Peeling of acrylic polyurethane topcoat films is a common issue during coating, typically caused by improper substrate preparation, insufficient interlayer adhesion, or high humidity during application. Prevention requires addressing multiple factors.
Paint film peeling: Loss of adhesion between the coating and substrate or between layers, causing blistering and flaking. In severe cases, large sections of the coating may peel off entirely, exposing the substrate or underlying layer.
Root Cause Analysis: Inadequate substrate surface preparation (presence of oil, rust, or old coatings); incompatible primer and topcoat leading to poor intercoat adhesion; excessive environmental humidity causing moisture entrapment in the coating; excessive film thickness generating high internal stress; or improper intercoat interval time (too long or too short).
Preventive Measures: Thoroughly clean, dry, and degrease the substrate according to standard procedures. Select a primer compatible with the topcoat to ensure proper intercoat adhesion. Control environmental conditions during application; avoid high-humidity environments. Apply each coat within the specified thickness range to prevent excessive buildup. Adhere strictly to the recommended intercoat drying times as outlined in the product instructions.
Remedy: For coatings that have already peeled, remove all loose material, re-prepare the surface, and repaint using the correct application process.
CASUL provides a comprehensive support system and technical guidance to ensure stable, reliable coating quality and prevent issues such as paint film peeling.