Mechanical Pulp Core Bulk Retention during Shoe Press Dewatering Operations
Core bulk retention during shoe press dewatering requires asymmetric pressure profiles and controlled temperature to prevent mechanical pulp lumen collapse.
Extended Nip Pressing
Contact Duration
A mechanical dewatering method utilizes a widened contact area between a shoe and a backing roll to remove water from a moving fibre web. Through the use of extended nip pressing, the machine applies pressure over a longer distance than a traditional roll press. This increased residence time allows for efficient water removal without requiring high peak pressures that might crush the fibres.
Fibre Preservation
The hydraulic forces acting within the web stay lower because the press load is spread across a larger surface. During the operation of extended nip pressing, the moisture moves steadily into the press felt without disrupting the internal structure of the paper. Such gentleness preserves the bulk and stiffness of the board.
High-quality packaging grades benefit from this technology. Such technology allows mills to achieve higher dryness levels before the drying section. This improvement in dryness reduces the thermal energy required for final evaporation.
Production Efficiency
Energy consumption drops when the web enters the drying cylinders at a lower moisture content. The resulting sheet displays superior strength properties compared to those produced on conventional presses. Machines equipped with this technology run faster while maintaining the structural requirements of heavy grammage stocks.