Multi-color adhesive-edge-free heat transfer printing technology

Abstract

The multicolor adhesive-edge-free heat transfer printing technology comprises the following steps that S1, a composite release film is prepared, and a release surface comprises a bottom layer printing area A, a pattern printing area B and an adhesive layer bearing area C of which the release force is sequentially increased; s2, the area A is coated with waterborne polyurethane-acrylic acid hybrid bottom layer slurry, hot air drying and ultraviolet light curing are sequentially carried out, and a high-elastic bottom layer is formed; s3, carrying out multicolor overprinting on the B area by using at least two aqueous slurries in nano pigment dispersion liquid, and immediately carrying out photocuring after each color is printed; s4, the pattern layer of the area C is coated with water-based bonding slurry, and pre-drying is carried out; and S5, the treated transfer printing film and the fabric are overlapped for transfer printing, the release film is torn off after cooling, and the multicolor adhesive-edge-free transfer printing product is obtained. According to the sectional type multicolor printing curing process, the multicolor transfer printing effect of high performance, high environmental protection performance and high water resistance is achieved.

Description

Technical Field

[0001] This invention relates to the field of heat transfer technology, specifically a multi-color, adhesive-free heat transfer technology. Background Technology

[0002] Heat transfer printing technology is widely used in the garment industry due to its flexible pattern design and high production efficiency. However, traditional multi-color heat transfer printing technology has many insurmountable drawbacks. For example, there is the problem of adhesive edges. When multiple layers of ink and hot melt adhesive are superimposed, the molten adhesive easily overflows from the edge of the pattern during hot pressing, forming hardened adhesive edges, which seriously affects the appearance and feel. Secondly, it has poor elasticity and washability. The multi-layer structure restricts the natural stretchability of the fabric, making it prone to cracking and peeling after repeated washing and stretching. In addition, there are difficulties in color registration and low color saturation. When printing multiple colors, if the bottom layer of ink is not completely dry, it will affect the printing of the upper layer, resulting in inaccurate registration and muddy colors. Furthermore, it poses environmental risks. In order to pursue adhesion and color, solvent-based inks and adhesives containing formaldehyde and phthalates are often used, which do not comply with environmental regulations.

[0003] Existing technologies, such as CN111038079B, provide a water-based adhesive-free heat transfer process. However, this is mainly for monochrome or color block heat transfer, and its process and formulation cannot solve the problems of interlayer interference, color overlay, composite elasticity, and water resistance matching caused by multi-color overprinting. Multi-color transfer is not a simple color overlay, but a complex systemic problem that requires collaborative and innovative design of substrates, inks, adhesives, and processes. Summary of the Invention

[0004] This application provides a multi-color adhesive-free edge heat transfer technology and designs a segmented multi-color printing and curing process, achieving high performance, high environmental friendliness, and high water resistance in multi-color transfer printing.

[0005] This application provides a multi-color adhesive-free heat transfer printing technology, comprising the following steps: S1: preparing a composite release film, the release surface including a bottom printing area A, a pattern printing area B, and an adhesive layer bearing area C with progressively increasing release forces; S2: coating the A area with an aqueous polyurethane-acrylic hybrid bottom layer paste, and sequentially performing hot air drying and ultraviolet curing to form a highly elastic bottom layer; S3: on the B area, using at least two types of aqueous paste from a nano-pigment dispersion for multi-color overprinting, with each color immediately cured after printing; S4: coating the pattern layer in the C area with an aqueous adhesive paste containing low-temperature responsive components and high-temperature responsive components, and pre-drying; S5: stacking the treated transfer film with a fabric for transfer printing, and peeling off the release film after cooling to obtain a multi-color adhesive-free transfer printed product.

[0006] By adopting the above technical solution, this application first uses the conventional method of partition coating and ultraviolet curing to prepare a high-performance gradient release film, then uses a multi-color printing process to fundamentally eliminate color mixing, and finally designs a dual adhesive system to control the flow and curing of the adhesive, thereby achieving a high-performance and environmentally friendly multi-color transfer printing effect.

[0007] Preferably, in step S1, low-energy UV-curable silicone oil is coated onto the PET base film in multiple layers using a gravure coating method, and zone control is achieved through differentiated UV curing energy; the coating amount in area A is 0.8 g / m², the UV curing energy is 120 mJ / cm², and the release force in area A is 0.03 N / 25mm; the UV curing energy for the second coating in area B is 240 mJ / cm², and the release force in area B is 0.08 N / 25mm; the UV curing energy for the third coating in area C is 400 mJ / cm², and the release force in area C is 0.35 N / 25mm.

[0008] By employing the above technical solution, the crosslinking density of the silicone layer can be precisely controlled by adjusting two conventional parameters: coating amount (film thickness) and UV curing energy. Lower coating amount and lower curing energy result in lower crosslinking density and weaker release force; conversely, higher coating amount and higher curing energy result in stronger release force. This method requires no special equipment and exhibits excellent repeatability.

[0009] Preferably, in step S2, the waterborne polyurethane-acrylic hybrid underlayer slurry comprises the following components in parts by weight: waterborne polyurethane dispersion: 60-80 parts; waterborne self-crosslinking acrylic emulsion: 20-40 parts; nano-sized colloidal silica: 5-10 parts; and ultraviolet cationic photoinitiator: 1-2 parts.

[0010] Preferably, in step S2, the hot air drying conditions are: temperature 75-85℃, time 80-100 seconds; the ultraviolet curing conditions are: using a 254nm short-wave ultraviolet lamp, energy 120-180 mJ / cm².

[0011] By adopting the above technical solution, short-wave UV light in this application can efficiently excite the photoinitiator on the surface, causing the acrylic component on the surface to crosslink rapidly, forming a dense "shell," while the internal polyurethane remains in a highly elastic state, constituting the "core." This hard shell can completely prevent the penetration and re-swelling of moisture during subsequent printing.

[0012] Preferably, in step S3, the aqueous slurry is prepared by online mixing of aqueous photosensitive binder and nano pigment dispersion at a weight ratio of (7-9):(1-3).

[0013] Preferably, the pigment particle size D90 of the nano-pigment dispersion is < 150nm, and the solid content is 35-45%; the water-based photosensitive binder is a photosensitive water-based acrylic resin with double bonds grafted onto its molecular chain, and contains 2-4% photoinitiator.

[0014] Preferably, in step S3, the photocuring conditions are: drying at 70-75°C for 25-35 seconds using mid-wave infrared light, followed by curing with a 395nm ultraviolet LED lamp at an energy of 800-1200 mJ / cm²; the curing energy for the final color is not less than 1000 mJ / cm².

[0015] By adopting the above technical solution, this application cures each color layer with ultra-high energy UV light after printing, causing the color layer to rapidly transform from a soluble state into a completely insoluble and infusible cross-linked network. The layers are purely physically stacked, reducing the probability of color mixing and ensuring the purity and saturation of the colors.

[0016] Preferably, in step S4, the aqueous adhesive slurry comprises the following components in parts by weight: ethylene-acrylic acid copolymer emulsion (EAA): 55-65 parts; microencapsulated blocked isocyanate: 6-10 parts; organobentonite: 3-5 parts; film-forming aid: 1-3 parts.

[0017] Preferably, in step S4, the pre-drying conditions are: temperature 85-95°C, time 8-12 minutes.

[0018] By employing the above technical solutions, the ethylene-acrylic acid copolymer emulsion can melt and flow at relatively low temperatures, providing initial adhesion; the microencapsulated crosslinking agent is activated only at higher temperatures, providing final durability. Organobentonite provides excellent thixotropy and forms a gel network upon standing, preventing flow.

[0019] Preferably, in step S5, the heat pressing process parameters for transferring the transfer film to the fabric are as follows: flow penetration stage: temperature 90-100℃, pressure 0.4-0.6 MPa, time 8-12 seconds; crosslinking trigger stage: temperature 125-135℃, pressure 0.7-0.9 MPa, time 12-18 seconds; setting and stabilizing stage: temperature 125-135℃, pressure 0.1-0.3 MPa, time 5-10 seconds.

[0020] By employing the above technical solution, in the heat pressing process of transferring the transfer film onto the fabric, the flow penetration stage involves the temperature initially rising above the melting point of the ethylene-acrylic acid copolymer emulsion but below the crosslinking agent's desealing temperature. At this point, the ethylene-acrylic acid copolymer emulsion melts, the viscosity of the adhesive system drops sharply, and it fully penetrates the fabric fibers under pressure. Then, in the crosslinking triggering stage, the temperature jumps above the microcapsule desealing temperature. The microcapsules rupture, isocyanates are released, and they undergo a rapid crosslinking reaction with the carboxyl groups on the ethylene-acrylic acid copolymer and the active groups on the fabric fibers. The pressure increases to its maximum, promoting the crosslinking reaction and mechanical interlocking.

[0021] Finally, in the stabilization phase, the pressure is rapidly reduced to a maintenance value. During this stage, the cross-linking reaction tends to be complete, and the melt viscosity rapidly recovers due to cross-linking. The pressure reduction process allows internal stress to be released, and the cross-linked network and the reformed bentonite gel network work together to fix the adhesive within the patterned area. After pressing, the sample is cooled to room temperature. Utilizing the release force difference, a single, complete peel can be easily achieved, resulting in a transfer pattern with clear edges and no adhesive residue.

[0022] One or more technical solutions provided in this application have at least the following technical effects or advantages: 1. This application first uses the conventional method of partition coating and UV curing to prepare a high-performance gradient release film, then uses a multi-color printing process to fundamentally eliminate color mixing, and finally designs a dual adhesive system to control the flow and curing of the adhesive, thereby achieving a high-performance and environmentally friendly multi-color transfer printing effect.

[0023] 2. This application precisely controls the crosslinking density of the silicone layer by controlling two conventional parameters: coating amount (film thickness) and UV curing energy. A lower coating amount and lower curing energy result in a lower crosslinking density and weaker release force; conversely, a higher coating amount results in a stronger release force. This method requires no special equipment and has excellent repeatability.

[0024] 3. In this application, short-wave UV light can efficiently excite the photoinitiator on the surface, causing the acrylic component on the surface to crosslink rapidly, forming a dense "shell," while the internal polyurethane remains in a highly elastic state, forming the "core." This hard shell can completely prevent the penetration and re-swelling of moisture during subsequent printing. Attached Figure Description

[0025] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0026] Figure 1The wash resistance test tables for Embodiments 1 and 4 of this application are provided.

[0027] Figure 2 These are test samples for the wash resistance test of Examples 1 and 4 of this application. Detailed Implementation

[0028] This application provides a multi-color adhesive-free edge heat transfer technology and designs a segmented multi-color printing and curing process, achieving a high-performance and environmentally friendly multi-color transfer effect.

[0029] The technical solutions in the embodiments of this application will be clearly and completely described below with reference to the embodiments of this application. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0030] It should be noted that the terms "first," "second," etc., used in the specification and claims of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of this application described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or server that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or modules not explicitly listed or inherent to such processes, methods, products, or devices. Example 1

[0031] This application provides a preparation process for a multi-color, adhesive-free heat transfer printing technology, the specific steps of which are as follows: S1. Using a gravure coating machine, apply low-energy UV-curable silicone oil to a 50μm thick PET base film, and perform coating and curing treatment according to the following areas.

[0032] Area A (bottom printing area): Coating was performed using a gravure roller with a cell depth of 30 μm at a coating amount of 0.8 g / m², followed by curing with a UV lamp with a main wavelength of 365 nm and an energy of 120 mJ / cm². The release force after curing was measured to be 0.03 N / 25 mm.

[0033] Area B (Pattern Printing Area): Based on Area A, a gravure roller with a cell depth of 20 μm is used for localized overcoating, with a coating amount of approximately 0.5 g / m². This is then cured using the same UV lamp at an energy of 240 mJ / cm². The release force after curing was measured to be 0.06 N / 25 mm.

[0034] Area C (Adhesive Layer Bearing Area): Based on Area B, a gravure roller with a cell depth of 35 μm is used to coat a specific area at a coating amount of approximately 1.2 g / m², followed by curing with the same UV lamp at an energy of 400 mJ / cm². The release force after curing was measured to be 0.35 N / 25 mm.

[0035] S2. In area A of the release film, a high-elastic water-based undercoat slurry is coated using a microgravure coating method. The wet weight of the coating is controlled at 45 g / m². After coating, it is dried, first under circulating hot air at 80°C for 90 seconds; then immediately cured by irradiation with a 254nm short-wave ultraviolet lamp at an energy of 150 mJ / cm² to form the high-elastic undercoat.

[0036] S3. In area B of the release film, two-color overprinting is performed using a 200-mesh screen. Each color paste is prepared online by mixing water-based photosensitive binder and nano-pigment dispersion at a weight ratio of 8:2. Specifically, the first color (blue) is printed by immediately passing it through a curing channel, first drying it at 70℃ with mid-wave infrared light for 30 seconds, and then curing it with a 395nm UV LED lamp at an energy of 1000 mJ / cm². The second color (black) is printed and cured by overprinting a black pattern on top of the second color, first drying it at 75℃ with mid-wave infrared light for 40 seconds, and then curing it with a 395nm+365nm dual-wavelength UV LED lamp at an energy of 1200 mJ / cm².

[0037] S4. Apply water-based adhesive paste to area C of the release film using an extrusion coater. After coating, place the transfer film in a 90°C circulating hot air oven to dry for 10 minutes to obtain a dried adhesive layer.

[0038] S5. Cut the prepared transfer film and place it, pattern side down, onto a 95% cotton / 5% spandex knitted fabric. Use a flatbed heat press for the transfer. The heat press program is set as follows: Flow penetration stage: temperature 95℃, pressure 0.5 MPa, time 10 seconds. Crosslinking trigger stage: temperature 130℃, pressure 0.8 MPa, time 15 seconds. Setting and stabilization stage: temperature 130℃, pressure linearly decreases to 0.2 MPa within 3 seconds and is maintained for 5 seconds.

[0039] After the heat pressing is complete, allow the transfer print to cool naturally to room temperature (below 25°C). Then, hold one corner of the release film and gently peel it off at a 45° angle. The release film is completely peeled off, and all the pattern layers and adhesive layers are transferred to the fabric as a whole, resulting in a multi-color transfer pattern with clear, sharp edges, no glue edges, and a soft feel.

[0040] Specifically, the high-elasticity waterborne base slurry in step S2 consists of the following components by weight: waterborne polyurethane dispersion (Tg=-35℃): 70 parts; waterborne self-crosslinking acrylic emulsion (Tg=+20℃): 30 parts; nano-sized colloidal silica (AEROSIL® 200): 8 parts; ultraviolet cationic photoinitiator (sulfonate CPI-210S): 1.5 parts; deionized water: 15 parts.

[0041] The waterborne photosensitive binder in step S3 is prepared by adding 3% photoinitiator (I-819) to waterborne acrylic resin (Setalux® 1171).

[0042] The nano-pigment dispersions in step S3 are black and blue, respectively, with a solid content of 40% and a pigment particle size D90 < 150 nm. In Example 1 of this application, the nano-pigment dispersions are bicolor, consisting of black and blue.

[0043] The aqueous adhesive slurry in step S4 consists of the following components by weight: ethylene-acrylic acid copolymer emulsion (EAA, melting point 85°C): 60 parts; microencapsulated blocked isocyanate (unsealing temperature 125°C): 8 parts; organobentonite (rheology control agent): 4 parts; dipropylene glycol butyl ether (film-forming aid): 2 parts; deionized water: 25 parts. Specifically, in the aqueous adhesive slurry, the ethylene-acrylic acid copolymer emulsion is the low-temperature responsive component, the microencapsulated blocked isocyanate is the high-temperature responsive component, the organobentonite is the rheology control agent, and the dipropylene glycol butyl ether is the film-forming aid. The ethylene-acrylic acid copolymer emulsion melts and flows at relatively low temperatures, providing initial adhesion; the microencapsulated crosslinking agent is activated at higher temperatures, providing final durability. The organobentonite provides excellent thixotropy and forms a gel network upon standing, preventing flow. Example 2

[0044] The difference between Example 2 and Example 1 is that the proportions of the high-elastic water-based underlayer slurry and the water-based adhesive slurry are different.

[0045] The high-elasticity waterborne base slurry in step S2 consists of the following components by weight: waterborne polyurethane dispersion (Tg=-35℃): 60 parts; waterborne self-crosslinking acrylic emulsion (Tg=+20℃): 20 parts; nano-sized colloidal silica (AEROSIL® 200): 5 parts; ultraviolet cationic photoinitiator (sulfonate CPI-210S): 1 part; deionized water: 10 parts.

[0046] The aqueous adhesive slurry in step S4, by weight, consists of the following components: ethylene-acrylic acid copolymer emulsion (EAA, melting point 85°C): 55 parts; microencapsulated blocked isocyanate (unsealing temperature 125°C): 6 parts; organobentonite (rheology control agent): 3 parts; dipropylene glycol butyl ether (film-forming aid): 1 part; deionized water: 20 parts. Example 3

[0047] The difference between Example 3 and Example 1 is that the proportions of the high-elastic water-based underlayer slurry and the water-based adhesive slurry are different.

[0048] The high-elasticity waterborne base slurry in step S2 consists of the following components by weight: waterborne polyurethane dispersion (Tg=-35℃): 80 parts; waterborne self-crosslinking acrylic emulsion (Tg=+20℃): 40 parts; nano-sized colloidal silica (AEROSIL® 200): 10 parts; ultraviolet cationic photoinitiator (sulfonate CPI-210S): 2 parts; deionized water: 20 parts.

[0049] The aqueous adhesive slurry in step S4 consists of the following components by weight: ethylene-acrylic acid copolymer emulsion (EAA, melting point 85°C): 65 parts; microencapsulated blocked isocyanate (unsealing temperature 125°C): 10 parts; organobentonite (rheology control agent): 5 parts; dipropylene glycol butyl ether (film-forming aid): 3 parts; deionized water: 30 parts Example 4

[0050] The difference between Example 4 and Example 1 is that a three-color nano-pigment dispersion is used in step S3. Specifically, the nano-pigment dispersion has three colors: red, black, and blue, with a solid content of 40% and a pigment particle size D90 < 150 nm. In Example 1 of this application, the nano-pigment dispersion has three colors: red, black, and blue.

[0051] Specifically, step S3 includes the following steps: In area B of the release film, three-color printing is performed using a 200-mesh screen. Each color paste is prepared online by mixing water-based photosensitive binder and nano-pigment dispersion at a weight ratio of 8:2. Specifically, the first color (blue) is printed by immediately passing it through a curing channel, first drying it at 70℃ with mid-wave infrared light for 30 seconds, and then curing it with a 395nm UV LED lamp at an energy of 1000 mJ / cm². The second color (black) is printed and cured by overprinting a blue pattern on top of the first color, under the same curing conditions. The third color (red) is printed and cured by overprinting a green pattern on top of the second color, first drying it at 75℃ with mid-wave infrared light for 40 seconds, and then curing it with a 395nm+365nm dual-wavelength UV LED lamp at an energy of 1200 mJ / cm².

[0052] Comparative Example 1 Comparative Example 1 uses existing adhesive-free edge heat transfer technology. S1: Use a release film from the existing technology and apply a water-based polyurethane layer as a heat transfer layer on the film; coat the back of the heat transfer layer pattern with PU hot melt adhesive powder and attach it to the back of the heat transfer layer pattern. S2: Place the heat transfer layer coated with hot melt adhesive powder in a 90℃ constant temperature room for 12 hours to set.

[0053] S3: Place the heat transfer layer on the fabric and press it at 150℃ and 0.5MPa pressure for 60 seconds.

[0054] Comparative Example 2 The difference between Comparative Example 2 and Comparative Example 1 is that in step S4, an aqueous adhesive slurry was not used for coating. Steps S1, S2, and S3 are exactly the same as in Example 1 of this invention. In step S4, a single-component thermoplastic polyurethane (TPU) aqueous dispersion is used as the adhesive layer, without the addition of microencapsulation crosslinking agents and organobentonite. Finally, in step S5, the material is pressed at 150°C and 0.5 MPa pressure for 60 seconds (conventional process).

[0055] This application presents performance tests on Examples 1-4 and Comparative Examples 1-2. These tests specifically include measuring the adhesive edge width, testing tensile elasticity, water resistance, and VOC content.

[0056] Specifically, the glue edge width is measured using an optical microscope at the widest point of glue overflow at the edge of the pattern, in μm. Tensile elasticity is tested by stretching the fabric to 100% deformation and observing the pattern's condition, checking for cracking, micro-cracks, or whitening. Washability is tested according to the national standard GB / T 8628-2013, undergoing 25 cycles of testing. Additionally, VOCs content is tested according to the national standard GB / T 2912.1-2009 (g / kg). The test results are summarized in Table 1 below.

[0057] Table 1, Performance Test Tables of Examples 1-4 and Comparative Examples 1-2

[0058] Analysis of Comparative Example 1 and Example 1 shows that in the prior art, when solvent-based inks are heated to melt adhesive powder to process multi-color patterns, there are serious problems such as adhesive edges, cracking, hard feel and excessive VOCs, which cannot meet the requirements of high-quality multi-color transfer printing.

[0059] Another difference between Comparative Example 2 and Example 1 is that water-based adhesive paste was not used for coating in step S4. Although the color bleeding problem was solved, the control of adhesive edges and elastic properties were significantly reduced, which proves that the synergistic effect of microcapsule crosslinking agent and thixotropic agent is crucial to achieving "adhesive-free" and "high elasticity".

[0060] Furthermore, analysis of Examples 1, 2, and 3 shows that when the high-elasticity water-based underlayer slurry in step S2 and the water-based adhesive slurry in step S4 are within the specified range, their tensile properties, water resistance, and adhesive edge width can all achieve ideal results.

[0061] Furthermore, regarding the analysis of two-color and three-color printing, this application designated Example 1 as Group A and Example 4 as Group B, and conducted a water resistance analysis using GB / T 8628-2013, performing 25 cycles of testing. Example 1 and Comparative Example 4 did not exhibit severe discoloration, blistering, or peeling, demonstrating that this application can address interlayer interference, color overlay, and composite elasticity matching issues arising from multi-color printing. Multi-color transfer printing is not simply a matter of color overlay but a complex systemic problem requiring collaborative and innovative design of the substrate, ink, adhesive, and process.

[0062] It should be noted that the order of the embodiments described above is merely for descriptive purposes and does not represent the superiority or inferiority of the embodiments. Furthermore, specific embodiments have been described above. Other embodiments are within the scope of the appended claims. In some cases, the actions or steps described in the claims can be performed in a different order than those shown in the embodiments and still achieve the desired results. In some implementations, multitasking and parallel processing are also possible or may be advantageous.

[0063] The above description is only a preferred embodiment of this application and is not intended to limit this application. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

[0064] This specification is merely an illustrative description of this application and is intended to cover any and all modifications, variations, combinations, or equivalents within the scope of this application. Clearly, those skilled in the art can make various alterations and modifications to this application without departing from its scope. Therefore, if such modifications and modifications fall within the scope of this application and its equivalents, this application intends to include such modifications and modifications.

Claims

1. A multi-color glueless edge heat transfer printing technique, characterized by, The method comprises the following steps: S1: preparing a composite release film, the release surface comprises a bottom layer printing A area, a pattern printing B area and an adhesive layer bearing C area with gradually increasing release force; S2: applying water-based polyurethane-acrylic hybrid primer slurry on the A area, and sequentially performing hot air drying and ultraviolet light curing to form a high-elasticity primer layer; S3: using water-based slurry of at least two kinds of nano pigment dispersions for multi-color overprint on the B area, and immediately performing light curing after each color printing; S4: applying water-based adhesive slurry containing low-temperature response components and high-temperature response components on the pattern layer of the C area, and performing pre-baking; S5: superimposing the treated transfer film and the fabric to perform transfer printing, and tearing off the release film after cooling to obtain a multi-color glue-free edge transfer product.

2. The multi-color glueless edge heat transfer technology of claim 1, wherein, In the step S1, the low-energy ultraviolet curing silicone oil is coated on the PET base film in batches by gravure coating method, and the partition control is realized by differential ultraviolet curing energy; The coating amount of the A area is 0.8 g / m², the ultraviolet curing energy is 120 mJ / cm², and the release force of the A area is 0.03 N / 25mm; The ultraviolet curing energy of the second coating of the B area is 240 mJ / cm², and the release force of the B area is 0.08 N / 25mm; The ultraviolet curing energy of the third coating of the C area is 400 mJ / cm², and the release force of the C area is 0.35 N / 25mm.

3. The multi-color glueless edge heat transfer technology of claim 1, wherein, In the step S2, the water-based polyurethane-acrylic hybrid primer slurry comprises the following components by weight: Water-based polyurethane dispersion: 60-80 parts; Water-based self-crosslinking acrylic emulsion: 20-40 parts; Nanoscale colloidal silicon dioxide: 5-10 parts; Ultraviolet cationic photoinitiator: 1-2 parts.

4. The multi-color glueless edge heat transfer technology of claim 3, wherein, In the step S2, the hot air drying conditions are: temperature 75-85℃, time 80-100 seconds; The ultraviolet light curing conditions are: using a 254nm short-wave ultraviolet lamp, energy 120-180 mJ / cm².

5. The multi-color glueless edge heat transfer technology of claim 1, wherein, In the step S3, the water-based slurry is obtained by online mixing water-based photosensitive binder and nano pigment dispersion liquid at a weight ratio of (7-9):(1-3).

6. The multi-color glueless edge heat transfer technology of claim 5, wherein, The pigment particle size D90 of the nano pigment dispersion liquid is less than 150nm, and the solid content is 35-45%; the water-based photosensitive binder is a photosensitive water-based acrylic resin with double bonds grafted on the molecular chain, and contains 2-4% of a photoinitiator.

7. The multi-color glueless edge heat transfer technology of claim 5, wherein, In the step S3, the light curing operation conditions are: drying for 25-35 seconds at a medium-wave infrared temperature of 70-75℃, and curing at an energy of 800-1200 mJ / cm² by using a 395nm ultraviolet LED lamp; the curing energy of the last color is not less than 1000 mJ / cm².

8. The multi-color glueless edge heat transfer technology of claim 1, wherein, In the step S4, the water-based adhesive slurry comprises the following components by weight: Ethylene-acrylic acid copolymer emulsion (EAA): 55-65 parts; Microencapsulated blocked isocyanate: 6-10 parts; Organic bentonite: 3-5 parts; Film-forming aid: 1-3 parts.

9. The multi-color glueless edge heat transfer technology of claim 8, wherein, In the step S4, the pre-baking conditions are: temperature 85-95℃, time 8-12 minutes.

10. The multi-color glueless edge heat transfer printing technology of claim 9, wherein, In the step S5, the transfer film is superimposed with the fabric to perform the transfer pressing process parameters: Flow penetration stage: temperature 90-100℃, pressure 0.4-0.6 MPa, time 8-12 seconds; Crosslinking trigger stage: temperature 125-135℃, pressure 0.7-0.9 MPa, time 12-18 seconds; Shaping stable stage: temperature 125-135℃, pressure 0.1-0.3 MPa, time 5-10 seconds.

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