A COMPARISON OF PRIMER COATING AND CALCIUM CARBONATE ADDITION METHODS OFACHIEVING LDPE COATING ADHESION TO CLAY-COATED BOARD

摘要

An LDPE-based pelleted calcium carbonate (CaCO3) concentrate was used to add 30wt.% fine-ground, surfacetreatedmineral to a 5.0 MI, 0.923ρ autoclave-process LDPE homopolymer. This dry blend was extrusion coatedonto flame-treated clay-coated board. Conventional aqueous-based polyethylenimine (PEI) primer coating of theboard was used as the control.The combined flame pretreating of the board plus the addition of 30wt.% CaCO3 to the LDPE coating resin yieldedfiber-tear adhesion equivalent to that achieved with primer coating. This adhesion was achieved without majorchanges in extrusion conditions or web neck in. Calcium carbonate addition reduced coating COF, increased coating surface energy, and in this test allowed the reduction of melt temperature by 5 °C(10 ℉) while still yielding fibertear adhesion.