Moisture-proof composite corrugated paperboard

Abstract

The utility model discloses a kind of moisture-proof composite corrugated paperboard, it is related to corrugated paperboard field, specifically a kind of moisture-proof composite corrugated paperboard, including bottom layer moisture-proof layer, inner layer corrugated core layer, intermediate barrier layer, outer layer corrugated core layer and surface layer moisture-proof layer from inside to outside are sequentially arranged;The bottom layer moisture-proof layer is PET film kraft paper, the surface layer moisture-proof layer is PE film kraft paper, the intermediate barrier layer is aluminum foil composite paper, the inner layer corrugated core layer is melamine resin modified corrugated paper, the utility model solves the current corrugated paperboard surface using coating single waterproof coating or using single layer plastic film film coating, the moisture-proof effect of this single coating processing mode is limited, and easily failure due to abrasion;Although single layer film can block part liquid water, it is difficult to solve water vapor penetration problem, and interlayer is mostly starch adhesive, swelling peeling after meeting water, cannot satisfy the long-term use demand of high humidity environment problem.

Description

Technical Field

[0001] This utility model relates to the field of corrugated cardboard, specifically a moisture-proof composite corrugated cardboard. Background Technology

[0002] Corrugated cardboard, a packaging material composed of a corrugated core layer and a linerboard, is widely used in packaging applications in the food, electronics, and logistics sectors due to its lightweight, good cushioning performance, and low cost.

[0003] However, the main component of corrugated cardboard is plant fiber, which contains a large number of hydroxyl groups in its molecular structure, making it highly susceptible to absorbing moisture from the environment. In humid environments (such as the rainy season, high-humidity warehouses, and cold chain transportation), traditional corrugated cardboard will experience the following problems due to water absorption:

[0004] Poor moisture resistance: The moisture permeability of traditional corrugated cardboard usually exceeds 50g / (㎡・24h), and the water absorption rate can reach more than 30% in 24 hours. After moisture penetrates through the fiber gaps, it will cause the cardboard to soften and deform.

[0005] Structural strength drops sharply: After absorbing water, the supporting force of the corrugated core layer decreases significantly. After being placed in an environment of 30°C and 90% relative humidity for 72 hours, the compressive strength retention rate is often less than 60%, and the burst strength drops to less than 50%, which seriously affects the protective ability of the packaging.

[0006] Edges are prone to moisture penetration: After the cardboard is cut, the edges are exposed, and moisture can easily penetrate through the fiber gaps, causing the edges to fail before the whole package, further shortening the service life of the packaging.

[0007] To improve the moisture-proof performance of corrugated cardboard, existing methods involve coating the surface with a single waterproof coating or using a single-layer plastic film. However, the moisture-proof effect of a single coating is limited and it is prone to failure due to wear. While a single-layer film can block some liquid water, it is difficult to solve the problem of water vapor penetration. Furthermore, the layers are often bonded with starch adhesive, which is prone to swelling and peeling when exposed to water, making it unsuitable for long-term use in high-humidity environments.

[0008] Therefore, developing a composite corrugated cardboard with high moisture-proof performance has become the key to solving the pain points of existing technologies. Utility Model Content

[0009] The purpose of this invention is to provide a moisture-proof composite corrugated cardboard to solve the problems mentioned in the background art.

[0010] To achieve the above objectives, this utility model provides the following technical solution: a moisture-proof composite corrugated cardboard, comprising, from the inside out, a bottom moisture-proof layer, an inner corrugated core layer, an intermediate barrier layer, an outer corrugated core layer, and a top moisture-proof layer; the bottom moisture-proof layer is PET-coated kraft paper, the top moisture-proof layer is PE-coated kraft paper, the intermediate barrier layer is aluminum foil composite paper, the inner corrugated core layer is melamine resin-modified corrugated paper, and the outer corrugated core layer is phenolic resin-impregnated corrugated paper.

[0011] Preferably, the corrugations of the outer corrugated core layer and the inner corrugated core layer adopt a V-shaped structure.

[0012] Preferably, the corrugated core layers of the outer layer and the inner corrugated core layer are perpendicular to each other.

[0013] Preferably, the moisture-proof composite corrugated cardboard has a hot-melt butyl adhesive sealing layer at the cut edge, and the width of the hot-melt butyl adhesive sealing layer is 5-8mm.

[0014] Preferably, the hot melt butyl adhesive sealing layer is further covered with a PE heat shrink film, the thickness of which is 20 μm.

[0015] Preferably, the PE membrane of the surface moisture-proof layer is provided with an acrylic waterproof coating layer, the thickness of which is 5-10 μm.

[0016] Compared with the prior art, the beneficial effects of this utility model are:

[0017] In this invention, corrugated cardboard is formed by using a multi-layered composite structure that has been treated. The multi-layered structure works together to block moisture, and the hot-melt butyl rubber sealing layer can solve the problem of edge sealing and side leakage. The corrugated core layer is modified with resin, and the vertical flute direction forms cross support, which improves the resistance to deformation. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the overall structure of this utility model.

[0019] Figure 2 This utility model Figure 1 Enlarged view of point A in the middle.

[0020] Figure 3 This is an exploded view of the present invention.

[0021] In the diagram: 1. Bottom moisture-proof layer; 2. Inner corrugated core layer; 3. Middle barrier layer; 4. Outer corrugated core layer; 5. Top moisture-proof layer; 6. Hot melt butyl rubber sealing layer; 7. PE heat shrink film; 8. Acrylic waterproof coating layer. Detailed Implementation

[0022] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0023] All electronic components in this application are controlled by an external controller, and all electrical appliances in this application are powered by a stable power supply that is compatible with them.

[0024] Example 1

[0025] Please refer to Figure 1-3 As shown, this utility model provides a moisture-proof composite corrugated cardboard, comprising a bottom moisture-proof layer 1, an inner corrugated core layer 2, an intermediate barrier layer 3, an outer corrugated core layer 4, and a top moisture-proof layer 5 arranged sequentially from the inside out; the bottom moisture-proof layer 1 is PET-coated kraft paper, the top moisture-proof layer 5 is PE-coated kraft paper, the intermediate barrier layer 3 is aluminum foil composite paper, the inner corrugated core layer 2 is melamine resin modified corrugated paper, and the outer corrugated core layer 4 is phenolic resin impregnated corrugated paper.

[0026] The bottom moisture-proof layer 1 is made of 200g / m² PET-coated kraft paper (PET film thickness 12μm, kraft paper basis weight 188g / m²). The inner corrugated core layer 2 is made of 150g / m² corrugated base paper and impregnated with 10% melamine resin solution (impregnation time 30s, drying at 120℃ until moisture content ≤8%). The middle barrier layer 3 is made of 8μm aluminum foil and 120g kraft paper laminated with water-based polyurethane adhesive (lamination pressure 0.3MPa, temperature 60℃). The outer corrugated core layer 4 is made of 150g / m² corrugated base paper and impregnated with 8% melamine resin solution. The corrugated cardboard is impregnated with phenolic resin solution (impregnation time 25s, drying at 110℃ until moisture content ≤8%). The surface moisture-proof layer 5 is made of 200g / ㎡ kraft paper coated with PE (PE film thickness 25μm, coating temperature 180℃). The bottom moisture-proof layer 1, inner corrugated core layer 2, middle barrier layer 3, outer corrugated core layer 4, and surface moisture-proof layer 5 are laminated and pressed together with a two-component polyurethane adhesive (component A: isocyanate, component B: polyol, mass ratio 1:1.2, adhesive application amount 15g / ㎡). The lamination sequence is bottom moisture-proof layer 1 → inner corrugated core layer 2 → middle barrier layer 3 → outer corrugated core layer 4 → surface moisture-proof layer 5. The lamination pressure is 0.4MPa, the temperature is 70℃, and the curing time is 24h. Each layer of this corrugated cardboard can be moisture-proof, and the multi-layer moisture-proof can prevent moisture from penetrating the cardboard and entering the inside of the cardboard.

[0027] Specifically, the outer corrugated core layer 4 and the inner corrugated core layer 2 adopt a V-shaped corrugation structure; the corrugation directions of the outer corrugated core layer 4 and the inner corrugated core layer 2 are perpendicular to each other, and the corrugation of the outer corrugated core layer 4 and the inner corrugated core layer 2 is V-shaped (corrugation height 3.5mm, corrugation pitch 8mm). Because the corrugation directions of the outer corrugated core layer 4 and the inner corrugated core layer 2 are perpendicular, when the cardboard is subjected to force, the outer corrugated core layer 4 and the inner corrugated core layer 2 can improve the strength of the cardboard and are not easily deformed due to the different corrugation directions.

[0028] The moisture-proof composite corrugated cardboard has a hot-melt butyl adhesive sealing layer 6 at its cut edges, with a width of 5-8 mm. A PE heat-shrink film 7 is also wrapped around the hot-melt butyl adhesive sealing layer 6. The PE heat-shrink film 7 has a thickness of 20 μm, and its edges are sealed with hot-melt butyl adhesive (melting temperature 130℃). The hot-melt butyl adhesive sealing layer 6 has a width of 6 mm. The hot-melt butyl adhesive sealing layer 6 seals the edges of the cardboard, improving its moisture-proof effect. The PE heat-shrink film 7, covering the outside of the hot-melt butyl adhesive sealing layer 6, protects it and further enhances its moisture-proof effect.

[0029] Based on the above embodiments, specifically, an acrylic waterproof coating layer 8 is provided on the outside of the PE membrane of the surface moisture-proof layer 5. The thickness of the acrylic waterproof coating layer 8 is 5-10μm. The acrylic waterproof coating layer 8 can form another waterproof membrane on the outside of the surface moisture-proof layer 5, further improving the moisture-proof effect.

[0030] The contents not described in detail in this specification are existing technologies known to those skilled in the art.

[0031] Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A moisture-proof composite corrugated cardboard, characterized in that, It includes a bottom moisture-proof layer (1), an inner corrugated core layer (2), a middle barrier layer (3), an outer corrugated core layer (4), and a surface moisture-proof layer (5), arranged sequentially from the inside to the outside. The bottom moisture-proof layer (1) is PET coated kraft paper, the top moisture-proof layer (5) is PE coated kraft paper, the middle barrier layer (3) is aluminum foil composite paper, the inner corrugated core layer (2) is melamine resin modified corrugated paper, and the outer corrugated core layer (4) is phenolic resin impregnated corrugated paper.

2. The moisture-proof composite corrugated cardboard according to claim 1, characterized in that: The outer corrugated core layer (4) and the inner corrugated core layer (2) have a V-shaped corrugation structure.

3. The moisture-proof composite corrugated cardboard according to claim 2, characterized in that: The corrugated directions of the outer corrugated core layer (4) and the inner corrugated core layer (2) are perpendicular to each other.

4. The moisture-proof composite corrugated cardboard according to claim 3, characterized in that: The moisture-proof composite corrugated cardboard has a hot melt butyl adhesive sealing layer (6) at the cut edge, and the width of the hot melt butyl adhesive sealing layer (6) is 5-8mm.

5. The moisture-proof composite corrugated cardboard according to claim 4, characterized in that: The hot melt butyl sealant layer (6) is further covered with a PE heat shrink film (7), the thickness of which is 20 μm.

6. The moisture-proof composite corrugated cardboard according to claim 5, characterized in that: The surface moisture-proof layer (5) is provided with an acrylic waterproof coating layer (8) on the outside of the PE membrane, and the thickness of the acrylic waterproof coating layer (8) is 5-10μm.

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