Main Factors Affecting the Quality of Barrier Aluminized Films bags

Main Factors Affecting the Quality of Barrier Aluminized FilmsBarrier property The most important quality index of aluminized film is the barrier property of the film. There are many factors affecting the barrier properties of aluminized films, the most important of which are the density of the aluminized layer, the thickness of the aluminized layer, and the bond fastness between the aluminized layer and the plastic film. two aspects of film quality.1. The main equipment factor that affects the quality of plastic film aluminizing is the vacuum degree of the evaporation chamber. High-level equipment is the basis for obtaining high-barrier aluminized films. Without high-level coating equipment, it is impossible to produce high-quality aluminized barrier films. Generally speaking, the higher the vacuum degree is, the better the evaporation effect of the aluminized film will be, the density of the coating layer will increase, and the barrier property will also be significantly improved. special attention.In the production process of barrier aluminized films, the most frequently encountered is the influence of the vapor-deposited base film on the quality of the vapor-deposited film, so many literatures have discussed this aspect.For high-quality aluminized film, the aluminized layer must be firmly attached to the surface of the film. Therefore, to improve the aluminized effect of the film, it is required to enhance the adhesion fastness between the aluminized layer and the surface of the film. Here is the attachment mechanism,BOPETThe surface structure properties of the films and their influencing factors are briefly introduced.2. Attachment mechanism: Plastic films generally have good chemical stability and lack active groups on the surface, so it is usually difficult to chemically react with the aluminum layer to form chemical bonds, and the combination between the aluminized layer and the plastic film is usually through intermolecular. Therefore, when discussing the bonding fastness between the aluminized layer and the base film, it is necessary to understand the interaction between molecules. As we all know, the intermolecular forces include van der Waals forces and hydrogen bonds. Van der Waals force includes orientation force, inductive force and dispersion force, among which the orientation force is the attractive force generated by the permanent dipole moment of polar molecules through electrostatic interaction, and its action energy is the highest, which is1.2X104~2.1X104J/md;The inductive force is the force generated by the action of polar molecules on other polar molecules and non-polar molecules, and its action energy is0.6X104~1.2X104J/mol; the dispersion force is molecular”Instantaneous Dipole Moment”The force generated by the interaction generally exists between non-polar molecules, between polar molecules, and between polar molecules and non-polar molecules, but the dispersion force is weak, and the dispersion energy of small molecules is generally0.8X103-8.4X103J/mol;Hydrogen bonds are functional groups that contain hydrogen in a moleculeAHand atoms in adjacent moleculesBThe weak chemical bond between the molecules formed, the bond energy is2.IX104-4.2X104J/mol, hydrogen bonds are less energetic than chemical bonds, but much larger than ordinary van der Waals forces. To improve the bonding fastness between the plastic film and the aluminized layer, the plastic should be as high as possible.