Kraft Paper: Demanding PMC Requirements
Kraft and packaging paper production (80–200 gsm) places extreme demands on paper machine clothing. High basis weight, high filler content, and aggressive chemical environments require specialized fabric solutions.
Forming Fabric Considerations
For heavyweight kraft grades:
- Higher tensile strength requirements (85+ kN/m)
- Coarser drainage channels for high-consistency stock
- Enhanced abrasion resistance for filler handling
Kraft Press Fabric Design
Key requirements:
- High Void Volume: Handle greater water volumes from heavier sheets
- Compaction Resistance: Maintain performance under sustained high nip loads
- Contamination Resistance: Cope with pitch and stickies from recycled furnish
Dryer Fabric Performance
Wide kraft machines (4,000–6,000 mm):
- Flat yarn construction for stability
- Edge reinforcement to prevent tracking issues
- Hydrolysis-resistant treatment for high-temperature sections
Real-World Results
A Brazilian packaging mill upgraded its dryer section fabrics:
- Fabric life: 6 months → 8 months (+33%)
- Annual downtime: 12 days → 7 days (−42%)
- Moisture profile variation: ±2.5% → ±1.0%
Annual savings: $120,000 in fabric and maintenance costs.