Effect of Water-jet on Laser Paint Removal Behaviour

The laser paint removal behaviour with water-jet assist laser has been investigated using Yb- fiber laser. The conventional laser paint removal process with gas-jet assist usually leaves behind traces of combustion product i.e. ashes on the surface. An additional post-processing such as light-brushing or wiping by some mechanical means is required to remove the residual ash. In order to strip out the paint completely from the surface in a single step, a hybrid laser process which utilizes a water-jet along with laser beam has been developed. A coaxial water-jet along with a high power fiber laser beam removed the paint and residual ashes very effectively. The specific energy, defined as the laser energy required removing a unit volume of paint was found to be marginally higher than that for the gas-jet assisted laser paint removal process. However, complete paint removal was achieved with the water-jet assist only.