Surface activation of a material is used to obtain better adhesion properties. Activation is achieved by increasing the surface energy of the material making it more hydrophilic. This increases the surface wettability and renders the surface adhesive. Activation by plasma treatment is extremely fast, economical, effective and safe to the environment. With a plasma system, an array of different materials such as metals, plastics and ceramics, can be activated.
Surface activation is most commonly achieved by adding oxygen to the material surface. Oxygen surface activation will greatly increase the surface energy of materials such as polypropylene and polyethylene so that they can be adhered to. To measure the extent of activation, water contact angle may be evaluated. After activation, the contact angle of aqueous solutions placed on the activated surface will be greatly reduced. Surface activation with hydrogen plasma can alternatively reduce superficial oxide layers on electronic parts. This plasma treatment will create a reactive, clean metal surface for soldering and bonding.
Modification of hydrophobic, low surface energy materials with plasma activation has a number of advantages over wet-chemical activation methods. Since plasma activation occurs at the atomic scale, it can be used multiple times on a surface if needed. The activation is not harmful to the environment. Furthermore, since no liquid chemicals are used in plasma treatment, plasma systems generate no liquid waste that would otherwise need to be disposed of.
Plasma activation is used in many different industries. For example, in coating aluminum plasma treatment can be used to activate the surface improving its wettability and ultimately adhesiveness. Plasma treatment is also a great way to activate hydrophobic materials such as polypropylene and polyethylene for industrial painting and adhesion applications. For precision mechanics, activation can make functional coatings more wear resistant. Activation using plasma systems is not limited to these fields and can be used in a wide range of different applications.