Hopkins, Robert P
Group Leader, Adhesives Applications Group, Research Division, Rohm & Haas Co., Philadelphia, Pa.
Pages: 9 Published: Jan 1953
An effort has been made to obtain specific data on the relationship between the apparent behavior of wood adhesives in permanence tests and the construction of the test specimens. Outdoor exposure and laboratory water-immersion air-dry cycling procedures, with the aid of phenolic or resorcinol resins were used to study this relationship. Brief attention has also been given to recalling the interdependence of construction of plywood test specimens and maximum tensile shear strength, as established by the Forest Products Laboratory years ago.
Quantitative test data obtained show that wood species, nature of the wood construction, and size of the specimen have an important bearing on the apparent permanence of an adhesive. Small test specimens have been found to exhibit greater mechanical stressing on gluelines than relatively larger specimens.
Shortcomings of wood adhesive specifications lacking consideration of the variable of test specimen construction are noted.
The information has led to the conclusion that greater emphasis should be attached to the construction of the test specimens in any efforts to interpret and develop test methods for wood adhesives.
Paper ID: STP44028S