What is the cause of oil spots on aluminum foil?

The rolling oil and other oil stains remaining on the surface of the foil, which are formed on the foil surface to varying degrees after annealing, are called oil spots.

The main reasons for oil spots: high degree of oil in aluminum foil rolling, or inappropriate distillation range of rolling oil; mechanical oil infiltration in aluminum foil rolling oil; improper annealing process; excessive oil on the surface of the product during rolling; The slitting tension is too large, causing the aluminum foil roll to be too tight.