Effect of low temperature plasma treatment on pet film surface plasma treatment on pet film performance:
PET film material body is widely used in packaging, anti-corrosion coating, capacitor preparation, magnetic tape and even medicine because of its good fatigue resistance, strong toughness, high melting point, excellent isolation performance, solvent resistance and excellent anti-wrinkle performance. Various technical fields such as health.
Low temperature plasma treatment of pet film surface
However, due to its low surface free energy, PET film has poor processing properties such as wettability, adhesion and printability, which greatly limits its application in actual production. Therefore, for PET film materials, it is very necessary to select an appropriate method for surface modification while retaining the inherent properties of the body.
Plasma treatment technology is a gaseous treatment technology that combines physics and chemistry, which has the characteristics of high efficiency, energy saving, and environmental protection (no water consumption). What is important is that plasma treatment is generally carried out under low temperature conditions, and its depth of action only involves the extreme surface layer of the material, so it will not damage the bulk properties of the material.
Effect of low temperature plasma treatment on the surface morphology and structure of PET film
(1) The surface of the untreated PET film is smooth as it is, and there are very small amounts of impurities on the surface of the film. As the plasma treatment time of the sample increased, some irregularly shaped flake-like structures appeared on the surface of the plasma-treated PET film, and the surface roughness of the film also increased. A large area on the surface of the PET film presents a white fine grain structure. In fact, the rough structure is composed of nano-sized fine particles. The phenomenon that the plasma treatment makes the film surface rough indicates that the plasma treatment has an etching effect on the PET film.
(2) The changes of the PET film before and after plasma treatment can be seen. After plasma treatment, the relative content of carbon element on the surface of the film decreases, and the content of oxygen and nitrogen increases significantly. The longer the time, the more obvious the increase in the ratio of oxygen/carbon and nitrogen/carbon content on the surface of the sample. This indicates that plasma treatment introduces some new oxygen-containing functional groups into the surface of the PET film, and these oxygen-containing polar groups play an important role in improving the hydrophilicity of the film surface.
(3) Comparison of the surface contact angle and surface free energy of the PET film before and after plasma treatment. It can be seen that the surface free energy of the untreated PET film is low and the hydrophilicity is poor.
Plasma treatment can effectively increase the surface energy and hydrophilic properties of the membrane. When the polar components on the surface of a substance increase, the hydrogen bond force or dipole moment force contributed by these polar components in the vertical direction of the interface can greatly enhance the adsorption force of water molecules on the surface of the substance. Thereby increasing the surface free energy. Plasma treatment makes a large number of oxygen-containing polar groups introduced on the surface of the film (such as C-O/C-N.C=O, C=O-O, etc.) make a major contribution to the improvement of the surface free energy of the PET film. The increase of surface free energy of PET film will inevitably bring about the obvious improvement of its surface wettability, bondability and printability.