Coarse Sanding for Thickness Calibration: First, a 60–80 grit coarse sanding belt is used to rapidly eliminate thickness variations. The material removal depth is controlled to within 0.05 mm to ensure a uniform baseline thickness is achieved.
Fine Sanding: The belt is switched to a 120–180 grit fine sanding belt for gentle polishing. This process removes coarse sanding marks and brings the surface roughness to a standard of Ra ≤ 3.2 µm.
Simultaneous Double-Sided Processing: The upper and lower sanding rollers operate concurrently, allowing for the simultaneous processing of both sides of the board in a single pass. The processing capacity for standard 1220 × 2440 mm boards is 20–30 boards per hour.
Quality Inspection: Inspection criteria include surface flatness (waviness amplitude ≤ 0.1 mm), thickness tolerance (± 0.2 mm), and moisture content (below 40%), ensuring full compliance with the requirements for subsequent veneering processes.