How to Prevent Pinholes in Aluminum Foils

The application fields and demand of aluminum foil packaging material both has rapid development, especially the light gauge foil. In addition to electrolytic capacitors, more than 90% of the aluminum foil for packaging is light gauge foil.

The irregular small holes visible on the surface of the aluminum foil are called pinholes. As the thickness decreases, the number of pinholes increases, which is one of the main defects of aluminum foils. When the thickness is above 0.02mm, the aluminum foil can be completely pinhole-free.

It is the existence of pinholes that makes the oxygen transmission rate and water vapor transmission rate of aluminum foil not zero. The size and number of aluminum foil pinholes have a decisive influence on the moisture resistance, gas barrier properties and light-shielding properties of aluminum foil and its composite materials.

Dust in the blank, on the roll, in the rolling oil, or even in the air that reaches a size of about 6μm into the roll gap will cause pinholes. How to prevent pinholes in aluminum foils?

With the improvement of the installed level of aluminum foil equipment, the aluminum foil rolling conditions have been improved, especially the effective filtration of dust and rolling oil and the quick setting of roll changing system. It is now more related to the metallurgical quality and processing defects of the blank.

It is generally believed that pinholes are mainly related to gas content, inclusions, and compounds and component segregation of the blanks. Adopting effective aluminum liquid purification, filtration, grain refinement, etc. all help reduce pinholes. The use of alloying and other means to improve the hardening property of the material also helps to reduce pinholes.

The rollers replacement and dust-proof measures are all necessary conditions to reduce pinholes in aluminum foil. Rolling with small tension will also help reduce pinholes. We also need to strengthen the filtration of rolling oil.

The pinholes of 6μm aluminum foil rolled by high-quality aluminum blanks can be less than 100/m². With advanced rolling technology, the common specifications of HaomeI foil packaging material is free of pinholes. Welcome to leave message below to get the latest price.