The Testliner grade Polartest is defined as a TL 3, and Ranheim Paper & Board offers its Polartest range all the way from 65 to 400 g/m², with the 100 to 135 g/m² range being the most popular. Ranheim has been making testliner down to 65 g/m² since the early 1980s.
Polarflute, a recycled fluting (Wellenstoff) grade, is also produced on a regular basis, ranging from 90 to 135 g/m².
Nordic Fibre base
Polartest and Polarflute are mainly sold to the corrugating industry in the Nordic markets. The OCC (Old Corrugated Containers) is collected in Norway and Sweden, where the fibre quality is considerably higher than in continental Europe due to greater use of virgin fibres such as Kraftliner and Semi-Chemical Fluting in the corrugated boxes. Tests have proved that long fibre bindings give corrugated boxes with better strength properties when exposed to wet and humid conditions than by using testliner and fluting with “artificially” improved dry strength by using chemicals and starch.
Ranheim is the only recycled based testliner mill in Scandinavia.