Dr. John Vlachopoulos
J.Vlachopoulos
Professor Emeritus
Department of Chemical Engineering
1280 Main Street West,
Hamilton, ON, L8S 4L7, Canada
Driving directions and map

Office: JHE 250
Voice: +1 (905) 525 9140 extension 24954
email: vlachopj@mcmaster.ca

polymer processing, rheology, extrusion, rotational molding, CAD/CAM methods
Education
  • Dipl. Ing. National Technical University of Athens (1965)
  • M.S. Washington University, St. Louis (1968)
  • D.Sc. Washington University, St. Louis (1969)
  • P.Eng.since 1971 (Ontario, Canada)

Honours and Awards

  • Fred E. Schwab Award for Outstanding Achievements in Education, S.P.E. (Dallas, Texas 2001)
  • Extrusion Division Distinguished Achievement Award, S.P.E. (Chicago, 2004)
  • S. G. Mason Award, Canadian Society Rheology (Hamilton 2007)
  • Bruce Maddock Award of the Extrusion Division of SPE (Las Vegas 2014)
  • Distinguished Peter Benham Lecturer, Queen's University, Belfast, N. Ireland (2000)
  • D. B. Robinson Distinguished Speaker, Univ. of Alberta, Edmonton, AB (2007)
  • Session in his honour at Polymer Processing Society 26th Intern. Conference (PPS-26), (Banff, AB 2010)
  • Politechnika Warzawska, Visiting Professor (Warsaw 2011)
  • Session in his honour at Hellenic Society of Rheology (HSR), 7th International Conference, Iraklion, Crete, Greece (2014)
  • SABIC Lecturer, Univ. of Akron, Akron, OH (2014)
  • Fellow, Canadian Academy of Engineering (FCAE)
  • Fellow, Society of Plastics Engineering (FSPE)
  • Fellow, Chemical Institute of Canada (FCIC)

Positions

  • Sabbatical research leave at IKT, U. Stuttgart 1975 (Stuttgart, Germany)
  • Sabbatical research  leave at CEMEF, ENSMP, 1981-1982, Sophia Antipolis, France
  • Chair, Department of Chemical Engineering, McMaster University (1985-88)
  • Sabbatical research leave at CEMEF, ENSMP, 1988-89, Sophia Antipolis, France
  • President: Polymer Processing Society (PPS) 2005-2007

 


Research Interests

Soon after arriving at McMaster University in 1968, John Vlachopoulos focused the research efforts of his team of graduate students, research staff and postdoctoral fellows on polymer processing and rheology. He formed the Centre for Advanced Polymer Processing and Design (CAPPA-D) in 1987. His former students and coworkers that worked on the various projects are now university professors or occupy important positions in industry in Canada, USA, South America, Europe and Far East. Special emphasis was placed on developing mathematical models and solving problems of industrial relevance and importance, using finite element and finite difference methods. The most important research accomplishments and projects include:

1. EXTRUDATE SWELL and MELT FRACTURE: Relations involving molecular weight distribution and elucidation of the role of molecular disentanglements.

2. CALENDERING. Models with and without the hydrodynamic lubrication approximation involving wall slip and normal stress effects. Prediction of forces, pressures, torques and the existence of vortices in the melt bank.

3. PLASTICATING and REACTIVE EXTRUSION: Models of the entire plasticating single screw extrusion process from hopper to die exit and applications to screw design as well as in simulation of peroxide degradation for the production of controlled rheology PP.

4. DIE EXTRUSION and COEXTRUSION: Simulation of flow through dies for the production of cast film, sheet, blown film, profiles and development of computer assisted methodologies for design of flat, spiral and profile dies using 2-D models of non-Newtonian polymer flow. Study of special problems in multilayer extrusion using 3-D simulations.

5. FOUNTAIN FLOW IN INJECTION MOLDING: First ever published simulation of this phenomenon as well as elucidation of the role of kinematics, shear thinning and viscoelasticity, explanation of the origin of V-shapes and other effects during the cavity filling process.

6. THERMOFORMING: Finite element simulation of polymer sheet inflation involving Hyperelastic and Viscoelastic constitutive equations with and without the membrane approximation.

7. PARTICLE COALESCENCE (SINTERING): Frenkel’s 1945 model, which was applicable to the very early stages of the process, was extended for the first time to full completion and inclusion of viscoelasticity. Experimental verification was carried out in specially developed particle sintering apparatus.

8. ROTATIONAL MOLDING: Development of rheological characterization techniques and observations of the sintering process under a microscope for the determination of rotomoldability of resins. This method is now used in industry for screening of polymer resins for the rotational molding process.

9. BLOWN FILM EXTRUSION: Elucidation of interactions between polymer rheology and the aerodynamics of cooling including the Venturi and Coanda effects. Study of external single and dual orifice external cooling jets and internal bubble cooling (IBC).

10. PLASTIC WOOD COMPOSITES EXTRUSION: First ever published studies of the skin and edge tearing phenomenon that appears as some sort of exaggerated sharkskin. Detailed rheological studies of heavily filled polymers and study of wall slip phenomena.

11. RHEOLOGY OF BIODEGRADABLE POLYMERS: Studies of viscoelastic behaviour, extrudate swell and melt flow instabilities of biodegradable polyesters

The research efforts lead to the development of several software packages which are licensed through a spin-off, POLYDYNAMICS,INC. (www.polydynamics.com). These are used in industry for routine equipment design, process optimization and troubleshooting purposes (in about 500 corporations in 30 countries around the world): POLYCAD 2-D, EXTRUCAD (renamed NEXTRUCAD in 2004), FLATCAD, SPIRALCAD, PROFILECAD, LAYERCAD, T-FORMCAD, CALENDERCAD, RHEOMWD, XTRU-XPERT.

John Vlachopoulos has provided consulting engineering services to several hundred corporations around the world, he is organizer/lecturer of a short course on polymer processing and rheology and frequent lecturer at international conferences in seven languages (English, German, French, Spanish, Greek, Italian and Portuguese.

List of publications.