Digital printing method

Abstract

A digital printing method, comprising the following steps: arranging, positioning and fixing a printing stock on a working platform; spray printing transfer varnish on the printing stock and curing same; performing transfer printing on the printing stock; an inkjet system spraying pigment ink on the printing stock for printing; spraying varnish on the printing stock, and applying powder; and spraying varnish on the printing stock, and performing UV curing. By adopting the digital printing method for printing, the integration of multiple processes of digital printing, transfer printing and powder application is achieved, the working efficiency is improved, transfer printing, powder application and printing can be performed when the conditions are met, the color fastness or registration accuracy of a product, thereby ensuring product quality.

Description

A digital printing method

[0001] The present application claims priority to the Chinese patent application No. 202410694033.4, filed on May 31, 2024, and entitled "A digital printing method", the content of which is incorporated herein by reference in its entirety. TECHNICAL FIELD

[0002] The present application relates to the technical field of digital printing, in particular to a digital printing method. BACKGROUND

[0003] Digital printers are very common in daily life. The existing digital printing processes mainly include spraying, transferring and powdering. However, in the actual printing process, printing (spraying) and transferring (thermal transfer and gold stamping) and powdering processes are used separately on different machines, and the fusion of digital printing, transferring (thermal transfer or gold stamping) and powdering processes cannot be achieved. This not only wastes time and effort, but also affects work efficiency. Moreover, transferring (thermal transfer and gold stamping) or powdering is performed after a period of time after printing, which affects the color fastness, positioning and color matching accuracy of the product, and also affects the product quality. SUMMARY

[0004] To solve the above technical problems, the present application provides a digital printing method, which realizes the fusion of digital printing, transferring and powdering processes, improves work efficiency and ensures product quality.

[0005] The technical solution adopted by the present application to solve the technical problems is as follows:

[0006] A digital printing method, comprising the following steps:

[0007] Positioning and fixing the printing material on the working platform;

[0008] Spraying and curing the transfer printing varnish on the printing material;

[0009] Transferring the printing material;

[0010] Spraying the pigment ink on the printing material by the inkjet system to print;

[0011] Spraying the varnish on the printing material and powdering;

[0012] Spraying the varnish on the printing material and UV curing.

[0013] Preferably, when the transfer printing varnish is sprayed on the printing material, the transfer printing varnish is sprayed on the place where transfer printing is needed, and the non-transfer printing varnish is sprayed on the place where transfer printing is not needed.

[0014] Preferably, the transfer printing is thermal transfer, the transfer printing film is heated by the transfer printing cylinder, and is pressed on the printing material.

[0015] The heating temperature of the transfer film is 80-200℃, the speed is 0.1-10 meters per minute, and the transfer pressure is 1.8-2.2t.

[0016] Preferably, the transfer is gold stamping, wherein the temperature of the electroplated aluminum foil is 130°-160°, the gold stamping pressure is 5t or more, and the gold stamping speed is 0.5-0.7 meters per minute.

[0017] Preferably, the four sides of the transfer film need to be tensioned during the transfer process of the printing material.

[0018] Preferably, in the process of powdering, the excess powder needs to be sucked away.

[0019] Preferably, the powdering is carried out by a powdering mechanism, which is arranged on the jet printing trolley, and the inside of the jet printing trolley is provided with a jet printing mechanism for printing.

[0020] Preferably, the powdering mechanism is arranged on both sides of the jet printing trolley, and each side is provided with a plurality of powdering mechanisms, and the plurality of powdering mechanisms are distributed in a rectangular array.

[0021] Preferably, the plurality of powdering mechanisms are used to spray different glittering powders.

[0022] Or part of the powdering mechanisms are used to spray different glittering powders, and the other part of the powdering mechanisms are used to spray the same glittering powder.

[0023] A digital printing method, comprising the following steps:

[0024] The printing material is positioned and fixed on the working platform;

[0025] The transfer varnish is jet printed on the printing material and cured;

[0026] The printing material is transferred;

[0027] The varnish is sprayed on the printing material, and powdering is carried out;

[0028] The varnish is sprayed on the printing material and cured, and the inkjet system sprays pigment ink on the printing material for printing;

[0029] The varnish is sprayed on the printing material, and UV curing is carried out.

[0030] The digital printing method has the advantages that the digital printing, transfer printing and powder spraying processes are integrated, the work efficiency is improved, and the transfer printing, powder spraying and printing can be performed after meeting the conditions, so that the coloring fastness and positioning color matching accuracy of the product are not affected, and the quality of the product is ensured. BRIEF DESCRIPTION OF DRAWINGS

[0031] Fig. 1 is a flow chart of the digital printing method according to the first embodiment of the present application.

[0032] Fig. 2 is a powder spraying principle diagram.

[0033] Fig. 3 is a flow chart of the digital printing method according to the second embodiment of the present application.

[0034] Wherein: 1 - mounting plate, 2 - unwinding roller, 21 - connecting part, 22 - supporting part, 3 - rack, 4 - gear, 5 - bearing seat, 6 - fixing ring, 7 - driving plate, 71 - driving hole, 8 - first mounting seat, 9 - push-pull shaft, a - second mounting seat, b - lifting cylinder, c - push-pull cylinder. DETAILED DESCRIPTION

[0035] The specific embodiments of the present application will be further described in detail below with reference to the accompanying drawings and embodiments. The following embodiments are used to illustrate the present application, but are not used to limit the scope of the present application.

[0036] In the present application, unless otherwise explicitly specified and limited, the terms "mounting", "connecting", "connecting", "fixing" and the like should be understood in a broad sense, for example, it can be fixedly connected, or it can be detachably connected, or it can be integrated; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium; it can be the internal communication of two elements or the interaction relationship between two elements. For those skilled in the art, the specific meaning of the above-mentioned terms in the present application can be understood according to the specific circumstances.

[0037] As shown in Fig. 1, the digital printing method according to the preferred embodiment of the present application comprises the following steps:

[0038] S1, the printing material is positioned and fixed on the working platform. Wherein, the working platform is provided with a positioning pin, and a printing mold corresponding to the positioning pin is provided. During printing, the printing material is sleeved on the printing mold to avoid deformation and displacement of the printing material during printing, thereby ensuring the printing quality.

[0039] S2, printing and curing the transfer printing varnish (UV resin, transfer printing glue, gold printing varnish) on the printing material by the inkjet nozzle. Specifically, the transfer printing varnish is printed on the place where the transfer printing is needed, and the blocking varnish is printed on the place where the transfer printing is not needed. The printing mode adopts the scanning inkjet printing or the multi-PASS printing.

[0040] S3, transferring the printing material;

[0041] In order to realize the digital printing and transfer printing perfect effect of the whole page multiple curved surface and high-low difference large complex shape product, the four sides of the transfer film need to be pneumatically tightened during the transfer printing, and the four side tension of the transfer film is accurately controlled through the air pressure, so that the problem of the digital printing and transfer film wrinkling of the whole page multiple curved surface and high-low difference large complex shape product is finally solved (the existing transfer printing and gold printing machine is single direction tightening).

[0042] In the application, the transfer printing is divided into two kinds, namely the heat transfer printing and the gold printing. The heat transfer printing process transfers the layer on the transfer film to the surface of the printing material through heating and pressing, which is lifelike and beautiful, and greatly improves the grade of the product. The gold printing process is to transfer the aluminum layer in the aluminum foil to the surface of the printing material to form a special metal effect by using the principle of hot pressing transfer. Specifically:

[0043] When the transfer printing is the heat transfer printing, the transfer film is heated by the transfer printing cylinder and is pressed on the printing material;

[0044] The heating temperature of the transfer film is 80-200 DEG C, such as 90 DEG C, 100 DEG C, 120 DEG C, 160 DEG C, 180 DEG C and the like; the transfer printing speed is 0.1-10 meters per minute, such as 0.2 meters, 0.6 meters, 1 meter, 2 meters, 3 meters, 5 meters, 8 meters and the like; the transfer printing pressure is 1.8-2.2 t, such as 1.9 t, 2 t, 2.1 t and the like. The specific parameters can be selected according to the actual situation, but through the experiment, the temperature, the speed and the pressure parameters are obtained, and when any one or two of them is not in the above range, the good transfer printing effect cannot be achieved. For example, when the temperature or the pressure does not reach the above range, the layer on the transfer film cannot be completely transferred to the printing material, and when the temperature or the pressure exceeds the above range, the transfer film and the printing material are adhered, which affects the product quality. If the speed exceeds the above range, the layer on the transfer film cannot be completely transferred to the printing material, and if the speed is lower than the above range, the transfer printing humidity is affected.

[0045] Therefore, when selecting, the temperature, the speed and the pressure should meet the above range at the same time, so as to ensure the best transfer printing effect.

[0046] When the transfer is gilding, the temperature of the aluminum foil is 130°-160°, the gilding pressure is 5t or more, and the gilding speed is 0.5-0.7 meters per minute. In actual production, the temperature, speed and pressure should all meet the above ranges to ensure the best gilding effect.

[0047] S4, the inkjet system sprays pigment ink onto the printing material for printing. The spraying is performed by a spraying trolley, and the spraying trolley is internally provided with a spraying mechanism for printing. During spraying, the required graphics are input into the computer, and after editing and processing by the electronic color separation system, the computer controls the inkjet system to directly spray gloss or pigment ink onto the fabric for printing. Inkjet printing can be divided into continuous inkjet and drop-on-demand inkjet according to the inkjet principle.

[0048] 1. Continuous inkjet

[0049] The principle of continuous inkjet is to make the ink spray out of the nozzle in the form of uniform and continuous droplets by applying high-frequency oscillation pressure to the ink. An electric field that changes synchronously with the graphic photoelectric conversion signal is provided at the nozzle. The sprayed droplets are selectively charged in the charging electric field, and when the droplet stream continues to pass through the deflection electric field, the charged droplets are deflected under the action of the electric field, and the uncharged droplets continue to maintain a straight flight state. The straightly flying droplets cannot reach the printing material and are recycled by the liquid collector. The charged droplets are sprayed onto the printing material to complete the printing.

[0050] 2. Drop-on-demand inkjet

[0051] The working principle of the drop-on-demand inkjet system is that when printing is required, the system applies high-frequency mechanical force and electromagnetic heat shock to the ink in the nozzle to form small droplets that are sprayed out of the nozzle to the set pattern under the control of the computer. The widely used drop-on-demand inkjet technology is thermal inkjet technology, which relies on heat pulsation to generate ink droplets. The computer controls a heating resistance wire to a specified temperature, causing the ink gas (mist) to be atomized and then sprayed out of the nozzle. Another technology is the voltage type inkjet system, which is controlled by the computer to impose an electric potential on the conductive material, causing the conductive material to compress in the direction of the electric field and expand in the vertical direction, thereby causing the ink to be sprayed.

[0052] Digital printing sprays color ink and gloss (UV resin, transfer glue, gilding gloss) onto the printing material through the nozzle

[0053] S5, gloss is sprayed on the printing material, and powder is scattered;

[0054] The dusting process is to sprinkle the gold powder, glitter powder, fluorescent powder, color powder, diamond powder, chameleon powder, UV color-changing powder, temperature color-changing powder, magnetic cat eye powder and other optical powder and special functional powder granular materials on the surface or middle layer of the printed product inkjet light oil (UV resin, transfer glue, gold stamping light oil) and solidify the process. That is, after the inkjet is completed, first sprinkle the light oil on the printing material and solidify, and then sprinkle the powder.

[0055] The dusting is carried out by a dusting mechanism arranged on the inkjet trolley. The inside of the inkjet trolley is provided with an inkjet mechanism for printing. The dusting mechanism is arranged on both sides of the inkjet trolley. Each side of the dusting mechanism is provided with a plurality of dusting mechanisms, and the plurality of dusting mechanisms are distributed in a rectangular array. The digital printing method of claim 8, wherein the plurality of dusting mechanisms are used to spray different flash powders; or part of the dusting mechanisms are used to spray different flash powders, and the other part of the dusting mechanisms are used to spray the same flash powder.

[0056] As shown in FIG. 2, therefore, in combination with the movement of the inkjet trolley driving the dusting mechanism and the arrangement mode of the dusting mechanism itself, the dusting mechanism can realize very beautiful three-dimensional space effect on the printing material. The realization mode is to present the visual effect of thousands of changes by multiple inkjet light oil and different dusting modes. We take four dusting mechanisms arranged on one side of the inkjet trolley as an example to illustrate:

[0057] The implementation process is as follows: first, the spray head trolley sprays a layer of varnish on the printing material (according to the required thickness), and then the powder scattering mechanism scatters the flash powder. The powder scattering mechanism can be in various combinations, and each time is different. The four powder scattering mechanisms on one side of the spray printing trolley can realize four times of scanning printing, and each time is different. Any combination mode can be realized. Two or more kinds of powder can be realized in one scanning printing, for example, the multiple rows of powder scattering in FIG. 2, such as ① and ②, ① and ④, ② and ③, and ③ and ④, which can realize the effect of the upper and lower rows on the product. The multi-level three-dimensional effect can also be realized, for example, the first pass of scanning printing is varnish (UV resin, transfer glue, gold varnish), and a bottom layer of powder (various combinations of powder scattering) is scattered. Then, the amount of ink sprayed by the varnish spray head is increased to cover a thicker layer of varnish on the first layer, and then the powder is scattered. This multi-level powder scattering can be two or three layers, and the layering can realize a powder scattering process with a three-dimensional effect. In the varnish spraying area, the area sprayed by the spray head is relatively wide, and the powder scattering area is relatively narrow compared to the varnish spraying area. When the trolley moves from left to right, the first area is sprayed, and the powder scattering mechanism is located to the left of the varnish spraying area. When the trolley moves to the rightmost position, the first area is completed and is cured by the UV lamp. Then, the marble beam moves a certain distance along the Y-axis, and then the trolley moves from left to right to spray varnish. The second area of varnish sprayed will cover the powder scattering area of the first area, and the process is repeated to achieve a special combination of various powders, which can be layered to present a three-dimensional space effect. The powder exists in the space and presents a beautiful effect. The powder scattering mechanism 43 can alternate or simultaneously scatter powder, so that the surface of the printing material can achieve more diversified and beautiful effects.

[0058] In addition, during the powder scattering process, the excess powder dust needs to be removed. The excess powder dust is removed by the air suction device to prevent the spray printing assembly from being blocked and to prevent air pollution and achieve environmental protection.

[0059] S6, spraying varnish on the printing material and performing UV curing.

[0060] Example Two

[0061] As shown in FIG. 3, the difference between the present embodiment and example one is the order of spraying and powder scattering, and the rest is the same. The specific brush printing method is as follows:

[0062] A digital printing method, comprising the following steps:

[0063] Positioning and fixing the printing material on the working platform;

[0064] Spraying transfer varnish on the printing material and curing;

[0065] Transferring the printing material;

[0066] Spraying the light oil on the printing material and performing powdering;

[0067] Spraying the light oil on the printing material and curing, and the inkjet system sprays the pigment ink on the printing material to perform printing;

[0068] Spraying the light oil on the printing material and performing UV curing.

[0069] By printing through the digital printing method of the present application, the fusion of digital printing, transfer printing and powdering is realized, the work efficiency is improved, and the transfer printing, powdering and printing can be performed after meeting the conditions, without affecting the color fastness and positioning color matching accuracy of the product, thereby ensuring the quality of the product.

[0070] In summary, by printing through the method of the present application, both printing and powdering can be realized, the powdering range and powdering amount are controllable, and the excess dust is removed by the air suction device to prevent the contamination of the printing assembly and block the nozzle, to prevent air pollution and achieve environmental protection; through the cooperation of transfer printing (thermal transfer printing, hot stamping), powdering, the pattern can achieve more realistic and more visual effects, so that designers can use more design elements to design products, and achieve the color restoration of the pattern to the real object, and increase the plating, laser, photoetching texture effect, some special metal colors such as gold and silver, and various process effects of any pigment and powder carried by the transfer film and other transfer materials, as well as gold and green powder, diamond powder, chameleon powder, fluorescent powder, ultraviolet color-changing powder, temperature color-changing powder, reflective powder, night light powder, magnetic cat eye powder and various optical and special functional powders, finally through the multifunctional digital printing machine of the present application, the digital inkjet printing effect with thousands of changes is realized, and the printing position is accurate, the effect is unique, and the operation is simple. Without any of the above processes, the technical effects cannot be achieved, and the fusion of the three processes cannot be achieved.

[0071] The above only describes the preferred embodiments of the present application, and it should be noted that for those skilled in the art, without departing from the technical principles of the present application, a number of improvements and replacements can be made, and these improvements and replacements should be considered as the protection scope of the present application.

Claims

1. A method of digital printing, characterized by: Includes the following steps: Position and fix the printing substrate on the work platform; The transfer varnish is sprayed onto the substrate and then cured. Transferring the print to the substrate; Inkjet systems spray pigment inks onto a substrate for printing. Spray varnish onto the printing substrate and sprinkle powder on it; Spray varnish onto the substrate and then UV cure it.

2. The method of digital printing according to claim 1, wherein: When the transfer varnish is sprayed onto the substrate, the transfer varnish is sprayed on the areas that need to be transferred, and the heat-resistant varnish is sprayed on the areas that do not need to be transferred.

3. The method of digital printing according to claim 1, wherein: The transfer is a heat transfer, in which the transfer film is heated by a transfer roller and pressed onto the substrate; The heating temperature of the transfer film is 80-200℃, the speed is 0.1-10 meters per minute, and the transfer pressure is 1.8-2.2t.

4. The method of digital printing according to claim 1, wherein: The transfer is hot stamping, wherein the temperature of the electroplated aluminum foil is 130° to 160°, the hot stamping pressure is above 5t, and the hot stamping speed is 0.5 to 0.7 meters per minute.

5. The method of digital printing according to claim 1, wherein: During the transfer process, the transfer film needs to be stretched taut on all four sides.

6. The method of digital printing according to any one of claims 1 to 5, wherein: During the powdering process, excess dust needs to be removed.

7. The method of digital printing according to any one of claims 1 to 5, wherein: The powder application is performed by a powder application mechanism, which is mounted on a printing carriage. The printing carriage is equipped with a printing mechanism for printing.

8. The method of digital printing according to claim 7, wherein: The powder-spraying mechanism is located on both sides of the printing carriage, with multiple powder-spraying mechanisms on each side, and the multiple powder-spraying mechanisms are distributed in a rectangular array.

9. The method of digital printing according to claim 8, wherein: Each of the aforementioned powder-spraying mechanisms is used to spray different glitter powders; One part of the powder-spraying mechanism is used to spray different glitter powders, while another part of the powder-spraying mechanism is used to spray the same glitter powder.

10. A method of digital printing, characterized by: Includes the following steps: Position and fix the printing substrate on the work platform; The transfer varnish is sprayed onto the substrate and then cured. Transferring the print to the substrate; Spray varnish onto the printing substrate and sprinkle powder on it; A varnish is sprayed onto the substrate and cured, and then the inkjet system sprays pigment inks onto the substrate for printing. Spray varnish onto the substrate and then UV cure it.

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