Dr. John Vlachopoulos – Faculty of Engineering
John Vlachopoulos

Dr. John Vlachopoulos

Expertise

Polymer processing and rheology

  • Professor Emeritus

    Chemical Engineering

Overview

Arriving at McMaster University after defending his doctoral dissertation (August 1968), John Vlachopoulos started teaching fluid mechanics, heat transfer, rheology and polymer processing  courses, at both undergraduate and graduate level. He focused the research efforts with his graduate students, research staff and postdoctoral fellows on polymer processing and rheology. He founded and directed  the Centre for Advanced Polymer Processing and Design CAPPA-D (1987-2017). His former graduate students and research coworkers are now university professors or occupy important positions in industry in Canada, USA, Latin America, Europe and the Far East. Special emphasis was placed on rheological characterization of polymers, on developing mathematical models and solving problems of industrial relevance, using finite element and finite difference methods. The most important research accomplishments and projects include:

  1. POLYMER EXTRUSION INSTABILITIES: Relations involving molecular weight distribution and elucidation of the role of molecular disentanglements on extrudate swell and melt fracture phenomena.
  2. SCREW EXTRUSION OF PLASTICS: Models of the entire plasticating single screw extrusion process from hopper to die exit and applications to screw design, as well in simulation of peroxide degradation for the production of controlled rheology PP.
  3. EXTRUSION DIE FLOW SIMULATION AND DESIGN: 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.
  4. 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.
  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 orientation phenomena behind an advancing flow front in cavity filling.
  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. The extended model is currently being used in modeling sintering phenomena in selective laser sintering (SLS) and fused deposition modeling (FDM) by several research groups.
  8. ROTATIONAL MOLDING: Development of rheological characterization techniques and observations of melt densification under a microscope for the determination of rotomoldability of resins including foams.
  9. BLOWN FILM EXTRUSION: Elucidation of interactions between polymer rheology and the aerodynamics of cooling by turbulent impinging air jets, including the Venturi and Coanda effects. Studies of external single and dual orifice cooling jets and internal bubble cooling (IBC).
  10. PLASTIC WOOD COMPOSITES EXTRUSION: First ever published studies of the surface tearing phenomenon that appears as some sort of exaggerated sharkskin. Study of the role of  wall slip.
  11. RHEOLOGY OF COMPOSITES AND RECYCLED PLASTICS: Rheological changes in plastics recycling, rheology of biodegradable polymers, rheology of composites including carbon nanotubes.

JOHN VLACHOPOULOS received his DIPL.-ING. Degree (1965) from the National Tech. Univ of Athens (NTUA), Greece, his M.S. (1968) and D.Sc.(1969) degrees from WASHINGTON UNIV. in St. Louis, Mo. USA working on a NASA/McDonnell-Douglas sponsored project involving high temperature, turbulent air jets. He joined the Department of Chemical Engineering at McMaster University soon after defending his doctoral dissertation (August 1968). He was Assistant Professor of Chemical Engineering (1968-1974), Associate Professor (1974-1979), (Full) Professor (1979 -2007) and Professor Emeritus from 2008 to present. He served as Department Chair for three years (1985-1988). He was on sabbatical research leave at the Institut für Kunststoftechologie (IKT), University of Stuttgart, Germany (6 months,1975), Centre de Mise en Forme des Materiaux (CEMEF), Ecole des Mines de Paris (now PARISTECH), Sophia Antipolis, France (11 months, 1981-82 and 7 months 1988-89).

Since joining McMaster in 1968, he has been doing research on polymer processing and rheology, including plastics extrusion, injection molding, computer aided die flow simulation and design, calendering, thermoforming and rotational molding. He is the author of 140 papers in peer reviewed journals, over 100 publications in conference proceedings and 19 chapters in various books. He has published a textbook entitled “Fundamentals of Fluid Mechanics” 815 pages, Polydynamics Inc, Dundas, ON, Canada (2016) (downloadable from www.researchgate.com) and he is the co-editor of two other books: with J.R. Wagner Jr, “The SPE Guide on Extrusion Technology and Troubleshooting” 439 pages, SPE, Brookfield, CT,USA (2001) and with J.A. Covas, J.F. Agassant, A.C. Diogo, and K. Walters , “Rheological Fundamentals of Polymer Processing” 463 pages, Kluwer, Dordrecht, The Netherlands (1995). Over the years he has served as consultant to several hundred corporations around the world. With his coworkers, he has developed the commercially available POLYCAD®, SPIRALCAD, CALENDERCAD, FLATCAD, PROFILECAD, EXTRUCAD (renamed NEXTRUCAD), LAYERCAD, T-FORMCAD, B-FILMCAD, RHEO-MWD, XTRU-XPERT and CALCUTRUDE software packages, which have been licensed to more than 500 corporations in 30 countries through the company that he founded, POLYDYNAMICS, INC (www.polydynamics.com). He has lectured in 43 countries around the world in seven languages (mostly in English, but also in French, German, Spanish, Greek, a few hours in Italian and two hours in Portuguese).He has presented his 2-4 day short course (usually as the sole lecturer) 77 times, since 1987, to over 2000 polymer professionals from industry, in Canada, USA, Mexico, Venezuela, Brazil, Greece, Italy, Spain, Belgium, Luxembourg, The Netherlands, Germany, Sweden, Czechoslovakia, Sweden, Finland, Japan, Australia and New Zealand. He received from the Society of Plastics Engineers (SPE) the 2001 Fred E. Schwab Education Award at ANTEC in Dallas, Texas and from the Extrusion Division of SPE, the 2004 Distinguished Achievement Award at ANTEC in Chicago and the 2014 Bruce Maddock Award at ANTEC in Las Vegas. He is also the recipient of the Stanley G. Mason Award of the Canadian Society of Rheology (2007) and Fellow of the Canadian Academy of Engineering (FCAE). He was the President of the Polymer Processing Society (PPS) 2005-2007, and member of several other professional associations: PEO (P.Eng., Ontario), CIC-CSChE (Canada), AICHE (USA), SOR (USA), VDI (Germany), HSR (Greece), SPE (USA-international). He is also member of the editorial board of two journals (Advances in Polymer Technology (Wiley), International Polymer Processing, Hanser Publishers) and a book series (Progress in Polymer Processing, Hanser Publishers). He has served as member of several provincial, national and international committees, on research, science, technology and education.

  • DIPL.-ING. Degree from the National Tech. Univ of Athens (NTUA), Greece (1965)
  • M.S. from WASHINGTON UNIV. in St. Louis, Mo. US (1968)
  • D.Sc. from WASHINGTON UNIV. in St. Louis, Mo. US (1969)
  1. Fellow (FCIC), Chemical Institute of Canada (1985)
  2. President, Canadian Rheology Group (now Canadian Society of Rheology (CSR/SCR)) 1986-1988.
  3. Course Director and Lecturer (mostly sole lecturer), International Short Course on Polymer Rheology and Processing (Extrusion) (77 times in 19 countries, 1987—present)
  4. Chair, Organizing Committee, 7th International Conference of the Polymer Processing Society (PPS-7), Hamilton, ON, Canada (over 400 participants from 23 countries)
  5. Peter Benham Distinguished Lecturer, Queen’s University, Belfast, N. Ireland (2000)
  6. Fellow (FSPE), Society of Plastics Engineers (2001)
  7. Fred E. Schwab Education Award for outstanding achievements in plastics education, from the Society of Plastics Engineers (SPE), ANTEC Dallas, Texas, USA (2001).
  8. Distinguished Achievement Award of the Extrusion Division of S.P.E. “in recognition of his contributions to the plastics industry” Chicago, Illinois, USA (2004).
  9. President, Polymer Processing Society (PPS, 2005-2007)
  10. D.B. Robinson Distinguished Speaker, University of Alberta, Edmonton Canada (2007)
  11. S.G. Mason Award for outstanding contributions to rheology, from the Canadian Society of Rheology, Hamilton, Ontario, Canada, (2007).
  12. Honoured with a special symposium during the 26th International Conference of the Pol. Proc. Soc.(PPS-26), in Banff, Alberta, Canada (2010).
  13. Visiting Professor, Warsaw University of Technology (2011)
  14. Bruce Maddock Award, of the Extrusion Division of SPE, for contributions to single screw extrusion fundamentals (SPE ANTEC, Las Vegas, 2014)
  15. SABIC Lectureship Award, University of Akron, Akron, OH, USA (2014)
  16. Fellow (FCAE), Canadian Academy of Engineering (2014)
  17. Conference Honouree, 7th International Meeting of the Hellenic, Society of Rheology, Heraklion, Crete, Greece (2014)

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