Anti-seepage preparation method of label fabric capable of being used for UV ink jet

Abstract

The invention belongs to the technical field of UV ink jet, and discloses an anti-seepage preparation method of a label fabric capable of being used for UV ink jet, and the anti-seepage preparation method comprises the following steps: S1, base material pretreatment and surface modification; s2, optimizing a formula of the anti-permeation UV printing ink; s3, precise jet printing and gradient photocuring are carried out; s4, post-treatment and performance strengthening; the pretreatment and surface modification of the base material comprise plasma activation of the base material and electrostatic spraying of a nano barrier layer. A three-dimensional network structure is constructed while the low-viscosity jet printing adaptability is maintained, the wicking effect caused by the capillary action is inhibited, synchronous crosslinking inside and outside an ink layer is achieved through differential energy input in the gradient curing process, the migration hidden danger of uncured monomers is eliminated, and the curing efficiency is improved. The problems of edge blurring and color diffusion caused by insufficient curing depth of traditional UV ink jet are solved from the source, and the technical chain breaks through the bottleneck of fiber surface suitability, so that jet printing patterns on complex texture fabrics have high precision and durability, and the industrial requirements of dynamic data identification are met.

Description

Technical Field

[0001] The present invention belongs to the technical field of UV inkjet, and specifically relates to a method for preventing ink leakage in the preparation of label fabrics for UV inkjet. Background Art

[0002] UV inkjet label fabrics are innovative textile identification solutions based on ultraviolet curing technology. By directly spraying UV ink on the fabric surface through a high-precision nozzle and instantaneously curing it, high-adhesion and weather-resistant labels are formed. Its core advantages lie in breaking through the limitations of traditional printing: using VOCs-free environmentally friendly ink, meeting the strict environmental protection standards of the textile industry, and significantly reducing production pollution; supporting resolutions above 600 dpi, enabling instant printing of clear patterns and dynamic data (such as QR codes, batch numbers) on complex texture surfaces such as cotton, linen, and chemical fibers; the cured labels have waterproof, wear-resistant, and anti-ultraviolet properties, withstanding repeated washing and outdoor environmental tests.

[0003] However, there are many deficiencies when performing UV inkjet on label fabrics. Specifically, insufficient curing depth leads to ink migration. UV inkjet instantaneously cures the ink through ultraviolet light, but its curing depth is limited by photoinitiators and ultraviolet focusing ability. When the ink is sprayed on fabrics with coarser textures, the ink may penetrate into different depths of the fibers, and some ink is outside the ultraviolet focusing plane and cannot be fully cured. The uncured ink will move or leak over time, resulting in blurred pattern edges, color diffusion, and even a leakage phenomenon similar to "fringes". There is a contradiction between ink viscosity and fabric permeability. UV inkjet needs to balance low viscosity (to ensure smooth printing) and high reactivity (rapid curing), but low-viscosity ink is prone to diffusion due to capillary action in fabrics with strong permeability (such as cotton and linen), exceeding the preset pattern boundary. For example, in thin or loose fabrics with large fiber gaps, the ink is prone to flow along the gaps, causing a "wicking effect" and resulting in leakage. There are limitations in the adaptability and adhesion of complex textures. Label fabrics are often made of blended or coarse-grained materials (such as linen and chemical fibers), and their uneven surfaces lead to uneven ink distribution. After UV curing, in some areas, the ink forms microcracks due to too small contact surfaces or curing shrinkage, reducing adhesion. Especially in high-temperature and high-humidity environments, the uncured ink layer is easily affected by physical friction or chemical erosion, accelerating leakage and peeling. Summary of the Invention

[0004] The purpose of the present invention is to provide a method for preventing ink leakage in the preparation of label fabrics for UV inkjet to solve the problems raised in the above background art.

[0005] To achieve the above purpose, the present invention provides the following technical solution: A method for preventing ink leakage in the preparation of label fabrics for UV inkjet, comprising the following steps: S1: Substrate pretreatment and surface modification; S2: Optimization of the anti-permeation UV ink formula; S3: precision printing and gradient light curing; S4: Post-processing and performance enhancement; The substrate pretreatment and surface modification include substrate plasma activation and electrostatic spraying of nano-barrier layer, the anti-penetration UV ink formula optimization includes resin base compounding and functional additive integration, the precision printing and gradient light curing include high-precision nozzle parameter setting and dual-band gradient curing process, and the post-treatment and performance enhancement include electron beam secondary cross-linking and perfluorosilicone hydrophobic film deposition.

[0006] Solve the problem of UV inkjet leakage on label fabrics through multi-dimensional collaborative innovation. After activation and modification, the surface of the substrate forms a highly active interface, which is combined with a nano-scale barrier layer to fill the fiber pores and effectively inhibit the lateral diffusion of the ink. The ink system is compounded with a low-viscosity, high-reactivity resin and a nano-filler to ensure the smoothness of printing while reducing the risk of capillary penetration. It is assisted by gradient photocuring to achieve rapid cross-linking of the surface layer and deep penetration curing, accurately balancing the curing depth and energy input. The back-end process uses a high-energy electron beam to enhance the density of the ink layer and construct an ultra-thin hydrophobic protective film, which significantly improves the weather resistance and resistance to physical and chemical corrosion of the label. The whole set of methods synergistically optimizes the three ends of substrate-ink-process, breaking through the bottlenecks of environmental protection, precision and durability of traditional printing, and can adapt to the high-resolution printing needs of complex fabric textures, meeting the stringent requirements for green and intelligent labels in the fields of clothing and industrial products.

[0007] As a further technical solution of the present invention, the substrate plasma activation includes using an atmospheric pressure plasma treatment system with a power set to 1.2 kW and an argon gas flow rate of 15 L / min, and performing surface activation for 120 seconds on a cotton / linen blended label fabric with a gram weight of 120±5 g / m². After treatment, X-ray photoelectron spectroscopy is used to confirm that the surface oxygen content is increased to more than 25%, and the contact angle is reduced to less than 30°, which meets the ASTM D5946 standard.

[0008] As a further technical solution of the present invention, the electrostatic spraying of the nano barrier layer includes uniformly spraying the modified nano silicon dioxide dispersion on the surface of the activated fabric at a coating amount of 0.8-1.2g / m², and the dispersion parameters include a particle size of 30±5nm and a solid content of 15%. After spraying, it is dried with hot air at 120°C to form a dense barrier layer with a thickness of 0.5-0.8μm, and the porosity is verified by scanning electron microscopy to be ≤5%.

[0009] Through the synergistic effect of plasma activation and nano-barrier layer spraying, the surface properties and anti-permeability ability of the label fabric are significantly improved. Plasma activation efficiently removes impurities on the fiber surface and introduces polar groups under specific process parameters, forming a highly active interface and enhancing the basis for ink adhesion; after the nano-silica dispersion is optimized by the spraying process, a dense physical barrier is constructed on the fabric surface, effectively closing the fiber gaps and blocking the ink penetration path. The synergistic effect of the activated hydrophilic surface and the nano-coating not only ensures the accurate positioning of the ink and avoids capillary diffusion, but also maintains the original flexibility and breathability of the fabric. This composite pretreatment process optimizes through both microstructure regulation and surface chemical modification, breaks through the adaptability limitations of traditional substrates to high-precision inkjet printing, provides a stable and reliable carrier for subsequent UV printing, realizes the permanent fixation of high-definition patterns on complex texture surfaces, and meets the industrial requirements for weather resistance and washability.

[0010] As a further technical solution of the present invention, the resin base material compounding includes mixing dicyclopentadiene acrylate monomer and polyurethane-modified epoxy acrylate oligomer in a mass ratio of 4:6. The former has a viscosity of 12 mPa·s, and the latter has a molecular weight of 2000 Da and a viscosity of 1500 mPa·s. 1.5% γ-aminopropyltriethoxysilane is added as a coupling agent and mixed for 30 minutes at a rotation speed of 800 rpm under a vacuum of -0.08 MPa by a planetary stirrer.

[0011] As a further technical solution of the present invention, the integration of the functional additives includes adding 5% nano-aerosil as an anti-permeability filler, with a specific surface area of 180 m² / g and a particle size of 15 nm, in combination with 0.3% polyether silane leveling agent and 2% photoinitiator TPO-L. Finally, the ink viscosity is controlled at 18 ± 2 mPa·s, and the surface tension is 28 ± 1 mN / m, which is verified by a Brookfield viscometer.

[0012] Through the integration of molecular design and multi-component synergy, a UV ink system with both low permeability and high printing suitability is constructed. The specific proportion compounding of dicyclopentadiene acrylate monomer and polyurethane-modified epoxy acrylate forms a resin skeleton with low viscosity and high reactivity, which not only ensures the smoothness of printing but also enhances the cohesive strength of the cured ink layer through double bond cross-linking; the introduction of the coupling agent strengthens the chemical bonding at the interface between the ink and the substrate, reducing the risk of interface peeling. Nano-aerosil, as a functional filler, forms a three-dimensional network structure in the ink by virtue of its high specific surface area characteristics, physically blocking the migration of the ink into the fiber gaps. At the same time, the synergistic effect of the leveling agent and the photoinitiator optimizes the spreading uniformity and curing efficiency of the ink. The viscosity and surface tension of the final ink are precisely regulated to ensure that the ink droplets achieve controllable wetting and rapid shaping on the fabric surface, suppressing leakage from the source of the formula and taking into account the requirements of high-precision pattern restoration and industrial durability.

[0013] As a further technical solution of the present invention, the setting of the high-precision nozzle parameters includes selecting the Ricoh MH5420M nozzle group, setting the minimum ink droplet to 3 pL, the ignition frequency to 50 kHz, the nozzle temperature to 25 ± 0.5 °C, the printing height is fixed at 0.8 mm, and the double closed-loop feedback system is used to ensure that the ink droplet positioning accuracy is ≤ 20 μm, and the printing line width error is ± 3%.

[0014] As a further technical solution of the present invention, the dual-band gradient curing process includes using a 365 nm UV-LED light source in the initial curing stage, with an irradiance of 2500 mW / cm² and an exposure time of 50 ms, so that the surface curing degree reaches more than 90%. In the deep curing stage, it switches to a 385 nm excimer lamp, with a pulse frequency of 200 Hz and an energy density of 800 mJ / cm², penetrating and curing the residual ink layer to a depth of ≥ 15 μm. The gradient curing ensures synchronous cross-linking inside and outside the ink, preventing the migration of uncured ink.

[0015] High-fidelity forming of the ink on the fabric surface is achieved through precise control and energy matching. The optimization of nozzle parameters combines ultra-fine droplet spraying and high-frequency response characteristics to ensure the accurate landing of ink droplets on the surface of complex fibers, avoiding ink flying or diffusion caused by mechanical vibration or temperature fluctuations. The dual-band light curing strategy uses different wavelength and energy configurations. The surface layer is quickly cross-linked to lock the pattern boundary, and the deep penetration curing eliminates unreacted monomers, blocking the longitudinal migration channel of the ink. This process system dynamically adjusts the curing rate and depth, balancing the printing efficiency and the structural stability of the ink layer, maintaining the flexibility of the fabric while endowing the ink with high density, effectively overcoming the surface shrinkage cracking and internal residue hidden dangers easily generated by traditional single-stage curing. The sequential coordination of printing and curing further reduces production energy consumption and adapts to the requirements of high-speed continuous operation.

[0016] As a further technical solution of the present invention, the electron beam secondary cross-linking includes irradiating and curing the ink layer with an electron beam of 10 MeV energy and 15 kGy dose. The hardness is increased to 3H through the ASTM D3363 standard test, and the cross-cut adhesion reaches the 5B grade. The electron beam can activate the residual double bonds of the resin and enhance the three-dimensional network density.

[0017] As a further technical solution of the present invention, the deposition of the perfluorosiloxane hydrophobic film includes generating a 50 nm thick perfluorosiloxane film layer on the surface of the cured ink layer through chemical vapor deposition process, the contact angle is increased to 115°, and the washability resistance exceeds 5000 cycles. It can block water vapor and chemical erosion and extend the durability of the label.

[0018] Through internal and external synergistic reinforcement, UV inkjet logos are given long-term protection and mechanical stability. Electron beam irradiation triggers deep cross-linking of the resin, reconstructs the three-dimensional network structure of the ink layer, significantly improves the hardness and interfacial bonding strength, and overcomes the risks of brittle cracking and falling off caused by traditional curing residues; the ultra-thin perfluorosilicone film covers the surface of the ink layer in a chemically bonded manner to form a low surface energy barrier, effectively blocking the penetration of water molecules and erosion by chemical media, while reducing the friction coefficient to resist physical wear. The synergistic effect of the two breaks through the durability bottleneck from the dual dimensions of microstructure reinforcement and surface protection, allowing the logo to maintain pattern clarity and color stability in extreme temperature and humidity, high-frequency cleaning or outdoor exposure environments. This process chain achieves balanced optimization of the internal and external performance of the ink layer through precise adaptation of material modification and energy regulation.

[0019] The beneficial effects of the present invention are as follows: 1. The present invention significantly improves the anti-penetration performance and pattern stability of label fabrics through the collaborative innovation of substrate pretreatment and ink system. The substrate surface is activated and modified to form a highly active interface. Combined with the physical barrier effect of the nano-coating, the fiber gaps are effectively closed and the risk of lateral diffusion of the ink is reduced. The composite design of the resin base material and the functional filler in the ink formula constructs a three-dimensional network structure while maintaining low-viscosity printing suitability, inhibiting the wicking effect caused by capillary action. The gradient curing process achieves synchronous cross-linking inside and outside the ink layer through differentiated energy input, eliminating the hidden danger of migration of uncured monomers, and solving the edge blur and color diffusion problems caused by insufficient curing depth in traditional UV inkjet from the source. This technology chain breaks through the bottleneck of fiber surface adaptability, so that the printed patterns on complex textured fabrics have both high precision and durability, meeting the industrialization needs of dynamic data identification.

[0020] 2. The present invention promotes the upgrading of UV inkjet label fabrics towards high reliability through the integrated application of precision printing and post-processing strengthening technology. The combination of high-precision nozzle parameters and dynamic feedback system ensures the precise positioning of micron-level ink droplets on rough surfaces and avoids ink flying defects caused by mechanical vibration or temperature fluctuations. The dual-band gradient curing strategy takes into account both rapid surface shaping and deep penetration cross-linking through the timing regulation of wavelength and energy, greatly improving the uniformity of the ink layer structure. The electron beam secondary cross-linking technology further strengthens the three-dimensional network density of the resin and gives the ink layer excellent mechanical strength and adhesion. The ultra-thin hydrophobic film layer forms a long-lasting protective barrier through chemical bonding to block water vapor erosion and physical wear. The process system forms a closed-loop optimization from printing accuracy, curing depth to durability.

[0021] 3. By adopting low-energy plasma activation to replace chemical cleaning, selecting solvent-free environmental protection materials for both the nano-coating and the ink system, the present invention significantly reduces VOCs emissions. The electron beam cross-linking and UV curing processes reduce heat loss through precise energy regulation, in line with the trend of low-carbon manufacturing. At the same time, this method is compatible with automated production line integration, supports flexible switching from single-piece customization to mass production, realizes real-time optimization of process parameters through the Internet of Things, and improves resource utilization rate. This multi-dimensional innovation in technology, environmental protection, and efficiency not only solves the problems of traditional inkjet leakage and pollution but also promotes the transformation of textile labels towards the direction of green intelligence, providing a scalable high-quality printing technology path for the industry. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 is a schematic diagram of the overall process of the present invention; Figure 2 is a schematic diagram of the substrate pretreatment and surface modification process of the present invention; Figure 3 is a schematic diagram of the process for optimizing the formulation of the anti-permeation UV ink of the present invention; Figure 4 is a schematic diagram of the precision printing and gradient light curing process of the present invention; Figure 5 is a schematic diagram of the post-treatment and performance enhancement process of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0023] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0024] As Figures 1 to 5 shown, in the embodiments of the present invention, a method for preparing an anti-permeation label fabric for UV inkjet includes the following steps: S1: Substrate pretreatment and surface modification; S2: Optimization of the formulation of the anti-permeation UV ink; S3: Precision printing and gradient light curing; S4: Post-treatment and performance enhancement; The substrate pretreatment and surface modification include substrate plasma activation and electrostatic spraying of a nano-barrier layer. The optimization of the formulation of the anti-permeation UV ink includes the compounding of resin bases and the integration of functional additives. The precision printing and gradient light curing include the setting of high-precision nozzle parameters and a dual-band gradient curing process. The post-treatment and performance enhancement include electron beam secondary cross-linking and the deposition of a perfluorosiloxane hydrophobic film.

[0025] Solving the problem of UV inkjet leakage in label fabrics through multi-dimensional collaborative innovation. After the surface of the substrate is activated and modified, a highly active interface is formed. Combining with a nano-barrier layer to fill the fiber pores effectively inhibits the lateral diffusion of the ink. The ink system reduces the risk of capillary penetration while ensuring smooth printing through the compounding of a low-viscosity and highly reactive resin and nano-fillers, supplemented by gradient light curing to achieve rapid surface cross-linking and deep penetration curing, precisely balancing the curing depth and energy input. The subsequent process uses high-energy electron beams to enhance the density of the ink layer and constructs an ultra-thin hydrophobic protective film, significantly improving the weather resistance and the ability to resist physical and chemical erosion of the label. The whole method optimizes the substrate-ink-process from three aspects, breaks through the bottlenecks of environmental protection, precision, and durability of traditional printing, can adapt to the high-resolution printing requirements of complex fabric textures, and meets the strict requirements for green intelligent labels in fields such as clothing and industrial products.

[0026] As Figure 2 shown, the plasma activation of the substrate includes using an atmospheric pressure plasma treatment system, setting the power at 1.2 kW and the argon flow rate at 15 L / min, and performing 120-second surface activation on a cotton / flax blended label fabric with a gram weight of 120 ± 5 g / m². After treatment, it is confirmed by X-ray photoelectron spectroscopy that the surface oxygen element content has increased to more than 25% and the contact angle has decreased to less than 30°, meeting the ASTM D5946 standard. The electrostatic spraying of the nano-barrier layer includes uniformly spraying a modified nano-silica dispersion liquid on the surface of the activated fabric at a coating amount of 0.8 - 1.2 g / m². The parameters of the dispersion liquid include a particle size of 30 ± 5 nm and a solid content of 15%. After spraying, a dense barrier layer with a thickness of 0.5 - 0.8 μm is formed by hot air drying at 120 °C, and the porosity is verified by scanning electron microscopy to be ≤ 5%.

[0027] Through the synergistic effect of plasma activation and nano-barrier layer spraying, the surface performance and anti-permeability of the label fabric are significantly improved. Plasma activation efficiently removes impurities on the fiber surface and introduces polar groups under specific process parameters, forming a highly active interface and enhancing the basis for ink adhesion. After the nano-silica dispersion liquid is optimized in the spraying process, a dense physical barrier is constructed on the fabric surface, effectively closing the fiber gaps and blocking the ink penetration path. The synergistic effect of the activated hydrophilic surface and the nano-coating not only ensures the precise positioning of the ink but also avoids capillary diffusion, while maintaining the original flexibility and breathability of the fabric. This composite pretreatment process breaks through the adaptability limitations of traditional substrates to high-precision inkjet through dual optimization of microstructure regulation and surface chemical modification, provides a stable and reliable carrier for subsequent UV printing, realizes the permanent fixation of high-definition patterns on complex texture surfaces, and meets the industrial requirements for weather resistance and washability.

[0028] As Figure 3As shown, the resin base compounding includes mixing dicyclopentadiene acrylate monomer and polyurethane-modified epoxy acrylate oligomer in a mass ratio of 4:6. The former has a viscosity of 12 mPa·s, and the latter has a molecular weight of 2000 Da and a viscosity of 1500 mPa·s. 1.5% γ-aminopropyltriethoxysilane is added as a coupling agent and mixed for 30 minutes at a rotation speed of 800 rpm under a vacuum of -0.08 MPa by a planetary stirrer. The functional additive integration includes adding 5% nano-aerosil as an anti-permeation filler, with a specific surface area of 180 m² / g and a particle size of 15 nm, in combination with 0.3% polyether silane leveling agent and 2% photoinitiator TPO-L. Finally, the ink viscosity is controlled at 18 ± 2 mPa·s, and the surface tension is 28 ± 1 mN / m, which is verified by a Brookfield viscometer.

[0029] By integrating through molecular design and multi-component synergy, a UV ink system with both low permeability and high printing suitability is constructed. The specific ratio compounding of dicyclopentadiene acrylate monomer and polyurethane-modified epoxy acrylate forms a resin skeleton with low viscosity and high reactivity, which not only ensures the smoothness of inkjet printing but also enhances the cohesive strength within the cured ink layer through double-bond crosslinking. The introduction of the coupling agent strengthens the chemical bonding at the interface between the ink and the substrate, reducing the risk of interface peeling. Nano-aerosil, as a functional filler, forms a three-dimensional network structure in the ink by virtue of its high specific surface area characteristics, physically blocking the migration of the ink into the fiber gaps. At the same time, the synergistic effect of the leveling agent and the photoinitiator optimizes the spreading uniformity and curing efficiency of the ink. The viscosity and surface tension of the final ink are precisely regulated to ensure that the ink droplets achieve controllable wetting and rapid shaping on the fabric surface, suppressing leakage from the source of the formula and taking into account the requirements of high-precision pattern reproduction and industrial-grade durability.

[0030] As Figure 4 shown, the high-precision nozzle parameters setting includes selecting Ricoh MH5420M nozzle group, setting the minimum ink droplet at 3 pL, the firing frequency at 50 kHz, the nozzle hole temperature at 25 ± 0.5 °C, the printing height fixed at 0.8 mm, and ensuring the ink droplet positioning accuracy ≤ 20 μm and the printing line width error ± 3% through a double-closed-loop feedback system. The double-band gradient curing process includes using a 365 nm UV-LED light source in the initial curing stage, with an irradiance of 2500 mW / cm² and an exposure time of 50 ms, so that the surface curing degree reaches more than 90%. In the deep curing stage, it switches to a 385 nm excimer lamp, with a pulse frequency of 200 Hz and an energy density of 800 mJ / cm², penetrating and curing the residual ink layer to a depth of ≥ 15 μm. The gradient curing ensures the synchronous crosslinking inside and outside the ink, preventing the migration of uncured ink.

[0031] High-fidelity forming of ink on the fabric surface is achieved through precise control and energy matching. The optimization of nozzle parameters combines ultra-fine droplet spraying and high-frequency response characteristics to ensure the precise landing of ink droplets on the surface of complex fibers, avoiding ink splashing or diffusion caused by mechanical vibration or temperature fluctuations; the dual-band light-curing strategy adopts different wavelength and energy configurations. The surface layer is quickly cross-linked to lock the pattern boundary, and the deep penetration curing eliminates unreacted monomers, blocking the longitudinal migration channel of the ink. This process system balances the printing efficiency and the structural stability of the ink layer by dynamically adjusting the curing rate and depth, maintaining the flexibility of the fabric while endowing the ink with high density, effectively overcoming the surface shrinkage cracking and internal residue problems easily generated by traditional single-stage curing. The timing coordination of printing and curing further reduces production energy consumption and adapts to the requirements of high-speed continuous operation.

[0032] As Figure 5 shown, the electron beam secondary cross-linking includes irradiating and curing the ink layer with an electron beam of 10 MeV energy and 15 kGy dose. The hardness is increased to 3H through the ASTM D3363 standard test, and the cross-hatch adhesion reaches grade 5B. The electron beam can activate the residual double bonds of the resin and enhance the three-dimensional network density. The deposition of the perfluorosiloxane hydrophobic film includes generating a 50-nm-thick perfluorosiloxane film layer on the surface of the cured ink layer through chemical vapor deposition. The contact angle is increased to 115°, and the washability exceeds 5000 cycles, which can block water vapor and chemical erosion and extend the durability of the label.

[0033] Through the internal and external synergistic strengthening, long-term protection and mechanical stability are given to the UV inkjet label. Electron beam irradiation triggers deep cross-linking of the resin, reconstructing the three-dimensional network structure of the ink layer, significantly improving the hardness and interfacial bonding strength, and overcoming the risks of brittle cracking and peeling caused by traditional curing residues; the ultra-thin perfluorosiloxane film covers the surface of the ink layer in a chemical bonding manner, forming a low-surface-energy barrier, effectively blocking the penetration of water molecules and chemical medium erosion, and at the same time reducing the friction coefficient to resist physical wear. The synergistic effect of the two breaks through the durability bottleneck from the dual dimensions of microstructural reinforcement and surface protection, enabling the label to maintain pattern clarity and color stability under extreme temperature and humidity, high-frequency cleaning or outdoor exposure environments. This process chain realizes the balanced optimization of the internal and external properties of the ink layer through the precise adaptation of material modification and energy regulation.

[0034] Through the collaborative innovation of substrate pretreatment and ink system, the anti-penetration performance and pattern stability of label fabrics are significantly improved. The substrate surface is activated and modified to form a highly active interface. Combined with the physical barrier effect of the nano-coating, the fiber gaps are effectively closed and the risk of lateral diffusion of the ink is reduced. The compound design of the resin base material and the functional filler in the ink formula builds a three-dimensional network structure while maintaining low-viscosity printing suitability, inhibiting the wicking effect caused by capillary action. The gradient curing process achieves synchronous cross-linking inside and outside the ink layer through differentiated energy input, eliminating the hidden danger of migration of uncured monomers, and solving the edge blur and color diffusion problems caused by insufficient curing depth of traditional UV inkjet from the source. This technology chain breaks through the bottleneck of fiber surface adaptability, so that the printed patterns on complex textured fabrics have both high precision and durability, meeting the industrialization needs of dynamic data identification.

[0035] Through the integrated application of precision printing and post-processing enhancement technology, UV inkjet label fabrics are promoted to upgrade to high reliability. The combination of high-precision nozzle parameters and dynamic feedback system ensures the precise positioning of micron-level ink droplets on rough surfaces, avoiding ink flying defects caused by mechanical vibration or temperature fluctuations. The dual-band gradient curing strategy controls the timing of wavelength and energy, taking into account both rapid surface shaping and deep penetration cross-linking, greatly improving the uniformity of the ink layer structure. The electron beam secondary cross-linking technology further enhances the three-dimensional network density of the resin, giving the ink layer excellent mechanical strength and adhesion. The ultra-thin hydrophobic film layer forms a long-term protective barrier through chemical bonding to block water vapor erosion and physical wear. The process system forms a closed-loop optimization from printing accuracy, curing depth to durability.

[0036] By adopting low-energy plasma activation instead of chemical cleaning, both nano-coating and ink systems use solvent-free and environmentally friendly materials, which significantly reduces VOCs emissions. The electron beam cross-linking and UV curing processes reduce heat loss through precise energy control, which is in line with the trend of low-carbon manufacturing. At the same time, this method is compatible with automated production line integration and supports flexible switching from single-piece customization to mass production. It realizes real-time optimization of process parameters through the Internet of Things and improves resource utilization. This multi-dimensional innovation of technology, environmental protection and efficiency not only solves the problems of traditional inkjet leakage and pollution, but also promotes the transformation of textile labels towards green and intelligent directions, providing the industry with a scalable high-quality printing technology path.

[0037] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A method for preparing a label fabric resistant to seepage for UV inkjet, characterized in that: It includes the following steps: S1: Substrate pretreatment and surface modification; S2: Optimization of the anti-permeation UV ink formulation; S3: Precision printing and gradient photocuring; S4: Post-treatment and performance enhancement; The substrate pretreatment and surface modification include substrate plasma activation and electrostatic spraying of a nano-barrier layer. The optimization of the anti-permeation UV ink formulation includes resin matrix compounding and integration of functional additives. The precision printing and gradient photocuring include setting high-precision nozzle parameters and a dual-band gradient curing process. The post-treatment and performance enhancement include electron beam secondary crosslinking and deposition of a perfluorosiloxane hydrophobic film.

2. The anti-seepage preparation method of a label fabric applicable to UV inkjet according to claim 1, characterized in that: The substrate plasma activation includes using an atmospheric pressure plasma treatment system, setting the power at 1.2 kW and the argon flow rate at 15 L / min, and performing 120-second surface activation on a cotton / linen blended label fabric with a grammage of 120 ± 5 g / m². After treatment, it is confirmed by X-ray photoelectron spectroscopy that the surface oxygen element content is increased to more than 25% and the contact angle is reduced to less than 30°, meeting the ASTM D5946 standard.

3. The anti-seepage preparation method of a label fabric applicable to UV inkjet according to claim 1, characterized in that: The electrostatic spraying of the nano-barrier layer includes uniformly spraying a modified nano-silica dispersion liquid on the surface of the activated fabric at a coating amount of 0.8 - 1.2 g / m². The dispersion liquid parameters include a particle size of 30 ± 5 nm and a solid content of 15%. After spraying, it is dried by hot air at 120°C to form a dense barrier layer with a thickness of 0.5 - 0.8 μm, and the porosity is verified by scanning electron microscopy to be ≤ 5%.

4. The anti-seepage preparation method of a label fabric applicable to UV inkjet according to claim 1, characterized in that: The resin matrix compounding includes mixing dicyclopentadiene acrylate monomer and polyurethane-modified epoxy acrylate oligomer in a mass ratio of 4:

6. The former has a viscosity of 12 mPa·s, and the latter has a molecular weight of 2000 Da and a viscosity of 1500 mPa·s. 1.5% γ-aminopropyltriethoxysilane is added as a coupling agent and mixed for 30 minutes at a rotation speed of 800 rpm under a vacuum of -0.08 MPa by a planetary stirrer.

5. The anti-seepage preparation method of a label fabric applicable to UV inkjet according to claim 1, characterized in that: The integration of functional additives includes adding 5% nano-aerosil as an anti-permeation filler, with a specific surface area of 180 m² / g and a particle size of 15 nm, in combination with 0.3% polyether silane leveling agent and 2% photoinitiator TPO-L. Finally, the ink viscosity is controlled at 18 ± 2 mPa·s and the surface tension is 28 ± 1 mN / m, which is verified by a Brookfield viscometer.

6. The anti-seepage preparation method of a label fabric applicable to UV inkjet according to claim 1, characterized in that: The setting of high-precision nozzle parameters includes selecting a Ricoh MH5420M nozzle group, setting the minimum ink droplet at 3 pL, the ignition frequency at 50 kHz, the nozzle hole temperature at 25 ± 0.5°C, and the printing height fixed at 0.8 mm. The dual closed-loop feedback system is used to ensure that the ink droplet positioning accuracy is ≤ 20 μm and the printing line width error is ± 3%.

7. A method for preventing seepage of a label fabric applicable to UV inkjet according to claim 1, characterized in that: The dual-band gradient curing process includes using a 365 nm UV-LED light source in the initial curing stage, with an irradiance of 2500 mW / cm² and an exposure time of 50 ms, to make the surface curing degree reach more than 90%. In the deep curing stage, it is switched to a 385 nm excimer lamp, with a pulse frequency of 200 Hz and an energy density of 800 mJ / cm², to penetrate and cure the residual ink layer to a depth of ≥ 15 μm. The gradient curing ensures synchronous crosslinking inside and outside the ink and prevents the migration of uncured ink.

8. A method for preventing seepage of a label fabric applicable to UV inkjet according to claim 1, characterized in that: The electron beam secondary cross-linking includes irradiating and curing the ink layer with an electron beam having an energy of 10 MeV and a dose of 15 kGy. The hardness is increased to 3H through the ASTM D3363 standard test, and the cross-hatch adhesion reaches the 5B grade. The electron beam can activate the residual double bonds of the resin and enhance the three-dimensional network density.

9. The anti-seepage preparation method of a label fabric applicable to UV inkjet according to claim 1, characterized in that: The deposition of the perfluorosiloxane hydrophobic film includes generating a 50-nm-thick perfluorosiloxane film layer on the surface of the cured ink layer through a chemical vapor deposition process. The contact angle is increased to 115°, and the washability resistance exceeds 5000 cycles. It can block water vapor and chemical erosion and extend the durability of the label.

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