Plasma surface treatment technology Plasma treatment materials increase wettability

• Categories:Industry News
• Author:plasma cleaning machine-surface treatment equipment-CRF plasma machine-Sing Fung Intelligent Manufacturing
• Origin:
• Time of issue:2021-05-14
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(Summary description)        Plasma surface treatment technology can effectively change the wettability of the surface. It is recommended to paste the material as soon as possible after plasma treatment. But once the treated surface comes into contact with paint, ink, adhesive, or other materials, the bond becomes permanent. Plasma surface treatment technology         What is plasma surface treatment technology?         The surface energy of solid materials and the requirements for surface treatment of polymers. Plastic materials often need to be adhered to metal or other plastic materials, or simply printed on the surface of the plastic. To do this, the liquid adhesive or ink should be able to wet the surface of the material. Plasma treatment technology can achieve this effect.         The wettability depends on a special property of the surface: the surface energy commonly referred to as surface tension. The unit of surface energy, such as surface tension, is mN/m. The surface energy of the solid substrate directly affects the wetting of the surface by the liquid. The measurement of the contact angle can easily prove its wettability. The contact angle is the angle between the tangent and the horizontal plane of the solid surface at the point of contact. When the water droplets are placed on a smooth solid surface, the water droplets will be dispersed on the substrate. If it is completely wetted, the contact angle will be close to zero. Conversely, if the wetting is local, the contact angle can be balanced between 0 and 180 degrees.         The greater the surface energy of the solid matrix against the surface tension of the liquid, the better the wettability and the smaller the contact angle; to make the liquid and the surface of the material form a good bond, the surface energy of the material should be greater than about 2-10mN/m of the liquid tension. This type of polymer material has the characteristics of chemical inertness, low friction coefficient, high wear, puncture resistance, tear resistance and so on. However, these polymers have poor wettability, causing problems for designers to bond and decorate materials. Plasma surface treatment technology can improve the wettability of the material by increasing the energy on the surface of the material, and affect the performance of the adhesive by creating connection points. .         There are always free electrons accelerating and ionizing the gas during high-voltage discharge in the air gap. When high-speed electrons collide with gas molecules, when the discharge is strong, there is no momentum loss, and an electron avalanche phenomenon occurs. Put the plastic part into the discharge channel, and the electrons generated during the discharge process have about 2-3 times the energy of impacting the surface, thereby breaking most of the molecular bonds on the surface of the substrate. This creates active free radicals. Such free radicals exist in oxygen and can react quickly to form a variety of functional groups on the surface of the substrate. The functional groups generated by the oxidation reaction can effectively increase the surface energy and strengthen the chemical bond with the resin matrix. These include carbonyl (-C=O-), carboxy (HOOC-) which is hydrogen peroxide (HOO-) and hydroxyl (HO-) groups. Plasma surface treatment with high-voltage discharge only changes the surface characteristics and does not affect the volume characteristics of the material.