Aluminum-free packaging substrate for making a packaging bag and method for making the same, aluminum-free packaging article

Abstract

This application relates to the field of packaging manufacturing technology, and in particular to an aluminum-free packaging substrate for making packaging bags, a method for manufacturing the same, and aluminum-free packaging articles. The aluminum-free packaging substrate includes a packaging base material and an aluminum-free reflective layer. The aluminum-free reflective layer is disposed on at least a portion of one side surface of the packaging base material along a first direction, where the first direction is the thickness direction of the packaging base material. At least a portion of the side surface of the aluminum-free reflective layer facing away from the packaging base material has a three-dimensional structure, which is used to change the light propagation path. Because of this three-dimensional structure, when light shines on the surface of the aluminum-free reflective layer, the three-dimensional structure refracts and scatters the light at multiple angles, continuously changing the light propagation path. When the viewing angle changes, the incident angle of the light changes synchronously, and the light propagation path dynamically switches, forming a dazzling dynamic light and shadow effect. This makes the aluminum-free packaging substrate rich in color and has a dynamic visual effect, thus matching the differentiated design requirements of products.

Description

Technical Field

[0001] This application relates to the field of packaging manufacturing technology, and in particular to an aluminum-free packaging substrate for making packaging bags, a method for making the substrate, and aluminum-free packaging products. Background Technology

[0002] Current paper bags are limited to a single color, have a monotonous visual hierarchy, lack dynamic visual effects, and are difficult to match the design needs of product differentiation.

[0003] The information disclosed in this background section is intended only to enhance the understanding of the overall background of the invention and should not be construed as an admission or in any way implying that the information constitutes prior art known to those skilled in the art. Summary of the Invention

[0004] Therefore, it is necessary to address the problems of current paper bags having limited color options, monotonous visual layers, lack of dynamic visual effects, and difficulty in matching the design requirements of product differentiation by providing an aluminum-free packaging substrate for making packaging bags, its manufacturing method, and aluminum-free packaging products.

[0005] In a first aspect, this application provides an aluminum-free packaging substrate for making packaging bags, comprising:

[0006] Packaging base material;

[0007] An aluminum-free reflective layer is disposed on at least a portion of one side surface of the packaging substrate along a first direction, wherein the first direction is the thickness direction of the packaging substrate. At least a portion of the side surface of the aluminum-free reflective layer opposite to the packaging substrate has a three-dimensional structure, which is used to change the light propagation path.

[0008] In one embodiment, the three-dimensional structure includes a plurality of protrusions and a plurality of recesses, each of the protrusions and each of the recesses being adjacent to each other along a second direction, the second direction intersecting the first direction.

[0009] In one embodiment, along the first direction, the distance between the top end of the protrusion and the bottom end of the recess connected adjacently is h, satisfying: 0.3μm≤h≤1.2μm;

[0010] And / or, the surface of the protrusion is curved;

[0011] And / or, the surface of the recess is curved;

[0012] And / or, the cross-sectional area of ​​the protrusion in the second direction gradually increases from the top of the protrusion to its bottom.

[0013] And / or, the cross-sectional area of ​​the recessed portion in the second direction gradually increases from the top of the recessed portion to its bottom.

[0014] In one embodiment, the thickness of the packaging substrate along the first direction is H1, satisfying: 0.05mm≤H1≤0.5mm;

[0015] And / or, the thickness of the aluminum-free reflective layer along the first direction is H2, satisfying: 3μm≤H2≤10μm.

[0016] In one embodiment, the aluminum-free packaging substrate further includes a base coating layer, which is at least partially disposed between the packaging substrate and the aluminum-free reflective layer along the first direction.

[0017] In one embodiment, the thickness of the base coating along the first direction is H3, satisfying: 3μm≤H3≤5μm.

[0018] Secondly, this application also provides an aluminum-free packaging article, at least a portion of which includes the aluminum-free packaging substrate as described in the first aspect.

[0019] In one embodiment, the aluminum-free packaging product is a packaging bag, the packaging bag having a storage cavity and an opening communicating with the storage cavity, and the aluminum-free packaging substrate enclosing the storage cavity and the opening;

[0020] The aluminum-free packaging substrate includes a packaging base material and an aluminum-free reflective layer. At least a portion of the surface of the packaging base material facing away from the storage cavity is provided with the aluminum-free reflective layer, and at least a portion of the surface of the aluminum-free reflective layer facing away from the packaging base material is provided with a three-dimensional structure.

[0021] In one embodiment, the aluminum-free reflective layer is provided on the entire surface of the packaging substrate facing away from the storage cavity, and the three-dimensional structure is provided on the entire surface of the aluminum-free reflective layer facing away from the packaging substrate.

[0022] In one embodiment, a portion of the surface of the packaging substrate facing away from the storage cavity is provided with the aluminum-free reflective layer, and a portion of the surface of the aluminum-free reflective layer facing away from the packaging substrate is provided with the three-dimensional structure.

[0023] Thirdly, this application also provides a method for manufacturing an aluminum-free packaging substrate, comprising:

[0024] Coating: Applying a UV-cured aluminum-free coating to the packaging substrate;

[0025] Drying: The packaging substrate coated with the light-cured aluminum-free coating is dried so that the viscosity of the dried packaging substrate is 0.8N to 1.2N;

[0026] Hot pressing and photocuring: The three-dimensional texture of the photolithography film is hot-pressed onto the side surface of the packaging substrate coated with the photocurable aluminum-free coating after heat treatment, and photocuring is performed simultaneously;

[0027] Peeling: Peeling off the photolithography film and the packaging substrate.

[0028] In one embodiment, the drying temperature is 75°C to 85°C, and / or the drying time is 30s to 40s, and / or the drying air velocity is 3m / s to 5m / s.

[0029] In one embodiment, the photocuring includes a first stage, a second stage, and a third stage performed sequentially, wherein the photocuring wavelengths of the first stage, the second stage, and the third stage increase progressively, and the energy density of the second stage is greater than that of the first stage and the third stage, respectively.

[0030] In one embodiment, the hot pressing temperature is 60°C to 70°C, and / or the hot pressing pressure is 0.4MPa to 0.6MPa, and / or the hot pressing speed is 35m / min to 45m / min;

[0031] And / or, the photocuring wavelength of the first segment is 362nm~368nm, the energy density is 800mJ / cm²~1200mJ / cm², the photocuring line power is 80W / cm~100W / cm, and the light intensity density is 600W / cm². 2 ~800W / cm 2 The curing time is 1.0s to 1.5s, and the temperature in the light zone is 50℃ to 55℃.

[0032] And / or, the second segment has a photocuring wavelength of 382nm to 388nm, an energy density of 1800mJ / cm² to 2500mJ / cm², a photocuring line power of 120W / cm² to 150W / cm², and a light intensity density of 1000W / cm². 2 ~1200W / cm 2 The curing time is 1.5s to 2.0s, and the temperature in the light zone is 55℃ to 60℃.

[0033] And / or, the photocuring wavelength of the third segment is 392nm~398nm, the energy density is 1500mJ / cm²~2200mJ / cm², the photocuring line power is 100W / cm~120W / cm, and the light intensity density is 800W / cm². 2 ~1000W / cm 2The curing time is 1.5s to 2.5s, and the temperature of the light zone is less than or equal to 45℃.

[0034] In one embodiment, the material of the packaging substrate includes a paper base;

[0035] And / or, the material of the photocurable aluminum-free coating includes 38%–42% modified epoxy acrylic resin, 25%–28% polyurethane acrylic resin, 15%–18% monofunctional reactive diluent, 8%–10% difunctional reactive diluent, 3%–4% ultraviolet photoinitiator, 1.5%–2.5% nano-silica light-diffusing agent, 0.3%–0.5% leveling agent, and 0.2%–0.5% defoamer;

[0036] And / or, the photocurable aluminum-free coating is applied using a screen roller with a screen roller count of 100 LPI to 300 LPI, a coating weight of 5 g / m² to 8 g / m², and a coating speed of 60 m / min to 150 m / min;

[0037] And / or, in the peeling step, the peeling speed is 30 m / min to 75 m / min;

[0038] And / or, the peeling angle is 120° to 150°.

[0039] In one embodiment, the photolithographic film with a three-dimensional texture is prepared before the hot pressing and photocuring steps, including the following steps:

[0040] Photolithography master is used to create transfer textures;

[0041] Apply functional adhesive to the substrate;

[0042] The substrate pre-cured and coated with the functional adhesive;

[0043] The substrate and the master plate after hot pressing and pre-curing;

[0044] Photopolymerize the substrate and the master plate;

[0045] Peel off the substrate and the master plate.

[0046] In one embodiment, the photolithography wavelength is 360nm to 370nm, and / or the photolithography power is 80W to 120W, and / or the photolithography resolution is 1900dpi to 2100dpi;

[0047] And / or, the material of the substrate includes a polyester film;

[0048] And / or, the material of the functional adhesive includes 65% to 70% polyurethane elastic resin, 8% to 10% silicone wear-resistant additive, 3% to 4% crosslinking agent, and 18% to 22% diluent;

[0049] And / or, the dry film thickness formed after the substrate is coated with the functional adhesive is 8μm to 12μm;

[0050] And / or, the speed of applying the functional adhesive is 50 m / min to 60 m / min;

[0051] And / or, the pre-curing temperature is 50℃~60℃, and / or, the pre-curing time is 10s~20s;

[0052] And / or, the hot pressing pressure is 0.3MPa~0.5MPa, and / or, the hot pressing temperature is 55℃~65℃, and / or, the hot pressing speed is 40m / min~50m / min;

[0053] And / or, the power of light curing is 110W / cm to 120W / cm, and / or, the light curing time is 3s to 5s;

[0054] And / or, the substrate is dusted before the step of coating the functional adhesive onto the substrate;

[0055] And / or, after the step of peeling off the substrate and the master, allow the peeled substrate to stand and mature.

[0056] In one embodiment, the packaging substrate is leveled prior to the coating step.

[0057] In one embodiment, the process of smoothing the packaging substrate includes the following steps: printing the packaging substrate, and / or applying a base coat to the packaging substrate.

[0058] The aforementioned aluminum-free packaging substrate and packaging base material serve as the load-bearing foundation, with an aluminum-free reflective layer on its surface. This reflective layer itself forms a three-dimensional structure. When light shines on the surface of the aluminum-free reflective layer, the three-dimensional structure refracts and scatters the light at multiple angles, continuously altering the light propagation path. As the viewing angle changes, the incident angle of the light changes synchronously, and the light propagation path dynamically switches, forming dynamic, dazzling light and shadow effects, achieving rich and vibrant visual effects. Because the three-dimensional structure is formed from a portion of the aluminum-free reflective layer, it avoids problems such as cracking, powdering, and delamination that occur with traditional layered aluminum-coated films. This makes the vibrant effect of the aluminum-free packaging substrate more stable, while also improving its scratch resistance, bending resistance, waterproof and moisture-proof performance, and extending its service life. Thus, the aluminum-free packaging substrate can have rich colors, abundant visual layers, and dynamic visual effects, thereby matching the differentiated design needs of products and making aluminum-free packaging products more environmentally friendly. Attached Figure Description

[0059] To more clearly illustrate the technical solutions in the embodiments of this application or the conventional technology, the drawings used in the description of the embodiments or the conventional technology will be briefly introduced below. Obviously, the drawings described below are only embodiments of this application. For those skilled in the art, other drawings can be obtained based on the disclosed drawings without creative effort.

[0060] Figure 1 This is a cross-sectional view of an aluminum-free packaging substrate provided in an embodiment of this application.

[0061] Figure 2 for Figure 1 Enlarged diagram of point A in the middle.

[0062] Figure 3 A cross-sectional view of another aluminum-free packaging substrate provided in an embodiment of this application.

[0063] Figure 4 A cross-sectional view of another aluminum-free packaging substrate provided in an embodiment of this application.

[0064] Figure 5 This is a cross-sectional view of another aluminum-free packaging substrate provided in the embodiments of this application.

[0065] Figure 6 A cross-sectional view of another aluminum-free packaging substrate provided in this application embodiment.

[0066] Figure 7 This is a schematic diagram of the structure of a packaging bag provided in an embodiment of this application.

[0067] Figure 8 This is a schematic diagram of the structure of another packaging bag provided in an embodiment of this application.

[0068] Figure 9 A flowchart illustrating a method for manufacturing an aluminum-free packaging substrate, as provided in this application embodiment.

[0069] Explanation of reference numerals in the attached drawings: 100, aluminum-free packaging substrate; 1, packaging base material; 2, base coating; 3, aluminum-free reflective layer; 31, three-dimensional structure; 311, protrusion; 312, recess; 200, packaging bag; 201, storage cavity; 202, opening; 203, handle. Detailed Implementation

[0070] To make the above-mentioned objectives, features, and advantages of this application more apparent and understandable, the specific embodiments of this application are described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a thorough understanding of this application. However, this application can be implemented 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 this application. Therefore, this application is not limited to the specific embodiments disclosed below.

[0071] Current packaging materials are limited in color, have monotonous visual layers, lack dynamic visual effects, and are difficult to match the differentiated design needs of products.

[0072] In this embodiment, the first direction refers to the thickness direction of the packaging substrate 1. Figures 1 to 6 Direction A is shown. The second direction intersects the first direction, which is the length or width direction of the packaging base material 1. Figures 1 to 6 The direction shown is B.

[0073] Based on the above issues, please refer to Figure 1 In a first aspect, embodiments of this application provide an aluminum-free packaging substrate 100, including a packaging base material 1 and an aluminum-free reflective layer 3. The aluminum-free reflective layer 3 is disposed on at least a portion of one side surface of the packaging base material 1 along a first direction, where the first direction is the thickness direction of the packaging base material 1. At least a portion of the side surface of the aluminum-free reflective layer 3 facing away from the packaging base material 1 has a three-dimensional structure 31, which is used to change the light propagation path. The packaging base material 1 serves as a supporting foundation, and the aluminum-free reflective layer 3, combined with the three-dimensional structure 31, enables the aluminum-free packaging substrate 100 to have a dazzling effect. A portion of the aluminum-free reflective layer 3 itself forms the three-dimensional structure 31. When light shines onto the surface of the aluminum-free reflective layer 3, the three-dimensional structure 31 refracts and scatters the light at multiple angles, continuously changing the light propagation path. When the viewing angle changes, the incident angle of the light changes synchronously, and the light propagation path dynamically switches, forming dynamic dazzling light and shadow, achieving rich and vibrant visual effects. This allows for a rich variety of colors and visual layers in the aluminum-free packaging substrate 100, creating a dynamic visual effect that can match the differentiated design needs of products.

[0074] The three-dimensional structure 31 is formed by a portion of the aluminum-free reflective layer 3 itself, making the aluminum-free reflective layer 3 a single layer, unlike the traditional method of adding an aluminum-plated film to the surface of the packaging substrate 1 to form a multi-layer structure. Multi-layer aluminum-plated film structures are prone to defects such as interlayer separation, film cracking, and surface powdering. However, the aluminum-free reflective layer 3 of this embodiment avoids the above problems at the source. The three-dimensional structure 31 formed by a portion of the aluminum-free reflective layer 3 itself not only ensures that the colorful visual effect of the aluminum-free packaging substrate 100 remains stable for a long time, but also has stronger overall structural continuity, effectively improving the scratch resistance, bending resistance, and waterproof and moisture-proof capabilities of the aluminum-free packaging substrate 100, and extending the overall service life of the product.

[0075] It is understood that the aluminum-free reflective layer 3 is disposed on at least a portion of one side surface of the packaging substrate 1 along the first direction. The aluminum-free reflective layer 3 may be disposed on the packaging substrate 1 in the following ways: Please refer to... Figure 1 The aluminum-free reflective layer 3 is disposed over the entire area of ​​one side surface of the packaging substrate 1 along the first direction. Please refer to [link / reference]. Figure 3 Alternatively, the aluminum-free reflective layer 3 may be disposed on a portion of one side surface of the packaging substrate 1 along the first direction. Please refer to [link / reference]. Figure 4 Alternatively, the aluminum-free reflective layer 3 may be disposed on both sides of the packaging substrate 1 along the first direction, covering the entire area of ​​one side surface and a portion of the other side surface. Please refer to [link / reference]. Figure 5 Alternatively, the aluminum-free reflective layer 3 may be disposed on both sides of the packaging substrate 1 along the first direction, and both sides may cover the entire area of ​​both sides. Please refer to [link / reference]. Figure 6 Alternatively, the aluminum-free reflective layer 3 can be disposed on both sides of the packaging substrate 1 along the first direction, and each side can be located in a portion of the surface. When the aluminum-free reflective layer 3 is disposed on the entire surface of any one of the packaging substrate 1 along the first direction, the packaging substrate 1 can have a full-color application. When the aluminum-free reflective layer 3 is disposed on a portion of any one of the surfaces of the packaging substrate 1 along the first direction, the packaging substrate 1 can have a partial color application.

[0076] At least a portion of the surface of the aluminum-free reflective layer 3 facing away from the packaging substrate 1 is provided with a three-dimensional structure 31. The three-dimensional structure 31 is provided on the aluminum-free reflective layer 3 in the following ways: the entire surface of the aluminum-free reflective layer 3 facing away from the packaging substrate 1 is provided with a three-dimensional structure 31, or a portion of the surface of the aluminum-free reflective layer 3 facing away from the packaging substrate 1 is provided with a three-dimensional structure 31.

[0077] The structure of the packaging base material 1 and the aluminum-free reflective layer 3 will be described below:

[0078] The packaging substrate 1 may be made of plant fibers, such as wood pulp, hemp, bamboo, cotton, etc., or biodegradable materials such as PLA (Polylactic Acid) and PBS (Poly-Butylene-Succinate). When the packaging substrate 1 is paper-based, it may specifically include white cardboard, coated paper, art cardboard, kraft paper, etc.

[0079] The packaging base material 1 can be white or other colors. Different shapes and sizes of patterns can be printed on the packaging base material 1 at different locations according to design requirements. For example, logos, brand logos, product models, warning graphics, decorative patterns, etc. can be printed on it.

[0080] Please see Figure 1 In some embodiments, the thickness of the packaging base material 1 along the first direction is H1, satisfying: 0.05mm ≤ H1 ≤ 0.5mm. When H1 is less than 0.05mm, the packaging base material 1 is relatively soft and easily deformed; when H1 is greater than 0.5mm, the packaging base material 1 is relatively hard and not conducive to bending. Controlling H1 within the above range allows the packaging base material 1 to have both suitable stiffness and flexibility. H1 can be any value within the above range, for example, it can be 0.05mm, 0.1mm, 0.2mm, 0.3mm, 0.35mm, 0.4mm, 0.5mm, etc.

[0081] In some embodiments, the moisture content of the packaging substrate is 6% to 8%. When the moisture content of the packaging substrate 1 is below 6%, it becomes brittle and easily breaks; when the moisture content is above 8%, it warps due to moisture, affecting the fabrication of the three-dimensional structure 31. Controlling the moisture content of the packaging substrate 1 within the above range prevents brittleness due to excessively low moisture content and warping due to excessively high moisture content. This provides a relatively flat substrate for the fabrication of the aluminum-free reflective layer 3 and the three-dimensional structure 31, which is beneficial for the fabrication of both.

[0082] The moisture content can be any value within the above range, such as 6%, 6.2%, 6.5%, 7%, 7.3%, 7.7%, 8%, etc.

[0083] The aluminum-free reflective layer 3 can be made of metal-free coatings such as UV (Ultraviolet) varnish. UV varnish is also known as ultraviolet-cured varnish. The components of UV varnish include 38%–42% modified epoxy acrylic resin, 25%–28% polyurethane acrylic resin, 15%–18% monofunctional reactive diluent, 8%–10% difunctional reactive diluent, 3%–4% ultraviolet photoinitiator, 1.5%–2.5% nano-silica light-diffusing agent, 0.3%–0.5% leveling agent, and 0.2%–0.5% defoamer.

[0084] The aluminum-free reflective layer 3, made with UV varnish, contains no metal, which is environmentally friendly. When the packaging substrate 1 uses biodegradable materials such as paper, the combination with the metal-free aluminum-free reflective layer 3 makes the entire aluminum-free packaging substrate 100 biodegradable and recyclable, further enhancing its environmental friendliness. The aluminum-free packaging substrate 100 does not employ vacuum metallization or metal vapor deposition processes, eliminating the need for energy-intensive metallization equipment and procedures, thus reducing production costs.

[0085] Please see Figure 1 In some embodiments, the thickness of the aluminum-free reflective layer 3 along the first direction is H2, satisfying: 6μm ≤ H2 ≤ 10μm. It can be understood that thickness H2 refers to the overall thickness of the dry film formed after the aluminum-free reflective layer 3 has cured. Controlling H2 within the above range ensures sufficient thickness of the aluminum-free reflective layer 3, providing a foundation for the fabrication of the three-dimensional structure 31. This thickness range improves the uniformity of curing of the aluminum-free reflective layer 3, reducing the problem of surface curing while the interior remains uncooked. Furthermore, this thickness range balances the hardness and flexibility of the aluminum-free reflective layer 3, preventing cracking and delamination when the aluminum-free packaging substrate 100 is repeatedly bent.

[0086] The thickness H2 of the aluminum-free reflective layer 3 can be any value within the above range, such as 6μm, 6.8μm, 7.5μm, 8μm, 8.7μm, 9.2μm, 10μm, etc.

[0087] The three-dimensional structure 31 of the aluminum-free reflective layer 3 refers to the microstructure located on the outer surface of the aluminum-free reflective layer 3, which can refract, reflect, and scatter incident light, thereby changing the propagation path of the light. The three-dimensional structure 31 can have morphologies such as corrugated, wrinkled, wavy, island-like, textured, porous, and mesh-like.

[0088] The number of three-dimensional structures 31 may be multiple. Multiple three-dimensional structures 31 may be scattered on the surface of the aluminum-free reflective layer 3, or the three-dimensional structures 31 may be continuously distributed on the surface of the aluminum-free reflective layer 3.

[0089] Please see Figure 2In some embodiments, the three-dimensional structure 31 includes multiple protrusions 311 and multiple recesses 312, with each protrusion 311 and each recess 312 adjacent to each other along a second direction. It is understood that a protrusion 311 refers to the raised portion of the three-dimensional structure 31, and a recess 312 refers to the recessed portion of the three-dimensional structure 31. The adjacent protrusions 311 and recesses 312 form a continuous and uninterrupted convex-concave morphology. When light shines, it alternately passes through the protrusions 311 and recesses 312. The protrusions 311 and recesses 312 have different angles of refraction and scattering of light, which can increase the number and area of ​​light impact points, reduce problems such as light and shadow breaks and missing light and shadow, and improve the consistency of the dazzling effect. At the same time, the continuously arranged protrusions 311 and recesses 312 can disperse the surface stress of the aluminum-free reflective layer 3. When the aluminum-free packaging substrate 100 is bent or rubbed, the three-dimensional structure 31 is not prone to local damage and detachment, which can improve the overall structural stability and service life of the aluminum-free packaging substrate 100.

[0090] Please see Figure 3 In some embodiments, along the first direction, the distance between the top of the adjacent protrusion 311 and the bottom of the recess 312 is h, satisfying: 0.8μm≤h≤1.2μm. It can be understood that the distance h refers to the vertical distance between the lowest point of the recess 312 and the highest point of its adjacent protrusion 311, which is also the depth of the three-dimensional structure 31. When h is less than 0.8μm, h is too small, the undulations of the three-dimensional structure 31 are weak, the effect of changing the light propagation path is poor, and the dazzling effect is not obvious; when h is greater than 1.2μm, the undulations of the three-dimensional structure 31 are large, easily producing glaring reflections and surface stress concentration, making it prone to damage during use. Controlling h within the range of 0.8μm to 1.2μm can balance optical effects and structural strength.

[0091] The spacing h can be any value within the above range, such as 0.8μm, 0.85μm, 0.9μm, 1.0μm, 1.05μm, 1.1μm, 1.2μm, etc.

[0092] Please see Figure 2Along the second direction, the center-to-center distance between adjacent protrusions 311 and recesses 312 is d, satisfying that d is greater than or equal to 1.5 μm. It can be understood that the center-to-center distance d can range from micrometers to centimeters, referring to the straight-line distance between the geometric centers of adjacent protrusions 311 and recesses 312 along the second direction. When d is less than 1.5 μm, the arrangement of protrusions 311 and recesses 312 is too dense, causing light interference and resulting in chaotic light and shadow. By controlling d within the above range, sufficient light refraction and scattering points are available per unit area of ​​the three-dimensional structure 31, enabling multi-angle gradient color effects and ensuring optical quality. Furthermore, controlling d within the above range improves the morphological integrity of the three-dimensional structure 31 during fabrication, reducing issues such as adhesion or incompleteness, thus enhancing the overall integrity of the three-dimensional structure 31 fabrication.

[0093] The center-to-center spacing d can be any value within the above range, such as 1.5μm, 1.6μm, 1.7μm, 1.8μm, 1.85μm, 1.9μm, 2.0μm, 1cm, 2cm, 3cm, 4cm, etc.

[0094] Please see Figure 2 In some embodiments, the surface of the protrusion 311 is curved, and / or the surface of the recess 312 is curved. It is understood that the protrusion 311 and the recess 312 can be configured in several ways: the surface of the protrusion 311 is curved, while the surface of the recess 312 is flat. Alternatively, the surface of the protrusion 311 is flat, while the surface of the recess 312 is curved. Or, the surface of the protrusion 311 is curved, and the surface of the recess 312 is also curved. Thus, the rounded edges of the recess 312 and the protrusion 311 can disperse stress, improving the bending resistance, scratch resistance, and service life of the aluminum-free packaging substrate 100, and avoiding stress generated by sharp edges, which are prone to cracking, chipping, or detachment under stress or wear. Furthermore, the curved surfaces of the recess 312 and the protrusion 311 refract light more softly, reducing the generation of glaring reflective points. At the same time, the surfaces of the recessed portion 312 and the protruding portion 311 are curved, which can be adapted to the manufacturing process of the three-dimensional structure 31, and can make the shape of the three-dimensional structure 31 more complete during the manufacturing process.

[0095] Please see Figure 2In some embodiments, the cross-sectional area of ​​the protrusion 311, parallel to the second direction, gradually increases from its top to its bottom. In some embodiments, the cross-sectional area of ​​the recess 312, parallel to the second direction, gradually increases from its top to its bottom. Thus, the cross-section of the protrusion 311 gradually widens, while the recess 312 gradually narrows. This gradual structure can lengthen the propagation path of light within the three-dimensional structure 31, enhancing the effect of altering the light propagation path. Furthermore, the gradually changing structure of the recess 312 and the protrusion 311 can adapt to the manufacturing process of the three-dimensional structure 31, resulting in a more complete morphology of the three-dimensional structure 31.

[0096] In some other embodiments, the cross-sectional area of ​​the protrusion 311 in the second direction is the same from its top end to its bottom end, forming a column with a constant cross-section. The cross-sectional area of ​​the recess 312 in the second direction is the same from its top end to its bottom end, forming a groove with a constant cross-section.

[0097] Please see Figure 1 In some embodiments, the aluminum-free packaging substrate 100 further includes a base coating 2, which is at least partially disposed between the packaging substrate 1 and the aluminum-free reflective layer 3 along a first direction. The base coating 2 is a transition layer disposed between the packaging substrate 1 and the aluminum-free reflective layer 3, and is made by applying and drying water-based varnish or water-based paint. It is used to smooth the packaging substrate 1 and improve interlayer adhesion. When there are pores or minor unevenness on the surface of the packaging substrate 1, the base coating 2 can fill the pores, smooth the surface defects of the packaging substrate 1, give the packaging substrate 1 a smooth surface, improve the flatness of the packaging substrate 1, and enable more uniform fabrication of the aluminum-free reflective layer 3. As a transition, the base coating 2 can improve the bonding strength between the packaging substrate 1 and the aluminum-free reflective layer 3, while preventing moisture and impurities inside the packaging substrate 1 from penetrating to the aluminum-free reflective layer 3, reducing problems such as bubbling, discoloration, or delamination of the aluminum-free reflective layer 3.

[0098] The base coat 2 can be prepared using a water-based varnish base coat system, which includes 45%–50% water-based acrylic resin, 35%–40% deionized water, 1.5%–2.5% water-based wetting and dispersing agent, 0.5%–1% water-based defoamer, 3%–5% film-forming aid, and 0.5%–1% thickener. Alternatively, the base coat 2 can be prepared using a water-based paint base coat system, which includes 40%–45% water-based polyurethane resin, 8%–12% ultrafine titanium dioxide, 38%–42% deionized water, 2% dispersant, 0.8% defoamer, and 2.2% film-forming aid.

[0099] Please see Figure 1 and Figure 5The base coating 2 can be integrally sandwiched between the packaging substrate 1 and the aluminum-free reflective layer 3; in other words, the base coating 2 is applied to the entire area of ​​the packaging substrate 1 and the aluminum-free reflective layer 3. Alternatively, please refer to... Figure 3 and Figure 6 When the packaging base material 1 has an aluminum-free reflective layer 3 only in a localized area, the base coating layer 2 can be applied only below the corresponding area of ​​the aluminum-free reflective layer 3, without applying it to the remaining areas, thus saving raw materials. Alternatively, a cross-area arrangement can be used; please refer to [link / reference needed]. Figure 4 Part of the base coating 2 is located between the packaging substrate 1 and the aluminum-free reflective layer 3, while the other part directly covers the exposed surface of the packaging substrate 1 where the aluminum-free reflective layer 3 is not located. Please refer to [link / reference]. Figure 4 , Figure 5 and Figure 6 The base coating 2 can also be applied to the two surfaces of the packaging substrate 1 along the first direction to flatten both sides of the packaging substrate 1; it can also extend to cover the sides of the packaging substrate 1 to optimize the flatness of the packaging substrate edge.

[0100] Please see Figure 1 In some embodiments, the thickness of the base coating 2 along the first direction is H3, satisfying: 3μm≤H3≤5μm. It is understood that the thickness of the base coating 2 along the first direction refers to the overall thickness of the dry film formed after the base coating 2 has cured. By controlling H3 within the above range, the base coating 2 can fill the microscopic defects of the packaging substrate 1, improve the surface smoothness of the packaging substrate 1, and facilitate the uniform coating of the aluminum-free reflective layer 3. Furthermore, the base coating 2 within this thickness range has good flexibility and good interlayer adhesion, which can reduce delamination.

[0101] H3 can be any value within the above range, such as 3μm, 3.4μm, 3.8μm, 4μm, 4.2μm, 4.6μm, 5μm, etc.

[0102] Secondly, embodiments of this application also provide an aluminum-free packaging product, at least a portion of which includes the aluminum-free packaging substrate 100 as described in the first aspect. The aluminum-free packaging product is obtained by processing the aluminum-free packaging substrate 100 through steps such as cutting, folding, and bonding. The aluminum-free packaging product can be a paper bag, gift box, packaging bag, envelope, bookmark, label, hang tag, bottle label, box label, etc. The aluminum-free packaging product can be fully colored or partially colored.

[0103] Aluminum-free packaging products are characterized by a 100% metal-free and aluminum-free substrate, enabling them to be biodegradable and recyclable. Their three-dimensional structure provides vibrant dynamic light and shadow effects, offering rich visual depth and meeting the needs of differentiated brand designs. Furthermore, the 100% scratch-resistant, bend-resistant, crack-resistant, and powder-free substrate ensures that the packaging products maintain a stable vibrant effect during handling and repeated use.

[0104] Please see Figure 7 and Figure 8 In some embodiments, the aluminum-free packaging product is a packaging bag 200. The packaging bag 200 has a storage cavity 201 and an opening 202 communicating with the storage cavity 201. The aluminum-free packaging substrate 100 surrounds and forms the storage cavity 201 and the opening 202. The aluminum-free packaging substrate 100 includes a packaging base material 1 and an aluminum-free reflective layer 3. At least a portion of the surface of the packaging base material 1 facing away from the storage cavity 201 is provided with the aluminum-free reflective layer 3. At least a portion of the surface of the aluminum-free reflective layer 3 facing away from the packaging base material 1 is provided with a three-dimensional structure 31. Packaging bag 200 is made using an aluminum-free packaging substrate 100. Packaging bag 200 features a multi-angle gradient rainbow color-changing effect. Due to the inclusion of a three-dimensional structure 31, the stability of the color-changing effect is improved, making the colors of packaging bag 200 more transparent and delicate, without problems such as metallic reflection and glare. The color consistency is high, with minimal batch-to-batch color difference, and the visual quality far surpasses traditional aluminum-plated laser processes. Furthermore, the three-dimensional structure 31 is structurally stable, preventing fading and darkening over long-term use. In addition, packaging bag 200 is aluminum-free and metal-free, achieving complete biodegradability and recyclability. By eliminating aluminum plating equipment and avoiding the energy-intensive aluminum plating process, the production process of packaging bag 200 is simplified, improving its yield and quality. The physical properties of packaging bag 200 are also effectively improved, with no issues such as film layer separation, cracking, or powder shedding. It can be repeatedly bent and has good scratch and fold resistance.

[0105] The layout structure of the packaging bag 200 in this application embodiment is adaptively adjusted to achieve full-page dazzling color, or to form a more precise dazzling color effect in certain areas.

[0106] Please see Figure 7 In some embodiments, the entire surface of the packaging base material 1 facing away from the storage cavity 201 is provided with an aluminum-free reflective layer 3, and the entire surface of the aluminum-free reflective layer 3 facing away from the packaging base material 1 is provided with a three-dimensional structure 31. In this way, the packaging bag 200 can achieve full-page dazzling color, so that the entire outer surface of the packaging bag 200 facing away from the storage cavity 201 has a multi-angle dazzling color effect.

[0107] Please see Figure 8 In some embodiments, a portion of the surface of the packaging base material 1 facing away from the storage cavity 201 is provided with an aluminum-free reflective layer 3, and a portion of the surface of the aluminum-free reflective layer 3 facing away from the packaging base material 1 is provided with a three-dimensional structure 31. In this way, localized iridescent effects can be achieved on the packaging bag 200, giving a multi-angle iridescent effect to a portion of the outer surface of the packaging bag 200 facing away from the storage cavity 201.

[0108] The packaging bag 200 may or may not have a handle 203. A handle 203 makes it easier for users to hold, pull, carry, and lift the bag, improving grip convenience. It can be used for hanging storage, saving storage space. At the same time, it can distribute the force between the bag opening and the bag body, reducing bag deformation and damage when lifting, and making it easier and less strenuous to pick up, put down, and transport.

[0109] Please see Figure 9Thirdly, this application provides a method for manufacturing an aluminum-free packaging substrate 100. The method includes: coating: applying a photocurable aluminum-free coating to a packaging substrate 1; drying: drying the packaging substrate 1 coated with the photocurable aluminum-free coating until the viscosity of the dried packaging substrate 1 is 0.8N to 1.2N; hot pressing and photocuring: hot pressing the three-dimensional texture of a photolithographic film onto the surface of the heat-treated packaging substrate 1 coated with the photocurable aluminum-free coating, while simultaneously performing photocuring; and peeling: peeling off the photolithographic film and the packaging substrate 1. It is understood that after the hot pressing and photocuring process, an aluminum-free reflective layer 3 can be formed on the packaging substrate 1, and a three-dimensional structure 31 is formed on the surface of the aluminum-free reflective layer 3 facing away from the packaging substrate 1. Neither the packaging substrate 1 nor the photocurable aluminum-free coating contains aluminum metal, avoiding the use of non-degradable aluminum film materials, enabling the finished aluminum-free packaging substrate 100 to be degradable and recyclable, which is beneficial to environmental protection. Drying removes the diluent from the interior of the photocurable aluminum-free coating, thereby controlling the surface tack. When the tack is maintained in the range of 0.8N to 1.2N, the photocurable aluminum-free coating is in a state of surface dryness and slight tack with sufficient plasticity. This allows it to replicate the three-dimensional texture of the photolithography film and create the three-dimensional structure 31 in subsequent hot pressing and photocuring processes. This reduces the risk of the three-dimensional structure 31 collapsing and becoming incomplete due to excessive hardness, and also reduces the risk of excessive adhesion to the photolithography film due to excessive tack, which can lead to residual adhesive, stringing, damage to the three-dimensional structure 31, and damage to the photolithography film during the peeling stage. This improves the quality and yield of the three-dimensional structure 31. After the drying step is completed, hot pressing and photocuring steps are performed simultaneously. Hot pressing allows the photocurable aluminum-free coating to fully fill the three-dimensional texture of the photolithography film, improving the integrity and compactness of the three-dimensional structure 31. Photocuring during hot pressing allows the photocurable aluminum-free coating to solidify and set while forming the three-dimensional structure 31, reducing problems such as deformation and collapse of the three-dimensional structure 31 caused by the rebound or flow of the photocurable aluminum-free coating. This improves the manufacturing accuracy of the three-dimensional structure 31 and allows the photocurable aluminum-free coating to form a dense structure, enhancing its adhesion and improving the overall abrasion resistance and bending resistance of the aluminum-free packaging substrate 100. After the hot pressing and photocuring steps are completed, the photolithography film and packaging substrate 1 are peeled off, leaving an aluminum-free reflective layer 3 formed by the photocurable aluminum-free coating on the surface of the packaging substrate 1. The three-dimensional structure 31 is formed on the aluminum-free reflective layer 3. Since the three-dimensional structure 31 is formed by the photocurable aluminum-free coating, it is directly formed on the aluminum-free reflective layer 3 and is not a separate layer, reducing defects such as delamination, cracking, or powdering. The entire manufacturing process does not use aluminum-containing processes such as vacuum aluminizing and metal vapor deposition, eliminating high-energy-consuming aluminum-using equipment and processes, and reducing production costs and processes.

[0110] It is understandable that a three-dimensional structure 31 is fabricated on the aluminum-free reflective layer 3 formed by photocuring aluminum-free coating. The three-dimensional structure 31 can refract and scatter incident light from multiple angles to form a dazzling visual effect. When the viewing angle changes, the incident angle of the light changes synchronously, and the light propagation path is dynamically switched to form a dazzling dynamic light and shadow.

[0111] In some embodiments, the packaging substrate 1 is made of a paper base. Using a paper base for the packaging substrate 1 facilitates processing and reduces costs.

[0112] In some embodiments, the packaging substrate 1 is leveled before the coating step. To reduce inherent defects such as porosity, unevenness, and warping in the packaging substrate 1, it can be pre-leveled to fill the pores, reduce surface unevenness and deformation, and form a continuous, smooth surface. Applying a UV-cured aluminum-free coating to this smooth surface reduces unevenness in the coating thickness, ensures uniform adhesion after heat treatment, improves the accuracy of fabricating the three-dimensional structure 31, and enhances the adhesion between the UV-cured aluminum-free coating and the aluminum-free substrate, reducing local delamination and improving the overall quality of the aluminum-free packaging substrate 100.

[0113] In some embodiments, the packaging substrate 1 is smoothed by the following steps: printing the packaging substrate 1, and / or applying a base coat to the packaging substrate 1.

[0114] In some embodiments, the material of the photocurable aluminum-free coating applied to the packaging substrate 1 includes 38%–42% modified epoxy acrylate resin, 25%–28% polyurethane acrylate resin, 15%–18% monofunctional reactive diluent, 8%–10% difunctional reactive diluent, 3%–4% UV photoinitiator, 1.5%–2.5% nano-silica light-diffusing agent, 0.3%–0.5% leveling agent, and 0.2%–0.5% defoamer. Modified epoxy acrylic resin and polyurethane acrylic resin serve as the main film-forming agents, enabling the coating to possess high hardness, strong adhesion, and excellent flexibility, reducing bending cracks. Monofunctional and difunctional reactive diluents can adjust the viscosity of the photocurable aluminum-free coating and participate in the crosslinking reaction. Ultraviolet photoinitiators can efficiently receive ultraviolet light to trigger the photocuring reaction. Nano-silica light-scattering agents enhance the light scattering effect, while leveling agents and defoamers eliminate defects such as bubbles and pinholes generated during coating.

[0115] The proportion of modified epoxy acrylate resin can be any value within the above range, such as 38%, 39%, 39.5%, 40%, 40.8%, 41.4%, 42%, etc. The proportion of polyurethane acrylate resin can be any value within the above range, such as 25%, 25.5%, 26%, 26.5%, 27%, 27.4%, 28%, etc. The proportion of monofunctional reactive diluent can be any value within the above range, such as 15%, 15.6%, 16.2%, 16.5%, 17%, 17.4%, 18%, etc. The proportion of bifunctional reactive diluent can be any value within the above range, such as 8%, 8.4%, 8.9%, 9%, 9.3%, 9.7%, 10%, etc. The proportion of ultraviolet photoinitiator can be any value within the above range, such as 3%, 3.2%, 3.4%, 3.5%, 3.7%, 3.8%, 4%, etc. The proportion of nano-silica light-diffusing agent can be any value within the above range, such as 1.5%, 1.7%, 1.9%, 2.0%, 2.2%, 2.3%, 2.5%, etc. The proportion of leveling agent can be any value within the above range, such as 0.3%, 0.33%, 0.37%, 0.4%, 0.42%, 0.46%, 0.5%, etc. The proportion of defoamer can be any value within the above range, such as 0.2%, 0.25%, 0.3%, 0.35%, 0.4%, 0.44%, 0.5%, etc.

[0116] A single-pass roll coating of UV-cured aluminum-free coatings can be applied using a screen roller with a line count of 100 LPI to 300 LPI, a coating weight of 5 g / m² to 8 g / m², and a coating speed of 60 m / min to 150 m / min. By matching the appropriate screen roller line count, coating weight, and coating speed, a UV-cured aluminum-free coating with uniform thickness and consistent surface can be formed, thus improving coating quality.

[0117] The screen roller line count can be any value within the above range, such as 100 LPI, 130 LPI, 170 LPI, 200 LPI, 230 LPI, 270 LPI, 300 LPI, etc. The coating amount can be any value within the above range, such as 5 g / m², 5.5 g / m², 6 g / m², 6.4 g / m², 7 g / m², 7.5 g / m², 8 g / m², etc. The coating speed can be any value within the above range, such as 60 m / min, 75 m / min, 90 m / min, 100 m / min, 120 m / min, 135 m / min, 150 m / min, etc.

[0118] During the drying step, the viscosity value of the dried packaging base material 1 can be any value within the above range, such as 0.8N, 0.85N, 0.9N, 1.0N, 1.05N, 1.1N, 1.2N, etc.

[0119] In some embodiments, the drying temperature is 75℃~85℃, and / or the drying time is 30s~40s, and / or the drying air velocity is 3m / s~5m / s. The drying temperature of 75℃~85℃ can stably volatilize the thinner of the photocurable aluminum-free coating, preventing premature curing or aging and embrittlement due to excessive temperature. The drying time of 30s~40s can ensure that the wet and dry state of the photocurable aluminum-free coating on the packaging substrate 1 is uniform. Combined with a stable air velocity of 3m / s~5m / s, it can avoid local differences in drying rate caused by airflow turbulence. The three factors work together to keep the viscosity of the photocurable aluminum-free coating stable within 0.8N~1.2N, so that the subsequent fabrication of the three-dimensional structure 31 can be relatively uniform and consistent, without damaging the structural strength of the packaging substrate 1.

[0120] In the drying step, the drying temperature can be any value within the above range, such as 75℃, 77℃, 79℃, 80℃, 82℃, 84℃, 85℃, etc. The drying time can be any value within the above range, such as 30s, 32s, 34s, 35s, 37s, 39s, 40s, etc. The drying air velocity can be any value within the above range, such as 3m / s, 3.2m / s, 3.5m / s, 4m / s, 4.2m / s, 4.7m / s, 5m / s, etc.

[0121] In some embodiments, during the hot pressing and photocuring steps, the photocuring process includes a first stage, a second stage, and a third stage performed sequentially. The photocuring wavelengths of the first, second, and third stages increase progressively, with the energy density of the second stage being greater than that of the first and third stages, respectively. The first stage of photocuring is used to achieve mild cross-linking and shaping of the surface layer of the photocured aluminum-free coating. This quickly terminates the flowability of the varnish, reducing the problems of extrusion flow and texture collapse of the photocured aluminum-free coating during hot pressing. At the same time, it retains appropriate micro-viscosity, ensuring complete texture replication and reducing problems such as photolithography film sticking and roughening. The second stage of photocuring enables deep cross-linking of the intermediate layer of the photocured aluminum-free coating, locking in the micro-texture and eliminating texture rebound deformation. At this stage, the photocured aluminum-free coating has a high degree of curing and stable demolding force, allowing for clean, residue-free peeling of the photolithography film. The precision of the three-dimensional structure 31 fabrication is stable, ensuring a high degree of consistency in the color effect of the entire batch of products. The third stage of photocuring enables complete cross-linking of the full-thickness varnish layer of the photocured aluminum-free coating, improving the overall curing degree, eliminating internal stress and post-shrinkage problems during coating curing, increasing the hardness of the formed aluminum-free reflective layer 3, and giving it stable physical properties such as resistance to thousands of bends, scratch resistance, and waterproof and moisture-proof properties, reducing defects such as later cracking, delamination, and darkening of the color.

[0122] In some embodiments, the hot-pressing temperature is 60℃~70℃, and / or the hot-pressing pressure is 0.4MPa~0.6MPa, and / or the hot-pressing speed is 35m / min~45m / min. A hot-pressing temperature of 60℃~70℃ is suitable because this temperature range enhances the plasticity of the photocurable aluminum-free coating, facilitating texture transfer, while preventing high-temperature damage to the packaging substrate 1 and the photolithography film. A hot-pressing pressure of 0.4MPa~0.6MPa ensures uniform texture transfer; too low a pressure results in a shallow three-dimensional structure 31 with poor color effects, while too high a pressure can break through the coating and damage the packaging substrate 1. A hot-pressing speed of 35m / min~45m / min is suitable for assembly line operations, balancing transfer accuracy and production efficiency.

[0123] The hot pressing temperature can be 60℃, 62℃, 65℃, 67℃, 70℃, 63℃, 68℃, etc.; the hot pressing pressure can be 0.4MPa, 0.43MPa, 0.5MPa, 0.54MPa, 0.6MPa, 0.47MPa, 0.56MPa, etc.; the hot pressing speed can be 35m / min, 37m / min, 40m / min, 42m / min, 45m / min, 38m / min, 43m / min, etc.

[0124] In some embodiments, the photocuring wavelength of the first segment is 362nm to 368nm, the energy density is 800mJ / cm² to 1200mJ / cm², the photocuring line power is 80W / cm² to 100W / cm², and the light intensity density is 600W / cm². 2 ~800W / cm 2 The curing time is 1.0s to 1.5s, and the light temperature is 50℃ to 55℃. The second stage has a photocuring wavelength of 382nm to 388nm, an energy density of 1800mJ / cm² to 2500mJ / cm², a photocuring line power of 120W / cm² to 150W / cm², and a light intensity density of 1000W / cm². 2 ~1200W / cm 2 The curing time is 1.5s to 2.0s, and the light temperature is 55℃ to 60℃. The third stage has a photocuring wavelength of 392nm to 398nm, an energy density of 1500mJ / cm² to 2200mJ / cm², a photocuring line power of 100W / cm² to 120W / cm², and a light intensity density of 800W / cm². 2 ~1000W / cm 2The curing time is 1.5s to 2.5s, and the temperature in the light-curing zone is less than or equal to 45℃. Thus, the total power of the first, second, and third stages of light curing is 300W / cm² to 370W / cm², the total curing time is 4.0s to 6.0s, and the total energy density is 4100mJ / cm² to 5900mJ / cm². The resulting aluminum-free reflective layer 3 with a three-dimensional structure 31 is non-sticky, bubble-free, pinhole-free, and free of orange peel defects. The light-curing wavelength within the above range increases progressively from the first to the third stage, allowing the aluminum-free coating to cure gradually from the surface inwards, avoiding problems such as surface drying but incomplete drying, and an overly brittle surface layer and a soft inner layer. Within the above range, the energy density, linear power, and light intensity density increase from the first to the second stage and then decrease from the second to the third stage. The first stage provides shaping and prevents sticking, the second stage precisely locks the texture to improve accuracy, and the third stage prevents high-temperature catalysis of the coating, balancing demolding performance, texture accuracy, and the physical properties of the finished product. The temperature and time within the above range can achieve precise three-stage temperature and time control, reduce uneven curing rate of the photocurable aluminum-free coating caused by local temperature fluctuations, reduce deformation of the three-dimensional structure 31, reduce yellowing of the aluminum-free reflective layer 3, and improve the consistency of the finished product.

[0125] In some embodiments, the peeling speed is 30 m / min to 75 m / min, and / or the peeling angle is 120° to 150° during the peeling step. After the hot pressing and photocuring steps, the photocured aluminum-free coating is cured, and its three-dimensional structure 31 is finalized. In the peeling step, the oblique peeling angle of 120° to 150° allows the peeling force to be applied evenly to the contact surface, avoiding concentrated tensile force tearing of the three-dimensional structure 31 caused by sharp-angle peeling, and also reducing the problem of sudden increase in resistance caused by large-angle peeling. The peeling speed of 30 m / min to 75 m / min can keep the peeling force stable, reduce the instantaneous tensile force change caused by speed fluctuations, and thus reduce defects such as roughening, residual adhesive, and structural damage on the surface of the three-dimensional structure 31.

[0126] The peeling speed can be any value within the above range, such as 30 m / min, 40 m / min, 50 m / min, 60 m / min, 70 m / min, 720 m / min, 75 m / min, etc. The peeling angle can be any value within the above range, such as 120°, 125°, 130°, 135°, 140°, 145°, 150°, etc.

[0127] In some embodiments, a photolithographic film with a three-dimensional texture is prepared before the hot pressing and photocuring steps, including the following steps: using a photolithographic master to create a transfer texture; coating a functional adhesive onto a substrate; pre-curing the substrate coated with the functional adhesive; hot-pressing the pre-cured substrate and master; photocuring the substrate and master; and peeling off the substrate and master.

[0128] Before the hot pressing and photocuring steps, a photolithographic film with a three-dimensional texture is prepared. Pre-fabricating a photolithographic film with a standardized three-dimensional texture allows for repeated transfer of uniform three-dimensional textures onto the surface of the photocurable aluminum-free coating on the packaging substrate 1, ensuring consistency in the three-dimensional structure 31 across different batches of products. Furthermore, the photolithographic film can be reused multiple times, eliminating the need to fabricate the three-dimensional structure 31 for each individual product, thus reducing the production cost of the photolithographic film and improving production efficiency.

[0129] Understandably, in the process of creating transfer textures using a photolithography master, photolithography, a micro-nano fabrication technology, can create transfer textures at the micron and nanometer scale on the master. The fine microscopic structure allows for multi-angle refraction and scattering of light, achieving better color effects. Furthermore, photolithography produces transfer textures with regular edges and uniform depth, improving processing precision. Additionally, photolithographic patterns can be digitally edited, flexibly creating full-page or partial transfer textures to meet diverse packaging design needs.

[0130] In some embodiments, the lithography wavelength is 360nm–370nm, the lithography power is 80W–120W, and the lithography resolution is 1900dpi–2100dpi. A lithography wavelength of 360nm–370nm ensures sharp edges on the etched lines, reduces smudging, and improves the contour accuracy of the transferred texture. A lithography power of 80W–120W allows for stable control of the etching depth of the transferred texture, preventing shallow etching due to insufficient power or over-etching due to excessive power, which could damage the transferred texture. The high resolution of 1900dpi–2100dpi allows for a denser arrangement of transferred texture units per unit area, resulting in a denser concentration of light refraction and reflection points, enhancing the multi-angle iridescent effect.

[0131] In the step of coating the substrate with the functional adhesive, in some embodiments, the substrate material is a polyester film, also known as a PET film. PET film is a dry film, not easily stretched or damaged, and can be reused, thereby reducing manufacturing costs.

[0132] In some embodiments, the functional adhesive comprises 65%–70% polyurethane elastic resin, 8%–10% silicone abrasion-resistant additive, 3%–4% crosslinking agent, and 18%–22% diluent. The polyurethane elastic resin, as the film-forming substance of the functional adhesive, enables the adhesive layer to possess high elasticity and flexibility, allowing it to fully deform and replicate the transfer texture of the master plate during bonding, and to spring back and retain its shape after peeling. The silicone abrasion-resistant additive improves the release properties and abrasion resistance of the functional adhesive, extending the service life of the photolithography film. The crosslinking agent enhances the structural strength and temperature resistance of the functional adhesive, and the diluent adjusts the viscosity of the functional adhesive, ensuring uniform coating.

[0133] In some embodiments, the dry film thickness formed by the functional adhesive is 8μm to 12μm. A dry film thickness of 8μm to 12μm balances the ability to replicate the transferred texture with structural stability, preventing breakage due to excessively thin functional adhesive or loss of structural details of the transferred texture due to excessively thick functional adhesive.

[0134] In some embodiments, the coating speed of the functional adhesive is 50 m / min to 60 m / min. A coating speed of 50 m / min to 60 m / min can ensure a uniform thickness of the functional adhesive.

[0135] In the step of pre-curing the substrate coated with functional adhesive, pre-curing can initially volatilize the diluent and allow the resin to cross-link slightly, turning the functional adhesive into a slightly viscous solid state and reducing problems such as adhesive flow and overflow in subsequent hot pressing processes.

[0136] In some embodiments, the pre-curing temperature is 50°C to 60°C, and / or the pre-curing time is 10s to 20s. The low temperature of 50°C to 60°C combined with the short pre-curing time of 10s to 20s achieves surface shaping of the functional adhesive while retaining sufficient plasticity inside, reducing hot-pressing overflow, and preventing the adhesive layer from completely curing and becoming unreplicable.

[0137] In the hot-pressing pre-cured substrate and master plate step, the pre-cured substrate and master plate are hot-pressed, and the remaining plastic transfer master plate texture is used to create a three-dimensional texture on the substrate, providing a template for the subsequent production of three-dimensional structure 31.

[0138] In some embodiments, the hot-pressing pressure is 0.3 MPa to 0.5 MPa, and / or the hot-pressing temperature is 55°C to 65°C, and / or the hot-pressing speed is 40 m / min to 50 m / min. The combination of the hot-pressing pressure of 0.3 MPa to 0.5 MPa, the hot-pressing temperature of 55°C to 65°C, and the hot-pressing speed of 40 m / min to 50 m / min allows the micro-adhesive functional adhesive to fully fill the transfer texture of the master plate and achieve uniform replication.

[0139] In the steps of photocuring substrate and master plate, the functional adhesive is deeply cross-linked through secondary curing to achieve hardening and shaping, which can reduce the possibility of springback or deformation of the textured structure after peeling.

[0140] In some embodiments, the photocuring power is 110W / cm to 120W / cm, and / or the photocuring time is 3s to 5s. The photocuring power of 110W / cm to 120W / cm combined with the photocuring time of 3s to 5s allows the functional adhesive to complete deep cross-linking, forming a dense and stable structure, while preventing the functional adhesive from becoming brittle and cracking due to excessive light energy, thus balancing the fabrication accuracy of the textured structure and the mechanical properties of the photolithography film.

[0141] In some embodiments, the substrate is dusted before the functional adhesive is applied. Dust removal before applying the functional adhesive prevents dust from forming raised defects on the substrate surface, reduces the amplification of imperfections by dust covering the adhesive layer, and minimizes texture issues such as white spots and pits. Dust removal can be achieved through electrostatic cleaning, high-pressure airflow blowing, negative pressure suction, or ultrasonic dust removal.

[0142] In some embodiments, after the step of peeling off the substrate and master, the peeled substrate is left to stand and mature. Standing maturation of the substrate allows the resin that has not fully cured to complete its residual cross-linking reaction, while simultaneously releasing the intramolecular stress within the functional adhesive. This reduces shrinkage, warping, and texture deformation of the photolithography film during subsequent use, effectively improving the yield and reusability stability of the photolithography film. Maturation can be achieved through methods such as low-temperature constant-temperature sealed maturation, ultraviolet irradiation maturation, slow maturation in a humidified environment, air-drying maturation with circulating air, and accelerated maturation with short-term heating. Typically, the substrate is left to stand and mature for 24 hours.

[0143] The embodiments of this application will be further explained below with examples and experimental test results:

[0144] Example 1

[0145] The photolithography master is used to create the transfer texture. The photolithography wavelength is 365nm, the photolithography power is 100W, and the photolithography resolution is 2000dpi.

[0146] Electrostatic dust removal is performed on the substrate, which is a polyester film.

[0147] A functional adhesive is coated onto a substrate. The material of the functional adhesive includes 68% polyurethane elastic resin, 9% silicone wear-resistant additive, 3.5% crosslinking agent, and 19.5% diluent. The coating speed of the functional adhesive is 55 m / min.

[0148] The substrate coated with the functional adhesive is pre-cured at a temperature of 55°C and / or for a time of 20 seconds.

[0149] The substrate and master plate are pre-cured by hot pressing. The hot pressing pressure is 0.4 MPa, the hot pressing temperature is 60℃, and the hot pressing speed is 45 m / min.

[0150] The photocurable substrate and master plate have a photocuring power of 120W / cm and a photocuring time of 4s.

[0151] Peel off the substrate and the master plate;

[0152] Substrate after being left to stand for 24 hours to mature and peel off;

[0153] The packaging substrate 1 was smoothed. A water-based varnish primer system was prepared using 48% water-based acrylic resin, 38% deionized water, 2% water-based wetting and dispersing agent, 0.8% water-based defoamer, 4.2% film-forming aid, and 1.0% thickener. After mixing, the mixture was stirred at 900 rpm for 25 minutes. After stirring, the mixture was filtered and set aside. The packaging substrate 1 was smoothed using a 200 LPI screen roller coating process. After roller coating, the substrate was placed in an oven for low-temperature drying at 85°C for 20 seconds.

[0154] Coating: Apply a UV-curable aluminum-free coating to packaging substrate 1. Packaging substrate 1 consists of a paper base. The UV-curable aluminum-free coating comprises 40% modified epoxy acrylic resin, 26.6% polyurethane acrylic resin, 16.5% monofunctional reactive diluent, 9% difunctional reactive diluent, 3.5% UV photoinitiator, 2% nano-silica light-diffusing agent, 0.4% leveling agent, and 0.4% defoamer. Mix the coating under light-protected and room temperature conditions for 30 minutes at a stirring speed of 1200 rpm. Filter and allow to stand for 10 minutes before use. Apply the UV-curable aluminum-free coating using a screen roller with a line count of 200 LPI and a coating weight of 6 g / m² at a coating speed of 100 m / min.

[0155] Drying: The packaging substrate 1 coated with light-cured aluminum-free coating is dried to a viscosity of 1.0N. The drying temperature is 80℃, the drying time is 35s, and the drying air velocity is 4m / s.

[0156] Hot pressing and photocuring: The three-dimensional texture of the photolithographic film is hot-pressed onto one side of the packaging substrate 1 coated with a photocurable aluminum-free coating after heat treatment, and photocuring is performed simultaneously. The photocuring process includes three sequential stages: a first stage, a second stage, and a third stage. The hot pressing temperature is 65℃, the hot pressing pressure is 0.5MPa, and the hot pressing speed is 40m / min. The photocuring wavelength of the first stage is 365nm, the energy density is 1000mJ / cm², the linear power of photocuring is 90W / cm, and the light intensity density is 700W / cm². 2 The curing time is 1 second, and the light temperature is 52℃. The second stage has a curing wavelength of 385nm, an energy density of 2200mJ / cm², a curing line power of 130W / cm², and a light intensity density of 1100W / cm². 2 The curing time is 1.7 seconds, and the light-curing temperature is 58℃. The third stage has a photocuring wavelength of 395 nm, an energy density of 2000 mJ / cm², a photocuring line power of 110 W / cm, and a light intensity density of 900 W / cm². 2 The curing time is 2 seconds, and the temperature in the light zone is 30℃.

[0157] Peeling: Peel the photolithography film and packaging substrate 1. In the peeling step, the peeling speed is 40m / min and the peeling angle is 135°.

[0158] Example 2

[0159] The difference between Example 2 and Example 1 is that the first step is not included in the photocuring step in Example 2.

[0160] Example 3

[0161] The difference between Example 3 and Example 1 is that the second step is not included in the light curing step in Example 3.

[0162] Example 4

[0163] The difference between Example 4 and Example 1 is that the third step is not included in the light curing step in Example 4.

[0164] Comparative Example 1

[0165] The difference between Comparative Example 1 and Example 1 is that Comparative Example 1 does not have a drying step.

[0166] Comparative Example 2

[0167] The difference between Comparative Example 2 and Example 1 is that Comparative Example 2 does not have a light curing step after drying.

[0168] Comparative Example 3

[0169] The difference between Comparative Example 3 and Example 1 is that Comparative Example 3 does not have a hot pressing step after drying.

[0170] Comparative Example 4

[0171] The difference between Comparative Example 4 and Example 1 is that Comparative Example 4 is first photocured and then hot-pressed.

[0172] Performance testing

[0173]

[0174] Table 1: Experimental data for each embodiment and comparative example

[0175] Compared to Example 1, Example 2 omits the first stage of photocuring. The first stage of photocuring is a surface pre-curing process. Without surface pre-curing, the UV varnish surface cannot undergo mild cross-linking and shaping, and the varnish's flow properties cannot be terminated in time. During hot pressing, the UV varnish is easily squeezed and flows, and the texture edges collapse. Simultaneously, no micro-adhesive protective layer is formed on the surface, leading to direct contact between the photolithography film and the UV varnish, which easily causes mold sticking and paper surface roughening problems, significantly reducing the stability of texture replication. Therefore, Example 1 shows better results than Example 2 in terms of texture depth error, gloss deviation, demolding adhesion rate, photolithography film loss, and finished product yield. Therefore, incorporating the first stage of photocuring enables rapid shaping of the UV varnish surface, preventing sagging and mold sticking, ensuring the integrity of the basic texture morphology, and reducing demolding defects and photolithography film loss.

[0176] Compared to Example 1, Example 3 omits the second UV curing process. The second UV curing process is the mid-layer texture locking curing process. Without the mid-layer deep cross-linking step, the mid-layer of the UV varnish cannot achieve a high degree of curing. The micro-texture lacks rigid support, making it prone to springback deformation under pressure. The demolding force cannot be stably controlled, and the texture forming accuracy and gloss uniformity decrease simultaneously. Therefore, Example 1 has better results than Example 3 in terms of texture depth error, texture integrity replication rate, gloss deviation, demolding performance, and finished product yield. Therefore, incorporating the second UV curing process enables mid-layer texture locking curing, deeply locking the micro-texture, eliminating springback problems, stabilizing the demolding force, and ensuring consistent texture accuracy and color effect across the entire batch of products.

[0177] Compared to Example 1, Example 4 omits the third stage of UV curing. The third stage of UV curing is a deep reinforcement curing process. Lacking deep, full cross-linking curing, the overall curing degree of the UV varnish is not high, and internal stress and post-shrinkage in the coating are not completely eliminated. Therefore, the coating's hardness, bending resistance, and aging resistance are inferior to Example 1. Consequently, Example 1 exhibits higher long-term color stability and bending resistance than Example 4, and its gloss transparency is also better. The inclusion of a third stage of UV curing achieves deep reinforcement curing, enabling full-thickness cross-linking of the varnish layer, improving coating hardness, bending resistance, and waterproofing / moisture resistance, and reducing defects such as later cracking, delamination, and color darkening.

[0178] Compared to Example 1, Comparative Example 1 eliminated the drying step after UV varnish coating. Without pre-drying, the varnish thinner did not fully evaporate, resulting in a surface viscosity far exceeding the standard 0.8N–1.2N range. This led to strong UV varnish flow, causing it to flow and collapse during hot pressing. Simultaneously, the UV varnish remained in a completely unset state, adhering to the photoresist film during curing. Therefore, Comparative Example 1 exhibited inferior texture replication accuracy, gloss uniformity, demolding effect, photoresist film loss, and finished product yield compared to Example 1, and also showed noticeable bright spots, dark spots, severe residual adhesive, and paper surface roughening. Therefore, incorporating a pre-drying step allows for precise control of the varnish surface viscosity to a slightly viscous state, balancing the varnish's plasticity and setting ability. This ensures texture transfer while reducing problems such as adhesion, sagging, and uneven gloss at the source.

[0179] Compared to Example 1, Comparative Example 2 only underwent hot pressing after drying, without a photocuring process. The UV varnish did not undergo resin cross-linking and remained in a highly viscous liquid state. The hot-pressed texture lacked curing and shaping support, resulting in rapid rebound and collapse under pressure. The coating had no hardness, extremely poor adhesion, and continued to adhere to the photolithography film. Therefore, Comparative Example 2 showed significantly lower texture replication rate, gloss uniformity, demolding performance, photolithography film loss, and finished product yield compared to Example 1. It exhibited large areas of uneven brightness, dark spots, residual adhesive throughout the plate, multiple roughening areas, and the coating was easily scratched upon contact. Therefore, incorporating photocuring during hot pressing allows the UV varnish to gradually cross-link and cure from the surface inwards, permanently shaping the texture and imparting hardness, adhesion, and physical protection to the coating.

[0180] Compared to Example 1, Comparative Example 3 only underwent photocuring after drying, without a hot-pressing process. Without the hot-pressing process, the photolithography film could not adhere tightly to the packaging substrate, resulting in gaps, air bubbles, and misalignment. Consequently, the three-dimensional texture of the photolithography film could not be transferred to the UV varnish surface, and after curing, a complete three-dimensional structure 31 was not achieved. Therefore, the texture forming accuracy, texture replication rate, and gloss uniformity of Comparative Example 3 were significantly inferior to those of Example 1. By incorporating a simultaneous hot-pressing process, the photolithography film can be fully adhered to the packaging substrate, allowing the UV varnish to fully fill the texture structure and achieve accurate transfer of the three-dimensional structure 31.

[0181] Compared to Example 1, Comparative Example 4 changed the process sequence, performing the photocuring process first, followed by the hot pressing process, with the hot pressing and photocuring processes not occurring simultaneously. The UV varnish was prematurely fully cross-linked and hardened, losing its plasticity and deformability. Subsequent hot pressing could not replicate the texture structure of the photolithography film, and the hot pressing directly squeezed and damaged the already cured coating surface, causing texture collapse, micro-cracks in the coating, and adhesive fragments leading to film adhesion. Therefore, Comparative Example 4's texture depth error, gloss uniformity, and demolding performance were inferior to Example 1. After photocuring, hot pressing resulted in surface texture deformation, localized bright streaks, and adhesive fragments remaining during peeling. Therefore, the process of simultaneous hot pressing and photocuring allows texture transfer to be completed while the UV varnish retains its plasticity, followed by simultaneous curing and shaping, avoiding texture damage and coating cracking problems caused by curing before rolling.

[0182] In the description of this application, it should be understood that if terms such as "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential" appear, these terms indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0183] Furthermore, where the terms "first" and "second" appear, these terms are for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined with "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, where the term "multiple" appears, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0184] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; 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 expressly limited. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0185] In this application, unless otherwise expressly specified and limited, the use of descriptions such as "above" or "below" the second feature indicates that the first and second features are in direct contact or indirect contact via an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. Similarly, "below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0186] It should be noted that if an element is referred to as being "fixed to" or "set on" another element, it can be directly on the other element or there may be an intervening element. If an element is considered to be "connected to" another element, it can be directly connected to the other element or there may be an intervening element. If so, the terms "vertical," "horizontal," "upper," "lower," "left," "right," and similar expressions used in this application are for illustrative purposes only and do not represent the only possible implementation.

[0187] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0188] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. An aluminum-free packaging substrate for making packaging bags, characterized in that, include: Packaging base material; An aluminum-free reflective layer is disposed on at least a portion of one side surface of the packaging substrate along a first direction, wherein the first direction is the thickness direction of the packaging substrate. At least a portion of the side surface of the aluminum-free reflective layer opposite to the packaging substrate has a three-dimensional structure, which is used to change the light propagation path.

2. The aluminum-free packaging substrate according to claim 1, characterized in that, The three-dimensional structure includes multiple protrusions and multiple recesses, with each protrusion and each recess adjacent to each other along a second direction, which intersects with the first direction.

3. The aluminum-free packaging substrate according to claim 2, characterized in that, Along the first direction, the distance between the top end of the protrusion and the bottom end of the recess connected adjacently is h, which satisfies: 0.3μm≤h≤1.2μm; And / or, the surface of the protrusion is curved; And / or, the surface of the recess is curved; And / or, the cross-sectional area of ​​the protrusion in the second direction gradually increases from the top of the protrusion to its bottom. And / or, the cross-sectional area of ​​the recessed portion in the second direction gradually increases from the top of the recessed portion to its bottom.

4. The aluminum-free packaging substrate according to any one of claims 1 to 3, characterized in that, The thickness of the packaging base material along the first direction is H1, which satisfies: 0.05mm≤H1≤0.5mm; And / or, the thickness of the aluminum-free reflective layer along the first direction is H2, satisfying: 3μm≤H2≤10μm.

5. The aluminum-free packaging substrate according to any one of claims 1 to 3, characterized in that, The aluminum-free packaging substrate also includes a base coating layer, which is at least partially disposed between the packaging substrate and the aluminum-free reflective layer along the first direction.

6. The aluminum-free packaging substrate according to claim 5, characterized in that, The thickness of the base coating along the first direction is H3, which satisfies: 3μm≤H3≤5μm.

7. An aluminum-free packaging product, characterized in that, At least a portion of the aluminum-free packaging article comprises the aluminum-free packaging substrate as described in any one of claims 1 to 6.

8. The aluminum-free packaging product according to claim 7, characterized in that, The aluminum-free packaging product is a packaging bag, which has a storage cavity and an opening communicating with the storage cavity. The aluminum-free packaging substrate surrounds and forms the storage cavity and the opening. The aluminum-free packaging substrate includes a packaging base material and an aluminum-free reflective layer. At least a portion of the surface of the packaging base material facing away from the storage cavity is provided with the aluminum-free reflective layer, and at least a portion of the surface of the aluminum-free reflective layer facing away from the packaging base material is provided with a three-dimensional structure.

9. The aluminum-free packaging product according to claim 8, characterized in that, The aluminum-free reflective layer is provided on the entire surface of the packaging substrate facing away from the storage cavity, and the three-dimensional structure is provided on the entire surface of the aluminum-free reflective layer facing away from the packaging substrate.

10. The aluminum-free packaging product according to claim 8, characterized in that, The aluminum-free reflective layer is provided on a portion of the surface of the packaging substrate facing away from the storage cavity, and the three-dimensional structure is provided on a portion of the surface of the aluminum-free reflective layer facing away from the packaging substrate.

11. A method for manufacturing an aluminum-free packaging substrate, characterized in that, include: Coating: Applying a UV-cured aluminum-free coating to the packaging substrate; Drying: The packaging substrate coated with the light-cured aluminum-free coating is dried so that the viscosity of the dried packaging substrate is 0.8N to 1.2N; Hot pressing and photocuring: The three-dimensional texture of the photolithography film is hot-pressed onto the side surface of the packaging substrate coated with the photocurable aluminum-free coating after heat treatment, and photocuring is performed simultaneously; Peeling: Peeling off the photolithography film and the packaging substrate.

12. The method for manufacturing an aluminum-free packaging substrate according to claim 11, characterized in that, The drying temperature is 75℃~85℃, and / or the drying time is 30s~40s, and / or the drying air velocity is 3m / s~5m / s.

13. The method for manufacturing an aluminum-free packaging substrate according to claim 11, characterized in that, The photocuring process includes a first stage, a second stage, and a third stage performed sequentially. The photocuring wavelengths of the first stage, the second stage, and the third stage increase progressively. The energy density of the second stage is greater than that of the first stage and the third stage, respectively.

14. The method for manufacturing an aluminum-free packaging substrate according to claim 13, characterized in that, The hot pressing temperature is 60℃~70℃, and / or the hot pressing pressure is 0.4MPa~0.6MPa, and / or the hot pressing speed is 35m / min~45m / min; And / or, the photocuring wavelength of the first segment is 362nm~368nm, the energy density is 800mJ / cm²~1200mJ / cm², the photocuring line power is 80W / cm~100W / cm, and the light intensity density is 600W / cm². 2 ~800W / cm 2 The curing time is 1.0s to 1.5s, and the temperature in the light zone is 50℃ to 55℃. And / or, the second segment has a photocuring wavelength of 382nm to 388nm, an energy density of 1800mJ / cm² to 2500mJ / cm², a photocuring line power of 120W / cm² to 150W / cm², and a light intensity density of 1000W / cm². 2 ~1200W / cm 2 The curing time is 1.5s to 2.0s, and the temperature in the light zone is 55℃ to 60℃. And / or, the photocuring wavelength of the third segment is 392nm~398nm, the energy density is 1500mJ / cm²~2200mJ / cm², the photocuring line power is 100W / cm~120W / cm, and the light intensity density is 800W / cm². 2 ~1000W / cm 2 The curing time is 1.5s to 2.5s, and the temperature of the light zone is less than or equal to 45℃.

15. The method for manufacturing an aluminum-free packaging substrate according to claim 11, characterized in that, The packaging substrate is made of paper; And / or, the material of the photocurable aluminum-free coating includes 38%–42% modified epoxy acrylic resin, 25%–28% polyurethane acrylic resin, 15%–18% monofunctional reactive diluent, 8%–10% difunctional reactive diluent, 3%–4% ultraviolet photoinitiator, 1.5%–2.5% nano-silica light-diffusing agent, 0.3%–0.5% leveling agent, and 0.2%–0.5% defoamer; And / or, the photocurable aluminum-free coating is applied using a screen roller with a screen roller count of 100 LPI to 300 LPI and a coating amount of 5 g / m² to 8 g / m². The coating speed is 60m / min to 150m / min; And / or, in the peeling step, the peeling speed is 30 m / min to 75 m / min; And / or, the peeling angle is 120° to 150°.

16. The method for manufacturing an aluminum-free packaging substrate according to claim 11, characterized in that, Before the hot pressing and photocuring steps, the photolithographic film with a three-dimensional texture is prepared, including the following steps: Photolithography master is used to create transfer textures; Apply functional adhesive to the substrate; The substrate pre-cured and coated with the functional adhesive; The substrate and the master plate after hot pressing and pre-curing; Photopolymerize the substrate and the master plate; Peel off the substrate and the master plate.

17. The method for manufacturing an aluminum-free packaging substrate according to claim 16, characterized in that, The photolithography wavelength is 360nm~370nm, and / or the photolithography power is 80W~120W, and / or the photolithography resolution is 1900dpi~2100dpi; And / or, the material of the substrate includes a polyester film; And / or, the material of the functional adhesive includes 65% to 70% polyurethane elastic resin, 8% to 10% silicone wear-resistant additive, 3% to 4% crosslinking agent, and 18% to 22% diluent; And / or, the dry film thickness formed after the substrate is coated with the functional adhesive is 8μm to 12μm; And / or, the speed of applying the functional adhesive is 50 m / min to 60 m / min; And / or, the pre-curing temperature is 50℃~60℃, and / or, the pre-curing time is 10s~20s; And / or, the hot pressing pressure is 0.3MPa~0.5MPa, and / or, the hot pressing temperature is 55℃~65℃, and / or, the hot pressing speed is 40m / min~50m / min; And / or, the power of light curing is 110W / cm to 120W / cm, and / or, the light curing time is 3s to 5s; And / or, the substrate is dusted before the step of coating the functional adhesive onto the substrate; And / or, after the step of peeling off the substrate and the master, allow the peeled substrate to stand and mature.

18. The method for manufacturing an aluminum-free packaging substrate according to any one of claims 11 to 17, characterized in that, Prior to the coating step, the packaging substrate is leveled.

19. The method for manufacturing an aluminum-free packaging substrate according to claim 18, characterized in that, The process of smoothing the packaging substrate includes the following steps: printing the packaging substrate, and / or applying a base coat to the packaging substrate.

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