Characterization of adhesives

Thermomechanical and rheological characterization of adhesives for adhesive selection and failure analysis

The experts at Fraunhofer IFAM provide industrial users with holistic support in the development of a bonded product, i. e. from adhesive selection to the design of the bonded joint and the integration of bonding processes into manufacturing.

This includes an in-depth characterization of adhesives. This is done by means of thermoanalytical methods and application-oriented tests. The aim is to obtain reliable information on the suitability of cured adhesives for subsequent applications on the basis of the relevant material parameters. This requires tests on targeted accelerated adhesive aging by means of climate change tests or media aging. Similarly, the processing properties of adhesives in industrial production, dispensing and application must be taken into account.

Here you will get an impression of the aspects and – also digital – procedures we consider in the characterization of adhesives and bonded joints. We will be happy to advise you on your individual question.

Adhesive selection and qualification


Finding a suitable adhesive is a far-reaching task due to the variety of materials and the requirements resulting from the customer-specific application. In addition to mechanical load transmission, there are further requirements, e. g. medial loads, leak tightness, electrical conductivity, thermal conductivity or damping. In each case, a holistic view of the overall process – from design to surface pretreatment to integration into the relevant production – must be taken.

The experts at Fraunhofer IFAM support the customer in this task in an absolutely neutral manner and independently of the adhesive manufacturer. This support is concrete and consists not only of a neutral market overview in the selection phase. If the customer so wishes, it also includes the targeted qualification of the proposed adhesives by means of thermomechanical analysis and mechanical tests. Fraunhofer IFAM has access to all common test methods, surface modification methods, and a large number of special methods. The problem to be solved is placed in the hands of an interacting team of experienced specialists and, based on the experience gained from thousands of projects, a suitable, safe, individual, and manufacturer-independent solution is usually found.

Thermal analysis and rheology 


The analysis of adhesives and the bonded joints produced with them is of great importance in the development of new bonded joints and in the setup of specific dispensing processes and application processes, but also in quality assurance and damage analysis.

In the phase of selecting suitable adhesives or potting compounds for the respective new product development, Fraunhofer IFAM offers the customer the determination of material data by means of thermal analysis and rheology, which go far beyond the information given in the data sheets of the material manufacturers and thus enable an objective comparison of the products. In the context of qualifying adhesives for a specific application, the analytical methods listed can thus help to greatly limit the number of necessary component prototypes in advance of a new product development.

The quality of the final product depends on the correct selection of the analysis methods and the problem-specific interpretation of the analysis data by the experts at Fraunhofer IFAM.

Analysis and characterization for damage analysis


Analysis and characterization are just as essential for the qualification of adhesives for specific processes as they are for damage analysis. In order to be able to provide relevant answers for the respective problem, it is first of all essential to select and carry out the right methods. Based on the data obtained, it is then equally important to link the analysis data in a meaningful way. The researchers at Fraunhofer IFAM also evaluate them with the help of their extensive expertise in adhesives, reactive polymers, and their applications.

Adhesive aging


In order to ensure the safety in use of an adhesive bond, the requirements with regard to the required resistance of the bond must be determined. Both the type and the extent of the stress must be determined. If high stresses and extensive requirements for the safety in use of the bonded joint coincide, an aging prediction using accelerated aging is recommended.

In addition to the standardized procedures listed below, Fraunhofer IFAM also offers the development and implementation of individual, requirement-specific aging procedures. In this case, a high level of information on the aging process can be obtained at reasonable cost, particularly when the different stresses are combined, e.g. UV irradiation with simultaneous temperature change.