How to distinguish the quality of aluminum foil?

- Mar 06, 2020-

How to distinguish the quality of aluminum foil?

In the production process of aluminum foil, rolling, finishing, annealing, packaging and other multiple processes are involved. The interlocking production process, any problem in any link may cause aluminum foil quality problems. The quality defects of the purchased aluminum foil products will not only affect the appearance, but also directly affect the quality of the products produced, and even directly cause the aluminum foil to break and stop, which will greatly affect the production efficiency. So how to distinguish the quality of aluminum foil?

According to the experience of aluminum industry people, distinguishing the quality of aluminum foil can be directly detected by your "smart eyes". However, in order to distinguish the quality of aluminum foil, we should first understand the common quality defects of aluminum foil. Only by knowing the quality of the aluminum foil, and then checking the common aluminum foil quality problems one by one, can we prevent the storage of aluminum foil with quality defects.

Today, we have sorted out the more complete aluminum foil quality defect problems in history, After we bought the aluminum foil, we only need to diagnose the problem for this batch of aluminum foil. You can figure it out!

Aluminium foil 8011

1. Foil bump

▲ Aluminum foil bump refers to the damage to the surface or end surface of the foil after it collides with other objects during transportation or storage. Most of the injuries are caused by the carelessness of aluminum foil packaging.

2. corrosion

▲ The surface of the aluminum foil is in contact with the surrounding medium. After the chemical reaction or electrochemical reaction occurs, the defects on the aluminum foil surface will lose the luster of the corroded aluminum foil surface, and gray corrosion products will be produced in severe cases. The corroded aluminum foil will have a great impact on the aesthetics of the product produced by the terminal.

3. Surface bubbles

▲ Aluminum foil with surface bubble defects will have irregular round or strip-shaped cavity protrusions on the surface of the foil; the edges of the protrusions are smooth, the two sides are asymmetric, and the distribution is irregular. Unbalanced force is likely to cause breakage and shutdown.

4.Dark side stripes

▲ Most of the dark side stripes appear on double products. The dark side has obvious light and dark stripe patterns along the rolling direction, which affects the appearance.

5. Imprint

▲ There are a variety of conditions that can cause imprints on the surface of aluminum foil, such as defects on the surface of the roll or guide roller or dirt such as metal shavings, the surface of the sleeve or the core is not clean or there are smooth protrusions, or the foil is rolled Foreign matter is stuck on the surface. Single or periodic depressions or protrusions generally exist on the surface of the foil where the imprints appear, which is easy to identify.

6. Oil spots

▲ Common aluminum foil oil stains are formed after annealing, and generally have pale yellow, brown, and tan marks.

7. Degreasing is not clean

▲ Check whether the degreasing is clean. Generally, after annealing, the degreasing level is detected by brushing method. If it does not reach the level specified in the brushing test, the aluminum foil may carry oil.

8. Cracked edges

▲ The phenomenon that the longitudinal edge of the aluminum foil surface is cracked is called cracked edge. When severe, obvious gaps can be seen on the sides.

9. Bad shape

▲ Due to uneven deformation, the surface of the foil is uneven, which is called bad plate shape. According to the location of the defect, it is divided into intermediate waves, side waves, two rib waves, and compound waves. The side wave is called the edge wave (pictured), the middle wave is called the middle wave, and both of them are called the compound wave, which is neither the middle nor the side is called the two rib wave.

10. Adhesion

▲ Aluminum foil rolls are not easy to open. When multiple sheets are opened, they are slab-like. The free-fall length of the product cannot meet the standard requirements. In severe cases, the single sheets cannot be opened.

11. Hole

▲ The surface of the foil is prone to holes.

12. Loose roll

▲ Because the winding is not tight during slitting, when the foil is held in the direction of the die, the foil will shift between layers. When the foil is pressed with your fingers, the phenomenon of local depression can occur.

13. glitches

▲ After cutting, there are thorns of different sizes on the sides of the foil.

14. Staggered

▲ The irregular movement between the end layer and the layer of the aluminum foil coil causes the end surface to be uneven.

15. Tower

▲ The displacement between the aluminum foil end layer and the layer causes a tower-like offset, which is called a tower shape. A tower is a special case of a split floor, and the side looks like a spire.

16.Warping

▲ The phenomenon that the two ends or one end of the aluminum foil rolls upwards is called warping. It is characterized by the aluminum foil curls rising upwards. You can touch it with your hands, and it will have obvious unevenness.

17.pinhole

▲ The irregular small holes on the aluminum foil surface are visible under the light. For the production of aluminum foil packaging materials, the problem of pinholes will affect the sealing.

18.End face pattern

▲ Looking at the end of the aluminum foil partly or whole, the core has a radial pattern along the wall thickness; there is a slight wave at the edge of the aluminum foil after unwinding.

19. White bars

▲ White stripes on the surface of aluminum foil along rolling direction, width or interval. Generally corresponding to the lower surface of the cast and rolled strip, the stripes are mostly concentrated in the middle and two rib positions of the aluminum foil. As the rolling of the aluminum foil becomes thinner, the stripes tend to increase significantly.

20. Wrinkles

▲ Small, longitudinal or oblique partial raised surface of aluminum foil surface, one or several smooth grooves.

21. Wrinkling

▲ The surface of the aluminum foil roll cannot be flattened longitudinally or horizontally.

22. Highlights

▲ When the aluminum foil is double-rolled, uneven and shiny spots on the dark surface of the aluminum foil appear as bright spots.

23. Arrow (Bird's Nest)

▲ A certain number of protrusions on the end surface of the aluminum foil roll are at the same place from the inside to the outside, and the degree of the protrusion gradually decreases from the inside to the outside or from the outside to the inside.

24. Black Line

▲ The dark continuous lines on the surface of the aluminum foil have obvious color differences between other parts.

25. bright line

▲ Similar to the dark line, the bright line is a longitudinal continuous bright strip on the surface of the aluminum foil, and the color difference between the generated part and other parts is obvious.

26. Drumming

▲ The surface of the aluminum foil is strip-shaped protrusions in the longitudinal direction, and there are obvious convex and concave feelings on the hand. Sometimes it disappears after removing the outer aluminum foil, and sometimes it runs through the entire roll of aluminum foil.

27. Dark side chromatic aberration

▲ The surface of the aluminum foil is strip-shaped protrusions in the longitudinal direction, and there are obvious convex and concave feelings on the hand. Sometimes it disappears after removing the outer aluminum foil, and sometimes it runs through the entire roll of aluminum foil.

28. horizontal stripes

▲ Aluminum foil surface has regular thin stripes on the surface, which is generally white and has no unevenness. Sometimes it is part of the coil, and sometimes it covers the entire surface, which also affects the appearance.

29.Herringbone pattern

▲ The regular chevron pattern on the surface of the foil is generally white, and the surface has obvious color difference, but it is very smooth.

30. Airway

▲ Because of the high hydrogen content in the melt, the strips along the rolling direction that appear in the aluminum foil during the rolling process are crushed and have a certain width.

31. Abrasions

▲ Because of the relative sliding between the edges and the surface between the materials, or the surface-to-surface contact, the bundles (or groups) of the wounds are caused by the relative sliding.

32. Scratches

▲ intermittent or continuous groove-like scars on the surface of the foil. Generally produced when a sharp object slides relative to the surface of the foil.

33. Non-Metal Pressing

▲ Non-metallic inclusions are pressed into the surface of the foil, and the surface has obvious dot-like or strip-shaped yellow-black defects, which can be clearly seen.

34. Slit

▲ After rolling, the aluminum foil naturally cracks in the longitudinal direction.

35.Roller

▲ The small holes appearing on the surface of the aluminum foil periodically with rolling marks, and some of them are mesh-shaped, and the size is generally larger than the pinhole.