Ammonium chloride was
added to the UMF resins as a hardener (1.0%) and hexamethylenetetraamine
(0.2%) was added as a retarder. The target
content of the added UMF resin was 14% on an oven-dry
basis (db). A wax emulsion supplied by Emutech AB, Sweden
(Boardwax B100) was added to the fibre as a conventional
hydrophobic additive.