Powder spraying is a mainstream surface treatment process for metal products. The coating thickness directly determines the corrosion resistance, wear resistance and appearance quality of products. Different application scenarios and industries have corresponding thickness standards, and proper thickness control is the key to guarantee product quality.
The standard thickness of conventional electrostatic powder spraying coatings ranges from 60μm to 120μm, which is widely applied to civil hardware, indoor accessories, ordinary guardrails and home appliance shells. If the thickness is less than 60μm, the coating is prone to substrate exposure, pinholes and uneven coverage, leading to a sharp decline in rust and corrosion protection. If it exceeds 120μm, it will not only raise production costs, but also cause defects such as sagging, orange peel texture and reduced adhesion, damaging appearance and service stability.
Thickness standards vary according to service environments. For workpieces used in dry indoor environments such as indoor hardware and cabinet parts, the coating thickness of 60μm to 80μm is sufficient to meet decorative and basic anti-rust requirements while ensuring cost efficiency. For products in semi-outdoor and slightly humid conditions, the recommended thickness is 80μm to 100μm to enhance moisture and mild corrosion resistance.
Workpieces exposed outdoors all year round suffer from sun, rain and wind erosion. For such high-demand working conditions, the coating thickness is suggested to be 100μm to 120μm. For heavy machinery, municipal outdoor components and products with high anti-corrosion requirements, the thickness can be increased to 120μm–150μm as needed, yet it is generally not advisable to go beyond 150μm.
A coating thickness gauge is commonly used for spot checks on planes, edges and welds of workpieces to ensure uniform thickness. To sum up, adopt thinner coatings for indoor products and appropriately thicker ones for outdoor items. Following the general standard of 60–120μm helps strike a balance among service performance, appearance and production cost.
