* The abstracts are available for each conference contribution when you click on the corresponding title.
July 28, 2009
7:00 – 7:55
Registration
7:55- 8:10
Welcome
CONSTITUTIVE EQUATIONS
(Chairman: Martin Zatloukal)
8:10 – 9:00
Recent Advances in Constitutive Modeling of Polymer Melts
Autors:
Jaroslav Strnadel and Ivan Machač
Affiliation:
University of Pardubice, Institute of Environmental and Chemical Engineering, Faculty of Chemical Technology, Studentská 573, 532 10 Pardubice, Czech Republic
Abstract:
In this contribution, the results of experimental determination of the drag coefficient correction factor for spherical particles moving slowly through a Carreau viscosity model fluid are presented. The experimental values of the correction factor, which were evaluated from measurements
of terminal falling velocity of seventeen types of spherical particles in viscoelastic polymer solutions, are compared with those calculated numerically using a finite elements method. The results obtained confirm that in the case of shear thinning concentrated polymer solutions the viscoelastic effects are only of minor significance. However, in the case of less concentrated high-molecular polymer solutions in polyalkylene glycol Emkarox an evident drag enhancement has been observed.
Keywords: Shear-thinning fluids, Viscoelastic fluids, Drag coefficient, Carreau viscosity model, Deborah number.
PACS: 47, 83.80.Rs, 83.85.Cg
Manfred Wagner | TU Berlin | Germany
9:00 – 9:30
Rheological Characterization and Constitutive Modeling of Two LDPE Melts
Autors:
Víctor Hugo Rolón-Garrido 1), Radek Pivokonsky 2, 3), Petr Filip 2), Martin Zatloukal 3) and Manfred H. Wagner 1)
Affiliations:
1) Chair of Polymer Engineering/Polymer Physics, Berlin Institute of Technology (TU Berlin), Fasanenstrasse 90, D-10623 Berlin, Germany.
2) Institute of Hydrodynamics, Academy of Sciences of the Czech Republic, Pod Patankou 5, 16612 Prague 6, Czech Republic.
3) Polymer Centre, Faculty of Technology, Tomas Bata University in Zlin, TGM 275, Zlin 76272, Czech Republic.
Abstract:
Experimental data of two low-density polyethylene (LDPE) melts at 200°C for both shear flow (transient and steady shear viscosity as well as steady first normal stress coefficient) and elongational flow (transient and steady-state elongational viscosity) as published by Pivokonsky et al. [1] were analyzed by use of the Molecular Stress Function (MSF) model for broadly distributed, randomly branched molecular structures. For quantitative modeling of melt rheology in both types of flow and in a very wide range of deformation rates, only three nonlinear viscoelastic material parameters are needed: While the rotational parameter, a2 , and the structural parameter, β , are found to be equal for the two melts considered, the melts differ in the parameter f2max describing maximum stretch of the polymer chains.
Keywords: Rheology, MSF model, Shear flow, Elongational flow, Strain hardening,
Low-density polyethylene, Polymer melts.
PACS: 83.10.Gr, 83.10.Kn, 83.60.Df, 83.60.Df, 83.80.Sg, 83.85.Rx, 83.85.Jn, 83.85.Lq,
83.60.Fg
Víctor Hugo Rolón-Garrido | TU Berlin | Germany
9:30 – 10:00
Cofee break & Exhibition
NOVEL RHEOLOGICAL TECHNIQUES I
(Chairman: Manfred Wagner)
10:00 – 10:30
High Strain Rate Rheology of Polymer Melts
Autors:
Adrian Kelly, Tim Gough, Ben Whiteside and Phil D. Coates
Affiliation:
IRC in Polymer Engineering, School of Engineering, Design and Technology, University of Bradford, UK, BD7 1DP.
Abstract:
A modified servo electric injection moulding machine has been used in air-shot mode with capillary dies fitted at the nozzle to examine the rheology of a number of commercial polymers at wall shear strain rates of up to 107 s-1. Shear and extensional flow properties were obtained through the use of long and orifice (close to zero land length) dies of the same diameter. A range of polyethylene, polypropylene and polystyrene melts have been characterized; good agreement was found between the three techniques used in the ranges where strain rates overlapped. Shear viscosity of the polymers studied was found to exhibit a plateau above approximately 1×106 s-1. A relationship between the measured high strain rate rheological behaviour and molecular structure was noted, with polymers containing larger side groups reaching the rate independent plateau at lower strain rates than those with simpler structures.
Keywords: Rheometry, High strain rate, Injection moulding.
PACS: 83.60.Fg
Adrian Kelly | University of Bradford | United Kingdom
10:30 – 11:00
Morphology Development in Polymer Blends under Uniaxial Elongation
Autor:
Zdeněk Starý
Affiliation:
Institute of Polymer Materials, Friedrich-Alexander University Erlangen-Nuremberg, Martensstr. 7, 910 58 Erlangen, Germany.
Abstract:
The properties of immiscible polymer blend are distinctively influenced not only by the properties of blends components but also by its phase structure. Therefore, investigation of relationships between deformation and morphology development in polymer blends under elongational deformation is of great interest. In this work the features of the creep elongational experiments and their benefits regarding the morphology development are discussed. Furthermore, the study of deformation of the dispersed droplets during the creep experiments in uncompatibilized and compatibilized polystyrene/linear low-density polyethylene blends is presented.
Keywords: Blends, Morphology, Uniaxial elongation, Rheology, Compatibilization.
PACS: 83.50.Jf, 83.50.Uv, 83.80.Tc, 83.80.Sg, 83.85.Rx
Zdenek Stary | FAU Erlangen-Nuremberg | Germany
11:00 – 11:30
Development of Novel Orifice Die Design for Precise Entrance Pressure Drop Measurements
Autors:
Martin Zatloukal and Jan Musil
Affiliation:
Polymer Centre, Faculty of Technology, Tomas Bata University in Zlín, TGM 275, Zlín 76272, Czech Republic.
Abstract:
In this work, novel patent pending orifice die design for precise extensional viscosity data determination from entrance pressure drop measurements has been developed and tested both, theoretically (through Finite Element Analysis) and experimentally. It has been demonstrated that the proposed novel orifice die allows much more precise extensional viscosity measurements for polymer melts in comparison with conventionally used orifice dies.
Keywords: Orifice die, Entrance pressure drop, Extensional viscosity, Polymer melts.
PACS: 47.11.Fg, 47.50.Cd, 47.50.Ef, 83.10.Ff, 83.50.Ha, 83.50.Uv, 83.80.Sg, 83.85.Cg, 83.85.Rx
Martin Zatloukal | Tomas Bata University in Zlin | Czech Republic
11:30- 13:00
Lunch & Exhibition
NOVEL RHEOLOGICAL TECHNIQUES II
(Chairman: Mike Martyn)
13:00- 13:30
Non-Linear Rheology of Polymer Melts
Autor:
Susana Filipe
Affiliation:
Borealis Polyolefine GmbH, InnoTech Operational Support, Advanced Polymer Structure Characterisation, Sankt Peter Strasse 25, 4021 Linz, Austria.
Abstract:
The continuous demand for high performance products is the driving force for the development of state-of-the-art materials with outstanding processability and mechanical strength. In order to fulfill these properties, an appropriate tailoring of the molecular structure is a requirement. Such tailoring can only be achieved provided that suitable and sensitive characterization techniques are available. The dominance of complex flows in most of the industrial processes requires the understanding of the rheological properties under the non-linear viscoelastic regime. Within the present work Large Amplitude Oscillatory Shear (LAOS) will be applied to a series of industrial polypropylene and polyethylene based materials. This work will provide additional insights on the relationship between given rheological parameters from LAOS flow (|G’1/G’3|) and molecular topology. The use of the third order Chebyshev elastic and viscous coefficients, e3 and ν3, provided an understanding of the physical nature of the non-linear viscoelastic response.
Keywords: Non-linear rheology, Large amplitude oscillatory shear, Uniaxial extensional flow,
Polyethylenes, Polypropylenes, Long-chain branching.
PACS: 61.25.hk
Susana Filipe | Borealis Polyolefine | Austria
13:30 – 14:00
Recent Developments on On-line Rheometry to Monitor the Extrusion Process
Autors:
Sacha Trevelyan Mould, Joana Margarida Barbas, João Miguel Nóbrega, Ana Vera Machado and José António Covas
Affiliation:
IPC –Institute for Polymers and Composites, Department of Polymer Engineering, University of Minho, 4800-058 Guimarães, Portugal.
Abstract:
On-line rheometers are generally inserted between extruder and die and generate data that is typically utilized for quality control purposes. However, on-line rheometers have also the potential to detect changes in structure, morphology, or composition of a given material system, thus assisting materials research and processing optimization, if they can be used along the axis of the extruder or compounder. The authors have previously developed on-line capillary and rotational/oscillatory rheometers that can be inserted and used at specific locations along the extruder. Since these devices are operated manually, their manipulation may be cumbersome and data may lack reliability. This work presents new versions of these rheometers, with improved functionalities and motorized operation. Details on the validation of one of them is also given.
Keywords: Rheometry, On-line, Capillary, Oscillatory, Extrusion.
PACS: 83.50.Uv, 83.85.Cg, 83.85.Jn, 83.85.Vb
Miguel Nobrega | University of Minho | Portugal
14:00 – 14:30
Fourier Transformation Analysis in Capillary Flow – A New Option to Detect Flow Instabilities (Shark Skin)
Autor:
Joachim Sunder
Affiliation:
Goettfert GmbH, Siemensstr. 2, 74722 Buchen, Germany.
Abstract:
Flow instabilities cause various problems in extrusion blow- or flat film processes. Especially shark skin is affected by molecular structure. This phenomenon is analyzed in variou scientific works using apparatus that are complex or difficult in operation. A new set-up, now available is being presented as an option for new and existing capillary rheometers or lab extruders, consisting of a special designed die, a fast responsive transducers system and evaluation software. The software allows the evaluation of diverse pressure frequency regimes causing flow instabilities and generate statistics. Measurement examples are given for different shear rates and polymers. The shark skin effect can be detected even before it is visible on the extrudate. The measured frequency regimes are related to molecular parameters
Keywords: Capillary rheometer, Flow instabilities, Fast response pressure transducer, Fourier
analysis, Shark skin effect.
PACS: 47.20.-k
Joachim Sunder | GÖTTFERT Werkstoff-Prüfmaschinen | Germany
14:30 – 15:00
Cofee break & Exhibition
NOVEL RHEOLOGICAL TECHNIQUES III
(Chairman: Petr Filip)
15:00 – 15:30
Diagnostics of Apparent Wall Slip in Aqueous Polymer Solutions
Autors:
Ondřej Wein 1), Valentin V. Tovčigrečko 1), Václav Sobolík 2) and Marek Večeř 3)
Affiliations:
1) Institute of Chemical Process Fundamentals of ASCR, v.v.i., 16502 Prague 6, Rozvojova 135, Czech Republic.
2) LMTAI, University of La Rochelle, 17042 La Rochelle, Av. Michel Crepeau, France.
3) VŠB – Technical University of Ostrava, 708 33 Ostrava, 17. listopadu 15, Czech Republic.
Abstract:
Two experimental methods, apparent-wall-slip (AWS) rotational viscometry with “Morse-taper” sensors and electrodiffusion (ED) flow diagnostics with auto-calibrated friction probes, are used to study velocity profiles in aqueous solutions of high-molecular polysaccharides. By comparing the velocity data from the both methods, estimates are obtained of depleted layer thickness in dependence on wall shear stress.
Keywords: Apparent wall slip (AWS), Electrodiffusion diagnostics (ED) of flow, Depleted
layer thickness.
PACS: 83.50.Rp
Ondrej Wein | ICPF ASCR | Czech Republic
15:30 – 16:00
Characterization of Microstructure and Molecular Dynamics with High Frequency Oscillatory Techniques
Autors:
Torsten Remmler 1), Samiul Amin 2), Andrea Ferrante 3) and Wolfgang Pechhold 4)
Affiliations:
1) Malvern Instruments GmbH, Rigipsstraße 19, D-71083 Herrenberg, Germany.
2) Malvern Instruments Ltd, Enigma Business Park, Grovewood Road, Worcestershire WR14 1XZ, UK.
3) Unilever R&D, Port Sunlight, Wirral, Merseyside, CH62 4ZD, UK.
4) Institute for Dynamic Material Testing, Helmholtzstraße 20, D-89081 Ulm, Germany.
Abstract:
To characterize the rheological behaviour of complex viscoelastic fluids, polymer melts and other soft materials, motor-drive controlled rheometers are mainly used, either at constant stress or strain rate, or in the oscillatory mode. The latter has proved advantageous to discover the viscoelastic functions G*, η*, J* as fingerprints of the material under investigation, it`s composition, molecular modelling and applicability. A conclusive analysis of such a viscoelastic spectrum can only be achieved if the amplitudes chosen guarantee linearity and if the frequency range covers more than 6 decades to reach the low kHz-domain. Investigations of many materials with motor-drive controlled rheometers are limited at higher frequencies and reach the above mentioned goal by applying the time-temperature superposition principle, i.e. the mastercurve technique. Since this method is restricted to rheologically simple materials (e.g. some polymer melts), but exclude those of small activation energies and others with temperature-sensitive chemical/physical structures including phase transitions, oscillating rheometry should be extended into higher real-frequency ranges, to establish useful linear viscoelastic spectroscopy. Since complex fluids can have structural arrangement over a wide range of lengthscales and their relaxation mechanisms can impact the dynamics over a wide range of timescales, multiple techniques need to be employed in order to accurately and fully establish the links between rheology, microstructure & dynamics. This is also critical information, required for fully validating developed theory and models. In this talk, advantages and limits of classical oscillatory rheometry will be covered, handling and principle of operation of two high frequency options are introduced and typical examples for real frequency spectra on soft matter, such as polymer melts, polymer solutions and weak gels will be shown. A xanthum gum based system has been investigated not only by traditional rheology and high frequency mechanical rheology but also through DWS based optical microrheology. The talk will focus on how unique insights from each of these techniques leads to a better understanding of the overall microstructure-rheology linkages in this system.
Keywords: Mechanical spectroscopy, High frequency, Linear viscoelasticity, DWS.
PACS: 83.85.Cg, 83.85.Vb
Torsten Remmler | Malvern | Germany
18:30
Conference dinner
July 29, 2009
NON-NEWTONIAN FLUID MECHANICS
(Chairman: Ondrej Wein)
8:00 – 8:30
Visualisation and Analysis of Polyethylene Coextrusion Melt Flow
Autors:
Mike T. Martyn 1), Phil D. Coates 1) and Martin Zatloukal 2)
Affiliations:
1) IRC in Polymer Science & Technology, School of Engineering, Design & Technology University of Bradford, Bradford BD7 1DP, UK.
2) Polymer Centre, Faculty of Technology, Tomas Bata University in Zlín, TGM 275, Zlín, Czech Republic.
Abstract:
Polymer melts experience complex, time variant, stress and deformation fields on their passage through fixed geometries in many conversion operations. Flow complexity is further increased in operations involving the co-joining of two or more melt streams where one confining boundary is moving and viscoelastic. Such a complex situation arises in coextrusion processes. This work covers experimental studies on polyethylene melt flows in complex coextrusion geometries with a view to understanding the stress fields involved and their effects on flow stability. A 30° coextrusion geometry is studied using two extrusion arrangements. In one arrangement a single extruder is used to feed a ‘bifurcated’ die design wherein the melt stream is split prior to, and rejoined after, a divider plate in the die. In the other design melt streams are delivered to, and converged at 30°, using two independent extruders. In a second die melt streams are brought together at 90°. In each die arrangement melt flow in the confluent region and die land to the die exit was observed through side windows of a visualisation cell. Velocity ratios of the two melt streams were varied and layer thickness ratios producing instability are determined for each melt for a variety of flow conditions. Stress and velocity fields in the coextrusion arrangements were quantified using stress birefringence and particle image velocimetry techniques. The study demonstrates conclusively that wave type interfacial instability occurred in the coextrusion geometries when the same low density polyethylene melt is used in each stream. This observation occurred at specific, repeatable, stream layer ratios in each die arrangement. The complex flows were numerical modelled using a modified Leonov model and Flow 2000™ software. There was reasonable agreement between modelled at experimentally determined stress fields. Modelling however provided far more detailed stress gradient information than could be resolved from the optical techniques. A total normal stress difference (TNSD) sign criterion was used to predict the critical layer ratio for the onset of the interfacial instability in one die arrangement and good agreement between theory and experiment has been obtained. The study conclusively demonstrates wave type interfacial instability in the coextrusion process is not caused by process perturbations potentially introduced by extruder screw rotation but is associated with process-history dependant differences in melt elasticity.
Keywords: Coextrusion, Instability, Imaging, Modeling.
PACS: 47.11.Fg, 47.20.Gv, 47.20.Ma, 47.50.Gj, 83.50.Ha, 83.50.Uv, 83.60.Wc, 83.80.Sg,
83.85.Ei
Mike Martyn | University of Bradford | United Kingdom
8:30 – 9:00
Wall Effects on a Single Spherical Particle Moving Through a Carreau Model Fluid
Autors:
Ivan Machač, Jaroslav Strnadel and Alexander Surý
Affiliation:
University of Pardubice, Institute of Environmental and Chemical Engineering, Faculty of Chemical Technology, Studentská 573, 532 10 Pardubice, Czech Republic
Abstract:
The steady slow motion of solid spheres through a Carreau model fluid contained in a cylindrical tube has been solved numerically using a finite element method by means of the COMSOL software package for steady non-Newtonian flows. From the resulting stress fields, the drag force on the sphere, drag coefficient, drag coefficient corrective factor, and wall correction factor have been evaluated in dependence on the Carreau model parameters and the sphere-to-tube diameter ratio. The results of the wall correction factor calculations are presented herein and compared with some experimental data.
Keywords: Solid spheres, Non-Newtonian fluid.
PACS: 47.50.-d, 47.50.Ef, 47.50.Cd
Ivan Machac | University of Pardubice | Czech Republic
9:00 – 9:30
Quasisimilarity of Helical Power-Law Fluid Flow in Concentric Annuli
Autors:
Petr Filip and Jiří David
Affiliation:
Institute of Hydrodynamics, Acad. Sci. Czech Rep., Pod Patankou 5, 166 12 Prague 6, Czech Republic.
Abstract:
The aim of this contribution is to present a quasisimilarity solution of helical power-law fluid flow in concentric annuli with a rotating inner cylinder. Emphasis is paid to the relation axial volumetric flow rate vs. axial pressure gradient. It is shown that for sufficiently broad region of entry parameters (rheological, geometrical, and kinematical) there is a possibility to derive quasisimilarity transformations enabling relatively easy determination of the above relation.
Keywords: Quasisimilarity, Power-law fluids, Helical flow, Concentric annuli.
PACS: 83.10.Bb, 83.50.Ha
Petr Filip | Institute of Hydrodynamics ASCR | Czech Republic
9:30 – 10:30
Cofee break & Poster section & Exhibition
A Remark to the Tube Theory
Autors:
Alexander A. Kharlamov, Petr Filip and Petra Svrcinova
Affiliation:
Institute of Hydrodynamics, Acad. Sci. Czech Rep., Pod Patankou 5, 166 12 Prague 6, Czech Republic.
Abstract:
The classical Doi-Edwards (DE) model with Independent Alignment (IA) approximation represents a basic issue for tube theories. In this contribution there is presented alternative approach not taking into account the IA approximation. Under external deformation the polymer sample molecules are deformed affinely, consequently they retract but do not preserve their direction. The end-to-end vector of a molecule after retraction becomes distributed with a certain probability. This probability is calculated using geometrical considerations of retracting motion.
Keywords: DE model, Independent alignment, Retraction, Damping function.
PACS: 66.20.Cy; 83.10.Gr; 83.10.Kn
Alexander Kharlamov | Institute of Hydrodynamics ASCR | Czech Republic
Cake Filtration in Viscoelastic Polymer Solutions
Autors:
Alexander Surý and Ivan Machač
Affiliation:
University of Pardubice, Institute of Environmental and Chemical Engineering, Studentská 95, 532 10 Pardubice, Czech Republic.
Abstract:
In this contribution, the filtration equations for a cake filtration in viscoelastic fluids are presented. They are based on a capillary hybrid model for the flow of a power law fluid. In order to express the elastic pressure drop excess in the flow of viscoelastic filtrate through the filter cake and filter screen, modified Deborah number correction functions are included into these equations. Their validity was examined experimentally. Filtration experiments with suspensions of hardened polystyrene particles (Krasten) in viscoelastic aqueous solutions of polyacryl amides (0.4 % and 0.6 %wt. Kerafloc) were carried out at a constant pressure on a cylindrical filtration unit using filter screens of different resistance.
Keywords: Viscoelastic filtration, Filter screen resistance, Filtration equation, Elastic effects.
PACS: 47.50.-d, 47.50.Ef
Alexander Sury | University of Pardubice | Czech Republic
Fall of Spherical Particles in Viscoelastic Fluids
Autors:
Jaroslav Strnadel and Ivan Machač
Affiliation:
University of Pardubice, Institute of Environmental and Chemical Engineering, Faculty of Chemical, Technology, Studentská 573, 532 10 Pardubice, Czech Republic.
Abstract:
In this contribution, the results of experimental determination of the drag coefficient correction factor for spherical particles moving slowly through a Carreau viscosity model fluid are presented. The experimental values of the correction factor, which were evaluated from measurements of terminal falling velocity of seventeen types of spherical particles in viscoelastic polymer solutions, are compared with those calculated numerically using a finite elements method. The results obtained confirm that in the case of shear thinning concentrated polymer solutions the viscoelastic effects are only of minor significance. However, in the case of less concentrated high-molecular polymer solutions in polyalkylene glycol Emkarox an evident drag enhancement has been observed.
Keywords: Shear-thinning fluids, Viscoelastic fluids, Drag coefficient, Carreau viscosity model,
Deborah number.
PACS: 47, 83.80.Rs, 83.85.Cg
Jaroslav Strnadel | University of Pardubice | Czech Republic
Investigation of Internal Die Drool Phenomenon for Different HDPEs
Autors:
Jan Musil and Martin Zatloukal
Affiliation:
Polymer Centre, Faculty of Technology, Tomas Bata University in Zlín, TGM 275, 762 72 Zlín, Czech Republic.
Abstract:
In this work, two different HDPEs were investigated from rheological as well as die drool phenomenon point of view. It has been revealed that long-chain branching and low polymer melt elasticity significantly reduce die drool phenomena at the die exit region.
Keywords: Die drool, Extrusion, Shear viscosity, Extensional viscosity.
PACS: 47.50.Ef, 47.50.Gj, 83.50.Jf, 83.50.Uv, 83.60.Wc, 83.80.Sg, 83.85.Cg, 83.85.Rx
Jan Musil | Tomas Bata University in Zlin | Czech Republic
Mold Cavity Roughness vs. Flow of Polymer
Autors:
Michal Stanek, Miroslav Manas and David Manas
Affiliation:
Tomas Bata University in Zlín, Faculty of Technology, Department of Production Engineering, TGM 275, 76272 Zlín, Czech Republic.
Abstract:
Injection molding represents such a way of polymer processing that requires injection of polymer melt into the mold cavity with very high injection rate. The fluidity of polymers is affected by many parameters (mold design, melt temperature, injection rate and pressure). The main objective of this paper is the study of influence of surface roughness of mold cavity of the polymer melts flow. Evaluation of set of data obtained by experiments where the testing conditions were widely changed shows that quality of cavity surface affects on the length of flow.
Keywords: Injection molding, Surface roughness, Fluidity, Polymer, Cavity.
PACS: 83.50.Uv, 83.80.Sg
Michal Stanek | Tomas Bata University in Zlin | Czech Republic
Characterization of Carbon Nanotube Based Polymer Composites Through Rheology
Autors:
Robert Olejnik 1), Pengbo Liu 1, 2), Petr Slobodian 1), Martin Zatloukal 1) and Petr Saha 1)
Affiliations:
1) Tomas Bata University in Zlín, Faculty of Technology, T.G.M. 275, 762 72 Zlín, Czech Republic.
2) Sichuan University, State Key Laboratory of Polymer Materials Engineering of China.
Abstract:
Poly(methyl methacrylate)/Multi-wall carbon nanotubes (MWCNT) nanocomposites were prepared by solution method. Here the dispersions of MWCNT in PMMA solutions were sonicated for appropriate time followed by dispersions coagulation. Both types of CNT materials were used such as pure MWCNT and the same MWCNT after their adequate surface treatment. The aim of treatment was to covalently attach organic material onto surface of CNT to process their better dispersion in polymeric matrix leading to more effective CNT reinforcement effect. The state of CNT dispersion was characterized thought rheology measurements with help of parameters like elasticity and viscosity of the melt. Also the effect of sonication onto pure PMMA matrix was determined.
Keywords: Carbon nanotubes, Polymer composites, Rheology.
PACS: 81.05.Qk, 81.05.Tp
Robert Olejnik | Tomas Bata University in Zlin | Czech Republic
Importance of Viscoelastic Property Measurement of a New Hydrogel for Health Care
Autors:
Niladri Roy, Nabanita Saha, Takeshi Kitano and Petr Saha
Affiliation:
Polymer Centre, Faculty of Technology, Tomas Bata University in Zlin, TGM 275, 762 72 Zlin, Czech Republic.
Abstract:
A simple technology based new hydrogel “PVP-CMC-BA” has been prepared by the scientists of Tomas Bata University in Zlin, Czech Republic. Its swelling property (in presence of water, human blood and different pH), antimicrobial property (in presence of skin infection causing agents like: Staphylococcus aureus; bacteria and Candida albicans; fungi) and viscoelastic properties such as storage modulus (G’), loss modulus (G”) and complex viscosity (η*) were investigated at room temperature (25-28oC) which demonstrate that PVP-CMC-BA hydrogel is maintaining requisite properties for health care application, specially as a wound dressing material. The elasticity and antimicrobial property of PVP-CMC-BA is directly correlated with percentage of boric acid, an antiseptic agent. The consequential values of viscoelastic properties of the hydrogel (before drying) enable us to understand its specific flexible condition to apply on the surface of human body.
Keywords: Hydrogels, Boric acid, Swelling, Viscoelastic properties, Wound dressing.
PACS: 87, 83.85.Cg, 83.85.Vb
Niladri Roy | Tomas Bata University in Zlin | Czech Republic
Rheological Behavior of Composites Based on Carbon Fibers Recycled from Aircraft Waste
Autors:
Lucie Marcaníková, Berenika Hausnerová and Takeshi Kitano
Affiliation:
Polymer Centre, Faculty of Technology, Tomas Bata University in Zlín TGM 275, 762 72 Zlín, Czech Republic.
Abstract:
Rheological investigation of composite materials prepared from the recycled aircraft waste materials based on thermoset (epoxy/resin) matrix and long carbon fibers (CF) is presented with the aim of their utilization in consumer industry applications. The carbon fibers recovered via thermal process of pyrolysis were cut into about 150 μm length and melt mixed with thermoplastic matrices based on polypropylene (PP) and polyamide 6 (PA) and various modifiers – ethylene-ethyl acrylate-maleic anhydride (E-EA-MAH), polypropylene grafted maleic anhydride (PP-g-MA) and poly(styrene)-block-poly(ethylene-co-but-1-ene)-blockpoly( styrene) (SEBS). Rheological, electrical, mechanical, thermal and morphological results revealed the composites of recycled CF and PP/PP-g-MA as well as PA/E-EA-MAH to be the most promising candidates for new applications.
Keywords: Carbon fiber, Recycling, Rheological properties, Mechanical properties.
PACS: 81.05.Qk, 81.70.Bt, 83.85.Cg
Lucie Marcanikova | Tomas Bata University in Zlin | Czech Republic
Modeling of Non-Isothermal Film Blowing Process for Polyolefines by Using Variational Principles
Autors:
Roman Kolarik and Martin Zatloukal
Affiliation:
Polymer Centre, Faculty of Technology, Tomas Bata University in Zlín, TGM 275, 762 72 Zlín, Czech Republic.
Abstract:
In this work, film blowing process analysis has been performed theoretically by using minimum energy approach for non-Newtonian polymer melts considering non-isothermal processing conditions and the obtained predictions were compared with both, theoretical and experimental data (bubble shape, velocity and temperature profiles) taken from the open literature. It has been found that model predictions are in very good agreement with the corresponding experimental data.
Keywords: Non-isothermal film blowing, Polymer processing modeling, Variational principles.
PACS: 47.50.-d, 83.10.Gr, 83.50.Uv, 83.60.St, 83.80.Sg
Roman Kolarik | Tomas Bata University in Zlin | Czech Republic
3D Simulation of the Fluted Mixer Element Behavior
Autors:
Pavel Kubik 1), Jiri Vlcek 2), Jiri Svabik 2), Ilja Paseka 2) and Martin Zatloukal 3)
Affiliations:
1) Department of Polymer Engineering, Faculty of Technology, Tomas Bata University in Zlín, TGM 275, Zlín 76272, Czech Republic.
2) Compuplast International, Inc., P.O. Box 24, Nerudova 158, Zlín 76001, Czech Republic.
3) Polymer Centre, Faculty of Technology, Tomas Bata University in Zlín, TGM 275, Zlín 76272, Czech Republic.
Abstract:
In this work, two different fluted mixing elements have been investigated by 3D FEM analysis. It has been found that open fluted mixing element has lower temperature losses than closed fluted mixer which can be explained by the presence of the layer, which is slowly rotating very close to the barrel in the case of the open fluted mixing element. It also has been found that the shear stress in this isolation polymer melt layer is lower than 20 kPa, which may leads to polymer melt degradation. From the obtained theoretical data, it can be concluded that open fluted mixing element may behave much more differently than the closed fluted mixing element.
Keywords: Fluted mixer, 3D simulation, Isolation layer.
PACS: 83.50.Ha
Pavel Kubik | Tomas Bata University in Zlin | Czech Republic
Coextrusion Flow Analysis for a Multilayer Plastic Fuel Line Die
Dietmar Böttner | TI Automotive (Fuldabrück) GmbH | Germany
Investigation of Polyurethane Electrospinning Process Efficiency
Autors:
Dusan Kimmer 1), Martin Zatloukal 2), David Petras 1), Ivo Vincent 1) and Petr Slobodian 2)
Affiliations:
1) SPUR a.s., T. Bati 299, 764 22 Zlín, Czech Republic.
2) Polymer centre, Faculty of Technology,Tomas Bata University in Zlín, TGM 275, 762 72 Zlín, Czech Republic.
Abstract:
The electrospinning process efficiency of different PUs has been investigated. Specific attention has been paid to understand the role of PU soft segments and synthesis type on the stability of the PU solution and electrospinning process as well as on the quality/property changes of the produced nanofibres. PU samples before and after the process were analyzed rheologicaly and relaxation spectra were determined for all of them from frequency dependent loss and storage moduli measurements. It has been found that rheological analysis of PU, which is used for electrospinning process, can be useful tool from electrospinning process efficiency and optimization point of view. Nanolayers homogeneity during several hours of manufacture in optimized electrospinning process is proved by selected properties from aerosol filtration.
Keywords: Nanofiber, Electrospinning, Polyurethanes, Rheological analysis, Relaxation
spectra, Nanolayers homogeneity, Process stability, Continues manufacture.
PACS: 62.23.St, 68.37.Hk, 81.16.Be, 81.16.Rf, 82.35.Lr, 82.45.Yz, 87.85.Uv
Dusan Kimmer | SPUR a.s. | Czech Republic
The Use of Digital Image Analysis and Rheological Tools to Characterize Nanofiber Based Textiles
Autors:
Wannes Sambaer 1), Martin Zatloukal 1) and Dusan Kimmer 2)
Affiliations:
1) Polymer Centre, Faculty of Technology, Tomas Bata University in Zlin, TGM 275, 762 72 Zlin, Czech Republic.
2) SPUR a.s., T. Bati 299, 764 22 Zlin, Czech Republic.
Abstract:
Polyurethane (PU) solved in dimethylformamide (DMF) was electrospun under one set of conditions on two different support textiles. The mechanical properties were measured and aerosol filtration tests were done. The hole size distribution was calculated with a new digital image analysis methodology on SEM images. It has been found that supporting textiles have very high effect on mechanical properties and filtration efficiency of nanofiber mats (even if their fiber diameter distributions were practically identical), which can be explained by different porosity of the prepared samples.
Keywords: Nanofiber, Electrospinning, Mechanical properties, Filtration, Digital image analysis.
PACS: 81.07.-b, 61.46.Km, 62.23.Hj, 62.25.Mn, 95.75.Mn
Wannes Sambaer | Tomas Bata University in Zlin | Czech Republic
INTRODUCTION OF NOVEL RHEOLOGICAL TOOLS
(Chairman: Miguel Nobrega)
10:30 – 10:50
Additional modules and combined measuring methods for the rheological characterization of polymers
Michael Ringhofer | Anton Paar, GmbH | Austria
10:50 – 11:10
Advantages and applications for separated motor and transducer rheometers
Massimo Baiardo | TA Instruments | USA
11:10 – 11:30
More rheology, less effort. The concept of the new malvern kinexus rheometer
Torsten Remmler | Malvern | Germany
11:30 – 11:50
The MARS Factor in Rheology – New Nano-Torque Capabilities
Ansgar Frendel | Thermo Fisher Scientific | Germany
11:50 – 13:30
Lunch & Exhibition
MODELING OF POLYMER PROCESSING
(Chairman: Jiri Vlcek)
13:30 – 14:00
Profile Extrusion Dies: The Effect of Machining Inaccuracies on Flow Balance and Its Dependence on the Design Strategy Used
Autors:
João Miguel Nóbrega, Simão Pedro Pereira and Olga Sousa Carneiro
Affiliation:
IPC/I3N-Institute for Polymers and Composites, Department of Polymer Engineering, University of Minho, Campus de Azurém, 4800-058 Guimarães, Portugal.
Abstract:
The achievement of an even flow distribution is one of the main tasks of the profile die design procedure. For this purpose there are two different alternative strategies, namely those that involve or not modifications of the die land cross section. As shown in previous works [1], those alternative strategies show different sensitivities to variations of the process parameters and material rheology, leading to the production of profiles with different tendency to distort in use. Additionally, it is well-known that some of the problems faced during the production of a new profile arise in the manufacturing stage of the die flow channel and are related with inaccuracies associated to the machining equipment used. These inaccuracies affect the final flow channel geometry and are unavoidable, but are not taken into account during the design stage. In this work an in-house 3D numerical modeling code based on the finite volume method is used to study the effect of slight dimensional variations (similar to those arising in the machining stage) on the performance of extrusion dies designed with the above referred strategies.
Keywords: Profile extrusion dies, Flow balance, Machining inaccuracies.
PACS: 47.85.md, 47.85.MINTRODUCTION
Miguel Nobrega | University of Minho | Portugal
14:00 – 14:30
Simulation of Screws for Injection Molding
Autors:
Jiri Vlcek 1), Luke Miller 2) and C. T. Huang 3)
Affiliations:
1) Compuplast International, Inc., Zlin, Czech Republic.
2) XALOY, New Castle, Pennsylvania, USA.
3) Coretech, Hsin-chu, Taiwan.
Abstract:
The presentation will deal with simulation of extruder for the injection molding process. It shows the theory and how the method of simulation of an extruder for the extrusion process is modified to cover the effects in injection molding, mainly the facts that the screw does not rotate for a certain time and it moves backward during turning and melting. To see the quality of the prediction of such a modified program a set of experiments was performed. A comparison of the results of these experiments with the program prediction will be shown. The presentation will also cover the most important variables to be checked for a good extruder performance in the injection molding process.
Keywords: Plastification screws simulation, Injection molding simulation, Plastification screws
performance.
PACS: 46.15.-x, 47.11.Bc, 47.51.+a
Jiri Vlcek | Compuplast International | Czech Republic
14:30 – 15:00
Stochastic Flow Modeling for Resin Transfer Moulding
Autors:
Frederik Desplentere 1), Ignaas Verpoest 2) and Stepan Lomov 2)
Affiliations:
1) Department of Mechanical Engineering, Katholieke Hogeschool Brugge Oostende, Zeedijk 101, 8400 Ostend, Belgium.
2) Metallurgy & Materials Engineering Department, Katholieke Universiteit Leuven, Kasteelpark Arenberg 44, 3001 Leuven, Belgium.
Abstract:
Liquid moulding processes suffer from inherently present scatter in the textile reinforcement properties. This variability can lead to unwanted filling patterns within the mould resulting in bad parts. If thermoplastic resins are used with the in-situ polymerisation technique, an additional difficulty appears. The time window to inject the material is small if industrial processing parameters are used (< 5 minutes). To model the stochastic nature of RTM, Darcy’s description of the mould filling process has been used with the permeability distribution of the preform given as a random field. The random field of the permeability is constructed as a correlated field with an exponential correlation function. Optical microscopy and X-ray micro-CT have been used to study the stochastic parameters of the geometry for 2D and 3D woven textile preforms. The parameters describing the random permeability field (average, standard deviation and correlation length) are identified based on the stochastic parameters of the geometry for the preforms, analytical estimations and CFD modelling of the permeability. In order to implement the random field for the permeability and the variability for the resin viscosity, an add-on to the mould filling simulation software PAM-RTMTM has been developed. This analysis has been validated on case studies.
Keywords: Stochastic simulation, Correlated distribution, Resin Transfer Moulding, X-ray
micro CT.
PACS: 02.70.Uu, 81.20.Hy, 81.05.Qk
Frederik Desplentere | Katholieke Hogeschool Brugge – Oostende | Belgium
15:00 – 15:30
Refreshment & Exhibition
RHEOLOGY OF BLENDS AND RUBBERS
(Chairman: Ivan Machac)
15:30 – 16:00
Microrheological Description of the Phase Structure Evolution in Polymer Blends. State of Art and Open Problems
Autor:
Ivan Fortelný
Affiliation:
Institute of Macromolecular Chemistry AS CR, v.v.i., Heyrovsky Sq. 2, 162 06 Prague 6, Czech Republic.
Abstract:
The contribution discuses present state of art at description of the phase structure evolution in molten immiscible binary polymer blends in flow and in quiescent state on microrheological level. Discussion is focused on quality of predictions of the phase structure of immiscible polymer blends after mixing and processing. Main results of the theory and open problems, which solution is important for control of the blend structure and properties, are stressed.
Keywords: Polymer blends, Microrheology, Phase structure evolution, Droplet breakup,
Coalescence.
PACS: 83.50.Xa
Ivan Fortelny | Institute of Macromolecular Chemistry ASCR | Czech Republic
16:00 – 16:30
Morphology Development in Polymer Blends under Uniaxial Elongation
Autor:
Zdeněk Starý
Affiliation:
Institute of Polymer Materials, Friedrich-Alexander University Erlangen-Nuremberg, Martensstr. 7, 910 58 Erlangen, Germany.
Abstract:
The properties of immiscible polymer blend are distinctively influenced not only by the properties of blends components but also by its phase structure. Therefore, investigation of relationships between deformation and morphology development in polymer blends under elongational deformation is of great interest. In this work the features of the creep elongational experiments and their benefits regarding the morphology development are discussed. Furthermore, the study of deformation of the dispersed droplets during the creep experiments in uncompatibilized and compatibilized polystyrene/linear low-density polyethylene blends is presented.
Keywords: Blends, Morphology, Uniaxial elongation, Rheology, Compatibilization.
PACS: 83.50.Jf, 83.50.Uv, 83.80.Tc, 83.80.Sg, 83.85.Rx
Zdenek Stary | FAU Erlangen-Nuremberg | Germany
16:30 – 17:30
Refreshment & Exhibition
17:30
End of the conference