1. Adhesive viscosity
       Viscosity is an important parameter of adhesives. It reflects the strength of the interaction between liquid molecules during movement and is a physical data used to measure the viscous force. When fluid flows, the relative motion between adjacent fluid layers creates frictional resistance between the two fluid layers, which is called viscous resistance.
       To put it simply, in adhesives, viscosity is a reference value that reflects whether the adhesive is thin or thick. Generally, the thicker the glue, the slower the fluidity and the greater the viscosity of the adhesive; conversely, the thinner the glue, the faster the fluidity. , correspondingly, indicating that the viscosity of the adhesive is smaller.

2. Bonding strength
       The bonding strength of adhesive, also known as bonding strength, is one of the important indicators for evaluating the quality of adhesives. Bonding strength refers to the stress required to cause damage to the interface between the adhesive in the adhesive part and the adherend or its vicinity under the action of external force. Moreover, according to the stress conditions of the adhesive during use, the bonding strength is usually subdivided into shear strength, tensile strength, peel strength and impact strength.
       The size of the bonding strength not only depends on the adhesive force, the mechanical properties of the adhesive, the nature of the adherend, and the bonding process, but also depends on the joint form, stress conditions (type, size, direction, frequency), environmental factors (temperature) , humidity, pressure, medium) related to test conditions, experimental technology, etc.
       It is worth noting that adhesion is only one of the important factors that determine bonding strength. It and bonding strength are two completely different concepts and cannot be equated.