How to Distinguish Aluminum Foil is Good or Bad

In the production process of aluminum foil, it needs to go through many processes such as rolling, finishing, annealing, and packaging, and interlocking production processes. Any problems in any link may lead to aluminum foil quality problems. The quality defects of the refinished aluminum foil products will not only affect the appearance, but also directly affect the quality of the products produced. Furthermore, it will directly cause the aluminum foil to pull off and stop and greatly affect the production efficiency. How to distinguish the quality of aluminum foil?
According to the experience of aluminum industry people, the quality of aluminum foil can be detected directly with your “eyes”. However, to distinguish the quality of aluminum foil, we must first understand what the common aluminum foil quality defects are, only the heart has a few, and then check the common quality problems of aluminum foil one by one, in order to prevent the aluminum foil with quality defects into the library.
1. Aluminum foil bruises
Aluminum foil bumping refers to damage to the surface or end surface of a foil after it collides with other objects during handling or storage. Most of the bumps were caused by inadvertent packing of aluminum foil.
2. Corrosion
The surface of aluminum foil is in contact with the surrounding medium. After a chemical reaction or electrochemical reaction occurs, defects on the surface of the aluminum foil will cause the surface of the etched aluminum foil to lose its luster. In severe cases, gray corrosion products will also be produced. The corroded aluminum foil has a great influence on the aesthetic appearance of the product produced by the terminal.
3. Surface bubbles
Aluminum foil with surface bubble defects will have irregular circular or strip-shaped cavity protrusions on the surface of the foil; the edges of the protrusions are rounded, the two sides are asymmetric, the distribution is irregular, and the surface bubbles cause the aluminum foil to receive various points. Unbalanced forces are likely to cause breaks in downtime.
4. Dark side stripes
Dark-faced stripes are mostly present on double-products. The dark side has a distinctive pattern of light and dark stripes along the rolling direction, affecting the appearance.
5. Imprint
There are many situations that can cause marks on the surface of aluminum foil, such as defects in the surface of the roller or guide roller, or dirt such as metal chips. The surface of the sleeve or die is not clean or there are smooth protrusions locally, or the foil is taken up when wound. The surface has foreign matter, etc. The surface of the foil where the mark is present will generally have a single or periodic depression or bulge that is easily discernible.
6. Oil spots
Common aluminum foil oils are formed after annealing and are generally light yellow, brown, and yellow-brown.
7. Degreasing
Detection for degreasing is usually done after the annealing. The level of degreasing is determined by the brushing method. If the level specified in the brushing test is not reached, there may be oil on the aluminum foil.
8. Cracked edges
Fracture of the longitudinal edge of the surface of the aluminum foil, known as edge cracking. Severe visible gaps in the edges.
9. Bad plate type
Due to uneven deformation, the surface of the foil material is locally uneven, which is called poor plate type. According to the site of the defect, it is divided into middle wave, edge wave, two-rib wave and composite wave. In the edge, it is called the edge wave (pictured), and in the middle is the intermediate wave. Both are called composite waves, neither in the middle nor in the edges.
10. Adhesion
Aluminum foil leaflets are not easy to open, and when multiple sheets are opened, they are spliced. The length of the product does not meet the standard requirements. In severe cases, leaflets cannot be opened, and aluminum foil adhesion can seriously affect product production.
11. Hole
The surface of the foil is prone to holes.
12. Loose rolls
Since the take-up is not tight during slitting, when the foil material is taken upright in the direction of the die, the foil is displaced from layer to layer; when the foil is pressed with a finger, partial depression may occur.
13. Burrs
After shearing, there are different sized spikes on the edge of the foil.
14. The wrong layer
Irregular movement between the aluminum foil roll end surface layer and layer, resulting in uneven end surface.