OLF: Highly Impregnated Films for On-Line Lamination in Continuous Board Presses, 1995 European Polymers, Laminations and Coatings Proceedings

Ali Vahlhaus

Impregnated Papers

Over the past three years, various paper based overlays have been trialed for on-line lamination in continuous board presses. The tremendous pressure (27-35 Kp/cm 2 ) and heat exposure (190°) seemed to make it impossible to provide for a high quality finish.

Papers with a relatively low resin content, though being sufficiently permeable, are lacking stability. Their overlaying topcoat is pushed into the surfacing material during lamination, thus leaving the finished product with an uneven surface and gloss grade.

Highly impregnated papers, though having sufficient stability, are lacking permeability. Hence, the evaporating water content of the substrate (8- 11%) causes a laminated panel to explode when coming out of the press.

Three years of continuous development in our laboratories and on a BISON Hydro Dyn at "Turolense de Tableros (Mostoles)" in Spain resulted in a highly impregnated and permeable film for on-line lamination in continuous board presses; The so-called OLF.