A method for preparing a long / short pile hybrid flocked waterproof fabric by electrostatic flocking

Abstract

This invention discloses a method for preparing a long / short pile mixed flocked waterproof fabric using electrostatic flocking, belonging to the field of materials. The method involves electrostatically implanting long and short piles onto a fabric coated with an adhesive using electrostatic flocking technology. After baking and setting, the fabric is immersed in a hydrophobic agent for hydrophobic finishing, followed by drying and baking to obtain the long / short pile mixed flocked waterproof fabric. This composite structure maximizes air trapping and is uniformly coated with a low surface energy material during subsequent hydrophobic finishing, resulting in a synergistic effect that significantly reduces the actual contact area between water droplets and fibers, achieving a better water contact angle and hydrophobic effect. Simultaneously, the mutual support between the long and short piles creates a "structural interlocking" effect, making the pile less prone to flattening or falling off after hydrophobic finishing, thus enhancing the durability of the hydrophobic layer and possessing broad market application value.

Description

Technical Field

[0001] This invention relates to a method for preparing a long / short pile mixed flocked waterproof fabric by electrostatic flocking, belonging to the field of materials. Background Technology

[0002] Electrostatic flocking is a functional surface finishing technology that uses a high-voltage electrostatic field to vertically implant short fibers into an adhesive-coated substrate, forming a vertically piled surface. Its core lies in precisely controlling fiber orientation through an electric field to construct a unique array of microstructures. Traditionally, it has been widely used in automotive interiors, home décor, and apparel fabrics. In recent years, this technology has been rapidly expanding into functional fields, particularly in waterproof and breathable textiles. It is used to create superhydrophobic surfaces, achieve directional perspiration management, and serve as a framework for smart composite materials. This provides innovative solutions for developing advanced textiles with high comfort and adaptive thermal and moisture management, demonstrating the potential for a paradigm shift from decoration to function.

[0003] The application of electrostatic flocking technology in the waterproof and breathable field represents a cutting-edge direction in controlling the transport of liquid and gaseous water through precise surface structure design, and is undergoing a paradigm shift from traditional decorative techniques to functional innovation. The core of this technology lies in using a high-voltage electrostatic field to drive short fibers vertically implanted into the surface of a substrate coated with an adhesive, forming a dense, ordered array of upright fibers after curing. This unique microstructure endows the fabric surface with anisotropic physical properties, providing new ideas to overcome the limitations of traditional high-density fabrics, coatings, or laminated films, and showing unique potential, particularly in constructing active moisture management systems. Its specific application mechanisms mainly revolve around three major directions: First, constructing a superhydrophobic surface. Through the micro-nano double roughness structure formed by flocking, combined with low surface energy finishing, the fabric can obtain a high contact angle and low roll-off angle similar to the "lotus effect," achieving excellent water-repellent and stain-resistant properties. This characteristic has been verified in fields such as drag reduction in shipping. Second, achieving directional moisture wicking and perspiration management. By designing the physical structure of the fiber array or performing hydrophilic-hydrophobic differential treatment on the fibers, a wetting gradient is created, thereby guiding liquid sweat on the skin surface to transfer unidirectionally outward and spread and evaporate quickly, while effectively blocking the reverse penetration of external liquid water. This anisotropic liquid management capability based on capillary effect significantly improves dynamic wearing comfort. Third, as a reinforcing skeleton for functional composite materials, the flocked layer is combined with polymers such as hydrophilic polyurethane. The vertical fibers act as pillars, forming stable microchannels within the functional membrane, synergistically improving the mechanical support, hydrostatic pressure resistance, and moisture permeability of the composite material.

[0004] However, achieving reliable high-performance applications of this technology still faces a series of severe challenges. Durability and fastness are the biggest bottlenecks. Its function is highly dependent on the adhesion of the adhesive to the base fabric and flocking, as well as its water resistance and washability. Repeated friction, bending, and washing can easily cause fibers to fall off or flatten, resulting in a sharp decline in function. Industry standards (such as FZ / T 64011-2012 "Electrostatic Flocking Fabrics") have long listed "flocking fastness" as a key assessment indicator. The challenge of balancing function and durability is equally prominent. High water resistance requires a dense structure, while high moisture permeability requires porous and unobstructed flow. Although a simple flocking structure is conducive to moisture permeability, its waterproofing capacity is limited. To achieve high protection, it is often necessary to combine it with a coating, which may sacrifice moisture permeability and hand feel.

[0005] Electrostatic flocking technology involves a flocking process in a high-voltage electrostatic field. When the flock fibers pass through electrodes, they acquire a negative charge, while the substrate coated with adhesive is placed at zero potential or grounded. Under the influence of the electric field, the charged fibers accelerate and fly vertically towards the substrate surface, inserting into the adhesive layer. After heating and curing, a firm, upright flocked surface is formed. Subsequent hydrophobic finishing can achieve even better waterproofing.

[0006] However, existing electrostatic flocking methods often use flocks of a single length. To refine the waterproof effect and hand feel of flocked fabrics, the flock length can be appropriately increased. However, when the flock is long, problems such as uneven flocking, flattening, and weak bonding often arise during the preparation process. Improper flock selection, such as mismatched length or fineness, can also lead to uneven flocking, poor fastness, or difficulty in controlling static electricity. Subsequent hydrophobic finishing introduces new problems, such as soaking causing the flock to flatten, and improper baking temperature / time damaging the flock or affecting the hand feel. Furthermore, the limited surface roughness formed by a single structure restricts the upper limit of the waterproof performance improvement after hydrophobic finishing. Summary of the Invention

[0007] To address the shortcomings of existing technologies, the present invention aims to provide a method for preparing a long / short pile mixed flocked waterproof fabric using electrostatic flocking. This method involves sequentially flocking long and short piles onto a cotton fabric thoroughly coated with adhesive using electrostatic flocking equipment, followed by baking to obtain the long / short pile mixed flocked fabric. During this process, the flocking time ratio is adjusted to achieve different proportions of long and short piles in the prepared fabric. The flocking order of the long and short piles is also controlled to pursue better hydrophobic properties in the final product. The flocked fabric is then immersed in a hydrophobic agent for a period of time and subsequently dried in an oven and baked in a baking machine to obtain the long / short pile mixed flocked waterproof fabric. The long and short piles of this fabric together form a "micro-nano hierarchical rough structure," which allows it to be uniformly coated with low surface energy materials during subsequent hydrophobic finishing, thus synergistically reducing the actual contact area between water droplets and fibers, achieving a better water contact angle and hydrophobic effect. Simultaneously, the mutual support between the long and short piles creates a "structural interlocking" effect, making the pile less prone to flattening or falling off after hydrophobic finishing, thus enhancing the fabric's durability.

[0008] To achieve the above objectives, the following technical solution is provided: The first objective of this invention is to provide a method for preparing a long / short pile mixed flocked waterproof fabric by electrostatic flocking, the method comprising the following steps: (1) Using electrostatic flocking technology, long and short fibers are electrostatically implanted into the fabric coated with adhesive, and then baked and shaped to obtain a long / short fiber mixed flocked fabric without hydrophobic finishing. (2) The long / short pile mixed flocked fabric obtained in step (1) is immersed in a hydrophobic agent for hydrophobic finishing, and then dried and baked to obtain a long / short pile mixed flocked waterproof fabric.

[0009] In one embodiment, the fabric in step (1) is untreated cotton.

[0010] In one embodiment, the specifications of the long pile in step (1) range from 15D×2.5mm to 15D×5mm; the specifications of the short pile range from 6D×0.8mm to 6D×1.5mm.

[0011] In one embodiment, the voltage of the electrostatic flocking in step (1) is 50~70kV, the current is set to 110~120uA, and the electrode spacing is 6~10cm.

[0012] In one embodiment, the long and short fibers in step (1) are implanted sequentially; preferably, the long fibers are implanted first, followed by the short fibers; or the short fibers are implanted first, followed by the long fibers.

[0013] In one embodiment, the electrostatic flocking in step (1) is a lower flocking method.

[0014] In one embodiment, the time ratio of the long and short fibers electrostatic implantation in step (1) is 2~8:8~2.

[0015] In one embodiment, the materials of the long and short fibers in step (1) are nylon.

[0016] In one embodiment, the fabric coated with adhesive in step (1) specifically refers to applying a sufficient amount of adhesive evenly to the surface of a cotton fabric and waiting for 1 minute until the adhesive fully soaks the cotton fabric, and then removing the excess adhesive from the surface of the cotton fabric by squeezing to obtain the fabric coated with adhesive.

[0017] In one embodiment, the electrostatic flocking technology in step (1) uses a WX-ZR-1 portable electrostatic flocking machine.

[0018] In one embodiment, the nozzle of the electrostatic flocking machine is a circle with a diameter of 10cm.

[0019] In one embodiment, the preferred method for electrostatically implanting long and short fibers onto the fabric coated with adhesive using electrostatic flocking technology in step (1) is as follows: using an electrostatic flocking machine to first implant long fibers and then implant short fibers, with the implantation time ratio of long fibers to short fibers being 8~2:2~8; or using an electrostatic flocking machine to first implant short fibers and then implant long fibers, with the implantation time ratio of short fibers to long fibers being 8~2:2~8.

[0020] In one embodiment, the baking parameters in step (1) are 150~180℃ and the time is 30~60s.

[0021] In one embodiment, the soaking time in step (2) is 1 to 5 minutes.

[0022] In one embodiment, the hydrophobic agent described in step (2) needs to be diluted with deionized water at a volume ratio of 8:92 before use to ensure uniform distribution and penetration.

[0023] In one embodiment, the drying temperature in step (2) is 80~120℃ and the time is 1~5h.

[0024] In one embodiment, the baking temperature in step (2) is 150~180℃ and the time is 30~60s; the purpose of baking is to promote the cross-linking reaction between the hydrophobic finishing agent and the plush.

[0025] A second objective of this invention is to provide a long / short pile mixed flocked waterproof fabric prepared by the method described above.

[0026] A third objective of this invention is to provide an application of the aforementioned long / short pile mixed flocked waterproof fabric in furniture decoration, clothing accessories, vehicle interiors, and functional industrial fabrics.

[0027] A fourth objective of this invention is to provide a method for improving the hydrophobic durability of a long / short pile blend flocked waterproof fabric, the method comprising the following steps: (1) Using electrostatic flocking technology, long and short fibers are electrostatically implanted into the fabric coated with adhesive, and then baked and shaped to obtain a long / short fiber mixed flocked fabric without hydrophobic finishing. (2) The long / short pile mixed flocked fabric obtained in step (1) is immersed in a hydrophobic agent for hydrophobic finishing, and then dried and baked to obtain a long / short pile mixed flocked waterproof fabric.

[0028] Beneficial effects: This invention achieves optimal performance of long / short pile mixed flocked waterproof fabric by addressing both the long / short pile ratio and the flocking order through gradient variation design. This method of mixed flocking imparts a "micro-nano hierarchical rough structure" to the flocked fabric. Short piles form the main framework, providing overall roughness, while long piles fill the gaps between short piles, creating a fine secondary rough structure. This composite structure maximizes air trapping and is uniformly coated with low surface energy materials during subsequent hydrophobic finishing, resulting in a synergistic effect that significantly reduces the actual contact area between water droplets and fibers, achieving better water contact angle and hydrophobic effect. Simultaneously, the mutual support between long and short piles creates a "structural interlocking" effect, preventing the pile from easily flattening or falling off after hydrophobic finishing, thus enhancing the durability of the hydrophobic layer. In addition, the combination of long and short pile gives the fabric surface a unique composite feel, with both the soft and fluffy feel of long pile and the fullness and density of short pile, making the style more distinctive; and this complex and stable layered structure also provides more possibilities for simultaneously loading other functional finishing agents. Attached Figure Description

[0029] Figure 1 Line graph comparing the water contact angles of four different long / short pile flocking time ratios of hydrophobic treated waterproof fabrics and four different short / long pile flocking time ratios of hydrophobic treated waterproof fabrics. Figure 2 The left figure is a bar chart comparing the water contact angles of short / long pile mixed flocked fabrics with the optimal short / long pile flocking time ratio (8 seconds for short pile flocking followed by 2 seconds for long pile flocking) before and after hydrophobic finishing; the right figure is a bar chart comparing the water contact angles of waterproof fabrics with pure long pile flocking, pure short pile flocking, and the optimal short / long pile flocking time ratio. Figure 3From left to right and top to bottom, the images show the water contact angles of a mixed flocked fabric (with short pile flocking for 8 seconds followed by long pile flocking for 2 seconds) without hydrophobic treatment, a pure short pile flocked waterproof fabric, a pure long pile flocked waterproof fabric, and a short / long pile mixed flocked waterproof fabric with the optimal short / long pile flocking time ratio.

[0030] Figure 4 The left and right images are, respectively, cold field scanning electron microscope images of the cross-sectional morphology of the pure long-pile flocked waterproof fabric of Example 1 and the long / short pile mixed flocked waterproof fabric of Example 5 with optimal process parameters after the pile durability was verified. Detailed Implementation

[0031] It should be understood that the specific embodiments listed below do not constitute a limitation on the scope of the present invention, and the process steps involved should not be construed as mandatory requirements for their order of operation. Any modifications or variations that can be easily conceived by those skilled in the art based on common sense of the prior art also fall within the legal protection scope declared by the claims of the present invention.

[0032] The testing method involved in this invention: 1. Water contact angle test of fabric Flocked fabrics prepared with different process parameters were cut into strips of 0.5cm × 3cm and attached to glass slides with double-sided tape. The water contact angle of the fabrics was measured using an SDC-100H contact angle meter. The dispensing volume of the micro-injector was controlled at 10 microliters during each measurement. Multiple measurements were taken, and the average of the results was calculated.

[0033] 2. Fabric nap durability test The prepared flocked fabric was rubbed back and forth ten times with a brush; then the cross-sectional morphology of the mixed flocked fabric and the single-length flocked fabric after rubbing was observed and compared with that of the Hitachi SU8100 cold field emission scanning electron microscope.

[0034] Compare with Example 1 A method for preparing a pure long-pile flocked waterproof fabric includes the following steps: (1) Cut the untreated plain cotton fabric into a 10cm×10cm square and place it in a petri dish. Use a dropper to apply the adhesive DM-5128 (formaldehyde-free, Demei brand) to the surface of the cotton fabric. Wait 1 minute for the adhesive to fully penetrate the cotton fabric. Then lay the cotton fabric flat and put it into a self-sealing bag. Remove the excess adhesive from the surface by squeezing. (2) Ground the electrostatic flocking machine, add 20g of long flock with a specification of 15D×3mm into the flock box of the electrostatic flocking machine, set the applied voltage to 60kV and the working current to 120uA; Turn on the machine, select a plate spacing of 7cm, and use the descent flocking method to implant long fibers into cotton fabric coated with adhesive. The flocking process lasts for 10 seconds. (3) Place the flocked fabric into a baking machine and bake it at 150°C for 60 seconds to obtain pure long-pile flocked fabric without hydrophobic treatment. (4) Dilute the hydrophobic finishing agent 6118NA (Demei brand) and deionized water at a volume ratio of 8:92 and pour them into a petri dish; place the pure long-pile flocked fabric obtained in (3) into a petri dish containing the hydrophobic finishing agent and soak for 1 minute for hydrophobic finishing. (5) Place the hydrophobic treated fabric into an oven and dry it at 105℃ for 1 hour until it is dry; (6) Place the dried fabric into a baking machine and bake at 170°C for 60 seconds to promote the cross-linking effect between the hydrophobic finishing agent and the pile. After baking, a pure long-pile flocked waterproof fabric is obtained.

[0035] The fabric was subjected to three contact angle tests and the average value was taken. The water contact angle of the fabric was measured to be 125.5°.

[0036] Compare with Example 2 A method for preparing a pure short-pile flocked waterproof fabric includes the following steps: (1) Cut the untreated plain cotton fabric into a 10cm×10cm square and place it in a petri dish. Use a dropper to apply the adhesive to the surface of the cotton fabric and wait for 1 minute to allow the adhesive to fully penetrate the cotton fabric. Then lay the cotton fabric flat and put it into a self-sealing bag. Remove the excess adhesive from the surface by squeezing. (2) Ground the electrostatic flocking machine, add 20g of short flock with a specification of 6D×1.5mm into the flock box of the electrostatic flocking machine, set the applied voltage to 60kV and the working current to 120uA; Turn on the machine, select a plate spacing of 7cm, and use the descent flocking method to implant short fibers into the cotton fabric coated with adhesive. The flocking process lasts for 10 seconds. (3) Place the flocked fabric into a baking machine and bake it at 150°C for 60 seconds to obtain pure short-pile flocked fabric without hydrophobic treatment. (4) Dilute the hydrophobic finishing agent 6118NA and deionized water at a volume ratio of 8:92 and pour them into a petri dish; place the pure short-pile flocked fabric obtained in (3) into a petri dish containing the hydrophobic finishing agent and soak for 1 minute for hydrophobic finishing. (5) Place the hydrophobic treated fabric into an oven and dry it at 105℃ for 1 hour until it is dry; (6) Place the dried fabric into a baking machine and bake at 170°C for 60 seconds to promote the cross-linking effect between the hydrophobic finishing agent and the pile. After baking, a pure short pile flocked waterproof fabric is obtained.

[0037] The fabric was subjected to three contact angle tests and the average value was taken. The water contact angle of the fabric was measured to be 134.3°.

[0038] Compare with Example 3 A method for preparing a short / long pile blend flocked fabric without hydrophobic finishing, comprising the following steps: (1) Cut the untreated plain cotton fabric into a 10cm×10cm square and place it in a petri dish. Use a dropper to apply the adhesive DM-5128 to the surface of the cotton fabric and wait for 1 minute to allow the adhesive to fully penetrate the cotton fabric. Then lay the cotton fabric flat and put it into a self-sealing bag. Remove the excess adhesive from the surface by squeezing. (2) Ground the electrostatic flocking machine, add 20g of short flock with a specification of 6D×1.5mm into the flock box of the electrostatic flocking machine, set the applied voltage to 60kV and the working current to 120uA; Turn on the machine, select a plate spacing of 7cm, and use the descent flocking method to first implant short fibers into the cotton fabric coated with adhesive. The flocking process lasts for 8 seconds. Turn off the machine, collect all remaining 6D×1.5mm short fibers in the flock box of the electrostatic flocking machine and replace them with 20g of 15D×3mm long fibers; With the power on, the external voltage, operating current and electrode spacing parameters remain unchanged. The long fibers are then implanted onto the cotton fabric that has already been planted with short fibers using the descent flocking method. The flocking process lasts for 2 seconds. (3) Place the flocked fabric into a baking machine and bake it at 150°C for 60 seconds to obtain a short / long pile mixed flocked fabric without hydrophobic treatment.

[0039] The fabric was subjected to three contact angle tests and the average value was taken. The water contact angle of the fabric was measured to be 125.7°.

[0040] Example 1 A method for preparing a long / short pile mixed flocked waterproof fabric includes the following steps: (1) Cut the untreated plain cotton fabric into a 10cm×10cm square and place it in a petri dish. Use a dropper to apply the adhesive fully to the surface of the cotton fabric and wait for 1 minute to allow the adhesive to fully penetrate the cotton fabric. Lay the cotton fabric flat and put it into a self-sealing bag. Remove the excess adhesive from the surface by squeezing. (2) Ground the electrostatic flocking machine, add 20g of long flock with a specification of 15D×3mm into the flock box of the electrostatic flocking machine, set the applied voltage to 60kV and the working current to 120uA; Turn on the machine, select a plate spacing of 7cm, and use the descent flocking method to first implant long fibers into cotton fabric coated with adhesive. The flocking process lasts for 8 seconds. Turn off the machine, collect all remaining 15D×3mm long fibers in the flock box of the electrostatic flocking machine and replace them with 20g of short fibers with a specification of 6D×1.5mm. With the power on, the external voltage, operating current and electrode spacing parameters remain unchanged. The short fibers are then implanted onto the cotton fabric that has already been planted with long fibers using the descent flocking method. The flocking process lasts for 2 seconds. (3) Place the flocked fabric into a baking machine and bake it at 150°C for 60 seconds to obtain a long / short pile mixed flocked fabric without hydrophobic treatment. (4) Dilute the hydrophobic finishing agent 6118NA and deionized water at a volume ratio of 8:92 and pour them into a petri dish; place the long / short pile mixed flocked fabric obtained in (3) into a petri dish containing the hydrophobic finishing agent and soak for 1 minute for hydrophobic finishing. (5) Place the hydrophobic treated fabric into an oven and dry it at 105℃ for 1 hour until it is dry; (6) Place the dried fabric into a baking machine and bake at 170°C for 60 seconds to promote the cross-linking effect between the hydrophobic finishing agent and the pile. After baking, a long / short pile mixed flocked waterproof fabric is obtained.

[0041] The fabric was subjected to three contact angle tests and the average value was taken. The water contact angle of the fabric was measured to be 144°.

[0042] Example 2 The only difference from Example 1 is that the flocking time for long pile is adjusted to 6s and the flocking time for short pile is adjusted to 4s in step (2); all other parameters and conditions are the same as in Example 1.

[0043] The fabric was subjected to three contact angle tests and the average value was taken. The water contact angle of the fabric was measured to be 134.7°.

[0044] Example 3 The only difference from Example 1 is that the long pile flocking time in step (2) is adjusted to 4s and the short pile flocking time is adjusted to 6s; all other parameters and conditions are the same as in Example 1.

[0045] The fabric was subjected to three contact angle tests and the average value was taken. The water contact angle of the fabric was measured to be 135.7°.

[0046] Example 4 The only difference from Example 1 is that the long pile flocking time in step (2) is adjusted to 2s and the short pile flocking time is adjusted to 8s; all other parameters and conditions are the same as in Example 1.

[0047] The fabric was subjected to three contact angle tests and the average value was taken. The water contact angle of the fabric was measured to be 125.7°.

[0048] Example 5 A method for preparing a short / long pile mixed flocked waterproof fabric includes the following steps: (1) Cut the untreated plain cotton fabric into a 10cm×10cm square and place it in a petri dish. Use a dropper to apply the adhesive to the surface of the cotton fabric and wait for 1 minute to allow the adhesive to fully penetrate the cotton fabric. Then lay the cotton fabric flat and put it into a self-sealing bag. Remove the excess adhesive from the surface by squeezing. (2) Ground the electrostatic flocking machine, add 20g of short flock with a specification of 6D×1.5mm into the flock box of the electrostatic flocking machine, set the applied voltage to 60kV and the working current to 120uA; Turn on the machine, select a plate spacing of 7cm, and use the descent flocking method to first implant short fibers into the cotton fabric coated with adhesive. The flocking process lasts for 8 seconds. Turn off the machine, collect all remaining 6D×1.5mm short fibers in the flock box of the electrostatic flocking machine and replace them with 20g of 15D×3mm long fibers; With the power on, the external voltage, operating current and electrode spacing parameters remain unchanged. The long fibers are then implanted onto the cotton fabric that has already been planted with short fibers using the descent flocking method. The flocking process lasts for 2 seconds. (3) Place the flocked fabric into a baking machine and bake it at 150°C for 60 seconds to obtain a short / long pile mixed flocked fabric without hydrophobic treatment. (4) Dilute the hydrophobic finishing agent 6118NA and deionized water at a volume ratio of 8:92 and pour them into a petri dish; place the short / long pile mixed flocked fabric prepared in (3) into a petri dish containing the hydrophobic finishing agent and soak for 1 minute for hydrophobic finishing. (5) Place the hydrophobic treated fabric into an oven and dry it at 105℃ for 1 hour until it is dry; (6) Place the dried fabric into a baking machine and bake at 170°C for 60 seconds to promote the cross-linking effect between the hydrophobic finishing agent and the pile. After baking, a short / long pile mixed flocked waterproof fabric is obtained.

[0049] The fabric was subjected to three contact angle tests and the average value was taken. The water contact angle of the fabric was measured to be 145.8°.

[0050] Example 6 The only difference from Example 5 is that the short pile flocking time in step (2) is adjusted to 6s and the long pile flocking time is adjusted to 4s; all other parameters and conditions are the same as in Example 5.

[0051] The fabric was subjected to three contact angle tests and the average value was taken. The water contact angle of the fabric was measured to be 122.3°.

[0052] Example 7 The only difference from Example 5 is that the short pile flocking time in step (2) is adjusted to 4s and the long pile flocking time is adjusted to 6s; all other parameters and conditions are the same as in Example 5.

[0053] The fabric was subjected to three contact angle tests and the average value was taken. The water contact angle of the fabric was measured to be 135.5°.

[0054] Example 8 The only difference from Example 5 is that the short pile flocking time in step (2) is adjusted to 2s and the long pile flocking time is adjusted to 8s; all other parameters and conditions are the same as in Example 5.

[0055] The fabric was subjected to three contact angle tests and the average value was taken. The water contact angle of the fabric was measured to be 134.3°.

[0056] Results and Analysis Three contact angle tests were performed on each embodiment and the control example, and the average value was taken. The water contact angles of each example are shown in Table 1 below. Figures 1-3 ; Table 1. Water contact angles of fabrics obtained in various embodiments and comparative examples

[0057] Comparing Examples 1-4 with Examples 5-8, it was found that the water contact angle of the short / long pile mixed flocked waterproof fabric with each flocking time ratio is generally larger than that of the long / short pile mixed flocked waterproof fabric with each flocking time ratio. Furthermore, the hydrophobic performance of the mixed flocked waterproof fabric is best when the short pile is flocked for 8 seconds and the long pile is flocked for 2 seconds.

[0058] Comparing Example 5, which exhibits the best hydrophobic properties, with Comparative Examples 1-3, it was found that the contact angle of the flocked fabric with the optimal flocking process parameters of long / short pile mixed flocking after hydrophobic treatment is significantly greater than that of the flocked fabric with the optimal flocking process parameters of long / short pile mixed flocking without hydrophobic treatment, and is also significantly higher than that of waterproof flocked fabrics with only long pile or only short pile.

[0059] It is evident that the flocking strategy of long / short pile mixed flocking can effectively further improve the hydrophobicity of waterproof flocked fabrics. The flocking order of long and short piles significantly affects the hydrophobicity of the mixed flocked waterproof fabric, and the mixed flocked waterproof fabric prepared by flocking short piles first and then long piles has a better hydrophobic effect. This is because if long piles are flocked first, the flocking path of the short piles that are flocked later will be significantly blocked due to the high probability of irregular collapse of the already flocked long piles, thus increasing the flocking difficulty. However, when the short / long pile flocking time ratio is 8:2, the two form an optimal multi-level micro-nano rough structure and "interlocking effect". This composite structure can trap air to the maximum extent and be uniformly coated by low surface energy materials in the subsequent hydrophobic finishing, thus working synergistically to significantly reduce the actual contact area between water droplets and fibers, thereby increasing the water contact angle.

[0060] The durability of flocked fabrics was verified by observing the cross-sectional morphology using a cold field scanning electron microscope. Figure 4 The flocked fabric with optimal process parameters using a mixed flocking method exhibits strong interlocking between long and short fibers, resulting in a firm and densely distributed flock after ten rounds of brushing. In contrast, the flocked fabric made from a single 15D×3mm long fiber shows significant flattening and a much sparser flock distribution after friction. This demonstrates that the electrostatic flocking strategy using a mixed long / short fiber flocking method effectively improves the rubbing fastness and durability of flocked fabrics.

[0061] The embodiments provided above are not intended to limit the scope of the invention, nor are the described steps intended to limit the order of execution. Any obvious modifications made to the invention by those skilled in the art based on existing common knowledge also fall within the scope of protection defined by the claims.

Claims

1. A method for preparing a long / short pile mixed flocked waterproof fabric by electrostatic flocking, characterized in that, The method includes the following steps: (1) Using electrostatic flocking technology, long and short fibers are electrostatically implanted into the fabric coated with adhesive, and then baked and shaped to obtain a long / short fiber mixed flocked fabric without hydrophobic finishing. (2) The long / short pile mixed flocked fabric obtained in step (1) is immersed in a hydrophobic agent for hydrophobic finishing, and then dried and baked to obtain a long / short pile mixed flocked waterproof fabric.

2. The method according to claim 1, characterized in that, The specifications of the long pile in step (1) range from 15D×2.5mm to 15D×5mm; the specifications of the short pile range from 6D×0.8mm to 6D×1.5mm.

3. The method according to claim 1, characterized in that, The voltage of the electrostatic flocking in step (1) is 50~70kV, the current is set to 110~120uA, and the electrode spacing is 6~10cm.

4. The method according to claim 1, characterized in that, In step (1), the long and short fibers are implanted sequentially; preferably, the long fibers are implanted first, followed by the short fibers; or the short fibers are implanted first, followed by the long fibers.

5. The method according to claim 1, characterized in that, The time ratio of electrostatic implantation of long and short fibers in step (1) is 2~8:8~2.

6. The method according to claim 1, characterized in that, The preferred method for electrostatically implanting long and short fibers onto the adhesive-coated fabric using electrostatic flocking technology in step (1) is as follows: using an electrostatic flocking machine to first implant long fibers and then short fibers, with the implantation time ratio of long fibers to short fibers being 8~2:2~8; or using an electrostatic flocking machine to first implant short fibers and then long fibers, with the implantation time ratio of short fibers to long fibers being 8~2:2~8.

7. The method according to claim 1, characterized in that, The baking temperature in step (2) is 150~180℃ and the time is 30~60s; the purpose of baking is to promote the cross-linking reaction between the hydrophobic finishing agent and the plush.

8. The long / short pile mixed flocked waterproof fabric prepared by the method according to any one of claims 1 to 7.

9. The application of the long / short pile mixed flocked waterproof fabric as described in claim 8 in furniture decoration, clothing accessories, vehicle interiors, and functional industrial fabrics.

10. A method for improving the hydrophobic durability of a long / short pile blend flocked waterproof fabric, characterized in that, The method includes the following steps: (1) Using electrostatic flocking technology, long and short fibers are electrostatically implanted into the fabric coated with adhesive, and then baked and shaped to obtain a long / short fiber mixed flocked fabric without hydrophobic finishing. (2) The long / short pile mixed flocked fabric obtained in step (1) is immersed in a hydrophobic agent for hydrophobic finishing, and then dried and baked to obtain a long / short pile mixed flocked waterproof fabric.

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