Prepainted RAL9003 Matt Galvanized Steel for fence

Regarding proven on-site remediation strategies for finished color-coated metal sheets that fail the MEK test, process adjustments must be made based on the specific causes of the failure to prevent future batch defects. The specific adjustment and remediation measures, categorized by the cause of failure, are outlined below: Process Adjustments for Remediation The primary reason for MEK test failure is insufficient coating curing. Based on common causes, the corresponding production adjustments are as follows: ‌Substandard Baking Temperature/Sheet Temperature‌ Both excessively high and low sheet temperatures can lead to MEK test failure. Coil temperatures must be monitored regularly; when switching to batches with significantly different specifications, coil temperatures must be precisely re-measured, and furnace temperature settings adjusted according to sheet thickness to ensure the sheet temperature meets coating curing requirements. ‌Inadequate Pre-treatment Cleaning‌ Residual oil or impurities on the substrate surface can impair coating curing and adhesion. It is necessary to optimize the pre-treatment rinsing process, replace cooling water, and improve the squeezing efficiency of the wringer rolls to ensure the substrate surface is clean and free of impurities.