What is Powder Coating? – Powder coating is the application of a flowing, fluidised powder which when baked in a powder coating oven, flows as a liquid before cooling to form a hard and durable finish.  Typically used for metal substrate, TD Finishing powder coating equipment has been used to paint everything from bicycles to car parts and domestic boilers to Architectural aluminium.

So how does it work? 

Typically, there are three stages to a powder coating system:

Stage one involves the preparation of the material.  This can be done in several ways and depending on the final finish requirements, can range from hand wiping with cleaner to shot-blasting followed by a full online pre-treatment plant.  Our Pre-treatment plants work in one of two ways, an online spray for conveyorised plant or an automated dip tank with gantry system for basket loading of longer, or higher quantities of material.  The pre-treatment regime is designed to clean and prepare the surface of the substrate allowing for good, reliable adhesion of the powder coating.  TD Finishing can assist you with working out the correct pre-treatment regime for your business.  This stage is followed by a drying oven.

Stage two, once dried and cooled to a suitable temperature, the second stage involves the careful application of powder.  Electrostatically charged on leaving the gun, the positive (+ve) coating is attracted to the grounded substrate material and held in place by the electric force.  The application equipment is required to ensure sufficient charge of the particle as well as field strength to prevent the powder bouncing off or falling from the substrate before curing.  For fluidised beds or fusion bonded epoxy coatings the product is heated during the drying stage for the purpose of melting the powder in to a green-cured state before moving to stage three.

 

Stage three, once the substrate is fully coated the third stage involves heating the product, in a powder coating oven to the required temperature, and then dwell until the powder has fully flowed across the surface.  The times and temperatures will vary depending on such factors as the powder, thickness or gauge of material and product weight.  But, typically around 180-200 degrees for 15-30 minutes is sufficient.  Critical to this part of the process is ensuring the temperature uniformity of your oven is such, that all parts of the product cure evenly.  TD have many years’ experience in powder coating equipment and understand the importance of air movement within the oven whilst simultaneously balancing the flow so as to avoid any significant disturbance of the powder prior to jelling.  

TD Finishing expertly supply online conveyorised powder coating systems, manual & monorail conveyors, power & free systems, standalone box ovens, as well as infrared ovens for simple one-dimensional products, or as a pre-gel system to prevent cross contamination during a colour change.  We can also supply equipment for wet spray systems where required.

So, to find out how TD Finishing could help you, Call us today on 0121 520 8884 or email info@tdfinishing.co.uk.  

If you enjoyed reading this blog you may also like to read our previous article on powder coating services for GKN.

 

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