Surface treatment of an epoxy resin by CO2 laser irradiation

The influence of CO2 laser radiation on the surface properties of a lamination resin (temperature resistant up to 120 deg C) which is used for carbon fibre-reinforced plastics (CFRP) is examined. It is shown by XPS and infrared spectroscopy that the hydroxy groups of the resin are eliminated by the laser radiation. Using a carbon dioxide atmosphere, also deeper parts of the resin are influenced compared to the treatment in air. The reproducibility of the bond strength is higher for the laser-treated samples than for untreated samples if a room temperature-curing adhesive is used, but the bond strength itself is lower. Laser treatment shows no influence at all if a hot-curing adhesive is used.