Why Adhesion and Cohesion Matter

Adhesion and cohesion are two important properties that affect how well an adhesive works. Understanding these terms helps when choosing the right product, preparing surfaces correctly, and ensuring a strong, long-lasting bond.

Adhesion is the ability of an adhesive to stick to a surface or substrate, such as metal, timber, concrete, glass, or plastic. Good adhesion means the adhesive can form a strong connection between two different materials.

Cohesion is the internal strength of the adhesive itself. It refers to how well the adhesive holds together within its own structure once it has cured. An adhesive with high cohesion will resist tearing, splitting, or breaking under stress.

For example, when using a Tec7 adhesive to bond a metal bracket to plywood, both adhesion and cohesion are important. The Tec7 must first adhere properly to both the metal and the plywood surfaces. If the surfaces are dirty, dusty, oily, or wet, the adhesion may fail because the adhesive cannot properly grip the substrate. This is why correct surface preparation — such as cleaning, drying, and removing loose material — is essential.

At the same time, Tec7 products also need strong cohesion so the adhesive itself does not crack, split, or fail under load or movement. One of the key advantages of Tec7 is that it is an MS polymer adhesive, which means it remains flexible after curing while still maintaining high strength. This flexibility allows the adhesive to absorb movement, expansion, contraction, and vibration without becoming brittle or breaking apart.

This is why MS polymer adhesives like Tec7 are widely used in construction, automotive, and industrial applications where their ability to absorb vibration and movement while maintaining strong adhesion and cohesion are essential.

Did You Know?

MS Polymer technology was originally developed in Japan during the late 1970s. Japan’s frequent earthquakes created a demand for construction materials that could remain strong while also allowing movement and flexibility. Traditional rigid sealants often cracked under vibration and structural movement, so MS Polymers were designed as a highly elastic alternative that could absorb stress while maintaining a strong bond. This is one reason why modern MS Polymer adhesives, such as Tec7, are valued for their flexibility, vibration resistance, and long-term durability in construction and industrial applications.

What to Consider When Selecting an Adhesive

When selecting an adhesive, it is important to consider:

• The type of substrate being bonded
• Surface preparation requirements
• Environmental conditions
• Expected movement or vibration
• The adhesive’s adhesion and cohesion properties

These factors are important because different products are designed for different materials, loads, environments, and applications. Considering adhesion, cohesion, compatibility with the substrate, and proper surface preparation helps ensure the bond performs safely and reliably over time.