Powder Painting - Galma, a.s.
Powder coatings are among the single-layer coating systems used most frequently for metal surfaces. From the perspective of ecology is one of the benefits that powder does not contain solvents. From the perspective of the technology itself, especially in relation to the surface pretreatment prior to application, the application of powder coatings require a specific approach.
Powder coatings are applied by spraying in an electrostatic field. Using the electrostatic field is electrically charged powder particles, while the painted object is grounded. The resulting electrostatic force is sufficient to create a sufficient layer of powder on the subject. It will remain on site until the melt and adhere to the surface.
Generally, the surface material to be powder coated must be absolutely dry and clean. Prescribed finish components before the process is necessary condition for obtaining high-quality and durable coating, or layer with corresponding properties.
- Self-application of powder coating
Prelimitary material treatment
the main objective of mechanical, chemical or electrochemical interim adjustments is to achieve the desired quality finishes, such as good adhesion, corrosion and mechanical resistance, hardness, etc.
1. Mechanical pretreatment
- spot blasting
The mechanical pretreatment is followed by mechanical removal of dust, usually in the chemical pretreatments.
- Degreasing (alkaline degreasing liquids or organic solvents)
- ferric phosphate-based phosphate
Among the various types of chemical pretreatments and after are included multistage rinsing water.
- Preheated air temperature of about 100 to 120 C
2. Powder coatings
Powder coatings are classified in the group of industrial paints. They consist of a mixture of resins, pigments, and other raw materials such as powder supply colors, hardness, gloss, matt or desired depth, creating structural surfaces, etc.
This mixture has the consistency of dry powder. Powder coating for application to dilute anything, nor in no fluid does not dissolve. It is applied in powder form by means of compressed air one of the great advantages of powder coating colors are good ecological and environmental conditions of operation parameters of the final coating properties compared with the finish of most common liquid coatings. Powder technology do not use solvents, varnish is applied in powder state and recirculation technology with powder in the application device is minimal waste application. Additionally, you can use the remaining powder (spraying of waste), under certain conditions to regenerate and then reused.
2.1 Types of powder coatings
Widespread and massively used are thermosetting powder coating. by
carriers are divided into the following basic types:
- epoxy (EP)
- epoxy polyester(PEP), a hybrid, also become popular or "mixes"
- polyester powder coatings (PES)
- polyurethane powder coatings (PUR)
- acrylic powder coating (AC)
3. Curing – polymerization
Pre-heated air, temperature and time recommended by the paint manufacturer - typically 170-200C 20 min.