A fiber material reinforcing method giving consideration to high tearability and high air permeability

Abstract

The application relates to the technical field of fiber materials, and provides a fiber material reinforcing method considering high tearability and high air permeability. The reinforcing method comprises the following steps: mixing and treating main body web forming fibers, high-strength low-shrinkage fibers, heat-shrinkable fibers and low-melting-point bonding components to obtain a mixed fiber material; performing forming treatment on the mixed fiber material to obtain a preformed fiber web; performing segmented heat treatment on the preformed fiber web, and performing selective heat stabilization treatment on the low-melting-point bonding components to obtain a fiber material. According to the application, the high-strength low-shrinkage fibers, the heat-shrinkable fibers and the low-melting-point bonding components are introduced into the base pore network formed by the main body web forming fibers, and the segmented heat treatment and the selective heat stabilization treatment are combined, so that the fiber network is subjected to controlled reconstruction under the action of heat, and heat-stable nodes are formed at local key connection positions, the internal through-pore structure of the fiber material is maintained, and the tear resistance and the structural stability of the fiber network are improved.

Description

Technical Field

[0001] This invention relates to the field of fiber materials technology, and more specifically, to a method for reinforcing fiber materials that balances high tear resistance and high air permeability. Background Technology

[0002] Existing fiber reinforcement methods often present a significant contradiction: on the one hand, to improve tear strength, it is often necessary to increase the inter-fiber bonding strength or improve structural density; on the other hand, densification and overall bonding compress pore channels, leading to decreased air permeability. Especially in paper-based materials, nonwoven materials, filter materials, and functional substrates, tear strength and air permeability are often difficult to balance.

[0003] In existing technologies, simply adding high-strength fibers, increasing pressing strength, increasing adhesive usage, or using overall hot pressing can usually only improve a single property and can easily cause pore blockage, material hardening, decreased hand feel, or poor processing adaptability.

[0004] Therefore, there is an urgent need for a fiber material reinforcement method that balances high tear resistance and high air permeability. Summary of the Invention

[0005] This invention aims to provide a fiber material reinforcement method that balances high tear strength and high air permeability. Through the synergistic effect of the skeleton reinforcement of high-strength, low-shrinkage fibers, the controlled shrinkage reconstruction effect of heat-shrinkable fibers, and the local thermal stabilization effect of low-melting-point binder components, the fiber network can obtain a more stable connection relationship without significantly destroying the through-pore structure, thereby balancing the high tear strength and high air permeability of the fiber material.

[0006] To address the above problems, this invention provides a method for reinforcing fiber materials that balances high tear resistance and high air permeability, comprising the following steps: S100. Mix the main web-forming fibers, high-strength low-shrinkage fibers, heat-shrinkage fibers and low-melting-point binder components to obtain a mixed fiber material. S200. The mixed fiber material is shaped to obtain a prefabricated fiber web; S300: The prefabricated fiber web is subjected to segmented heat treatment, and the low-melting-point binder component is subjected to selective heat stabilization treatment to obtain the fiber material.

[0007] In the above technical solution, in S100, the main web-forming fiber includes at least one of cellulose fiber, polyester fiber, polypropylene fiber, and viscose fiber; the high-strength low-shrinkage fiber includes at least one of aramid fiber, basalt fiber, glass fiber, and high-strength polyester fiber; the heat-shrinkable fiber includes at least one of heat-shrinkable polyester fiber, heat-shrinkable polypropylene fiber, and heat-shrinkable bicomponent fiber; and the low-melting-point bonding component includes at least one of low-melting-point polyester fiber, core-sheath type hot melt fiber, and low-melting-point copolyester fiber.

[0008] In the above technical solution, in S100, by mass percentage, the mixed fiber material includes: 1~20% high-strength low-shrinkage fiber, 1~15% heat-shrinkable fiber, 1~10% low-melting-point bonding component, and the remainder being the main web-forming fiber.

[0009] In the above technical solution, in S100, the mixing process includes at least one of opening mixing, dispersion mixing, and slurry mixing.

[0010] In the above technical solution, in S200, the forming process includes at least one of wet forming and airflow forming.

[0011] In the above technical solution, in S300, the segmented heat treatment includes a first heat treatment segment and a second heat treatment segment, and the temperature of the first heat treatment segment is lower than the temperature of the second heat treatment segment.

[0012] In the above technical solution, the temperature of the first heat treatment section is 80~140℃; the temperature of the second heat treatment section is 120~180℃.

[0013] In the above technical solution, in S300, selective thermal stabilization treatment includes low-pressure, short-time thermal setting or local thermal bonding methods.

[0014] In the above technical solution, the pressure for low-pressure, short-time heat setting is 0.02~0.30MPa, and the time is 5~300s.

[0015] In the above technical solutions, the local thermal bonding method includes at least one of point hot pressing, local hot rolling pressing, and local pulse heat sealing.

[0016] Beneficial effects (1) This invention introduces high-strength low-shrinkage fibers, heat-shrinkage fibers and low-melting-point bonding components into the basic porous network formed by the main web fibers, and combines segmented heat treatment and selective heat stabilization treatment to make the fiber network undergo controlled reorganization first and then form local stable nodes. This can enhance the connection between fibers and the load transfer path without relying on overall compaction or full-surface heat melting, thereby improving the tear resistance of the material. At the same time, it retains more through-pore structures, achieving a balance between high tear resistance and high air permeability. (2) In this invention, the heat-shrinkable fiber undergoes controlled shrinkage in the first heat treatment section, which can drive the surrounding fibers to re-approach, entangle and adjust the distribution state, so that the originally relatively loose prefabricated fiber network is transformed into a network structure with more reasonable connection and more continuous force path; the low melting point bonding component softens or melts at the fiber intersection or local area in the second heat treatment section and forms a heat-bonded node, thereby locally locking the reconstructed network structure. Detailed Implementation

[0017] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, a detailed description of specific embodiments of the present invention will be provided below.

[0018] Unless otherwise specified, all reagents and raw materials used in this invention are commercially available. Experimental methods in the following examples that do not specify particular conditions should be performed according to conventional methods and conditions, or as selected in the product instructions.

[0019] This invention provides a method for reinforcing fiber materials that balances high tear strength and high air permeability, addressing the problem of low tear strength and easy crack propagation due to insufficient fiber network connectivity while maintaining high air permeability. The reinforcement method of this invention includes the following steps: S100. Mix the main web-forming fibers, high-strength low-shrinkage fibers, heat-shrinkage fibers and low-melting-point binder components to obtain a mixed fiber material. S200. The mixed fiber material is shaped to obtain a prefabricated fiber web; S300: The prefabricated fiber web is subjected to segmented heat treatment, and the low-melting-point binder component is subjected to selective heat stabilization treatment to obtain the fiber material.

[0020] In S100, the main web-forming fibers, high-strength low-shrinkage fibers, heat-shrinkable fibers, and low-melting-point binder components are mixed to construct an initial fiber system with functional division of labor, providing a foundation for network reconstruction and node stabilization during subsequent forming and heat treatment processes. Specifically, the main web-forming fibers form a continuous basic web structure and initial pore channels; the high-strength low-shrinkage fibers are dispersed and embedded in the basic web structure to provide a reinforcing skeleton and bridging support during subsequent stress processes; the heat-shrinkable fibers undergo controlled shrinkage during subsequent heat treatment, causing surrounding fibers to re-adhere and promoting structural reorganization of the fiber network; and the low-melting-point binder components soften or melt in localized areas under subsequent thermal action, forming thermally stabilized nodes to locally lock the reconstructed fiber network.

[0021] Preferably, the main web-forming fiber includes at least one of cellulose fiber, polyester fiber, polypropylene fiber, and viscose fiber. These fibers possess good web-forming and pore-building capabilities, enabling the formation of a continuous fiber network. The high-strength, low-shrinkage fiber includes at least one of aramid fiber, basalt fiber, glass fiber, and high-strength polyester fiber. These fibers exhibit high strength, high modulus, and low heat shrinkage, serving as a relatively stable reinforcing skeleton during subsequent heat treatment and stress. The heat-shrinkable fiber includes at least one of heat-shrinkable polyester fiber, heat-shrinkable polypropylene fiber, and heat-shrinkable bicomponent fiber. These fibers can undergo controlled shrinkage upon heating, thereby applying an internal restructuring driving force to the fiber network. The low-melting-point bonding component includes at least one of low-melting-point polyester fiber, core-sheath type hot-melt fiber, and low-melting-point copolyester fiber. This component preferentially softens or melts under subsequent heat treatment conditions, forming a thermally bonded connection at the fiber contact points.

[0022] Furthermore, by mass percentage, the mixed fiber material comprises 1-20% high-strength, low-shrinkage fibers, 1-15% heat-shrinkable fibers, 1-10% low-melting-point binder components, with the remainder being the main web-forming fibers. Adopting the above proportions helps to achieve a balance between web formation, structural reinforcement, thermal remodeling, and local thermal stabilization. If the content of high-strength, low-shrinkage fibers is too low, the reinforcing effect on the skeleton is not significant; if the content is too high, it easily affects continuous web formation and processing uniformity. If the content of heat-shrinkable fibers is too low, the thermal remodeling effect is insufficient; if the content is too high, it easily causes excessive local shrinkage. If the content of low-melting-point binder components is too low, the thermally stabilized nodes are insufficient; if the content is too high, it easily increases the tendency for local densification.

[0023] Furthermore, the mixing process includes at least one of opening mixing, dispersion mixing, and sizing mixing to ensure that different fiber components are distributed as evenly as possible within the same system, avoiding agglomeration, local enrichment, or local absence. Preferably, when using wet forming, the mixing process includes dispersion and sizing of the fiber components to form a stable and uniform suspension system; when using air-flow forming, the mixing process includes opening and homogenizing mixing of the fiber components to improve the uniformity of the distribution of each component before dry web laying.

[0024] In S200, the mixed fiber material is shaped to obtain a prefabricated fiber web. This shaping process transforms various functional fibers from a mixed state into a network with actual overlapping, connecting relationships, and initial pore channels, thus providing a foundation for subsequent structural remodeling and localized thermal stabilization. Simultaneously, the uniformity of fiber arrangement, thickness distribution, and initial pore morphology formed during the shaping stage directly affect the uniformity of thermal shrinkage reconstruction and the formation location of thermally bonded nodes during subsequent segmented heat treatment.

[0025] Preferably, the forming process includes at least one of wet forming and airflow forming. In wet forming, the liquid-phase dispersion medium allows the fibers of each component to suspend, migrate, and deposit in a relatively uniform state, which is beneficial for constructing a prefabricated fiber web with uniform distribution and continuous pores. During wet forming, various fibers can redistribute in the liquid medium and gradually form a wet fiber web through filtration, dehydration, or deposition, which is beneficial for obtaining a more uniform in-plane and thickness-direction structure, improving the consistency of the fiber network response during subsequent heat treatment. In airflow forming, after being opened and dispersed, the fibers of each component are deposited under the action of airflow, which is beneficial for forming a prefabricated fiber web with high bulk and many open pores, providing greater structural control space for subsequent internal reconstruction driven by heat-shrinkable fibers and local thermal stabilization of low-melting-point binder components.

[0026] Preferably, the prefabricated fiber mesh has a layered structure, including at least a surface layer and an inner layer; the surface layer has a higher content of high-strength, low-shrinkage fibers than the inner layer, while the inner layer has a higher content of heat-shrinkable fibers and low-melting-point binder components than the surface layer. This layered structure facilitates the division of labor among different functional components along the thickness direction. The higher content of high-strength, low-shrinkage fibers in the surface layer helps to construct a relatively stable reinforcing skeleton on and near the material surface. Since cracks often preferentially initiate or propagate in the surface or near-surface region, placing more high-strength, low-shrinkage fibers in the surface layer helps to form bridging and load-sharing effects in the early stages of crack propagation and helps maintain the integrity of the surface structure during heat treatment. On the other hand, the higher content of heat-shrinkable fibers and low-melting-point binder components in the inner layer helps to concentrate the thermal reconstruction and thermal stabilization effects mainly within the material. When heated, the heat-shrinkable fibers can cause the inner layer fibers to re-aggregate, entangle, and reorganize, while the low-melting-point binder components can soften or melt locally, forming a localized lock on the reconstructed internal network. Therefore, while enhancing the stability of the internal structure, it can reduce the excessive closure of the open pore structure on the surface, thus helping to maintain the continuity of the overall air permeability channel.

[0027] In S300, the prefabricated fiber web undergoes segmented heat treatment, and the low-melting-point binder component is selectively heat-stabilized. This utilizes the differences in thermal response behavior among the different fiber components to achieve phased and functional structural control of the prefabricated fiber web. Specifically, a lower temperature stage induces controlled shrinkage of the heat-shrinkable fibers, generating a shrinkage driving force within the fiber network. This causes surrounding fibers to re-aggregate, entangle, and re-adjust their distribution, resulting in structural reorganization of the previously relatively loose prefabricated fiber web. Subsequently, a higher temperature stage softens or melts the low-melting-point binder component at fiber intersections or localized areas, forming localized heat-bonded nodes that lock and stabilize the fiber network reorganized in the previous stage. This enhances the stability and tear resistance of the fiber network while preserving as much of the material's internal porous structure as possible.

[0028] Preferably, in S300, the segmented heat treatment includes a first heat treatment stage and a second heat treatment stage, with the temperature of the first heat treatment stage being lower than that of the second heat treatment stage. This segmented heat treatment method leverages the difference in thermal response thresholds between the heat-shrinkable fibers and the low-melting-point binder component, allowing network reconstruction and network locking to occur step-by-step, avoiding excessive superposition of the two effects at the same time and resulting in structural imbalance. If the treatment is performed all at a high temperature, the low-melting-point binder component may soften or melt before the heat-shrinkable fibers have fully exerted their reconstruction effect, causing the fiber network to fix prematurely and limiting the space for the heat-shrinkable fibers to restructure the network structure. Conversely, if only heat shrinkage is performed without subsequent thermal stabilization, the reconstructed network structure is difficult to maintain for a long time, and the contact relationship between fibers is prone to loosening during subsequent use or under stress.

[0029] It is understandable that the first heat treatment stage is used to shrink the heat-shrinkable fibers to restructure the prefabricated fiber network. Under the condition of not prematurely causing significant softening or melting of the low-melting-point binder components, the thermal response behavior of the heat-shrinkable fibers is preferentially activated, allowing them to exert an internal shrinkage driving force on the surrounding fiber network. This helps transform the fiber network from a relatively loose initial state with limited contact points into a restructured state with more sufficient fiber contact, more stable local entanglement, and a more continuous force path. Since this process mainly relies on the shrinkage behavior of the heat-shrinkable fibers themselves, rather than primarily on external mechanical compression, it can enhance network connectivity while reducing the risk of the overall pore structure being directly crushed. Simultaneously, the high-strength, low-shrinkage fibers, due to their smaller thermal dimensional changes at this stage, can act as a relatively stable reinforcing skeleton, providing a supporting boundary for the network reconstruction brought about by the heat-shrinkable fibers, making the network restructuring process more controlled and reducing local collapse or shrinkage imbalance.

[0030] It is understandable that the second heat treatment stage is used to soften or melt the low-melting-point binder components to thermally stabilize the prefabricated fiber web. The main function of the second heat treatment stage is not to drastically alter the network morphology, but rather to fix the optimized network structure formed in the first heat treatment stage through localized thermal bonding. By forming thermal bonding nodes at fiber intersections, contact areas, or localized regions, the fiber network structure reformed in the first heat treatment stage is less prone to springback and loosening, and it helps improve the bonding strength between fibers and the stability of the network structure. Since thermal bonding mainly occurs in the low-melting-point binder components, while the main web-forming fibers and high-strength, low-shrinkage fibers typically do not melt significantly in this temperature range, structural locking can be achieved under relatively mild conditions, preventing the entire fiber web from becoming a large-area fused state.

[0031] Furthermore, the temperature of the first heat treatment stage is 80~140℃, and the temperature of the second heat treatment stage is 120~180℃. When the temperature of the first heat treatment stage is controlled at 80~140℃, the heat-shrinkable fibers suitable for the system of this invention can undergo significant heat-induced shrinkage, thereby effectively reorganizing the fiber network. If the temperature is too low, the heat-shrinkable fibers shrink insufficiently, and the network reconstruction is not significant; if the temperature is too high, the low-melting-point bonding components may soften or even melt prematurely, causing the network to be fixed prematurely before it has been fully reconstructed. When the temperature of the second heat treatment stage is controlled at 120~180℃, the low-melting-point bonding components such as low-melting-point polyester fibers, core-sheath type hot-melt fibers, and low-melting-point copolyester fibers can soften or melt sufficiently, thereby forming stable local heat-bonded nodes. If the temperature is too low, the heat bonding is insufficient, and the network locking effect is limited; if the temperature is too high, it can easily lead to the expansion of the heat-bonded area, enhanced local melt collapse, and even damage to the pore structure formed by the main web-forming fibers.

[0032] Preferably, selective heat stabilization treatment includes low-pressure, short-time heat setting or localized heat bonding. The aim is to ensure that the low-melting-point binder primarily forms a heat-stabilizing effect in key bonding areas, avoiding prolonged, high-pressure, full-surface heat pressing of the entire fiber web. On the one hand, less external force and shorter treatment time can promote effective bonding of the low-melting-point binder in localized locations, thereby stabilizing the fiber network; on the other hand, it can reduce the overall compaction degree and continuous sealing tendency, minimizing damage to the through-pore structure.

[0033] Preferably, the segmented heat treatment is carried out under low tension or without external stretching constraints. These conditions allow the heat-shrinkable fibers to fully release their shrinkage tendency, thus maximizing their internal restructuring effect on the prefabricated fiber web. If heat treatment is performed under high tension or significant external stretching constraints, the shrinkage behavior of the heat-shrinkable fibers will be suppressed, and their traction, convergence, and reorganization effects on surrounding fibers will be difficult to fully manifest, thereby weakening the structural reorganization effect of the first heat treatment stage. Simultaneously, low tension or no external stretching constraints also helps reduce uneven deformation of the fiber web caused by external forces during heat treatment, making the heat shrinkage reconstruction process more uniform and contributing to maintaining the continuity and stability of the pore structure.

[0034] Preferably, the pressure for low-pressure, short-time heat setting is 0.02~0.30 MPa, and the time is 5~300 s. If the pressure is too low, there will be insufficient contact between fibers, and even if the low-melting-point binder softens, it will be difficult to form a stable and effective bond. If the pressure is too high, it will easily lead to overall flattening of the fiber web, increased pore compression, and even excessive expansion of local melt, forming dense areas that are not conducive to the retention of air permeability channels. If the time is too short, heat transfer will be insufficient, and the low-melting-point binder will not soften sufficiently, making it difficult to form a stable bond. If the time is too long, the accumulated heat effect may be too strong, leading to an expansion of the heat-bonded area or excessive overall thermal shrinkage, which is not conducive to maintaining the pore structure.

[0035] Preferably, the localized thermal bonding method includes at least one of point-type hot pressing, localized hot rolling, and localized pulse heat sealing. In these methods, heat and pressure are applied only to a portion of the fiber web, rather than providing continuous full-width coverage. This allows for the pre-setting or formation of discrete thermally stable regions within the fiber web, enabling the low-melting-point bonding component to form thermally bonded nodes only in the localized areas requiring reinforcement, thus achieving localized reinforcement and targeted locking of the structure. Point-type hot pressing is advantageous for forming discrete node-type connections; localized hot rolling is beneficial for achieving strip-like or intermittent thermal stabilization in continuous production; and localized pulse heat sealing is advantageous for forming rapid and controlled thermally bonded points through short-term localized high-heat input.

[0036] Furthermore, the localized thermal bonding method creates spaced thermally bonded areas within the prefabricated fiber web, where the low-melting-point bonding components are distributed. This spatially discontinuous layout allows thermally stabilized nodes to function as structural anchors, while the non-thermally bonded areas remain as primary pore channels. The thermally bonded areas act as localized reinforcing nodes, improving the fiber network's connection stability and stress transmission capacity; meanwhile, the unbonded areas between the thermally bonded regions maintain a high degree of fiber openness and pore connectivity, thus facilitating the continuous preservation of breathable channels. Compared to continuous planar thermally fused layers, this spaced-out thermally bonded area better reflects the synergistic balance between localized stability and overall breathability achieved in this invention. Example 1

[0037] This embodiment provides a method for reinforcing fiber materials that balances high tear resistance and high air permeability, including the following steps: S1. Dissolve 600g of bleached softwood pulp fiber in deionized water for 20min; then add 220g of polyester staple fiber, 80g of meta-aramid staple fiber, 50g of heat-shrinkable polyester staple fiber and 50g of core-sheath type hot melt fiber, and add AEO-9 equivalent to 0.05% of the fiber's oven-dry weight. Disperse and stir at 600rpm for 15min at room temperature to prepare a mixed fiber material with a solid content of 0.30wt%. S2. The mixed fiber material is wet-formed using an experimental circular screen forming device, and after vacuum dehydration, a wet pre-fabricated fiber web is obtained; then it is pre-dried under 90℃ hot air conditions to a moisture content of less than 10% to obtain a pre-fabricated fiber web; S3. The prefabricated fiber web is subjected to segmented heat treatment under low tension and no external stretching constraint: first, it is treated in a 110℃ hot air oven for 90s as the first heat treatment segment; then, it is heated to 150℃ for 45s as the second heat treatment segment; after the second heat treatment segment, it is immediately subjected to low-pressure, short-time heat setting in a 150℃ heat setting roller, with a pressure of 0.08MPa and a time of 30s, to obtain the fiber material. Example 2

[0038] This embodiment provides a method for reinforcing fiber materials that balances high tear resistance and high air permeability, including the following steps: S1. Prepare surface slurry and inner slurry separately, and control the solid content of the slurry to be 0.25wt%, and the dispersion time for both to be 15min; the surface slurry includes 220g of bleached softwood pulp fiber, 150g of viscose staple fiber and 120g of meta-aramid staple fiber; the inner slurry includes 220g of bleached softwood pulp fiber, 150g of viscose staple fiber, 80g of heat-shrinkable bicomponent fiber and 60g of low-melting-point copolyester fiber; S2. A layered wet forming process is adopted, first forming the first surface layer, then forming the inner layer, and finally forming the second surface layer; after vacuum dehydration and pre-drying at 90℃, a three-layer prefabricated fiber web is obtained. The surface slurry is used to form the first surface layer and the second surface layer, and the amount of slurry used in the first surface layer and the second surface layer is the same. The oven-dry mass ratio of the first surface layer, the inner layer and the second surface layer is 25:50:25. S3. Segmented heat treatment under low tension conditions: First heat treatment stage: 115℃ hot air treatment for 100s; Second heat treatment stage: 155℃ hot air treatment for 35s; Subsequently, selective heat stabilization treatment is carried out by dot-matrix hot pressing. The diameter of a single dot pattern on the surface of the hot press roller is 1.0mm, the dot spacing is 4.5mm, the hot pressing contact area accounts for about 12% of the total area, the hot pressing temperature is 155℃, the pressure is 0.15MPa, and the time is 20s to obtain the fiber material. Example 3

[0039] This embodiment provides a method for reinforcing fiber materials that balances high tear resistance and high air permeability, including the following steps: S1. 400g of viscose staple fiber, 400g of polypropylene staple fiber, 60g of basalt chopped fiber, 80g of heat-shrinkable polypropylene staple fiber and 60g of core-sheath type hot melt fiber are opened; after opening, they are homogenized and mixed in a mixing box for 10 minutes to obtain mixed fiber material. S2. The mixed fiber material is laid into a web using an airflow forming equipment to form a prefabricated fiber web under negative pressure adsorption conditions. S3. Segmented heat treatment is carried out without external stretching constraints: First heat treatment stage: 100℃ hot air treatment for 80s; Second heat treatment stage: 130℃ hot air treatment for 25s; Subsequently, selective heat stabilization treatment is carried out by local hot roller pressing. The surface of the hot roller has a striped intermittent pattern. The actual heat contact area accounts for about 18% of the total area. The hot roller temperature is 135℃, the pressure is 0.10MPa, and the contact time is about 15s to obtain the fiber material. Example 4

[0040] This embodiment provides a method for reinforcing fiber materials that balances high tear resistance and high air permeability, including the following steps: S1. Add 800g of bleached softwood pulp fiber, 170g of polyester staple fiber, 10g of meta-aramid staple fiber, 10g of heat-shrinkable bicomponent fiber and 10g of core-sheath type hot melt fiber to deionized water to prepare a mixed pulp with a solid content of 0.20wt%. Disperse and stir at 500rpm for 10min to obtain mixed fiber material. S2. The pre-woven fiber web is obtained by wet forming and pre-drying with hot air at 80℃ to a moisture content of 8%. S3. Perform segmented heat treatment under low tension conditions: the temperature of the first heat treatment section is 80℃, and the treatment time is 60s; the temperature of the second heat treatment section is 120℃, and the treatment time is 10s; then, selective heat stabilization treatment is carried out by low pressure and short time heat setting, with a pressure of 0.02MPa and a time of 5s, to obtain fiber material. Example 5

[0041] This embodiment provides a method for reinforcing fiber materials that balances high tear resistance and high air permeability, including the following steps: S1. 550g of polyester staple fiber, 200g of high-strength polyester staple fiber, 150g of heat-shrinkable polyester staple fiber and 100g of low-melting-point polyester fiber are opened and mechanically mixed in sequence for 12 minutes to obtain mixed fiber material. S2. The prefabricated fiber web is obtained by airflow forming. S3. Segmented heat treatment is carried out without external stretching constraints: the temperature of the first heat treatment segment is 140℃, and the treatment time is 45s; the temperature of the second heat treatment segment is 180℃, and the treatment time is 90s; then selective heat stabilization treatment is carried out by local pulse heat sealing. The width of the pulse heat sealing strip is 1.2mm, the center distance between adjacent heat sealing strips is 8mm, the pulse heat sealing pressure is 0.30MPa, and the total heat sealing time is 300s, to obtain the fiber material. Example 6

[0042] This embodiment provides a method for reinforcing fiber materials that balances high tear resistance and high air permeability, including the following steps: S1. After fully disintegrating 480g of bleached softwood pulp fiber, add 300g of polyester staple fiber, 100g of E-glass chopped fiber, 60g of heat-shrinkable bicomponent fiber and 60g of low-melting-point copolyester fiber in sequence to prepare a mixed fiber material with a solid content of 0.25wt%. S2. A pre-fabricated fiber web is obtained by wet forming; S3. Perform segmented heat treatment under low tension conditions: the first heat treatment stage is 105℃ for 80s; the second heat treatment stage is 150℃ for 30s; then, a low-pressure short-time heat setting method is adopted, with a pressure of 0.10MPa and a time of 20s, to obtain the fiber material.

[0043] Comparative Example 1 This comparative example provides a method for reinforcing fiber materials that balances high tear strength and high breathability. The preparation method is as shown in Example 1, except that in S1, 640g of bleached softwood pulp fiber, 260g of polyester staple fiber, 50g of heat-shrinkable polyester staple fiber and 50g of core-sheath type hot melt fiber are added, that is, high-strength low-shrinkage fiber is not added.

[0044] Comparative Example 2 This comparative example provides a method for reinforcing fiber materials that balances high tear strength and high breathability. The preparation method is as shown in Example 1, except that in S1, 630g of bleached softwood pulp fiber, 240g of polyester staple fiber, 80g of meta-aramid staple fiber and 50g of core-sheath type hot melt fiber are added, that is, no heat shrink fiber is added.

[0045] Comparative Example 3 This comparative example provides a method for reinforcing fiber materials that balances high tear resistance and high breathability. The preparation method is as shown in Example 1, except that in S1, 630g of bleached softwood pulp fiber, 240g of polyester staple fiber, 80g of meta-aramid staple fiber and 50g of heat-shrinkable polyester staple fiber are added, that is, no low-melting-point binder is added.

[0046] Comparative Example 4 This comparative example provides a method for reinforcing fiber materials that balances high tear strength and high air permeability. The preparation method is as shown in Example 1, except that in S3, the pre-made fiber web is directly and continuously treated at 150°C for 90 seconds, and then heat-set at 0.08MPa for 30 seconds. That is, instead of segmented heat treatment, a single-stage high-temperature treatment is used.

[0047] Comparative Example 5 This comparative example provides a method for reinforcing fiber materials that balances high tear strength and high air permeability. The preparation method is as shown in Example 1, except that in S3, hot pressing is performed using a whole-plane flat plate hot pressing method. The hot pressing temperature is 150°C, the pressure is 0.60MPa, and the time is 120s. That is, continuous hot pressing of the whole surface is used instead of selective heat stabilization treatment.

[0048] Performance testing Examples 1-6 and Comparative Examples 1-5 were tested using the following methods, and the test results are shown in Table 1. Quantitative testing: Performed according to GB / T 451.2; Thickness: Tested according to GB / T 451.3; Tear strength: Tested using the Elemendorf tear test; Breathability: Tested according to GB / T 5453; Table 1 As shown in Table 1, Examples 1-6 all achieved high tear strength while maintaining high air permeability. Comparative Example 1, without the addition of high-strength, low-shrinkage fibers, while maintaining high air permeability, showed a significant decrease in tear strength, indicating that high-strength, low-shrinkage fibers play a crucial role in improving load transfer and bridging during crack propagation. Comparative Example 2, without the addition of heat-shrinkable fibers, lacked the driving force for thermal reforming of the fiber network, resulting in insufficient optimization of fiber contact relationships and stress paths, leading to a lower tear strength than Example 1. Comparative Example 3, without the addition of low-melting-point binder components, although heat shrinkage reconstruction could still occur, the network lacked subsequent local locking, making it difficult to maintain stable connections after reconstruction, thus resulting in unsatisfactory tear strength. Comparative Example 4 used single-stage high-temperature treatment instead of segmented heat treatment, indicating that when network reconstruction and thermal stabilization occur simultaneously, the low-melting-point binder components may soften prematurely, limiting the full reforming effect of the heat-shrinkable fibers. Comparative Example 5 used continuous hot pressing across the entire surface, which improved tear strength to some extent, but significantly reduced air permeability, indicating that overall compaction and full-surface hot melting significantly damage the interconnected pore structure.

[0049] Any person skilled in the art can make various modifications and alterations without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope defined in the claims.

Claims

1. A method for reinforcing fiber materials that balances high tear resistance and high breathability, characterized in that, Includes the following steps: S100. Mix the main web-forming fibers, high-strength low-shrinkage fibers, heat-shrinkage fibers and low-melting-point binder components to obtain a mixed fiber material. S200: The mixed fiber material is shaped to obtain a prefabricated fiber web; S300. The prefabricated fiber web is subjected to segmented heat treatment, and the low-melting-point binder component is subjected to selective heat stabilization treatment to obtain the fiber material.

2. The enhancement method according to claim 1, characterized in that, In S100, the main web-forming fiber includes at least one of cellulose fiber, polyester fiber, polypropylene fiber, and viscose fiber; The high-strength, low-shrinkage fiber includes at least one of aramid fiber, basalt fiber, glass fiber, and high-strength polyester fiber. The heat-shrinkable fiber includes at least one of heat-shrinkable polyester fiber, heat-shrinkable polypropylene fiber, and heat-shrinkable bicomponent fiber. The low-melting-point binder component includes at least one of low-melting-point polyester fiber, core-sheath type hot melt fiber, and low-melting-point copolyester fiber.

3. The enhancement method according to any one of claims 1 or 2, characterized in that, In S100, by mass percentage, the mixed fiber material comprises: 1-20% of the high-strength, low-shrinkage fiber, 1-15% of the heat-shrinkable fiber, 1-10% of the low-melting-point binder component, and the balance being the main web-forming fiber.

4. The enhancement method according to claim 1, characterized in that, In S100, the mixing process includes at least one of opening mixing, dispersion mixing, and slurry mixing.

5. The enhancement method according to claim 1, characterized in that, In S200, the forming process includes at least one of wet forming and airflow forming.

6. The enhancement method according to claim 1, characterized in that, In S300, the segmented heat treatment includes a first heat treatment segment and a second heat treatment segment, and the temperature of the first heat treatment segment is lower than the temperature of the second heat treatment segment.

7. The enhancement method according to claim 6, characterized in that, The temperature of the first heat treatment section is 80~140℃; the temperature of the second heat treatment section is 120~180℃.

8. The enhancement method according to claim 1, characterized in that, In S300, the selective thermal stabilization process includes low-pressure, short-time thermal setting, or localized thermal bonding methods.

9. The enhancement method according to claim 8, characterized in that, The pressure for low-pressure, short-time heat setting is 0.02~0.30MPa, and the time is 5~300s.

10. The enhancement method according to claim 8, characterized in that, The localized thermal bonding method includes at least one of point hot pressing, localized hot rolling, and localized pulse heat sealing.

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