Cristina Coelho

F. D. Magalhães

Jorge Manuel Santos Silva Martins

João Ferra

João Pereira

Luísa Carvalho

Repositório Aberto da Universidade do Porto

CLBA2012  8 e 9 de novembroRio de Janeiro, BrasilAssociação Brasileira de Adesão e Adesivos - ABAAAssociação Portuguesa de Adesão e Adesivos - APAAhttp://clba.cefet-rj.brAdhesive bond strength development evaluation using ABES in different lignocellulosic materialsJ.M.Martins1,4, J. Pereira1,2, C. Coelho1,4, J. Ferra3, F.D. Magalhães1, L.H. Carvalho1,4 1LEPAE, Universidade do Porto, Faculdade de Engenharia, 4200-465, Porto, Portugal.2Associação Rede de Competências em Polímeros, 4200-465, Porto, Portugal.3EuroResinas – Indústrias Químicas, S.A., 7520-064, Sines, Portugal4DEMad, Instituto Politécnico de Viseu, 3504-510, Viseu, PortugalAdhesion phenomena are  involved  in  several  industrial  processes  found in  the  wood industry,  such as the manufacturing of wood-based panels,  cork composites  and high pressure laminates, as well as in the surfacing of wood-based panels with wood veneer, impregnated paper or high pressure laminate. Portuguese companies are both the largest worldwide producers of cork composites and one of the most important players in the wood  based  panels  sectors.  The  bonding  process  with  thermosetting  resins,  usually carried out in a hot-press, is quite complex as it involves simultaneous and coupled heat and  mass  transfer,  adhesive  polymerization  and  complex  mechanical  and  rheological behaviors  [1],  [2].  The dynamics  of  adhesive  curing  and bond strength  development during  the  hot-pressing  process  affects  production  speed,  energy  consumption  and product quality. The optimization of those industrial processes has been carried out so far based on trial and error. Therefore, the development of predictive models that properly describe the adhesive curing process is important to improve product quality and long-term performance.  ABES equipment  (Automated Bonding Evaluation System)  [3] has already shown to be an excellent  tool for evaluating the bonding performance of UF adhesives  [4,5,6].  This  paper  presents  a  new application  for  ABES,  which  has  been developed for determining the rate of strength development of adhesives during cure on wood lap shear joints. This equipment provides a quantitative means of understanding the dynamics of bond strength development under highly controlled conditions. It allows for accurate control of bonding pressure, platen temperature,  and bonding dwell time and good  alignment  of  the  lap  shear  samples.  To  explore  the  reactivity  of  the  different combinations (adhesive-cork, impregnate paper-wood and laminate-wood), a new sample configuration  and  a  new  kinetic  model  are  proposed.  Isothermal  bond  strength development was plotted as a function of time for several platen temperatures and the kinetic parameters were computed from these plot families, for each type of adhesive and combinations. [1] L. Carvalho, in Core Document of COST E34 “Bonding of Timber”, Lignovisionen issue 18, p.197 (Universität für Bodenkultur, Wien, 2008).[2] M. Sernek and M. Dunky, in “Wood-based Panels: An Introduction to Specialists”,  p.203,  H.  Thoemen,  M.  Irle  and  M.  Sernek,  eds.  (Brunel  University  Press,  London, England, 2010).[3] J. Ferra, M. Ohlmeyer, A. Mendes, M.R. Costa, L.H. Carvalho and F. Magalhães, Int. J. Adhes. Adhes., 31(3), 127 (2011)[4]  N.  Costa,  J.  Pereira,  J.  Martins,  J.  Ferra,  P.  Cruz,  F.  Magalhães,  A.  Mendes,  L.  Carvalho, Int. J. Adhes. Adhes., 33, 56 (2012)[5] J. Martins, C. Coelho, J. Ferra, P. Cruz, L. Carvalho, Int. Wood Prod. J., 3, 31 (2012)[6] P. Humphrey, US Patent 5176028 (1993)

Adhesive bond strength development evaluation using ABES in different lignocellulosic materials

Abstract

Similar works

Full text

Available Versions

Repositório Aberto da Universidade do Porto