What makes a good powder coating?

How to Judge the Quality of Powder Coatings?

The primary application of powder coatings is to coat and protect metal workpieces. Beyond the basic physical and chemical performance requirements, the first key factor is quality consistency. This includes both operational stability and color stability — each batch should maintain minimal color variation to avoid noticeable differences between production runs.

The second key factor is coating performance. High-quality powder coatings provide excellent coverage and strong adhesion to the workpiece during spraying. This means less powder falls to the spray booth floor or gets carried away by the dust collector, resulting in a lower volume of reclaimed powder and secondary collected powder.

Powder Coating Cost Calculation

The true cost of powder coating lies in the actual amount of powder that remains on the workpiece. To determine this, weigh the workpiece (kg) before coating and again after coating. The difference gives the exact weight of powder applied (kg). Multiply this weight by the unit price per kilogram to calculate the real coating cost for that workpiece.

If film thickness needs to be considered, measure the coating thickness and adjust the calculation accordingly. Additionally, when accounting for overspray collected by the dust collector and general production loss, the total powder consumption can be roughly estimated at up to 50% higher than the applied weight.

Which Powder Coatings Can Help Reduce Costs?

To lower coating costs, the goal is to reduce the powder weight needed per workpiece:

Weight = Surface Area × Film Thickness × Density

• Surface area is fixed by the workpiece.
• Film thickness is generally controlled by spraying method or equipment.
• The variable factor is powder density, which typically ranges from 1.1–1.8 g/cm³ — a difference of up to 1.6 times between the lightest and heaviest powders.

Therefore, it’s not always cost-effective to focus solely on price per kilogram. A slightly higher-priced, low-density powder may ultimately deliver greater coverage and lower overall cost than a cheaper, high-density powder with less coverage.

Purpose and Nature of Powder Coatings & Coating Principle
Purpose: Powder coatings enhance the appearance and protect metal or conductive surfaces from corrosion. Like clothing for people and gold for Buddha statues, they provide vibrant colors, varied gloss, and decorative textures.

Nature: They are finely ground, colored plastic powders made by blending resins, pigments, additives, and fillers, extruding the mixture, cooling it into sheets, and grinding it into powder particles.

Coating Principle: The powder adheres to metal via electrostatic attraction, then melts and cures upon heating to form a solid coating.

The process produces no volatile emissions or wastewater; excess powder is collected and reused, leaving only solid waste. This makes powder coatings an environmentally friendly alternative to traditional solvent-based coatings, aligning with global energy-saving and carbon-reduction standards.