Mobile plasma activation of polymers using the plasma gun

Surface activation of hydrophobic polymers is important prior to effective painting and glueing. The purpose of the plasma gun is the activation of polymers under normal pressure using a plasma excitation. Its function principle is based on a gas jet pump. Under low pressure a plasma is burning induced by an electrical discharge. The activation process takes place under ambient pressure and temperatures. It causes no thermal stress to the substrate. The performance of this plasma tool depending on axial and radial distance to the substrate, plasma power, and process time has been investigated. Different types of polymers have been compared. Polymers like polyethylene, polyamide, polystyrene, polyoxymethylene, polypropylene, and polycarbonate show good activation results. This tool can be used especially for thermolabile plastic substrates and bulky goods, when a vacuum batch process is not possible. (c) 2005 Elsevier B.V. All rights reserved.