What Can Affect The Durability Of Adhesives And Sealants?
There’s nothing worse than a product not performing as it should. Not only can it incur unnecessary costs, but it’s equally frustrating knowing it could’ve all been avoided. Within this article I’m going to cover the top 10 factors that affect the durability of adhesives and why said impact occurs.
Temperature
Variations in temperature (extreme highs and extreme lows) can cause embrittlement and discolouration.
Humidity
Introducing moisture into an environment experiencing high/low temperatures hydrolyses the internal polymer backbone of an adhesive. This can turn a stable paste into a liquid, gel or chalk.
Ultraviolet Light
Short UV wavelengths can break down the intermolecular forces within an adhesive. Visible changes can be noticed when UV degradation occurs; this can include colour changes, loss of gloss, chalking, cracking, blistering and embrittlement. All of which can result in reduced performance.
Microbes/Fungi
This may grow around a sealed joint and act as a contaminant. This may cause de-bonding and produce discolouration.
Cleaning Solvents
Heavy use of cleaning solvents can dramatically impact the strength of adhesion. Solvents can diffuse into the adhesive, creating swelling and distortion on the bond line, reducing it’s mechanical properties.
Salty Environments
Salt in the atmosphere does not directly impact the adhesive itself. However, it can induce corrosion on metal substrates, and once corrosion sets onto the bonding site, delamination is inevitable.
(Refer to “Can Corrosion Impact Adhesives” blog).
Acid Deposits
While this may be a rarity, acid rain causes a breakdown in the adhesive, directly affecting the strength and elasticity.
Joint Movement
Thermal expansion and shrinkage on joints can impact service life. If service joints are unevenly stressed, adhesive failure can occur (where the force on the adherend is greater than the forces in the adhesive).
Poor processing
De-bonding will occur if the adherend is prepared insufficiently.
If you have any further questions on how to avoid these issues, or are looking for some non-biased advice, feel free to contact one of our experts using the number above!
