Polyurethane Soft Touch Film Selection for Folding Cartons
Polyurethane soft-touch films provide superior scratch resistance and score fold integrity compared to BOPP but require higher temperature control and lower web yields.
Deinking Efficiency
Separation Metric
Chemical extraction of inks and coatings from recovered paper stock determines the viability of using recycled fibers in high-grade graphic paper production. This ratio, measured as deinking efficiency, indicates the percentage of ink removed during the pulping, flotation, and washing stages of recycling. Higher efficiency numbers ensure that the resulting pulp meets the brightness requirements for printing and writing grades.
If the deinking efficiency remains low, the secondary fibers can only be diverted into lower-value products such as industrial packaging or corrugating medium.
Process Mechanism
Separation occurs through a combination of mechanical agitation, surfactant chemistry, and air flotation. Surfactants bind to the released ink particles, rendering them hydrophobic so they attach to rising air bubbles in the flotation cell. These bubbles carry the ink to the surface where skimming devices remove the foam.
High deinking efficiency relies on the correct chemical balance to detach the ink from the cellulose without degrading the fiber strength.
Industrial Assessment
Measuring the brightness of handsheets made before and after the flotation process provides a direct calculation of the removal rate. Multi-wavelength spectrophotometer testing allows mills to track the deinking efficiency continuously. Maintaining high efficiency prevents the accumulation of sticky contaminants and residual ink spots in the finished sheet.