Gilding method and apparatus

Abstract

This invention discloses a hot stamping method and equipment, relating to the field of printing and processing technology. It includes the following steps: (1) using a printing device to partially apply water-based hot melt adhesive to the area to be hot stamped on the substrate to form a preset pattern; (2) drying the substrate after applying the water-based hot melt adhesive; and (3) using hot stamping paper without a hot melt adhesive layer to be synchronously transported with the substrate, and using a hot stamping roller to transfer the hot stamping paper to the surface of the substrate according to the hot melt adhesive pattern. Compared with the prior art, this invention, by using a printing device to partially apply hot melt adhesive to the area to be hot stamped on the substrate to form a preset pattern, eliminates the need to apply adhesive to the entire surface behind the aluminum plating layer of the hot stamping paper. It uses partial application of adhesive instead of full application, significantly reducing the amount of hot melt adhesive used and lowering material costs. It also uses a flat roller instead of a carved hot stamping roller for heating and pressing to achieve hot stamping. The cost of the flat roller is only one-tenth that of the carved roller, greatly reducing the investment in the carved plate.

Description

Technical Field

[0001] This invention relates to the field of printing and processing technology, and in particular to a hot stamping method and equipment that does not necessarily require the use of a hot stamping engraving plate for round pressing. Background Technology

[0002] Hot stamping, a decorative technique in the printing and packaging industry, works by using a heat transfer effect to transfer aluminum foil from hot stamping paper to the surface of the substrate, forming patterns or text with a metallic luster, thereby enhancing the product's visual appeal and market competitiveness. Current hot stamping processes typically use hot stamping paper composed of a base film, release layer, coloring layer, metallized layer, and hot melt adhesive layer. During operation, the substrate is fed to the hot stamping machine by a conveyor roller and overlaps with the hot stamping paper. After the hot stamping roller contacts the paper, pressure is applied to the substrate. The hot stamping roller then transfers the foil and its image onto the substrate, completing the hot stamping process.

[0003] The existing hot stamping process has the following drawbacks: 1. Hot stamping foil uses a full-surface hot melt adhesive layer, which requires a large amount of hot melt adhesive and results in high material costs; 2. Hot stamping rollers require engraving of graphics and text, resulting in high processing costs and significant investment.

[0004] Another hot stamping method is cold foil stamping. The principle is to apply cold foil to the substrate surface using digital printing or other methods, detailing a portion of the design. Then, a cold foil stamping roller, which does not require heating, presses the special cold foil stamping film to transfer the foil, completing the process. However, this type of cold foil stamping process primarily uses UV adhesives, which require high-wattage ultraviolet light for drying and cannot be completely dried; otherwise, the UV adhesive loses its adhesiveness and the aluminum plating layer cannot be transferred. This drying process is energy-intensive, produces light pollution and large amounts of ozone, is environmentally unfriendly, and cannot be used in many fields such as food and pharmaceuticals. Furthermore, UV adhesives are expensive, resulting in high costs. Summary of the Invention

[0005] This invention provides a hot stamping method and equipment that can solve the problems of high material costs and large investment in hot stamping plates in existing hot stamping processes.

[0006] To solve the above problems, the technical solution adopted by the present invention is: this hot stamping method includes the following steps: (1) Using printing equipment, water-based hot melt adhesive is applied locally to the area of ​​the substrate to be hot-stamped to form a preset pattern. (2) The substrate after the water-based hot melt adhesive has been applied is dried to dry the water-based hot melt adhesive; (3) Hot stamping foil without hot melt adhesive layer is synchronously transported with the substrate and hot stamping roller is used to transfer the hot stamping foil to the surface of the substrate according to the hot melt adhesive pattern.

[0007] In the above-mentioned hot stamping method, a more specific technical solution may be: the hot stamping paper is composed of a base film, a release layer, a coloring layer and an aluminum plating layer in sequence.

[0008] In some possible implementations, the hot stamping roller is a flat roller.

[0009] In some possible implementations, the drying temperature is 30°C to 120°C.

[0010] In some possible implementations, the hot pressing temperature is 60°C to 200°C, and the pressure is 0.1 MPa to 5 MPa.

[0011] The hot stamping equipment of the present invention includes a printing unit, a drying unit and a hot stamping unit arranged sequentially in the direction of substrate conveying; The printing unit is used to apply water-based hot melt adhesive to the area of ​​the substrate to be hot-stamped. The drying unit is used to heat and dry the printing substrate; The hot stamping unit includes a flat roller as a hot stamping roller, a hot stamping base roller, and a hot stamping paper conveying mechanism. The hot stamping paper used in conjunction with the hot stamping unit is composed of a base film, a release layer, a coloring layer, and an aluminum plating layer in sequence.

[0012] In some possible implementations, there are multiple printing units, and water-based hot melt adhesive is filled into the ink cartridge of the last printing unit according to the direction of travel of the substrate, so as to achieve local adhesive application by printing.

[0013] In some possible implementations, the drying unit is a hot air dryer or an infrared dryer.

[0014] In some possible implementations, the hot stamping unit further includes a hot stamping foil unwinding mechanism, a hot stamping foil base film winding mechanism, and two negative pressure suction chambers.

[0015] By adopting the above technical solution, the present invention has the following advantages compared with the prior art: 1. Since the water-based hot melt adhesive is applied locally to the area of ​​the substrate to be hot-stamped using printing equipment to form a preset pattern, it is not necessary to apply adhesive to the entire surface behind the aluminum plating layer of the hot-stamping foil. By using localized adhesive application instead of applying adhesive to the entire surface, the amount of hot melt adhesive used is greatly reduced, thus lowering material costs.

[0016] 2. This invention uses a printing plate instead of an engraved hot stamping plate, allowing a flat roller to replace the engraved hot stamping plate roller in the hot stamping unit. The flat roller is reusable, has extremely low cost, and greatly reduces the problems of large investment in engraved plates and long processing cycles.

[0017] 3. The matching hot stamping foil has no hot melt adhesive layer, making the hot stamping foil cost lower.

[0018] 4. The printing press is used for overprinting and positioning. The water-based hot melt adhesive is applied to the printing unit and the printed graphic for more precise overprinting and positioning, resulting in clear edges, good hot stamping consistency, and greatly improving the accuracy of hot stamping registration.

[0019] 5. The hot stamping roller is a smooth flat roller, which does not require custom engraving or plate changing, and is suitable for various batch and multi-variety production. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the structure of the present invention.

[0021] Figure 2 yes Figure 1 Enlarged view of point A.

[0022] Figure 3 This is a diagram of the layered structure of the hot stamping foil of this invention.

[0023] Figure 4 It's an image of household paper with a gold foil stamping effect.

[0024] Explanation of reference numerals in the attached figures: 1. Substrate; 2. Printing unit; 2-1. Ink cartridge; 3. Drying unit; 4. Hot stamping unit; 4-1. Hot stamping roller; 4-1-1. Heating plate; 4-2. Hot stamping base roller; 4-3. Hot stamping paper unwinding mechanism; 4-4. Hot stamping paper base film winding mechanism; 4-5. Negative pressure suction chamber; 5. Hot stamping paper; 5-1. Base film; 5-2. Release layer; 5-3. Coloring layer; 5-4. Aluminum coating layer; 6. Unwinder; 7. Paper roll winding machine; 8. First guide roller; 9. Second guide roller; 10. Third guide roller; 11. Fourth guide roller; 12. Tension detection roller; 13. Fifth guide roller; 14. Unwinding traction roller; 15. Glue roller; 16. Stepping roller. Detailed Implementation

[0025] To make the above-mentioned objects, features, and advantages of the present invention more readily understood, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Many specific details are set forth in the following description in order to provide a thorough understanding of the present invention; however, the present invention can be practiced in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0026] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "fixation," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0027] like Figures 1-3 The hot stamping equipment shown is designed to address the problems of high investment and material costs associated with existing hot stamping engraving plates. The equipment includes a printing unit 2, a drying unit 3, and a hot stamping unit 4 arranged sequentially along the transport direction of the substrate 1. The printing unit 2 applies water-based hot melt adhesive to the area of ​​the substrate 1 to be hot stamped. The drying unit heats and dries the substrate. The hot stamping unit 4 includes a flat roller as a hot stamping roller 4-1, a hot stamping base roller 4-2, and a hot stamping paper transport mechanism. The hot stamping paper 5 used in conjunction with the hot stamping unit 4 is composed of a base film 5-1, a release layer 5-2, a coloring layer 5-3, and an aluminum plating layer 5-4. In this embodiment, there are four sets of printing units 2. Water-based hot melt adhesive is filled in the ink cartridge 2-1 of the last set of printing units, arranged along the transport direction of the substrate 1, to achieve localized adhesive application through printing. Figure 4 As shown, in the first three printing units, peach blossom leaves and flowers are printed on the substrate using ink. When the substrate passes through the last printing unit, water-based hot melt adhesive is applied locally to form the pre-designed peach blossom branches. A hot air dryer is installed after the printing units. When the substrate printed with ink and water-based hot melt adhesive passes through the hot air dryer, the ink and water-based hot melt adhesive are dried. The hot stamping unit 4 also includes a hot stamping foil unwinding mechanism 4-3, a hot stamping foil base film winding mechanism 4-4, and two negative pressure suction cavities 4-5. The hot stamping foil unwinding mechanism 4-3 is used to unwind the hot stamping foil tape, and the hot stamping foil base film winding mechanism 4-4 is used to wind up the used hot stamping foil tape. The two negative pressure suction cavities 4-5 are respectively located on the left and right sides of the hot stamping station.

[0028] During operation, the substrate is unwound from the unwinding machine at position 6, passes through the ink-filled printing unit to print the preset pattern, and then passes through the water-based hot melt adhesive printing unit to apply the preset pattern. The substrate then passes through a dryer to dry the ink and water-based hot melt adhesive. Conveyed by the first guide roller 8, the second guide roller 9, and the third guide roller 10, the substrate passes through the hot stamping unit where the hot stamping roller 4-1 and the hot stamping base roller 4-2 are arranged vertically opposite to each other and run in opposite directions. On the other side… In the hot stamping unit 4, the hot stamping foil unwinding mechanism 4-3 unwinds the foil. The hot stamping foil 5, under the traction of the fourth guide roller 11, passes through the tension detection roller 12 to adjust the foil tension, then through the fifth guide roller 13, through the adjustment device composed of the unwinding traction roller 14 and the adhesive roller 15, and then through multiple guide rollers and the step roller 16 before simultaneously passing through the hot stamping roller with the substrate 1. The hot stamping roller rotates, and the heating plate 4-1-1 on the hot stamping roller heats and presses, causing the hot stamping foil to transfer the hot melt adhesive pattern onto the surface of the substrate, such as... Figure 4 As shown, the hot stamping foil is transferred into the branches of peach blossoms. Finally, the printed material is transported to the paper roll rewinding machine 7 for winding through multiple guide rollers. The remaining hot stamping foil is then sent to the hot stamping foil base film winding mechanism for winding through multiple guide rollers, step rollers, winding traction rollers, and tension detection rollers.

[0029] In cold foil stamping, the UV adhesive must maintain a certain level of tack after application, preventing complete drying and thus hindering contact between the substrate and the guide rollers. This invention, however, allows the substrate, after printing and adhesive application, to pass through multiple guide rollers without sticking after drying, before the foil stamping unit. In this invention, water-based hot melt adhesive is applied in the printing unit. After the printed pattern and the substrate coated with water-based hot melt adhesive pass through the drying unit, both the water-based hot melt adhesive pattern and the ink-printed pattern are dried together, causing the hot melt adhesive to lose its tack. If cold foil stamping is used at this point, the foil stamping rollers are not heated, and the aluminum plating layer of the foil will not transfer, preventing foil stamping from being completed. However, when the foil stamping paper and the substrate coated with water-based hot melt adhesive are heated and pressed together, the aluminum plating layer of the foil can be smoothly transferred to the substrate, thus completing the foil stamping process.

[0030] In other embodiments, the hot stamping unit can still be equipped with an engraving plate. When the hot stamping engraving plate is installed, the ink cartridge of the printing unit does not need to be filled with water-based hot melt adhesive, thus achieving traditional hot stamping. This hot stamping equipment can serve two purposes in one machine.

[0031] The embodiments described above merely illustrate several specific implementations of the present invention. Although the descriptions are quite specific and detailed, they should not be construed as limiting the scope of protection of this invention. It should be understood that those skilled in the art can make various modifications and improvements to this invention without departing from its core concept and basic principles. All such modifications and improvements should be considered within the scope of protection of this invention.

Claims

1. A hot stamping method, characterized in that... Includes the following steps: (1) Using printing equipment, water-based hot melt adhesive is applied locally to the area of ​​the substrate to be hot-stamped to form a preset pattern. (2) The substrate after the water-based hot melt adhesive has been applied is dried to dry the water-based hot melt adhesive; (3) Hot stamping foil without hot melt adhesive layer is synchronously transported with the substrate and hot stamping roller is used to transfer the hot stamping foil to the surface of the substrate according to the hot melt adhesive pattern.

2. The hot stamping method according to claim 1, characterized in that: The hot stamping foil is composed of a base film, a release layer, a coloring layer, and an aluminum plating layer in sequence.

3. The hot stamping method according to claim 1 or 2, characterized in that: The hot stamping roller is a flat roller.

4. The hot stamping method according to claim 1, characterized in that: The drying temperature is 30℃~120℃.

5. The hot stamping method according to claim 1, characterized in that: The hot pressing temperature is 60℃~200℃, and the pressure is 0.1Mpa~5Mpa.

6. A hot stamping equipment, characterized in that: It includes a printing unit, a drying unit, and a hot stamping unit arranged sequentially according to the direction of substrate transport; The printing unit is used to apply water-based hot melt adhesive to the area of ​​the substrate to be hot-stamped. The drying unit is used to heat and dry the printing substrate; The hot stamping unit includes a flat roller as a hot stamping roller, a hot stamping base roller, and a hot stamping paper conveying mechanism. The hot stamping paper used in conjunction with the hot stamping unit consists of a base film, a release layer, a coloring layer, and an aluminum plating layer in sequence.

7. The hot stamping equipment according to claim 6, characterized in that: The printing unit consists of multiple sets. According to the direction of travel of the substrate, the ink cartridge of the last set of printing units is filled with water-based hot melt adhesive to achieve localized adhesive application through printing.

8. The hot stamping equipment according to claim 6, characterized in that: The drying unit is a hot air dryer or an infrared dryer.

9. The hot stamping equipment according to claim 6, characterized in that: The hot stamping unit also includes a hot stamping foil unwinding mechanism, a hot stamping foil base film winding mechanism, and two negative pressure suction chambers.

Images