Full definition
A scraper blade assembly mounted at the head (discharge) drum that contacts the belt surface immediately after material discharge, removing residual carryback (adhered material) to keep the return strand clean. Blade materials: molded polyurethane (most common, 75-85 Shore A, self-sharpening wear), tungsten carbide tips (extreme abrasion, for mining), ceramic inserts (long life, aggressive cleaning), and stainless steel (food grade). Mounting: typically a torsion-arm or spring-loaded assembly that maintains constant blade pressure against the belt as the blade wears. Blade angle: 0-15° to belt surface depending on design. Contact pressure: 1-3 lbs per linear inch of belt width. Cleaning efficiency of primary alone: 60-80% carryback removal. Must be compatible with mechanical splices (blade must ride over splice smoothly). Per CEMA 576 and Martin Engineering cleaning guidelines. Brands: Martin, Flexco, ASGCO, Brelko, Slic Stick. Inspect and adjust tension weekly; replace blades when worn to minimum length mark.