Heat sealing aluminum foil is mostly used for dairy products such as fresh milk and yogurt, and the sealing aluminum foil is usually 1235 and 8011 aluminum foil. Heat sealing performance is the most important performance of aluminum foil for bottle.
Generally speaking, there are several important factors affecting aluminum foil’s heat sealing performance. Heat-sealing temperature, heat-sealing strength and heat-sealing layer thickness are interrelated. The heat-sealing temperature affects the heat-sealing strength, and the heat-sealing film thickness in the heat-sealing layer plays an important role in the heat-sealing effect.
8011 alloy aluminum foil is mostly used for the packaging of dairy products such as fresh milk and yogurt after printing and painting, and it is in direct contact with the packaged items. The main features are anti-oxidation, good plasticity, and tight sealing, which makes the food shelf life longer. After strictly controlling the degreasing effect of the surface of the aluminum foil, it can fully meet the needs of the market.
The heat seal aluminium foil needs to be heated during the sealing operation, so that the heat-sealing layer and the bottle mouth are fused and sealed. Although the electromagnetic induction sealing machine is a heating device, it is the induction layer on the aluminum foil gasket that actually generates the heat source.
The aluminum foil gasket is heated in a non-contact manner. The reason why the induction layer can generate heat is that under the action of the alternating magnetic field of the electromagnetic induction aluminum foil sealing machine, the induction layer generates eddy current. Under the action of the eddy current, the induction layer generates heat, thereby heating the sealing layer of the aluminum foil gasket.
The sensing layer must be a conductor. Among various metal conductors, aluminum foil is the most ideal one. Because aluminum foil has good ductility, convenient processing, good electrical conductivity, and low price, it has been mass-produced in both the industrial product market and the daily consumer goods market.
When the material of the sealing layer of the bottle has been determined to use aluminum foil, then the thickness of the aluminum foil determines the production cost of the aluminum foil gasket and the working efficiency of the user when sealing.
Generally, 10um aluminum foil can heat the sealing layer to a molten state under the action of induced eddy current, but since the heating time will be a little longer and the heating distance, the thickness of the aluminum foil on the sensing layer is generally above 15um. At present, the common thickness of the heat seal aluminium foil is 15um, 17um, 20um, 25um, 30um, etc.