How To Distinguish Aluminum Foil From Good Or Bad

- Oct 28, 2019-

In the production process of aluminum foil, it is necessary to go through rolling, finishing, annealing, packaging and other processes, and the interlocking production process, any problem in one link may lead to the quality problem of aluminum foil. The quality defects of the purchased aluminum foil products not only affect the appearance, but also directly affect the quality of the produced products, and even more directly lead to the aluminum foil breaking and shutdown, which greatly affects the production efficiency. So how do you tell the difference between aluminum foil?

According to the experience of the aluminum industry, the quality of the aluminum foil can be directly detected by your "eyes". However, to distinguish the quality of aluminum foil, we should first understand the common defects of aluminum foil quality, only the number of hearts, and then check the quality of common aluminum foil one by one, in order to prevent the quality of defective aluminum foil into the warehouse.

Today, we have sorted out some common aluminum foil quality defects. When we buy the aluminum foil, we only need to diagnose the aluminum foil for the problem. The quality is good or bad.

1. Aluminum foil bump

▲Aluminum foil bump refers to the damage caused by the foil on the surface or end face after collision with other objects during handling or storage. Most of the bruises are caused by inadvertent attention when packaging aluminum foil.

2. Corrosion

▲The surface of the aluminum foil is in contact with the surrounding medium. After a chemical reaction or electrochemical reaction, the surface of the aluminum foil will be tarnished on the surface of the aluminum foil. In severe cases, gray corrosion products will be produced. The corroded aluminum foil has a great influence on the aesthetics of the products produced at the terminal.

3. Surface bubbles

▲Aluminum foil with surface bubble defects, the surface of the foil will have irregular circular or strip-shaped cavity protrusions; the edges of the protrusions are smooth, the two sides are asymmetrical, the distribution is irregular, and the surface bubbles cause the points of the aluminum foil to be affected. Unbalanced forces are likely to cause a break.

4. Dark stripes

▲The dark surface stripe mostly appears on the double-joint product. The dark surface has obvious bright and dark strip patterns along the rolling direction, which affects the appearance.

5. Imprint

▲ There are many conditions that may cause impression on the surface of the aluminum foil, such as defects in the surface of the roll or guide roll or dirt such as metal chips, the surface of the sleeve or the die is not clean or there are smooth protrusions locally, or the foil is taken up. The surface is stuck with foreign matter and so on. The surface of the foil on which the impression appears is generally free of individual or periodic depressions or projections that are easily discernible.

6. Oil spots

▲ Common aluminum foil oil stains are formed after annealing, generally pale yellow, brown, yellowish brown spots.

7. Degreasing is not clean

▲Check whether the degreasing is clean. Generally, after annealing, the degreasing grade is detected by brushing water. If the level specified by the brushing test is not reached, the aluminum foil may have oil.

8. Cracked edge

▲The phenomenon that the longitudinal edge of the aluminum foil surface is broken, called the split edge. In severe cases, obvious gaps can be seen at the edges.

9. Poor plate type

▲Because of uneven deformation, the surface of the foil is locally undulating, which is called poor plate shape. According to the location of the defect, it is divided into intermediate waves, side waves, two-ribbed waves and composite waves. In the side, the edge wave is called (pictured), and the middle wave is called in the middle. The two are called composite waves, neither in the middle nor in the side.

10. Adhesion

▲The aluminum foil roll is not easy to open, and the multiple sheets are plate-shaped when opened. The free fall length of the product cannot meet the standard requirements. In severe cases, the single sheet cannot be opened, and the adhesion of aluminum foil will seriously affect the production of the product.