Abstract: Vacuum aluminum-plated paper is a green environment-friendly printing and packaging material. This article expounds the production process, influencing factors and applications of vacuum aluminum-plated paper from the perspective of environmental protection and green packaging, and evaluates its degradation performance.

Keywords: vacuum aluminized paper; green packaging; production process; influencing factors; degradation performance

Green packaging refers to packaging that is harmless to the ecological environment and human health, can be recycled or reused, and can promote sustainable development. Developed countries in the world have already determined that packaging should meet the “4R+1D” principle, namely low consumption, development of new green materials, reuse, recycling and degradability. It is under the guidance of this environmental protection concept that vacuum aluminum-plated paper has applied the development requirements of the contemporary printing and packaging industry. Vacuum aluminum-plated paper, also known as spray paper, is a new type of green packaging material widely used in packaging industry in the world since the 1980s. Because of its noble and beautiful metal texture, relatively low material cost, good packaging flexibility, stable and reliable printing performance, and biodegradable, recyclable environmental performance, it is increasingly favored by the printing and packaging industry. The range of applications is also growing.

At present, vacuum aluminum-plated paper is mainly used in the following aspects:

(1) Vacuum aluminized beer label paper.
(2) Vacuum aluminum-plated cigarette lining paper.
(3) vacuum aluminum plated paper jam.
(4) vacuum aluminum food packaging paper.

Vacuum aluminum-plated paper is a reusable, degradable packaging material that has recently emerged for aluminum foil composite paperboard and PET peritoneal paperboard paper. Aluminum foil composite paper is a kind of composite paperboard formed by compounding aluminum foil with paperboard. It has the disadvantages of high production cost and non-environmental protection, and is gradually replaced by vacuum aluminum plating paper. From the perspective of protecting the environment and promoting green packaging, this article elaborates on the production raw materials, production processes and applications of green aluminum-coated paper for environmentally friendly materials, and evaluates its degradation performance.

1 Production of Vacuum Aluminized Paper

1.1 Production Process of Vacuum Aluminized Paper

Vacuum aluminum-plated paper according to the production process can be divided into direct (aluminum paper surface) and transfer method (film surface spray aluminum) two. The direct method is a method in which the raw paper is directly placed into a vacuum aluminum-plating machine to perform aluminum spraying after the surface treatment, and the process flow is shown in FIG. 1 . This method is limited to spray aluminum on tissue paper.

Figure 1 Direct process vacuum aluminum coating paper production process and transfer method Alumina is PET, BOPP and other films for the transfer of the substrate, the coating coloring, aluminum spray, composite, peeling and other processing, so that the metal with a shiny aluminum The method by which the molecular layer is transferred to the surface of paper or paperboard by gluing. Its technological process is shown as in Fig. 2: Fig. 2 transfer method vacuum aluminizing production technological process This method can produce 40-450g/m paper or cardboard. Compared with the direct method, the outstanding features of the transfer method: (1) can produce any thickness of paper or cardboard. (2) The flatness of the PET film can be fully utilized to make the paper metallic luster brighter. (3) Laser anti-counterfeit vacuum aluminized paper or cardboard that can produce radiant random patterns and characters. The disadvantage of the transfer method compared to the direct method is that the used PET film is transferred many times, and disposal after disposal is also a problem.

1.2 Properties and Influencing Factors of Vacuum Aluminized Paper

The raw and auxiliary materials produced by vacuum aluminum-plating paper are non-toxic and odorless, meet the requirements of food hygiene (in line with the US FDA certification), and have a wide range of applications. It is widely used for exquisite packaging of cigarettes, alcohol, food, tea, medicine and crafts. After some special processing, it can also be used for construction and decoration materials.

Vacuum aluminized paper has good gloss and high smoothness, and its metal texture is brighter than that of aluminum. In particular, the transfer method of aluminum-plated paper, bright color, beautiful appearance, strong visual sense. At the same time he also has excellent barrier properties, moisture, oxidation resistance as much as aluminum-coated paper performance. The biggest feature of vacuum aluminum-plated paper is that its printing performance and mechanical processing performance are superior to those of aluminum-covered paper and laminated paperboard, and ink will not burst. It is suitable for gravure printing, offset printing, flexo printing and screen printing, and can also be directly embossed, die cut, embossing and other processes. In the production of vacuum aluminized paper, the performance of the base paper is critical and it will affect the quality of vacuum aluminized paper. For the printing and packaging industry, especially the tobacco packaging industry, the performance of paper is mainly divided into the following four categories:

1) Basic properties: thickness, weight, density, moisture uniformity;

2) Appearance data: whiteness, hue, glossiness, smoothness, printability, ink absorption uniformity;

3) Intensity data: stiffness, internal bond force, z-direction tension, MIT folding resistance, tensile strength;

4) Operational data: moldability, gluing, bending, printing and packaging operation performance; aluminum-plated cigarettes as a high-grade packaging material, have high requirements for the smoothness of the bottom paper. At the same time, since aluminum foil peels off to the surface of the paper, it will refract the texture of the surface of the paper. Therefore, this process also emphasizes that the surface texture of the material of the bottom paper is smooth and delicate. Only when it is evenly coated can an ideal surface effect be achieved. In addition, the uniformity of the thickness of the paper and the uniformity of the moisture control are important. Uniform thickness is critical for printing processes and tobacco packaging, especially for high-speed packaging equipment. Uniform thickness can greatly improve printing quality, speed, and efficiency of cigarette packers. The even control of moisture can effectively improve the molding pressure, die-cutting quality, reduce color cracking, improve stability and reduce curling. Due to the moisture absorption, the aluminum plating process is more likely to cause curl than the normal printing process, which affects the packaging yield and quality, so it is important to strictly control the moisture content of the paper.

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