Saving resources and improving quality


Melt quality is the ultimate standard in the extrusion process and can be assessed by constantly and reliably monitoring the melt process. As a world first, the Leistritz Elongational Rheometer empowers you to analyze not only shear viscosity, but also  elongational viscosity in a single step and in real time. This delivers immediate insight into even the slightest deviations in extrusion quality. The bottom line is: this assists you in maintaining premium quality and avoiding waste at the same time.

Extrusion product quality is ultimately determined by melt quality. Even the slightest deviations in temperature, material mixture or feed have direct impact on the end product quality. Thus it is paramount to maintain an unbroken high level of melt quality. To do so, reliable and comprehensive data in real time are paramount.

This is exactly what the Leistritz Elongational Rheometer offers. It provides sound data on elongational and shear viscosity without delay or interruptions in the extrusion process – your lever in maintaining quality and saving resources.

Find the right balance between quality and efficiency in resource management

Plastics extrusion has established itself as the major production process in film production, compounding, recycling, research and development.

As diverse as they may be, extrusion processes share one factor: they require constant inline quality monitoring. This lacking, production output may suffer from fluctuations that lead to costly material waste.

The most reliable and safest method to control this parameter is to access reliable and inline data on melt quality in real time.

Melt viscosity is a prime measure of melt quality, as are temperature and melt density. Controlling viscosity is, in consequence, an important quality lever. Research shows that melt viscosity dominates as a parameter for melt quality. This is where rheological data come in to determine the quality of constant quality, verifying quality and giving your the leverage to optimize your production process. The best way to achieve this, is to monitor shear and elongational viscosity in real time.

While real-time monitoring of shear viscosity in the extrusion process counts as an industry standard today, however, elongational viscosity was limited to laboratory analysis up until now. This created a time lag. The immediate impact on the running production line is, that a sudden drop in quality would remain unnoticed, the quality alarm activated too late to avoid waste and time loss. The longer the time lapse, the higher the loss in quality and the higher the waste cost incurred.

These are the benefits of the Leistritz Elongational Rheometer at a glance

  • Inline viscosity analysis eliminates the need for laboratory analysis, reduces laboratory costs and minimizes time loss, effort and hassle.
  • Real time analysis delivers data on melt quality with immediate insight on quality fluctuations and helping you improve product quality.
  • Inline data provide the input you need to qualify and professionalize settings in your production line – fine-tuning material feed and machine power settings.
  • Instead of waiting for laboratory data, you access all data in real time minimizing reaction times between detection of quality deviation and reaction. Again, this saves time, money and resources.
  • Improving resources efficiency not only lowers costs, it also reduces material and energy consumption. This pays into the account for sustainable development, environmental conservation and emission-neutral production processes.

This is where the new Leistritz Elongational Rheometer defines its innovative position. It is a world first in providing data on elongational viscosity in real time.

Solid real-time data with the Leistritz Elongational Rheometer

This is made possible by a new, patented hyperbolic slotted die. It comprises an intake and outflow section plus two transition zones. Initially a melt sample is extracted from the extrusion line and diverted into the rheometer. The hyperbolic geometry of the slotted die creates a constant expansion flow, not possible up until now. The die geometry also prevents subsequent expansion, thus avoiding pressure swirls and dead areas in the flow channel. After analysis, the discharged material can be returned to the extruder without material loss.

The hyperbolic slot die provides measurement data on shear viscosity (shear rates from 10 to 10,000 s-1) as well as elongational viscosity (elongation rates from 5 to 75 s-1) in the running process. The exact measuring data range can be set by the user in advance.

The rheometer also provides IV values and shows the melt-flow index.

The Leistritz Inline Elongational Rheometer thus provides well-founded real-time data on fluctuations in the processing process, which both sustainably improves quality and saves resources.

In addition, the technology can be integrated into existing extruder and production lines. And this without much effort!

The Elongational Rheometer from Leistritz is a flexible, versatile and practical solution for improving melt and product quality in both production and material development while saving resources.