NEW DESIGN OF A PLASMA CHAMBER FOR HOMOGENEOUS WEB TREATMENT

This paper describes a plasma treatment and coating system which is us ed to modify polymer web films with a width of up to 0.5 m. The main f ocus of the description is a new design of the plasma chamber geometry , gas distribution (inlet and outlet) and electrodes assembly. An elec trode mounting support has been constructed which enables a quick exch ange of the powered electrode (cathode). This permits a marked extensi on of the real operating time of the system. A second feature is the d esign of the gas and precursor feeding tube, which results in a homoge neous gas supply along the substrate width. This uniform gas flow is s upported by a corresponding design of the exhaust opening. The uniform ity of the plasma process is investigated in an exemplary manner by tr eatment of polyester films with a CF4 plasma and surface characterizat ion by contact angle measurements and electron spectroscopy for chemic al analysis. The measurements showed a good homogeneity of the treatme nt along the width of the polymer film.