Fracture energy testing of thick joints with structural wood adhesives

The test method described by Gagliano and Frazier (2001) was used for the measurement of fracture energy of wood adhesives applied in thick joints for on-site assembling or repair of timber structures.Zusammenfassung Die von Gagliano und Frazier (2001) beschriebene Testmethode wurde verwendet um die Bruchenergie von Klebern für Bauholz zu messen, die für breite Verbindungen zur einseitigen Verstärkung oder Restauration von Holzkonstruktionen angewendet wurden.

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Testen der Bruchenergie breiter Klebeverbindungen für Bauholzkleber

     

A delamination test for structural wood adhesives used in thick joints

Subject A test method was developed for the measurement of delamination of structural wood adhesives applied in thick joints. Large differences were observed within a range of 8 commercial epoxy-based products.     

A delamination test for structural wood adhesives used in thick joints

A test method was developed for the measurement of delamination of structural wood adhesives applied in thick joints. Large differences were observed within a range of 8 commercial epoxy-based products.     

The compatibility of structural adhesives with wood

An evaluation procedure, based on simple test methods, was developed in order to assess the compatibility with wood adherents of some new types of structural adhesives.Zusammenfassung Ein Bewertungsprozess wurde aufgrund einfacher Testmethoden entwickelt, um die Kompatibilität einiger neuer Typen von Klebern für Bauholz einzuschätzen.

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Die Kompatibilität von Klebern für Bauholz

     

The compatibility of structural adhesives with wood

An evaluation procedure, based on simple test methods, was developed in order to assess the compatibility with wood adherents of some new types of structural adhesives.     

Self-neutralizing acid-set PF wood adhesives

A method is described for self-neutralization of acid-setting phenol-formaldehyde resins, to prevent acid deterioration on solid wood. Chemical systems which were developed to enable self-neutralization of resins during setting are also described. The application of those systems in the RF-setting of exterior-grade structural finger joints is discussed. These systems may contribute to reduce the consumption of resorcinol glues in the manufacture of weatherproof-glued finger joints.     

Bonding performance of heat treated wood with structural adhesives

Bonding of untreated, intermediate (hydro-thermolysed) and heat treated wood with melamine-urea-formaldehyde (MUF), phenol-resorcinol-formaldehyde (PRF) and polyurethane (PUR) adhesives was studied. An industrial heat treatment process (Plato ^®) was used, which included two separate heat treatment stages and a drying stage in-between. Laminated beams having four lamellas were prepared from untreated and treated timber for mechanical testing of the bond lines. The results of the tests showed that heat treatment affected the shear strength and the delamination of the laminated wood depending on the adhesive system used for bonding. The PUR and MUF adhesives performed in a rather similar way, and better than the PRF adhesive. The shear strength of laminated wood bonded with the waterborne MUF and PRF adhesives decreased for the specimens made of hydro-thermolysed timber and decreased further for the specimens made of fully heat treated timber. The difference in adhesive bond shear strength between untreated, intermediate and fully treated wood was less obvious in the case of the PUR adhesive. Delamination of the PRF bond line decreased drastically for all the specimens made of heat treated timber.     

Lignin-based wood panel adhesives without formaldehyde

Lignin-based wood adhesives prepared without formaldehyde substituted by non-volatile non-toxic aldehyde, namely glyoxal, were prepared and tested for application to wood panels such as particleboard. The adhesives yielded good IB strength results of the panels, enough to comfortably pass relevant international standard specifications for exterior-grade panels. The adhesives also showed sufficient reactivity to yield panels in press times comparable to those of formaldehyde-based commercial adhesives.     

Tannin-furfuryl alcohol wood panel adhesives without formaldehyde

Tannin-furfuryl alcohol resins reacting under alcaline conditions to minimize self condensation of furfuryl alcohol and force its reaction with tannins have proved to be another alternative for formaldehyde free, environment friendly adhesives from renewable materials.     

Curing conditions effects on the characteristics of thermosetting adhesives-bonded wood joints — Part 1: Substrate influence on TTT and CHT curing diagrams of wood adhesives

p has been slightly modified to take into account the modified CHT diagram. The modified CHT diagram can be used to good effect to describe the behaviour of polycondensation resins when used as wood adhesives during their curing directly in the wood joint.

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One-shot cold-set,urethane adhesives for wet wood

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