Dispersion barrier coating of high-density base papers.

High-density papers are mode of extensively refined chemical pulp. With their scaled pores and layered structure, they offer interesting possibilities as a packaging material. High-density papers can be coated with aqueous barrier dispersions and polymer melts to produce a material with very low gas transmission rates. Refining and calendering affect the sheet structure, principally by changing the pore size distribution (as measured by the mercury intrusion method) and increasing the barrier properties. Dispersion coating can be applied with various techniques commonly used in pigment coating and converting. The results of this study demonstrate that the properties of these coated papers can be affected both by pre- and postcalendering. The precise effects depend on the basestock properties, coating composition, and coating method. Application : shows how coating and calendering variables can affect the barrier properties of high-density papers.