Light as a tool: Using vacuum-UV excimer radiation for activation of polymer surfaces

The activation of polymers using a commercially available Xe 2*-excimer lamp was studied. For activation, an irradiation step by using simply VUV-light at a central wavelength of 172 nm was performed. Material independent trends could be deduced and several exemplary material-specific properties were observed. Furthermore, studies to optimize the process parameters with regard to industrial framework requirements were made (e.g. cycle time, distance, required surface energy). For the investigated polymer materials, including PP, PE, PET or PVC it is possible to increase the surface energy up to 72mN/m. For PET, the activation is time stable at least up to 15 days. What can be shown by the XPS analyses of PE and PPGF30, the VUV-activation is based on the incorporation of additional oxygen into the polymer surface. Finally, a comparison between VUV-irradiation and low pressure plasma activation was made showing a similar surface energy level.