points 7.

[0021] Furthermore, the ultrasonic welding points 7 divide the heat insulation fabric into several relatively separated independent parts 8; the outer layer 1 has a flow channel 9, which is formed by the ultrasonic welding points 7.

[0022] Furthermore, the welding adhesion strength of the ultrasonic weld point 7 is set such that the ultrasonic weld point 7 is stretched open after the highly absorbent resin powder 6 absorbs water.

[0023] Furthermore, the outer layer 1 is made of hydrophilic nonwoven fabric with a pore size greater than 120 mesh, and the inner layer 2 is made of water-resistant nonwoven fabric.

[0024] Furthermore, the superabsorbent resin is a sodium polyacrylate copolymer.

[0025] Furthermore, the present invention also provides a method for manufacturing a superabsorbent resin composite fabric, used to manufacture the aforementioned composite fabric, comprising the following steps:

[0026] a. Control the size of the superabsorbent resin powder particles to be used to between 70-120 mesh;

[0027] b. The intermediate layer 3 is processed so that the three-dimensional mesh structure 4 of the intermediate layer 3 includes interconnected irregular mesh accommodating spaces 5, and the pore size of the three-dimensional mesh structure 4 is controlled to be basically consistent with the size of the superabsorbent resin powder 6 particles.

[0028] c. Temporarily fix the intermediate layer 3 to the inner layer 2;

[0029] d. Add highly absorbent resin powder 6 with a specified particle size to the intermediate layer 3, and stop adding the powder when the predetermined amount is reached;

[0030] e. During the feeding process, the inner layer 2 is horizontally vibrated to allow the powder to fully enter the irregular mesh-like accommodating space 5 of the three-dimensional mesh structure 4.

[0031] f. Cover the outer surface of the middle layer 3 with the outer layer 1;

[0032] g. The three-layer fabric structure is fixedly connected together using ultrasonic welding.

[0033] Furthermore, after step d, the outer surface of the intermediate layer 3 is subjected to hot air treatment, which causes the mesh structure of the three-dimensional mesh structure 4 to shrink and the surface pores to become smaller, thereby fixing the powder 6 relatively within the accommodating space 5.

[0034] Compared with the prior art, the advantages of the present invention are as follows:

[0035] 1. Reliable Fixation of Resin Powder. This invention further improves the structure of the intermediate layer, giving it interconnected containment channels. Unlike existing technologies, we place the highly absorbent resin powder into an interconnected spatial mesh structure as much as possible, and control the particle size to prevent fine powder from floating on the surface of the intermediate layer. On the one hand, in the unabsorbed state, the fiber-formed mesh can fix the powder particles, preventing them from moving freely and causing uneven powder distribution; on the other hand, in the absorbent state, the interconnected spaces allow the expanded gel formed after water absorption to move relatively, bonding more tightly together to form a sealed, airtight, and thick three-dimensional heat-insulating protective layer. Because if the heat-insulating layer is too thin, it is easy to have defects such as poor air permeability and weak adhesion, seriously affecting the flame-retardant and heat-insulating effect.

[0036] 2. Unaffected by outer layer burn-through. In our experiments, we frequently encountered flames exceeding 1000 degrees Celsius directly burning the outer layer of the protective fabric, almost always resulting in damage or complete loss of the outer layer. With traditional intermediate layers, because the gels lack a connecting "skeleton" and are merely squeezed together, the fabric surface peels off, causing the gel to fall off and creating areas without gel protection. These areas burn through very quickly, leading to failure of thermal insulation. With this invention, the dense mesh structure inside and on the surface of the gel strengthens the overall integrity of the gel layer, forming a gel layer across the entire surface of the fabric. This prevents premature burn-through at weak points, a crucial advantage in fire situations, as a breach in one area renders the integrity of the rest of the protective material ineffective.

[0037] 3. Ultrasonic Welding. This invention preferably uses ultrasonic welding instead of traditional heat sealing and pressing methods. It has two major advantages: First, it does not damage the protective layer. Due to the thicker intermediate layer, welding will not cause the fabric to burn through. There will be no needle holes, and no serious powder or air leakage. Furthermore, while ensuring the initial separation and flow channel, it also adds a subsequent spreading function, allowing the advantages of the resin powder to be fully utilized through the re-separation of the weld points. Second, it eliminates the need for glue. Due to the use of ultrasonic spot welding technology, this invention does not require glue between the outer and inner layers, greatly simplifying the process and avoiding interference from the glue layer on the physical state of the highly absorbent resin powder. This allows the powder to better absorb the injected water and expand more smoothly to fill the space between the outer and inner layers. When pressing the inner and outer layers together, there is no need for high-temperature pressing conditions, and excess glue will not melt due to heat, thus preventing the resin powder from absorbing the injected water at a slower rate.

[0038] 4. The outer layer is highly permeable, while the inner layer prevents powder leakage. Since the protective fabric of this invention must be infused with water before use, the outer layer must be highly permeable, ideally allowing water to penetrate within seconds. To this end, we have utilized ultrasonic welding points to create drainage channels, accelerating water infiltration. Furthermore, the inner layer uses a waterproof material, effectively preventing water and impurities from flowing into the inner layer and causing discomfort upon skin contact after the protective clothing is infused with water. Attached Figure Description

[0039] Figure 1 This is a cross-sectional structural diagram of an embodiment of the present invention;

[0040] Figure 2 This is a three-dimensional structural schematic diagram of an embodiment of the present invention;

[0041] Figure 3 This is a schematic diagram of the appearance of an embodiment of the present invention;

[0042] Figure 4 This is a schematic diagram of the appearance of an embodiment of the present invention;

[0043] Figure 5 This is a cross-sectional structural diagram of an embodiment of the present invention;

[0044] Figure 6 This is an enlarged schematic diagram of a three-dimensional mesh structure according to an embodiment of the present invention. Detailed Implementation

[0045] The embodiments of the present invention will be described in detail below. The following embodiments are implemented based on the technical solution of the present invention, and detailed implementation methods and specific operation processes are given. However, the protection scope of the present invention is not limited to the following embodiments.

[0046] refer to Figure 1-6This invention relates to the field of fire-fighting equipment technology and discloses a highly absorbent resin composite fabric, comprising an outer layer 1, an inner layer 2, and a middle layer 3. The middle layer 3 is characterized in that it is composed of a three-dimensional mesh structure 4, the three-dimensional mesh structure 4 including interconnected irregular mesh accommodating spaces 5, and highly absorbent resin powder 6 is accommodated in the accommodating spaces 5.

[0047] The composite fabric of this invention, due to the formation of a gel layer, possesses flame-retardant and heat-insulating functions, making it suitable for a wide range of applications. It can be made into heat-insulating clothing and blankets, or used to cover storage tanks or building surfaces for flame retardant and heat insulation, and can even be directly applied to extinguish fires. It can be used for fire emergency applications as well as in workplaces requiring daily heat insulation. The fabric of this invention uses highly absorbent resin powder 6 contained within a three-dimensional mesh fiber structure as the core heat-insulating material. Before use, it is mixed with water. Water can be sprayed onto the fabric, or the heat-insulating blankets or protective clothing made from the fabric can be immersed in water until the resin powder in the containment space 5 absorbs sufficient water, forming an airtight gel layer. Before use, it should be ensured that the highly absorbent resin powder forms a cohesive gel layer after absorbing water, avoiding situations where some parts absorb sufficient water while others do not. Superabsorbent resin powder itself is not fireproof or heat-insulating. All the heat insulation function comes from the gel layer formed after absorbing water and expanding. Therefore, these gels must cover the entire area that needs heat insulation, and there is no air between the gels.

[0048] In existing technologies, many protective suits are designed with a fire-resistant outer layer. This design effectively prevents the outer layer of the protective suit from burning in a short time. However, these products are generally made of thick and heavy materials and do not consider the water absorption of the middle layer of the protective suit. The water absorption rate is severely affected, and it cannot meet the requirements of the heat insulation fabric to absorb a large amount of water in a short time. At the same time, the cooperation between the outer layer and the middle layer is not fully reflected. In the event of a fire, they still act independently. In addition, the high cost and difficult processing of the fabric lead to many difficulties in practical application. In this invention, due to the presence of the three-dimensional mesh structure 4 of the middle layer 3, an interconnected irregular mesh-like accommodating space 5 is formed, in which the highly absorbent resin powder 6 is accommodated. The accommodating space 5 stores a large amount of highly absorbent resin powder. Once it absorbs water, it forms a continuous and dense heat insulation layer. According to experiments, it can directly block high temperatures of 500-800 degrees Celsius from the outer layer of the heat insulation fabric, so that the temperature of the inner layer of the heat insulation material is only about 50 degrees Celsius, and the heat insulation effect is very obvious. Furthermore, because the mesh structure of the intermediate layer firmly fixes the water-absorbing gel layer to the insulation fabric, the insulation fabric of this invention is no longer afraid of the surface of the fabric burning. According to experimental verification, after the surface fabric burns, some places will be burned through, and some places will be burned down to the residual carbon mesh material formed by the carbonization of the fabric. However, no matter what the surface layer becomes, the integrity of the gel layer in the intermediate layer 3 is well preserved. Therefore, the flame-retardant and heat-insulating performance can continue to play a role. Among them, the three-dimensional mesh structure 4 with a certain pore size of the intermediate layer 3 plays a key role. This spatial mesh structure has a certain strength. Before use, it can fix the highly absorbent resin powder 6 through the gaps. After absorbing water, it can fix the gel-like substance formed by the resin powder after absorbing water, so that the gel layer always protects people or objects inside the insulation fabric. It has been proven that sodium polyacrylate resin powder can be flame-retardant, heat-insulating and fire-extinguishing after absorbing water, but it has not been able to make a breakthrough in the field of insulation fabric for a long time. This is mainly due to the inability to fix the gel under high temperature and open flame conditions, which leads to gel detachment. Especially in emergency firefighting operations, when firefighters wear similar heat-insulating suits, they need to operate other firefighting equipment and move over large areas. Therefore, the continuous heat insulation capability of the fabric is crucial; the gel layer cannot be allowed to crack and peel off due to a few simple movements. This invention precisely meets these requirements, offering excellent resistance to high-temperature burns.

[0049] Furthermore, the outer layer 1 is made of hydrophilic nonwoven fabric with a pore size greater than 120 mesh, while the inner layer 2 is made of waterproof nonwoven fabric. In situations where fires are urgent, the outer layer 1 is designed for rapid water absorption, effectively facilitating the process from sprinkling or soaking water to absorption. Polyester fiber fabrics are often not permeable or hydrophilic, and some nonwoven materials are even waterproof, which poses significant challenges for absorbent fabrics. Therefore, the outer layer of the fabric must be designed as a hydrophilic layer. In addition, this invention uses a waterproof inner layer 2, which effectively prevents moisture and powder from directly contacting the skin. This ensures that absorbed moisture is largely contained within the middle layer 3 and prevents powder particles from accidentally penetrating the inner fabric and contacting the body. Specifying the pore size of the outer nonwoven fabric also prevents the resin powder 6 from escaping backwards.

[0050] Furthermore, the particle size of the superabsorbent resin powder 6, which accounts for more than 90% of the total weight of the superabsorbent resin powder 6, is controlled between 70-120 mesh, and the pore size of the three-dimensional network structure 4 is basically consistent with the controlled size of the superabsorbent resin powder 6 particles. We found that although the size of the resin particles is not limited, and they can still perform basic heat insulation and flame retardant functions after absorbing water, the gel layer formed after the resin absorbs water will still fall off or burn through relatively quickly after a period of time after being directly burned by an open flame. Through experimental analysis, we believe that this is likely due to the different sizes of the resin particles forming the gel layer. In particular, the larger resin powder particles, after absorbing water, do not have strong adhesion to the gel layer formed with other smaller resin powder particles. This weak adhesion is more obvious when the particle sizes differ greatly. Therefore, we designed the resin particle size variation range to be narrowed and the average particle size to be slightly smaller. This results in stronger adhesion between the gel particles after water absorption, better penetration of the inner and outer layers, and the formation of a denser, heat-insulating, and fire-resistant gel layer. Furthermore, the bond with the three-dimensional mesh structure 4 is stronger and less prone to detachment, making the insulation layer less susceptible to burn-through even under direct open flame. The table below shows a set of data from our actual measurements, illustrating that the sieved resin powder, after water absorption, exhibits superior fire-resistant and heat-insulating performance.

[0051] The sample is a double-sided non-woven fabric, with a fabric size of 30cm x 18cm.

[0052] Resin particle size No screening 20-80 mesh 70-120 mesh 90-100 mesh Water absorption time (seconds) 60 60 60 60 Flame temperature (°C) 1000 1000 1000 1000 Burn-through time (seconds) 29 30 35 38

[0053] In addition, refer to Figure 6Since the three-dimensional mesh structure 4 needs to hold and fix all the highly absorbent resin powder 6, its pore size should be adapted to the particle size of the powder 10. That is, most of the mesh pores formed after processing should be suitable for accommodating resin powder with a particle size of 70-120 mesh. The pores should not be too small or too large, otherwise the resin powder may not be able to enter the accommodating space or be properly fixed. Because the pore size of the three-dimensional mesh structure layer 8 is not completely uniform, in some embodiments, we can set more than 90% of the pore size of the three-dimensional mesh structure to be between 70-120 mesh. As for whether there are more large or small pores within the 70-120 mesh range, this is mainly determined roughly based on the sieve size, aiming to adapt to the size of most resin powder particles. The size of the superabsorbent resin powder particles needs to be controlled within a certain range. These size-compliant particles can be well fixed within the accommodating space 5 of the three-dimensional mesh structure 4. Particles that are too small can easily move irregularly between the mesh gaps, resulting in uneven powder distribution. Furthermore, fine particles can easily penetrate the gaps between the inner and outer non-woven fabric layers, causing powder leakage. Particles that are too large are difficult to fix within the mesh and will remain directly on the surface of the middle layer 3 without entering the accommodating space of the three-dimensional mesh structure 4. Simultaneously, particles of the predetermined size have excellent water absorption performance, maintain good spacing within the mesh, form a gel layer quickly, and have a uniform thickness and distribution. Even after the outer fabric is burned, the absorbent particles are less likely to fall off.

[0054] We found that although using large-sized resin particles does provide some insulation and flame retardancy after the fabric absorbs water, the low permeability of the resin powder particles into the intermediate layer 3 causes a large number of powder particles to float on top, resulting in weak welds and damage to the surface of the non-woven fabric after the inner and outer layers are bonded together. However, with the spatial mesh structure 4, all the powder particles meeting the required size enter the interior of the intermediate layer 3, preventing stress concentration-induced damage, and the distribution along the fabric's height is more rational. Smaller powder particles are distributed closer to the inner layer 2, while larger powder particles are distributed closer to the outer layer 1. Thus, during water absorption, the larger particles in the outer layer absorb water first. Because these large particles do not have a large actual surface area, their absorption rate is not very fast, and they do not expand rapidly in the initial stage of absorption, failing to form a dense gel layer that blocks water penetration. Therefore, the smaller particles in the inner layer can also fully absorb water, eventually bonding together to form a dense, airtight gel layer, providing excellent flame retardancy and insulation.

[0055] Furthermore, the strength of the three-dimensional mesh structure 4 of the intermediate layer 3 is configured to ensure that the three-dimensional mesh structure 4, after being bonded with the outer layer 1 and the inner layer 2, still has a thickness of at least 3 mm. There are various possibilities for the material selection of the intermediate layer 3, such as using commercially available nonwoven fabric that meets the requirements. In production practice, nonwoven fabric manufacturers will provide products that meet various parameters and specifications, and can also adjust the formula and process conditions according to customer requirements and needs. These are all conventional practices in this field. This method of manufacturing the nonwoven intermediate layer is not the focus of this invention. The specific form of the three-dimensional mesh structure is varied, but the inclusion of interconnected irregular mesh accommodating spaces 5 in the three-dimensional mesh structure 4 is a necessary condition. See [link to documentation]. Figure 6 First, the fibers must be connected to form a network; second, the network structure must have interconnected accommodating spaces 5. Only when these two conditions are met can the powder 6 be better inserted and fixed in the appropriate position, preventing powder and gel loss before and during use. Furthermore, it is crucial that the three-dimensional network structure 4 possesses sufficient strength and maintains a certain thickness during the lamination of the inner and outer layers. It must also maintain its overall network shape essentially unchanged after the resin powder expands upon contact with water. This ensures that the gel layer of a certain thickness is firmly fixed within the three-dimensional network structure, preventing the mesh from breaking and causing gel detachment when directly exposed to flame.

[0056] Further reference Figure 3-5 The outer layer 1, inner layer 2, and middle layer 3 are connected together by ultrasonic welding points 7. Compared with most existing adhesive bonding methods, this reduces unnecessary steps, improves bonding cleanliness, eliminates the interference of the adhesive layer on the water absorption and retention of the resin powder, and can combine the three-layer fabric structure together with appropriate bonding strength.

[0057] Further reference Figure 3-5 The ultrasonic welding points 7 divide the heat insulation fabric into several relatively separated independent parts 8. Although we have carried out various technical treatments, relative movement is unavoidable due to the physical properties of the powder particles and the three layers of fabric. In order to minimize the harm caused by this relative movement, we used ultrasonic welding points 7 to replace part of the function of the sewing thread, dividing the entire fabric into several independent parts, which better maintains the integrity and support strength of the middle layer. After the resin powder absorbs water and expands, it can fully exert all its functions and form a complete and uniform gel heat insulation layer.

[0058] Further reference Figure 3-5 The outer layer 1 has a flow guide groove 9, which is formed by ultrasonic welding points 7. In the design, we aim for a high water absorption and permeability rate for the outer layer 1, so the flow guide groove 9 is added; its shape can be arc-shaped or straight. Alternatively, the flow guide groove 9 can also function as a stitching line, reducing the need for additional ultrasonic welding points 7.

[0059] Furthermore, the welding adhesion strength of the ultrasonic weld point 7 is set such that the ultrasonic weld point 7 is stretched open after the highly absorbent resin powder 6 absorbs water. Because this invention incorporates an intermediate layer between the inner and outer surfaces, the ultrasonic intensity can be appropriately selected during ultrasonic welding to avoid damaging the inner and outer surfaces, resulting in a good bonding effect. In addition, since the bonding strength is not set very high, the movement of powder particles can be well controlled in the unabsorbed state; however, after reaching the minimum water absorption required for flame retardancy and heat insulation, the continuous expansion of the resin powder volume can stretch the ultrasonic weld point, effectively releasing the compressed three-dimensional spatial network structure. Thus, all the gel formed after water absorption can break through the limitations of the ultrasonic weld point dividing lines and bond together to form an integral gel layer, reinforcing the heat insulation layer around the weld point and achieving a superior protective effect.

[0060] Furthermore, the superabsorbent resin is a sodium polyacrylate copolymer. Our company's tests have shown that not all superabsorbent resin powders achieve optimal fire extinguishing effects. The water absorption, mixing, and state transition effects of various superabsorbent resin powders differ significantly, resulting in varying fire extinguishing effects when sprayed onto the ignition point after absorbing water. The water absorption rate, water absorption ratio, viscosity, and density of the sodium polyacrylate copolymer powder are highly compatible with the fire protection system and mixing method of this invention, achieving excellent fire extinguishing results.

[0061] Furthermore, this invention also discloses a method for manufacturing a highly absorbent resin composite fabric, used to manufacture the composite fabric as described above, comprising the following steps:

[0062] a) Control the size of more than 90% of the superabsorbent resin powder particles to be used to between 70-120 mesh;

[0063] b) The intermediate layer 3 is processed so that the three-dimensional mesh structure 4 of the intermediate layer 3 includes interconnected irregular mesh accommodating spaces 5, and the pore size of the three-dimensional mesh structure 4 is controlled to be basically consistent with the size of the superabsorbent resin powder 6 particles.

[0064] c) Temporarily fix the intermediate layer 3 to the inner layer 2;

[0065] d) Add highly absorbent resin powder 6 with a specified particle size to the intermediate layer 3, and stop adding the powder when the predetermined amount is reached;

[0066] e) During the feeding process, the inner layer 2 is horizontally vibrated to allow the powder to fully enter the irregular mesh-like accommodating space 5 of the three-dimensional mesh structure 4.

[0067] f) Cover the outer surface of the middle layer 3 with the outer layer 1;

[0068] g) The three-layer fabric structure is fixedly connected together by ultrasonic welding.

[0069] In this process, after initially screening the powder particles to obtain particles of a certain size, a suitable material needs to be selected to make the intermediate layer 3. If it does not meet our requirements for web formation and containment space, the raw materials need to be processed to obtain a structure that can perform the specified function. In practice, perforation or needle punching equipment can be used to process the intermediate layer 3, or a non-woven fabric web formation process can be directly adopted, or additional processing steps can be added to the manufacturing process to optimize the pore size of the intermediate layer 3. During the manufacturing process, in order to ensure that all the superabsorbent resin powder 6 is placed in the appropriate position and fills the web space, it is preferable to use additional vibration equipment to moderately intervene in the filling process, so that more powder particles enter the web space, forming a reasonable distribution of powder particles in height, and the spacing between them is small enough to form a complete, dense, airtight gel insulation layer.

[0070] Furthermore, after step d, the outer surface of the intermediate layer 3 is subjected to hot air treatment, causing the mesh structure of the three-dimensional mesh structure 4 to shrink and the surface pores to become smaller, thus fixing the powder 6 relatively within the accommodating space 5. To better fix the powder particles in the intermediate layer mesh structure 4, an additional hot air treatment step is used. After a predetermined amount of powder 6 has entered the accommodating space 5, the entire intermediate layer 3 is heated, causing a temperature rise, which in turn induces deformation and shrinkage of the fiber filaments. Since the internal mesh structure is inherently irregular, the hot air treatment does not substantially affect the irregular internal mesh structure of the intermediate layer 3. However, it causes the mesh structure to shrink towards the center, reducing the pore size on the outer surface, thereby tightly holding the resin powder particles and forming a more robust mesh structure. This strengthens the fixing effect of the intermediate layer 3 on the powder 6, preventing it from falling off during subsequent combustion.

[0071] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A highly absorbent resin composite fabric, comprising an outer layer (1), an inner layer (2), and a middle layer (3), characterized in that, The intermediate layer (3) is composed of a three-dimensional mesh structure (4), which includes interconnected irregular mesh accommodating spaces (5), and highly absorbent resin powder (6) is contained in the accommodating spaces (5); the outer layer (1) is made of hydrophilic non-woven fabric. The size of the superabsorbent resin powder (6) particles, which account for more than 90% of the total weight of the superabsorbent resin powder (6), is controlled between 70 and 120 mesh. The pore size of the three-dimensional mesh structure (4) is controlled to be basically consistent with the size of the superabsorbent resin powder (6) particles. After absorbing water, the superabsorbent resin powder (6) produces a gel-like substance and is fixed in the accommodating space of the three-dimensional mesh structure (4).

2. The composite fabric according to claim 1, characterized in that, The strength of the three-dimensional mesh structure (4) of the intermediate layer (3) is configured to ensure that the three-dimensional mesh structure (4) has a thickness of at least 3 mm after being joined with the outer layer (1) and the inner layer (2).

3. The composite fabric according to claim 1, characterized in that, The outer layer (1), inner layer (2) and intermediate layer (3) are connected together by ultrasonic welding points (7).

4. The composite fabric according to claim 3, characterized in that, The ultrasonic welding point (7) divides the heat insulation fabric into several relatively separated independent parts (8); the outer layer (1) has a flow channel (9), which is formed by the ultrasonic welding point (7).

5. The composite fabric according to claim 3, characterized in that, The welding adhesion strength of the ultrasonic weld point (7) is set such that the ultrasonic weld point (7) is stretched open after the superabsorbent resin powder (6) absorbs water.

6. The composite fabric according to claim 1, characterized in that, The outer layer (1) is made of hydrophilic nonwoven fabric with a pore size greater than 120 mesh, and the inner layer (2) is made of water-resistant nonwoven fabric.

7. The composite fabric according to claim 1, characterized in that, The superabsorbent resin is a sodium polyacrylate copolymer.

8. A method for manufacturing a highly absorbent resin composite fabric, characterized in that, The method for manufacturing the composite fabric as described in any one of claims 1-7 comprises the following steps: (a) The size of more than 90% of the superabsorbent resin powder (6) to be used is controlled between 70-120 mesh; (b) The intermediate layer (3) is processed so that the three-dimensional mesh structure (4) of the intermediate layer (3) includes interconnected irregular mesh accommodating spaces (5), and the pore size of the three-dimensional mesh structure (4) is controlled to be basically consistent with the size of the superabsorbent resin powder (6) particles. (c) Temporarily fix the intermediate layer (3) to the inner layer (2); (d) Add superabsorbent resin powder (6) with a specified particle size to the intermediate layer (3), and stop adding the powder when the predetermined amount is reached; (e) During the feeding process, the inner layer (2) is horizontally vibrated so that the powder can fully enter the irregular mesh accommodating space (5) of the three-dimensional mesh structure (4) that is interconnected; (f) Cover the outer layer (1) on the outer surface of the middle layer (3); (g) The three-layer fabric structure is fixedly connected together by ultrasonic welding.

9. The method for manufacturing composite fabric according to claim 8, characterized in that, After step (d), the outer surface of the intermediate layer (3) is subjected to hot air treatment, which causes the mesh structure of the three-dimensional mesh structure (4) to shrink and the surface pores to become smaller, thereby fixing the powder (6) relatively in the shrinking and deformed accommodating space (5).

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