How to improve flexibility in adhesives?
Last update on Jun 13, 2025
Flexibility in adhesives pertains to their capacity to bend and stretch under stress. An adhesive with a high elongation at break is considered highly flexible. Such adhesives are effective in distributing peel and shear stresses over a wider area, enhancing joint efficiency.
Flexible adhesives are indispensable across various industries, especially where moving parts and components need to be bonded without mechanical fasteners. Additionally, they are compatible with a wide range of substrate materials. This ensures sag-resistant joints, which is crucial for designs where aesthetics are important.
Why is flexibility so important for adhesives?
Adhesive strength, on one hand, holds the substrates in place, while flexibility helps maintain the strength when exposed to shock or vibrations. Flexible adhesives can spread the tension along their surface area. They absorb energy rather than transfer it to the substrate(s)1.
Henkel1 quotes the benefits of flexible adhesives as follows:
Versatile products suitable for various applications
High strength and elasticity
Broad-spectrum adhesion
UV and weathering resistance
Suitable for a wide range of substrate materials
Options include compliance with the electrical safety standard
Perfect for bonding materials with varying coefficients of thermal expansion, as adhesives can accommodate the resulting movement
Liquid flexible adhesives can be robotically dispensed for automated assembly lines
Formulation strategies
- Besley. (n.d.). Strength v Flexibility; What is more important in an adhesive?. Forgeway.
- (n.d.). Industrial adhesives. Henkel.
- (n.d.). Flexible Adhesive. ScienceDirect.
- Besley. (n.d.). Decoding Adhesive Terminology: Analysing the Difference Between Toughened, Flexible, and Rigid Adhesives. Forgeway.
- Elliott. (2020). What is flexible flooring adhesive?. Ambience Hardwood Flooring.
- (2017). Plasticizer use in Adhesives and Sealants. Chemceed.