How to Avoid Bubbles in Adhesion Process
In industrial applications, performing a strong and reliable bonding process is crucial for product’s performance and product’s durability. Whether in electronics, medical devices, automotive and/or aerospace, even the tiniest imperfections can lead to major failures. One of the most common yet underestimated issues in bonding process is the presence of bubbles between the two surfaces. These air-trapped pockets compromise the integrity of bonds created between surfaces and weaken the effectiveness of adhesive, which eventually leads to defects in the final product. It is important to know why these air pockets are formed and how one can get rid of them to increase the efficiency of the bonding process.
Impact of Bubbles on Adhesion Performance
When air pockets are trapped within an adhesive layer, they create empty areas that reduce the contact between the adhesive and the surface. This situation results in:
- Weakened Bond Strength: Air pockets reduce the surface area in which the bonding process takes place, leading to weaker bonds that may fail under stress.
- Structural Defects: In high-precision industries such as aerospace and electronics, even minor flaws in the structural integrity of a product can cause catastrophic failures.
- Reduced Conductivity: Air pockets between the surfaces disrupt conductivity (electrical, thermal), leading to inefficiencies and even failures.
- Aesthetic & Functional Issues: In applications where visibility is important, air bubbles create surface imperfections.
How Bubbles Form
The air bubbles can be formed during a bonding process for various reasons beyond user mistakes:
- Air Entrapment: When the adhesive is applied, it is important to ensure proper spreading to avoid any air that can be trapped between the adhesive and the surface.
- Outgassing: Some substrates can release gases during the curing process, which results in the formation of bubbles.
- Viscosity Issues: High-viscosity adhesives are more prone to trapping air.
- Curing Process: A rise in temperature during the curing process can enlarge the size of already existing air bubbles.
How to Avoid Air Bubbles
To achieve the best results, there are several preventive measures to consider:
- Proper Surface Preparation
- Degassing the Adhesive in a Vacuum Chamber
- Controlled Application Techniques
- Optimized Curing Conditions
- Choosing the Correct Adhesive
Conclusion
In conclusion, even the tiniest air bubble can cause the biggest problem and create catastrophic failures in important systems. That’s why it is essential to make sure that there are no air bubbles between the surfaces during the bonding process.