Powder coating is a coating type that is used as a free-flowing, dry powder. In contrast to the conventional liquid coating supplied via a solvent that evaporates, the powder coat is generally electrostatically applied and then heated or ultraviolet light. The powder can be either a thermoplastic or a polymer thermoset.

It is often used to create a more rigid finish than conventional paint. For covering metals, such as appliances for households, aluminum extrusions, drum hardware, car, and bicycle frames, powder covering is used primarily. Advances in powder coating technology, such as UV curable powder coating, make other materials such as plastics possible; composites, carbon fiber, and the powder-coated MDF (medium-density fibreboard) for minimal time for processing such components to the heat and oven stay long.

Powder Charging-

Powder Charging is the process of charging the power in the gun to coat the surfaces.

There are two ways of charging the powder.

1. External (Corona)
2. Internal (Tribo)

External Charging or Corona- When 100KV is released at the gun tip (corona discharge), it breaks the air between the gun tip and object. The breaking of the air gap is known as ionization, in which millions of ions of both the polarity i.e., positive and negative. The positive ions will attract the gun tip as it has negative polarity (opposite charge attracts) and gets earthed.

The powder releasing from the gun will collide with negative ions in the field and will acquire a negative charge due to the collision. The charged powder will move towards the object, which is earthed. This is how the powder is charged externally.

Internal Charging or Tribo- Tribo type gun powder is charged by friction. The powder moving in the gun gets rubbing action with the charge media and gets charged. As the powder is charged in the gun itself, it is known as an internal charge. There are two types of guns in Internal changing are Automatic Turbo Gun and Manual Turbo Gun.

Mitsuba Systems gun

With guaranteed 100 KV generation coupled with a range of nozzle and muzzle ensures higher coverage per KG of powder. Stringent quality control, high standard of components, and innovative design will consistently coat for time to come. The coating job is very critical. The Mitsuba machine has user-friendly features like Performance Monitor, Infinity corona resettable cascade, IP 54 International standard dustproof panel, CE certification.

Different types of nozzle and muzzle affect the transfer efficiency. The nozzle sprays the powder. If overspray is less, efficiency will be higher. An appropriate nozzle can give the highest FPTE and will reduce the overall coating cost.

Powder, thermosets and thermoplastics, and UV curable powder coatings are the kinds There are The powder coating finishes thermoplastic become liquid and when heated very weak. This removes chemical bonds. The powder coating is reversible and reusable by this process.

Compared with thermoelectric coverings, the thermoplastic coating tends to be thicker and, therefore, more durable. They can therefore be used in a variety of stuff from metal, automotive components, and refrigerators.

The fact that thermal powder forms chemical bonds once it’s cured makes recycling impossible differs considerably from thermoset powder. It is suited for high heat zones because the connections prevent it.

How is powder coating done?

The powder coating process involves three primary stages: pre- or preparation of the part, applying the powder, and curing.

Preparation of the section

Before the powder coating procedure, removal of oil, dirt, grains for lubrication, metal oxides, welding scale, etc. It can be carried out with a range of chemical and mechanical procedures.

The choice of the method depends on the sizes and material of the powdered part, the kind of impurities to be removed, and the finished product’s performance requirements. There is low surface stress for some thermal-sensitive plastics and composites, and to improve powder sticking, plasma treatment may be required.

Powder application processes

Metal objects usually use an electrostatic weapon to spray the powder. The powder coating can be filled with corona weapons. The weapon transfers a negative charge to the powder-filled by mechanical or compressed air pumping onto the grounded object and then accelerated with the solid electrostatic charge to the workpiece. A wide range of spray dots for electrostatic covering is available.

The type of dust used depends on the shape and the consistency of the workpiece to be painted. The item is then heated, and the powder melts into a homogeneous film and cooled into a hard layer. Heating the metal is also typical; put the powder on the hot substratum first and thereafter. Preheating can contribute to a more uniform finish but can also create problems like excess powder runs.

Curing

The last step is to insert your product into a specially designed Powder Curing Oven after powder-coated. They usually run from 325° to 450° Fahrenheit. The temperature stabilizes as soon as the oven reaches a temperature. The coated products shall be exposed for a certain period to precisely heated air.

After the process of curing has been completed, the parts are removed and cooled before handling. Electric furnaces or gas or LP-fueled heat systems are used for ovens. These standard ovens usually rely on heated air moving over the convection curing elements.

Advantages of Powder Coating

Friendly environment: This is an eco-friendly option because it can be reused and recovered. In particular, unlike thermosets, thermoplastic coatings can be very quickly reshaped. The powder is used with minimum waste precisely, in contrast to paint, which has many excess sprays.

You can expect some 5% or less waste, and the fact that solvents are not necessary is a significant plus. Powder coating does not release volatile organic compounds, which may damage the environment. It is also safe to use, and although it is still recommended to wear protective gear, it poses no health threat as many as other finishes.

Expenditure: The early experience seems significant and possibly overwhelming for some with powder layer finishes. However, over time, the coat is much lower than other finishes.

Polish look: Polish look. When powdering metal is used, it is quite easy to make a polished look. It is effortless to clean because it repels chemicals, moisture, and other elements.