UV-Curable Coatings Application Process
An overview of the steps in the UV-curable coating process from start to finish.
Process Steps
Click each step below to read more about the process.
- Step 1: Load
- The raw or unfinished parts are loaded on the line.
- Step 2: Preparation
- Any preparation necessary before the parts enters pretreatment, such as masking or cleaning.
- Step 3: Pretreatment
- Depending on the substrate a pretreatment may be required. Types of pretreatments include: zinc phosphate, iron phosphate, zirconium or conductive primers. If you are using MDF or wood products, preheating the MDF prior to coating may be required.
- Step 4: Powder Application
- The UV-curable coating is applied electrostatically with either automatic or hand held spray guns. The types of electrostatic applications are Corona, Tribo, and Bell.
Corona
Corona charging is the most common method used in powder. The powder is dispersed into an airstream, producing a cloud as it exits the gun. The particles pass through a highly charged and ionized corona field at the gun tip applying a strong negative charge to each particle.
Tribo
Tribomatic static charging is the second most common method of spraying a powder coating. The powder is charged by friction when it is moved through the different components of the gun. The friction provides a charge for powder application.Bell
The powder is applied through a Bell applicator, improving evenness of film build across the panel. - Step 5: Melt/Flow
- After the powder is applied it is transformed to a gel state using a heat source. Induction coils, infrared (IR), and convection ovens are the primary heat sources that are used for this process.
- Step 6: Cure
- Finally, the part is exposed to ultraviolet, or UV light which cures the coating instantaneously. Several types of lamps can be used, including UV-microwave, LED, or arc lamps.
- Step 7: Unload
- The coating is fully cured and the part can be taken off the line and packaged without any additional cooling period.