Extensional flows dominate many polymer processes, including blow molding, film blowing, fiber spinning, thermoforming and many others. The rheology of polymeric materials under extensional flows can differ significantly from shear flows and it is important to understand this in order to optimize both materials and processes. In this webinar, we will:
- Introduce examples of extensional flows in polymer processing
- Define the three types of extension and the nomenclature used to describe them
- Introduce the material behaviors seen in extension and how they relate to polymer architecture
- Describe methods for measuring extensional rheology in the laboratory
- Show example measurements and provide tips to avoid errors and artifacts
- Present a case study of thermoforming polystyrene, high impact polystyrene, and a blend of the two