UF-pMDI Hybrid Resin for Waterproof Particleboards Manufactured at a Shortened Pressing Time

The aim of the study was to determine properties and potential shortening of pressing time of particleboards resinated with urea-formaldehyde (UF) resin thanks to its modification with pMDI (polymeric 4,4’ - methylene diphenyl isocyanate), introduced to the resin at 2.5 – 10 %. Tests showed that strength properties and water resistance of manufactured boards were improved with the increase of the pMDI amount introduced to UF resin. Furthermore, particleboards manufactured at a shortened pressing time were characterized by better mechanical and physical properties than those of reference boards manufactured under identical conditions, resinated with pure UF resin. It should be emphasized that boards, manufactured with a 10 % share of pMDI in the glue mixture, irrespective of their pressing time, were characterized by water resistance measured by the V100 test at the level required by the standard for exterior boards not bearing loads (type P3).