Polymer Processing Institute


The Polymer Mixing Study

The PPI Polymer Mixing Study was initiated in 1990 as an industrially sponsored multi-year research program aimed at understanding the fundamental and practical engineering aspects of polymer mixing. The program started under the direction of Professors Costas G. Gogos of Stevens Institute of Technology and Zehev Tadmor of Technion, Israel Institute of Technology. During the course of the study, Prof. Tadmor was appointed President of the Technion. Dr. Gogos served as the sole director of the research program and the technology transfer to industry.

TSMEE: Twin Screw Mixing Element Evaluator

The Polymer Mixing Study was supported by a consortium of industrial organizations whose representatives share biannually the results of the research work in two-day meetings held at PPI. In addition, members of the Mixing Study team often visited the sponsors for in-house, wide-audience discussions of their work. In the past seven years, a growing number of sponsors have come to PPI to conduct proprietary work on their own polymer systems using the mixing element evaluators and the on-line sensors developed in the study.

Industrial Sponsors

The Dow Chemical Co.

Krupp Werner & Pfleiderer Corp.

Eastman Chemical Co.

Dow Corning Corporation

Exxon Chemical Co

Mitsubishi Kasei Corp.

E. I. DuPont de Nemours & Co.

Solutia, Inc.

Japan Steel Works


The Polymer Mixing Study research team consisted of full time research engineers who have extensive experience in experimental and computational methods in polymer processing. The team drew heavily on the compounding and reactive processing expertise and facilities of the Polymer Processing Institute. A number of advanced graduate students complimented the team by performing specific technical tasks. 

The research work consisted of theoretical, computational, and experimental studies using a number of thoroughly characterized single and binary polymer systems in commercial and developmental mixing and processing equipment.

The central objective of the Mixing Study was to generate technology and apply it to improve the industrial practice of compounding non-reactive and reactive polymer systems including blends, alloys, and additives. This objective has been approached through a comprehensive research program focusing on the following: 

a.   Detailed examination of the melting behavior of single-component polymer materials

b.   Mixing behavior and morphologies development in individual mixing elements and sequences of elements

c.   Simulations of complex flows encountered in mixing and 

d.   Development of experimental tools and methods for flow visualization, process monitoring, and sample analysis.

In addition to the two-day biannual meetings, the industrial sponsors received detailed and quantitative information on distributive and dispersive mixing, and morphology of well-characterized polymer/additives and polymer blend systems. Experimental data are being used to perfect mixing simulation algorithms. The source code of these algorithms is being given to the sponsors. Novel on-line sensors for monitoring the degree of mixedness and polyblend morphology have been developed and are also being made available to the sponsors.

The following are some research topics recently addressed by the Polymer Mixing Study:

  • Melting phenomena occurring in twin-screw kneading blocks. The objective of this detailed experimental work is the study of all the phenomena which lead to melting as well as the modeling of the melting process in twin-screw extruders
  • Morphology development, breakup mechanisms, dispersion rates, and stabilization in two component immiscible compatibilized blends. This work has been conducted for a number of rheologically different materials both under melt-melt mixing as well as dissipative mix-melting conditions. Scale-up work has also been performed
  • Dispersion of solid particulates in single-component polymer systems
  • Dispersion of very low viscosity, reactive, and non-reactive liquids in single polymer systems, of interest to the important emerging technology of reactive polymer processing, through which polymer chain modification and functionalization is achieved. These studies also address some of the problems of mixing of additives such as stabilizers, antioxidants, and fire retardants, as well as lubricants


Epilogue:  Due to downturn of the global economy during the past three years (2001-2003), PMS Project was suspended due to lack of external outsourcing fund.  Several members, though, continued to work with PPI ine the utilization of the results obtained during the PMS Project.

For more information, please contact

Dr. Costas G. Gogos
(973) 596-5665