A SF₆ RF plasma reactor for research on textile treatment

This research concerns the development of a SF₆ RF discharge at low pressure in a small reactor for industrial applications. The plasma is produced in the pressure range 0.05-1 mbar by a RF supply. The pumping system sustains a flowrate of about 50 cm s^-1, with residence time in the discharge of about 0.2 s at a pressure of 0.1 mbar. The discharge parameters were measured at a low operation power. Measurements were performed by means of movable electrostatic probes and a photodiode. Particular care in the analysis of the data proved to be necessary due to the presence of a substantial amount of negative ions. The reactor has been employed for textile treatment in order to modify the surface properties of the fibres. Favourable operating conditions leading to an improved hydrophobicity of the textiles were achieved.