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: Examination of adhesive penetration in modified wood using fluorescence microscopy

Source: ASCSpring 2005 Convention and Exposition : April 17-20, Columbus, OH. [Bethesda, Md. : Adhesive and Sealant Council, 2005]: 10 p.

Author(s)Chandler, Jermal G.; Brandon, Rishawn L.; Frihart, Charles R.

Publication Year: 2005  View PDF »

Category: Journal Articles

Abstract: Adhesive bonding takes place when an adhesive undergoes the conversion from liquid to solid. The liquid properties are needed for the adhesive to fully wet the bonding substance, and the solid properties are needed for the strength required for the union of the final product. The mobility of an adhesive depends heavily on its own physical and chemical properties and those of the wood surface upon which it is being applied. To improve the interaction, wood is often resurfaced prior to bonding to provide a smooth surface with minimal extractives and other debris. Scientists question whether this step is necessary for wood modified by acetylation, which creates a more hydrophobic material. The amount of adhesive penetration into a wood substrate has a direct correlation to the bond quality. Insufficient penetration causes minimal surface contact for chemical bonding or 'mechanical interlocking.' Over-penetration of adhesive will create 'starved‘‘ or dry bond lines. Fluorescence microscopy is an excellent method of examining adhesive penetration into lumens. It is possible for most adhesives to fluoresce either in their natural form (primary or auto-fluorescence) or when treated with chemicals capable of fluorescing (secondary fluorescence), such as added dyes or pigments. Fluorescence microscopy in our study revealed that the degree of penetration was good for both acetylated and unacetylated wood despite the difference in bond durability. In addition. good lumen penetration did not correlate to poor strength previously observed, therefore leading to the conclusion that lumen penetration does not always relate with bond strength or percent wood failure.

Keywords: Gluing, adhesives, Liriodendron tulipifera, fluorescence microscopy, yellow-poplar, bonding, bond strength, acetylated wood, adhesives, penetration, modified wood

File size: 124 kb(s)

This publication is also viewable on Treesearch:  view
RITS Product ID: 16544
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 »