Steel Liquid Arcing Spraying (LAS ) is an advanced and efficient powder spraying technology that covers a wide range of applications. It is a process whereby particles of metallic powder are melted and then projected onto the substrate by two arcs of electricity created by two electrodes. The heat of the electric arcs melts the powder and forms a liquid spray of metallic particles that are then splatted onto the substrate.
LAS offers a range of advantages when compared to other powder-spraying processes. The molten particles are projected at a much higher velocity than that of conventional processes and this enables them to impinge on the substrate more effectively, resulting in a superior adhesion of the powder coating layer. LAS is also more efficient as it eliminates the need for preheating or post-heating that are associated with some conventional powder coating processes.
For steel liquid arcing spraying, the process consists of preparing the substrate, mixing the powder with the liquid adhesive, setting up the equipment, heating the substrate and spraying the powder onto the substrate.
The first step in the process is preparing the substrate. This involves cleaning the steel surface to ensure that there is no dirt, grease, paint or other contaminants on the surface that may affect the adhesion of the coating. Usually, this is achieved through surface degreasing and/or shotblasting.
The next step is to mix the powder with the liquid adhesive. This enables the powder to be suspended in the adhesive in order to enable the particles to “float” or “stick” to the substrate during the spraying process. Different types of liquid adhesives are available for different coating requirements.
The third step is to set up the equipment. This involves setting the power supply to the correct voltage, amperage and arc time. The distance between the electrodes and the substrate must also be correct in order to ensure an even coating. It’s important to note that the powder feed rate must also be adjusted in order to ensure an even coating.
The fourth step is to heat the substrate. This is usually done with an induction heater, but can be done with other heating methods such as a heat gun or furnace. It is essential that the substrate is within the specified temperature range for the powder coating process to be successful.
The fifth and final step is to spray the powder onto the substrate. The powder is fed into the gun and the current is then switched on. The arc between the two electrodes forms a plasma that melts the powder, causing it to be splatted onto the substrate. The spray pattern can be adjusted for different requirements such as for uniformity and thickness.
Steel liquid arcing spraying is a simple and efficient method for applying powder coatings onto steel substrates. It ensures a superior adhesion and eliminates the need for pre-heating or post-heating. The simplified five step process ensures that it can be completed quickly and with minimal waste.
