Preparation method of one-way moisture-conducting quick-dry fabric

Abstract

The invention relates to the technical field of textile, and discloses a preparation method of a one-way moisture-conducting quick-dry fabric, which comprises the following steps: adding an anionic waterborne polyurethane dispersion, a cationic organosilicon microemulsion, a compound stabilizer, a blocked polyisocyanate cross-linking agent and glacial acetic acid into deionized water, stirring and mixing to obtain a finishing working solution; then carrying out padding treatment on base cloth in the finishing working solution; then, the wet cloth is guided into a direct-current electric field, the anionic waterborne polyurethane dispersoid is enriched towards the inner surface of the fabric under the action of the electric field, and the cationic organic silicon microemulsion is enriched towards the outer surface of the fabric. According to the invention, the anionic waterborne polyurethane dispersion and the cationic organosilicon microemulsion are mixed in the same finishing working solution, and the two components are respectively enriched on different surfaces of the fabric in one finishing process, so that the production process is simplified, and the control on the distribution of the finishing agent in the fabric is improved.

Description

Technical Field

[0001] This invention relates to the field of textile technology, specifically to a method for preparing a unidirectional moisture-wicking and quick-drying fabric. Background Technology

[0002] One-way moisture-wicking and quick-drying fabric is a functional textile designed to rapidly transfer sweat from the skin's surface to the outer layer of the fabric for evaporation, thus preventing the damp and cold feeling caused by sweat buildup and maintaining the body's dryness and physiological comfort. With the development of the high-performance sportswear and outdoor equipment market, the requirements for fabric moisture management capabilities are increasing, leading to the wider application of this type of fabric in related fields. The structural basis for achieving one-way moisture wicking is to construct a hydrophilic inner layer and a hydrophobic outer layer along the thickness direction of the fabric, forming a functional gradient.

[0003] Currently, to achieve this hydrophilic-inner and hydrophobic-outer structure in fabrics, some commonly used techniques employ multi-pass finishing processes, where the front and back sides of the fabric undergo independent hydrophilic and hydrophobic finishing respectively. This method not only increases production steps and equipment usage but also requires high alignment accuracy between the two processes, easily introducing production errors and affecting overall production efficiency. Other methods attempt to simplify the process through single-pass padding, but the formation of its functional gradient mainly depends on the passive migration of the finishing solution during the drying process. This migration process is affected by various factors such as the uniformity of the fabric's structure and the temperature and humidity distribution in the drying oven, making the process difficult to control precisely. This often results in blurred boundaries between the final hydrophilic and hydrophobic regions and an insufficiently clear gradient.

[0004] Regarding functional durability, in some existing finishing technologies, the binding force between functional finishing agents and fibers is relatively weak, relying mostly on physical adsorption. This makes it easy for functional additives to detach from the fiber surface after repeated wear and household washing, leading to a gradual decline in unidirectional moisture wicking performance and shortening the product's lifespan. Therefore, how to actively and controllably construct a stable hydrophilic and hydrophobic gradient structure fixed by chemical bonding in the fabric thickness direction within an integrated finishing process through simplified techniques is a problem that needs to be solved in this field. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention provides a method for preparing unidirectional moisture-wicking and quick-drying fabrics, which solves the problems of complex preparation processes, unstable functional gradients, and poor functional durability in existing unidirectional moisture-wicking functional fabrics.

[0006] To achieve the above objectives, the present invention adopts the following technical solution: a method for preparing a unidirectional moisture-wicking and quick-drying fabric, comprising the following steps: S1. Add anionic aqueous polyurethane dispersion, cationic silicone microemulsion, composite stabilizer, blocked polyisocyanate crosslinking agent and glacial acetic acid to deionized water, stir and mix to obtain finishing working solution; S2. The base fabric is immersed in the finishing solution to obtain a wet fabric; S3. The wet cloth is introduced into a DC electric field, with the cathode corresponding to the inner surface of the fabric and the anode corresponding to the outer surface of the fabric. The anionic aqueous polyurethane dispersion is enriched on the inner surface of the fabric and the cationic organosilicon microemulsion is enriched on the outer surface of the fabric by the electric field, thus obtaining a pre-separated wet cloth. S4. Apply high-temperature, high-speed hot air to the outer surface of the pre-separated wet cloth, and at the same time apply low-temperature, low-speed hot air to the inner surface of the pre-separated wet cloth to obtain a pre-dried fabric. S5. The pre-dried fabric is baked at high temperature to obtain a one-way moisture-wicking quick-drying fabric.

[0007] By adopting the above technical solution, this invention establishes a method for constructing and solidifying functionally graded structures using the synergistic effect of electric and thermal fields during a single-pass finishing process. The mechanism of action is described below: In step S1, anionic aqueous polyurethane with hydrophilic properties and cationic organosilicon with hydrophobic properties are mixed in the same working solution. The composite stabilizer inhibits the flocculation and sedimentation of these two functional particles with opposite charges through electrostatic repulsion and steric hindrance, thereby obtaining a homogeneous and stable mixed working solution.

[0008] In step S3, the wetted fabric after impregnation serves as the electrolyte medium. Under the influence of a DC electric field, charged particles in the working fluid undergo directional migration. Negatively charged anionic aqueous polyurethane migrates and accumulates on the inner surface of the fabric, i.e., the cathode side; positively charged cationic silicone microemulsion migrates and accumulates on the outer surface of the fabric, i.e., the anode side. This step establishes an initial concentration gradient of hydrophilic and hydrophobic functional agents along the fabric thickness direction.

[0009] In step S4, the high-temperature, high-speed hot air applied to the outer surface of the fabric causes a higher evaporation rate of moisture on that side compared to the inner side. This difference in evaporation rate produces two effects: first, the temperature gradient induces thermophoretic forces, prompting solute particles to move from the high-temperature zone to the low-temperature zone; second, the evaporation of moisture on the outer side creates a replenishing liquid flow from the inside out, which carries functional particles from the finishing solution outwards. These two effects work together to further concentrate hydrophobic agents in the outer layer of the fabric, while hydrophilic agents are retained in the inner layer, thus making the gradient distribution of functional agents more pronounced.

[0010] In step S5, high temperature causes the blocking groups of the blocked polyisocyanate crosslinking agent to detach, releasing isocyanate groups -NCO. These groups react with the end groups of the polyester fiber, the active hydrogen on the waterborne polyurethane and organosilicon molecular chains to form chemical crosslinks. Since the functional gradient structure has already been formed when the crosslinking reaction occurs, this step achieves in-situ chemical curing of the gradient distribution structure, forming an integrated network chemically bonded to the fiber, thereby endowing it with unidirectional moisture-wicking function and washability.

[0011] Preferably, the composite stabilizer is a compound of a nonionic surfactant and an amphoteric surfactant, and the preparation steps of the composite stabilizer include: Heat the deionized water to the preset temperature; Add a nonionic surfactant to deionized water while stirring, and stir until completely dissolved; Continue adding the amphoteric surfactant while stirring and at the preset temperature, stirring until the system is uniformly mixed; Stop heating and cool to room temperature to obtain the composite stabilizer.

[0012] By employing the above-described technical solution, a stable layer is formed on the surface of anionic and cationic polymer particles by utilizing the steric hindrance effect of nonionic surfactants and the electrostatic repulsion of amphoteric surfactants at a specific pH. The stabilizer prepared by this method can inhibit the contact and aggregation between particles with opposite charges, helping to maintain the stability of the mixed working solution during storage and use.

[0013] Preferably, in the preparation steps of the composite stabilizer, the preset temperature is 40-60℃; the stirring time after adding the nonionic surfactant is 15-20 minutes; and the stirring time after adding the amphoteric surfactant is 30-45 minutes.

[0014] By adopting the above technical solution, this temperature and time range helps the surfactant to dissolve and disperse, as well as form a stable composite structure in the system, providing raw materials that meet the process requirements for the subsequent preparation of finishing working solutions.

[0015] Preferably, the nonionic surfactant is fatty alcohol polyoxyethylene ether or octylphenol polyoxyethylene ether; the amphoteric surfactant is dodecyl dimethyl betaine or cocamidopropyl betaine.

[0016] By adopting the above technical solution, the specific chemicals for the stabilizer have been identified. This composition possesses the compatibility and stability required for the process of this invention.

[0017] Preferably, in step S1, the amount of each component used per liter of finishing working solution is as follows: Anionic aqueous polyurethane dispersion: 30–60 g; Cationic silicone microemulsion: 20–50 g; Composite stabilizer: 2-5g; Blocked polyisocyanate crosslinking agent: 10-25g; Glacial acetic acid: 0.5–1.5 g; Furthermore, the pH value of the treatment working solution is 5.0–6.0.

[0018] By adopting the above technical solution, this formulation range provides the required amounts of hydrophilic and hydrophobic functional agents, stabilizers, and crosslinking agents for the finishing process. Maintaining the pH value within a weakly acidic range provides a suitable chemical environment for the electric field separation in step S3 and helps maintain the charge characteristics and stability of each component in the system.

[0019] Preferably, the base fabric is polyethylene terephthalate fabric.

[0020] By adopting the above technical solution, the material of the base fabric has been specified. Polyethylene terephthalate fabric has high strength and durability, making it suitable for the finishing process of this invention.

[0021] Preferably, in step S2, the liquid retention rate of the base fabric after impregnation is controlled to be 70% to 80%.

[0022] By adopting the above technical solution, this liquid carrying rate range enables the fabric to carry the finishing working liquid required by the process, so that the material can migrate and be enriched in the subsequent electric field and thermal field separation steps.

[0023] Preferably, in step S3, the applied DC voltage is 50–200V, the electrode spacing is 10–30mm, and the time the fabric is subjected to the electric field is 2–3.6s.

[0024] By adopting the above technical solution, this parameter combination provides the electric field strength required to achieve directional particle migration within a specified time period, thereby completing the initial functional layering.

[0025] Preferably, in step S4, the temperature of the high-temperature, high-speed hot air is 120–150°C and the wind speed is 15–30 m / s; the temperature of the low-temperature, low-speed hot air is 70–90°C and the wind speed is 2–5 m / s.

[0026] By employing the above technical solution, a temperature and evaporation rate gradient is established between the two sides of the fabric. This gradient, as a further driving force to enhance the separation of functional agents, promotes the migration of hydrophobic agents to the outer surface and helps retain hydrophilic agents on the inner surface through the synergistic effect of thermophoresis and capillary wicking, making the functional gradient distribution more explicit.

[0027] Preferably, in step S5, the baking temperature is 150–170°C and the baking time is 45–90 seconds.

[0028] By adopting the above technical solution, the temperature and time provide the necessary conditions for the cross-linking reaction to proceed, allowing the blocked isocyanate to be unblocked and cross-link with the fiber and functional polymer, and the already formed functional gradient structure to be connected to the fiber through chemical bonds, thereby giving the fabric washability.

[0029] This invention provides a method for preparing a unidirectional moisture-wicking and quick-drying fabric. It has the following beneficial effects: 1. This invention achieves the separate enrichment of the two components on different surfaces of the fabric in one finishing process by mixing anionic aqueous polyurethane dispersion and cationic organosilicon microemulsion in the same finishing working solution, followed by padding, and then applying a DC electric field and hot air at different temperatures and velocities to the inner and outer surfaces of the fabric. This simplifies the production process and improves the control of the distribution of finishing agents in the fabric.

[0030] 2. In this invention, after enriching the anionic aqueous polyurethane dispersion and the cationic organosilicon microemulsion in the fabric, high-temperature baking is performed to cause the blocked polyisocyanate crosslinking agent to react, thereby solidifying the two enriched components onto the base fabric, so that the fabric has a one-way moisture-wicking function and washability.

[0031] 3. This invention first applies a DC electric field to enrich the anionic aqueous polyurethane dispersion on the inner surface of the fabric and the cationic organosilicon microemulsion on the outer surface of the fabric. Then, by applying high-temperature and high-speed hot air to the outer surface of the fabric and low-temperature and low-speed hot air to the inner surface, the difference in the rate of water evaporation on both sides of the fabric is utilized to further promote the enrichment of the two finishing agents on their respective corresponding surfaces, thus providing conditions for the final formation of a stable unidirectional moisture-wicking structure. Detailed Implementation

[0032] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the preparation examples, comparative examples, and test examples. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0033] Preparation Examples 1-3: Preparation Example 1: This preparation example aims to prepare the composite stabilizer CS-1.

[0034] Raw materials (by weight): Fatty alcohol polyoxyethylene ether (AEO-9, ethoxylation number 9): 40 parts; Dodecyl dimethyl betaine (BS-12, 30% aqueous solution): 30 parts; Deionized water: 30 parts.

[0035] Preparation steps: Add 30 parts of deionized water to a reaction vessel equipped with stirring and heating functions; Turn on the stirrer and heat to 50°C; While stirring, slowly add 40 parts of AEO-9 and stir for 15 minutes until completely dissolved; Slowly add 30 parts of BS-12 and continue stirring at 50°C for 30 minutes until the system is well mixed and becomes a homogeneous, transparent liquid. Stop heating and allow to cool naturally to room temperature to obtain composite stabilizer CS-1.

[0036] Preparation Example 2: This preparation example aims to prepare the composite stabilizer CS-2.

[0037] Raw materials (by weight): Octylphenol polyoxyethylene ether (OP-10, ethoxylation number 10): 30 parts; Cocamidopropyl betaine (CAB, 35% aqueous solution): 25 parts; Deionized water: 45 parts.

[0038] Preparation steps: Add 45 parts of deionized water to a reaction vessel equipped with stirring and heating functions; Turn on the stirrer and heat to 40°C; While stirring, slowly add 30 parts of OP-10 and stir for 15 minutes until completely dissolved; Slowly add 25 parts of CAB and continue stirring at 40°C for 30 minutes until the system is well mixed. Stop heating and allow to cool naturally to room temperature to obtain composite stabilizer CS-2.

[0039] Preparation Example 3: This preparation example aims to prepare the composite stabilizer CS-3.

[0040] Raw materials (by weight): Fatty alcohol polyoxyethylene ether (AEO-9, ethoxylation number 9): 50 parts; Cocamidopropyl betaine (CAB, 35% aqueous solution): 40 parts; Deionized water: 10 parts.

[0041] Preparation steps: In a reaction vessel equipped with stirring and heating functions, add 10 parts of deionized water; Turn on the stirrer and heat to 60°C; While stirring, slowly add 50 parts of AEO-9 and stir for 20 minutes until completely dissolved; Slowly add 40 parts of CAB and continue stirring at 60°C for 45 minutes until the system is well mixed and forms a uniform, transparent, viscous liquid. Stop heating and allow to cool naturally to room temperature to obtain composite stabilizer CS-3.

[0042] Examples 1-3: Example 1:

[0043] This embodiment provides a method for preparing a unidirectional moisture-wicking and quick-drying fabric, using a base fabric of 160g / m². 2 The polyethylene terephthalate plain knit fabric includes the following steps: S1. Preparation of the working bath: Add deionized water (80% of the total volume per liter of working solution) to a stirred tank, and start stirring. Add the following materials in sequence: 1.0 g / L glacial acetic acid, 3.5 g / L of the composite stabilizer CS-1 prepared in Preparation Example 1, 45 g / L of anionic aqueous polyurethane dispersion, and 18 g / L of blocked polyisocyanate crosslinking agent. Stir for 8 minutes after each addition. Finally, add 35 g / L of cationic silicone microemulsion under slow stirring, and replenish the remaining deionized water. Stir for 15 minutes to obtain the mixed working solution. Adjust and confirm the pH of the working solution to 5.5.

[0044] S2. Fabric Padding: The base fabric is introduced into the finishing tank, and the working solution temperature is maintained at 25℃. The fabric adopts a two-stage padding process, with the padding machine speed set at 20m / min. The roller pressure is adjusted to control the liquid retention rate of the fabric after padding at 75%.

[0045] S3. Electrophoretic Migration Pre-Separation: The wet cloth after impregnation is immediately introduced into the DC electric field separation unit. The electrode plate of this unit is 0.67m long, and the electrode spacing is set to 20mm. The cathode is aligned with the inner surface of the fabric (skin layer), and the anode is aligned with the outer surface of the fabric (surface layer). A DC voltage of 125V is applied, and the fabric is subjected to the electric field for 2s.

[0046] S4. Asymmetric Thermophoretic Migration and Oriented Fixation: The wet fabric, after electrophoretic pre-separation, is immediately introduced into the asymmetric hot air unit for pre-drying. Parameter settings are as follows: (1) Outer surface (surface layer, anode side): hot air temperature 135℃, hot air vertical blowing speed 22m / s.

[0047] (2) Inner surface (skin layer, cathode side): hot air temperature 80℃, hot air vertical blowing speed 3.5m / s.

[0048] S5. High-temperature baking (cross-linking curing): The fabric, after asymmetric pre-drying, is then placed in the baking zone of a standard hot air tenter frame. The baking temperature is set at 160℃, and the baking time is 60 seconds. After baking, the fabric is cooled, unloaded, and wound up to obtain the finished product.

[0049] Example 2:

[0050] This embodiment provides a method for preparing a unidirectional moisture-wicking and quick-drying fabric, using a base fabric of 140 g / m². 2 The polyethylene terephthalate plain knit fabric includes the following steps: S1. Preparation of the working bath: Based on the amount of working solution per liter, first add 80% deionized water to the stirred tank, and start stirring. Then add the following in sequence: 0.5 g / L glacial acetic acid, 2 g / L of the composite stabilizer CS-2 prepared in Preparation Example 2, 30 g / L of anionic aqueous polyurethane dispersion, and 10 g / L of blocked polyisocyanate crosslinking agent. Stir for 5 minutes after each addition. Finally, add 20 g / L of cationic silicone microemulsion under slow stirring, and replenish the remaining deionized water. Stir for 15 minutes to obtain the mixed working solution. Adjust and confirm that the pH of the working solution is 5.0.

[0051] S2. Fabric Padding: The base fabric is introduced into the finishing tank, and the working solution temperature is maintained at 20℃. The fabric adopts a two-stage padding process, with the padding machine speed set at 15m / min. The roller pressure is adjusted to control the liquid retention rate of the fabric after padding at 70%.

[0052] S3. Electrophoretic Migration Pre-Separation: The wet cloth after impregnation is immediately introduced into the DC electric field separation unit. The electrode plate of this unit is 0.5m long, and the electrode spacing is set to 10mm. The cathode is aligned with the inner surface of the fabric (skin layer), and the anode is aligned with the outer surface of the fabric (surface layer). A DC voltage of 50V is applied, and the fabric is subjected to the electric field for 2s.

[0053] S4. Asymmetric Thermophoretic Migration and Oriented Fixation: The wet fabric, after electrophoretic pre-separation, is immediately introduced into the asymmetric hot air unit for pre-drying. Parameter settings are as follows: (1) Outer surface (surface layer, anode side): hot air temperature 120℃, hot air vertical blowing speed 15m / s.

[0054] (2) Inner surface (skin layer, cathode side): hot air temperature 70℃, hot air vertical blowing speed 2m / s.

[0055] S5. High-temperature baking (cross-linking curing): The fabric, after asymmetric pre-drying, is then placed in the baking zone of a standard hot air tenter frame. The baking temperature is set at 150℃, and the baking time is 45 seconds. After baking, the fabric is cooled, unloaded, and wound up to obtain the finished product.

[0056] Example 3:

[0057] This embodiment provides a method for preparing a unidirectional moisture-wicking and quick-drying fabric, using a base fabric of 180g / m². 2 The polyethylene terephthalate pique mesh fabric includes the following steps: S1. Preparation of the working bath: Based on the amount of working solution per liter, first add 80% deionized water to the stirred tank, and start stirring. Then add the following in sequence: 1.5 g / L glacial acetic acid, 5 g / L of the composite stabilizer CS-3 prepared in Preparation Example 3, 60 g / L of anionic aqueous polyurethane dispersion, and 25 g / L of blocked polyisocyanate crosslinking agent. Stir for 10 min after each addition. Finally, add 50 g / L of cationic silicone microemulsion under slow stirring, and replenish the remaining deionized water. Stir for 15 min to obtain the mixed working solution. Adjust and confirm the pH of the working solution to 6.0.

[0058] S2. Fabric Padding: The base fabric is introduced into the finishing tank, and the working solution temperature is maintained at 30℃. The fabric adopts a two-stage padding process, with the padding machine speed set at 25m / min. The roller pressure is adjusted to control the liquid retention rate of the fabric after padding at 80%.

[0059] S3. Electrophoretic Migration Pre-Separation: The wet cloth after impregnation is immediately introduced into the DC electric field separation unit. The electrode plate of this unit is 1.5m long, and the electrode spacing is set to 30mm. The cathode is aligned with the inner surface of the fabric (skin layer), and the anode is aligned with the outer surface of the fabric (surface layer). A DC voltage of 200V is applied, and the fabric is subjected to the electric field for 3.6s.

[0060] S4. Asymmetric Thermophoretic Migration and Oriented Fixation: The wet fabric, after electrophoretic pre-separation, is immediately introduced into the asymmetric hot air unit for pre-drying. Parameter settings are as follows: (1) Outer surface (surface layer, anode side): hot air temperature 150℃, hot air vertical blowing speed 30m / s.

[0061] (2) Inner surface (skin layer, cathode side): hot air temperature 90℃, hot air vertical blowing speed 5m / s.

[0062] S5. High-temperature baking (cross-linking curing): The fabric, after asymmetric pre-drying, is then placed in the baking zone of a standard hot air tenter frame. The baking temperature is set at 170℃, and the baking time is 90 seconds. After baking, the fabric is cooled, unloaded, and wound up to obtain the finished product.

[0063] Comparative Examples 1-5: Comparative Example 1: Compared with Example 1, the difference is that step S3 is omitted, and the wet cloth after impregnation in step S2 is directly subjected to step S4. All other steps are the same as in Example 1.

[0064] Comparative Example 2: Compared with Example 1, the difference is that step S4 is changed to symmetrical hot air drying, that is, the hot air parameters for both the outer surface (surface layer) and the inner surface (skin-adhesive layer) are set as follows: hot air temperature 100°C, hot air vertical blowing speed 10m / s. All other steps are the same as in Example 1.

[0065] Comparative Example 3: Compared to Example 1, the difference lies in the following: a conventional two-step process is used, namely, the fabric is first treated and baked with the cationic silicone microemulsion (35 g / L) from step S1 of Example 1, and then the other side of the fabric is treated and baked with the anionic aqueous polyurethane dispersion (45 g / L), under the same baking conditions as step S5 of Example 1 (160°C, 60 s). All other steps are the same as in Example 1.

[0066] Comparative Example 4: The difference compared to Example 1 is that the base fabric does not use 160g / m². 2 Instead of using a plain knitted polyethylene terephthalate fabric, a double-knitted fabric with a polyethylene terephthalate inner layer and a cotton outer layer was selected, and steps S1, S3, S4, and S5 were not performed (i.e., no chemical finishing was done). All other steps were the same as in Example 1.

[0067] Comparative Example 5: Compared to Example 1, the difference lies in that: in step S1, the working bath contains only 35 g / L of cationic silicone microemulsion, 18 g / L of blocked polyisocyanate crosslinking agent, and 1.0 g / L of glacial acetic acid, without the addition of anionic aqueous polyurethane dispersion and composite stabilizer CS-1. All other steps are the same as in Example 1.

[0068] Test Examples 1-5: Experimental description: The liquid moisture management performance of fabrics was evaluated using a dynamic moisture transfer tester.

[0069] Sample preparation: The fabric samples obtained in Examples 1-3 and Comparative Examples 1-5, as well as a piece of unfinished base fabric (the same base fabric used in Example 1, serving as an equivalent reference for Comparative Example 4), were cut into 80mm × 80mm specimens, with 3 specimens per group. All specimens were conditioned under standard atmospheric conditions (temperature 20±2℃, relative humidity 65±5%) for at least 24 hours.

[0070] Test parameter settings: Test solution: 0.9% NaCl aqueous solution.

[0071] Drop volume: 0.2 mL.

[0072] Test duration: 120 seconds.

[0073] Test surface: Place the inner surface (skin-contact layer) of the fabric facing upwards on the lower sensor (simulated skin side) of the tester, and the outer surface (surface layer) facing downwards in contact with the upper sensor.

[0074] Test procedure: Place the conditioned sample between the sensors of the tester in the specified direction, ensuring that the fabric is flat and wrinkle-free; The test program is started, and the instrument automatically adds 0.2 mL of test solution to the center of the inner surface of the fabric; The instrument continuously monitors and records the resistance changes of the sensors on the upper and lower surfaces of the fabric within 120 seconds, and calculates the absorption, diffusion and transfer behavior of moisture based on this. Each group of samples is tested three times and the average value is taken.

[0075] The instrument automatically calculates the cumulative unidirectional moisture transfer index based on the dynamic changes in moisture content on the upper and lower surfaces. This index comprehensively reflects the fabric's ability to absorb moisture from the inner layer, transfer it to the outer layer, and diffuse it. The theoretical range is 0-1, with a higher value indicating better unidirectional moisture wicking performance.

[0076] The moisture content at the maximum wetting radius of the bottom (inner surface) or an equivalent reverse osmosis index. This index reflects the dryness of the skin-adhesive layer after the test; the lower the value, the better.

[0077] Experimental data: Table 1 Test data of unidirectional moisture wicking performance of different samples Sample number Cumulative one-way transmission index Moisture content (%) at the maximum wetting radius of the bottom surface Example 1 0.86 18.5 Example 2 0.79 22.1 Example 3 0.81 20.8 Comparative Example 1 0.23 65.3 Comparative Example 2 0.31 58.9 Comparative Example 3 0.65 35.4 Comparative Example 4 0.08 78.2 Comparative Example 5 0.12 71.6 in conclusion: The data in Table 1 show that the unidirectional moisture-wicking and quick-drying fabrics prepared by the method of the present invention (Examples 1-3) exhibit superior unidirectional moisture-wicking performance compared to the comparative examples.

[0078] The cumulative unidirectional transfer indices of Examples 1-3 were all higher than those of the comparative examples, with Example 1 reaching 0.86. Simultaneously, Example 1 exhibited the lowest bottom surface moisture content (18.5%), demonstrating its excellent ability to rapidly transfer moisture from the skin-adhesive layer to the outer layer while maintaining the inner layer's dryness. This is attributed to the unique active separation mechanism of this invention: The electrophoretic migration in step S3 utilizes the opposite migration characteristics of cationic hydrophobic agents and anionic hydrophilic agents in a DC electric field, achieving a preliminary and rapid concentration gradient distribution of the two functional auxiliaries in the fabric thickness direction. That is, cationic hydrophobic agents tend to accumulate in the outer layer (anode side), while anionic hydrophilic agents tend to accumulate in the inner layer (cathode side).

[0079] The asymmetric thermophoresis in step S4 utilizes the temperature gradient and evaporation rate difference generated by high-temperature, high-speed hot air (outer layer) and low-temperature, low-speed hot air (inner layer). This difference drives the further directional migration of moisture and dissolving / dispersing functional additives in the finishing solution: moisture preferentially evaporates from the high-temperature, high-speed outer layer, forming a concentration gradient and capillary migration flow from the inside out, which enhances the retention of hydrophilic agents in the inner layer and the migration and fixation of hydrophobic agents to the outer layer.

[0080] The high-temperature baking in step S5 ultimately permanently solidifies this functional gradient structure, which is synergistically constructed through electric and thermal fields, onto the fabric fibers through the action of a crosslinking agent, forming a stable internally hydrophilic and externally hydrophobic structure.

[0081] The cumulative unidirectional transfer index values ​​of Comparative Examples 1 and 2 decreased, indicating extremely high bottom surface moisture content. This confirms the crucial roles of electrophoretic pre-separation and asymmetric thermophoresis in constructing an effective functional gradient and achieving unidirectional moisture conduction. Without these two steps, anionic and cationic auxiliaries tend to mix randomly or distribute uniformly within the fabric, failing to form effective moisture-conducting channels.

[0082] Although Comparative Example 3 also constructed a functional layer, its cumulative unidirectional transfer index was lower than that of the Example, and its bottom surface moisture content was also higher. This may be because the two-step process is difficult to form a fine and continuous functional gradient interface at the fiber microscale as achieved by the one-step method of this invention, and multiple processing steps may damage the fibers or block some pores, affecting the efficient transfer of moisture.

[0083] The test data for Comparative Example 4 and Comparative Example 5 are as expected, with their cumulative unidirectional transmission index close to zero, indicating that they do not have unidirectional moisture-wicking function.

[0084] In summary, this invention, through a one-step process, can efficiently and stably construct an optimized functional gradient structure within the fabric, thereby endowing the fabric with excellent unidirectional moisture-wicking properties.

[0085] Test Example 2: Experimental description: The drying time of fabrics was determined using the heated plate method. This method simulates a heat source (such as skin) by providing constant heat and monitoring the time required for the fabric to evaporate moisture to a dry state.

[0086] Sample preparation: The fabric samples obtained in Examples 1-3 and Comparative Examples 1-5, as well as a piece of unfinished base fabric (the same base fabric used in Example 1, serving as an equivalent reference for Comparative Example 4), were cut into 100mm × 100mm specimens, with 3 specimens per group. All specimens were conditioned under standard atmospheric conditions for at least 24 hours.

[0087] Test parameter settings: Instrument: Fabric moisture evaporation rate tester (heating plate); Heating plate temperature: 37℃ (simulating human skin temperature); Environmental conditions: Temperature 20℃, relative humidity 65%, airflow velocity 1.0m / s; Drop volume: 0.2 mL (or a specified amount sufficient to wet the center of the fabric).

[0088] Test steps: Place the conditioned sample on the heating plate of the testing instrument, ensuring the fabric is flat; After the sample temperature stabilizes at 37°C, 0.2 mL of test solution (0.9% NaCl aqueous solution) is added to the center of the sample using an automatic dispensing device. The instrument immediately begins monitoring and recording the power consumption required to maintain a constant temperature of the heating plate, or continuously monitors the sample weight loss via a high-precision balance; The test automatically stops when the moisture has completely evaporated and the power required by the heating plate (or the sample weight) has returned to the initial stable state before the droplet was dropped.

[0089] Drying time: The time (in minutes) required from the start of dripping until all the water has evaporated. The shorter the time, the better the drying performance.

[0090] Experimental data: Table 2. Test data on drying time of different samples Sample number Drying time (min) Example 1 14.8 Example 2 16.9 Example 3 15.6 Comparative Example 1 24.3 Comparative Example 2 22.8 Comparative Example 3 20.5 Comparative Example 4 26.1 Comparative Example 5 9.7 in conclusion: Table 2 shows that the drying time of the samples in Examples 1-3 was shorter than that of Comparative Examples 1, 2 and 4.

[0091] Examples 1-3 exhibited high drying efficiency. The mechanism lies in the fact that when moisture comes into contact with the inner layer, the hydrophilic layer absorbs the moisture and transfers it to the outer layer using capillary effects and functional gradients. The hydrophobic structure of the outer layer promotes the spread of moisture on the fiber surface, forming a thin water film with increased surface area. The expansion of moisture on the outer surface of the fabric increases the vapor-liquid contact area, thereby achieving higher evaporation efficiency under the same environmental conditions, resulting in a shorter drying time.

[0092] Comparative Examples 1 and 2 failed to form an effective functional gradient, preventing moisture from being directionally transported to the outer surface and spread out. Moisture accumulated inside the fabric, resulting in a small vaporization area, slow evaporation, and prolonged drying time.

[0093] The drying time of Comparative Example 3 is longer than that of Example 1, indicating that the functional layer constructed in Comparative Example 3 has lower efficiency in moisture transfer and diffusion than the gradient structure formed by the one-step process of this invention.

[0094] Comparative Example 4 lacks proactive moisture management capabilities, relying on natural infiltration and evaporation for moisture, resulting in the lowest efficiency and longest drying time.

[0095] Comparative Example 5 had the shortest drying time (9.7 min). This data is not comparable. Test Example 1 has confirmed that the sample in Comparative Example 5 is water-repellent and does not have moisture-wicking properties. In the test, most of the 0.2 mL droplets remained on the fabric surface and were not absorbed. The measurement only measured the evaporation time of the surface droplets, which does not reflect the actual working conditions of rapid drying after moisture absorption.

[0096] In summary, this invention achieves a high evaporation rate and a short effective drying time by constructing moisture transfer and diffusion channels inside the fabric, allowing liquid water to spread over a large area on the outer surface.

[0097] Test Example 3: Experimental description: The ability of the example samples and comparative samples to retain their unidirectional moisture-wicking function after undergoing multiple cycles of washing was evaluated.

[0098] Sample preparation: Select the samples from Examples 1-3, and the Comparative Example 3 (conventional two-step method) sample with the closest unidirectional hygroscopic performance.

[0099] Washing program: It uses a standard upright front-loading washing machine to simulate home washing conditions (e.g., cotton fabric program, 40°C).

[0100] Use standard reference detergent, without adding any fabric softener or bleach.

[0101] Place the sample and the accompanying fabric into the washing machine and run a complete wash, rinse, and spin cycle.

[0102] After washing, the sample was removed and dried completely using a drum dryer.

[0103] Repeat steps 1-4 above for a total of 50 cycles.

[0104] Test process: Initial (0 washes) unidirectional moisture wicking performance data of the samples from Examples 1-3 and Comparative Example 3 were obtained (based on the method of Test Example 1). After 50 cycles of washing and drying, the sample was re-conditioned for at least 24 hours under standard atmospheric conditions (temperature 20±2℃, relative humidity 65±5%). After conditioning, the cumulative unidirectional transfer index was retested according to the experimental method of Test Example 1.

[0105] Cumulative One-Way Transfer Index (after washing): The cumulative one-way transfer index value measured after 50 washes.

[0106] Performance retention rate (%): (Post-wash index / Initial index) × 100%.

[0107] Experimental data: Table 3. Unidirectional hygroscopic performance data of different samples after 50 washes. Sample number Initial cumulative one-way transfer index Cumulative unidirectional transfer index after 50 washes Performance retention rate (%) Example 1 0.86 0.79 91.9 Example 2 0.79 0.68 86.1 Example 3 0.81 0.72 88.9 Comparative Example 3 0.65 0.29 44.6 in conclusion: Table 3 shows that the samples prepared in this invention, namely Examples 1-3, have better wash fastness than the sample in Comparative Example 3.

[0108] After 50 cycles of washing, the cumulative unidirectional transfer index performance retention rate of Examples 1-3 was all above 85%, with Example 1 having a retention rate of 91.9%, indicating that the functional structure of Example 1 was stable.

[0109] This fastness is attributed to the fixation mechanism of the one-step process of this invention: in the S5 high-temperature baking step, the blocked polyisocyanate crosslinking agent is deblocked by heat, and the released -NCO groups undergo a chemical crosslinking reaction with the fiber, the anionic aqueous polyurethane dispersion, and the cationic silicone microemulsion. During this crosslinking reaction, the functional gradient has already been constructed within the fabric through electrophoretic migration in S3 and asymmetric thermophoretic migration in S4. Therefore, the S5 step solidifies the already formed functional gradient structure in situ, forming an integrated crosslinked network chemically bonded to the fiber.

[0110] Comparative Example 3 showed a performance retention rate of 44.6%, with functionality diminishing after washing. This is because the two-step process involves two consecutive padding and baking cycles, resulting in the sequential mechanical attachment of the hydrophilic and hydrophobic layers. There is a lack of effective chemical bonding between these two functional additive layers. During the wet, mechanically abrasive washing process, the coating is prone to peeling and detachment, leading to the disruption of the functional gradient structure.

[0111] In summary, the present invention utilizes an electric and thermal field to create a gradient and a one-step high-temperature baking process to achieve integrated cross-linking and curing, resulting in a functional structure that is superior to traditional processes in terms of durability.

[0112] Test Example 4: Experimental description: A fabric air permeability tester was used to determine the ability of a fabric to transmit air, in order to assess the impact of finishing processes on fabric comfort.

[0113] Sample preparation: Select samples from Examples 1-3 and Comparative Example 3, as well as an untreated base fabric (the same base fabric used in Example 1, designated as Comparative Example 4). Cut 3 samples from each group. Condition all samples under standard atmospheric conditions (temperature 20±2℃, relative humidity 65±5%) for at least 24 hours.

[0114] Test parameter settings: Instrument: Automatic air permeability tester; Test area: 20cm 2 ; Pressure difference: 100 Pa (constant pressure); Test environment: Standard atmospheric conditions.

[0115] Test steps: The conditioned sample is held flat on the test head of the tester, ensuring a good seal and no air leakage. Start the instrument and set the differential pressure to 100 Pa; The instrument automatically adjusts the fan to maintain a constant pressure difference of 100 Pa across the sample and measures the airflow through the test area at this time. The instrument automatically calculates and displays the air permeability based on the airflow and the test area.

[0116] Air permeability: The airflow rate (mm / s) that passes vertically through a unit area of ​​fabric per unit time under a specified pressure difference.

[0117] Experimental data Table 4. Test data on air permeability of different samples Sample number Air permeability (mm / s) Example 1 1465 Example 2 1493 Example 3 1421 Comparative Example 3 946 Comparative Example 4 1512 in conclusion: Table 4 shows that the air permeability of samples 1-3 is close to that of the untreated base fabric, i.e., Comparative Example 4, while the air permeability of sample 3 is lower than that of the former two.

[0118] The air permeability of Examples 1-3 decreased only slightly compared to that of Comparative Example 4. This indicates that the process of the present invention has little impact on the original pore structure of the base fabric.

[0119] The mechanism lies in the active orientation effect of S3 and S4, which allows the anionic aqueous polyurethane dispersion and cationic silicone microemulsion to preferentially accumulate and fix in situ on the fiber surface, rather than accumulating in the pores of the fabric. The one-step baking and curing of S5 solidifies this functional coating along the fiber surface, maintaining the original open-cell structure of the fabric and thus preserving its breathability.

[0120] The air permeability of Comparative Example 3 was 946 mm / s, which was about 37.4% lower than that of Comparative Example 4 (1512 mm / s). This is because the conventional two-step process lacks an active orientation mechanism. During the two padding and two baking processes, the finishing solution accumulates, cross-links, and forms a film in the pores between the yarns, resulting in physical blockage of the fabric pores.

[0121] In summary, the one-step process of the present invention can impart functionality to the fabric while preserving the physical structure of the base fabric, avoiding the problem of reduced air permeability caused by pore blockage in conventional processes.

[0122] Test Example 5: Experimental description: The bending length of the fabric was determined using the inclined plane method (cantilever beam method). This index is used to characterize the stiffness of the fabric, thereby objectively evaluating the impact of finishing processes on the fabric's hand feel.

[0123] Sample preparation: Select samples from Example 1 and Comparative Example 3, as well as an untreated base fabric (the same base fabric used in Example 1, designated as Comparative Example 4). Cut 25mm × 200mm specimens along both the warp (longitudinal) and weft (transverse) directions, with 3 specimens in each group. Condition all specimens under standard atmospheric conditions for at least 24 hours.

[0124] Test parameter settings: Instrument: Fabric stiffness tester; Test principle: The sample is placed on a horizontal platform and slowly pushed out to form a cantilever beam. The length of the cantilever when the free end droops due to its own weight and contacts the 41.5° inclined plane is measured.

[0125] Test steps: Place the conditioned sample flat on the horizontal platform of the instrument, with its long side parallel to the slide rule; Start the motor or manually push the sample slowly and at a constant speed toward the edge of the platform; Stop immediately when the free end of the specimen just touches the 41.5° inclined plane; The length of the sample extending beyond the edge of the platform at this point is read from the slide ruler; this is half the bending length. Multiply the reading by 2 to obtain the bending length (mm) of the sample; Test the bending lengths in the longitudinal and latitudinal directions separately, and calculate the average value.

[0126] Key metrics: Bending length (mm): The ability of a fabric to resist bending deformation. The longer the bending length, the stiffer the fabric; conversely, the shorter the bending length, the softer the fabric.

[0127] Experimental data: Table 5. Test data on stiffness of different fabric samples Sample number Meridional bending length (mm) Length of latitudinal bend (mm) Example 1 32.7 28.3 Comparative Example 3 48.9 44.6 Comparative Example 4 28.5 25.1 in conclusion: Table 5 shows that the fabric of Example 1 treated with the process of the present invention has a higher bending length than the untreated base fabric, i.e., Comparative Example 4. The fabric of Comparative Example 3, treated with the conventional two-step method, has an even higher increase in bending length.

[0128] The increase in warp and weft bending length in Example 1 is smaller than that in Comparative Example 4, indicating that the process of the present invention can better maintain the original softness of the base fabric while imparting functionality.

[0129] The mechanism lies in the fact that the one-step process of this invention has a short flow, and the fabric undergoes only one heat treatment. The active orientation effect of S3 electrophoretic migration and S4 asymmetric thermophoretic migration causes the functional finishing agent to preferentially form a thin functional coating on the fiber surface, rather than causing large-scale aggregation and excessive cross-linking at the yarn-to-yarn junctions. This allows the yarns and fibers in the fabric to maintain relative freedom of movement, thereby maintaining the overall low bending stiffness of the fabric.

[0130] The bending length of Comparative Example 3 increased, and the fabric hand feel hardened. This is because the process in Comparative Example 3 involved two padding processes and two high-temperature baking processes. In the absence of an active orientation mechanism, film-forming substances and crosslinking agents in the finishing solution are more likely to accumulate at the pores where the yarns meet. After two high-temperature treatments, these accumulations form rigid connection points at the meeting points, restricting the relative positions of the yarns and resulting in an increase in the bending stiffness of the fabric.

[0131] In summary, this invention avoids the fabric hardening problem caused by excessive cross-linking of finishing agents in the yarn gaps in conventional processes by performing in-situ functionalization on the fiber surface.

Claims

1. A method for preparing a unidirectional moisture-wicking and quick-drying fabric, characterized in that, Includes the following steps: S1. Add anionic aqueous polyurethane dispersion, cationic silicone microemulsion, composite stabilizer, blocked polyisocyanate crosslinking agent and glacial acetic acid to deionized water, stir and mix to obtain finishing working solution; S2. The base fabric is impregnated and rolled in the finishing solution to obtain a wet fabric; S3. The wet cloth is introduced into a DC electric field, with the cathode corresponding to the inner surface of the fabric and the anode corresponding to the outer surface of the fabric. The anionic aqueous polyurethane dispersion is enriched on the inner surface of the fabric and the cationic organosilicon microemulsion is enriched on the outer surface of the fabric by the electric field, thus obtaining a pre-separated wet cloth. S4. Apply high-temperature, high-speed hot air to the outer surface of the pre-separated wet cloth, and simultaneously apply low-temperature, low-speed hot air to the inner surface of the pre-separated wet cloth to obtain a pre-dried fabric. S5. The pre-dried fabric is baked at high temperature to obtain a one-way moisture-wicking quick-drying fabric.

2. The method for preparing a unidirectional moisture-wicking and quick-drying fabric according to claim 1, characterized in that, The composite stabilizer is formulated from a nonionic surfactant and an amphoteric surfactant, and the preparation steps of the composite stabilizer include: Heat the deionized water to the preset temperature; The nonionic surfactant is added to the deionized water under stirring, and the mixture is stirred until completely dissolved. Continue adding the amphoteric surfactant while stirring and at the preset temperature, stirring until the system is uniformly mixed; Stop heating and cool to room temperature to obtain the composite stabilizer.

3. The method for preparing a unidirectional moisture-wicking and quick-drying fabric according to claim 2, characterized in that, In the preparation steps of the composite stabilizer, the preset temperature is 40-60℃; After adding the nonionic surfactant, the stirring time is 15 to 20 minutes; After adding the amphoteric surfactant, continue stirring for 30 to 45 minutes.

4. The method for preparing a unidirectional moisture-wicking and quick-drying fabric according to claim 2, characterized in that, The nonionic surfactant is specifically fatty alcohol polyoxyethylene ether or octylphenol polyoxyethylene ether. The amphoteric surfactant is specifically dodecyl dimethyl betaine or cocamidopropyl betaine.

5. The method for preparing a unidirectional moisture-wicking and quick-drying fabric according to claim 1, characterized in that, In step S1, the amount of each component used per liter of the finishing working solution is as follows: The anionic aqueous polyurethane dispersion: 30-60g; The cationic organosilicon microemulsion: 20-50g; The composite stabilizer: 2-5g; The blocked polyisocyanate crosslinking agent: 10-25g; The glacial acetic acid: 0.5–1.5 g; The pH value of the finishing working solution is 5.0 to 6.

0.

6. The method for preparing a unidirectional moisture-wicking and quick-drying fabric according to claim 1, characterized in that, In step S2, the base fabric is specifically polyethylene terephthalate fabric.

7. The method for preparing a unidirectional moisture-wicking and quick-drying fabric according to claim 1, characterized in that, In step S2, the liquid retention rate of the base fabric after impregnation is controlled to be 70% to 80%.

8. The method for preparing a unidirectional moisture-wicking and quick-drying fabric according to claim 1, characterized in that, In step S3, the applied DC voltage is 50–200V, the electrode spacing is 10–30mm, and the fabric is subjected to the electric field for 2–3.6s.

9. The method for preparing a unidirectional moisture-wicking and quick-drying fabric according to claim 1, characterized in that, In step S4, the temperature of the high-temperature high-speed hot air is 120-150℃ and the wind speed is 15-30m / s; the temperature of the low-temperature low-speed hot air is 70-90℃ and the wind speed is 2-5m / s.

10. The method for preparing a unidirectional moisture-wicking and quick-drying fabric according to claim 1, characterized in that, In step S5, the baking temperature is 150–170°C and the baking time is 45–90 seconds.