Judging Doctor Blade Wear and Timely Replacement to Reduce Production Losses

Blade wear is a common issue in paper mills, and delayed replacement can severely affect production. Immediate replacement is required when obvious scratches appear on the paper surface, cleaning is incomplete with residues, a large amount of lint adheres to the roll surface, or the doctor blade edge is chipped or dull. Polyurethane blades normally need replacement every 1–3 months, while alloy blades can last 6–12 months with regular regrinding. Daily inspections should focus on blade wear conditions. A replacement log should be established and spare parts stocked in advance to avoid sudden shutdowns due to blade failure, reduce output losses, prevent roll surface damage from worn blades, and lower equipment maintenance costs.