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Possible quality defects of aluminum foil

Possible quality defects of aluminum foil

  • Release date:2019-12-20
  • Summary:1. Aluminum foil injury ▲ Aluminum foil bump refers to the damage to the surface or end surface of the foil after it collides with other objects during transpo
    1. Aluminum foil injury
     
    ▲ 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 or electrochemical reaction occurs, the defects on the surface of the aluminum foil will lose its luster and the gray corrosion products will be produced in severe cases. The corroded aluminum foil will greatly affect the aesthetics of the products produced by the terminal. Zh
     
    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. The surface bubbles cause the aluminum foil strip to be affected at various points. Unbalanced force is likely to cause breakage and shutdown. Zh
     
    4.Dark side stripes
     
    ▲ Most of the dark side stripes appear on the double product. The dark side has obvious light and dark stripe patterns along the rolling direction, which affects the appearance. Zh
     
    5.Seal
     
    ▲ There are a variety of situations that can cause imprints on the surface of aluminum foil, such as defects on the surface of the roller 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 locally, or the foil material is rolled up 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. Zh
     
    6. Oil spots
     
    ▲ The common aluminum foil oil stains are formed after annealing, and generally have pale yellow, brown, and tan marks. Zh
     
    7. Degreasing is not clean
     
    ▲ Check whether the degreasing is clean. Generally, after annealing, the degreasing level is tested by brushing method. If it does not reach the level specified in the brushing test, there may be oil on the aluminum foil. Zh
     
    8. Split edge
     
    ▲ The phenomenon that the longitudinal edge of the aluminum foil surface is cracked is called cracked edge. Significant gaps can be seen on the sides in severe cases. Zh
     
    9. bad shape
     
    ▲ Due to uneven deformation, the phenomenon of unevenness on the surface of the foil material is called flatness. 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 the two are called the compound wave, which is neither the middle nor the side is called the two rib wave. Zh
     
    10. Adhesion
     
    ▲ Aluminum foil rolls are not easy to open. When multiple sheets are opened, they will become slab-shaped, and the free-fall length of the product cannot meet the standard requirements. Zh
     
    11. Holes
     
    ▲ The surface of the foil is prone to holes. Zh
     
    12.Matsumaki
     
    ▲ 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 finger, the phenomenon of local depression can occur. Zh
     
    13.Glitch
     
    ▲ After cutting, there are thorns of different sizes on the edge of the foil. Zh
     
    14. Staggered
     
    ▲ The irregular movement between the end layer and the layer of the aluminum foil coil causes the end surface to be uneven. Zh
     
    15. Tower shape
     
    ▲ 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. Zh
     
    16.Edge
     
    ▲ The phenomenon that the two ends or one end of the aluminum foil rolls up is called warped edge, which is characterized by the aluminum foil rolled edge rising upwards. You can touch it with your hands, and it will have obvious unevenness. Zh
     
     17.Pinhole
     
    ▲ The irregular small holes on the surface of the aluminum foil are visible under the light. For the production of aluminum foil packaging materials, the problem of pinholes will affect the sealing. Zh
     
    18. End face pattern
     
    ▲ Looking at the end of the aluminum foil partly or entirely, the core has a radial pattern along the wall thickness; there is a slight wave at the edge of the aluminum foil after unrolling. Zh
     
    19. White bars
     
    ▲ White stripes on the surface of aluminum foil along the 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 is thinned, the stripes tend to increase significantly. Zh
     
    20. Wrinkles
     
    ▲ Small, longitudinal or oblique partial convexity, one or several smooth grooves on the surface of aluminum foil. Zh
     
    21. Wrinkling
     
    ▲ The surface of the aluminum foil roll cannot be flattened longitudinally or horizontally. Zh
     
    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. Zh
     
    23. Arrow (Bird's Nest)
     
    ▲ A certain number of protrusions on the end surface of the aluminum foil coil are at the same place from the inside to the outside, and the degree of protrusion gradually decreases from the inside to the outside or from the outside to the inside. Zh
     
    24.Black line
     
    ▲ The dark continuous lines on the surface of the aluminum foil have obvious color differences between other parts. Zh
     
    25.Bright line
     
    ▲ Similar to the dark line, the bright line is a vertical continuous bright strip on the surface of the aluminum foil, which has obvious color difference between the generated part and other parts. Zh
     
    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 aluminum foil. Zh
     
    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 aluminum foil. Zh
     
    28.Stripes
     
    ▲ The aluminum foil surface has regular thin stripes on the surface, which are generally white and have no unevenness. Sometimes it is part of the coil, and sometimes it covers the entire surface, which also affects the appearance. Zh
     
    .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. Zh
     
    30. Airway
     
    ▲ Due to the high hydrogen content in the melt, the strips of the aluminum foil in the rolling direction that appear during the rolling process are crushed and have a certain width. Zh
     
    31. Abrasions
     
    ▲ Bunches (or groups) of scars caused by relative sliding on the foil surface due to the relative sliding between the edges and the surface of the material or the surface to surface contact. Zh
     
    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. Zh
     
    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 seen more clearly. Zh
     
    34.Slit
     
    ▲ After rolling, the aluminum foil naturally cracks in the longitudinal direction. Zh
     
    35. Roller Eye
     

    ▲ Small holes with rolling traces appearing on the surface of the aluminum foil, some of which are mesh-shaped, and their sizes are generally larger than pinholes. 

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