Emulsion Polymer Isocyanates as Wood Adhesive: A Review

Emulsion Polymer Isocyanate (EPI) adhesives were introduced in the Japanese market for gluing of wood-based products approximately 30 years ago. The water-based emulsion adhesives with isocyanate as crosslinker are used in many parts of the world for production of different types of wood-based products such as: solid wood panels of different types, parquet, window frames, furniture parts, plywood, finger joints and load-bearing constructions like glulam beams and I-beams. The curing characteristics of EPI adhesives are quite complex and include film formation of the emulsion adhesive as well as chemical reactions of the highly reactive isocyanate towards water, hydroxy-, amines- and carboxy-groups. The advantages obtained by the use of EPI adhesives are fast setting speed, cold curing, light colored glueline, low creep of the glueline and high moisture resistance. (C) Koninklijke Brill NV, Leiden, 2010