The process of coating which involves the application of free flowing dry powder on a certain type of metals is known as powder coating. The part which requires the coating is either sprayed or dipped into the dry powder which is electrostatically charged. Then the part is either roasted in a furnace or an oven to carry out the process of curing. The coating is applied on metals used in the making of appliances like refrigerator, washing machine, cars, automobiles and bicycle parts. These days’ new technologies allow other materials like MDF (medium density fiberboard) to be powder coated using different methods.
Types of Coating and Its Production
Powder coating repairs can be divided mainly into two types’ thermoset powder coating and thermoplastic powder coating. The thermoset powder coating involves activation of incorporated crosslinker in the powder which reacts with another chemical group in the powder polymer when baked, thus improving the molecular weight and enhancing the its performance properties. In thermoplastic, there is no reaction or activation which takes place during the process of baking.
The commonly used polymers are polyester, polyester-epoxy, straight epoxy and acrylics. For the production of Powder coating, the Polymer granules are mixed with other talc manufacturing ingredients along with pigment and hardener. The mixture is then passed through an extruder where it is heated and then allowed to cool down into thin sheets or chips which are then ground to make a fine dust.
The coating Process
The coating process involves three basic steps in which the metal to be coated is pre-treated and is then coated with powder before it is subjected to the final process of curing.
Premises & Equipment required for carrying out the process
If you intend to set up your own business then you must know that you would be in need of a place in an industrial Zone as you would be dealing with resins, pigment, curing process and chemical additives. You would need an approval via a permit and license to set up the coating plant.
Among the spraying equipment what is mainly required is a Spray gun to spray with and spraying Booth or cabin or room to spray the object in them. It is mandatory to have ventilation and exhaust facility to avoid exposure to toxic fumes as per the local laws for Health and safety.
Oven – The curing process is carried out at very high temperatures in either a convection oven or infrared cure ovens. When a thermoset powder is exposed to high heat it melts and flows out and eventually reacts chemically to form a higher molecular weight like structure. In order to reach the full cure stage and establish full film properties for which the materials are designed a certain higher degree of temperature is required for a certain period to get the right finish.
It is very important to part prepare the substance to be powder coated. The removal of oil, soil, lubrication greases, metal oxides, welding scales etc. is vital before the powder coating is carried out. The removal can be carried out by vivid chemical and mechanical treatment. The treatment selection can be done on the basis of the size of the material to be powder coated, the type of grease or soil to be removed and the final performance required from the material.
If you have any need of powder coating repairs requirement then contact RM Coating Supplies in Melbourne they would help you with any service or product required pertaining powder coating.