Fractionation Classification
Hydrodynamic shear stress provides the physical mechanism for isolating specific pulp fractions according to their surface area and structural dimensions. The haindl fractionator separates fibre suspensions by forcing a liquid sample through a series of increasingly fine screens under regulated pressure. High velocity water streams carry the material across these mesh surfaces to prevent clogging during the removal of fine particles and debris.
Smaller components pass through the openings, while longer fibre chains remain trapped on the upper side of the mesh. This differentiation allows technicians to measure the exact ratio of long, medium, and short fibres present in a mechanical pulp sample. Practitioners utilize these precise ratios to predict how the substrate will behave on a high-speed paper machine.
Evaluation Procedure
Calibration of the water flow rate ensures consistent performance across various batches of raw pulp material. Technicians adjust the inlet valve to maintain a steady hydraulic head, which governs the intensity of the separation process. Digital gauges monitor the pressure differential across the mesh screens to prevent fibre matting or screen blinding.
When the process ends, the remaining solids are collected, dried, and weighed to generate a numerical distribution of the input material. Precise documentation of these values informs the management of refining energy consumption and chemical additive requirements during production.
Operational Limitation
Variable pulp consistency introduces potential bias if the sample input density remains outside the calibrated range of the equipment. Excessive concentrations cause fibre aggregation that masks the true length distribution, leading to errors in the reported fraction totals. This tendency requires thorough dilution of the feedstock before introduction to the device.
Accurate results depend entirely on the strict maintenance of flow dynamics throughout the entire duration of the wash cycle.
