Fibre Classification
Analytical hardware separates solid impurities from pulp suspensions to determine physical cleanliness and batch quality. The pulmac master screen utilizes precise slot geometries to segregate non-fibrous contaminants according to their hydraulic size and stiffness. Each unit applies controlled pressure differentials across the media to force acceptable fibers through the internal openings.
Particles exceeding the slot width remain caught on the upper surface for subsequent recovery and manual evaluation. Laboratory technicians deploy this mechanism to quantify the concentration of shives and debris within a stock sample. Such quantification provides an objective baseline for comparing incoming raw materials against internal purity targets for fine paper or specialty board production.
Process Verification
Standardization within quality control departments relies on the consistent performance of this equipment to validate mechanical cleaning steps. Operational settings including flow rate and consistency adjust the likelihood of particle passage through the screen plates. A higher consistency within the suspension frequently causes matting over the slots, which alters the rejection efficiency of the apparatus.
Operators maintain calibration by checking the alignment of the internal components and ensuring the integrity of the mesh surface under standard pressure cycles. Deviations in the weight of retained debris indicate a shift in the primary refining or cleaning circuits upstream. Accurate results require the sample to mirror the physical condition of the stock during the high speed transit through paper manufacturing machinery.
Contaminant Quantification
Assessment of dirt counts and shive content forms the fundamental outcome of the evaluation procedure conducted with the device. Gravimetric measurement of the collected rejects assigns a concrete value to the level of pulp refinement achieved by the screening plant. This metric helps converters predict the appearance of dark spots or surface defects in finished white boards where aesthetic uniformity dictates market acceptance.
Consistent data from these tests confirms that the process removes rigid plastics and wood bundles before they reach the headbox or the forming wire. Successful sorting removes material that might otherwise cause sheet breaks or surface blemishes during final conversion steps.
