According to medical guidelines, an adhesive must be strong enough to withstand at least 1-2 pounds of frictional force. However, current medical practices may subject the adhesive bond to a maximum of 3 pounds of frictional force. The adhesives are applied to mostly flat surfaces that are free of course hair, which consequently minimizes the friction. In addition to strength, another critical property is the glue's durability. The glue must be durable enough to stay firmly adhered to the surface for up to 5 days.
Peel testing produces information used in determining the adhesive's durability.
In peel testing the force is applied at an angle simulating the removal of the adhesive material. Peel testing can determine the frictional force present from the adhesive bond. The tensile testing of guar gum, dextrin, and the polyacrylates has begun. The results of these tests will be used to determine which of the carbohydrate-based hydrogel adhesives is best suited for the different medical applications. Once this data is complied, the strengths of protein-based materials will be tested using the same procedure.