Extensional rheology plays a crucial role in understanding material behavior in processes such as coating, fiber spinning, blow molding, and foam production. Unlike conventional shear rheology, extensional measurements provide key insights into temperature stability, shrinkage, relaxation dynamics, brittleness, and the adhesion or peel strength of films and fibers. This method is particularly valuable for low density polyethylene (LDPE), as extensional rheology is among the most sensitive techniques for detecting long chain branching, a structural feature that strongly influences polymer processability and the mechanical properties of final products. Furthermore, in polymer recycling, where repeated processing can significantly impact melt strength, branching, and extensional behaviour, this characterization technique enables to evaluate more precisely processability and structural evolution of recycled polymers, thereby supporting Certech’s development of more robust recycling and upcycling strategies.
The accessory offers a significant advantage over traditional elongational rheometers:
• Both drums on which the sample is positioned rotate, ensuring the sample remains stationary within the camera’s field of view throughout the deformation process.
• This configuration allows clear visualization at high temperatures (up to +600 °C) and ensures that the correct fixture displacement function is applied, an essential requirement for extracting meaningful and accurate elongational viscosity data.
With this investment, Certech continues to strengthen its expertise in advanced rheological characterization and to support partners with state of the art analytical tools.
Extensional rheology
