Many forces impact on a carton during the long journey from shipping to opening on the customer side. The bond between the box and the adhesive tape, which is essential to prevent the box from opening, is mainly affected by peel and shear forces.
Shear force
Shear forces affect the adhesive bond parallel to the application direction of the tape. Thus, its shear strength describes its ability to resist these forces while staying in place. This strength ensures that a packaging tape safely fixes the flaps of a cardboard box under static or dynamic load. The shear strength of the adhesive provides insight on its cohesive properties.
A distinction is made between static and dynamic shear strength. The latter refers to the load which is necessary to separate the tape and the substrate, whereas the static shear strength indicates the time passing until the tape shears off the substrate while under constant load.
Peel force
Peel forces attack the adhesive bond at an angle greater than 0°. Therefore, the peel strength depicts the tape’s resistance to e.g. peeling it off by hand. This strength is affected by numerous factors such as surface condition, adhesive composition and thickness or removal speed.
Just like the shear strength, the peel strength can also be differentiated: The dynamic peel strength indicates the force, while the static peel strength relates to the time needed for the tape’s removal.
