the picture of the Hot-sale Electrostatic powder coating plant


1.Brief Introduction:

 

Powder coating is a type of coating that is applied as a Free-flowing, dry powder. the main difference between a conventional liquid Paint and a powder coating is that the powder coating does not require a Solvent to keep the binder and filler parts in a liquid suspension form. the Coating is typically applied electrostatically and is then cured under heat to Allow it to flow and form a "skin". The powder may be a thermoplastic Or a thermoset polymer. It is usually used to create a hard finish that is Tougher than conventional paint. Powder coating is mainly used for coating of Metals, such as household appliances, Aluminum extrusions, drum Hardware and automobile and Bicycle parts. Newer technologies allow Other materials, such as MDF (medium-density Fibreboard), to be powder coated using different methods.

the Powder coating process

the Powder coating process involves three basic steps:

Part Preparation or the pre-treatment

the Powder application

Curing

2.Techincal parameters:

Part Preparation processes and equipment

Removal of oil, dirt, lubrication greases, metal oxides, welding scale etc. Is Essential prior to the powder coating process. It can be done by a variety of Chemical and mechanical methods. the selection of the method depends on the Size and the material of the part to be powder coated, the type of impurities to be removed and the performance requirement of the finished product.

Powder Application processes

Example of powder coating spray guns

the most common way of applying the powder coating to Metal objects is to spray the powder using an electrostatic gun, or corona gun. the gun imparts a positive electric charge to the powder, which is then sprayed Towards the grounded object by mechanical or compressed air spraying and then Accelerated toward the workpiece by the powerful electrostatic charge. There Are a wide variety of spray nozzles available for use in electrostatic coating. The type of nozzle used will depend on the shape of the workpiece to be painted and the consistency of the paint. The object is then heated, and the powder Melts into a uniform film, and is then cooled to form a hard coating. It is Also common to heat the metal first and then spray the powder onto the hot Substrate. Preheating can help to achieve a more uniform finish but can also Create other problems, such as runs caused by excess powder. 

 

Curing

3.Performance features:

When a thermoset powder is exposed to elevated Temperature, it begins to melt, flows out, and then chemically reacts to form a Higher molecular weight polymer in a network-like structure. this cure process, Called crosslinking, requires a certain temperature for a certain length of Time in order to reach full cure and establish the full film properties for Which the material was designed. Normally the powders cure at 200 C (390 F) for 10 minutes. The curing schedule could vary according to the manufacturer's Specifications. The application of energy to the product to be cured can be Accomplished by convection cure ovens, infrared cure ovens, or by laser curing Process. The latter demonstrates significant reduction of curing time.