When purchasing adhesives, the viscosity and bonding strength of the adhesive are important reference indicators, but many people are easily confused and fall into the misunderstanding of equating "viscosity" and "bonding strength". This article will briefly analyze adhesive viscosity and adhesive bonding strength, providing a new perspective for everyone to have a deeper understanding of the performance of adhesives.
Viscosity: a key factor in determining fluid fluidity
Viscosity is an important parameter of adhesives. It reflects the internal friction of the fluid when flowing. It is a physical data used to measure the viscosity, which we can obtain through testing. Viscosity is greatly affected by temperature. Generally speaking, as the temperature increases, the distance between liquid molecules increases, the attraction between molecules decreases, and the internal friction decreases, thereby reducing the viscosity, and vice versa. Therefore, adhesives have their own storage temperature.
Viscosity is also a reference value we often use to reflect the thickness of adhesives. Due to different test conditions, test methods, and viscometers, the viscosity values of the same product will also vary. Generally speaking, low-viscosity adhesives are relatively thinner, have better fluidity, are easier to apply, are less dependent on glue coating equipment, and are more suitable for automated production. High-viscosity adhesives are relatively thicker, have greater viscosity, and have better water resistance and high temperature resistance, but are relatively difficult to apply and operate. Therefore, proper viscosity selection is crucial for adhesive application.
Bonding strength: the key factor affecting the bonding effect
Bonding strength, also known as bonding strength, is an important indicator to measure the bonding effect of adhesives. It refers to the stress required to cause damage to the interface between the adhesive and the adherend or its vicinity under the action of external force. It is commonly known as two bondings. The firmness of the bond between objects. Bonding strength can usually be subdivided into shear strength, tensile strength, peel strength and impact strength. It not only depends on the chemical properties and mechanical properties of the adhesive, but also is related to the state of the adhered surface, bonding process, joint form, stress conditions, environment and other factors.
Generally speaking, bonding strength can be improved by increasing the coating thickness of the adhesive, improving the treatment of the adhered surface, and selecting appropriate curing conditions. But it may increase production costs and may even have a negative impact on the environment. Therefore, choosing the right adhesive and using it correctly are crucial to achieving good bonding results.
The viscosity and bonding strength of the adhesive are two crucial performance indicators. There is no direct connection between them, but they have a direct impact on the final bonding effect. Theoretically, there is no fixed value for bonding strength. The actual bonding strength of adherends of the same material varies greatly. Research has found that adhesives such as epoxy resin and polyurethane have significant advantages in terms of viscosity and bonding strength. . Among them, epoxy resin has high strength and durability and is suitable for bonding between various materials; while polyurethane has excellent flexibility and wear resistance and is suitable for occasions with high durability requirements.
In addition, there are significant differences in performance between different brands and models of adhesives. When choosing a suitable adhesive, it is necessary to comprehensively evaluate it based on actual conditions such as production needs, application environment, supplier qualifications, etc., and obtain good results with the correct usage method bonding effect.
