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Mechanikai feszltsgek relaxcija a hetero-modulus s hetero-viszkzus komplex kermikban

Nanorszecske-polimer klcsnhatsok j molekulris megkzeltse: alkalmazsi plda lizofoszfolipid micellapoliakrilsav rendszerre

Az vegszlgyrts optimalizlsnak lehetsges mdszerei

Az Al2O

3-Al porelegy keversi

idejnek hatsa az alumnium-oxid kermik minsgre

Szalmabla anyag falak tzvdelmi krdsei

2010/4

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TARTALOM

98 Mechanikai feszltsgek relaxcija a hetero-modulus

s hetero-viszkzus komplex kermikban GMZE A. Lszl Ludmila N. GMZE

102 Nanorszecske-polimer klcsnhatsok j molekulris

megkzeltse: alkalmazsi plda lizofoszfolipid micella-

poliakrilsav rendszerre Yves CHAPRON Alain PORQUET Montserrat FILELLA

108 XXV. Tgls Napok TTH-ASZTALOS Rka

110 Az vegszlgyrts optimalizlsnak lehetsges mdszerei SZEMN Jzsef

114 Beszmol vegipari szakmai konferencirl LIPTK Gyrgy

116 Az Al2O3-Al porelegy keversi idejnek hatsa az

alumnium-oxid kermik minsgre Anton KAYGORODOV Vladimir KHRUSTOV

119 ICC3 Beszmol a 3. Nemzetkzi Kermia Kongresszusrl EGSZ dm MAGYAR dm

120 Szalmabla anyag falak tzvdelmi krdsei MDER Istvn Ferenc LUBLY va TAKCS Lajos Gbor

124 Egyesleti s szakhrek

CONTENT

98 Mechanical stress relaxation in hetero-modulus,

hetero-viscous complex ceramic materials Lszl A. GMZE Ludmila N. GMZE

102 New molecular approach for the simulation of nanoparticle

polymer interactions: application to the system formed

by a lysophospholipidic micelle and polyacrylic acid Yves CHAPRON Alain PORQUET Montserrat FILELLA

108 25th Days of Brick Rka TTH-ASZTALOS

110 Possible methods of optimising glass fibre production Jzsef SZEMN

114 Report of glass conference in Hungary Gyrgy LIPTK

116 The influence of Al2O3+Al powders stirring time on the

quality of alumina based ceramics Anton KAYGORODOV Vladimir KHRUSTOV

119 3rd International Congress on Ceramics dm EGSZ dm MAGYAR

120 Fire safety questions of straw bale walls MDER Istvn Ferenc LUBLY va TAKCS Lajos Gbor

124 Society and professional news

ptanyagptanyag 2010/4ptanyagptanyag 2010/4

ANYAGTUDOMNY MATERIALS SCIENCE

Mechanical stress relaxation in hetero-modulus, hetero-viscous complex ceramic materials

LSZL A. GMZE Department of Ceramics and Silicate Engineering, University of Miskolc [email protected] N. GMZE IGREX Engineering Service Ltd. [email protected] Received: 22.11.2010. rkezett: 2010.11.22.

Hetero-modulus, hetero-viscous complex materials have several advantages in accordance to mechanical and thermal properties comparing with the traditional ceramics and ceramic matrix composites. In this paper the authors examined in details the high speed collision processes between flying metallic objects and ceramics, such as -Si3N4, -Si3N4, Si2ON2, SiAlON, AlN and 3Al2O32SiO2 reinforced alumina matrix hybrid materials, as well as their rheo-mechanical structures and properties. Understanding the high speed collision process, material structures, rheological properties of such a complex hybrid material, the authors in this paper mathematically describe the mechanical shear stress and its relaxation during and after high speed collisions in -Si3N4, -Si3N4, Si2ON2, SiAlON, AlN and 3Al2O32SiO2 reinforced alumina matrix composites. The dynamic strength of the developed and examined corundum matrix complex materials was tested through collision with high density metallic flying bodies, with speed higher than 900 m/sec and described in works [27, 29, 42]. Analytical methods applied in this research were scanning electron microscopy, X-ray diffraction and energy dispersive spectrometry. Digital image analysis was applied to microscopy results, to enhance the results of transformation. Keywords: ceramics, CMC, elasticity, hybrid materials, plasticity, stress relaxation, viscosity

Lszl A. GMZEis head of Department of Ceramics and Silicate

Engineering in the University of Miskolc since 1999. He has got scientific degree Candidate of Technical and Engineering Sciences at Moscow

University M. I. S. I. in 1985, and has a wide range of experiments both in engineering and research works at different companies and in teaching of students at universities. Finishing

the Civil Engineering University of Moscow (Russia) in 1973, L. A. Gmze started his working

activity as structural engineering at the design department in Hungarian firm Building Ceramics

(pletkermia) in Budapest. In 1986 he was already the managing director of the famous

Hungarian porcelain manufactory HOLLHZA. Leaving Hollhza in 1990 he used to work as associated professor at University of Miskolc.

Laszlo A. Gmze is member of several Hungarian and international organization in fields of

ceramics, material sciences and chemistry. He is member of Kerpely Antal Doctoral School of material sciences and technologies. Since 1996

he has successfully supervised several PhD students in fields of ceramics and ceramic matrix

composites.

Ludmila N. GMZEis the managing director of engineering service

firm IGREX Ltd. Finishing the Civil Engineering University of Moscow (Russia) in 1974 she

started her working activity as structural engineer at Hungarian design institution

VIZITERV in Budapest. Further she continued her job as designer engineer at firm KEVITERV in city Miskolc. In her working experiments she met with the problems of productions and technologies

of ceramic items at the porcelain manufactory HOLLHZA in 1987. Since then she has a wide range experiments in examination, research and development of new material compositions and

technologies both of traditional and high-tech structural ceramics as well as of ceramic matrix composites. The research works of Ludmilla N. Gmze are presented in several research reports,

conference publications and 5 scientific articles in different German and Hungarian journals.

98 | ptanyagptanyag 2010/4 62. vf. 4. szm

1. IntroductionIn the last 1520 years scientists, engineers and experts

working in laboratories of universities and research institutes or in ceramic manufactory plants have been engaged in development of more effi cient ceramic materials and items for diff erent industrial purposes [14]. Th e sophisticated industry and technology [57] require higher and higher assumption against to mechanical properties, such as hardness [813], strength [1420], wear resistance [2124], toughness [25, 26] and dynamic strength [2729]. Till today several types of ceramic materials and ceramic matrix composites (CMC) are develop with excellent mechanical properties, with high values of mechanical strength and hardness, but most of these materials have microstructures with relatively large crystals, having high rigidness and strong inclination to nick, pitting and rigid fractures. Generally materials with these kind of crystal structures do not have required dynamic strength, and they are not suitable for collisions with other materials and bodies under high speeds. Because of this substantial research has been done in ceramic industry to reduce grain size [3034] aiming to increase the above favourable mechanical properties. However to increase mechanical properties the authors oft en use a simultaneous pressure during sintering applying hot isostatic pressing sintering [20, 33, 35] or spark plasma sintering [36, 37], as presence of pore in the ceramic structure results a signifi cant decrease in its mechanical strength. To obtain high density alumina-zirconia ceramics Wang, Huang and Wu [38] used two-step sintering process, and by Hernndez, Torre and R. Rangel [39] Al2O3 matrix cermets were produced from mechanically mixed powders containing Al, Fe and Ti metals as reinforcements.

Examining the material structure and excellent mechanical properties of SiAlON ceramic composites the advantages of hetero-modulus materials rst was described by German scientist Dr. Hasselman and his co-authors [40] in early of 1980s. The values of Youngs modulus and melting temperatures of advance materials, metal alloys and ceramics (Fig. 1.) was introduced by Igor Shabalin [41] as CE6 Session chair in Symposium ceramics and Engineering of XIVth International Clay Conference (14 ICC).

Fig. 1. Melting points and elastic modulus of advanced technical materials (Taken from Igor Shabalin, 14-icc, Session CE6)

1. bra Korszer mszaki anyagok olvadspontja s rugalmassgi modulusa

MATERIALS SCIENCE ANYAGTUDOMNY

62. vf. 4. szm 2010/4 ptanyagptanyag | 99

From Fig.1. it is obvious that most of ceramics, borides, nitrides and carbides have both high values of Youngs elastic modulus and melting points. Constructing a new material structure from particles components having different Youngs modulus and melting temperatures a new hybrid material could be create with the following valuable advantages:

high damage tolerance, ability to absorb and dissipate the elastic energy during crack propagation,good thermal shock resistance.

Understanding the advantages of hetero-modulus materials new corundum matrix ceramic composites reinforced with Si3N4, -Si3N4, Si2ON2, SiAlON, AlN and 3Al2O32SiO2 particles were successfully developed by the authors [27, 29, 42]. In this work our aims are the following:

understand the mechanical behaviour and properties of hetero-modulus, hetero-viscous complex materials and create their rheo-mechanical model,describe mathematically the mechanical stress development and relaxation during and after high speed collision in this kind of complex materials.

2. Materials and experimental proceduresThe high speed collision process and energy engorgement

through fractures of traditional and hetero-modulus ceramics were already described in details by authors in works [27, 32, 42]. The thermic part of collision energy also was described in the above works and in [29], but there is no works in accordance to high speed collision behaviour of hetero-modulus and hetero-viscous complex and hybrid materials in spite of their following advantages are obvious:

high damage tolerance, higher deformation tolerance, ability to absorb and dissipate the collision energy, relax by time mechanical stress developed in body during high speed collisions.

The mechanical model of complex material structures completed from particles having different values of elastic modulus and viscosity could be modelled by Fig. 2.

To achieve this kind of mechanical model with several Youngs modulus, plasticity and viscosity, our high purity Al2O3 powder was polluted and mixed with submicron particles of SiO2, Si3N4, SiAlON, AlN, Tl2O3 and other oxides and elements. This new material composition was milled in planetary-ball mill through several hours, and nally a powder mix containing 92 m% of Al2O3 was got. This powder mix were compacted uni-axially, using high speed ying punches with high kinetic energy by principle as shown in Fig. 3.

Fig. 3. Principle of compacting specimens under high speed ying punches with high kinetic energy

3. bra A nagy kinetikai energij sajtols elve nagy sebessg repl prs-szerszmmal

There are several methods are used to develop SiAlON particles and transform -Si3N4 into -Si3N4, but all of them used sintering temperatures much about 1700 C or hot pressing at 1800 C under pressure of 23 MPa or more [4347]. In our case we used multi-steps sintering technology processes in which the compacted specimens rst were pre-sintered in nitrogen (N2) atmosphere under special ring curves. Due to phase transformation and recrystallization occurred during the following steps of sintering a new hetero-modulus and hetero-viscous corundum matrix composite (CMC) was developed reinforced with micron and submicron whiskers, nano-particles and viscous glass-like phases as it is shown in Fig. 4.

Fig. 2. Mechanical model of hetero-modulus, hetero-viscous complex materials a11an1 deformations of elastic particles; a12an2 deformation of viscous-plastic particles; a13an3 deformation of viscous-elastic particles; E11En1 Youngs modulus of Hooke particles; E12En2 Youngs modulus of viscous-elastic particles; F1Fn forces on material particles; 11 n1 - viscosity of viscous-plastic particles; 12 n2 viscosity of viscous-elastic particles; 01 0n static yield stress in viscous-plastic particles; l1ln total deformation of particles

2. bra A hetero-modulus s hetero-viszkozits komplex anyagok mechanikai anyagmodellje



3. Results and discussion The shear stresses developing during high speed collisions

in the above introduced (Fig. 4.) hetero-modulus and hetero-viscous hybrid materials could be described by Eq. 1.

(1)

where: 1, 2 and e: viscosities of elastic-viscous-plastic,

elastic-viscous parts and effective viscosity of the hybrid hetero-modulus and hetero-viscous body,

0 and : static yield point of body and shear stress developed during deformation and destruction in the material,

n and n : stress relaxation time and delay time of elas-tic deformation,

and : rst and second derivatives of shear stresses developed in hetero-modulus and hetero-viscous ceramic and CMC bodies during high speed collision with ying objects.

The effective viscosity of the hetero-modulus and hetero-viscous complex materials could be determined by Eq. 2. as the following:

(2)

where: , and : the rst, second and third derivatives of

deformation-speed gradients.

Involving the following new symbols:

, (3.1)

, (3.2)

, (3.3)

, (3.4)

, (3.5)

Fig. 4. Achieved microstructures aft er sintering 4. bra A szinterels sorn ellltott hibridanyagok mikroszerkezete

the Eq. 1. could be rewrite to the following well known form:

(4)

During the high speed collision (u 1000 m/s) there is no plastic deformation in materials, so D=0 and Eq. 4 could be rewrite as:

(5)

Th e Eq. 5. is well-known as the mathematical equation of damped harmonic oscillation, the solutions of which are the followings:

(6.1)

(6.2)

, (6.3)

where :C 1 and C2 are the constants of integration.

Substitute the above expressions the general equation of shear stress relaxation in hybrid hetero-modulus and hetero-viscous ceramics and CMC aft er high speed collision could be described as:

(7)

Substitute the A, B, C and D with the original material constants the value of the mechanical shear stress developed in hetero-viscous and hetero-modulus particles reinforced corundum matrix composite material during high speed collision and its relaxation mathematically could be described as the following:

(8)

4. Conclusion Understanding the high damage and deformation tolerance

and ability to observe and dissipate the collision energy of hetero-modulus and hetero-viscous submicron and nano-



particle reinforced corundum matrix hybrid ceramics and CMCs, the authors successfully created a rheo-mechanical model (Fig. 2.) and mathematical equation (Eq. 8.) to mechanically characterize such a complex material structures of ceramics and composites.

This kind of mechanical model and mathematical equation can help in development high damage and deformation tolerance complex materials like -Si3N4, -Si3N4, Si2ON2, SiAlON, AlN, 3Al2O32SiO2 submicron and nano-particle and liquid phase particle (glass) reinforced alumina matrix hybrid materials.

Acknowledgement The authors acknowledge to Igrex Ltd. for the technical

support of our research for several years and to young teaching stuff and PhD students of Department of Ceramic and Silicate Engineering at the University of Miskolc (Hungary) for laboratory tests and assistance.

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Mechanikai feszltsgek relaxcija a hetero-modu-lus s hetero-viszkzus komplex kermikbanMechanikai s termikus tulajdonsgukat tekintve a hetero-modulus s hetero-viszkzus komplex anyagok szmos elnnyel rendelkeznek a hagyomnyos kermikkal s kermia mtrix kermikkal szemben. Jelen publikciban a szerzk rszletesen vizsgltk a nagy sebessggel repl fmek s kermiatestek kztti tkzs folyamatt, kln-sen a -Si3N4, -Si3N4, Si2ON2, SiAlON s 3Al2O32SiO2 szubmik-ron s nanoszemcskkel erstett alumnium mtrix hibrid anyagokra s azok reo-mechanikai szerkezetre s tulajdons-gaira. Megrtve a nagy sebessg tkzsek folyamatt, vala-mint az ilyen hibrid anyagok anyagszerkezete s reolgiai tu-lajdonsgai kztti kapcsolatokat, jelen munkban a szerzk lerjk az -Si3N4, -Si3N4, Si2ON2, SiAlON s 3Al2O32SiO2 erstett alumnium-oxid mtrix kermia-kompozitokban nagy sebessg tkzsek sorn bred mechanikai nyrfeszlt-sgek egyenlett s azok tkzs utni relaxcijt. A vizsglt korund mtrix komplex anyagok nagy sebessggel trtn tkzst s annak energiaelnyerst a szerzk a [27, 29, 42] munkkban is mr ismertettk rszletesen. Jelen vizsglatok sorn a szerzk Scanning elektronmikroszkpot, rntgendif-frakcis kszlket s energiadiszperz spektromtert alkal-maztak. Az eredmnyek feldolgozshoz s kirtkelshez a digitlis kpelemzs mdszert hasznltk.Kulcsszavak: feszltsg-relaxci, hibrid anyagok, kplkeny-sg, kermik, kompozitok, rugalmassg, viszkozits

Ref.:Lszl A. Gmze Ludmilla N. Gmze: Mechanical stress relaxation

in hetero-modulus, hetero-viscous complex ceramic materials. ptanyag, 62. vf. 4. szm (2010), 98101. p.


New molecular approach for the simulation of nanoparticle polymer interactions: application to the system formed by a lysophospholipidic micelle and polyacrylic acid

YVES CHAPRON Alpine Institute of Environmental Dynamics [email protected] PORQUET Alpine Institute of Environmental Dynamics, SCHEMA MONTSERRAT FILELLA SCHEMA, Institute F-A Forel [email protected]: 07.04.2010. rkezett: 2010.04.07.

Better understanding of the forces between modified or unmodified nanoparticles would be beneficial for developing new strategies for the production of engineered nanoparticle suspensions, as well as for predicting their fate and transport in the environment. Molecular-level simulations, such as Molecular Dynamics can be useful for understanding the interactions between colloidal nanoparticles, but simulations of very large systems are constrained by the long calculation times and require enormous computer resources. A new computation approach that combines series of cycles of Rigid Body Dynamics and Molecular Dynamics has been applied to the study of the interaction of a lysophospholipidic micelle with polyacrylic acid. The results obtained show that the method makes it possible to reach a stationary interaction structure quite rapidly. The method is ready to be applied to the study of the interaction of a wide range of nanoparticles of industrial, environmental or biological interest via a widely-used and freely-accessible computer code.Keywords: nanoparticle, micelle, polyacrilic acid, lysophospholipidic micelle, rigid body dynamics, molecular dynamics

Yves CHAPRONreceived his Doctorat dEtat s Sciences Physiques from the University of Paris in

1970 (~PhD with 2 thesis). Scientist at Atomic Energy Authority (CEA) 1963-1999, former

professor at the Ecole Centrale de Paris and leader of the Modelisation Biophysics Group at

CEA/Grenoble. He worked on nuclear reactor physics, radioprotection, aerothermochemistry,

electrochemistry (pioneering in pulse polarography). Later, on biophysics on vision, electrophysiology, pioneering in patch-clamp & ionic channel of cell membrane. Author of 100 communications (articles), movies and patents. Since 1999 president of the Alpine

Institute of Environmental Dynamics (AIED). The AIED is dedicated to the study of the molecular biogeochemistry of waters, soils and materials.

Alain PORQUET received his PhD in Theoretical and Computational

Chemistry from the University of Strasbourg in 1997. After the PhD thesis, he became research

associate at the universities of Lausanne and Geneva. He has worked in molecular dynamic

simulations of phospholipids bilayers, theoretic calculations of aqua-complexes. He has created

a program to generate molecular structures randomly to the study humic substances.

Montserrat FILELLAreceived her PhD in Chemistry from the

University of Barcelona in 1986. She teaches Environmental Chemistry at the University of

Geneva, where she arrived in 1987. Since 2007 she also works in the development of a society

specialised on fundamental research in environmental chemistry in Luxembourg. She is an IUPAC fellow and member of a number of scientific societies. Her main research interests focus on the understanding of the physicochemical processes regulating the behaviour of chemical elements in environmental and biological compartments. The three main axes of her research concern the

study of: colloids in natural waters, natural organic matter and Group 15 elements.

IntroductionTh ere are currently more than 900 products on the market

that contain nanoscale materials, and the development and commercial production of engineered nanoparticles (ENP) is expected to continue to grow rapidly. Many ENP applications (e.g., as composite materials, components of drug delivery agents, etc.) require ENP suspensions that remain stable in polar media such as water or polymeric resins. However, most ENP are strongly hydrophobic and bare ENP minimize their surface free energy by forming settleable aggregates in solution. To prepare uniform, well-dispersed mixtures, the ENPs exterior surface needs to be modifi ed. Two diff erent methods have been used to stabilize colloidal nanoparticles: either incorporation of functional groups through acid treatment or dispersion by surfactant or polymer adsorption. Th is means that a better appraisal of the forces between modifi ed or unmodifi ed nanoparticles would help to gain a better understanding of the eff ects of the above mentioned surface modifi cations and develop new strategies for producing ENP suspensions. Moreover, the aggregation state of ENP also has a strong infl uence on their fate and transport in the environment. Understanding the factors governing the aggregation behavior of ENP on its own and in contact with natural particles, surfaces and organic macromolecules, is a key to evaluating their environmental transport, fate and potential interaction with biological species.

Historically, the Derjaguin-Landau-Verwey-Overbeek (DLVO) theory has been used to describe electrostatic and van der Waals interactions in colloidal systems [1, 2]. However, the

DLVO theory was originally developped for micron-sized colloidal particles and relies on a continuum approximation that may not extend to nanosized objects. Existing opinions on this issue are contradictory up to this point. On the one hand, results from studies where the functional dependence of the aggregation rates on electrolyte concentration has been measured show that the behavior of nanoparticles follows the qualitative predictions of the DLVO theory in regard to the eff ect of counterion concentration and valence [313]. However, experiments in the literature show that DLVO theory does not always work for micrometer-scale particles at close separations [1416] and modeling studies indicate that the classical theory might have less predictive power for nanocolloids of less than 10 nm in diameter than for larger particles. For instance, according to Fichthorn and Qin [17, 18], forces that are not taken into account by DLVO theory, such as solvation and depletion, could be very important in colloidal nanoparticle systems.

Molecular-level simulations, such as molecular dynamics (MD), can be useful in understanding the interactions between colloidal nanoparticles. Th ese studies can yield atomic-scale detail and they can be used to resolve the origins and magnitudes of forces between those particles. However, MD simulations on very large systems, such as the ones formed by




several interacting nanoparticles, require very large computer resources which make them prohibitive, even with the current calculation capabilities. To overcome this limitation, we have tested a new strategy that combines series of cycles of Rigid Body Dynamics (RBD) and MD. Its application to the study of the interaction of a lysophospholipidic micelle (LPE) with polyacrylic acid (PAA) is presented here. Th e same system constructed with explicit water in a parallelepiped box of minimum size would contain more than 120,000 atoms, implying very long calculation times (i.e., when the number of atoms increases in a system, as a consequence, a quadratical increase in the calculation time is observed). Th e substances used in this study have been chosen only as model compounds with the only objective being to test the new calculation strategy. However, they were not chosen arbitrarily. DLPE is involved in many aspects of living processes [19] and, recently, phospholipid micelles have been used, among other amphilic polymers, to encapsulate hydrophobic quantum dot nanoparticles to create water soluble materials suitable for biological applications [20, 21]. Polyacrylic acid (PAA) has been very oft en chosen as a polymer and polyelectrolyte model substance. A number of industrial processes rely on the use of polyelectrolytes to provoke the fl occulation and/or the dispersion of colloidal particles and, in the past decades, the importance of polymer-colloid interaction has also been widely recognized in soil aggregation and pollutant transport in natural waters.

1. Methods1.1. Computational methods1.1.1. Molecular Dynamics simulations

In MD, the Newtonian equations of motion are integrated to make it possible to follow the displacement of particles over a certain period of time. Th is procedure allows the phase space to be sampled and produces a physical dynamic trajectory that permits temporal analysis. MD simulations were performed using the following representation of potential energy:

(1)

where (i) bond stretching and valence angle deformation are represented by an harmonic potential where Kr and K are the constant forces and req and eq are reference values; (ii) a torsional term, defi ned by a set of Vn, n and parameters, is associated with the dihedral angles; (iii) the non-bonded interactions are split up into Van der Waals interactions, represented by a Lennard-Jones potential defi ned by parameters Aij and Bij, and electrostatic interactions modelled by a Coulombic potential. Electrostatic and van der Waals interactions are only calculated between atoms in diff erent molecules or for atoms in the same molecule separated by at least three bonds. MD calculations have been performed using XPLOR [22, 23]. Th e united-atoms (UA) approach has been used in the calculations. UA force fi elds for MD simulations provide a higher computational effi ciency with little sacrifi ce in accuracy when compared to

all-atom force fi elds, especially in aliphatic chain simulations where very few specifi c interactions exist [24].

1.1.2. Rigid Body simulationsRigid Body (RB) dynamics solves Newton equations of

motion for rigid collections of atoms. Atoms are grouped into rigid groups, the motion of which is determined by summing the forces acting on all elements of a group and integrating the RB equations of motion. Th e XPLOR implementation of RB dynamics follows the algorithm described by Head-Gordon and Brooks [25]. Th is algorithm treats each group as a continuous mass dislocated at the center-of-mass position and characterized by its inertia tensor. Only the non-bonded interactions are computed as RB dynamics energy interactions. However, all atoms are taken into account for the calculation of the general energy. Th e theoretical details are can be found in the XPLOR manual ([22], pages 136140).

1.2. Choice of the polymer and micelle modelsPolyacrylic acid (PAA) monomers were simulated using

a united-atom (UA) approach. Other parameters needed for the UA model were the standard parameters proposed by the Charmm/XPLOR force fi eld for united atoms [27]. Table 1. shows the atomic charges of the protoned PAA polymer chains used in the MD simulations.

Th e lysophosphatidylethanolamine (LPE) monomer was derived from the crystal structure of dilauryl phosphati-dylethanolamine (DLPE) [28] by replacing the fatty acid substituent of the central glycerol oxygen with a hydroxyl group. Atomic charges were computed with semi-empirical quantum chemistry [26]. Th ey are shown in Figure 1. Th e Kerubin program [29] was used to build the micelle from the LPE monomers.

CH3 tail CH2 any other CH2

CH C in CO O H in HO

-0.35 -0.35 0.15 -0.15 0.16 -0.40 0.64

Table 1. Atomic charges of the protonated PAA polymer chains used in the MD simulations

1. tblzat MD szimulciban hasznlt protonlt PAA polimer lncok atomtltsei

Fig. 1. Formula and atomic charges of the lysophosphatidylethanolamine (LPE) monomers used in the MD simulations

1. bra Az MD szimulcikban vizsglt lizofatidil-etanolamin (LPE) monomerek sszegkplete s atomtltsei



2. Results and discussionA PAA polymer chain of 40 monomers (330 atoms), all with

trans-conformation, was used to create the initial structure of the complex. Th is polymer chain was immerged in a periodic box of 6516 water molecules ( = 1) and simulated by MD with XPLOR using the UA model for 10 ps. Th e water molecules of the fi rst hydration shell of the polymer chain (258 water molecules) were kept for later in the simulation of the interaction between the polymer and the micelle.

(a)

(b) Fig. 2. Longitudinal (a) and cross-section (b) snapshots of the hydrated polyacrylic

acid (PAA) polymer build with 40 monomers 2. bra A 40 monomerbl ll hidratlt poliakril sav hosszmenti (a) s keresztmet-

szeti (b) kpe

Figure 2. shows snapshots of the hydrated PAA polymer. Th e simulated PAA has the following dimensions: mean diameter ~ 8-9 , hydrated mean diameter = 33 , length = 78.6 , hydrated length = 105 .

A non-charged and equilibrated micelle composed of 56 LPE monomers (2441 atoms) was built with the Kerubin program. Th e cohesion of the micellar structures is partly due to the interactions between the polar heads of the phospholipid chains of the micelle and water molecules in the fi rst hydration shells. Th us the introduction of explicit water molecules ( = 1) around the micelles is crucial in order to maintain this cohesion during the MD simulations. For this reason, the LPE micelle was equilibrated by 0.1 ps of MD simulation in a spherical box of 2784 water molecules without periodicity. Only 2441 water molecules were kept to hydrate the micelle in further simulations.

Figure 3. shows snapshots of diff erent steps in the process of building the LPE micelle. Th e simulated micelle has the following dimensions: mean diameter (from opposite N atoms) = 53 , hydrated mean diameter (from opposite N atoms) = 62 . Slightly lower diameters are obtained if the distance from opposite P atoms is measured instead. In this case, mean diameter = 50 , hydrated mean diameter = 61 .

(a)

(b)

(c) Fig. 3. Snapshots showing diff erent steps in the process of building the LPE micelle:

(a) fi rst micelle built up with Kerubin, (b) fi rst minimisation of the LPE, (c) micelle

3. bra Az LPE micella felplsnek klnbz lpseit bemutat kpek (a) az els micella felplse Kerubin-nel, (b) az LPE els minimalizldsa, (c) a micella

For the RB simulation, two groups of atoms were defi ned: the hydrated micelle and the hydrated polymer chain. Th e polymer chain-micelle system included 10 011 atoms. To equilibrate the system, the procedure alternated between RB simulation phases, to displace the micelle relatively to the polymer chain (water = 80), and MD simulation phases, to re-equilibrate the water molecules. In order to reduce calculation times, all the atoms of the micelle and of the polymer chain are frozen during each MD phase without modifying the positions of the dry parts of each rigid body obtained in the previous RBD cycle.



Diff erent time step values were tested with two temperature coupling modes [30]. Th e Langevin method was opted for, since the Berendsen coupling method induced too many temperature fl uctuations. Integration times ranging from 1 to 15 fs were tested using this method, and an optimum integration time of 5 fs was fi nally chosen. Th e alternating RB/MD cycles lasted for 10 ps and included four successive series of 2.5 ps RB and 50 fs MD with an integration step of 1 fs. Figure 4a shows temperature fl uctuations with a Langevin thermal bath ( = 30, T = 300 K), RBD only. Temperature fl uctuations during four successive cycles of RBD and MD calculations are shown in Figure 4b; they refl ect water reorganisation needed during the short MD runs.

(a)

(b) Fig. 4. (a) Temperature fl uctuations with a Langevin thermal bath ( = 30, T = 300

K) RBD only. (b) Temperature fl uctuations during four successive cycles of RBD and MD calculations

4. bra (a) Hmrskletingadozsok a Langevin hfrdben (=30, T=300 K) csak RGB-vel szmolva, (b) Hmrskletingadozsok RBD s MD mdszerek kombincijval szmolva, ngy egymst kvet ciklusban

Quick equilibration of the interaction energies was observed by using the RB/MD method. Figure 5. shows the evolution of the non-bonded interaction energies, van der Waals and electrostatic, between the LPE micelle and the PAA polymer chain during four mixing RBD and MD cycles. Th e initial repulsion, resulting from the arbitrary initial position of the two objects, evolves quite rapidly to a thermodynamic stabilisation. Th e MD trajectory Van der Waals energy decreases from +2500 to -1000 kcal.mol-1, thus showing good contact reorganisation of the system confi guration. Simultaneously, the MD trajectory electrostatic energy relaxes from an initial value of -500 kcal.mol-1 to a more equilibrated value of -100 kcal.mol-1. Th e evolution of the non-bonded atomic interactions and the temperature fl uctuations during the simulations clearly shows that water reorganised itself during MD phases (50 fs).

(a)

(b) Fig. 5. Evolution with time of the non-bonded interaction energies between the LPE

micelle and the PAA polymer chain during (a) the initial four successive cycles of RBD and MD calculations, (b) the complete simulation (40 ps) van der Waals interactions: ; electrostatic interactions: . RBD (2.5 ps) and MD (50 fs) steps are clearly indicated in (a)

5. bra Az LPE micella s a PAA polimer kztti nem-kt klcsnhatsok ener-gijnak idbeli alakulsa (a) az RBD s MD mdszerek kombincijval szmolva, az els ngy egymst kvet ciklusban, (b) a van der Waals klcsnhatsok teljes szimulcija (40 ps), ; elektrosztatikus klcsnhatsok, . RBD (2,5 ps) s MD (50 fs) lpsek jl lthatk az (a) brn

Th e evolution of the distances from the head and the tail of the PAA monomer to the LPE micelle center is shown in Figure 6. Interestingly, the head and the tail of the PAA position themselves at a similar distance from the micelle center at the end of the equilibration. Figure 7. shows the evolution of the angles PAA head micelle tail PAA (larger angle) and the one formed by two oxygen atoms of the residue 10 of the PAA with the micelle (smaller angle). A correlation between the two angles is observed, as if the micelle rolling over the polymer perturbated them. Finally, a split snapshot of the initial structure of the PAA polymer chain - LPE micelle complex is shown in Figure 8.

Fig. 6. Evolution with time of the distances from the head () and the tail () of the PAA polymer chain to the LPE micelle center during four successive cycles of RBD and MD calculations

6. bra LPE micella kzppontja s a PAA polimer lnc fej (), illetve oldal () rsze kztti tvosg vltozsa az id fggvnyben az RBD s MD szmtsok ngy egymst kvet ciklusban



Fig. 7. Evolution of the angles formed by head of the PAA micelle tail PAA (big angle) and the OX10 PAA micelle OY10 PAA (small angle)

7. bra A PAA fejrsze - micella - PAA oldalrsze kztti szg (nagy szg) s az OX10 PAA - micella - OY10 PAA kztti szg (kis szg) alakulsa

Fig. 8. Snapshot of the initial structure of the PAA polymer chain - LPE micelle complex. At the left hand-side the water molecules are represented in wireframe to clearly show the polymer chain and the micelle monomers. At the right hand-side the water molecules are represented in CPK to show the hydration shell

8. bra A PAA polimer lnc - LPE micella komplex kezdeti szerkezetnek kpe. A bal oldalon a vzmolekulkat drtvzzal brzoltuk azrt, hogy a polimer lnc s a micella monomerek jl lthatk legyenek. A jobb oldalon a vzmolekulk CPK-ban lthatk a hidratcis burok bemutatsra

In the procedure explained above, the water was kept at 80, so that the electrostatic energy was screened and a reduced number of water molecules moved simultaneously during the MD steps. Th is procedure has no eff ect on the van der Waals energies. Once the dynamic equilibrium was reached, water was allowed to reorganise by performing some calculation cycles with implicit water in all the space for RBD and explicit water (water = 1) for MD. Since the initial position was not far from the fi nal one, spatial and energetic convergences were very rapid. Kinetic parameters associated with such quick processes are not accessible experimentally, but are easy to determine from the results obtained. In the study system, a half time of about 3 ps was calculated. Th e eff ect of the sampling cut-off on the fi nal result was also tested and the smallest value (19 ) for which results were not aff ected by the choice was used.

Th e Constraint Interaction Energy (CIE) and the distance between the two objects were computed at the end of the simulation. Th e corresponding value of the van der Waals energy (of CIE) between the PAA polymer chain and the LPE micelle (-10.9 kcal.mol-1) and the distance between the two objects obtained from this calculation (10.6 ) can be used to estimate the value of the Hamaker constant [31]. Th e so-called Hamaker-De Boer theory is oft en used to compute van der Waals interactions between macrobodies. Th is theory is an

approximate treatment in which the total attraction energy is obtained by pair-wise summation of London-Van der Waals energies between all molecules of the interacting bodies. Retardation is disregarded. A detailed description as well as a discussion of its limitations can be found in Lyklema [32].

Van der Waals energies and the corresponding Hamaker constants have been computed in the Hamaker-De Boer approximation for a host of geometries but expressions for many geometries are still not well-established. Th e system being studied can be approximated by the expression for the interaction of a sphere with an infi nite plane [32]:

[2]

where: EvdW is the van der Waals energy (J), AH is the Hamaker constant (J), rs the radius of the micelle () and h the minimum distance between the micelle and the polymer (). Th is gives a value of 4.0x10-19 J for the Hamaker constant. However, according to [33], this approximation can only be applied if the ratio between the distance h and the radius of the sphere rs is 1 (0.4 in our case) and the ratio of the cylinder radius to the sphere radius is larger than 10, regardless of the ratio of the cylinder length to its radius. Th e second condition is not fulfi lled in our case. Th us, the value calculated here for the Hamaker constant can only be considered to be an approximation. Th e value obtained is close, but slightly higher, than the range of values reported for protein-protein interactions in water (1.0x10-20 3.6x10-20 J) [34-40]. It should be mentioned that Rosenfeld and Wasan [41] have put forward an expression for the interaction between a fi nite cylinder and a sphere. However, we found an error in relation to the integration domain of their expression when we tried to implement it in Mathcad. Since the objective of this study was to show the capabilities of the modeling approach rather than to calculate an accurate value of the Hamaker constant for the given model system, no further eff ort was devoted to correcting the equation.

3. ConclusionsTh e results obtained show that the combination of RBD and

MD in an explicitly partially hydrated system is a powerful tool for studying interactions between heterogeneous systems because they make it possible to perform complex calculations while keeping calculation times reasonable. It should be pointed out that the same system constructed with explicit water in a parallelepiped box of minimum size contains more than 120,000 atoms. Although it can be solved by using computer codes such as XPLOR [22, 23], VMD [42] and NAMD [43], the high number of atoms present makes the calculation long and the calculation procedure cumbersome because it requires fi les of structures and atom coordinates be written in hexadecimal notation and the calculation be run by using it.

AcknowledgementsWe are grateful to Eric Desrues for sharing his mathematical

insight with us. His help in analysing the expression proposed by Rosenfeld and Wasan was invaluable.



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Nanorszecske-polimer klcsnhatsok j molekulris megkzeltse: alkalmazsi plda lizofoszfolipid micella-poliakrilsav rendszerre A mdostatlan vagy mdostott nanorszecskk kztti erk jobb megrtse elnysen jrulhat hozz olyan j stratgik kifejlesztshez, amelyek egyrszt alkalmasak elre tervezett tulajdonsg nanorszecske szuszpenzk ellltsra, ms-rszt ezen anyagok krnyezeti mozgsnak s lebomlsnak nyomonkvetsre. A molekula szint szimulcik, kztk a Molekula Dinamika (MD), nagyban elsegthetik a kol-loid nano rszecskk kztti klcsnhatsok rtelmezst. Ugyanakkor e mdszerekkel nagyon nagy rendszerek nem modellezhetk, klnleges szmtstechnikai httrignyk, s a szmtsokhoz szksges hossz id miatt. Kzlem-nynkben egy j, a Merev Testek Dinamikjnak (RBD) s a Molekula Dinamiknak kombinlt ciklusain alapul szmtsi mdszer alkalmazst mutatjuk be lizofoszfolipid micellk-bl s poliakrilsavbl ll rendszerre. Eredmnyeink szerint a mdszerrel viszonylag gyorsan el lehet jutni a stacionrius klcsnhats-szerkezethez. Mdszernk alkalmas lehet kr-nyezeti, vagy biolgiai szempontbl rdekes, legklnflbb nanorszecskk klcsnhatsainak tanulmnyozsra, egy szles krben hasznlatos s szabadon hozzfrhet szmt-gpes program segtsgvel.Kulcsszavak: nanorszecske, micella, poliakril sav, lizofoszfo-lipid micella, merev test dinamika, molekula dinamika

Ref.:Yves Chapron Alain Porquet Montserrat Filella: New molecular

approach for the simulation of nanoparticle polymer interactions: application to the system formed by a lysophospholipidic micelle and polyacrylic acid. ptanyag, 62. vf. 4. szm (2010), 102107. p.

SZERKESZTBIZOTTSGI MEGJEGYZSAz utbbi kt-hrom vben a korszer kermia s szilikt anyag rendszerek terletn egyre nagyobb szerephez jut a komplex, szer ves s szervetlen anyagokat egyarnt tartal-maz hibridanyagok kutatsa s fejlesztse. Ezt jl tkrzi, hogy a 2010. november 1418. kztt Oszakban megrendezett 3. Nemzetkzi Kermia Kongresszuson (ICC3) az eladsok szmt tekintve a hibrid s nano-szerkezet anyagok kutatsa terletn elrt j eredmnyeket bemutat 5. Szimpzium a har-madik legnpesebb szekcija volt a rendezvnynek. Ettl tbb eladst s posztert Japnban csak a korszer elektrotechnikai kermia szekci (Szimpzium 6.) s az lenjr mszaki kermik s kompozitok (Szimpzium 14.) tudott felvonultatni. Lapunkban az Yves Chapron, Alain Porquet s Montserrat Filella szerzk ltal fentiekben kzlt cikkel szeretnnk az els lpst megten-ni a hibrid anyagok kutatsa, publiklsa fel. Ezek az anyagok gyakran nem csak szerves s szervetlen anyagok szimbizisbl plnek fel, de olykor egyidejleg tartalmaznak vagy tartalmaz-hatnak a szilrd kermia szemcsk s kristlyok mellett szerves folyadkokat s/vagy gz halmazllapot rszecskket.

EGYESLETI S SZAKHREK SOCIETY AND PROFESSIONAL NEWS


XXV. Tgls NapokTTH-ASZTALOS RKA

A Sziliktipari Tudomnyos Egyeslet s a Magyar Tgls Szvetsg kzs szervezsben idn 25. alkalommal kerlt megrendezsre a hagyomnyos vi konferencia. A rendezvny helyszne ezttal Lenti-Gosztola volt.

A konferencit oktber 28-n Kiss Rbert, az SZTE Tgla s Cserp Szakosztlynak elnke nyitotta meg.

Az els eladst Horvth Sndor, az MI Nonprofi t Kft . vezrigazgat-helyettese tartotta Az j ptsi termk rendelet-re (CPR) val felkszlssel kapcsolatban. Az ptsi termkek megfelelsgt jelenti egyrszt, ha ptsi clra alkalmas (ha a gyrt utastsnak s a mszaki tervnek megfelel bep-ts esetn az ptmny kielgti az alapvet kvetelmnyeket); msrszt, ha megfelelsgi igazolssal rendelkezik (szllti megfelelsgi nyilatkozat, CE jells). Forgalomba hozatalhoz megfelelsgre, megfelelsgi igazolsra van szksg. A jelen-leg is rvnyben lev szablyozs, az ptsi Termk Irnyelv (CPD) bonyolult, kltsges s hosszadalmas eljrst takar. Az j ptsi Termk Rendelet (CPR) ezzel szemben egyszer, hiteles, tlthat s olcs lesz; irnyelv helyett rendelet, megfelelsgi igazols helyett teljestmny nyilatkozat. Vltozs a kvetkez terleteken vrhat elssorban: az alapvet kvetelmnyek sz mnak nvekedse, a megfelelsg-rtkelsi eljrsok sz-mnak mrskldse, a mikrovllal kozsok specilis keze lse, a CE jells elrsnek pontostsa, az rtkelseknl a szmtsi mdszerek preferlsa, az intzmnyrendszerben j szereplk megjelense. Az j rendelet hatsa az ptsi s ptanyag gyrt piacra nzve vrhatan volumenvltozsokban, az export-import arnyok, a minsgi mutatk, a munkaerigny, a pro-fi tabilits, valamint a verseny kpessg vltozsban fi gyelhet majd meg. Az j rendelet vrhatan hatssal lesz a kormnyzati intzmnyrendszerre, az ptsi termkek gyrtira, az ptsi termkek forgalmazira, a tervezkre, a kivitelez ptiparra, az pttetkre (felhasznlkra), a kijellt szervezetekre s a jvhagy szervezetekre.

Ezutn Lahki Katalin s Veresn Szcs va, a Nemzeti Fo-gyasztvdelmi Hatsg vezet ftancsosai tartottak eladst az NFH piacfelgyeleti tevkenysgrl. A forgalmazott ter-mkekkel kapcsolatban egyrszt a gyrt felelssge az ru biz-tonsgrl gondoskodni, msrszt a forgalmaz nem hozhat forgalomba olyan rut, amelyrl tudja, vagy a rendelkezsre ll tjkoztats vagy szakmai ismeret alapjn tudnia kellene, hogy az ru nem biztonsgos. Az NFH a forgalmazott termkeket kt flekppen ellenrzi. Egyrszt az rusts helysznn, ahol sor kerl az zlet mkdsnek s a forgalmazott termkeknek az ellenrzsre, msrszt mintavtelt kveten sajt laborat-riumban ellenrzi a termk jellemzit. A forgalmazs krl-mnyeinek ellenrzsekor az albbi szempontokat vizsgljk: mkdsi engedly zletben trtn elhelyezse, az ru erede-tt igazol bizonylat meglte, nyitvatartsi id, az rfeltntets meglte s megfelelsge, nyugtaadsi ktelezettsg, a vsrlk knyve s a panaszfrumokrl szl tjkoztats.

A fogyasztvdelemrl szl 1997. vi CLV trvny 13. -a alapjn azok a termkek, amelyekre vonatkozan jogszably megfelelsgrtkelsi ktelezettsget r el, csak az elrt md

sze rinti megfelelsgi tanstvnnyal, megfelelsgi nyilatkozat-tal, illetve megfelelsgi jellssel egytt forgalmazhatk.

A BM-GKM-KvVM 3/2003.(I.25.), az ptsi termkek mszaki kvetelmnyeinek, megfelelsg igazolsnak, va-lamint forgalomba hozatalnak s felhasznlsnak rszletes szablyairl szl egyttes rendelete alapjn a szllti megfelelsgi nyilatkozat tartalma a kvetkez: az ptsi termk szlltjnak (gyrtjnak, forgalmazjnak) neve, azonost jele s cme; az ptsi termk rendeltetsi clja s azonostshoz szksges adatai, a gyrts dtuma, a termk tpusa; azon kijellt (vizsgl, vagy tanst) szervezetek meg-nevezse, azonostsi szma, amelyek tanstvnyai alapjn a megfelelsgi nyilatkozat kiadsra kerlt; azon mszaki speci-fi kcik felsorolsa, amelyeknek az ptsi termk vizsglat-tal igazoltan megfelel; a megfelelsgi nyilatkozat rvnyes-sgi ideje; a szllt (gyrt, vagy forgalmaz) megfelelsgi nyi latkozat alrsra felhatalmazott kpviseljnek neve s beosz tsa; a megfelelsgi nyilatkozat azonost szma, a ki-ads dtuma, a killt cgszer alrsa.

Az NFH az ptanyagok terletn a kvetkez termk-csoportokat ellenrizte 2009-ben: cement, habarcs, betonacl, falazelem, tetfed anyag, transzportbeton, valamint h- s vzszigetel anyagok; 2010-ben: ptsi fatermkek, bdo-gos termkek, raditorok, ivvzzel rintkez csvezetkek s ivvzzel nem rintkez csvezetkek.

Bfebdet kveten Dr. Kiss Tibor, a PTE Kzgazdasg-tudomnyi Kar docense tartott eladst Kk gazdasg az p-tszetben cmmel. Az kolgiai rendszereken alapul gazdasg megteremtse megolds lehet a vilgszerte tapasztalhat gaz-dasgi s kolgiai vlsgra. Clja, hogy az ember legfonto-sabb alapszksgleteinek ivvz, lelem, munka s menedk kielgtst a gazdasg a termszetben tallhat eszkzk, krnyezeti felttelek segtsgvel biztostsa, az erforrsok kimertse nlkl. A tpanyagok s az energia folyamatos vissza forgatsval a bioszfra mkdsnek krforgshoz hasonlan elkerlhet a hulladk keletkezse.

A kk gazdasg koncepcijnak alapjt a termszet, a fi zikai trvnyek adjk. Ezt felhasznlva merlt fel pldul a selyemmel helyettesthet titn, a gombatermesztshez hasznlhat kv-zacc, a szlenergibl, emberi testbl nyerhet elektromos ener-gia tlete, melyek nmelyike mr a gyakorlatban is mkdik, s alapja lehet az j gazdasgi modellnek. A mgttes erk, a fi zikbl kvetkez rendszerfelttelek fi gyelembe vtelvel mkd kk gazdasg fenntarthatsgot eredmnyez azzal, hogy cskkenti, vagy kikszbli az energiabefektetst, a hul-ladkot, a nem hatkony anyaghasznlatot s ezek kltsgeit is.

Az j gazdasgi koncepci alapjait Gnter Pauli Kk Gaz-dasg cm knyvben rja le. Pauli azt lltja, ha a bemutatott 100 mdszert alkalmaznk a klnbz ipargakban, azzal 10 v alatt 100 milli munkahely teremtdne vilgszerte, a tbb-

SOCIETY AND PROFESSIONAL NEWS EGYESLETI S SZAKHREK


szrs innovcik tbbszrs kszpnzforgalmat generlnnak s az sszes alapvet szksgletre megoldst hoznnak, emel-lett az kolgiai problmk is megsznnnek.

Ezutn Dr. Gmze A. Lszl, a Miskolci Egyetem Kermia- s Sziliktmrnki Tanszknek tanszkvezetje beszlt az Anyag vizsglatok jelentsgrl a tgla- s cserpipar szmra. Az anyagvizsglatok kiemelked fontossgak s jelentsgek az olyan hagyomnyos termkek gyrtsnl is, mint a kermia tgla s tetcserp. Az anyagvizsglat irnyulhat svnyi s/vagy kmiai sszettelre; anyagszerkezet (mikro, makro, nano) feltrsra; fi zikai, kmiai, mechanikai s termikus tulajdon-sgok megismersre, javtsra. A technolgia helye szerint nyersanyagokra, alap- s segdanyagokra; nyersgyrtmnyok tulajdonsgaira; getett ksztermk minsgre, tulajdons-gaira; adott technolgiai berendezs, vagy mvelet valamelyik anyagtulajdonsgra gyakorolt hatsnak feltrsra.

A nyersanyag vizsglatok sorn sor kerl az svnyi sszet-tel (rntgenvizsglat), a szemcseszerkezet (granulometriai vizs-glat), a fajlagos fellet (BET, Langmuir vizsglatok), a mecha-nikai tulajdonsgok (reolgiai, tmrdsi s alakthatsgi vizsglatok) s a termikus tulajdonsgok (termoanalitikai s hevtmikroszkpos vizsglatok) meghatrozsra. A nyersgyrt-mnyok alak- s formatartssgt (geometriai s mechanikai vizs-glatok), nedvessgtartalmt s szrthatsgt (Bourry-Morozov diagramok felvtele, szradsi rzkenysg, szradsi zsugorods meghatrozsa), anyagszerkezett (szemcse- s prusszerkezet, makro- s mikrorepedsek meghatrozsa optikai s scanning elektronmikroszkppal) vizsgljk. Az getett ksztermkek esetben pedig ellenrzik azok geometriai mreteit, mechanikai (nyom- s hajltszilrdsg meghatrozsa), makroszerkeze-ti (prusszerkezet, vzfelvtel s fagyllsg meghatrozsa), mikro- s nanoszerkezeti (SEM), svnyszerkezeti- s kmiai (XRD a hkezels sorn lejtszdott fzistalakulsok, elegykris-tly kpzdsek feltrsra) s nedvestsi (hevtmikroszkpia) vizs glatokat vgeznek.

A konferencia zrsaknt Stark Lszl fnykpes besz-molt tartott a Mlyi Tgla Kft . gyrban 2009-ben trtnt modernizcirl, mely a Mlyi Tglagyr trtnetnek leg-nagyobb rekonstrukcija volt. A gyrtsi technolgia teljes automatizlsa sorn j alagtkemence s annak logisztikai rendszere kerlt kialaktsra. Ennek eredmnyknt az itt gyr-

tott termkek emberi kz rintse nlkl, kivl s megbzhat minsgben, jobb htechnikai jellem-zkkel, korszerbb cso-ma golssal kerlnek ki a piacra. A sajt fej lesz-ts PORObrick ter-mk csald vlasztka ki b vlt, a termkpalet-tn meg jelent a 44-es s 25-s ntfderes falaz-tgla. A tglarendszer termkei eurpai szn-vonalak, szi lrdsguk, h-s hang szigetel k-pessgk, tzllsgi tu-

lajdon sguk az elvgzett vizsglatok szerint az elrhet legjobb minstsi kategriba tartoznak.

Az eladsokat kveten a konferencia vendgei erdei nosztal-gia vasutazson vettek rszt Csmdr s Lenti kztt (1. kp). A Csmdri Erdei Vast Magyarorszg leghosszabb (102,9 km hossz) kisvasti hlzata. rdekessge, hogy ennek mindssze a harmadn van szemlyszllts, a forgalom nagy rszt mg ma is a ft szllt tehervonatok jelentik. A hangulatos program utn a rsztvevk megtekintettk a kisvast Lenti llomsp-letben tallhat, Gcsej kincsei, az erd s a fa cm er-dszet-, frszipar- s vasttrtneti killtst.

A kirndulst kveten a vacso-ra keretben Dr. Szpvlgyi Jnos, az SZTE elnke s Kiss Rbert, az SZTE Tgla s Cserp Szakoszt-lynak elnke ksznttte a konferencia rsztvevit a 25. Tg-ls Napok alkalmbl. A vacsora utn vforduls tgla-torta elfogyasztsra kerlt sor (2. kp). Ksbb Kat Aladr, a Ma-gyar Tgls Szvetsg elnke ajndkkal ksznttte a Nagy-kanizsa Tglagyr nyugdjba vonul igazgatjt, Gyuricza Fe-rencet.

Msnap, szakmai program keretben sor kerlt a Creaton Hungary Kft . cserpgyrnak megtekintsre (3. kp). A gyr-ltogats eltt a cserpgyr trtnetrl tartott beszmolt Schmidt Tibor, a Creaton Hungary Kft . gyvezet igazgatja.

Lentiben alaptottk meg az els klfldi CREATON-telephe lyet egy kitn nyersanyag-lelhelyre alapozva, amely kzponti helyet foglal el Magyarorszg, Ausztria, Szlovnia s Horvtorszg fontos piacai szmra. A gyr ptse 2004. mjus 10-n zldmezs beruhzsknt indult. A 2005-ben zembe helyezett I. sz. gyregysgben vente 20 milli hdfark- s hornyolt tetcserepet ksztenek. 2008 tavaszn a msodik, ul-tramodern gyrthe lyet is zembe helyeztk. A II. sz. zemben vente kb. 21,8 milli lapos- s prselt tetcserepet ksztenek, valamint itt gyrtjk a BALANCE s RAPIDO cserpmodellek szleskr tartozkait is.

1 3

2

ANYAGTECHNOLGIA MATERIALS TECHNOLOGY


Az vegszlgyrts optimalizlsnak lehetsges mdszerei

SZEMN JZSEF [email protected]: 2010.08.31. Received: 31.08.2010.

Possible methods of optimising glass fibre production The paper presents the glass fibre production sketchily, the spinner deals with some components of a technique and his interactions in detail. Analyse the viscosity, the temperatures, the spinner forming, the bore diameter, the uptime, the conceptual and practical effects of the glass load, the rev. The glass fibre production formulates proposals optimising his possible methods.Keywords: glassfiber, fiber diameter, spinner, velocity, viscosity, temperature

SZEMN Jzsef (1949) 1973-ban vgzett a Veszprmi

Vegyipari Egyetemen, nehzvegyipari szak, folyamatszablyozs gazaton.

Munkahelyei: Salgtarjni Kohszati zemek, Ngrdi Sznbnyk, Salgtarjni veggyapot

Rt, jelenleg nyugdjas. Publikcii: cikkek az PTANYAG-ban.

BevezetsA sziliktszlas anyagok felhasznlsa napjainkban szles sk-

lt lel fel pldul hszigetels, hangszigetels, szrstechnika, mszertechnika, szloptika, szlersts manyagtermkek stb. A klnbz alkalmazsok egysgesen megkvetelik a sta-bil, homogn szerkezet, kzel azonos tmrj vegszlakat. Dolgozatomban az vegszlak gyrtsval, azon bell is a spin-ner technika nhny sszetevjvel s klcsnhatsaival foglal-kozom.

Az vegszlak gyrtsaAlapveten kt technikja van az vegszl ellltsnak

a szlhzsos s a centrifugs, azaz spinner mdszer. Mind-kt eljrsnl jl nyjthat, homogn veget kell elkszteni, olvasztani s azt eljuttatni a szlazhoz. A szlhzsos md-szernl az olvadt veget vkony furatokon hzzk t, majd felcsvlik. gy ltalban hossz szlakat gyrtanak optikai s mszertechnikai clokra. A centrifugs eljrsnl az olvadt veg az olvasztkemencbl a feederen t egy fell nyitott, forg hengerbe, a spinnerbe folyik. A henger palstjn tbb ezer 0,31 mm tmrj furaton prseldik t az veg a centrifug-lis er hatsra. A kpzdtt egyedi vastag vegszlak olyan hmrskletek, hogy mg tovbb nylnak, vkonyodnak. Ez a technika rvidebb, de vkony szlakat eredmnyez. F gyr-tsi terlet az veggyapot, svnygyapot s a natr vegszl ellltsa. Az veggyapot ksztsnl a megolvasztott, homo-genizlt veg a feeder vgnl egy-egy megfelel lyuktmrj platina testen folyik t a spinnerekbe. Ezeket specilis gzgkkel is melegtik, htik a megfelel hmrskletek biztostsa cl-jbl. Egy msik gzg s terelleveg rendszer elsegti a kpzdtt, viszonylag vastag vegszlak tovbbi nyjtst, a szltmr cskkentst, homogenizlst. A szlak felletre, hre kemnyed specilis ragasztt, gynevezett ktanyagot permeteznek. A kpzdtt szlhalmazt egy alulrl megszvott rcsos szerkezet szlltszalagon gyjtik ssze, ami tovb-btja azt a kikemnyt kemencbe, ahol a termk vastagsga is bellthat. Itt a korbban a szlra szrt ktanyag a h ha-tsra polikondenzldik, s rugalmasan rgzti egymshoz az elemi szlakat. Ezutn automata vgrendszer eltvoltja a nem homogn szleket s a megfelel hosszsg egyedi darabokat alaktja ki. A termket a gyrtsor vgn ltalban automata rendszer csomagolja.

A szlkpzsrlAz olvadt veg az alkalmazott technolgitl, vegsszetteltl

fgg hmrskleten, a platina kifolykon a szlaztrcsba csurog. Viszkozitst az vegalkotk, s a hmrsklet ha-trozza meg. A hmrsklet emelkedsvel exponencilisan cskken az olvadk viszkozitsa [1]. A 3001500 mm tmrj s 30100 mm palstmagassg, palstjn tbb ezer furattal el-ltott forg trcsban, a spinnerben az veget a centrifuglis er a palstra knyszerti. Az als furatokon kifolyik az olva-dk egy rsze, a maradk veg felkszik a palston a kvetkez lyuk sorhoz is s ez a folyamat, addig ismtldik, mg az sszes veg el nem tvozik a lyukakon t. Teht az alkalmazott felt-telek hatsra bell egy egyensly s elkpzelhet, hogy a pa-lst tetejn tallhat lyukakhoz mr nem jut veg, azokon nem folyik t, illetve kevesebb folyik ki az als lyukakon s a palst tetejn felgylemlik, s ott megdermed. Fontos megjegyezni, hogy a szlaztrcsa hmrsklete lyuksorrl lyuksorra vl-tozik. Ez azrt jelents tny, mert az veg viszkozitsa drasz-tikusan emelkedik a hmrsklet cskkensvel [1] s a magas viszkozits nagyobb ellenllst eredmnyez, azaz nehezebben folyik t a furatokon, kevsb nyjthat, formzhat. A lyuka-kon kijutott veg a kifolysi sebessg, a viszkozits s felleti feszltsg hatsra megnylik, vkonyodik, s rosszabb eset-ben elszakad, azaz aprzdik s veggbkk alakul. Az olvadt veg spinner furataibl trtn kifolysi sebessgt a viszkozi-ts, a fordulatszmtl fgg centrifuglis er s a lyuktmr befolysolja.

A magas hmrsklet (9001100 C) vegolvadk ter-mszetesen idvel koptatja a spinner apr furatait, gy azok kibvlnek s a nagyobb nylson tbb veg jut t.

Az elz rvid ismertetbl is ltszik, hogy a homogn megfelelen vkony szl ellltst szmos paramter be-folysolja, s ezeket esetenknt ms-ms hatserssggel kell fi gyelembe venni. A befolysol tnyezk jl szemlltethetk egy a minsgbiztostsban mr klasszikusnak tekinthet eljrssal az Ishikawa ok-hats diagramos (1. bra) feldolgozs-sal [2]. A mdszer kzismert, mr a kzpszint kpzsben is oktatjk s elnye, hogy racionlis sszefggsek trhatk fel vele a min dennapi gyakorlatban is.

A tapasztalati s logikai ton kapott, illetve brzolt befoly-sol tnyezk, okok hatserssgt XY tpus koordinta rend-szerben brzolva a mrhet jellemzknl egyszeren szemll -

MATERIALS TECHNOLOGY ANYAGTECHNOLGIA


tethetjk. Ha a pontsereg valamilyen tendencit kvet, akkor azt szmszersthetjk is pl. regresszis elemzssel. Az gy nyert s bizonytott hatsok mr alkalmasak arra, hogy aktvan beavatkozzunk s irnytsuk a szlkpzs folyamatt.

Munkmban a szlkpzst befolysol, numerikus okozkat gyakorlati tapasztalatok s irodalmi hivatkozsok alapjn vlasztottam ki.

A gyrt rdeke, hogy berendezseit az optimlis maxim-lis hatkonysg kzelben zemeltesse. Ez az vegterhels, a gyrtkapacits s a gp zemidejnek minl nagyobb rtkt kveteli meg. Clszeren ezek hatsait elemzem elszr.

A feldolgozs sorn tendencikat mutatok be, ehhez pedig az egyedi adatok okozta nagymrtk szrdst elkerlend, a mozgtlag mdszerrel nyert simtott rtkeket hasznlom. A mozgtlag mintaszmt egyedi becslsekkel hatroztam meg, ltalban n = 15 30 rtk egyedi adatok mozg tlagaival.

Az zemid hatsaAz ltalnos impresszi az, hogy a szltmr az zemidvel

arnyosan emelkedik (2. bra). Ez sszhangban van azzal a szin-tn gyakorlati tapasztalattal, hogy a spinner furatai kopnak, bvlnek. A feldolgozott adatok hossz, tbb hnapos idszak rtkeit lelik t, gy egy-egy rsztendencia is megfi gyelhet. Ezek az vegsszetevk s vele egytt a viszkozits, a technol-gia, a spinnerek vltozsai, amelyek termszetesen tenden-cikat, pontsrsdseket eredmnyeznek. Ezek nhny ha-tst a ksbbiekben elemzem, mutatom be.

sszessgben megllapthat, hogy a vizsglt ponthalmazra az exponencilis trend illeszkedik a legjobban. Ez egyttal azt is sugallja, hogy a hasznlati id emelkedsvel a szltmr is egyre drasztikusabban n. Viszonylag egyenletes s alacsony

tmrj vegszl gyrtsnl teht gyelni kell arra, hogy a gyrtsoron ne azonos, hanem klnbz zemidej spin-nerek legyenek hasznlatban.

y = 5,5745e0,0002x

R 2 = 0,919

5,15,25,35,45,55,65,75,85,96,06,16,2

0040030020010

zemid ra

szl

tm

r

mic

ron

2. bra Az zemid hatsa a szltmrre Fig. 2. Eff ect of working time for fi ber diameter

Az vegterhels hatsa a szltmrreA klnbz kialakts spinnerek sszehasonltshoz

be kell vezetni egy fajlagos terhels mutatszmot. Ez a mu-tatszm clszeren a furatokon tfoly veg tlagos mennyi-sge, mrtke: gr veg/furat/ra. Az tfoly veg mennyis-gt a furat tmrje, a furat hossza, azaz a palst vastagsga, a furat kikpzse, az veg hmrsklete s viszkozitsa, azaz folykony sga, az veget a furaton thajt centrifuglis er nagysga, azaz a spinner fordulatszma alapveten befolysol-ja. A vizsglt adatokat feldolgozva a 3. bra mutatja be a kap-csolatot a szltmr s a fajlagos terhels kztt.

A legkisebb terhelsi tartomnyban kzel fggetlen a terhelstl a gyrtott vegszl tmrje. A vizsglt tartomny (1830 gr veg/furat/ra) utols negyedben (2730 gr veg/furat/ra) mr nagyobb ingadozsokkal kveti a pontok elhe-lyezkedse az ltalnos trendet, s itt mr jelentsen inhomogn

oxidos sszettel

hmrsklet

viszkozits

mennyisgzemid

feladatok, lers

veg Spinner

anyag, kopsllsg

felleti feszltsgfordulatszm, sebessg

lyukszm, oszlopokban, sorokban

hmrsklet eloszls a spinnerben

mszerezettsg

munkakrlmnyek, kommunikls

lyuktmr, alak, kops

J szl szlterels, gyjts

veg szlazba juttats

Szlaz kialaktsa

kezelhetsg, stabilits

Kezel

veg terhels

fts, hts lehetsgek

hozzrts, kpzettsg

beavatkozsi lehetsgek

mretek: tmr,magassg, vastagsg

ktanyag szrs

fts, hts lehetsgek

1. bra A szlkpzst befolysol tnyezk Ishikawa diagramja Fig. 1. Ishikawa diagram for fi berising



az tmr. A jellemz trend az exponencilis kzeltssel adja a legjobb illeszkedst a pontok kztt. A ler fggvny nagyon jl kzelti a mrt rtkeket, r2 = 0,9823, szltmr (m) = 3,4195e0,0205x ahol x: a fajlagos vegterhels gr veg/furat/ra.

sszessgben megllapthat, hogy 2023 gr veg/furat/ra rtknl kaphatunk 5,5 m-nl alacsonyabb szltmrj ho-mogn termket. Fontos teht az optimlis furatszm megha-trozsa az adott technolgihoz, vegterhelshez.

y = 3,4195e 0,0205x

R 2 = 0,9823

5,0

5,2

5,4

5,6

5,8

6,0

6,2

6,4

18 19 20 21 22 23 24 25 26 27 28 29 30

gr veg/furat/ra

szl

tm

r

3. bra Az vegterhels hatsa a szltmrre Fig. 3. Th e eff ect of the glass load onto the diameter

Spinner hmrskletekBeavatkozs nlkl a szlaztrcsa hmrsklete a palst

mentn flfel cskken. Ennek hatsra a viszkozits merede-ken emelkedik [3]. A magasabb viszkozits folyadk, esetnk-ben az vegolvadk srldsi ellenllsa is nagyobb. A lyuka-kon val tfolyst elidz nyomer a hidrosztatikus nyoms, a folyadkoszlop magassgval a forg mozgsbl ered gyor-sulssal s a srsggel arnyos.

A folyadkoszlop magassga a palst mentn egyre cskken, hiszen az alsbb furatokon eltvozik az veg bizonyos hnyada, gy a nyomer is kisebb lesz (v.. 6. bra). Kt azonos hatst eredmnyez kvetkezmny sszegzdik s a magasabban elhelyezked furatokon egyre kevesebb veg jut t. Az alsbb furatok fajlagos vegterhelse nagyobb, mint a fltte levk, itt magasabb az veg furatbvt koptat hatsa, gy inhomo-gn tmrj szlakat nyernk. Ezeket kikszblend a pa-lst hmrskletprofi ljt egy specilis grendszerrel clszer talaktani gy, hogy a hmrsklet kiss emelkedjen a csk-kens helyett. Esetenknt a gzgket csak levegvel javasolt zemeltetni, ha tl magas a hmrsklet.

Viszkozits hatsa a szltmrre: Az veg viszkozitsa a gyrts, a feldolgozs sorn 1001016 dPas (poise) tartomny-ban van s a hmrsklettel exponencilisan, illetve hiper-bolikusan vltozik. A klnbz folyadkok viszkozits hmrsklet fggsre Vogel [1] a kvetkez sszefggst dol-gozta ki: log = A+B/(T-T0) ahol a viszkozits A B T0 kons-tansok, s T a hmrsklet. Az alkalmazott veg viszkozitst a mrt rtkekbl a [3]-ban ismertetett mdszerrel viszonylag egyszer meghatrozni.

A mindennapi gyakorlatbl ismert, hogy az vegtpus, az vegsszettel vltoztats a szlazhatsg jelents vltozsval, romlsval jr. Az adott veg viszkozitst az 1000 poise hmrskletvel s az veghosszal jellemezhetjk, ez a T: a 104 s 107, 65 poise hmrskletei kztti klnbsg.

Az 1000 poise hmrsklete T^3: A klnbz vegssze-ttelhez tartoz adatokat brzolva a 4. brn bemutatott kap-csolat tallhat a szltmr s az 1000 poise hmrsklete T^3 kzt.

y = 9E -05x 2 - 0,1766x + 89,038R 2 = 0,8851

5,5

6,0

6,5

7,0

7,5

92

5

93

5

94

5

95

5

96

5

97

5

98

5

99

5

10

05

10

15

10

25

10

35

10

45

10

55

10

65

T 10^3 poise

Szl

mik

ron

4. bra A viszkozits hatsa a szltmrre Fig. 4. Eff ect of viscosity for fi ber diameter

Az adatpontokhoz a msodfok polinom illeszthet a leg-jobban. Ezt felhasznlva 950 C-nl van az ltalnos minimum, de a grbn 1015 C-nl is tallunk helyi minimumot.

Az veghossz hatsaA szmolt veghossz T: a 104 s 107,65 poise hmrskletei

kztti klnbsg s szltmr kapcsolatt az 5. bra szem-llteti.

y = 0.0001x 2 - 0.0278x + 7.2666R 2 = 0.8767

5,0

5,5

6,0

6,5

7,0

7,5

0 20 40 60 80 100 120 140 160 180 200 220 240

veghossz T

szl

tm

r

mik

ron

5. bra Az veghossz hatsa a szltmrre Fig. 5. Eff ect of of the glass length onto the fi ber diameter

A mrsi pontokhoz itt is a msodfok polinom illeszthet a legjobban.

A diagram alapjn a 80130 C kztt tallhat a minimlis szltmrhz tartoz optimlis veghossz, T rtke.

Viszkozits hatsa a szlkpzsre

Jellemz Hatsa

T^3 magas vegszl nem nylik, korn dermed vastag szl

T^3 alacsonyvegszl tlzottan nylik, elszakad,

a felleti feszltsg sszetartja az veget vastag szl, veggyngykpzds

T rvid vegszl hamar dermed vastag szl, kristlyosodsi veszly a szlaztrcsban

T hossz vegszl sokig alakthat, elszakadhat veggyngy kpzds

MATERIALS TECHNOLOGY ANYAGTECHNOLGIA


A szlaztrcsa beavatkozs nlkli viselkedse, kialakul tendencik

A szlaztrcsa els kzeltsben hasonl egy alul zrt forg hengerhez, amiben a folyadk, esetnkben az olvadt veg felszne forgsparalelloid alakot vesz fel a kvetkez param-terekkel r a henger sugara, a forg henger szgsebessge, n a fordulatszma, az olvadt veg srsge, z a fggleges, palst irny veg magassga:

z = r22/2g+konstans = 22r2n2/2g+konstans (1)A nyomseloszls pedig:

P =po+ r22/2 - gz = po+ r222n2-gz (2)

r

Z P

6. bra Forg folyadk fellete s nyomsa Fig. 6. Th e surface and pressure of the rotating liquid

A forg mozgs s a szlaztrcsa mreteinek hatsa a k-zelts szerint gy sszegezhet, hogy mindkt paramter, r s n vltoztatsa ngyzetesen hat a z irny folyadkelmozdu-lsra. A forg henger bels felletnek minl nagyobb lefed-shez a henger tmrjt s a fordulatszmot is nvelni kell az (1) sszefggs alapjn. A palstra hat nyoms z = 0 rtknl, azaz a henger aljn a legnagyobb s z emelkedsvel arnyosan cskken, egybknt a henger tmrjvel s a fordulatszmmal is ngyzetesen emelkedik a (2) sszefggs szerint.

Azonos furattmrket felttelezve s fi gyelembe vve azt, hogy a nagyobb nyoms tbb folyadk tfolyst eredm-nyezi a szlaztrcsa furatain, megllapthat, hogy a spin-ner als lyuksorain magasabb az vegterhels, mint a fltte elhelyezkedkn. A nagyobb vegterhels vastagabb vegszlat eredmnyez, teht beavatkozs nlkl mr eleve inhomogn az vegszltmr eloszlsa.

Furatkialaktsok s hatsuk a szlazsraA tnyleges szlkpzst a szlaztrcsa palstjn tbb sor-

ban elhelyezked 8000~40000 furat vgzi. A szlaztrcsa ext-rm feltteleknek kell, hogy megfeleljen. 8001000 C zemi hmrsklet, az olvadt veg korrzit okoz s koptat hatsa, tbb ezres fordulatszm mellett is masszv, stabil legyen a fura-tok mechanikai, statikai gyngtse ellenre. Termszetes, hogy a trcsagyrtk fltett titokknt rzik, s ltalban szabadalom-mal vdik a specilis tvzeteik sszettelt s a lyukkiosztst. A furatok ltalban nem egy oszlopban, hanem klnbz el-tolsokkal helyezkednek el egyms fltt. A szlaztrcsa lta-lnos kialaktsa a 7. brn lthat.

7. bra Szlaztrcsa kialaktsa Fig. 7. Spinner disc

A szlaztrcsa teljestmnyt egyb felttelek mellett alap-veten a furatok szma hatrozza meg. A 3. brnak meg-felelen, gyakorlatomban a 20~23 gr veg/furat/ra furatter-hels eredmnyezett 5,5 m-nl alacsonyabb szltmrt. gy a furatszm nagysgrendi meghatrozsa a kvetkez sszefg-gssel szmolhat:

Furatszm = tervezett kapacits (kg/h)/(20~23 gr veg/furat/h)*1000 (3)

A szlazsi kapacits nvelse tbb furatot ignyel, krds, hogy ezek hogyan helyezhetk el a szlaztrcsa palstjn?

Lehetsges megoldsok:a furattmr cskkentse, a szlaztrcsa tmrjnek nvelse, a szlaztrcsa palst magassgnak emelse, a furatkioszts optimalizlsa, hogy a furatok minl kzelebb kerljenek egymshoz.

A furattmr cskkentsnl s a furatkioszts optimaliz-lsnl fi gyelembe kell venni, hogy az zemid emelkedsvel az olvadt veg furatbvt, koptat hatsa is jelentkezik. Meg-fi gyelseim szerint 500 rs hasznlatnl ez 40~45% tmr nvekedst is okoz. A szlaztrcsa tmrjnek nvelse megkveteli a teljes szlazrendszer, a spinner talaktst, a rgzts, a meghajts, a gz-leveg-ktanyag rendszer jrater-vezst. A szlaztrcsa palst-magassgnak emelse, a szin-tn szksges jratervezsen tl a korbbi hmrsklet profi l jelents megvltozst is okozhatja. Ekkor viszont alaposan fi gyelembe kell venni a hasznlt veg viszkozitsnak drasz-tikus talakulst, lsd [3], mert a magasabb palst nagyobb veghlst eredmnyez s a fels lyuksorra, nem jut el az veg, extrm esetben befagy a spinnerbe, vagy megkezddik a kris-tlyosods.

A furattmr s a fordulatszm egyttes hatsaiAlapveten a kvetkez furattmr kialakts klnbz-

tethet meg:A: a teljes palstmagassgon azonos mret lyukak,B: als lyuksor kisebb, fltte nagyobb furattmr,C: als lyuksor nagyobb, fltte kisebb furattmr.



Gyakorlati tapasztalatok alapjn elmondhat, hogy A s B esetben az zemid emelkedsvel jelentsen bvl a furat, ko-pik a szlaztrcsa s egyre kevesebb veg jut a trcsa tetejn elhelyezked lyuksorokra. Szlssges esetben nem megy fel az veg s a fels lyuksorok nem dolgoznak, az als furatok vegterhelse jelentsen emelkedik. Bevlt gyakorlat, hogy az zemid emelkedsvel A s B esetben arnyosan cskkenteni, mg C esetben nvelni kell a fordulatszmot, s gy cskken az als lyukak vegterhelse s felkszik az veg, az vegterhels egyenletesebb lesz, vkonyabb szl kpzdik.

Kezelszemlyzet A berendezst felgyel, kezelszemlyzet hatsa nem

fogalmazhat meg egzakt sszefggsekkel, de az ISO 9001 minsgbiztostsi rendszernk kialaktsa sorn, a 90-es vekben tapasztaltuk azt, hogy mennyire fontos bevonsuk a rendszer zemeltetsbe. A kezelsi utastsok kidolgozsba aktvan bevontuk ket, s gy rvid, csak a legszksgesebb elvi lerst, annl tbb brt, s az ltaluk is javasolt, rvid, azon-nal alkalmazhat gyakorlati mdszer fogalmaztunk meg. Ezzel cskkentettk a gyakran megnyilvnul szakmai fltkenys-get, a tudom, de nem rulom el felfogst.

A mrt adatok rgztse s feldolgozsaAz optimlis zemeltets, a maximlis termels, a legna-

gyobb szlaztrcsa zemid biztosts, a j minsg vkony szl gyrtsa megkveteli a gyrts paramtereinek folyama-tos dokumentlst s azok elemzst. A klnbz, idnknt felmerl problmk megoldshoz clszer alkalmazni a klnbz statisztikai alapokra pl ksrlettervezsi md-szereket. Jelen tanulmnyom is ezen elvek korbbi szisztema-tikus felhasznlsval jtt ltre.

A szltmr cskkentsnek lehetsgeiAlacsony s magasabb zemidej szlaztrcsk egyidej hasznlata.A furat vegterhels cskkentse. A furattmr cskkentse. Az optimlis viszkozits viszonyok felkutatsa, vegsszettel mdostsa.Az alkalmazott spinner bels ftsnek cskkentse/ nvelse.Az optimlis fordulatszm meghatrozsa s alkal- mazsa.A kezelszemlyzet intuciinak kontrollt engedlye zse. Alkalmazott statisztikai mdszerek hasznlata.

sszefoglalsA dolgozat vzlatosan bemutatja az vegszlgyrtst, rszle-

tesebben foglalkozik a spinner technika nhny sszetevjvel s klcsnhatsaival. Elemzi a viszkozits, a hmrskletek, a szlaztrcsa kialakts, a furattmr, az zemid, az veg-terhels, a fordulatszm elvi s gyakorlati hatsait. Javaslatokat fogalmaz meg az vegszlgyrts optimlsnak lehetsges mdozataira.

Felhasznlt irodalom[1] Vogel, H.: Physikalische Zeitschrift . 22 (1921) 645[2] Hitoshi Kume: Statistical methods for quality improvment AOTS Tokio 1995[3] Szemn Jzsef: A viszkozits szerepe az veggyrtsban ptanyag 58. vf.

2006. 1. szm

Ref.: Szemn Jzsef: Az vegszlgyrts optimalizlsnak lehetsges

mdszerei. ptanyag, 62. vf. 4. szm (2010), 110114. o.

Beszmol a MESSER Hungarogz Kft. budapesti kzpontjban tartott vegipari szakmai konferencirl

LIPTK GYRGY

2010. november 30-n az SZTE veg Szakosztlya sikeres szakmai konferencit tartott a MESSER Hungarogz Kft. budapesti telephelyn mintegy 50 rsztvevvel. Lassan hagyomnny vlik, hogy konferenciinkat vals ipari krnyezetben tartjuk gyrltogatssal egybektve.

Termszetesen rgtn felmerlhet a krds, hogy mirt p-pen a MESSER cg lett az sszejvetelnknek otthont ad vl-lalat, nem pedig pldul egy veggyr. A vlaszt hadd kezdjem egy kis httrmagyarzattal.

Az elmlt kt vtizedben jelents vltozs trtnt az veg-olvaszts technolgijban. Egyre inkbb eltrbe kerlt az oxign felhasznlsa az olvasztsnl. Elszr fleg szak-Amerikban, majd ksbb Eurpban is egyre inkbb trt hdtott az j, gz(olaj)-oxign tzels. Br az j technol-gia nem szortott ki csak egyes specilis esetekben a rgta hasznlt regeneratv/rekuperatv gz(olaj)-levegs tzelst, az

vegipar oxign-felhasznlsa nagysgrenddel megntt. Ma-gyar orszgon tbb helyen trtek t az oxignes tzelsre, fleg a specilis vegek gyrtsnl. A magyar vegipar oxignnel val elltsban a MESSER Hungarogz Kft . vezet szerepet vvott ki magnak, mint megbzhat oxign beszllt. Az veg Szakosztly rdekldse gy fordult az oxigngyrts fel, hogy ne csak a termket ismerjk meg, mint felhasznlk, hanem az elllts folyamatt is. Megkeressnkre a MESSER Hunga-rogz Kft . szvesen vllalkozott arra, hogy otthont adjon a kon-ferencinknak minden kltsgvel egytt

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Építőanyag 2010/04. negyedév