Expert Details

Expert in Polymer and Plastic Rheology, Polymer and Plastics Processing, Plastic Molding Processes

Expert ID: 725031 Canada

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Capillary rheometry has been central to his research efforts in the area of polymer rheology and processing. It has been used many times in his lab to mimic polymer extrusion of various polymers and plastic compounds. Capillary rheometry has been used in his research to analyze the slip flow of polymers, the rheology of polymers and plastics at high shear rates, to address the effects of viscous dissipation and high pressure on viscosity as well as to study polymer formability and processability.

Cold extrusion has been used to study the processing of polytetrafluoro polymer and ultra high molecular weight polyethylene in the form of paste. The fundamentals of such processes have been studied in detail and all critical issues associated with this process have been mastered in his research efforts. Preforming, degassing, cold extrusion of pastes, formability, and drying of the final product have been studied in detail.
Polytetrafluoroethylene (PTFE) paste extrusion has been studied in great detail including preforming, flow, extrusion, drying and sintering. PTFE tube extrusion, wire coating have also been particularly studied. Several publication in the open literature have been produced by his group. ExpertHatzikiriakos is perhaps the top world's expert in the area of PTFE paste extrusion.

The rheology and processing of fluoropolymers (several types) has been studied in capillary extrusion in order to identify the critical conditions for the onset of flow instabilities and wall slip. Typical resins studies were copolymers of tetrafluoroethylene(TFE) and hexafluoropropylene(HFP) and TFE/HFP/PAVE (perfluoro(alkyl vinyl ether) (PAVE) respectively. All flow regimes have been identified and studied in detail. Processing aids for the extrusion and processing of fluoropolymers have been identified that reduce dramatically the pressure drop along the capillary die and eliminate instabilities.

Plastic forming has been studied from many different points of view. These include capillary extrusion, single screw extrusion, parison formation and solidification as well as molding. In all these processes many critical issues exist that contribute to plastic forming. Polymers studied include polyethylenes, polypropylenes, fluoropolymers, PET and PVC.

Plastic molding has been studied in his lab for various polymers including polyethylenes, polypropylenes, fluoropolymers, PET and PVC. In rheology the most critical initial aspect is the formation of a suitable sample. Such samples are formed through compression molding. In such processes, temperature and pressure should be carefully selected as well as the cooling process to avoid detrimental effects such as frozen stresses, weld lines, micro-cracks etc.

Polymer extrusion is the basis for many other polymer processes. In his research the polyethylene extrusion has been studied as single-screw extrusion, twin screw extrusion and capillary extrusion. Extrusion of polyethylene blends has also been studied. A critical parameter in the extrusion of polyethylenes is the use of processing aids and in this area his group has perhaps the best expertise in the world.

Polymer processing includes many fundamental processes such as extrusion, fiber spinning, film blowing, blow moulding, co-extrusion and injection moulding. He has recently edited a book on polymer processing and instabilities, control and understanging. He is also teaching courses and short courses on polymer processing in general and therefore he has mastered all fundamnetal issues associated with polymer processing, instabilities and processing aids. In addition he has mastered the importance of using rheological techniques to understand polymer processing.

Polymer Rheology is central to ExpertHatzikiriakos' research. In his efforts rheology is used as a tool to solve practical problems in polymer processing. In general it is difficult to understand polymer and plastic processing without understanding their rheology. Therefore it is crucial to relate polymer rheology with molecular structure and processability. This is the main philosophy to ExpertHatzikiriakos research. In the area of applied polymer rheology is a world's expert and has consulted with many companies including ExxonMobil, DuPont, Daikin Chevron Phillips etc.

DuPont & de Nemours Co., Wilmington, DE, USA (October 1992-2001)
He was developing processing aids that help plastics processors to increase rate of production in various processes Carborundum, Buffalo, NY, NY (September 1998-December 2002)
He was studying the properties of Boron Nitride (a technologically important material) for potential applications to polymer processingChevron Phillips Chemicals (March 2007- current)
A new technology HDPE could not be processed properly. He is studying ways to enhance processingDuPont (1999-2001), Daikin (2001-2004), Solvay Solexis(2004-2006), Donaldson Co (2006-2007), Tensolite (2007)
He studied the issues and difficulties associated with the paste extrusion of PTFE (an extremely important material technologically).RoofRoc. BC, (May 2000-Sept. 2001)
He developed a slate for roofing applications from completely recycled materials. The company now is commercially producing the slate.


Year Degree Subject Institution
Year: 1991 Degree: PhD Subject: Chemical Engineering Institution: McGill University
Year: 1988 Degree: MASc Subject: Chemical Engineering Institution: U of Toronto
Year: 1984 Degree: Diploma Subject: Chemical Engineering Institution: Aristotlean U of Thessaloniki

Work History

Years Employer Title Department Responsibilities
Years: 1991 to Present Employer: Undisclosed Title: Professor Department: Chemical and Biological Engineering Responsibilities: Research in the area of polymer rheology and processing

International Experience

Years Country / Region Summary
Years: 2004 to 2006 Country / Region: Italy Summary: Consultant for Solvay Solexis
(Milan, Italy)
Paste extrusion of PTFE at high reduction ratio dies
Years: 2005 to 2005 Country / Region: Greece Summary: He was reviewing proposals submitted by Universities. Funding was coming from European Union
Years: 2001 to 2008 Country / Region: USA Summary: All his academic years he is doing most of his research and consulting work with US companies.

Career Accomplishments

Associations / Societies
1. President of the Canadian Society of Rheology 2004-present
2. Society of Rheology 1989-present
3. Applied Rheology Interest Group Society Plastics Engineers 1989-present
4. Polymer Processing Society 1992-present
5. Canadian Society of Chemical Engineers 1992-present
5. Society of Plastics Engineer’s, member 1991-present
6. Secretary of the Hellenic Society of Rheology 2007-present
Licenses / Certifications
PE in Canada
PE in European Union
Professional Appointments
President of the Canadian Society of Rheology
Secretary of the Hellenic Society of Rheology
Awards / Recognition
1. Mason Award of the Canadian Society of Rheology, CSR, 2014
2. Fellow of the Canadian Academy of Engineering, CAE, 2013
3. Best Paper Publication Award in Journal of Rheology (2009-2010), Society of Rheology 2011
4.Future Technology Award, Society of Plastic Engineers, ANTEC’2000
5. Killam Fellowship for Faculty, 1997-98
6. Best Paper in ANTEC’96 in Applied Rheology Interest Group, 1996
7. Best Paper Publication Award in Journal of Rheology (1992-93), Society of Rheology 1994
Publications and Patents Summary
He has 95 journal papers, 54 papers in proceedings, 70 presentations in conferences, 5 patents and 1 book edited in polymer processing instabilities. 90% of the publications are in the area of polymer rheology and processing

Additional Experience

Expert Witness Experience
1. Patent litigation between Exxon Mobil and Dow for three years (1977-1999)
Law firm: Fish and Neave
Signed declarations and provided continuous consulting
2. Consulting of a few hours (less than 5) on black ice formation for an accident
3. Consulting on deterioration and degradation of rubber in commercial mattresses (2 hrs)
4. Translation of declarations from English to Greek for a dispute that took place in a Greek court.
5. Expert witness (Law Firm:Faegre-Baker-Daniels) in patent dispute, W.L. Gore and Associates vs Atrium Medical Corporation (2013)
Training / Seminars
1. Two daily seminars at the Law Firm Fish and Neave (NY) on technical subjects related to polymer rheology and extrusion (area of plastics)
2. Two industrial short courses
3. Over 20 seminars delivered in industry and another 20 at various Universities around the globe.
4. Consulting for many plastics companies including DuPont, Exxon Mobil, Daikin, Chevron Phillips, Avery-Dennison, Tensolite, Donaldson Co and many others

Language Skills

Language Proficiency
English Academic and Research Career in North America since 1997.
Greek Diploma in Chemical Engineering from Aristotlean University of Thessaloniki (Greece)

Fields of Expertise

capillary rheometer, cold extrusion, polytetrafluoroethylene ram extrusion, fluoropolymer processing, plastic forming, plastic molding, polyethylene extrusion, thermoplastic extrusion, polymer extrusion, polymer processing, polymer rheology, slate roof, polyester production, melt extrusion tableting process, medical polymer molding, polymer coextrusion, medical polymer extrusion, polyvinyl chloride extrusion, plastic handling, polyethylene terephthalate extrusion, polyester extrusion, nylon extrusion, fluid compressibility, ethylene-vinyl acetate extrusion, extruded plastic, extrusion, plastic manufacturing, amorphous polymer, polyvinyl resin processing, fluid compression, melt flow, polypropylene extrusion, parison, granular plastic, thermoplastics compounding, elastomer compounding, injection compression molding, polymer grinding, plastics finishing, plastic flow, Newtonian mechanics, intelligent polymer processing, rubber compounding, rubber extrusion, fluid mechanics mathematical modeling, interfacial fluid mechanics, fluid boundary layer, hot extrusion, material curing, fluorocarbon polymer film, chlorotrifluoroethylene, plastic material, rubber molding, plastic profile extrusion, extrusion die, internal fluid mechanics, Bernoulli equation, thermoforming, polymer joining, polymer film production, polymer compounding, plastic welding, plastic injection molding, pipe flow, mechanics, friction, fluid mechanics, fluid dynamics, rubber processing, compression molding, Bernoulli theorem

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