Adhesive selection and characterization

The requirements for the adhesive and the bond are as different as the manufacturing processes involving adhesive bonding technology are diverse. If you are looking for a suitable adhesive for your production process, independently of the manufacturer, or if you are already working with a particular adhesive and would like to test its specific properties, the Fraunhofer IFAM is the right partner for you. The experts at the Fraunhofer IFAM are specialized in analyzing and determining the processing and end properties of a wide range of adhesives.

 

Holistic consideration of the adhesive bonding process

The bonding process and the conditions to which the production is subject in the further course must be recorded holistically in a requirements profile at the beginning of the process in order to find the best possible bonding solution. Based on these requirements, a selection of suitable adhesive classes can then be made in principle, which come into question for the planned production. For this purpose, we conduct extensive research in the internal Fraunhofer IFAM database and on the market.

We have a wide range of characterization methods for qualifying adhesives in order to compare adhesives with each other and to test their suitability for a process – even and especially if your process is still under development. For example, the flow behavior of the adhesives can be determined by rheological characterization, but it is also essential to determine the mechanical properties of the adhesives in order to determine the final properties. This is because these characteristic values make it possible to favor adhesive systems at an early stage, without the need for real components to be available. The Fraunhofer IFAM provides support in selecting the right adhesive for each individual bonding application or manufacturing process.

For testing the adhesion of adhesives, we not only offer methods such as tensile shear tests or compression shear tests, but can also carry out individual project-specific adhesion tests on the real components and thus on the original surface (condition) of the adherends.

 

Weathering has an impact on the bond

Depending on where and how the product is to be used, additional climate change tests and climate exposure are recommended in accordance with the standards of a wide range of industries, for example a test according to PV1200, which is common in the automotive industry. This ensures that the bond is resistant under the respective weather conditions.

 

In the case of damage, the adhesive and the adhesive bonding process must be analyzed

If damage has occurred, our employees can find out how the damage was caused and which property may make the adhesive unsuitable for the manufacturing process or application. To this end, we offer an inspection of the production facility and a complete analysis of the adhesive bonding process or damaged component. If necessary, it may be advisable to change to a different adhesive - here, too, Fraunhofer IFAM provides support. If required, we can also provide expert reports and statements that can be legally verified.

The parameters that can be considered very closely in our company are various. These include:

• Coefficient of thermal expansion
• Glass transition temperature
• E-modulus
• Storage modulus
• Loss modulus
• Curing kinetics
• Pot life
• Viscosity
• Shore hardness
• Coefficient of linear thermal expansion
• Tensile shear strength
• Roller peel strength
• Filler content
• Curing shrinkage

These parameters can be checked with a special selection of procedures that we can perform:

• Thermogravimetric analysis (TGA)
• Dielectric analysis (DEA)
• Thermal analysis and rheology for characterization (analysis and qualification)
• Testing of mechanical properties adapted to customer specific component
• Differential scanning calorimetry (DSC)
• Dynamic Mechanical Analysis (DMA)
• Rheometer (capillary, extensional, rotational)
• Thermomechanical Analysis (TMA)
• Surface analysis (XPS, TOF-SIM, REM, EDX etc.)

 

Debonding can be ensured by knowing the adhesive properties

The experts at Fraunhofer IFAM use their many years of experience in the field of adhesive selection, characterization, and qualification to ensure that it is possible to remove an adhesive bond and subsequently recycle the materials used. Our knowledge in the field of determining the processing and final properties of an adhesive is also essential for this.