1. The application fields of aluminum foil are extremely wide
Aluminum foil is made of electrolytic aluminum with a purity of more than 99.5% and rolled. It has a shiny metallic luster, non-toxic, tasteless, odorless, excellent shading, and a reflective rate of up to 95%. It is stable at high and low temperatures, does not expand or shrink at a temperature of 73 to 371°C, has good barrier properties, is moisture-proof and air-tight, maintains fragrance, moisture, and oxygen. It is an excellent middle-layer substrate film for high-end retort packaging.
Aluminum foil is mostly used for high-end packaging and blister packaging of medicines, moisture-proof and fragrant paper for cigarettes, high-end packaging for chocolates, leak-proof packaging for daily chemical products, sealing film for instant noodle bowls, sealing labels for beer and champagne, milk and milk Composite packaging of products and juices, etc.
2. Aluminum foil is rarely used alone
Aluminum foil is widely used in flexible packaging. Due to its low strength, it is easy to break at the beginning of folding. So it is rarely used alone.
Generally, it is made of composite packaging materials with paper, cellophane, and polyethylene film. When laminating, glue bonding, dry lamination, extrusion lamination, casting lamination, etc. are used according to different types of adhesives to make up for its easy cracking and lack of Disadvantages such as softness, no thermal adhesive, etc. When aluminum foil is combined with other materials, the airtightness and moisture resistance of other materials should be considered. The composite of aluminum foil and polyester film can greatly improve the folding resistance.
3. The thickness of aluminum foil should be considered in composite use
The thickness of aluminum foil used in composite materials is 0.007~0.009mm, which is also relatively economical. At present, the thinner aluminum foil has 500 to 600 holes per square meter, which can only be moisture-proof if the necessary strength is ignored. If its thickness is above 20 μm, it can meet the requirement of no holes and moisture resistance.
In actual use, in addition to packaging food and medicine, the thickness selection should be based on different contents, especially for products sold in the domestic market, and consumers' affordability should be considered.