1) Powder coatings need dedicated electrostatic spraying and high-temperature curing, so they cannot be used on heat-sensitive substrates such as rubber and plastic, nor on thick or oversized parts that cannot be baked; thick single films make thin coats hard, equipment is costly and energy-intensive, material is wasted, color change is troublesome and repair is impossible. 2) Electrocoat requires electricity and a conductive workpiece; it is unsuitable for multi-metal assemblies with different conductivity or heat-sensitive parts, small-batch production, or large equipment, needs strong technical support and costs far more than water-based. 3) High-solid coatings (>=70% volume solids) still contain less solvent than ordinary solvent paints but remain oil-based and are less eco-friendly than water-based, with higher process requirements and overall cost.


