Different types of adhesives react differently to the possible types of stress.
In general, it can be said that softer adhesives are better able to absorb dynamic tensile loads. Harder adhesives can cope better with shear forces than soft ones. Extreme example: adhesive "honey", where the two surfaces would easily smear. Splitting and peeling forces are combinations of the two load types tensile load and shear load. In contrast, however, here the force is only applied to a small, linear part of the bonded surface. These types of load should be avoided because they can only be poorly absorbed by adhesive tapes.
Surface tension and bondability
Different materials can be bonded differently. The non-stick surface of a frying pan behaves differently from a metal surface with regard to bonding. In this context, one speaks of surface tension (measured in dyn or mN/m). Roughly simplified, this phenomenon can be compared to the magnetic force with which molecules attract each other (polarity of the surface). If the surface tension is low, measures such as plasma or corona pretreatment or a so-called primer (adhesive force promoter) can improve bonding, in some cases considerably. Large-area force application and distribution reduces component stress (unlike screws or rivets, for example).
Advantages of bonding
Fast and economical connection technology
Joining of even very thin materials, thus lighter construction possible
Unlike other joining techniques, the material structure is not affected (no high temperature as with welding, no drilling etc.)
Elastic connection for vibration and oscillation damping
If necessary, electrical insulation between metal parts, avoidance of contact corrosion
Construction freedom for designers is increased, as no visible screw or welded joints are necessary
Compensation of tolerances and unevenness
Sealing by bonding
Types of loading of a bonding