The use of 1C (component) water-based polyvinyl acetate (WBPVAc) adhesives belonging to D4 class according to EN204/205 (boiling water resistance) in wood joint applications is dramatically increasing versus the well-known traditional 2C glue systems (D3 WBPVAc dispersions + isocyanate or D2 WBPVAc dispersion + inorganic salts). This is mainly due to the improvement of new high performance products’ overall stability from a different perspective, which makes them deployable as ready-to-use solutions, avoiding all the concerns related to crosslinker addition and dispersion pot life. This also limits the user’s operative steps and responsibilities throughout the application process in case of failure.
Nevertheless, most of the recent 1C D4 adhesive technologies proposed are still far from fulfilling the overall requirements of this specific durability class; several limitations such as stability and performances over time, strong or sharp smell mainly due to specific crosslinker’s mechanisms, strong glue line colouring, freeze-thaw instability and fragile wooden joints failures in cold conditions still need to be overcome. Thanks to Vinavil wood adhesive expertise, a new 1C waterborne polyvinyl acetate dispersion fulfilling the D4 durability class requirements has been recently developed. The new Vinavil adhesive satisfies the D4 adhesive requirements, shows an excellent stability with a limited viscosity built over time, excellent rheological behaviour to be applied in different coating conditions, low odour emissions, freeze-thaw stability and outstanding performance usually associated with exterior wood load-bearing glues.
Co-authors: Fabio Chiozza, Fabrizio Bernardini, Filippo Iussi, Marco Cerra, Tito Zanetta