Views: 0 Author: Site Editor Publish Time: 2022-09-19 Origin: Site
3. Aluminized paper can be divided into direct evaporation method and transfer method according to its production process: direct method is the method of directly placing the paper in a vacuum aluminizing machine for aluminizing; The transfer method is to aluminize the BOPP or PET film coated with a release agent and a protective layer, compound it with paper, peel off the base film, and transfer the aluminum layer to the surface of paperboard through adhesive action. Compared with the two methods, the direct plating method is suitable for producing aluminized paper with lower gram weight (50g / m2), and the transfer method is suitable for producing aluminized paper with higher gram weight (100g / m2). The production process flow chart of aluminized paper is as follows:
4. Non metallic coating
Since the 1990s, the rapid development of microwave heating technology has put forward new requirements for microwave food packaging and the packaging of a class of commodities that need to be sterilized by microwave, that is, packaging materials should not only have excellent barrier performance, but also have high temperature resistance, microwave permeability and other characteristics. It is difficult for traditional packaging materials to fully possess these characteristics. Therefore, in recent years, Japan, Germany, the United Kingdom, Italy, Canada, the United States and other industrial developed countries have invested a lot of manpower and material resources in the research and development of new high barrier packaging materials - SiOx and other metal oxide coated composite packaging materials. In addition to the barrier performance comparable to that of aluminum-plastic composite materials, this kind of materials also have the advantages of good microwave permeability, high temperature resistance, transparency, and small impact of ambient temperature and humidity. Especially in terms of fragrance preservation, the effect is the same as that of glass bottle packaging. After long-term storage or high-temperature treatment, it will not produce peculiar smell. Therefore, it is also called transparent coating. It can be widely used in the packaging of food, drugs, cosmetics, medical devices and other commodities with high packaging safety and health performance requirements and long shelf life; It is especially suitable as a kind of commodity packaging material for the application of microwave heating technology.
The non-metallic coating can be vapor deposited using Si, SiOx, SiO2 or other oxides, or other oxides such as Al2O3, MgO, Y2O3, TiO2, Gd2O3, etc., of which SiOx and Al2O3 are the most commonly used. There are two kinds of evaporation sources for oxide coating: resistance evaporation source and electron beam evaporation source. The resistance evaporation source heats the evaporation raw materials by the principle of resistance heating, and the maximum heating temperature can reach 1700 ℃. The electron beam evaporation source evaporates the raw material by accelerating the collision of electrons. The evaporation source is equipped with an electron gun. The electron beam is accelerated and concentrated by a magnetic field or an electric field to concentrate the electron beam on the local position of the evaporated material to form a heating beam spot. The beam spot temperature can reach 3000 ~ 6000 ℃, and the energy density can reach up to 20kW / cm2.