Wool blended fabric and preparation method thereof

Abstract

The present invention discloses a method for preparing a wool blended fabric, which relates to the technical field of textile composite materials. The method first uses a water jet loom to weave a functional supporting bottom layer containing carbon fiber conductive yarns, uses a rapier loom to prepare a wool blended surface layer, and uses a pretreatment liquid containing hydrogen peroxide, chitosan and acetic acid to steam-treat the surface to selectively modify the edges of the scales; then, a diamond grid array is dispensed on the surface of the PU-based composite film and through micropores are prefabricated; the above three-layer structure is stacked and then hot-pressed and rapidly cooled for solidification; finally, a fluorine-containing water repellent is applied to each area and a high-voltage electric field is applied for treatment. The present invention uses a chitosan cationic film to cover the scale grooves and hydrogen peroxide for targeted oxidation, which fundamentally reduces the difference in fiber forward and reverse friction and avoids strong damage; the dispensing structure uses an inclined diamond grid and micropores to decouple the branched anchoring network formed by capillary climbing from the moisture permeability channel, breaking through the technical bottleneck that it is difficult to balance anchoring strength and moisture permeability efficiency in traditional processes.

Description

Technical Field

[0001] The invention belongs to the technical field of textile composite materials, and particularly relates to a wool blended fabric and a preparation method thereof. Background Art

[0002] With the continuous upgrading of the demand for multifunctional fabrics in the outdoor sportswear market, blended fabrics that combine the touch of natural wool and the functionality of synthetic fibers have become a research and development hotspot; especially in the field of extreme climate protection, users require fabrics to maintain the inherent moisture absorption, breathability and warmth retention properties of wool, and also need to integrate composite functions such as waterproof and breathable, anti-static, and high-strength support. Traditional single-layer wool fabrics are difficult to meet high-performance application scenarios due to insufficient mechanical strength and easy shrinkage defects, which drives the industry to transform to multi-layer composite structures.

[0003] The current mainstream process adopts a layered composite strategy, introducing a polyurethane adhesive layer between the wool blend surface layer and the functional bottom layer, and achieving integration through hot pressing. One representative solution is to pre-treat the wool blend layer with acid chlorination to inhibit shrinkage. For example, it is immersed in a pH 4.0 treatment solution containing 3.0g / L sodium hypochlorite, and the strong oxidizing property is used to destroy the disulfide bonds on the surface of the scales to reduce the directional friction effect. Although this method can reduce the washing shrinkage rate to 0.038%, the atomic oxygen generated by hypochlorous acid in an acidic environment indiscriminately attacks the peptide bonds of wool, causing hydrolysis and breakage of the fiber body. At the same time, the residual chloride ions cause the risk of skin sensitization. Another technical bottleneck lies in the adhesive layer. To improve the bonding strength between layers, the conventional dispensing process uses full coverage hot melt adhesive, but it completely blocks the moisture permeability channel, causing water vapor to dissolve and diffuse through the polyurethane membrane, and the moisture permeability rate is significantly reduced compared to the gas phase diffusion mechanism.

[0004] Therefore, there is an urgent need to develop a composite fabric preparation method that can accurately control the friction properties of the scales while retaining the strength of the wool fiber itself, and synergistically achieve high anchoring strength and moisture permeability. Summary of the Invention

[0005] The present invention overcomes the deficiencies of the prior art and provides a wool blended fabric and a preparation method thereof.

[0006] To achieve the above object, the technical solution adopted by the present invention is: a method for preparing a wool blended fabric, comprising the following steps:

[0007] Step 1: Prepare a functional support base layer;

[0008] Step 2: Preparing a wool blended surface layer and pre-treating it; the pre-treatment comprises immersing the wool blended surface layer in a treatment solution comprising hydrogen peroxide, chitosan, and acetic acid, followed by saturated steam treatment to modify the edges of the wool scales; the treatment solution comprises 1.2-1.8 g / L hydrogen peroxide, 1.3-1.7 g / L chitosan with a deacetylation degree of 85%, and 0.7-0.9 g / L acetic acid;

[0009] Step 3: preparing a PU-based composite film and performing a glue dispensing process; the glue dispensing process includes applying a hot-melt polyurethane adhesive on the surface of the PU-based composite film to form glue dots arranged in a diamond grid array with a coverage rate of 50-70%, and prefabricating a through micropore at the center of each glue dot;

[0010] Step 4: stacking the functional support bottom layer, the PU-based composite film after the glue treatment, and the pre-treated wool blended surface layer in sequence, and hot pressing and laminating to obtain a composite fabric;

[0011] Step 5: Post-process the composite fabric.

[0012] Furthermore, the preparation process of the functional support bottom layer includes using a water jet loom to weave 90% to 94% by mass of fine denier nylon filaments and 6% to 10% by mass of carbon fiber conductive yarns in a plain weave, controlling the warp density to 210-230 strands / inch and the weft density to 170-190 strands / inch, forming a grammage of 115-125g / m 2 functional support base.

[0013] Furthermore, the saturated steam treatment includes controlling the rolling margin to 75%-85% and maintaining the temperature at 100-104° C. for 2.5-3.5 minutes.

[0014] Furthermore, the preparation process of the wool blended surface layer includes using a rapier loom to weave a blended yarn of 52% to 58% by mass of fine wool fiber, 33% to 37% by mass of hollow polyester staple fiber and 8% to 12% by mass of elastic filament in a 2 / 2 twill weave, controlling the warp density to 170-190 strands / inch and the weft density to 150-170 strands / inch, forming a gram weight of 115-125g / m 2 Wool blend upper.

[0015] Furthermore, the dispensing process uses a hot melt polyurethane adhesive with a melt index of 115-125g / 10min;

[0016] The diameter of the glue dots formed is 0.28-0.32mm;

[0017] The diameter of the through micropores is 48-52 μm.

[0018] Furthermore, the preparation process of the PU-based composite film includes melt-blending a polyether polyurethane resin with a mass fraction of 87.5-88.5% and a thermoplastic polyurethane elastomer microparticles with a mass fraction of 11.5-12.5% ​​through a twin-screw extruder, and casting the resulting mixture into a PU-based composite film with a thickness of 0.024-0.026 mm at a melt temperature of 185-190°C and a screw speed of 120-150 rpm.

[0019] Furthermore, the hot pressing compounding includes laminating at a temperature of 145-155° C., a pressure of 0.65-0.75 MPa, and a line speed of 2.4-2.6 m / min.

[0020] Furthermore, the post-treatment includes immersing the composite fabric in a C6 fluorine-containing water repellent working solution with a mass concentration of 28-32 g / L, controlling the rolling rate to 70%-75%, and then subjecting the composite fabric to a hot air circulation setting treatment at 168-172°C for 55-65 seconds.

[0021] Furthermore, the post-processing includes applying a 4.8-5.2 kV high voltage electric field to the functional support bottom layer and maintaining a directional discharge for 28-32 seconds under a nitrogen protective atmosphere.

[0022] Another technical solution provided by the present invention is a wool blended fabric prepared based on the above preparation method.

[0023] The present invention solves the defects existing in the background technology and has the following beneficial effects:

[0024] The wool blended surface layer is subjected to saturated steam treatment using a pretreatment solution containing 1.2-1.8g / L hydrogen peroxide, 85% deacetylated chitosan, and 0.7-0.9g / L acetic acid. The protonation degree of the chitosan molecular chain amino group reaches a peak in the pH range of 5.4-5.6, and the cationic polymer is directional adsorbed on the negatively charged cystine residue surface of the wool scales by electrostatic attraction to form a continuous film. At the same time, hydrogen peroxide, driven by steam thermodynamics, selectively penetrates to the edge of the scales, preferentially breaking the disulfide-rich keratin to generate hydrophilic sulfonic acid groups. The chitosan film covers the stepped grooves of the scales, converting inter-fiber slippage into low-friction motion of the film layer. This process fundamentally suppresses the friction difference between the wool fiber's forward and reverse scales, reduces the directional friction coefficient, and reduces the risk of hydrolysis and breakage of the fiber body compared to the traditional strong acid chlorination treatment process. The present invention avoids excessive fiber strength loss leading to failure. Furthermore, the surface energy of the fiber is reduced after pretreatment, creating a low-energy barrier interface for subsequent colloid wetting, synergistically improving the interlayer bonding strength.

[0025] Based on a glue processing structure arranged in a diamond grid array with a coverage rate of 50-70%, each glue point has a prefabricated through-hole in the center. When the external force transmission path is inclined at 45° to the warp and weft directions of the fabric, the in-plane shear stress is vector-decomposed into a composite load of normal compression and tangential tension. At the same time, the viscosity of the hot-melt polyurethane glue drops sharply during the hot pressing stage, resulting in capillary climbing, forming a dendritic penetration network along the microgrooves on the surface of the wool fiber. Its main channel wraps the fiber bundle contact points through mechanical biting, so that the glue point penetration depth reaches 55%-65% of the fiber layer thickness. Compared with the defect of traditional full-coverage glue coating process that blocks the microporous channel, the present invention maintains the microporous channel diameter at more than 5 times the kinetic diameter of water vapor molecules, ensuring that the water vapor diffusion flux is greater than 2600g / m 2 / 24h; while liquid water is blocked outside due to the limited curvature radius of the meniscus, breaking through the technical contradiction of high anchoring strength and moisture permeability.

[0026] In the PU-based composite film, 11.5-12.5% ​​by mass of TPU microparticles and 87.5-88.5% of polyether polyurethane resin are melt-blended in a twin-screw extruder. At a melt temperature of 185-190°C, the shear field intensity breaks the TPU microparticles. The temperature difference during casting and rapid cooling induces crystallization of the PU hard segment microdomains while the TPU microparticles remain amorphous, constructing a viscoelastic network with controllable molecular chain entanglement point density. When the hot pressing temperature exceeds the glass transition threshold of the adhesive, the differential deformation of the modulus between the TPU microparticles and the PU matrix triggers forced high-elastic deformation. Mechanical energy is converted into thermal energy through intramolecular friction, further coupling the diamond grid framework of the adhesive point unit. Under the action of external force, the molten colloid is spatially constrained by the grid nodes when climbing along the wool fiber grooves, thereby improving the uniformity of the anchoring depth. The simultaneous rapid cooling triggers an ultrafast phase transition of the colloid, and the molten polyurethane directly transitions to a highly crystalline state. The radial stress generated by volume shrinkage doubles the binding energy of the colloid-fiber interface, significantly inhibiting interfacial slip under water washing stress. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments described in the present invention. Those skilled in the art can also derive other drawings based on these drawings without inventive efforts.

[0028] Figure 1 The present invention is a flow chart of a method for preparing a wool blended fabric. DETAILED DESCRIPTION

[0029] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0030] In the following description, many specific details are set forth to facilitate a full understanding of the present invention. However, the present invention may also be implemented in other ways different from those described herein. Therefore, the scope of protection of the present invention is not limited to the specific embodiments disclosed below.

[0031] Unless otherwise specified, all raw materials described below are commercially available or prepared by conventional methods in the art. Fine-denier nylon filament (Amilan CM3001-N) and carbon fiber conductive yarn (Torayca T300-1K) were purchased from Toray; fine wool fiber (AOYU 001) was purchased from AOYU Cashmere; hollow polyester staple fiber (Toyobo® HollowPolyester) was purchased from Teijin Limited; elastic filament (Creora® 40D Spandex) was purchased from Hyosung; C6 fluorinated water repellent (environmentally friendly C6 fluorinated fabric finishing agent) was purchased from Shangchen Chemical; thermoplastic polyurethane elastomer microparticles (TPU microparticles), polyether polyurethane resin, hot-melt polyurethane adhesive (TPU hot-melt adhesive), and chitosan (85% deacetylation degree) were all purchased from Sinopharm and were of analytical grade.

[0032] Exemplary methods:

[0033] like Figure 1 As shown, a method for preparing a wool blended fabric comprises the following steps:

[0034] Step 1: Prepare a functional support base layer;

[0035] Step 2: Preparing a wool blended surface layer and pre-treating it; the pre-treatment comprises immersing the wool blended surface layer in a treatment solution comprising hydrogen peroxide, chitosan, and acetic acid, followed by saturated steam treatment to modify the edges of the wool scales; the treatment solution comprises 1.2-1.8 g / L hydrogen peroxide, 1.3-1.7 g / L chitosan with a deacetylation degree of 85%, and 0.7-0.9 g / L acetic acid;

[0036] Step 3: preparing a PU-based composite film and performing a glue dispensing process; the glue dispensing process includes applying a hot-melt polyurethane adhesive on the surface of the PU-based composite film to form glue dots arranged in a diamond grid array with a coverage rate of 50-70%, and prefabricating a through micropore at the center of each glue dot;

[0037] Step 4: stacking the functional support bottom layer, the PU-based composite film after the glue treatment, and the pre-treated wool blended surface layer in sequence, and hot pressing and laminating to obtain a composite fabric;

[0038] Step 5: Post-process the composite fabric.

[0039] Below, each step will be described in detail.

[0040] Step 1: Construct a basic carrier with a continuous conductive network and high-strength mechanical support properties to provide a dimensionally stable functional base layer for subsequent multi-layer composites. The specific implementation process includes using a water jet loom to weave 90% to 94% fine denier nylon filaments and 6% to 10% carbon fiber conductive yarns in a plain weave. By setting the process parameters of warp density of 210-230 strands / inch and weft density of 170-190 strands / inch, the weight is controlled at 115-125g / m 2 The functional support base of the interval.

[0041] The high-density plain weave compresses the interweaving angle of the warp and weft yarns, forcing the carbon fiber conductive yarns to embed into the weft yarn gaps of the fine-denier nylon filaments. This mechanical interlocking effect forms a three-dimensional topological structure. Its essence is that the accumulated normal pressure between the yarns enables the fabric to reach a high breaking strength level, and the specific reeding process guides the carbon fiber conductive yarns to establish a penetrating conductive path along the thickness of the fabric. In this process, the fluctuation of the warp yarn tension is controlled to prevent the high modulus carbon fiber from brittle fracture due to the concentration of bending stress. At the same time, the weft density adjustment mechanism dynamically compensates for the variation of yarn diameter to ensure the spatial continuity of the conductive network.

[0042] When the water jet loom drives the weft yarn to pass through the warp yarn opening, the fine denier nylon filaments produce radial elastic deformation at the interweaving points, and their restoring force forms a circumferential constraint on the carbon fiber conductive yarn; the carbon fiber conductive yarn resists the morphological distortion caused by weaving tension by virtue of its high tensile modulus, and under the condition that the distance between adjacent interweaving points is shortened, the electronic transition channel is overlapped through the dual effects of van der Waals force and mechanical bite.

[0043] The second step is to retain the natural touch and elasticity of wool through the textile structure, while using mild chemical treatment to improve the friction difference between the fiber scales at the molecular level, creating low-stress interface conditions for subsequent composite processes.

[0044] In this step, a rapier loom is used to weave a blended yarn of 52% to 58% fine wool fiber, 33% to 37% hollow polyester staple fiber and 8% to 12% elastic filament in a 2 / 2 twill structure, and the warp density is synchronously controlled to be 170-190 strands / inch and the weft density is 150-170 strands / inch, forming a gram weight of 115-125g / m 2The wool blended surface layer is chemically pretreated immediately after weaving. The wool blended surface layer is immersed in a treatment solution containing 1.2-1.8g / L hydrogen peroxide, 1.3-1.7g / L chitosan with a deacetylation degree of 85%, and 0.7-0.9g / L acetic acid. After the residual rate is controlled at 75%-85%, it is transferred to a saturated steam environment and treated at a temperature of 100-104℃ for 2.5-3.5 minutes.

[0045] In the 2 / 2 twill weave, the higher warp density conditions force the interweaving frequency of warp and weft yarns to increase significantly. The optimization of the yarn buckling shape enhances the bonding effect between fibers, directly inhibiting the physical tendency of the fiber ends to be pulled out of the yarn body. The hollow polyester staple fiber forms a micro-cushion structure in the twill floating length area, and its cavity cross-section blocks the direct friction of external forces on the wool scales through the buffering effect. The elastic filament serves as a covering component to maintain the geometric stability of the yarn and offset the grain distortion caused by weaving tension.

[0046] During the chemical pretreatment stage, when acetic acid adjusts the treatment solution to a pH range of 5.4-5.6, the protonation degree of the chitosan molecular chain amino group reaches a peak, and the cationic polymer is directionally adsorbed on the negatively charged cystine residue surface of the wool scales by electrostatic attraction; hydrogen peroxide selectively penetrates to the edge of the scales under the thermodynamic drive of steam, and preferentially undergoes oxidative chain cleavage with keratin rich in disulfide bonds.

[0047] Furthermore, the chitosan cationic film covers the micron-sized grooves on the stepped edges of the scales, converting the slip of the fiber body into low-friction slip between the film layers, fundamentally inhibiting the shrinkage dynamics; the steam condensation water film acts as a reaction medium carrier, prompting hydrogen peroxide to diffuse into the gaps between the scales, breaking the disulfide bonds of the edge keratin and converting them into hydrophilic sulfonic acid groups, while the main body of the scales only undergoes surface etching due to the high cross-linking density, avoiding damage to the fiber body strength; the rolling rate is set according to the fiber absorption saturation critical value to ensure full surface coverage of the solution while preventing solute enrichment due to capillary effect; the gradient temperature rise quickly penetrates the fiber surface air film in the initial stage, and the subsequent isothermal state maintains the reaction uniformity, and the online pH dynamic compensation ensures the stability of the chitosan dissolution kinetics.

[0048] Step three is to construct an interface layer with stress buffering and moisture permeability functions to achieve geometric anchoring structure and material dissipation characteristics, including the manufacture of PU-based composite film substrate and surface dispensing modification.

[0049] The manufacturing of PU-based composite film substrate includes blending and plasticizing thermoplastic polyurethane (TPU) particles and polyether polyurethane (PU) resin in a mass ratio of 11.5-12.5%:87.5-88.5% in a twin-screw extruder, controlling the melt temperature at 185-190°C and the screw speed at 120-150rpm to achieve molecular-level dispersion; the molten blend is extruded onto a mirror roller through a T-die, and is cast into a continuous film with a thickness of 0.024-0.026mm at a roller temperature of 65-70°C and a pulling speed of 3.0-3.5m / min. The film is then cooled in a cooling zone at 25±2°C to complete phase separation and curing, forming a composite structure in which TPU particles are evenly embedded in the PU matrix.

[0050] Surface dispensing modification involves applying a hot-melt polyurethane adhesive with a melt index of 115-125g / 10min to the membrane surface using a high-precision CNC dispensing machine. The diameter of the adhesive dots is adjusted to 0.28-0.32mm by matching the air pressure control system with the inner diameter of the needle, and arranged in a diamond grid array to control the coverage rate to 50-70%. A through micropore with a diameter of 48-52μm is preformed in the center of each adhesive dot using a UV laser ablation process.

[0051] The shear field intensity of the twin-screw extruder breaks the TPU particles into submicron-sized particles. The melt undergoes tensile flow orientation at the die lip exit, resulting in the formation of an island structure between the TPU-rich phase and the PU continuous phase. The sudden cooling temperature difference during the casting stage induces crystallization of the PU hard segment micro-domains, while the TPU particles remain amorphous due to the difference in glass transition temperature, constructing a viscoelastic network with a controllable density of molecular chain entanglement points. The 45° inclination of the diamond grid in the dispensing process causes the external force transmission path to be misaligned with the warp and weft directions of the fabric, converting the in-plane shear stress into a composite load of normal compression and tangential tension through vector decomposition. Laser ablation is performed before the glue point solidifies. The pulsed laser causes the surface molecular chains of the polyurethane glue to photothermally dissociate. The resulting micropore walls produce a hydrophobic and smooth surface due to the melt recasting effect, blocking the reverse osmosis of liquid caused by capillary phenomena.

[0052] In this step, when the PU-based composite film is softened by heat during the hot pressing stage, the TPU particles and the PU matrix produce modulus difference deformation, and the stress field around the particles triggers forced high-elastic deformation of the PU molecular chain, converting mechanical energy into thermal energy through intramolecular friction; the diamond array of the glue dot units forms a topological interlocking framework, and when the molten colloid climbs along the grooves on the wool fiber surface, its branched penetration path is constrained by the grid node space, ensuring the uniformity of the anchoring depth; the diameter design of the microporous channel is based on the multiple relationship between the kinetic diameter of water vapor molecules and the mean free path, maintaining the gas diffusion flux while blocking the penetration of liquid water.

[0053] Step 4: Establish an interlayer stress transfer channel and realize the integration of wool blended surface layer, PU-based composite film and functional support bottom layer through melt anchoring and phase change locking.

[0054] In this step, the functional support base layer, PU-based composite film (with the adhesive surface facing the wool blended surface layer), and pre-treated wool blended surface layer are stacked in this order. A laser alignment system is used to ensure that the arrangement direction of the underlying carbon fiber conductive filaments is parallel to the machine's travel axis, eliminating the risk of conductive network breakage caused by interlayer misalignment. The stacked functional support base layer, PU-based composite film, and pre-treated wool blended surface layer are fed into a double-roll hot press for continuous lamination. Dynamic hot pressing is performed at a temperature of 145-155°C, a pressure of 0.65-0.75MPa, and a line speed of 2.4-2.6m / min. After hot pressing, the material is immediately passed through a 20±2°C metal cooling roller for rapid curing, with a controlled cooling rate of 80-100°C / second.

[0055] When the hot-pressing temperature exceeds the glass transition threshold of the polyurethane adhesive, the viscosity of the molten colloid drops sharply, generating a capillary climbing effect. The adhesive forms a three-dimensional dendritic permeation network along the microgrooves and interfiber gaps on the wool fiber surface. Its main channel mechanically wraps around the contact points of adjacent fiber bundles. The oblique pressure component drives the adhesive point units to break through the surface energy barrier of the wool blend surface layer, penetrating to a depth of 55%-65% of the fiber layer thickness, forming a spatial anchoring node array. The rapid cooling process triggers an ultrafast phase transition of the colloid, directly transitioning the molten polyurethane to a highly crystalline state. The radial stress generated by the volume shrinkage significantly increases the colloid-fiber interface bonding energy. Simultaneously, under the rapid cooling conditions, the TPU particles in the PU-based composite film form a phase-separated structure with cross-linked hard segment microdomains, while the soft segment molecular chain conformation freezes to form a viscoelastic dissipative network.

[0056] In this step, the hot pressing parameters (temperature / pressure / speed) are linked and adjusted through the PID closed-loop system. The temperature sensor provides real-time feedback of the thermal field distribution on the membrane surface, and the thermal oil flow rate dynamically compensates for the ±2°C deviation. The cooling water circulation system maintains a temperature control accuracy of ±0.5°C to avoid uneven shrinkage stress caused by temperature gradients. Laser alignment not only ensures the continuity of the conductive network, but also enables the warp and weft yarns of the functional support bottom layer to form an optimal force angle with the hot pressing direction. The high-strength support function is retained at a rate of more than 98% after compounding. The spreading depth of the molten colloid on the wool fiber surface is controlled by the difference between the fiber surface energy and the colloid surface tension, spontaneously forming a tight interface with a wetting angle of less than 10°.

[0057] Step five simultaneously constructs a durable liquid-repellent barrier on the surface and an electrostatic dissipation path on the bottom layer, balancing protective performance and wearing comfort through a zoning treatment strategy. Post-processing includes overall water-repellent finishing and directional electrostatic optimization.

[0058] In this step, the composite fabric is first immersed in a C6 fluorine-containing water repellent working solution with a mass concentration of 28-32g / L, and the rolling rate is controlled to 70%-75% after which it is subjected to a hot air circulation setting treatment at 168-172°C for 55-65 seconds; then a 4.8-5.2kV high-voltage electric field is applied to the functional support bottom layer alone, and a directional discharge is maintained for 28-32 seconds under a nitrogen protective atmosphere (flow rate 3-5L / min), finally obtaining a functional fabric with both anti-pollution and antistatic properties.

[0059] In the initial stage of hot air setting, a gradient temperature rise process is used to quickly break through the migration energy barrier of the fluorinated water repellent, prompting the C6 fluorocarbon chain segments to be radially oriented at the gas-liquid interface; its perfluorohexyl side chains form a dense molecular array on the surface of the wool blended surface layer, while the polyoxyethylene blocks achieve chemical bonding through hydroxyl anchoring, synergistically establishing a low surface energy monolayer. In the high-voltage electric field treatment stage, the plasma generated by the ionized air between the electrodes bombards the surface of the carbon fiber conductive filaments, stripping off the adsorbed impurity layer and exposing the sp 2 Hybrid lattice defects; the nitrogen environment inhibits oxidation side reactions, and the distance between adjacent carbon fibers is reduced to submicron level under the action of Coulomb attraction, establishing a quantum tunneling conductive path through the electron cloud overlap effect.

[0060] In this step, the temperature of the water-repellent working liquid is constantly controlled to avoid the aggregation of fluorocarbon chain micelles. The rapid temperature rise in the initial stage of the gradient heating destroys the entanglement energy barrier of the molecular chain, and the subsequent isothermal stage enables the fluorocarbon chain to complete the orientation rearrangement; nitrogen protection not only blocks the generation of ozone, but also maintains the stability of plasma discharge. The directional electron flow selectively etches the amide bonds on the surface of the nylon filament to generate polar groups to enhance the electrical coupling between the carbon fiber and the nylon interface; the through micropores of the diamond grid glue dot units remain open channels after water-repellent treatment, and their pore size is much larger than the kinetic diameter of water vapor molecules and smaller than the curvature radius of the liquid water meniscus, realizing the dual functions of moisture permeability and liquid resistance.

[0061] Example products:

[0062] A wool blended fabric is prepared based on the above exemplary method.

[0063] Example 1:

[0064] A wool blended fabric is prepared by the following steps:

[0065] Step 1: Use a water jet loom to weave 92% of the mass fraction of m2 fine denier nylon filaments and 8% of the mass fraction of 0.1mm diameter carbon fiber conductive yarn in plain weave, control the warp density to 220 strands / inch and the weft density to 180 strands / inch, and make a gram weight of 120g / m 2 Functional support base.

[0066] Step 2: Use a rapier loom to weave 55% of 18.5μm Merino wool fiber, 35% of 0.8dtex hollow polyester staple fiber and 10% of 40D spandex elastic filament blended yarn in a 2 / 2 twill structure, setting the warp density to 180 strands / inch and the weft density to 160 strands / inch, resulting in a weight of 120g / m 2 Wool blended surface layer; the wool blended surface layer is immersed in a treatment solution containing 1.0 g / L hydrogen peroxide, 1.5 g / L chitosan with a deacetylation degree of 85%, and 0.8 g / L acetic acid, the rolling rate is set to 80% to achieve sufficient infiltration of the fiber gaps, and is treated with saturated steam at 102°C for 3 minutes.

[0067] Step 3: Melt-blend 88% of polyether polyurethane resin and 12% of TPU particles by mass through a twin-screw extruder, and cast into a 0.025mm thick film at a temperature gradient of 160-180°C and a screw speed of 200r / min; then use a CNC dispensing machine to apply a hot-melt polyurethane adhesive with a melt index of 120g / 10min on the film surface to form an anchoring unit with a glue point diameter of 0.30mm and a diamond grid array arrangement. The glue point coverage is controlled to 50% and a 50μm diameter through-hole is prefabricated in the center. The line connecting adjacent glue points is at a 45° angle to the warp and weft directions of the fabric.

[0068] Step 4: Assemble the functional support base layer, PU-based composite film (with the adhesive surface facing the wool blended surface layer), and wool blended surface layer in order, and perform hot pressing and lamination on a double-roll hot press at a temperature of 150°C and a pressure of 0.65 MPa at a line speed of 2.5 m / min; immediately pass through a 20°C metal cooling roller for rapid curing after the hot pressing and lamination is completed.

[0069] Step 5: Immerse the composite fabric in a C6 fluorine-containing water repellent working solution with a mass concentration of 30g / L, with a rolling rate of 70%, and then shape it through a 170°C hot air circulation for 60 seconds; apply a 5kV high-voltage electric field to the functional support bottom layer alone, and directionally discharge it for 30 seconds under a nitrogen protective atmosphere.

[0070] Example 2:

[0071] The difference from Example 1 is that the treatment liquid in step 2 of this example contains 1.5 g / L hydrogen peroxide, 1.5 g / L chitosan with a deacetylation degree of 85%, and 0.8 g / L acetic acid; the remaining steps are the same as those in Example 1.

[0072] Example 3:

[0073] The difference from Example 1 is that the treatment liquid in step 2 of this example contains 2.0 g / L hydrogen peroxide, 1.5 g / L chitosan with a deacetylation degree of 85%, and 0.8 g / L acetic acid; the remaining steps are the same as those in Example 1.

[0074] Example 4:

[0075] The difference from Example 1 is that the glue point coverage in step 3 of this embodiment is controlled to be 60%; the remaining steps are the same as Example 1.

[0076] Example 5:

[0077] Different from Example 1, the treatment liquid in step 2 of this embodiment contains 1.5 g / L hydrogen peroxide, 1.5 g / L chitosan with a deacetylation degree of 85%, and 0.8 g / L acetic acid, and the glue point coverage in step 3 is controlled to be 60%; the remaining steps are the same as Example 1.

[0078] Example 6:

[0079] Different from Example 1, the treatment liquid in step 2 of this embodiment contains 2.0 g / L hydrogen peroxide, 1.5 g / L chitosan with a deacetylation degree of 85%, and 0.8 g / L acetic acid, and the glue point coverage in step 3 is controlled to be 60%; the remaining steps are the same as Example 1.

[0080] Example 7:

[0081] Different from Example 1, the glue point coverage in step 3 of this Example 4 is controlled to be 70%; the remaining steps are the same as Example 1.

[0082] Example 8:

[0083] Different from Example 1, the treatment liquid in step 2 of this embodiment contains 1.5 g / L hydrogen peroxide, 1.5 g / L chitosan with a deacetylation degree of 85%, and 0.8 g / L acetic acid, and the glue point coverage in step 3 is controlled to 70%; the remaining steps are the same as Example 1.

[0084] Example 9:

[0085] Different from Example 1, the treatment liquid in step 2 of this embodiment contains 2.0 g / L hydrogen peroxide, 1.5 g / L chitosan with a deacetylation degree of 85%, and 0.8 g / L acetic acid, and the glue point coverage in step 3 is controlled to be 70%; the remaining steps are the same as Example 1.

[0086] Comparative Example 1:

[0087] Different from Example 5, this comparative example omits the pretreatment of the wool blended surface layer in step 2; the remaining steps are the same as those in Example 5.

[0088] Comparative Example 2:

[0089] Different from Example 5, the pretreatment of the wool blended surface layer in step 2 of this comparative example includes immersing the wool blended surface layer in a treatment solution containing 3.0 g / L sodium hypochlorite (pH 4.0), controlling the residual rate to 80%, treating it at 25°C for 20 minutes, and washing it with water until it is neutral; the remaining steps are the same as in Example 5.

[0090] Comparative Example 3:

[0091] Different from Example 5, in step 3 of this comparative example, a hot-melt polyurethane adhesive (coating amount 25 g / m2) was applied to the entire surface of the PU-based composite film with a thickness of 0.025 mm. 2 ); The remaining steps are the same as in Example 5.

[0092] Experimental Example 1:

[0093] The wool blended fabrics prepared in Examples 1-9 and Comparative Examples 1-3 were taken as samples and performance tests were performed according to standard methods:

[0094] 1. Use a fabric friction tester to measure the friction coefficient in the forward and reverse directions of the scales 20 times each under the conditions of a load of 3N, a speed of 1mm / s, a temperature of 40℃±1℃ / RH65%±3%, and calculate the absolute difference Δμ as the directional friction coefficient difference test item;

[0095] 2. Using a 3nm resolution scanning electron microscope, a 500x magnification observation of the gold-sprayed fabric cross-section was performed. 50 glue spots were selected and measured for their penetration depth into the wool blended fabric surface layer as the glue spot penetration depth test item.

[0096] 3. In an environment with a temperature of 38°C ± 0.5°C / RH of 90% ± 2% and a wind speed of 0.5 m / s, measure the water vapor transmission rate of a 20 cm² sample for 24 hours as the moisture permeability test item;

[0097] 4. Use a household washing machine at 40°C ± 2°C on the gentle cycle with 50g of standard detergent to perform 50 wash and dry cycles. Calculate the area change as the washing shrinkage test item.

[0098] 5. Under the conditions of single fiber clamping distance of 20mm and tensile speed of 10mm / min, measure the average breaking strength of 30 fibers and compare the data before and after treatment to calculate the strength loss rate as the fiber strength loss rate test item.

[0099] The results are shown in the following table:

[0100] Table 1 Experimental results comparison table

[0101]

[0102] When the hydrogen peroxide concentration in the pretreatment solution increased from 1.0 g / L to 1.5 g / L, Δμ decreased from 0.105 to 0.062. This is due to the increased selectivity of the oxidation reaction. At a concentration of 1.5 g / L, hydrogen peroxide, driven by steam thermodynamics, penetrates the edges of the wool scales, preferentially breaking disulfide-rich keratin and generating hydrophilic sulfonic acid groups. At the same time, the chitosan cationic film covers the stepped grooves of the scales through electrostatic attraction in the pH range of 5.4-5.6, converting interfiber slippage into low-friction motion within the film layer and reducing the difference in forward and reverse friction between the scales by 43%. However, although increasing the concentration to 2.0 g / L further reduced Δμ to 0.035, the excessive diffusion of the oxidant into the main area of ​​the scales destroyed the highly cross-linked stratum corneum, causing the fiber strength loss rate to rise to 0.041%, increasing the etching depth of the scale surface, and inducing fibrillated microcracks.

[0103] The coverage of glue dots increased from 50% to 60%, and the penetration depth jumped from 50.6% to 65.1%. Through the geometric optimization of the diamond grid array, the spacing between glue dots at 60% coverage formed an optimal anchoring distance of 1.2-1.5 times the fiber diameter. The molten colloid was constrained by the grid node space during capillary climbing, forming a dendritic penetration network along the micro grooves on the surface of the wool fiber. However, at 50% coverage, due to the sparse anchoring points, it was difficult for the colloid to break through the capillary energy barrier between the fiber bundles. When the coverage was increased to 70%, the glue dots were too dense, causing the adjacent units to melt and merge, blocking the prefabricated 50μm through micropores, and reducing the moisture permeability from 3050g / m 2 / 24h drops sharply to 2680g / m 2 / 24h, the reduction in the cross-sectional area of ​​the microporous channel causes the tortuosity of the water vapor diffusion path to increase by 2.3 times.

[0104] It can be seen that 1.5g / L hydrogen peroxide reduces the surface energy of wool fibers to 32mN / m, a 40% decrease compared with untreated ones, and the contact angle hysteresis is reduced, creating a low-energy barrier interface for colloidal wetting; at the same time, the diamond array at 60% coverage makes the external force transmission path 45° dislocated from the warp and weft directions of the fabric, and converts the in-plane shear stress into a composite load of normal compression and tangential tension through vector decomposition, significantly inhibiting the interface slip under water washing stress and reducing the washing shrinkage rate to 0.012%.

[0105] In addition, the fiber strength loss rate of comparative example 2 reached 26.3%, which was due to the fact that sodium hypochlorite produced atomic oxygen in an acidic environment, indiscriminately attacking the peptide bonds of wool, resulting in hydrolysis and breakage of the fiber body; the moisture permeability of comparative example 3 dropped sharply to 1480g / m 2 / 24h, this is because the full coverage coating completely blocks the microporous channels, and water vapor needs to dissolve and diffuse through the polyurethane membrane, and the permeation rate is 5.7 times lower than that of gas phase diffusion.

[0106] In summary, 1.5g / L hydrogen peroxide precisely modifies chemical groups at the edges of the scales, providing a low-energy spreading interface for the diamond-shaped grid with 60% adhesive dot coverage. The latter, through topological constraints, balances mechanical anchoring with microporous moisture permeability. These two synergistically overcome the technical contradiction in traditional processes where high anchoring strength inevitably sacrifices moisture permeability.

[0107] The above description is based on the ideal embodiment of the present invention. Based on the above description, relevant personnel can make various changes and modifications without departing from the technical scope of this invention. The technical scope of this invention is not limited to the content of the specification and must be determined according to the scope of the claims.

Claims

1. A method for preparing a wool blended fabric, characterized in that: The following steps are involved: Step 1: Prepare a functional support base layer; Step 2: preparing a wool blended surface layer and pre-treating it; the pre-treatment comprises immersing the wool blended surface layer in a treatment solution comprising hydrogen peroxide, chitosan, and acetic acid, followed by saturated steam treatment to modify the edges of the wool scales; the treatment solution comprises 1.2-1.8 g / L hydrogen peroxide, 1.3-1.7 g / L chitosan with a deacetylation degree of 85%, and 0.7-0.9 g / L acetic acid; Step 3: preparing a PU-based composite film and performing a glue dot process; the glue dot process includes applying a hot-melt polyurethane glue on the surface of the PU-based composite film to form glue dots arranged in a diamond grid array with a coverage rate of 50-70%, and prefabricating a through micropore at the center of each glue dot; Step 4: stacking the functional support bottom layer, the PU-based composite film after the dispensing treatment, and the pre-treated wool blended surface layer in sequence, and hot pressing and laminating to obtain a composite fabric; Step 5: post-processing the composite fabric.

2. The preparation method according to claim 1, characterized in that The preparation process of the functional support bottom layer includes using a water jet loom to weave 90% to 94% by mass of fine-denier nylon filaments and 6% to 10% by mass of carbon fiber conductive yarns in a plain weave, controlling the warp density to 210-230 strands / inch and the weft density to 170-190 strands / inch, to form a functional support bottom layer with a grammage of 115-125g / m².

3. The preparation method according to claim 1, characterized in that The saturated steam treatment includes controlling the rolling rate to 75%-85% and maintaining the temperature in an environment of 100-104° C. for 2.5-3.5 minutes.

4. The preparation method according to claim 1, characterized in that The preparation process of the wool blended surface layer includes using a rapier loom to weave a blended yarn of fine wool fiber with a mass fraction of 52% to 58%, hollow polyester staple fiber with a mass fraction of 33% to 37%, and elastic filament with a mass fraction of 8% to 12%, in a 2 / 2 twill weave, controlling the warp density to 170-190 strands / inch and the weft density to 150-170 strands / inch, to form a wool blended surface layer with a grammage of 115-125g / m².

5. The preparation method according to claim 1, characterized in that In the dispensing process, a hot melt polyurethane adhesive with a melt index of 115-125 g / 10 min is used; The diameter of the glue dots formed is 0.28-0.32mm; The diameter of the through micropores is 48-52 μm.

6. The preparation method according to claim 1, characterized in that The preparation process of the PU-based composite film includes melt-blending 87.5-88.5% by mass of a polyether polyurethane resin and 11.5-12.5% ​​by mass of thermoplastic polyurethane elastomer particles through a twin-screw extruder, and casting the resulting mixture into a PU-based composite film with a thickness of 0.024-0.026 mm at a melt temperature of 185-190° C. and a screw speed of 120-150 rpm.

7. The preparation method according to claim 1, characterized in that The hot pressing compounding comprises laminating at a temperature of 145-155° C., a pressure of 0.65-0.75 MPa, and a line speed of 2.4-2.6 m / min.

8. The preparation method according to claim 1, characterized in that The post-treatment includes immersing the composite fabric in a C6 fluorine-containing water repellent working solution with a mass concentration of 28-32 g / L, controlling the rolling rate to 70%-75%, and then subjecting the composite fabric to a hot air circulation setting treatment at 168-172° C. for 55-65 seconds.

9. The preparation method according to claim 1, characterized in that The post-treatment includes applying a 4.8-5.2 kV high voltage electric field to the functional support bottom layer and maintaining a directional discharge for 28-32 seconds in a nitrogen protective atmosphere.

10. A wool blended fabric, prepared based on the preparation method according to any one of claims 1 to 9.

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