Complete Sauna Board Drying Process Parameters
Sauna boards need to withstand frequent high temperature and humidity changes. The standard production process is kiln drying plus high-temperature heat treatment, with a final moisture content controlled at 6%-12%. This process effectively prevents wood cracking and deformation, and improves moisture resistance and corrosion resistance.
1. Material Selection and Pre-drying Treatment
Common wood materials: Western red cedar, hemlock, spruce.
Matching thickness for different parts:
Wall panel: 8-12mm
Ceiling panel: 10-15mm
Floor panel: 15-20mm
Natural pre-drying: Stack wood in ventilated environment for 2-4 weeks, reduce initial moisture content to 20%-30% to reduce cracking risk during kiln drying.
End sealing: Coat board ends with 0.5-1mm paraffin wax to avoid end cracking.
2. Kiln Drying Process (Core Process)
Target moisture content: 8%-12%. Three-stage drying process for softwood. Initial stage (MC＞30%): Temperature: 50-60℃, Humidity: 80%-90%, Time: 2-3 days Purpose: Avoid wood surface hardening. Middle stage (MC from 30% to 15%): Temperature: 70-80℃, Humidity: 60%-70%, Time: 3-5 days Purpose: Rapid and uniform dehydration. Late stage (MC from 15% to 8%-12%): Temperature: 60-70℃, Humidity: 40%-50%, Time: 2-3 days Add 48h constant temperature balance treatment. Moisture content deviation ≤±2%. Qualified standard: No crack, no deformation, no mildew.3. High Temperature Heat TreatmentTemperature: 180-220℃ with steam protection to prevent burning. Processing time: 2-4 hours. This treatment reorganizes wood internal structure, lowering hygroscopicity and enhancing anti-corrosion and anti-mold performance. Cooling and humidity adjustment: Cool down at 50-70℃ by water spraying, adjust moisture content back to 8%-12%. 4. On-site Balance Before Installation Place finished boards in dry and ventilated area for 24-48 hours for environmental humidity adaptation. Polish all cutting openings after construction, and seal cuts with preservative or wood wax oil to prevent moisture penetration.
