Chapter 4: High Pressure Airless Spray Method
It is a paint spraying which use high pressure (more than 40 Bar) to push material paint out of nozzle without air pressure to mix in paint. The surface object are covered by material paint only. No air bubble to mix and make damage surface to be not smooth. Low spread rate to avoid disturb environment. Spraying with high speed and also deliver large quantity paint in the same time to complete work in a few time.
Airless spray gun and airless feeding unit of WAGNER are compatible to use under maximum pressure around 110 Bar to 400 Bar.
Characteristic of Airless Spray
The below picture are the example of airless spray procedure. The main principle, free air to mix in spray pattern. First step, material paint are delivered out from nozzle (1) with high speed. Second step is the paint disruption (2) to atomize (3). All procedure are done by high pressure spraying and use a few second for all process. Importantly, the high speed flow are danger to physical user so you may see tip guard in example picture (The cap which hold the nozzle) to protect finger from paint touching.
Example of Airless Spray Gun
Droplet size on surface object
Droplet size determine the resolution of paint atomizing. Large provide resolution less than small size but it depend on job specification and 3 factor are following below;
1. Nozzle Size
Nozzle bore is similar to exit gate from spray gun. Droplet will be larger by following widely size of gate.
2. Material Pressure
It is the push force which move paint out of spray gun. More pressure, spray will be faster but droplet size will be smaller as pressure reduce droplet size.
3. Paint Viscosity
Viscosity affect to deliver hardly paint out of spray gun. High viscosity will make matterl paint to be materialcked sitr and increase droplet size. Using unsuitable nozzle and pressure will be spray slowly paint or unable to spray.