ABSTRACT
The testing of bulk adhesives is a relatively straightforward procedure. After selecting the surface treatment and the type or class of adhesive that a design requires, an evaluation of the mechanical properties of the adhesive must be made. The torsion shear technique can be used to determine the torsion shear modulus, generate microyield data, and to measure the fracture stress and strain of adhesives. The ability of the torsion shear technique to generate mechanical property data on a wide range of adhesive systems can best be illustrated by presenting typical data from different types of adhesive systems. When machining the specimen, the cutting must be slow enough so that the adhesive will not overheat and change its mechanical properties. Of primary importance in the specimen manufacture is the bonding procedure that must be followed to ensure axiality of the adherends and the accurate measurement of the resulting bond line.
