The headbox in pulp board production performs several essential functions:

1. Stock Distribution: Ensures even distribution of pulp suspension across the full width of the forming section for uniform sheet formation.

2. Pressure Control: Maintains precise pressure to achieve consistent basis weight and thickness throughout the board production.

3. Velocity Regulation: Controls the stock jet velocity to match the wire speed, crucial for proper web formation and fiber orientation.

4. Layer Management: In multi-ply boards, each headbox precisely controls individual layers for optimized board structure.

5. Consistency Control: Maintains uniform fiber consistency through turbulence control elements to prevent fiber flocculation.

6. Profile Adjustment: Equipped with profiling systems to maintain cross-directional uniformity of basis weight and thickness.

7. Flow Straightening: Uses advanced flow straighteners to eliminate turbulence and ensure stable stock delivery.

8. Drainage Optimization: Controls stock jet geometry to optimize initial drainage characteristics.

9. Strength Development: Promotes proper fiber alignment and bonding through controlled turbulence.

10. Quality Assurance: Provides stable operation to minimize defects like streaks or uneven formation.

These functions are crucial for producing high-quality pulp boards with consistent physical properties and surface characteristics. The headbox design must accommodate the higher basis weights typical of board grades while maintaining excellent formation quality.