REMOVAL OF PRINTING INK, STICKIES FROM SECONDARY FIBER:
The purpose of de-inking is to remove the printing inks and other substances like stickies that might affect the paper making process or the final properties of the paper. In a de-inking process the ink should be first detached from the fiber. Flotation technology with high efficiency provides high yield of fibers and simple handling with maximum operating reliability.
PRINCIPLE OF OPERATION:
The Parason De-inking cell consists of number of cells in series with elliptical cross section with a baffle extending over the entire length of separate suspension chamber from the foam collecting chamber. Air (at the atmospheric pressure) and pulp stock to be de-inked is introduced into the cell chamber through injectors. Flow through nozzles generates vacuum which sucks in the necessary process and generates micro turbulence resulting in widely ranging bubble sizes enabling efficient removal of an equally wide range of particles size. This enhances brightness to a high degree and reduces dirt specks and stickies efficiently. The injectors optimize the quantity of the air injected and the size of the bubbles generated.
The pulp stock freed from ink is pumped from the bottom of one cell to next cell. The ink laden foam overflows to the foam chamber with the help of motorised paddle. Flotation process is operated in a continuous mode and helps to remove ink particles efficiently. Since the cells are interconnected by opening only level control system is required for entire flotation machine.
The primary flotation stage ensures highest possible stock purity and the secondary stage optimize flotation yield without any loss of brightness and cleanliness. A De-aerator cyclone removes air from the stock and usable fibers are recovered from the foam.
-Highest possible degree of brightness is achieved
-Improved optical cleanliness in a recovered paper stock
-No sizing restrictions
-Single level control loop operation
-Optimized flotation yield at secondary stage without loss of brightness and cleanliness
-Very low fiber loss in the de-inking process as the foam is treated in a cascade process
-High percentage of ash in reject resulting on low fiber losses.