Printing process of anti-counterfeiting aluminized laser film

Abstract

The invention discloses a printing process of an anti-counterfeiting aluminized laser film, and belongs to the technical field of packaging material printing. The process comprises the following steps: performing plasma pretreatment on a bio-based degradable polyester film to enhance adhesive force, coating a temperature-sensitive color-changing layer to realize temperature response anti-counterfeiting, forming a diffraction grating structure through laser imprinting, performing gradient evaporation on an aluminum layer to construct an annular reflective difference band, and finally coating a degradable protective layer containing a plant extract. By optimizing process design and application of environment-friendly materials, the multi-layer anti-counterfeiting function and green production of the anti-counterfeiting film are achieved, the temperature-sensitive color-changing layer shows dynamic color change at different temperatures, and the complexity and reliability of anti-counterfeiting recognition are remarkably improved by combining annular reflection difference formed by the gradient aluminum layer; due to the use of the bio-based degradable material and the plant extraction protective layer, the product is endowed with a natural degradation characteristic, and the environmental burden is reduced; and cooling equipment is optimally used in the printing process, so that the uniformity and the structural stability of an aluminized layer are ensured.

Description

Technical Field

[0001] The present invention relates to the technical field of packaging material printing, and particularly to a printing process for an anti-counterfeiting aluminized laser film. Background Art

[0002] Laser anti-counterfeiting labels are often used in cigarette packaging boxes, wine packaging boxes and high-grade gift papers to improve the anti-counterfeiting level of their products. The traditional anti-counterfeiting film production process mostly relies on a single static anti-counterfeiting feature, such as fixed laser graphics or printed patterns, which are easy to be imitated and lack the ability of interactive verification.

[0003] At present, Chinese Patent Application No.: CN201710253405.X discloses a method for printing a laser holographic anti-counterfeiting label, including: printing a laser film, coating, laminating, drying and curing, and positioning printing; it also discloses a device for printing a laser holographic anti-counterfeiting label, including: a frame, a first unwind unit, a second unwind unit, a coating unit, a laminating unit, a drying and curing unit, and a printing unit.

[0004] However, in the prior art, the function of the anti-counterfeiting layer is relatively single, and it is not easy to achieve multi-dimensional anti-counterfeiting effects such as temperature response and optical gradient; the substrate mostly uses non-degradable petroleum-based films, and the production process involves solvent-based inks and high-energy-consuming processes, resulting in environmental pollution problems; in addition, the micro-cracks and uneven aluminum layer thickness caused by the accumulation of thermal stress in the aluminizing process affect the product yield and anti-counterfeiting effect. Summary of the Invention

[0005] The purpose of the present invention is to provide a printing process for an anti-counterfeiting aluminized laser film to solve the problems raised in the above background art.

[0006] In order to achieve the above purpose, the present invention adopts the following technical solutions: A printing process for an anti-counterfeiting aluminized laser film includes the following steps:

[0007] (a), Coating a temperature-sensitive color-changing layer on the surface of a bio-based biodegradable polyester film, which is formed by mixing cholesteric liquid crystal and acrylic resin in a ratio of 1:4-6 to form a dynamic anti-counterfeiting layer with color change in the temperature range of 30-50 °C;

[0008] (b), Completing laser embossing and pattern printing through a printing press to form a composite layer with both diffraction gratings and color graphics;

[0009] (c), After completing embossing and printing, using a cooling device for temperature reduction treatment to eliminate thermal stress and reduce the generation of micro-cracks;

[0010] (d), Evaporating a gradient aluminum layer on the surface of the cooled composite layer, with the thickness gradually changing from 25 nm in the central area to 45 nm in the edge area to form an annular reflective difference band;

[0011] (e) Coating a protective layer containing plant - derived antioxidants, which releases fluorescent markers during natural degradation.

[0012] Preferably, the surface of the bio - based degradable polyester film is pretreated by plasma with a treatment power of 50 - 100 W, a time of 30 - 60 seconds, and a surface tension of 38 - 42 mN / m.

[0013] Preferably, the gradient aluminum layer in step (d) is deposited by a magnetron sputtering coater, and the aluminum deposition gradient is controlled by moving a mask plate, with the aperture ratio of the mask plate linearly decreasing from 80% at the center to 30% at the edge.

[0014] Preferably, the protective layer in step (e) contains 5 - 8% by mass of sodium copper chlorophyllin, which exhibits red fluorescence under 365 nm ultraviolet light during degradation.

[0015] Preferably, after being processed by the cooling device in step (c), the temperature of the base film is reduced to below 40 °C to improve the linearity of the thickness gradient of the magnetron - sputtered aluminum layer.

[0016] Preferably, the cooling device includes a chassis, a bin cover is tightly fixed to the top side of the chassis, and bin lids are tightly connected to the four sides of the top of the bin cover. Inside the bin cover, a water - cooled roller, a nitrogen air - box mechanism, a first floating roller, and a second floating roller are arranged in sequence from left to right. The top of the nitrogen air - box mechanism penetrates through the inside of the bin lid. There are two groups of the first floating rollers located in the same vertical plane, and the first floating roller at the bottom side and the second floating roller are on the same horizontal plane. Air ports are opened on the outer surfaces of the first floating roller and the second floating roller, and the inside of the first floating roller and the second floating roller is connected to the external gas end to allow air flow to blow out through the air ports of the first floating roller and the second floating roller. The nitrogen air - box mechanism includes a frame base tightly fixed to the bin cover on both left and right sides, a nitrogen air - curtain main body embedded in the top side inside the frame base, an air outlet arranged in the upper middle part inside the frame base, an air inlet arranged in the lower part inside the frame base, and a spreading structure tightly fixed to the bottom side inside the frame base. The top side of the nitrogen air - curtain main body is embedded in the inside of the bin lid. The air inlet at the top side is communicated with the nitrogen air - curtain main body. Through - holes for the base film to pass through are opened on both left and right sides of the frame base.

[0017] Preferably, the stretching structure includes a vertical plate with its bottom side fastened to the frame base, a jacking assembly connected to the bottom side of the front part of the vertical plate, a first motor fastened to the left side of the top of the jacking assembly, a main transmission belt connected to the rear output end of the first motor, and a delaying assembly connected to the right rear side of the main transmission belt. The main transmission belt includes two transmission belt pulleys and a transmission belt. The transmission belt pulley on the left is connected to the rear output end of the first motor. The middle side of the rear part of the transmission belt pulley on the right is connected to the delaying assembly, and the middle side of the front part of the transmission belt pulley on the right is rotatably connected to the jacking assembly. The bottom side of the front part of the delaying assembly is fixed to the jacking assembly. An arc-shaped groove is formed in the upper right side inside the vertical plate, and the front part of the delaying assembly is disposed through the inside of the arc-shaped groove.

[0018] Preferably, the jacking assembly includes a pad frame with its rear bottom fastened to the vertical plate, a second motor locked and fixed to the upper right part of the top of the pad frame, a chute shaft rod connected to the left output end of the second motor, bearing blocks wrapped around the left and right sides of the chute shaft rod, a slider slidably connected to the top side of the chute shaft rod, a displacement block fixed to the top side of the slider, a push rod rotatably connected to the top side of the displacement block, and a carrier plate frame rotatably connected to the top end of the push rod. The left side of the carrier plate frame is rotatably connected to the pad frame. The left side of the top of the carrier plate frame is fastened to the first motor, and the right side of the top of the carrier plate frame is rotatably connected to the transmission belt pulley on the right. The bottom of the bearing block is fixed to the pad frame. Two communicating spiral grooves are formed on the outer surface of the chute shaft rod. Circular openings are formed on both the left and right sides of the displacement block, and the bottom of the displacement block is slidably connected to the pad frame horizontally. The chute shaft rod is disposed through the inside of the circular openings.

[0019] Preferably, the delaying assembly includes a bracket with its front side fixed to the jacking assembly, a rectangular frame integrally formed on the rear side of the bracket, a first remote rod disposed in the middle of the front part of the rectangular frame, a column rod fixed to the bottom side of the front part of the first remote rod, a first support roller rotatably connected to the top of the front side of the first remote rod, a first L-shaped rod rotatably penetrating through the middle and lower part of the front part of the first remote rod, a rotation seat rotatably connected to the bottom side of the rear part of the first L-shaped rod, a second L-shaped rod rotatably penetrating through the inside of the rear part of the rotation seat, a second rocker rotatably connected to the rear part of the second L-shaped rod, a second support roller rotatably disposed on the top of the rear side of the second rocker, and a support column rotatably connected to the bottom side of the front part of the second rocker. The front end of the column rod is connected to the middle part of the transmission belt pulley on the right. The middle side of the bottom of the rotation seat is rotatably connected to the rectangular frame. The support column is fixedly disposed through the middle side inside the rectangular frame, and the front part of the support column is rotatably connected to the first remote rod.

[0020] Preferably, the first remote rod and the second rocker have the same structure and size, and are symmetrically arranged left and right in the middle of the rectangular frame. The first support roller and the second support roller have the same structure and size, and are both elliptical structures with a high middle and low ends.

[0021] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0022] Through optimizing the process design and applying environmentally friendly materials, the present invention realizes the multi-level anti-counterfeiting function and green production of the anti-counterfeiting film. The temperature-sensitive color-changing layer presents dynamic color changes at different temperatures, combined with the annular reflection difference formed by the gradient aluminum layer, significantly enhancing the complexity and reliability of anti-counterfeiting identification; the use of bio-based degradable materials and plant extract protective layers endows the product with the characteristic of natural degradation, reducing the environmental burden; and the cooling equipment optimized in the printing process can effectively eliminate thermal stress, ensuring the uniformity and structural stability of the aluminized layer, providing technical guarantee for the production of high-quality anti-counterfeiting films.

[0023] The water-cooled roller of the cooling equipment of the present invention is internally provided with an ethylene glycol circulating liquid for rapid contact cooling with the base film, stably reducing the temperature of the back surface of the base film from 80°C to 50°C, and performing vertical purging of clean nitrogen through the nitrogen air box mechanism for synchronous cooling and removing residual ozone and dust on the surface of the base film. After nitrogen purging, it is suspended by the non-contact air cushions of the first suspension roller and the second suspension roller to further reduce the temperature of the base film, so as to improve the cooling efficiency of the base film.

[0024] The top side of the air inlet of the nitrogen air box mechanism of the present invention is connected to the nitrogen air curtain main body for recycling nitrogen. The nitrogen generated by the nitrogen air curtain main body is vertically purged onto the base film through the air inlet, playing the role of cooling and removing dust and ozone, and the base film can be lifted upward and guided to be flattened through the stretching structure, so as to increase the effective heat dissipation area of the base film and generate turbulence inside the frame seat to improve the heat exchange effect.

[0025] The present invention controls the forward and reverse rotation of the first motor to drive the column rod to drive the first rocker to perform left and right reciprocating swinging actions. When the first rocker swings left and right, the rotating seat rotates above the rectangular frame through the first L-shaped rod. Under the action of the rotating seat, the second L-shaped rod drives the second rocker to perform a swinging action in the opposite direction to the first rocker, so that the first support roller and the second support roller scrape and flatten the base film on the front and back sides below the base film, forming different arc curves on the front and back sides of the base film, so as to facilitate the flattening of the base film and make the gas blown onto the base film generate turbulence, improving the cooling effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a schematic block diagram of the printing process flow of the anti-counterfeiting aluminized laser film of the present invention;

[0027] Figure 2 It is a schematic structural diagram of the cooling equipment of the present invention;

[0028] Figure 3 It is a schematic structural diagram of the connection between the bin cover and the nitrogen air box mechanism of the present invention;

[0029] Figure 4Schematic diagram of the stretching structure of the present invention;

[0030] Figure 5 Schematic diagram of the jacking component of the present invention;

[0031] Figure 6 Schematic diagram of the delaying component of the present invention;

[0032] Figure 7 For the present invention Figure 6 Left view structure diagram;

[0033] Figure 8 Schematic diagram of the connection between the indexing seat and the rectangular frame of the present invention.

[0034] In the figure: chassis - 1, bin cover - 2, bin lid - 3, water - cooled roller - 4, nitrogen air box mechanism - 5, first floating roller - 6, second floating roller - 7, frame seat - 51, nitrogen air curtain main body - 52, air outlet - 53, air inlet - 54, stretching structure - 55, vertical plate - 551, jacking component - 552, first motor - 553, main drive belt - 554, delaying component - 555, arc groove - 5511, cushion rack - 5521, second motor - 5522, sliding groove shaft rod - 5523, bearing block - 5524, slider - 5525, shifting block - 5526, push rod - 5527, carrier plate rack - 5528, support - 5550, rectangular frame - 5551, column rod - 5552, first rocker - 5553, first support roller - 5554, first L - shaped rod - 5555, indexing seat - 5556, second L - shaped rod - 5557, second rocker - 5558, second support roller - 5559, support column - 55510. Detailed implementation manners

[0035] In order to further explain the technical solution of the present invention, it will be elaborated in detail through specific embodiments below.

[0036] Please refer to Figure 1 , the present invention provides a printing process for anti - counterfeiting aluminized laser film, including the following steps:

[0037] (a), The surface of the bio - based biodegradable polyester film is pretreated by plasma, with a treatment power of 80W and a time of 60 seconds, and the surface tension reaches 40 mN / m. Then, a thermosensitive color - changing layer is coated on the surface of the bio - based biodegradable polyester film. This layer is formed by mixing cholesteric liquid crystal and acrylic resin in a ratio of 1:4 - 6 to form a dynamic helical periodic structure, thereby forming a dynamic anti - counterfeiting layer with color change in the temperature range of 30 - 50 °C, which can achieve temperature - response anti - counterfeiting distinguishable by the naked eye;

[0038] (b), Complete laser imprinting and pattern printing through a printing machine to form a composite layer with both diffraction gratings and color graphics and texts;

[0039] (c), After stamping and printing, use a cooling device for temperature reduction treatment. After being processed by the cooling device, the temperature of the base film is reduced to below 40 °C to eliminate thermal stress and reduce the generation of microcracks, and improve the linearity of the thickness gradient of the magnetron sputtered aluminum layer;

[0040] (d), Evaporate a gradient aluminum layer on the surface of the cooled composite layer. The gradient aluminum layer is evaporated by a magnetron sputtering coating machine. The aluminum deposition gradient is controlled by moving the mask plate. The opening rate of the mask plate linearly decreases from 80% at the center to 30% at the edge, and the thickness gradually changes from 25 nm in the central area to 45 nm in the edge area, forming an annular reflective difference band to improve the reflectivity difference;

[0041] (e), Coating a protective layer containing plant extract antioxidants can delay the oxidation of the aluminum layer and extend its life. The protective layer contains 5-8% by mass of sodium copper chlorophyllin, which shows red fluorescence under 365 nm ultraviolet light during degradation. This layer releases fluorescent markers during natural degradation to achieve environmentally friendly and traceable anti-counterfeiting.

[0042] Please refer to Figures 1-8, the present invention provides a printing process for an anti-counterfeiting aluminized laser film. In the printing process, a cooling device is optimally used. The cooling device includes a chassis 1, a bin cover 2 is tightly fixed to the top side of the chassis 1, and bin covers 3 are tightly connected to the four sides of the top of the bin cover 2. Inside the bin cover 2, a water-cooled roller 4, a nitrogen air box mechanism 5, a first floating roller 6 and a second floating roller 7 are arranged in sequence from left to right. The top of the nitrogen air box mechanism 5 penetrates and is arranged inside the bin cover 3. There are two groups of the first floating rollers 6 and they are located in the same vertical plane, and the first floating roller 6 at the bottom side and the second floating roller 7 are on the same horizontal plane. Air ports are provided on the outer surfaces of the first floating roller 6 and the second floating roller 7, and the inside of the first floating roller 6 and the second floating roller 7 is connected to the external gas end, so as to make the air flow out through the air ports of the first floating roller 6 and the second floating roller 7. The water-cooled roller 4 is internally provided with ethylene glycol circulating liquid to perform contact-type rapid cooling with the base film, stably reducing the temperature of the back surface of the base film from 80 °C to 50 °C, and performing vertical purging of clean nitrogen through the nitrogen air box mechanism 5 to perform synchronous cooling and remove residual ozone and dust on the surface of the base film. After nitrogen purging, non-contact air cushion suspension is performed through the first floating roller 6 and the second floating roller 7 to further reduce the temperature of the base film; the nitrogen air box mechanism 5 includes a frame base 51 tightly fixed to the bin cover 2 on the left and right sides, a nitrogen air curtain main body 52 embedded in the top side inside the frame base 51, an air outlet 53 arranged in the upper middle part inside the frame base 51, an air inlet 54 arranged in the lower part inside the frame base 51, and a stretching structure 55 tightly fixed to the bottom side inside the frame base 51. The top side of the nitrogen air curtain main body 52 is embedded inside the bin cover 3, and the top side of the air inlet 54 is communicated with the nitrogen air curtain main body 52 to perform recycling of nitrogen. Through holes for the base film to pass through are provided on the left and right sides of the frame base 51. Nitrogen is vertically purged onto the base film through the air inlet 54 to play a role in cooling, dust removal and ozone removal, and the base film can be lifted up and guided to be flat through the stretching structure 55 to increase the effective heat dissipation area of the base film and generate turbulence inside the frame base 51 to improve the heat exchange effect.

[0043] Among them, the stretching structure 55 includes a vertical plate 551 with its bottom side fastened to the frame base 51, a lifting assembly 552 connected to the front bottom side of the vertical plate 551, a first motor 553 fastened to the top left side of the lifting assembly 552, a main drive belt 554 connected to the rear output end of the first motor 553, and a delaying assembly 555 connected to the rear right side of the main drive belt 554. The main drive belt 554 includes two belt pulleys and a drive belt. The belt pulley on the left is connected to the rear output end of the first motor 553, the middle side of the rear part of the belt pulley on the right is connected to the delaying assembly 555, and the middle side of the front part of the belt pulley on the right is rotatably connected to the lifting assembly 552. Under the action of the first motor 553, the two belt pulleys rotate synchronously. The front bottom side of the delaying assembly 555 is fixed to the lifting assembly 552. An arc-shaped groove 5511 is formed in the upper right side inside the vertical plate 551, and the front part of the delaying assembly 555 is arranged inside the arc-shaped groove 5511. Under the action of the lifting assembly 552, the delaying assembly 555 makes an up-and-down reciprocating arc-shaped trajectory movement inside the arc-shaped groove 5511, so that the delaying assembly 555 drives the base film to make an up-and-down reciprocating displacement movement, generating turbulence inside the frame base 51 and increasing the effective heat dissipation area of the base film, thereby improving the heat dissipation effect.

[0044] Among them, the lifting assembly 552 includes a pad frame 5521 with its rear bottom side fastened to the vertical plate 551, a second motor 5522 locked and fixed to the upper right part of the top side of the pad frame 5521, a chute shaft rod 5523 connected to the left output end of the second motor 5522, bearing blocks 5524 wrapped around the left and right sides of the chute shaft rod 5523, a slider 5525 slidably connected to the top side of the chute shaft rod 5523, a displacement block 5526 fixed to the top side of the slider 5525, a push rod 5527 rotatably connected to the top side of the displacement block 5526, and a carrier plate frame 5528 rotatably connected to the top end of the push rod 5527. The left side of the carrier plate frame 5528 is rotatably connected to the pad frame 5521. The top left side of the carrier plate frame 5528 is fastened to the first motor 553, and the top right side of the carrier plate frame 5528 is rotatably connected to the belt pulley on the right. The bottom of the bearing block 5524 is fixed to the pad frame 5521. Two communicating spiral grooves are formed on the outer surface of the chute shaft rod 5523. Using the second motor 5522 as the power source, through the cooperation of the chute shaft rod 5523 and the slider 5525, the displacement block 5526 makes a lateral reciprocating displacement movement, so that the push rod 5527 drives the carrier plate frame 5528 to make an up-and-down reciprocating arc-shaped trajectory movement with the top left side of the pad frame 5521 as the base point. Round openings are formed on both the left and right sides of the displacement block 5526, and the bottom of the displacement block 5526 is slidably connected to the pad frame 5521 horizontally. The chute shaft rod 5523 is arranged inside the round openings to ensure the stability of the lateral displacement of the displacement block 5526.

[0045] Among them, the delay component 555 includes a bracket 5550 with its front side fixed to the jacking component 552, and a rectangular frame 5551 integrally formed at the rear side of the bracket 5550, so that the rectangular frame 5551 performs a synchronous up-and-down reciprocating arc-shaped trajectory shifting action under the action of the jacking component 552. A first remote rod 5553 is arranged in the middle of the front part of the rectangular frame 5551, a column rod 5552 is fixed to the bottom side of the front part of the first remote rod 5553, a first support roller 5554 is rotatably connected to the top of the front side of the first remote rod 5553, a first L-shaped rod 5555 penetrates and rotates through the middle and lower part of the front part of the first remote rod 5553, a rotating seat 5556 is rotatably connected to the bottom side of the rear part of the first L-shaped rod 5555, a second L-shaped rod 5557 penetrates and rotates through the rear side inside the rotating seat 5556, a second rocker 5558 is rotatably connected to the rear part of the second L-shaped rod 5557, a second support roller 5559 is rotatably arranged at the top of the rear side of the second rocker 5558, and a support column 55510 is rotatably connected to the bottom side of the front part of the second rocker 5558. Taking the support column 55510 as a fulcrum facilitates the rotation action of the second rocker 5558. The front end of the column rod 5552 is connected to the middle part of the belt pulley on the right side, so that the column rod 5552 drives the first remote rod 5553 to rotate through the belt pulley on the right side. The middle part of the bottom of the rotating seat 5556 is rotatably connected to the rectangular frame 5551, the support column 55510 is fixedly penetrated in the middle of the inside of the rectangular frame 5551, and the front part of the support column 55510 is rotatably connected to the first remote rod 5553. The first remote rod 5553 rotates under the support of the support column 55510. The structures and sizes of the first remote rod 5553 and the second rocker 5558 are the same, and they are arranged symmetrically left and right in the middle of the rectangular frame 5551. The structures and sizes of the first support roller 5554 and the second support roller 5559 are the same, and they are both elliptical structures with a high middle and low ends. By controlling the positive and negative rotation of the first motor 553, the column rod 5552 drives the first remote rod 5553 to perform a left-and-right reciprocating swinging action. When the first remote rod 5553 swings left and right, the rotating seat 5556 rotates above the rectangular frame 5551 through the first L-shaped rod 5555. Under the action of the rotating seat 5556, the second L-shaped rod 5557 drives the second rocker 5558 to perform a swinging action in the opposite direction to the first remote rod 5553, so that the first support roller 5554 and the second support roller 5559 scrape and flatten the base film on the front and rear sides under the base film, forming different arc curves on the front and rear sides of the base film, so as to facilitate the flattening of the base film and cause the gas blown to the base film to generate turbulence, improving the cooling effect.

[0046] A printing process for an anti-counterfeiting aluminized laser film of the present invention, and the working principle of the cooling equipment used in the printing process is as follows:

[0047] First, after printing and laminating the biobased degradable polyester film, place the laminated side facing up, and pass the biobased degradable polyester film through and in contact with the upper side of the water-cooled roller 4, above the first support roller 5554 and the second support roller 5559, inside the two first floating rollers 6, and above the second floating roller 7 in sequence;

[0048] Second, the bottom side of the biobased degradable polyester film contacts the upper side of the water-cooled roller 4 with ethylene glycol circulating liquid inside, and performs contact-type rapid cooling with the biobased degradable polyester film as the base film, so that the back side of the base film stably drops from 80 °C to 50 °C;

[0049] Third, the base film enters the inside of the frame base 51. After the nitrogen air curtain main body 52 generates nitrogen, the nitrogen is vertically blown to the base film above the first support roller 5554 and the second support roller 5559 through the air inlet 54, which plays the role of cooling, dust removal, and ozone removal. During the process of blowing nitrogen, control the start of the second motor 5522 and make the first motor 553 reciprocate forward and backward. Under the action of the second motor 5522, the chute shaft rod 5523 rotates. Through the cooperation of the chute shaft rod 5523 and the slider 5525, the displacement block 5526 performs a horizontal reciprocating displacement action, so that the push rod 5527 drives the carrier plate frame 5528 to perform an up-and-down reciprocating arc-shaped trajectory movement with the top left side of the cushion frame 5521 as the base point, so that the first support roller 5554 and the second support roller 5559 perform an up-and-down reciprocating movement of the arc-shaped trajectory to drive the base film to reciprocate up and down. And under the reciprocating forward and backward rotation of the first motor 553, the column rod 5552 drives the first rocker 5553 to perform a left-and-right reciprocating swinging action. When the first rocker 5553 swings left and right, the rotating seat 5556 rotates above the rectangular frame 5551 through the first L-shaped rod 5555. Under the action of the rotating seat 5556, the second L-shaped rod 5557 drives the second rocker 5558 to perform a swinging action in the opposite direction to the first rocker 5553, so that the first support roller 5554 and the second support roller 5559 scrape and flatten the base film on the front and back sides below the base film, so that different arc curves are formed on the front and back sides of the base film, so as to flatten the base film and make the gas blown to the base film generate turbulence for cooling treatment;

[0050] Fourth, the base film after nitrogen blowing passes through the inside of the two first floating rollers 6 and above the second floating roller 7. Airflows are blown out from the air outlets of the first floating roller 6 and the second floating roller 7 to generate non-contact air cushion suspension, further reducing the temperature of the base film.

[0051] The above are only preferred examples of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or perform equivalent replacements for some of the technical features. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A printing process for an anti-counterfeiting aluminized laser film, characterized in that, It includes the following steps: (a) Coating a thermochromic layer on the surface of the bio-based biodegradable polyester film. This layer is formed by mixing cholesteric liquid crystal and acrylic resin in a ratio of 1:4 - 6, forming a dynamic anti-counterfeiting layer with color change within the temperature range of 30 - 50 °C; (b) Completing laser imprinting and pattern printing through a printing press to form a composite layer with both diffraction gratings and color graphics; (c) After completing imprinting and printing, using a cooling device for temperature reduction treatment to eliminate thermal stress and reduce the generation of microcracks; (d) Evaporating a gradient aluminum layer on the surface of the cooled composite layer, with the thickness gradually changing from 25 nm in the central area to 45 nm in the edge area, forming an annular reflective difference band; (e) Coating a protective layer containing plant-derived antioxidants, which releases fluorescent markers during natural degradation.

2. The printing process of an anti-counterfeiting aluminized laser film according to claim 1, characterized in that: The surface of the bio-based biodegradable polyester film is pretreated by plasma, with a treatment power of 50 - 100 W, a time of 30 - 60 seconds, and a surface tension of 38 - 42 mN / m.

3. The printing process of an anti-counterfeiting aluminized laser film according to claim 1, characterized in that: The gradient aluminum layer described in step (d) is evaporated using a magnetron sputtering coating machine, and the aluminum deposition gradient is controlled by moving a mask plate. The aperture ratio of the mask plate linearly decreases from 80% in the center to 30% at the edge.

4. The printing process of an anti-counterfeiting aluminized laser film according to claim 1, characterized in that: The protective layer described in step (e) contains 5 - 8% by mass of sodium copper chlorophyllin, which exhibits red fluorescence under 365 nm ultraviolet light during degradation.

5. The printing process of an anti-counterfeiting aluminized laser film according to claim 1, characterized in that: After the treatment by the cooling device in step (c), the temperature of the base film is reduced to below 40 °C, improving the linearity of the thickness gradient of the magnetron-sputtered aluminum layer.

6. The printing process of an anti-counterfeiting aluminized laser film according to claim 1, characterized in that: The cooling device includes a chassis (1), a bin cover (2) is tightly fixed to the top side of the chassis (1), and bin lids (3) are tightly connected to the four sides of the top of the bin cover (2). Inside the bin cover (2), a water-cooled roller (4), a nitrogen air box mechanism (5), a first floating roller (6), and a second floating roller (7) are sequentially arranged from left to right. The top of the nitrogen air box mechanism (5) penetrates and is arranged inside the bin lid (3). There are two groups of the first floating rollers (6) and they are located in the same vertical plane, and the first floating roller (6) at the bottom side and the second floating roller (7) are on the same horizontal plane. Air ports are opened on the outer surfaces of the first floating roller (6) and the second floating roller (7), and the inside of the first floating roller (6) and the second floating roller (7) is connected to the external gas end, used to blow out air through the air ports of the first floating roller (6) and the second floating roller (7); The nitrogen air box mechanism (5) includes a frame base (51) tightly fastened to the left and right sides of the bin cover (2), a nitrogen air curtain main body (52) embedded in the top side inside the frame base (51), an air outlet (53) arranged in the upper middle part inside the frame base (51), an air inlet (54) arranged in the lower part inside the frame base (51), and a stretching structure (55) tightly fastened to the bottom side inside the frame base (51). The top side of the nitrogen air curtain main body (52) is embedded inside the bin lid (3), the top side of the air inlet (54) is communicated with the nitrogen air curtain main body (52), and through holes for the base film to pass through are opened on the left and right sides of the frame base (51).

7. The printing process of an anti-counterfeiting aluminized laser film according to claim 6, characterized in that: The stretching structure (55) includes a vertical plate (551) with its bottom side fastened to the frame base (51), a jacking assembly (552) connected to the front bottom side of the vertical plate (551), a first motor (553) fastened to the top left side of the jacking assembly (552), a main drive belt body (554) connected to the rear output end of the first motor (553), and a delaying assembly (555) connected to the rear right side of the main drive belt body (554). The main drive belt body (554) includes two belt pulleys and a drive belt. The belt pulley on the left side is connected to the rear output end of the first motor (553), the middle side of the rear part of the belt pulley on the right side is connected to the delaying assembly (555), and the middle side of the front part of the belt pulley on the right side is rotatably connected to the jacking assembly (552). The front bottom side of the delaying assembly (555) is fixed to the jacking assembly (552). An arc-shaped groove (5511) is formed in the upper right side inside the vertical plate (551), and the front part of the delaying assembly (555) is disposed through the inside of the arc-shaped groove (5511).

8. The printing process of an anti-counterfeiting aluminized laser film according to claim 7, characterized in that: The jacking assembly (552) includes a cushion frame (5521) with its rear bottom side fastened to the vertical plate (551), a second motor (5522) locked and fixed to the upper right part of the top side of the cushion frame (5521), a chute shaft rod (5523) connected to the left output end of the second motor (5522), bearing blocks (5524) wrapped around the left and right sides of the chute shaft rod (5523), a slider (5525) slidably connected to the top side of the chute shaft rod (5523), a displacement block (5526) fixed to the top side of the slider (5525), a push rod (5527) rotatably connected to the top side of the displacement block (5526), and a carrier plate frame (5528) rotatably connected to the top end of the push rod (5527). The left side of the carrier plate frame (5528) is rotatably connected to the cushion frame (5521). The top left side of the carrier plate frame (5528) is fastened to the first motor (553), and the top right side of the carrier plate frame (5528) is rotatably connected to the belt pulley on the right side. The bottom of the bearing block (5524) is fixed to the cushion frame (5521). Two communicating spiral grooves are formed on the outer surface of the chute shaft rod (5523). Round openings are formed on both the left and right sides of the displacement block (5526), and the bottom of the displacement block (5526) is horizontally slidably connected to the cushion frame (5521). The chute shaft rod (5523) is disposed through the inside of the round openings.

9. The printing process of an anti-counterfeiting aluminized laser film according to claim 7, characterized in that: The delay component (555) includes a bracket (5550) with its front side fixed to the jacking component (552), a rectangular frame (5551) integrally formed at the rear side of the bracket (5550), a first rocker (5553) disposed at the middle side of the front part of the rectangular frame (5551), a column rod (5552) fixed to the bottom side of the front part of the first rocker (5553), a first support roller (5554) rotatably connected to the top of the front side of the first rocker (5553), a first L-shaped rod (5555) rotatably penetrating through the middle and lower part of the front part of the first rocker (5553), a rotation seat (5556) rotatably connected to the bottom side of the rear part of the first L-shaped rod (5555), a second L-shaped rod (5557) rotatably penetrating through the rear side inside the rotation seat (5556), a second rocker (5558) rotatably connected to the rear part of the second L-shaped rod (5557), a second support roller (5559) rotatably disposed at the top of the rear side of the second rocker (5558), and a support column (55510) rotatably connected to the bottom side of the front part of the second rocker (5558). The front end of the column rod (5552) is connected to the middle part of the belt pulley on the right side. The middle side of the bottom of the rotation seat (5556) is rotatably connected to the rectangular frame (5551). The support column (55510) is fixedly penetrated through the middle side inside the rectangular frame (5551), and the front part of the support column (55510) is rotatably connected to the first rocker (5553).

10. The printing process of an anti-counterfeiting aluminized laser film according to claim 9, characterized in that: The first rocker (5553) and the second rocker (5558) have the same structure and size, and are symmetrically arranged left and right at the middle of the rectangular frame (5551). The first support roller (5554) and the second support roller (5559) have the same structure and size, and are both oval structures with a high middle and low ends.

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