As we know that aerosol can includes external printing and internal coating, which are both of great significance to your products. But what are the functions of the internal coating? Let's go through this article to know about more.

1. Importance of internal coating: The main function of the internal coating of aluminum cans is to protect the internal surfaces from corrosion by aggressive chemicals contained in the filler. Besides, the internal coating also prevents direct contact between the filling and metal, thus extending the shelf life and ensuring the safety of the product.

2. Selection of internal coating materials: Materials of the internal coating is essential to ensure the safety and durability of aerosol cans. Commonly it includes epoxy, organic solvents, polyphthalamide phthalimide. And each of which has different advantages and limitation. For example, epoxy has good processability and chemical resistance while polyphthalamide phthalimide has particularly excellent chemical resistance.

3. Production process: The production process for aluminum aerosol cans consists of a number of steps, including the manufacture of the can body, the application of the internal coating, drying, and quality testing. The internal coating technology is the key link which usually uses an airless pump nozzle system to spray the coating onto the inner surface of the rotating can body, then goes to drying and curing.

4. Testing: The internal coating of aerosol cans is subjected to a series of performance tests to ensure its quality and safety. It includes appearance quality, dimensions, weld filler integrity, internal and external coating adhesion, external coating hardness, airtightness performance, deformation pressure and burst pressure testing.
5.  Market and technology trends: As the market develops and technology advances, the interior coating technologies of aerosol can are constantly developing. For example, water-based modified epoxy resin coatings are favored for their environmental performance. At the same time, market demands for lightweight and high-performance aerosol cans is also driving the development of related technologies.

All in all, ensuring the quality of the internal coatings can help improve the shelf life and safety of the aerosol cans. In MIJIA, various internal coatings are available for your aeroosl products. Tell us what you need, we do for you!