The crack resistance of spray-coated cable tray in vibration environment is affected by multiple factors. From the perspective of substrate selection, galvanized steel sheet substrate exhibits better vibration resistance than cold-rolled steel substrate due to the stress buffering effect of zinc layer. In terms of powder type, epoxy resin coating has high hardness but high brittleness, and is prone to microcracks in long-term vibration environment; in contrast, polyester resin is more adaptable to vibration environment with better toughness (elongation is usually >5%). The coating thickness also needs to be strictly controlled. Too thick (>120μm) will reduce flexibility. It is recommended to keep it in the range of 60-100μm.
Actual application performance shows that qualified spray-coated coating can pass ISO 6272 impact test (5N·m impact without cracking), but in long-term vibration environment, it is still necessary to pay attention to problems such as structural resonance or loose installation, which may cause the coating to crack from the edge or joint. The actual case of a workshop shows that after 5 years of using polyester spray-coated trays, only local coating peeling occurred at the bolt connection, and it did not spread further.
In order to improve the crack resistance, it is recommended to take a number of improvement measures. In terms of material selection, modified polyester powder (such as adding elastomers) should be given priority; in terms of structural design, rigid connections should be avoided, rubber gaskets should be used to buffer vibration, and the density of support points should be appropriately increased (spacing <= 1.5m); in terms of process control, it is necessary to ensure that the pre-treatment is thorough and the curing parameters meet the standards. In daily maintenance, it is necessary to focus on checking the bolted joints, tray joints and support structure contact surfaces. If cracks are found, they should be polished and cleaned in time and then sprayed.
In general, the spray coating has good crack resistance in general vibration environments, but for long-term high-frequency vibration occasions, it is recommended to choose a galvanized substrate with a polyester spraying solution and meet the mechanical strength requirements of IEC 61537. In extreme vibration environments, an alternative solution of using a metal bare frame with on-site anti-corrosion can be considered. Through systematic material selection, structural optimization and standardized installation, the long-term performance of the spray-coated cable tray in a vibration environment can be effectively improved.