Adhesive Joints Under The Magnetic Microscope
Over the next two years, the newly established NMRBond research project at the SKZ plastics centre will be working intensively on the non-destructive testing of several different adhesive joints. For this purpose, the researchers will be using nuclear magnetic resonance spectroscopy (NMR). The process allows the inspection of adhesively bonded components in a short amount of time and is suited for online process control.
The role of adhesives in industrial applications is beginning to grow increasingly important. "The increasing demand for lightweight construction solutions and the continuous improvement of adhesives are the driving forces behind this development. Although previous methods used to inspect adhesive joints offer reliable results, they can only be used randomly and are often destructive," explains SKZ researcher Norbert Halmen. NMR measuring systems with single-sided access to samples could be used for the non-destructive testing of adhesive joints. Thanks to their special design, they enable the curing kinetics of adhesives in adhesive joints to be measured through the bonded component (without touching it) and during the process.
Test methods - from development to application
In its NMRBond research project, which runs from March 3, 2019, to February 28, 2021, the SKZ is pursuing the goal of using unilateral NMR for the non-destructive testing of adhesive joints. In this process, adhesive bonds with classic two-component adhesives as well as with moisture- and UV-curing one-component adhesives will be considered. Various commonly used measurement methods serve as references. In addition, the influences of different pretreatment methods as well as the adhesive and magnet temperatures themselves on the NMR measurements will be investigated. In the end, this should result in a useful correlation of NMR measurements with relevant parameters, such as strength. The aim is to demonstrate a non-destructive testing method that can accompany an adhesive from development to application.
Any interested companies are invited to contact the SKZ to find out more about this project.