Banner for LabNotes
From Lab Notes
Contact Information
Forest Products Laboratory
One Gifford Pinchot Drive
Madison, WI 53726-2398
Phone: (608) 231-9200
Fax: (608) 231-9592


You are here: FPL Home  / Information Products & Services  / Publications

Requested Product

Title: Wood structure and adhesive bond strength

Source: Characterization of the cellulosic cell wall. Ames, Iowa : Blackwell Pub., 2006: ISBN: 2005016442: pages 241-253.

Author(s)Frihart, Charles R.

Publication Year: 2006  View PDF »

Category: Journal Articles

Abstract: Much of the literature on the bonding of wood and other lignocellulosic materials has concentrated on traditional adhesion theories. This has led to misconceptions because wood is a porous material on both the macroscopic and microscopic levels. A better understanding of wood bonding can be developed by investigating the theories of adhesion and bond strength, taking into consideration the unusual structure of wood. Wood is not uniform in the millimeter, micrometer, and nanometer scales. The interaction of adhesive with wood needs to be considered on these different spatial scales. In addition, emphasis needs to be placed on the stress concentration and dissipation mechanisms that are active in bonded wood. Because most adhesives bond wood sufficiently to give wood failure under dry conditions, the emphasis is on durable bonds, especially those exposed to moisture and/or heat variations. The new hypothesis emphasizes that for durable bonds, the adhesive needs to give during wood expansion or to restrict wood expansion to lower stress in the interphase regions. Among the experiments that support this hypothesis, one study involves the failure mechanism of epoxy wood bonds. Available information indicates that the fracture occurs near the surface within the epoxy layer. A second study is the bonding of acetylated wood with epoxy adhesives. Under wet conditions, acetylated wood expands less than does untreated wood and less stress thus occurs at the interface. In addition, this hypothesis proposes that the primer, hydroxymethylated resorcinol, is not a coupling agent but stabilizes the wood surface.

Keywords: Adhesives, strength, wood, adhesion, failure, epoxy, acetylated, scanning electron microscopy, swelling, bond, durability, wood moisture, epoxy compounds, moisture content, bonding, shrinkage, failures in wood, bond strength, acetylated wood

File size: 335 kb(s)

This publication is also viewable on Treesearch:  view
RITS Product ID: 11967
Current FPL Scientist associated with this product
Frihart, Charles R.
Research Chemist

Additional items that might interest you
View the video celebrating FPL's 100 years of public service in 2010, from the producers of the Greatest Good....view

Research Highlights from FPL....view

Termite Eradication: A search for the Holy Grail.... view

Moisture Management in Residential Construction Series videos...view

Wood Floor Systems in Residential Construction Series videos....view
- FPL's Mission and Strategic Plan -

FPL's mission is to identify and conduct innovative wood and fiber utilization research that contributes to conservation and productivity of the forest resource, thereby sustaining forests, the economy, and quality of life. ... ..more »

- FPL Research Emphasis Areas -
Advanced Composites

As an integral part of the FPL mission, we improve the long-term sustainability of our Nation's forests by creating valuable composite products from biobased materials ... ..more »

Advanced Structures

The FPL has been in the forefront of wood-frame housing research since 1910 and has long been recognized as a world leader in such housing-related areas as engineered wood ... ..more »

Forest Biorefinery

We all know the compelling reasons that the United States needs to reduce its dependence on fossil fuels. Historically, the greatest increases in energy demand have been for transportation fuels ... ..more »


A leader in wood products research for over a century, the FPL is positioning itself to become the lead Federal research facility for the application of nanotechnology in forest products ... more »

Woody Biomass Utilization

Forests in the United States contain a substantial amount of small-diameter, overstocked, and underutilized material.FPL research projects are exploring the potential of the small-diameter ... ..more »