Liquid Atomization Technology Options:
Conventional – The most established method of air atomization. Used on spray guns for decades. This type uses high velocity air jets to produce a high power atomization which breaks the paint into the smallest particle size of any atomization technology. The conventional technology provides the highest quality finish. Air pressure exiting the air cap during use is typically 40-70 PSI with typical air consumption of 6 to 25 CFM. For more information: Graco Air Pro
High volume Low Pressure (HVLP) – HVLP uses higher volumes of air (11 to 30 CFM) at low pressure (under 10 PSI) to atomize the coating. HVLP provides high transfer efficiency and is limited by Government Environmental Legislation to a maximum of 10 psi atomizing pressure measured at the air cap. For more information: Devilbiss Compact
Low Volume Medium Pressure (LVMP-Complaint-TranTech) – this technology makes more energy available for the atomization process thank HVLP, but delivers transfer efficiencies equivalent to those of HVLP. Air cap pressure is in the area of 25 to 45 PSI while using 9 to 20 CFM for atomization of coatings. For more information: Binks Trophy Gun
Laminar Airflow – this innovative technology introduces atomizing air at the front of the spray gun. It is designed with smooth sweeping air passages, fewer obstructions, and shorter distance between the inlet and air cap. The result is minimal air pressure loss through the spray gun, controlled air flow which results in a complete full spray pattern with minimal air consumption and over spray. For more information: DUX Pressure Feed, www.duxtechnologiesinc.com
Air Assisted Airless – To maximize efficiency, the best features of air spray and airless atomization are combined in this technology. The pattern is formed by the spray tip at between 500 and 2,500 psi fluid pressure and a small amount of air pressure is used to adjust the size of the spray pattern and eliminate “tails”. Air Assisted Airless provides fast application of materials, a soft spray that reduces for overspray and bounce-back, and the ability to penetrate into recesses and cavities. This is especially important where intricate shapes require a consistent film build. For more information: Graco G15
Airless – Fluid atomized by high pressure (usually 3,000-7,000 psi) and pushed through an orifice in the spray tip which is typically .015” – .035” in diameter. The shape of the orifice determines the shape and size of the spray pattern. With airless technology, the size of the atomized particle is larger than other spray methods and therefore typically not used for achieving fine finishes.
Electrostatic – Electrostatic spray finishing combines the mechanical process of atomization with the distributive effects of electrical attraction and repulsion to achieve a high quality efficient product finishing operation. For more information: Nordson Liquid Catalogue, www.nordson.com
Atomization is achieved in liquid systems by air, airless, air-assisted airless, or rotary apparatus. The atomized droplets of coating material are put through a highly ionized zone where the coating particles pick up a charge. Particles are similarly charged, and like charges repel one another causing the particles to form a larger, more evenly distributed spray pattern than a non-electrostatic pattern.
The charged paint particles are drawn towards the grounded object being painted. The paint particles have a negative charge and are attracted to the positive ground of the product being coated.v