An environment-friendly packaging box with an intelligent visual window and an integrated preparation method thereof

Abstract

This invention provides an environmentally friendly packaging box with a smart viewing window, comprising a box body, a closed viewing window on the side of the box, and the molding material of the box comprising, from the outside in, a barrier coating, a paper layer, and a functional film layer; the opening of the viewing window penetrates only through the barrier coating and the paper layer, and the functional film layer remains intact in the area covered by the opening, directly forming the closed bottom surface of the viewing window; the barrier coating is a water-based environmentally friendly coating, coated or laminated on the outer surface of the paper layer, and the paper layer and the functional film layer are bonded together by an adhesive layer; the functional film layer is a biodegradable film with oxygen and water vapor barrier properties, wherein smart indicator material is uniformly dispersed. While ensuring the functionality of the viewing window, this invention simultaneously improves the environmental performance, intelligence level, barrier performance, and production efficiency of the packaging.

Description

Technical Field

[0001] This invention relates to packaging technology in the fields of food and daily chemicals, specifically to an environmentally friendly packaging box with an intelligent viewing window and its integrated manufacturing method. Background Technology

[0002] Packaging boxes with viewing windows are widely used in the food and beverage packaging industry due to their advantages of allowing for a direct display of contents and enhancing the consumer experience. In the prior art, as described in Chinese patent application CN107618725A, a packaging box with a viewing window is disclosed, whose molding material comprises a three-layer structure from the outside in, consisting of a PE layer, a paper layer, and a PE film. This design employs a closed structure with windows in the paper layer and the outer PE layer, and the inner side is completely covered by a PE film to achieve waterproofing, moisture resistance, and leak-proofing.

[0003] However, this existing technical solution faces the following technical bottlenecks in practical applications and industry development trends:

[0004] 1. Immense Environmental Regulatory Pressure: This solution extensively uses polyethylene (PE) in multi-layered composites, resulting in a "paper-plastic composite" structure. This structure makes paper-plastic separation difficult during recycling, leading to packaging waste typically being incinerated or landfilled, resulting in extremely low recycling value. With the EU's Packaging and Packaging Waste Regulation (PPWR) requiring all packaging to be recyclable by 2030 and setting strict standards for the recycled material content in plastic packaging, existing plastic-containing packaging solutions face significant risks of market access restrictions. The industry urgently needs environmentally friendly, biodegradable, or easily recyclable alternatives.

[0005] 2. Limited functionality: Existing technologies only provide basic "contents observable" functionality, failing to offer deeper information such as product freshness, shelf life, or authenticity, thus making it difficult to meet consumers' growing demands for food safety and product traceability.

[0006] 3. Barrier and preservation performance needs improvement: Existing technology only uses ordinary PE film as the inner barrier layer, which has limited ability to block oxygen and water vapor. For liquid foods or highly sensitive contents that require long shelf life, there is a risk of insufficient preservation period.

[0007] 4. Cumbersome production process: Existing preparation methods involve multiple separate processes, multiple positioning and material transfers, which not only increases equipment investment and labor costs, but may also affect the accuracy and yield of the final product due to multiple positioning errors.

[0008] The industry has attempted to use water-based coatings to replace PE layers, but existing water-based coating packaging solutions do not include formulations or opening methods that can be used in conjunction with viewing window structures. Meanwhile, existing smart packaging indicator solutions are typically implemented as standalone patches, without functional integration with the packaging structure itself, resulting in high costs, the need for additional processes, and susceptibility to detachment.

[0009] Therefore, developing a new type of packaging box with a viewing window and its preparation method that can meet the current stringent environmental regulations, possess intelligent functions, and improve product quality and production efficiency has significant industrial value and practical application prospects. Summary of the Invention

[0010] This invention aims to overcome the shortcomings of existing technologies and provide an environmentally friendly packaging box with an intelligent viewing window and its integrated manufacturing method. The technical problem this invention seeks to solve is: how to improve the environmental performance, intelligence level, barrier properties, and production efficiency of packaging while ensuring the functionality of the viewing window.

[0011] This invention provides an environmentally friendly packaging box with an intelligent viewing window, including a packaging box body, a closed viewing window on the side of the packaging box, and the molding material of the packaging box from the outside to the inside includes a barrier coating, a paper layer and a functional film layer.

[0012] The opening of the viewing window only penetrates the barrier coating and the paper layer, and the functional film layer remains intact in the area covered by the opening and directly forms the closed bottom surface of the viewing window.

[0013] The barrier coating is a water-based environmentally friendly coating, which is applied or coated onto the outer surface of the paper layer. The paper layer and the functional film layer are bonded together by an adhesive layer.

[0014] The functional thin film layer is a biodegradable film with oxygen and water vapor barrier properties, in which a smart indicator material is uniformly dispersed. This indicator material can be directly observed through the viewing window to indicate the state of the contents by its color change without the need for an artificial light source or power source.

[0015] Preferably, the barrier coating is selected from one of the following two types of routes:

[0016] Route A: The barrier coating is a fully bio-based waterproof and oil-resistant coating, selected from PHA-based coatings or PLA-based coatings;

[0017] Route B: The barrier coating is selected from water-based acrylic coating or water-based polyurethane coating.

[0018] Preferably, the functional thin film layer is selected from PLA film, PBAT film, or PLA / PBAT blend film; the smart indicator material is a thermosensitive or gas-sensitive color-changing pigment dispersed in the thin film substrate, which forms an integrated structure with the thin film material in the substrate, and is not a surface coating or patch.

[0019] Preferably, the thickness of the functional thin film layer is 15-30 μm, wherein the content of the smart indicator material is 0.5%-5% of the total weight of the film.

[0020] This invention also provides a method for preparing the above-mentioned environmentally friendly packaging box with an intelligent viewing window, characterized by comprising the following steps:

[0021] (1) A water-based environmentally friendly barrier coating is applied or laminated onto the outer surface of the paper layer and cured to form a barrier coating;

[0022] (2) Print a pattern on the outer surface of the barrier coating and punch holes in the barrier coating and the paper layer to form a viewing window opening;

[0023] (3) The paper layer after step (2) is bonded to the functional film layer through an adhesive layer to form a composite paper roll with a viewing window;

[0024] (4) Using an integrated online production line, the composite material roll paper obtained in step (3) is directly transported to the die-cutting station for die-cutting to obtain a single sheet;

[0025] (5) The single sheet is glued into a box by a gluing machine to form a sleeve-type paper box;

[0026] (6) The sleeve-type paper box is filled by a filling machine and the bottom and top are heated and sealed to obtain a sealed packaging box;

[0027] The order of steps (2) and (3) cannot be interchanged.

[0028] Preferably, the water-based environmentally friendly barrier coating in step (1) is applied using ultrasonic spraying technology, with the ultrasonic nozzle having a frequency of 20-50kHz and a spraying distance of 10-30mm.

[0029] Preferably, the functional thin film layer in step (3) is subjected to corona treatment before composite to enhance its surface activity, and the power density of the corona treatment is 10-30 W·min / m².

[0030] Preferably, the integrated online production line in step (4) integrates a flexographic printing machine, a rotary die-cutting machine and an online visual inspection system.

[0031] Preferably, the die-cutting process in step (4) further includes trimming and folding the paper layer.

[0032] The beneficial effects of this invention are as follows:

[0033] 1. The outer barrier coating of the present invention provides waterproof and oil-proof properties, the middle paper layer provides structural strength, and the inner functional film layer simultaneously undertakes the triple functions of sealing and isolation, high barrier properties, and intelligent indication. This realizes the high efficiency of a single functional film layer, avoids the thickness accumulation and cost increase caused by layered independent functional layers, and produces a synergistic effect.

[0034] 2. The barrier coating solutions of this invention can be flexibly selected according to actual needs. Route A (PHA / PLA coating) is suitable for scenarios requiring industrial composting or complete biodegradation; Route B (water-based acrylic / polyurethane coating) is suitable for pulp recycling systems, enabling efficient removal during the pulping process without affecting pulp reuse. Both routes comply with global regulatory trends such as EU PPWR for "plastic reduction" and "recyclability," avoiding the risk of being unable to enter the market due to excessive plastic content.

[0035] 3. By integrating smart indicator materials into the functional film layer of the viewing window, consumers can directly determine whether the contents are fresh or spoiled by observing color changes, without the need for additional sensors or power sources. Simultaneously, the functional film layer undergoes anti-fogging treatment to ensure clear observation under various temperature and humidity conditions.

[0036] 4. The high-barrier functional film layer (such as PLA / PBAT blend film) used can effectively block oxygen and water vapor compared with ordinary PE film, significantly extending the shelf life of liquid food and other products.

[0037] 5. By integrating the production line and the non-interchangeable sequence of steps, printing, punching, lamination, die-cutting and other processes are combined into a continuous process, eliminating intermediate transfer and positioning errors, greatly improving production efficiency and yield, and reducing production costs. Attached Figure Description

[0038] Figure 1 This is the front view of the present invention.

[0039] The attached diagram is labeled as follows: packaging box 10, viewing window 14, barrier coating 13, paper layer 12, and functional film layer 11. Detailed Implementation

[0040] To further understand the features, technical means, and specific objectives and functions achieved by the present invention, the present invention will be described in further detail below with reference to specific embodiments and accompanying drawings.

[0041] Example 1: Recyclable Route (Water-based Acrylic Coating + PLA / PBAT Blend Functional Film + Smart Indicator)

[0042] like Figure 1 As shown, an environmentally friendly packaging box with a smart viewing window is constructed from the following materials from the outside in: a water-based acrylic barrier coating 12 (12 gsm), a backing paper (paper layer 12, 250 gsm), and a PLA / PBAT blend film (20 μm, containing 3% thermochromic pigment) – i.e., a functional film layer 11. A viewing window 14 is located on the side of the packaging box 10, with the opening penetrating only the water-based acrylic coating and paper layer 12. The PLA / PBAT film remains intact, forming the closed bottom surface of the viewing window. This film undergoes an anti-fogging treatment before molding. When the temperature of the contents exceeds a preset safety line (40°C), the viewing window area will change from colorless to red within ≤2 seconds. The packaging box 10 is manufactured using an integrated online production line (integrating a flexographic printing press, a rotary die-cutting machine, and an online visual inspection system).

[0043] Example 2: Full Degradation Route (PHA Coating + PBAT Film + Gas Sensing Indicator)

[0044] An environmentally friendly packaging box with a smart viewing window comprises, from the outside in, a PHA barrier coating (15gsm), a backing paper (paper layer, 300gsm), and a PBAT film (18μm, containing 1.5% gas-sensitive color-changing pigment). This gas-sensitive color-changing pigment is dispersed within the PBAT substrate and responds to changes in oxygen content within the packaging, displaying a warning color (changing from green to yellow) as the expiration date approaches.

[0045] Example 3: Intelligent Transformation of Traditional Coatings (Waterborne Polyurethane Coating + PLA Film + Temperature Sensitive Indicator)

[0046] An environmentally friendly packaging box with a smart viewing window is formed from the following materials from the outside in: a water-based polyurethane barrier coating (10 gsm), a backing paper (paper layer, 350 gsm), and a PLA film (15 μm, containing 5% thermosensitive color-changing pigment). The packaging box is manufactured using an integrated online production line with non-interchangeable steps. The functional film layer undergoes corona treatment (power density 20 W·min / m²) before lamination.

[0047] The embodiments described above merely illustrate the optimal implementation of the present invention, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements all fall within the scope of protection of the present invention. Therefore, the scope of protection of this patent should be determined by the appended claims.

Claims

1. An environmentally friendly packaging box with an intelligent viewing window, comprising a packaging box body (10), characterized in that, The packaging box (10) has a closed viewing window (14) on its side. The molding material of the packaging box (10) includes, from the outside to the inside, a barrier coating (13), a paper layer (12) and a functional film layer (11). The opening of the viewing window (14) only penetrates the barrier coating (13) and the paper layer (12), and the functional film layer (11) remains intact in the area covered by the opening and directly forms the closed bottom surface of the viewing window; The barrier coating (13) is a water-based environmentally friendly coating, which is coated or laminated on the outer surface of the paper layer (12). The paper layer (12) and the functional film layer (11) are bonded together by an adhesive layer. The functional thin film layer (11) is a biodegradable film with oxygen barrier and water vapor barrier properties, wherein a smart indicator material is uniformly dispersed. The indicator material can be directly observed by visual observation of its color change through the viewing window (14) to indicate the state of the contents without the need for artificial light source or power supply.

2. The environmentally friendly packaging box with an intelligent viewing window according to claim 1, characterized in that, The barrier coating (13) is selected from one of the following two routes: Route A: The barrier coating (13) is a fully bio-based waterproof and oil-resistant coating, selected from PHA-based coatings or PLA-based coatings; Route B: The barrier coating (13) is selected from water-based acrylic coatings or water-based polyurethane coatings.

3. The environmentally friendly packaging box with an intelligent viewing window according to claim 1, characterized in that, The functional thin film layer (11) is selected from PLA film, PBAT film or PLA / PBAT blend film; the intelligent indicator material is a thermosensitive color-changing pigment or a gas-sensitive color-changing pigment dispersed in the thin film substrate, which forms an integrated structure with the thin film material in the substrate, and is not a surface coating or patch.

4. The environmentally friendly packaging box with an intelligent viewing window according to claim 3, characterized in that, The thickness of the functional thin film layer (11) is 15-30 μm, wherein the content of the smart indicator material is 0.5%-5% of the total weight of the film.

5. A method for preparing a packaging box as described in any one of claims 1 to 4, characterized in that, Includes the following steps: (1) A water-based environmentally friendly barrier coating is applied or coated onto the outer surface of the paper layer (12) and cured to form a barrier coating (13). (2) Print a pattern on the outer surface of the barrier coating (13) and punch holes in the barrier coating (13) and the paper layer (12) to form a viewing window opening; (3) The paper layer (12) after step (2) is bonded to the functional film layer (11) by an adhesive layer to form a composite paper roll with a viewing window (14); (4) Using an integrated online production line, the composite material roll paper obtained in step (3) is directly transported to the die-cutting station for die-cutting to obtain a single sheet; (5) The single sheet is glued into a box by a gluing machine to form a sleeve-type paper box; (6) The sleeve-type paper box is filled by a filling machine and the bottom and top are heated and sealed to obtain a sealed packaging box; The order of steps (2) and (3) cannot be interchanged.

6. The preparation method according to claim 5, characterized in that, The water-based environmentally friendly barrier coating in step (1) is applied using ultrasonic spraying technology. The frequency of the ultrasonic nozzle is 20-50kHz, and the spraying distance is 10-30mm.

7. The preparation method according to claim 5, characterized in that, The functional thin film layer (11) in step (3) is first subjected to corona treatment to enhance its surface activity before composite. The power density of the corona treatment is 10-30 W·min / m².

8. The preparation method according to claim 5, characterized in that, The integrated online production line in step (4) integrates a flexographic printing machine, a rotary die-cutting machine and an online visual inspection system.

9. The preparation method according to claim 5, characterized in that, The die-cutting process in step (4) also includes trimming and folding the paper layer (12).

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