Accession Number : ADP002439

Title :   Bonding by Surface Reaction,


Personal Author(s) : Johns,W. E.

Report Date : 25 SEP 1980

Pagination or Media Count : 7

Abstract : This paper reports on the continuing research in the area of the chemical bonding of wood. Chemical bonding is a technique which actively attempts to chemically involve the surface of wood in the joint formation process. In the research being reported here, an attempt has been made to improve overall board properties while, at the same time, making the whole process more practical from a large scale application point of view. Accordingly, a 50% solution of nitric acid was applied to green Douglas-fir ring-cut flakes and, after some period of time, dried in a laboratory drier. The variables considered in this research included acid assembly time before drying, time between drying and application of the (same) interphase mixture, and total assembly time. Board properties determined included internal bond (IB), modulus of rupture (MOR), modulus of elasticity (MOE), and wet MOR. Results show that there is a substantial improvement in the board properties when compared to boards made with the initially reported technique. Boards made with drying after acid treatment, when compared to control values, showed a 55% improvement in IB, 8% improvement in MOE, 10% improvement in wet MOR, and a 10% improvement in dynamic MOE, with no change in MOR. The effects of the various assembly times, as well as the statistical implications of this research, are discussed.

Descriptors :   *Wood, *Chemical bonds, *Bonding, Nitric acid, Surface reactions, Modulus of elasticity, Statistical analysis, Analysis of variance, Adhesives, Composite materials, Industrial production, Symposia

Distribution Statement : APPROVED FOR PUBLIC RELEASE