Prepainted PVDF Wood Grain Steel Coil

Inspection of Substrate Thickness Tolerance The thickness of the substrate directly impacts structural strength and can be verified using the following method: Using a micrometer with an accuracy of 0.01 mm, take measurements at 3 to 5 different points across the sheet. According to the national standard GB/T 12754, the thickness deviation must not exceed ±0.02 mm. Practical Application Requirements: The substrate thickness for roofing panels must be no less than 0.6 mm, and for wall panels, no less than 0.5 mm. Insufficient thickness results in poor panel rigidity, making the material prone to deformation and sagging. Inspection of Appearance and Cut Edge Condition A compliant substrate features a surface that is flat and uniform, free from defects such as pits, rust, or uneven spangle patterns. The cut edges should be neat and free of burrs, with no signs of coating delamination or peeling. Substrates of inferior quality will typically exhibit excessive burrs at the cut edges and peeling of the coating, indicating poor processing quality of the base material.