An enhanced ultra-thin natural fiber felt and a method for manufacturing the same

Abstract

The application relates to the technical field of non-woven materials, in particular to a reinforced ultra-thin natural fiber felt and a preparation method thereof, and the preparation method of the reinforced ultra-thin natural fiber felt comprises the following steps: S1, base material preparation: taking a porous reinforced base material and placing the base material on a web supporting curtain; S2, web laying: preparing a web from natural fibers, and then laying the web on the porous reinforced base material; S3, airflow pre-looping: forming a micro-loop structure of the natural fibers in the web on the porous reinforced base material by applying negative pressure suction airflow on the side of the web supporting curtain far from the web; S4, needle punching and compacting: preparing a crude product through needle punching; and S5, post-finishing: preparing the reinforced ultra-thin natural fiber felt after finishing; the reinforced ultra-thin natural fiber felt has the advantages of improving the lightness, strength and surface touch of the felt fabric.

Description

Technical Field

[0001] This application relates to the technical field of nonwoven materials, and in particular to an enhanced ultrathin natural fiber felt and its preparation method. Background Technology

[0002] Natural fibers, including wool, cashmere, rabbit hair, camel hair, and silk, possess excellent warmth retention, moisture absorption, elasticity, and biodegradability, making them widely used in clothing and home textiles. However, for felt products, such as wool felt, traditional manufacturing methods primarily involve needle punching or wet felting processes. This results in a felt surface composed of numerous free fiber ends, leading to pilling, a prickly feel, and reduced skin comfort. Furthermore, to ensure strength, felt is typically quite thick, limiting its application in lightweight and refined products; however, making it thinner results in insufficient strength, susceptibility to deformation, and breakage. Existing felt products also have relatively limited functionality, primarily focusing on warmth and decoration, making it difficult to meet the demands for composite functions such as high strength, high abrasion resistance, and high elastic recovery.

[0003] To address the aforementioned issues, some related technologies have attempted to incorporate reinforcing substrates into the felt or use chemical adhesives, but these often sacrifice the material's softness, breathability, and environmental friendliness. Another method is the napping needle punching process, which uses irregularly shaped needles such as forked needles to hook fibers onto the surface and form loops. However, this method causes significant damage to the fibers, and the resulting loops are highly random, making it difficult to achieve a uniform, smooth, and uniquely tactile surface. Therefore, developing a novel felt fabric that retains the excellent natural properties of natural fibers while also possessing characteristics such as ultra-thinness, high strength, and a superior surface feel is a pressing technical challenge in this field. Summary of the Invention

[0004] To improve the lightness, strength, and surface feel of felt fabrics, this application provides an enhanced ultrathin natural fiber felt and a method for preparing the same.

[0005] In a first aspect, this application provides a method for preparing reinforced ultrathin natural fiber felt, employing the following technical solution: A method for preparing reinforced ultrathin natural fiber felt, comprising the following steps: S1. Substrate Preparation Take a porous reinforced substrate and place it on the support net curtain; S2, Fiber mesh laying Natural fibers are prepared into a fiber web, and then the fiber web is laid flat on the porous reinforced substrate; S3, airflow pre-formed ring By applying negative pressure suction airflow to the side of the support curtain away from the fiber web, the natural fibers in the fiber web form a micro-ring structure on the porous reinforcing substrate; S4, Needle-based fixation A crude product is obtained by performing one and two acupuncture sessions, or by performing multiple acupuncture sessions after one acupuncture session, with the acupuncture density of the two sessions being greater than that of the one session. S5, Post-processing The coarse material is heat-set, sheared and / or brushed, and / or softened to produce reinforced ultra-thin natural fiber felt.

[0006] By adopting the above technical solution, this application successfully prepared a high-performance reinforced ultrathin fiber felt by introducing an "airflow pre-ringing" step and combining it with a porous reinforcing substrate and a refined needle punching process. Its anti-pilling and anti-fuzzing properties are significantly improved, and the feel evaluation jumps from "obvious prickliness" to "extreme smoothness." This airflow pre-ringing step plays a decisive role in improving the product's surface quality and feel. Airflow pre-ringing allows natural fibers to pass through the mesh of the porous reinforcing substrate, forming a micro-ring structure, which reduces damage to the natural fibers and preserves their excellent fiber properties. Subsequent low-density and high-density needle punching further increases the density and uniformity of the micro-ring structure of the natural fiber felt, and significantly reduces the number of fiber ends on the felt surface. This results in a natural fiber felt that simultaneously possesses the advantages of being ultrathin, lightweight, high-strength, and having a comfortable surface feel, making it highly valuable for market applications.

[0007] Preferably, the porous reinforcing substrate is a polymer fiber mesh, a metal wire mesh, or a natural fiber mesh.

[0008] By adopting the above technical solution, the porous reinforcing substrate is an essential condition for the preparation of natural fiber felt in this application. It can serve as the supporting skeleton of the felt, realize the high strength performance of the felt, and through the airflow pre-ringing step, the natural fibers can pass through its mesh, thus realizing the ultra-thin performance of the felt. Based on this function, the porous reinforcing substrate can be a polymer fiber mesh, a metal wire mesh, or a natural fiber mesh, all of which can produce natural fiber felt with excellent comprehensive performance.

[0009] Preferably, the polymer fiber web is a warp-knitted, weft-knitted, or nonwoven fabric made of one or more of polyamide fibers, polyester fibers, and polypropylene fibers.

[0010] Preferably, the porous reinforced substrate has a mesh size range of 0.5-5 mm.

[0011] By adopting the above technical solutions, the pore size of the porous reinforced substrate is also an important factor affecting product performance. If the pore size is too small or too large, it will not be conducive to the penetration and ring formation of natural fibers.

[0012] Preferably, the porous reinforcing substrate has a basis weight of 30-150 g / m², the fiber web has a basis weight of 80-200 g / m², and the natural fiber has a fineness of 14-24 μm.

[0013] By adopting the above technical solution, and by limiting the basis weight of the porous reinforced substrate, the basis weight of the fiber, and the fineness of the natural fiber, it is beneficial to control the final thickness, surface comfort, and strength of the natural fiber felt.

[0014] Preferably, in step S3, the negative pressure is 0.5-8 kPa, and the negative pressure is applied for 1-10 seconds.

[0015] By adopting the above technical solution, natural fibers can pass through the mesh of the porous reinforced substrate through negative pressure suction, forming a uniform micro-ring structure.

[0016] Preferably, the height of the micro-ring structure is 0.1-10 mm, and the distribution density is 50-500 rings / cm².

[0017] By adopting the above technical solutions, the height and distribution density of the micro-ring structure can be further limited, which can make the thickness of the felt uniform, reduce surface burrs, and enhance surface comfort.

[0018] Preferably, in step S4, the acupuncture density of the first acupuncture is 40-80 needles / cm², and the acupuncture density of the second acupuncture is 80-200 needles / cm².

[0019] By adopting the above technical solution, the density of the first needle punch is relatively low. Its purpose is to gently and initially physically entangle and lock the root of the micro-ring structure formed by the airflow in S3 with the substrate to complete the basic solidification, while avoiding the destruction of the already formed ring surface by subsequent high-density needle punching. The density of the second needle punch is relatively high. Its purpose is to finally determine the density, thickness and surface morphology of the fabric.

[0020] Preferably, the natural fiber is one or more of wool, cashmere, camel hair, and rabbit hair.

[0021] Secondly, this application provides an enhanced ultra-thin natural fiber felt, employing the following technical solution: An enhanced ultrathin natural fiber felt is prepared by the method for preparing the enhanced ultrathin natural fiber felt.

[0022] By adopting the above technical solution, the natural fiber felt prepared by the method in this application has a basis weight of about 180g / m², a thickness of less than 1mm, an air permeability of 1050-1250mm / s, a longitudinal breaking strength of 270N or more, with a maximum of 285N, a minimum coefficient of friction of 0.12, and other properties are also excellent. Its comprehensive performance is far superior to existing technology products, and it meets the market demand for lightweight, high strength and comfortable surface feel, and has extremely high market application value.

[0023] In summary, this application includes at least one of the following beneficial technical effects: 1. This application successfully prepared a high-performance reinforced ultrathin fiber felt by introducing an "airflow pre-ringing" step and combining it with a porous reinforcing substrate and a refined needle punching process. The felt exhibits significantly improved anti-pilling and anti-fuzzing properties, and its feel evaluation jumped from "noticeably prickly" to "extremely smooth." This airflow pre-ringing step plays a decisive role in improving the product's surface quality and tactile feel. Airflow pre-ringing allows natural fibers to pass through the mesh of the porous reinforcing substrate, forming a micro-ring structure. This reduces damage to the natural fibers and preserves their excellent fiber properties. Subsequent low-density and high-density needle punching further increases the density and uniformity of the micro-ring structure in the natural fiber felt, while significantly reducing the number of fiber ends on the felt surface. This results in a natural fiber felt that simultaneously possesses the advantages of being ultrathin, lightweight, high-strength, and having a comfortable surface feel, making it highly valuable for market applications.

[0024] 2. The natural fiber felt prepared in this application has a basis weight of about 180g / m², a thickness of less than 1mm, an air permeability of 1050-1250mm / s, a longitudinal tensile strength of 270N or more, with a maximum of 285N, a minimum coefficient of friction of 0.12, and other properties are also excellent. Its comprehensive performance is far superior to existing technology products, and it meets the market demand for lightweight, high strength and comfortable surface feel, and has extremely high market application value. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of the structure of an enhanced ultrathin natural fiber felt in Example 1.

[0026] Figure 2 This is a schematic diagram illustrating the micro-ring structure after secondary compaction in Example 1.

[0027] Figure 3 This is a micrograph of the surface of the finished natural fiber felt prepared in Example 1.

[0028] Figure 4This is a micrograph of the surface of the finished natural fiber felt prepared in Example 2.

[0029] Figure 5 This is a micrograph of the finished surface of the natural fiber felt prepared in Comparative Example 1.

[0030] Figure 6 This is a micrograph of the surface of the finished natural fiber felt prepared in Comparative Example 2.

[0031] Reference numerals: 1. Porous reinforced substrate; 11. Mesh; 2. Natural fiber; 3. Micro-ring structure. Detailed Implementation

[0032] The following provides a more detailed description of this application in conjunction with specific details.

[0033] raw material

[0034] All raw materials used in this application are common commercially available products. Example

[0035] Example 1 A reinforced ultrathin natural fiber felt is prepared as follows: S1. Substrate Preparation like Figure 1 As shown, the porous reinforcing substrate 1 with through-holes 11 is selected, which can be a polymer fiber mesh, a metal wire mesh, or a natural fiber mesh. The polymer fiber mesh can be a warp-knitted, weft-knitted, or non-woven mesh made of polyamide (nylon), polyester (polyester), polypropylene, etc.; in this embodiment, a basis weight of 60 g / m² is used. 2 Recycled nylon 66 elastic mesh with an average aperture of 2.5 mm was placed on a support curtain equipped with a suction fan. S2, Fiber mesh laying Natural fiber 2 is a natural protein fiber, which can be wool, cashmere, camel hair, rabbit hair, etc.; in this embodiment, Australian Merino wool is used, with an average fineness of 18.5μm and an average length of 8cm. It is formed into a uniform fiber web through opening and carding processes, and the unit area mass of the fiber web is 120g / m². 2 Then it is laid flat on the porous reinforced substrate 1 prepared in S1; S3, airflow pre-formed ring A pre-set pressure difference is established on the upper and lower sides of the porous reinforced substrate 1 and the fiber web by a suction fan, driving airflow to vertically penetrate the porous reinforced substrate 1 and the fiber web in a short time. The force of the airflow causes the natural fibers 2 in the fiber web layer adjacent to the substrate to partially and non-destructively pass through the mesh 11 of the substrate along the airflow direction; such as Figure 1As shown, a raised, complete, non-end-exposed micro-ring structure 3 is formed on the other side surface of the porous reinforced substrate 1. The micro-ring structure 3 is densely and uniformly distributed, and its root is physically anchored by the mesh 11 of the porous reinforced substrate 1. The specific operation is as follows: Start the fan below the mesh curtain, apply a negative pressure suction airflow of 2.5 kPa for 3 seconds, so that the wool fibers in the mesh form a uniform micro-ring structure 3 on the porous reinforcing substrate 1. The average height of the micro-ring structure 3 is 0.5 mm (calculated based on the height of the ring structure on the side of the porous reinforcing substrate 1 with a denser ring structure), and the distribution density is 400 rings / cm². 2 ; S4, Needle-based fixation First-stage solidification: The initial needle is made using a triangular straight needle with a needle density of 60 needles / cm². The purpose of this step is to gently and physically entangle and lock the root of the micro-ring structure 3 formed in S3 with the substrate, thus completing the basic solidification and avoiding damage to the formed ring surface in subsequent high-density needles. Secondary consolidation: such as Figure 2 As shown, continue to use triangular straight needles for secondary needling, with a needling density of 150 needles / cm², to form a coarse product with a smooth velvet surface; S5, Post-processing The crude material is heat-set, sheared, brushed, and softened to obtain reinforced ultrathin natural fiber felt. The heat-setting conditions are: heat-set at 130℃ for 2 minutes. The surface micrograph of the resulting natural fiber felt is shown below. Figure 3 As shown.

[0036] Example 2 An enhanced ultrathin natural fiber felt differs from Example 1 in that the specific operation of secondary compaction in S5 is as follows: Using a forked needle, needle punching is performed at a density of 120 needles / cm² to obtain a coarse textured terry cloth surface. Microscopic images of the surface of the prepared natural fiber felt are shown below. Figure 4 As shown.

[0037] Example 3 An enhanced ultrathin natural fiber felt differs from Example 1 in that the average pore size of the mesh 11 in its porous reinforcing substrate 1 is 0.5 mm, while the remaining steps are the same as in Example 1.

[0038] Example 4 An enhanced ultrathin natural fiber felt differs from Example 1 in that the average pore size of the mesh 11 in its porous reinforcing substrate 1 is 5 mm, while the remaining steps are the same as in Example 1.

[0039] Example 5 An enhanced ultrathin natural fiber felt differs from Example 1 in that the negative pressure value in S3 is 0.5 kPa, but the pressure value is relatively small, and the time needs to be increased to 10 s to fully form a uniform micro-ring structure 3. The remaining steps are the same as in Example 1.

[0040] Example 6 An enhanced ultrathin natural fiber felt differs from Example 1 in that the negative pressure value in S3 is 8 kPa. Due to its large negative pressure value, the time needs to be reduced to 1 second to fully form a uniform micro-ring structure 3. The remaining steps are the same as in Example 1. Comparative Example

[0041] Comparative Example 1 An enhanced ultrathin natural fiber felt differs from Example 1 in that it omits step S3, directly proceeding to the needle-punching and compaction step. Furthermore, this needle-punching and compaction step utilizes triangular straight needles, performing a single-pass needle-punching at a density of 210 needles / cm² (60 + 150 needles / cm², the total density is the same as in Example 1). This is because, in actual operation, if the original needle-punching and compaction step is followed, the single-pass needle-punching density is insufficient, making the finished product difficult to form. The remaining steps are the same as in Example 1. The surface micrograph of the resulting natural fiber felt is shown below. Figure 5 As shown.

[0042] Comparative Example 2 An enhanced ultrathin natural fiber felt differs from Example 1 in that it does not use porous reinforcing substrate 1, and the basis weight of its fiber web is modified to 180 g / m² (total basis weight is the same as in Example 1). The fiber web is directly laid on the support screen. Since there is no porous reinforcing substrate 1, step S3 is omitted. In the needle-punching and compaction step S4, triangular straight needles are used directly, and needle-punching is performed at a density of 210 needles / cm². The remaining steps are the same as in Example 1. The surface micrograph of the obtained natural fiber felt is shown below. Figure 6 As shown.

[0043] Performance testing Detection methods / test methods

[0044] Natural fiber felts were prepared according to the preparation methods of Examples 1-6 and Comparative Examples 1-2, and then tested according to the following testing methods. The test results are shown in Tables 1 and 2.

[0045] Thickness: Measured under specified pressure according to GB / T 3820-1997; Weight: Measured according to GB / T 4669-2008; Fracture strength: determined according to GB / T 3923.1-2013 using the strip method; Anti-pilling property: According to GB / T 4802.1-2008 (circular trajectory method), it is rated after 5000 tests, with 5 being the best and 1 being the worst; Abrasion resistance test: According to GB / T 21196.2-2007 (Martindale method), the number of revolutions required for the fabric to abrade to breakage (or the occurrence of a specified number of yarn breaks) under a specified pressure is tested; Dimensional stability test: According to GB / T 8629-2017, the dimensional change rate (%) of the sample after multiple water washing cycles was tested; Air permeability test: According to GB / T 5453-1997, the test measures the airflow rate that passes vertically through a unit area of ​​fabric per unit time under a specified pressure difference.

[0046] Objective evaluation was conducted using the Kawabata Fabric Style Analyzer (KES-FB) system, and tests were performed according to FZ / T 01053-2007 "Objective Evaluation of Fabric Style" and related methods, focusing on the following core indicators: Bending Stiffness (G / cm²·cm): Characterizes the stiffness and drape of a fabric; the smaller the value, the softer the fabric. Coefficient of Friction (MIU): Characterizes the smoothness of a surface; the smaller the value, the smoother the surface. Compression Resilience (RC): Characterizes the fullness and resilience of a fabric. The higher the value, the more fluffy and elastic the fabric.

[0047] Table 1. Detection results of Examples 1-2 and Comparative Examples 1-2

[0048] Table 2. Detection results of Examples 1 and 3-6

[0049] As can be seen from Examples 1-6, Comparative Examples 1-2, and the test data in Table 1-2, this application successfully prepared high-performance reinforced ultra-thin fiber felt by introducing the "airflow pre-ringing" step and combining the porous reinforcing substrate 1 with a refined needle punching process. The weight of the natural fiber felt is around 180 g / m², the thickness is less than 1 mm, the air permeability is between 1050-1250 mm / s, the longitudinal breaking strength is 270 N or higher, with a maximum of 285 N, the coefficient of friction is as low as 0.12, and other properties are also excellent. Its comprehensive performance is far superior to existing technology products, while meeting the market demand for lightweight, high strength and comfortable surface feel, and has extremely high market application value.

[0050] The test data from Example 1 and Comparative Example 1 show that, using the same raw materials and total needle-punching density, Example 1, due to the addition of the core airflow pre-ringing step, exhibits a significantly reduced thickness, a substantial improvement in anti-pilling and anti-fuzzing properties, and a dramatic improvement in the feel evaluation from "distinctly prickly" to "extremely smooth." This fully demonstrates the decisive role of the airflow pre-ringing step in improving the surface quality and feel of the product. In conjunction with Examples 5-6, the negative pressure value in the airflow pre-ringing step should not be less than 0.5 kPa or greater than 8 kPa, and is preferably within the range of 0.5-8 kPa.

[0051] The test data from Example 1 and Comparative Example 2 show that, with the same total basis weight, Comparative Example 2, lacking the porous reinforcing substrate 1, has a tensile strength of only about 30% of that of Example 1, and its thickness is nearly three times greater, making it completely unable to achieve the goal of "ultra-thin, high-strength". This demonstrates the necessity of the porous reinforcing substrate for achieving the purpose of this application. In conjunction with Examples 3-4, the pore size of the porous reinforcing substrate 1 is also an important factor affecting product performance; a pore size within the range of 0.5-5 mm is preferable.

[0052] Based on this, the natural fiber felts of Examples 1, 2, and Comparative Example 1 exhibited very low dimensional change rates (-1.5% to -1.8%), demonstrating excellent dimensional stability and reaching the level of high-quality woven fabrics. Comparative Example 2, however, had a dimensional change rate as high as -12.0%, resulting in severe felting shrinkage and deformation, essentially rendering it unwashable. This indicator clearly demonstrates the "skeleton" role of the porous reinforcing substrate. All samples containing the porous reinforcing substrate 1 (Examples 1, 2, and Comparative Example 1) had their dimensions firmly locked, effectively resisting the tendency of wool fibers to naturally felt under humid and hot conditions. Comparative Example 2, as a pure wool felt without the porous reinforcing substrate 1, clearly revealed its shortcomings. This comparison strongly supports the necessity of combining wool with the porous reinforcing substrate 1 in this application.

[0053] The test data from Examples 1-2 show that by adjusting the needle type (straight needle vs. forked needle) during secondary needle punching, the final thickness and surface feel of the product (smooth velvet vs. three-dimensional terry cloth) can be effectively adjusted while maintaining excellent basic performance, demonstrating the high designability and flexibility of the process in this application. Example 1 (>50,000) exhibited good abrasion resistance, remaining undamaged even after reaching the upper limit of the high-strength textile test; Example 2 (35,000) also showed good abrasion resistance, significantly higher than conventional felt, but slightly lower than Example 1, because the three-dimensional loops have more stress points under long-term friction than a smooth surface, yet remain extremely strong. Comparative Examples 1 (4,000) and 2 (3,000) showed poor abrasion resistance. They exhibited severe wear and holes after relatively few cycles of friction. The surfaces of Examples 1 and 2 consist of complete micro-ring structures 3 anchored by the porous reinforcing substrate 1. During friction, the force is applied to the strong sides of the fibers, rather than the weak ends. Conversely, the surfaces of Comparative Examples 1 and 2 were covered with free fiber ends. The friction head used in the Martindale test easily pulled out and broke these ends, causing rapid surface damage. This demonstrates that the airflow pre-ring process of this application has a decisive, order-of-magnitude improvement in the abrasion resistance of felt.

[0054] Examples 1 (1100), 2 (1250), and Comparative Example 1 (1150) all exhibited excellent breathability, with values ​​at a high level. Example 2, with its slightly fluffy three-dimensional terry structure, demonstrated the best breathability. Comparative Example 2 (350) exhibited the worst breathability, significantly lower than the other samples. This data demonstrates that the present invention achieves "ultra-thin, high-strength" without sacrificing the natural breathability and comfort of wool. Although the structure is dense, the overall thickness is thin, and the fibers are arranged in an orderly manner, allowing for effective airflow. Comparative Example 2, due to its own thickness and the severe felting of its internal fibers, blocked airflow channels, resulting in a sharp decrease in breathability.

[0055] This specific embodiment is merely an explanation of the present invention and is not intended to limit the invention. After reading this specification, those skilled in the art can make modifications to this embodiment without contributing any inventive step, but such modifications are protected by patent law as long as they are within the scope of the claims of the present invention.

Claims

1. A method for preparing an enhanced ultrathin natural fiber felt, characterized in that: It includes the following steps: S1. Substrate Preparation Take the porous reinforced substrate (1) and place it on the support net curtain; S2, Fiber mesh laying Natural fibers (2) are prepared to form a fiber web, and then the fiber web is laid flat on the porous reinforced substrate (1); S3, airflow pre-formed ring By applying negative pressure to the side of the fiber mesh away from the fiber mesh, the natural fibers (2) in the fiber mesh form a micro-ring structure (3) on the porous reinforcing substrate (1). S4, Needle-based fixation A crude product is obtained by performing one and two acupuncture sessions, or by performing multiple acupuncture sessions after one acupuncture session, with the acupuncture density of the two sessions being greater than that of the one session. S5, Post-processing The coarse product is heat-set, sheared and / or brushed, and / or softened to obtain an enhanced ultra-thin natural fiber felt; the porous reinforced substrate (1) has a mesh (11) with a pore size range of 0.5-5mm; The basis weight of the porous reinforced substrate (1) is 30-150 g / m², the basis weight of the fiber web is 80-200 g / m², and the fineness of the natural fiber (2) is 14-24 μm. In step S3, the negative pressure is 0.5-8 kPa, and the negative pressure is applied for 1-10 seconds. The height of the micro-ring structure (3) is 0.1-10 mm, and the distribution density is 50-500 per cm². In step S4, the needle density of the first acupuncture is 40-80 needles / cm², and the needle density of the second acupuncture is 80-200 needles / cm².

2. The method for preparing an enhanced ultrathin natural fiber felt according to claim 1, characterized in that: The porous reinforced substrate (1) is a polymer fiber mesh, metal wire mesh or natural fiber mesh.

3. The method for preparing an enhanced ultrathin natural fiber felt according to claim 2, characterized in that: The polymer fiber web is a warp-knitted, weft-knitted, or nonwoven fabric made of one or more of polyamide fibers, polyester fibers, and polypropylene fibers.

4. The method for preparing an enhanced ultrathin natural fiber felt according to claim 1, characterized in that: The natural fiber (2) is one or more of wool, cashmere, camel hair, and rabbit hair.

5. A reinforced ultrathin natural fiber felt, characterized in that: The reinforced ultrathin natural fiber felt is prepared by the preparation method of any one of claims 1-4.

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