Powder Coating

Powder Coating is a young prodedure in the surface technology. It developed rapidly in the last 20 years. Because of being solvent-free it's an interesting product for environmental protection.

Procedure

Rasin is mixed with pigments and additives which creates the mass. A certain temperature and pressure knead the mass to  a homogeneous mash. After cooling the mash is being grind to a powder. We order these powders from various source suppliers.

Electrostatic Spray Application

Electrostatic Spray Application uses a fluidized bed as a feed hopper to hold the powder and fluidize it so that it can be pumped to the tip of a spray gun using compressed air for transport from the feed hopper to the gun tip. The spray gun is designed to impart an electrostatic charge to the powder material and direct it toward a grounded workpiece. This process makes it possible to apply much thinner coatings with a wide variety of decorative and protective features.The electrostatic charge ca be imparted with voltage, called corona charging, or by frictional contact with the inside of the gun barrel, called tribo charging.In a corona charging system, a voltage source generates current through a voltage cable that carries it to the powder gun tip. Powder is pumped through the gun and out of the gun tip using compressed air compressed air. As the powder passes through the electrostatic field at the gun tip, it paicks up a charge and is attracted to a grounded substrate. The part is then conveyed into an oven for curing of the powder. In the cure oven, the powder melts and cross-links to a hard film to complete the process. Electrostatic spray application of powder is the most common application method. The parts to be coated are cleaned, dried, and cooled the coating is applied and cured at the required temperature for the required time and then cooled for removal from the line. An electrostatic spray application system includes a delivery system and charging system. The basic pieces of equipment that make up a single application unit are:

  • feed hopper
  • powder spray gun
  • electrostatic power source
  • controls

These components are connected by hoses and cables and all the necessary regulators and fitting to complete the package.The powder path through the system will abrade surfaces and may impact fuse and cause restriction to flow. The wear parts in the venture pump and gun barrel should be checked frequently and replaced when the amount of wear causes flow problems. Hoses should be kept as short as is practical to avoid loops of hose that will restrict flow and contribute to impact fusion.

Advantages

  • Coating is eco-friendly and solvent-free
  • The layer thickness of just one coating process is good enough to prevent corrosion
  • Extreme cross-linking particles create a high scratch resistance an impact strength