Microcapsules Offer Pressure-Activated, Room-Temperature Adhesion
Researchers have developed microcapsules containing two-component adhesives that activate upon pressing at room temperature, enhancing safety and simplifying bonding processes.
Scientists at the Fraunhofer Institute for Applied Polymer Research (IAP) are pioneering a novel approach to adhesive bonding using microencapsulated two-component systems. This technology aims to streamline industrial assembly and improve occupational safety by containing reactive adhesive components within microscopic capsules. The system remains inactive until pressure is applied, causing the capsules to burst and initiate the cross-linking process, forming a bond at room temperature without the need for additional heating or curing.
The primary challenge in this development lies in the microencapsulation process itself. Two-component adhesives are inherently reactive and can potentially interact with the materials used to create the capsule shell. However, the Fraunhofer IAP team has achieved precise control over the capsule chemistry, ensuring that the adhesive components remain active, are reliably enclosed, and only activate when intentionally pressed.
This microencapsulation method offers significant advantages for industrial applications. Firstly, it reduces direct employee contact with reactive adhesive components, as activation is confined to the joining step. Secondly, the researchers are focusing on isocyanate-free adhesive systems, such as acrylates or epoxies, making the technology suitable for applications where the avoidance of isocyanates is a priority.
In the next phase, these microcapsules will be integrated into sheet-like carrier materials, including textiles or fiber scrims, transforming the adhesive into a manageable interlayer material. This allows for precise placement within components, with the adhesive effect only developing upon application of pressure during the joining process. Potential applications span various industries, including automotive (e.g., battery pack assembly), mechanical engineering, and electronics manufacturing, particularly for complex geometries where traditional adhesive application methods are difficult or costly.
This development in microencapsulated adhesives addresses key challenges in industrial bonding: safety, process simplification, and material compatibility. By enabling room-temperature, pressure-activated curing, it reduces energy requirements and handling risks associated with reactive chemicals. The focus on isocyanate-free systems aligns with broader industry trends toward safer materials. This controlled adhesion method could be significant for complex assembly in sectors like automotive and electronics, and potentially for in-situ manufacturing in space applications where precise, low-energy processes are crucial.
Edited by the news editor with AI from the original report — please refer to the original source.