What material is the silver layer for inserting straws?

Aluminum foil! A hot stamping material made of aluminum directly rolled into thin sheets, its hot stamping effect is similar to that of pure silver foil, so it is also called fake silver foil. Because aluminum foil is soft, malleable and silvery, it can be printed if the calendered sheet is mounted on offset paper with sodium silicate and other substances. However, aluminum foil itself is easy to oxidize, the color becomes darker, and it will fade when touched by friction, which is not suitable for long-term preservation of book covers. Because of its excellent characteristics, aluminum foil is widely used as packaging materials for food, beverage, cigarettes, medicines, photographic substrates, household items and so on. Electrolytic capacitor materials; Thermal insulation materials for buildings, vehicles, ships and houses; It can also be used as decorative gold and silver thread, wallpaper and decorative trademark of various stationery, printed matter and light industrial products. Among the above uses, aluminum foil is the most effective packaging material. Aluminum foil is a kind of soft metal film, which is not only moisture-proof, airtight, light-proof, wear-resistant, fragrant, non-toxic and tasteless, but also easy to process exquisite patterns and patterns of various colors because of its elegant silver luster, so it is more easily favored by people. Especially after aluminum foil is compounded with plastic and paper, the shielding performance of aluminum foil is integrated with the strength of paper and the heat sealing performance of plastic, which further improves the shielding performance of aluminum foil against water vapor, air, ultraviolet rays and bacteria and greatly broadens the application market of aluminum foil. Because the packaged goods are completely isolated from external light, humidity and gas, the packaging materials are well protected. Especially for the packaging of cooked food, the use of this composite foil material can at least ensure that food will not go bad for more than one year. Moreover, heating and unpacking are very convenient, which is very popular with consumers. With the improvement of people's living standards and the development of tourism, the demand for beer, soda and other beverages and canned food is increasing day by day, which requires modern packaging and decoration to facilitate competition in the international market. In recent years, in order to meet the market demand, people have developed packaging materials such as plastic film and spray foil with good shielding performance, but their comprehensive performance is not as good as that of film covering and laminating. Therefore, it can be said that aluminum foil is a perfect packaging material with many excellent properties, which fully shows its broad application prospects in many fields. In order to improve the rolling efficiency and the quality of aluminum foil products, modern aluminum foil rolling mills are developing in four directions: large coil, wide width, high speed and automation. The roll width of contemporary aluminum foil rolling mills has reached more than 2200mm, the rolling speed has reached more than 2000m/min, and the coil weight has reached more than 20 t. The automation level of the corresponding rolling mills has also been greatly improved, and the thickness control system (AGC) is generally installed, and most of them are equipped with flatness meters (AFC). The aluminum foil industry is facing a period of rapid development.