Processing method of knitted fabric with high solarization durability and anti-ultraviolet function

Abstract

The invention discloses a processing method of high-solarization durable anti-ultraviolet functional knitted fabric, which comprises the following steps: preparing chinlon yarn with a core-sheath structure, a core layer of the chinlon yarn is full-dull chinlon in which nano titanium dioxide particles are uniformly dispersed, and a sheath layer comprises the following components in percentage by mass: 75-87% of chinlon fiber, 10-20% of rare earth oxide and 3-5% of coating agent, the mass ratio of the sheath layer in the chinlon yarn is 20-30%; performing ultrahigh stitch length weaving; and dyeing treatment. The knitted fabric woven by the method is compact in structure, good in uniformity and low in porosity, has excellent anti-ultraviolet performance, high light fastness and durability, can realize UPF100 < + >, high light fastness greater than or equal to 4-5 levels, T (UVA) AV < 4%, still keeps excellent anti-ultraviolet performance, color fastness and mechanical properties after long-term solarization and multiple washing, and has a wide application prospect. Unification of anti-ultraviolet functionality and durability is achieved, the service life of the fabric is long, and permanent and efficient sun protection can be provided for the human body.

Description

Technical Field

[0001] This invention belongs to the field of knitted fabric processing technology in textiles and apparel, and specifically relates to a processing method for a high-sunlight-resistant, durable, and UV-resistant knitted fabric. Background Technology

[0002] In summer, the sun's radiation is strong, and people are easily exposed to excessive ultraviolet rays when they are outdoors. This can not only cause textiles to fade and become brittle, but also cause sunburn and aging of human skin, producing melanin and age spots. In severe cases, it may even induce skin cancer.

[0003] Currently, there are two main methods for preparing UV-resistant fabrics on the market: one is to add inorganic nano-UV shielding agents or graphene to chemical fibers, and the other is to add UV-resistant agents during fabric dyeing or finishing. However, these traditional methods have many shortcomings: adding inorganic nano-UV shielding agents (such as nano-titanium dioxide and zinc dioxide) to chemical fibers only provides UV protection against certain wavelengths (such as UVB). After prolonged shielding, the UV protection function weakens, and the fibers age and fade. Graphene fibers themselves are dark brown, which cannot meet the requirements of white and light-colored clothing fabrics. Fabrics with UV-resistant agents added through finishing processes such as setting or coating, or through dyeing, do not have a strong bond between the UV-resistant agent and the fabric, which not only affects the fabric's feel and color appearance, but also makes it difficult to maintain the UV protection effect.

[0004] Chinese patent CN117144501A discloses an antibacterial and UV-resistant fiber material and its preparation method. This material uses a core-sheath structure, where the sheath covers the core, achieving antibacterial properties in the sheath and UV resistance in the core. However, it fails to provide full-spectrum UV protection, and the fabric is prone to aging and fading. Chinese patent CN107119372A discloses a high-efficiency, long-lasting graphene UV-resistant fabric and its preparation method. This uses a novel graphene fiber material, allowing the fabric to achieve permanent UV resistance without the use of UV-blocking agents or coatings during dyeing and finishing. However, the fiber is extremely expensive, the yarn has a dark brown hue (as the pigment itself strongly absorbs UV light), and it cannot be used to produce a light-colored fabric through subsequent dyeing and finishing processes, significantly limiting its practical application. Other Chinese patents, such as the production process of white nylon UV-resistant fabric disclosed in CN109537132A, the manufacturing method of a lightweight nylon UV-resistant fabric disclosed in CN115538159A, and the high-fastness UV-resistant fabric and its preparation method and application disclosed in CN118814497A, all use one or more steps of setting, coating, and dyeing to add different UV-resistant agents to achieve the UV-resistant effect. However, the UV-resistant effect is difficult to maintain, and adding UV-resistant agents through setting and coating seriously affects the fabric's feel and color appearance.

[0005] It is evident that existing technologies generally suffer from poor synergistic effects of multiple UV-resistant agents, inadequate fabric dyeing performance, and insufficient durability of UV resistance. Therefore, the market currently lacks a UV-resistant fabric that can provide UV protection across the entire wavelength range (200nm–400nm), is permanently washable, does not affect the fabric's feel or appearance, and possesses high lightfastness and aging resistance. Summary of the Invention

[0006] The technical problem this invention aims to solve is to provide a processing method for a high-sunlight-resistant, durable, and UV-resistant functional knitted fabric, addressing the shortcomings of existing technologies. This method utilizes the complementary properties of nylon yarns with core-sheath structures and spandex yarns, combined with ultra-high gauge weaving technology and specific dyeing processes, to weave a tightly woven, uniform, and low-porosity knitted fabric. This fabric exhibits excellent UV resistance, high sunlight fastness, and durability, achieving a UPF of 100+ and a sunlight fastness rating of ≥4-5. Its long-wave ultraviolet transmittance (T(UVA)) is also high. AV With a UV index of less than 4%, it maintains excellent UV resistance, colorfastness, and mechanical properties even after prolonged sun exposure and multiple washes, achieving a balance between UV protection functionality and durability, extending the fabric's lifespan, and providing permanent and highly effective sun protection for the human body.

[0007] The technical solution adopted by this invention to solve the above-mentioned technical problems is as follows: a processing method for a high-sunlight-resistant, durable, and UV-resistant knitted fabric, comprising the following steps:

[0008] S1. Prepare a nylon yarn with a core-sheath structure. The nylon yarn includes a sheath layer and a core layer. The sheath layer covers the periphery of the core layer. The core layer is a fully dull nylon with uniformly dispersed nano-titanium dioxide particles. The mass percentage composition of the sheath layer includes: 75-87% nylon fiber, 10-20% rare earth oxides, and 3-5% coating agent. The mass percentage of the sheath layer in the nylon yarn is 20-30%.

[0009] S2. Ultra-high gauge knitting: The nylon yarn and spandex yarn are knitted with an ultra-high gauge circular knitting machine, and combined with a shrinkage process, the spandex yarn is pre-shrinked during the knitting process to obtain the fabric.

[0010] S3. Dyeing treatment: Dye the fabric. During dyeing, control the pH of the working solution to 4.5-5, the dyeing temperature to 98-100℃, and the dyeing time to 40-50 minutes. After dyeing, set and dry the fabric to obtain a high-sunlight-resistant, durable, UV-resistant knitted fabric.

[0011] This invention utilizes core-sheath structured nylon yarn as raw material to process high-sunlight-resistant, durable, and UV-resistant functional knitted fabrics. The sheath layer of this nylon yarn possesses unique optical properties due to the presence of rare earth oxides. The rare earth elements in these oxides have a special 4f valence electron layer structure and abundant electron transition energy levels, resulting in excellent light conversion characteristics in the ultraviolet-visible light region. When sunlight shines on the fabric, the sheath layer can efficiently absorb ultraviolet light across the entire 200–400 nm wavelength band and convert it into low-energy, harmless visible light through electron energy level transitions. Furthermore, during this conversion, the sheath layer absorbs almost no visible light, thus ensuring that the original color, appearance, and feel of the fabric remain unaffected. In addition, the core layer of this nylon yarn is a fully matte nylon with uniformly dispersed nano-titanium dioxide particles. The particle size of the nano-titanium dioxide particles is similar to the wavelength of ultraviolet light, and their uniform dispersion within the nylon allows for the scattering of ultraviolet light, altering its propagation direction and further enhancing the UV resistance of the nylon yarn. Therefore, the nylon yarn with a core-sheath structure used in this invention not only achieves durable and stable UV protection performance of the fabric, but also avoids the fabric aging problems that may be caused by traditional UV absorbers, making the fabric's UV protection factor (UPF) exceed 100, achieving a high sun fastness of UPF100+ and ≥4-5, and its long-wave ultraviolet transmittance T(UVA) is also high. AV <4%, it still maintains excellent UV resistance, color fastness and mechanical properties after long-term sun exposure and multiple washings, achieving a balance between UV resistance functionality and durability.

[0012] This invention utilizes an ultra-high gauge circular knitting machine to weave nylon and spandex yarns at ultra-high gauge. This machine can produce knitted fabrics with a tight structure and good uniformity. By combining a shrinkage process and precisely controlling the draft tension and yarn feed speed of the ultra-high gauge circular knitting machine, the spandex yarn undergoes pre-shrinkage during weaving, significantly improving the fabric's density and effectively reducing its porosity. This prevents ultraviolet rays from penetrating the fabric pores, enhancing its physical blocking effect and further strengthening its UV-blocking ability.

[0013] Preferably, the rare earth oxide is one or more of nano-cerium oxide, nano-lanthanum oxide, and nano-samarium oxide, and the particle size D of the rare earth oxide is... 90 It is 600-700nm.

[0014] Preferably, in step S1, the nylon yarn is prepared using a core-sheath spinning process.

[0015] Preferably, in step S1, the coating agent is a mixture of polyethylene wax and polyamide wax, wherein the mass ratio of polyethylene wax to polyamide wax in the mixture is 1:1.

[0016] Preferably, in step S2, an E44-E50 ultra-high gauge circular knitting machine is used to weave the nylon yarn and spandex yarn. During weaving, the yarn tension of the nylon yarn is controlled to be 3.5-5.0 cN and the yarn feeding speed is controlled to be 12-18 m / min, while the draft ratio of the spandex yarn is controlled to be 2.5-3.5 times and the yarn feeding speed is controlled to be 3.5-7.2 m / min.

[0017] Preferably, for non-white knitted fabrics, in step S3, acidic dyes are used to dye the fabric, and lanthanum chloride is added to the working solution as a dyeing accelerator during dyeing. When the above dyeing treatment is applied to non-white fabrics, the lanthanum ions in lanthanum chloride can synergistically complex with the amino groups of nylon fibers and acidic dye molecules to form a more stable ternary coordination structure. This structure can enhance the binding force between the dye and the fiber, making the dye firmly anchored on the fiber surface and forming a new UV-resistant interface layer. This effectively inhibits the desorption and photochemical degradation of dye molecules under light conditions, thereby improving the lightfastness of the fabric. At the same time, lanthanum ions and their compounds have excellent light-shielding properties, selectively absorbing UV light that can damage dyes, capturing free radicals generated by UV excitation, and blocking the photodegradation path of dye molecules, thereby further improving the UV resistance and lightfastness of the fabric.

[0018] In a preferred embodiment, the acid dye is of model number provided by Huntsman Corporation. Products.

[0019] As a further preferred option, for non-white knitted fabrics, the amount of lanthanum chloride added to the working solution is 0.5 to 1% of the fabric mass.

[0020] Preferably, for white knitted fabrics, in step S3, the fabric is dyed using a nylon brightener, wherein the nylon brightener is a stilbene derivative.

[0021] Preferably, in step S3, the setting and drying process involves heat setting at an overfeed rate of 3-10%, a machine speed of 18-25 m / min, and a temperature of 130-150°C to obtain a high-sunlight-resistant, durable, UV-resistant knitted fabric.

[0022] Compared with the prior art, the present invention has the following advantages:

[0023] 1) The processing method of this invention utilizes the complementary characteristics of nylon yarn and spandex yarn with core-sheath structure, combined with ultra-high gauge weaving technology, to weave a knitted fabric with a tight structure, good uniformity and low porosity. While ensuring the breathability of the fabric, it reduces the fabric pores, making it virtually impossible for ultraviolet rays to penetrate the fabric pores, thereby improving the physical blocking effect of the fabric and enhancing the fabric's ability to block ultraviolet rays.

[0024] 2) The knitted fabrics processed by the method of this invention have excellent UV resistance, high light fastness and durability, and can achieve a high light fastness of UPF100+ and ≥4 to 5 levels, with T(UVA) AV With a UV index of less than 4%, it maintains excellent UV resistance, colorfastness, and mechanical properties even after prolonged sun exposure and multiple washes, achieving a balance between UV protection functionality and durability, extending the fabric's lifespan, and providing permanent and highly effective sun protection for the human body.

[0025] 3) For non-white knitted fabrics, the processing method of the present invention adds lanthanum chloride as a dyeing accelerator to the dyeing working solution, so that the dye is firmly anchored on the fiber surface, forming a new anti-ultraviolet interface layer, improving the light fastness of the fabric. At the same time, lanthanum ions and their compounds can capture free radicals generated by ultraviolet excitation and block the photodegradation path of dye molecules, thereby further improving the anti-ultraviolet performance and light fastness of non-white knitted fabrics. For white knitted fabrics, the processing method of the present invention uses stilbene derivatives as nylon whitening agents to dye the fabric, ensuring the whiteness of the fabric while guaranteeing the anti-ultraviolet performance and light fastness. Detailed Implementation

[0026] The present invention will be further described in detail below with reference to embodiments. Raw materials, auxiliaries, processes, equipment, etc., not limited in this invention, all employ conventional techniques in the art. The yarn raw materials and auxiliaries used in the following embodiments are commercially available products.

[0027] Example 1: A processing method for a black knitted fabric with high sun resistance, durability, and UV protection, comprising the following steps:

[0028] S1. A nylon yarn with a core-sheath structure of 40D / 24F is prepared using the existing core-sheath spinning process. The nylon yarn includes a sheath layer and a core layer. The sheath layer covers the periphery of the core layer. The core layer is a commercially available fully dull nylon with uniformly dispersed nano-titanium dioxide particles (content 1.5wt%). The mass percentage composition of the sheath layer includes: 87% nylon fiber, 10% rare earth oxides, and 3% coating agent. The mass percentage of the sheath layer in the nylon yarn is 20%.

[0029] S2. Ultra-high gauge knitting: Using an E44 ultra-high gauge circular knitting machine, 40D / 24F nylon yarn and 20D Lycra spandex yarn are knitted with an ultra-high gauge. During knitting, the yarn tension of the nylon yarn is controlled at 4.8cN and the yarn feed speed is 15m / min. At the same time, the draft ratio of the spandex yarn is controlled at 2.5 times and the yarn feed speed is 6m / min. Combined with shrinkage processing, the spandex yarn is pre-shrinked during the knitting process, and interwoven into an elastic double-sided knitted fabric.

[0030] S3. Dyeing treatment: Acid dyes are used (specifically, the type provided by Huntsman). The product) is dyed on elastic double-sided knitted fabric. The pH value of the working solution is controlled at 4.5 during dyeing. 0.5% owf lanthanum chloride is added to the working solution as a dyeing accelerator. The dyeing temperature is 98℃ and the dyeing time is 50min. The dyed fabric is then set and dried, and heat-set at 150℃ with an overfeed rate of 5% and a machine speed of 20m / min to obtain a black knitted fabric with high sun exposure durability and anti-ultraviolet function.

[0031] The color fastness and UV resistance of the black knitted fabric processed in Example 1 were tested using the methods specified in GB / T 8427-2019 "Textiles - Tests for Color Fastness to Artificial Light: Xenon Arc" and GB / T 18830-2009 "Evaluation of Ultraviolet Protection Performance of Textiles". The test results showed that the black knitted fabric processed in Example 1 had a UV Protection Factor (UPF) exceeding 100, achieving a high light fastness of UPF 100+ and ≥4-5 levels. Its long-wave ultraviolet transmittance (T(UVA)) was also satisfactory. AV <4%, it still maintains excellent UV resistance, color fastness and mechanical properties after long-term sun exposure and multiple washings, achieving a balance between UV resistance functionality and durability.

[0032] Example 2: A processing method for a white knitted fabric with high sun resistance, durability, and UV protection, comprising the following steps:

[0033] S1. A nylon yarn with a core-sheath structure of 30D / 24F is prepared using the existing core-sheath spinning process. The nylon yarn includes a sheath layer and a core layer. The sheath layer covers the periphery of the core layer. The core layer is a commercially available fully dull nylon with uniformly dispersed nano-titanium dioxide particles (content 1.5wt%). The mass percentage composition of the sheath layer includes: 75% nylon fiber, 20% rare earth oxides, and 5% coating agent. The mass percentage of the sheath layer in the nylon yarn is 30%.

[0034] S2. High gauge knitting: Using an E44 high gauge circular knitting machine, 30D / 24F nylon yarn and 20D Lycra spandex yarn are knitted with a high gauge. During knitting, the yarn tension of the nylon yarn is controlled at 4.0cN and the yarn feed speed is 14m / min. At the same time, the draft ratio of the spandex yarn is controlled at 3.5 times and the yarn feed speed is 4m / min. Combined with shrinkage processing, the spandex yarn is pre-shrinked during the knitting process, and interwoven into an elastic double-sided knitted fabric.

[0035] S3. Dyeing treatment: Stilbene derivatives are selected as nylon whitening agents to dye the fabric. During dyeing, the pH value of the working solution is controlled at 5, the dyeing temperature is 98℃, and the dyeing time is 40min. After dyeing, the fabric is set and dried, and then heat set at 130℃ with an overfeed rate of 5% and a machine speed of 18m / min to obtain a white knitted fabric with high sun exposure durability and anti-ultraviolet function.

[0036] The color fastness and UV resistance of the white knitted fabric processed in Example 2 were tested using the methods specified in GB / T 8427-2019 "Textiles - Tests for Color Fastness to Artificial Light: Xenon Arc" and GB / T 18830-2009 "Evaluation of Ultraviolet Protection Performance of Textiles". The test results showed that the white knitted fabric processed in Example 2 had a UV Protection Factor (UPF) exceeding 100, achieving a high light fastness of UPF 100+ and ≥4-5 levels. Its long-wave ultraviolet transmittance (T(UVA)) was also satisfactory. AV <4%, it still maintains excellent UV resistance, color fastness and mechanical properties after long-term sun exposure and multiple washings, achieving a balance between UV resistance functionality and durability.

Claims

1. A processing method for a high-sunlight-resistant, durable, UV-resistant knitted fabric, characterized in that, Includes the following steps: S1. Prepare a nylon yarn with a core-sheath structure. The nylon yarn includes a sheath layer and a core layer. The sheath layer covers the periphery of the core layer. The core layer is a fully dull nylon with uniformly dispersed nano-titanium dioxide particles. The mass percentage composition of the sheath layer includes: 75-87% nylon fiber, 10-20% rare earth oxides, and 3-5% coating agent. The mass percentage of the sheath layer in the nylon yarn is 20-30%. S2. Ultra-high gauge knitting: The nylon yarn and spandex yarn are knitted with an ultra-high gauge circular knitting machine, and combined with a shrinkage process, the spandex yarn is pre-shrinked during the knitting process to obtain the fabric. S3. Dyeing treatment: Dye the fabric. During dyeing, control the pH of the working solution to 4.5-5, the dyeing temperature to 98-100℃, and the dyeing time to 40-50 minutes. After dyeing, set and dry the fabric to obtain a high-sunlight-resistant, durable, UV-resistant knitted fabric.

2. The processing method of the high sun-durability and UV-resistant functional knitted fabric according to claim 1, characterized in that, The rare earth oxide is one or more of nano-cerium oxide, nano-lanthanum oxide, and nano-samarium oxide, and the particle size D of the rare earth oxide is... 90 It is 600-700nm.

3. The processing method of the high sun-durability and UV-resistant functional knitted fabric according to claim 1, characterized in that, In step S1, the nylon yarn is prepared using a core-sheath spinning process.

4. The processing method of a high-sunlight-resistant, durable, UV-resistant knitted fabric according to claim 1, characterized in that, In step S1, the coating agent is a mixture of polyethylene wax and polyamide wax, wherein the mass ratio of polyethylene wax to polyamide wax in the mixture is 1:

1.

5. The processing method of a high-sunlight-resistant, durable, UV-resistant knitted fabric according to claim 1, characterized in that, In step S2, an E44-E50 ultra-high gauge circular knitting machine is used to weave the nylon yarn and spandex yarn. During weaving, the yarn tension of the nylon yarn is controlled at 3.5-5.0 cN and the yarn feed speed is controlled at 12-18 m / min. At the same time, the draft ratio of the spandex yarn is controlled at 2.5-3.5 times and the yarn feed speed is controlled at 3.5-7.2 m / min.

6. The processing method of a high-sunlight-resistant, durable, UV-resistant knitted fabric according to claim 1, characterized in that, For non-white knitted fabrics, in step S3, acid dyes are used to dye the fabric, and lanthanum chloride is added to the working solution as a dyeing accelerator during the dyeing process.

7. The processing method of a high-sunlight-resistant, durable, UV-resistant knitted fabric according to claim 6, characterized in that, The acid dye is a type supplied by Huntsman Corporation. Products.

8. The processing method of a high-sunlight-resistant, durable, UV-resistant knitted fabric according to claim 6, characterized in that, The amount of lanthanum chloride added to the working solution is 0.5% to 1% of the fabric mass.

9. The processing method of a high-sunlight-resistant, durable, UV-resistant knitted fabric according to claim 1, characterized in that, For white knitted fabrics, in step S3, a nylon brightener is used to dye the fabric, wherein the nylon brightener is a stilbene derivative.

10. The processing method of a high-sunlight-resistant, durable, UV-resistant knitted fabric according to claim 1, characterized in that, In step S3, the setting and drying process involves heat setting at an overfeed rate of 3-10%, a machine speed of 18-25 m / min, and a temperature of 130-150°C to obtain a high-sunlight-resistant, durable, UV-resistant knitted fabric.