The mechanical properties of aluminum foil mainly include tensile strength, elongation, crack resistance, etc. The mechanical properties of aluminum foils are mainly determined by the thickness. The national standard GB / t3189-2003 aluminum and aluminum alloy foils stipulates the longitudinal mechanical properties of aluminum foils in China.
Generally speaking, aluminum foil is light in weight, good in ductility, thin in thickness and small in mass per unit area. But the strength is low, easy to tear, easy to break when folding, and produce holes, so it is generally not used for packaging products alone. In many cases, composite with other plastic film and paper to overcome its shortcomings.
2. Aluminum foil have high barrier
Aluminum foil has a high barrier to water, steam, light and fragrance, and is not affected by the environment and temperature. Therefore, it is often used in fragrance packaging, moisture-proof packaging, etc., to prevent the moisture absorption, oxidation and volatile deterioration of the packaging content. It is especially suitable for high temperature cooking and sterilization packaging of food.
3. Aluminum foil have corrosion resistance
The oxidation film is formed on the surface of aluminum foil naturally, and the formation of oxidation film can further prevent the oxidation from continuing. Therefore, when the package content has high acidity or alkalinity, it is often coated with protective coating or PE coating on its surface to improve its corrosion resistance.
4. Aluminum foil have heat and low temperature resistance
The aluminum foil is stable at high and low temperature. It does not shrink at - 73 ~ 371 ℃, and has good thermal conductivity. Its thermal conductivity can reach 55%. Therefore, it can be used not only for high temperature cooking or other hot processing, but also for frozen packaging.
5. Aluminum foil have blackout
Aluminum foil has a good blackout, its reflective rate can be as high as 95%, at the same time, its appearance is silver white metallic luster, through the surface printing decoration can show a good packaging effect, so aluminum foil is also a high-grade packaging material.
