Powder coating services are a type of finishing process used to apply a protective and decorative coating to various types of metal surfaces. This method is preferred over traditional liquid painting because it provides a more durable and even finish. Powder coating is widely used in industries such as automotive, manufacturing, architecture, appliance, and more.
Here’s an overview of the powder coating process:
Surface Preparation: Before the powder coating can be applied, the metal surface needs to be properly prepared. This involves cleaning the surface to remove any oil, grease, dirt, or rust. Abrasive blasting or chemical cleaning may be used to achieve the desired surface condition. This is the first step and the most crucial one as it forms the foundation of forthcoming steps for getting the desired colour and finish. Metal dip timings and chemical concentration in complete process must be taken care of as it plays very important role to achieve perfection. Major deviations from dip timings and chemical concentration can destroy metal surfaces which sometimes cannot be reversed and repaired. It is strongly recommended that this step must be carried by experienced personnel so that human error can be avoided to an extent. Now a days, automated surface treatment lines have been introduced to minimize human errors and save both time and cost.
Powder Coating Application: Once the surface is clean, the powder coating is applied using an electrostatic spray gun. The gun charges the dry powder particles, creating an attraction to the grounded metal surface. This electrostatic attraction ensures an even and consistent coating. Powder application requires an electrostatically charged chamber usually called spray booth in which metal substrate to be powder coated is hanged and dry powder is sprayed onto the piece to cover the metal surface evenly and completely. Spray booth usually comes in two types, single and back to back spray booth which have different purpose and requirement. Single spray booth is used in small to mid-sized plants and back to back spray booths are used in large and medium size conveyorised plants to achieve uniform coating and fast production. For variety of products of different shape and sizes manual powder coating guns are used and you will find automatic reciprocator guns for same product shape and size in large volume.
Curing: After the powder coating has been applied, the coated metal is moved to a curing oven. The curing process involves heating the metal to a specific temperature, causing the powder particles to melt and flow together. This forms a continuous and protective film on the surface of the metal. Curing or baking is very important step after powder application. Curing of white family colours must be taken care of out of other dark and metallic shades as over baked metal surface can change colour of product from white to crème which is very difficult to repair and decoating is required followed by recoating the surface which involves huge cost. That is why it is recommended to use automatic burners on ovens which keep track of time by itself and cuts off automatically when set temperature and time is achieved. It is important to keep in mind the combination of temperature and time for different metals products to achieve desired colour and finish.
Cooling and Inspection: Once the curing process is complete, the metal is allowed to cool down. After cooling, the coated surface is inspected for any imperfections or coating irregularities. If necessary, touch-ups or re-coating may be performed.
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