Knitted fabric with superfine fibers and preparation method thereof

Abstract

The invention discloses a knitted fabric with superfine fibers and a preparation method thereof, the knitted fabric comprises a superfine fiber layer, a substrate layer and a functional coating, the superfine fiber layer is formed by compounding polyester superfine fibers and polyamide superfine fibers with the diameter of 0.1-0.5 micron, and the mass ratio of the polyester superfine fibers to the polyamide superfine fibers is 3: 1-5: 1; the substrate layer is formed by interweaving conventional polyester fibers and elastic fibers in a mass ratio of 8: 2; the functional coating is composed of silane coupling agent modified nano titanium dioxide and an antibacterial silver ion loaded chitosan solution, and the thickness of the coating is 0.5-2 microns. The fabric prepared through the preparation method has a multi-layer composite structure, the fiber diameter is evenly smaller than 0.5 micrometer, the fabric has the silk-like soft hand feeling and the excellent ventilation and perspiration and antibacterial and anti-ultraviolet functions, the preparation process is free of solvent pollution and efficient, large-scale production can be achieved, and the additional value of textiles is remarkably improved.

Description

Technical Field

[0001] This invention belongs to the field of textile technology, specifically a knitted fabric with microfiber and its preparation method. Background Technology

[0002] Knitted fabrics are made by bending yarns into loops and interlocking them using knitting needles. They can be divided into weft knitting and warp knitting based on the weaving method. Weft knitting uses one or more yarns to form loops along the transverse direction of the fabric, resulting in good elasticity and extensibility. Warp knitting uses multiple yarns to form loops simultaneously along the longitudinal direction of the fabric, resulting in a stable structure that is less prone to unraveling. Warp knitting offers good elasticity, a comfortable and form-fitting fit, and ease of wear. The interlocking loops create numerous air pockets, providing excellent warmth. When subjected to wrinkling forces, the loops can shift, and they quickly return to their original state after the wrinkle disappears, exhibiting excellent wrinkle resistance. Knitted fabrics are widely used in clothing, such as underwear, sportswear, sweaters, and dresses, and are also commonly used in home textiles, such as bed sheets and bedspreads. They also have applications in industry, agriculture, and healthcare, such as dust filter cloths and artificial blood vessels.

[0003] Existing traditional knitted fabrics mainly rely on cotton, wool, or conventional synthetic fibers such as polyester and nylon. Their fiber diameters are typically between 10 and 20 micrometers. While this coarse fiber structure provides basic mechanical strength and durability, it also brings many problems. First, the high surface roughness results in a stiff, less silky feel and poor wearing comfort. Second, the small surface area limits the fabric's moisture-wicking properties, making it prone to feeling stuffy in humid environments. Third, the dyeing uniformity is poor, the color change is slow, and it is prone to fading. Finally, in terms of functionality, such as waterproofing, stain resistance, and antibacterial properties, traditional fabrics often require additional chemical treatments, increasing costs and potentially introducing environmental pollution. Summary of the Invention

[0004] The purpose of this section is to outline some aspects of embodiments of the present invention and to briefly describe some preferred embodiments. Simplifications or omissions may be made in this section, as well as in the abstract and title of this application, to avoid obscuring the purpose of these documents; however, such simplifications or omissions should not be construed as limiting the scope of the invention.

[0005] To address the issues raised in the background section regarding the high surface roughness of traditional knitted fabrics, which results in stiffness, lack of silkiness, and poor wearing comfort; the small specific surface area limiting the fabric's moisture absorption and wicking properties, leading to stuffiness in humid environments; poor dyeing uniformity, slow color change, and easy fading; and finally, the fact that traditional fabrics often require additional chemical treatments for functional properties such as waterproofing, stain resistance, and antibacterial properties, increasing costs and potentially causing environmental pollution, this invention adopts the following technical solution.

[0006] A knitted fabric with microfibers includes a microfiber layer, a base layer, and a functional coating. The microfiber layer is composed of polyester microfibers and polyamide microfibers with a diameter of 0.1-0.5 micrometers, and the mass ratio of the polyester microfibers to the polyamide microfibers is 3:1-5:1. The base layer is composed of conventional polyester fibers and elastic fibers interwoven in a mass ratio of 8:2. The functional coating is composed of silane coupling agent modified nano-titanium dioxide and chitosan solution loaded with antibacterial silver ions, and the coating thickness is 0.5-2 micrometers.

[0007] Preferably, the molecular weight of the polyester microfiber is 20,000-30,000 g / mol, and the amino end group content of the polyamide microfiber is 50-70 μeq / g.

[0008] Preferably, the conventional polyester fiber has a diameter of 5-10 micrometers, the elastic fiber is spandex, and the base layer has a basis weight of 150-200 g / m².

[0009] Preferably, the microfiber layer is composited onto the base layer by electrospinning and knitting processes, and the thickness of the microfiber layer is 20-60 micrometers.

[0010] Preferably, the functional coating is uniformly sprayed onto the surface of the ultrafine fiber layer, and the nano-titanium dioxide has a particle size of 10-30 nm and a silver ion loading of 0.1-0.5 wt%.

[0011] A method for preparing a knitted fabric with microfibers includes the following steps: Step 1: Preparation of microfiber solution: Dissolve polyester resin and polyamide resin separately in dimethylformamide / tetrahydrofuran mixed solvent with a mass concentration of 15-20%, then mix them at a mass ratio of 3:1-5:1, add 0.5-1% surfactant, and stir until homogeneous. Step 2, electrospinning: The solution obtained in Step 1 is spun through an electrospinning device. The spinning voltage is 15-25kV, the receiving distance is 10-15 cm, the ambient temperature is 20-30℃, and the humidity is 40-60%, to obtain an ultrafine fiber membrane with a diameter of 0.1-0.5 micrometers. Step 3, Base Knitting: Using a 28-32 needle single-sided weft knitting machine, feed regular polyester yarn and spandex yarn in an 8:2 ratio to knit a base layer with a weight of 150-200 g / m². Step 4, Composite Integration: The ultrafine fiber membrane obtained in Step 2 is composited onto the substrate layer obtained in Step 3 using a hot press roller. The hot pressing temperature is 80-100℃, the pressure is 0.5-1 MPa, and the time is 30-60 s. Step 5: Application of functional coating: Disperse nano-titanium dioxide in chitosan solution, add silane coupling agent, spray onto the surface of composite fabric, and dry at 60-80℃. Step 6, Post-processing: Washing and setting to obtain the knitted fabric with microfiber.

[0012] Preferably, in step one, the stirring speed is 500-800 rpm, the time is 2-4 h, and the solvent volume ratio is 1:1-2:1.

[0013] Preferably, in step two, the spinning speed is 0.5-1 mL / h and the collecting roller speed is 100-300 rpm.

[0014] Preferably, the roller speed of the hot press roller in step four is 0.3-0.7 m / min, and the peel strength after lamination is greater than 3 N / cm.

[0015] Preferably, in step five, the spraying pressure is 0.1-0.3 MPa, the coating amount is 1-2 g / m², and the amount of silane coupling agent added is 1-2% of the mass of nano-titanium dioxide.

[0016] Compared with the prior art, the beneficial effects of the present invention are as follows: This invention precisely controls the diameter of ultrafine fibers to 0.1-0.5 micrometers using the aforementioned preparation method, significantly increasing the specific surface area and resulting in a silk-like smoothness, thus greatly improving wearing comfort. Compared to traditional melt spinning, it improves diameter uniformity and reduces breakage rate; moreover, electrospinning avoids high-temperature melting, saving energy consumption and reducing production costs due to the easy recycling of solvents used; furthermore, this fabric achieves uniform fiber diameter of less than 0.5 micrometers through a multi-layer composite structure, possessing a silk-like softness, excellent breathability and sweat-wicking properties, and antibacterial and UV protection functions. The preparation process is solvent-free, highly efficient, and scalable, significantly increasing the added value of textiles. Detailed Implementation

[0017] Many specific details are set forth in the following description in order to provide a full understanding of the invention. However, the invention may also be practiced in other ways different from those described herein, and those skilled in the art can make similar extensions without departing from the spirit of the invention. Therefore, the invention is not limited to the specific embodiments disclosed below.

[0018] Secondly, the term "one embodiment" or "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The phrase "in one embodiment" appearing in different places throughout this specification does not necessarily refer to the same embodiment, nor is it a single or selective embodiment that mutually excludes other embodiments. The present invention provides the following embodiments.

[0019] Example 1: A knitted fabric with microfibers, characterized in that it comprises the following components: (1) Microfiber layer: composed of polyester microfiber and polyamide microfiber with a diameter of 0.1-0.5 micrometers, wherein the mass ratio of polyester microfiber to polyamide microfiber is 3:1 to 5:1; the thickness of this layer is 20-60 micrometers, providing the main softness and functional interface of the fabric; (2) Base layer: It is made of conventional polyester fiber and elastic fiber interwoven together. The conventional polyester fiber has a diameter of 5-10 micrometers and the elastic fiber is spandex, with a mass ratio of 8:2. The weight of this layer is 150-200 g / m², which ensures the mechanical strength and elastic recovery of the fabric. (3) Functional coating: composed of nano-titanium dioxide modified by silane coupling agent and chitosan solution loaded with antibacterial silver ions, with a coating thickness of 0.5-2 micrometers; nano-titanium dioxide particle size of 10-30 nm, and silver ion loading of 0.1-0.5 wt%.

[0020] The microfiber layer is formed in situ on the knitted base layer directly by electrospinning technology and fixed by hot pressing; the functional coating is uniformly attached to the surface of the microfiber layer by high-pressure spraying to form a dense network structure, which improves adhesion and durability.

[0021] In this embodiment, the polyester microfiber has a molecular weight of 20,000-30,000 g / mol and an intrinsic viscosity of 0.6-0.8 dL / g to ensure the rheological properties of the spinning solution; the polyamide microfiber has an amino end group content of 50-70 μeq / g and a carboxyl end group content of <20 μeq / g to promote inter-fiber hydrogen bond crosslinking and enhance interlayer bonding.

[0022] In this embodiment, the crystallinity of the conventional polyester fiber is 40-50%, and the breaking strength is >4 cN / dtex; the elongation of the spandex fiber is >400%, and the resilience is >95%, so as to achieve the dynamic adaptability of the fabric.

[0023] In this embodiment, the silane coupling agent is selected from KH-550 or KH-570, and the amount added is 1-2% of the mass of nano-titanium dioxide; the chitosan has a molecular weight of 50-100kDa and a degree of deacetylation >85%, providing biocompatibility and antibacterial matrix.

[0024] A method for preparing a knitted fabric with microfibers includes the following steps: Step 1: Preparation of microfiber solution: Polyester resin and polyamide resin are dissolved separately in dimethylformamide / tetrahydrofuran mixed solvent with a mass concentration of 15%, and then mixed at a mass ratio of 3:1. 0.5% surfactant is added and stirred evenly. The stirring speed is 500 rpm and the time is 2 h. The volume ratio of the solvent is 1:1.

[0025] Step 2, electrospinning: The solution obtained in Step 1 is spun through an electrospinning device with a spinning voltage of 15 kV, a receiving distance of 10 cm, an ambient temperature of 20℃, and a humidity of 40%, to obtain an ultrafine fiber membrane with a diameter of 0.1 micrometers; the spinning speed is 0.5 mL / h, and the collecting roller speed is 100 rpm.

[0026] Step 3, Base Knitting: Using a 28-gauge single-sided weft knitting machine, feed regular polyester yarn and spandex yarn in an 8:2 ratio to knit a base layer with a weight of 150 g / m². Step 4, Composite Integration: The ultrafine fiber membrane obtained in Step 2 is composited onto the substrate layer obtained in Step 3 using a hot press roller. The hot pressing temperature is 80℃, the pressure is 0.5 MPa, and the time is 30 s. The roller speed of the hot press roller is 0.3 m / min. The peel strength after composite is greater than 3 N / cm.

[0027] Step 5: Application of functional coating: Disperse nano-titanium dioxide in chitosan solution, add silane coupling agent, spray onto the surface of composite fabric, and dry at 60°C; spray pressure is 0.1 MPa, coating amount is 1 g / m², and the amount of silane coupling agent added is 1% of the mass of nano-titanium dioxide.

[0028] Step 6, Post-processing: Washing and setting to obtain the knitted fabric with microfiber.

[0029] Example 2: A method for preparing a knitted fabric with microfibers includes the following steps: Step 1: Preparation of the microfiber solution: Polyester resin and polyamide resin are dissolved separately in a dimethylformamide / tetrahydrofuran mixed solvent with a mass concentration of 20%, and then mixed at a mass ratio of 5:1. 1% surfactant is added and stirred until homogeneous. The stirring speed is 800 rpm and the time is 4 h. The volume ratio of the solvent is 2:1.

[0030] Step 2, electrospinning: The solution obtained in Step 1 is spun through an electrospinning device with a spinning voltage of 25 kV, a receiving distance of 15 cm, an ambient temperature of 30℃, and a humidity of 60%, to obtain an ultrafine fiber membrane with a diameter of 0.5 micrometers; the spinning speed is 1 mL / h, and the collecting roller speed is 300 rpm.

[0031] Step 3, Base Knitting: Using a 32-gauge single-sided weft knitting machine, feed regular polyester yarn and spandex yarn in an 8:2 ratio to knit a base layer with a weight of 200 g / m². Step 4, Composite Integration: The ultrafine fiber membrane obtained in Step 2 is composited onto the substrate layer obtained in Step 3 using a hot press roller. The hot press temperature is 100℃, the pressure is 1 MPa, and the time is 60 s. The roller speed of the hot press roller is 0.7 m / min. The peel strength after composite is greater than 3 N / cm.

[0032] Step 5: Application of functional coating: Disperse nano-titanium dioxide in chitosan solution, add silane coupling agent, spray onto the surface of composite fabric, and dry at 80°C; spray pressure is 0.3 MPa, coating amount is 2 g / m², and the amount of silane coupling agent added is 2% of the mass of nano-titanium dioxide.

[0033] Step 6, Post-processing: Washing and setting to obtain the knitted fabric with microfiber.

[0034] Example 3: A method for preparing a knitted fabric with microfibers includes the following steps: Step 1: Preparation of microfiber solution: Polyester resin and polyamide resin are dissolved separately in dimethylformamide / tetrahydrofuran mixed solvent with a mass concentration of 18%, and then mixed at a mass ratio of 4:1. 0.7% surfactant is added and stirred evenly. The stirring speed is 650 rpm and the time is 3 h. The volume ratio of the solvent is 1:1.

[0035] Step 2, electrospinning: The solution obtained in step (1) is spun through an electrospinning device with a spinning voltage of 20kV, a receiving distance of 18 cm, an ambient temperature of 25℃, and a humidity of 50%, to obtain an ultrafine fiber membrane with a diameter of 0.3 micrometers; the spinning speed is 0.8 mL / h, and the collecting roller speed is 200 rpm.

[0036] Step 3, Base Knitting: Using a 30-gauge single-sided weft knitting machine, feed regular polyester yarn and spandex yarn in an 8:2 ratio to knit a base layer with a weight of 175g / m². Step 4, Composite Integration: The ultrafine fiber membrane obtained in step (2) is composited onto the substrate layer obtained in step (3) using a hot press roller. The hot press temperature is 90℃, the pressure is 0.8 MPa, and the time is 45 s. The roller speed of the hot press roller is 0.5 m / min. The peel strength after composite is greater than 3 N / cm.

[0037] Step 5: Application of functional coating: Disperse nano-titanium dioxide in chitosan solution, add silane coupling agent, spray onto the surface of composite fabric, and dry at 75°C; spray pressure is 0.2 MPa, coating amount is 1.5 g / m², and the amount of silane coupling agent added is 1.5% of the mass of nano-titanium dioxide.

[0038] Step 6, Post-processing: Washing and setting to obtain the knitted fabric with microfiber.

[0039] Based on the fabric data obtained from the above experiments, Example 3 is the optimal solution for this technical solution. This technical solution precisely controls the diameter of ultrafine fibers to 0.1-0.5 micrometers using the aforementioned preparation method, significantly increasing the specific surface area and resulting in a silk-like smoothness, thus significantly improving wearing comfort. Compared to traditional melt spinning, it improves diameter uniformity and reduces breakage rate; moreover, electrospinning avoids high-temperature melting, saving energy consumption and electricity, and the solvents used are easily recyclable, reducing production costs; furthermore, this fabric achieves uniform fiber diameter of less than 0.5 micrometers through a multi-layer composite structure, possessing a silk-like softness, excellent breathability and sweat-wicking, antibacterial and UV protection functions, and the preparation process is solvent-free, highly efficient, and scalable, significantly increasing the added value of textiles.

[0040] The above description, in conjunction with specific embodiments, provides a further detailed explanation of the present invention. It should not be construed that the specific implementation of the present invention is limited to these descriptions. For those skilled in the art, several simple deductions or substitutions can be made without departing from the concept of the present invention, and all such deductions or substitutions should be considered to fall within the scope of protection defined by the claims submitted herein.

Claims

1. A knitted fabric having ultra-fine fibers, characterized by, The application relates to a knitted fabric with superfine fibers, which comprises a superfine fiber layer, a base layer and a functional coating layer, wherein the superfine fiber layer is composed of polyester superfine fibers and polyamide superfine fibers with a diameter of 0.1-0.5 microns, the mass ratio of the polyester superfine fibers to the polyamide superfine fibers is 3:1-5:1; the base layer is composed of conventional polyester fibers and elastic fibers with a mass ratio of 8:2; and the functional coating layer is composed of nano-titanium dioxide modified by a silane coupling agent and an antibacterial silver ion loaded chitosan solution, and the coating layer has a thickness of 0.5-2 microns.

2. The knit fabric with microfibers according to claim 1, wherein, The polyester superfine fibers have a molecular weight of 20,000-30,000 g / mol, and the polyamide superfine fibers have an amino end group content of 50-70 mu eq / g.

3. The knit fabric having microfibers according to claim 1, wherein, The conventional polyester fibers have a diameter of 5-10 microns, the elastic fibers are spandex, and the base layer has a grammage of 150-200 g / m2.

4. The knit fabric having microfibers according to claim 1, wherein, The superfine fiber layer is combined with the base layer through electrospinning and a knitting process, and the thickness of the superfine fiber layer is 20-60 microns.

5. The knit fabric having microfibers according to claim 1, wherein, The functional coating layer is uniformly sprayed on the superfine fiber layer, the nano-titanium dioxide has a particle size of 10-30 nm, and the silver ion loading amount is 0.1-0.5 wt%.

6. A method for manufacturing a knitted fabric having microfibers, applied to the knitted fabric having microfibers according to any one of claims 1 to 5, characterized by, The application further relates to a preparation method of the knitted fabric with superfine fibers, which comprises the following steps: Step one: superfine fiber solution preparation: polyester resin and polyamide resin are respectively dissolved in a dimethylformamide / tetrahydrofuran mixed solvent with a mass concentration of 15-20%, then mixed according to a mass ratio of 3:1-5:1, and 0.5-1% of a surfactant is added and uniformly stirred; Step two: electrospinning: the solution obtained in step one is spun through an electrospinning device, the spinning voltage is 15-25 kV, the receiving distance is 10-15 cm, the environmental temperature is 20-30 DEG C, and the humidity is 40-60%, so as to obtain superfine fiber membranes with a diameter of 0.1-0.5 microns; Step three: base knitting: a single-jersey weft knitting machine with 28-32 needles is adopted, conventional polyester yarn and spandex yarn are fed according to a ratio of 8:2, and a base layer with a grammage of 150-200 g / m2 is knitted; Step four: composite integration: the superfine fiber membranes obtained in step two are combined with the base layer obtained in step three through a hot-pressing roller, the hot-pressing temperature is 80-100 DEG C, the pressure is 0.5-1 MPa, and the time is 30-60 s; Step five: functional coating application: nano-titanium dioxide is dispersed in a chitosan solution, a silane coupling agent is added, and the mixture is sprayed on the surface of the composite fabric, and the drying temperature is 60-80 DEG C; Step six: post-treatment: washing and setting, so as to obtain the knitted fabric with superfine fibers.

7. The method of claim 6, wherein the step of knitting the fabric is performed by using a knitting machine. In step one, the stirring speed is 500-800 rpm, and the stirring time is 2-4 h; and the volume ratio of the solvents is 1:1-2:

1.

8. The method of claim 6, wherein the step of knitting the fabric is performed by using a knitting machine. In step two, the spinning speed is 0.5-1 mL / h, and the rotating speed of the collection roller is 100-300 rpm.

9. The method of claim 6, wherein the step of knitting the fabric is performed by using a knitting machine. In step four, the roller speed of the hot-pressing roller is 0.3-0.7 m / min, and the peeling strength after the combination is greater than 3 N / cm.

10. The method of claim 6, wherein the knit fabric is prepared by using a needle with a diameter of 0.2 mm or less. In step five, the spraying pressure is 0.1-0.3 MPa, the coating amount is 1-2 g / m2, and the addition amount of the silane coupling agent is 1-2% of the mass of the nano-titanium dioxide.