Wyniki wyszukiwania - Biblioteka Nauki

1

The influence of X-rays on strength properties of polyester vascular system prosthesis

100%

Rojek M. , Stabik J.

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2009

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tom Vol. 35, nr 1

47-54

EN

Purpose: of this paper was to evaluate the influence of X-ray irradiation on mechanical properties of polyester yarn used in production of vascular system prosthesis. Patients with such prosthesis are subjected to multiple X-ray radioscopic exposures. This can negatively influence prosthesis strength and durability. Design/methodology/approach: Polyester yarn tensile strength properties were measured before sterilisation and X-ray irradiation. Next a part of yarn was subjected to irradiation sterilisation. Sterilised and non-sterilised yarn was next exposed to multiple X-ray irradiation and to continuous irradiation. After each irradiation dose tensile strength and elongation at break were measured. Findings: The influence of X-ray irradiation dose on mechanical properties was evaluated. It was established that dose equivalent to multiple X-ray radioscopic exposures did not substantially influenced strength properties of polyester yarn. Research limitations/implications: To fully evaluate the influence of X-ray irradiation on prosthesis strength and durability working in human body environment it is planned to continue described research. Simultaneous influence of X-ray irradiation and body fluids on mechanical properties of polyester yarn will be tested. Practical implications: Research results proved that patients with polyester vascular prosthesis may be subjected to X-ray radioscopy without any anxiety concerning prosthesis strength properties or durability. Originality/value: The main research value is its basic conclusion that multiple X-ray irradiation does not significantly influence strength and flexibility of polyester yarn applied to vascular system prosthesis manufacture.

2

Modification of PVC compounds with butadiene-acrylonitrile elastomers

100%

Rojek M. , Stabik J.

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tom Vol. 17, nr 1-2

141--144

EN

Purpose: The purpose of the paper is to present the research programme on influence of acrylonitrile-butadiene copolymers on properties of plasticized polyvinylchloride as window gaskets material. Design/methodology/approach: Short literature review concerning application of modified PVC as gasket material was presented. In experimental part two types of acrylonitrile-butadiene copolymers were used as elastomeric plasticizers. Compounds with fifteen different levels of modifiers content (up to 25% by weight) were prepared and tested. Additionally three commercial compounds were tested as reference formulations. The following test were performed: Shore hardness, short-term and long-term elastic recovery, tensile strength, elongation at break and migration of plasticizers from gasket material to unplasticized PVC. Findings: Application of acrylonitrile-butadiene copolymers as PVC modifier enhanced many properties essential for window gasket materials such as long-term and short term elastic recovery, tensile strength and elongation at break. At the same time addition of these elastomers did not change migration of other plasticizers contained in gasket material. Obtained results indicated that among tested compounds best properties as gasket material exhibited plasticized PVC with 23% of acrylonitrile-butadiene copolymer Chemigum P83. Reference commercial compounds exhibited worse performance properties than compounds with this acrylonitrile-butadiene copolymer. Practical implications: Research programme allowed to elaborate plasticized PVC compounds modified with acrylonitrile-butadiene copolymer that can be industrially applied for PVC window gaskets. Originality/value: Obtained results are of scientific and practical value. Research programme allowed to investigate the influence of elastomeric modifiers on plasticized PVC properties. Research results are also of practical importance.

3

Influence of low melting point alloy on strength properties of epoxy resin

100%

Stabik J. , Wierzbicki Ł.

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tom Vol. 60, nr 1

13--23

EN

Purpose: The aim of the work was to determine the effectiveness of the modification of the epoxy resin strength and elasticity by Wood’s alloy particles addition. Design/methodology/approach: Manufacture method of thermosetting polymer matrix composite materials reinforced with the Wood’s alloy particles was searched. First of all mixing conditions were differentiated to obtained good dispersion of reinforcement in polymeric matrix. Microscopic examination of samples cross-sections was performed in order to search the structure of prepared composite materials. The strength and elasticity of composites were investigated using compression test. Findings: The results of the compression tests and their analysis are presented. The paper also presents microscopic images of structure of prepared composites. Research limitations/implications: Presented research was limited to composites in the form of small samples. The developed technology of this type of composites preparation is limited to small volumes because of sedimentation process action. Practical implications: Materials with low melting point alloy content show many possible applications. First of all they are materials with higher thermal conductivity and electrical conductivity than standard polymeric materials. Conducted research programme showed that these materials exhibit also good mechanical properties. Originality/value: Preparation method of thermosetting polymer matrix composite materials reinforced with the Wood’s alloy particles fabricating method was developed. Composites with good mechanical properties were obtained. Microscopic examination of samples cross-sections in order to search the structure of prepared composite materials was performed. Composites with small particles evenly dispersed in epoxy matrix were achieved.

4

Nowa metoda wytwarzania precyzyjnych podstaw pod prowadnice liniowe z wykorzystaniem kompozytów o osnowie epoksydowej

100%

Stabik J. , Florek G.

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tom [R.] 19, nr 6 (156)

647--652

PL

Artykuł zawiera opis proponowanej przez autorów, nowatorskiej technologii wytwarzania podstaw pod prowadnice liniowe maszyn i urządzeń, wykorzystującej kompozyt polimerowy o osnowie epoksydowej. Celem opracowania nowej metody było znaczące obniżenie kosztów wykonania ram maszyn i urządzeń wyposażonych w prowadnice liniowe oraz umożliwienie wytwarzania powierzchni pod prowadnice w miejscu ich montażu. W pracy omówiono koncepcję technologii oraz materiały i metody użyte przy budowie konstrukcji doświadczalnej.

EN

The article includes a description of, as proposed by the authors, the innovative method of producing bases for linear guides of machinery and equipment using a polymer composite material with epoxy matrix. The aim of the new method was to provide a significant reduction in manufacturing costs of machines and device frames, equipped with linear guides and to enable manufacturing of bases for linear guides at the production site. The paper discusses the concept of technology, materials and methods used in the construction of the experimental design.

5

Mechanical and electrical properties of mined coal filled polyethylene and polyamide

100%

Rojek M. , Stabik J.

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2009

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tom Vol. 36, nr 1

34-40

EN

Purpose: The purpose of the present paper is to present results of basic mechanical properties research of high-density polyethylene and polyamide 6 filled with two kinds of mined coal particles. Because composites with carbon are expected to poses low electric resistance also surface resistivity was measured. Design/methodology/approach: Dependences of tensile strength, elongation at break, impact strength, ball hardness and surface resistivity on volume content of mined coal in polymeric matrix are measured and discussed. Findings: Introduction of mined coal fine particles to polyethylene did not cause significant changes in tensile strength, while the same property of polyamide composites decreased significantly. Brinell ball hardness of all polyethylene and polyamide composites increased almost proportionally to coal content. Pronounced lowering of deformability (elongation at break) with increasing coal content was observed for all formulations. Also impact strength significantly decreased after mined coal filling. Significant lowering of surface resistivity was noticed especially for coal-polyamide composites. Research limitations/implications: Obtained results showed that mined coal fine particles can be applied as a filler of thermoplastic polymers but poor adhesion between polymer matrix and filler particles was achieved. Additional research on mined coal fine particles modification by coupling agents is needed to develop better adhesion. Practical implications: Obtained results showed that mined coal fine particles can be applied as a filler of thermoplastic polymers but poor adhesion between polymer matrix and filler particles was achieved. Additional research on mined coal fine particles modification by coupling agents is needed to develop better adhesion. Originality/value: Polymer composites with carbon as a modifier has been used for many years but there have been only a few experiments on introducing fine particles of mined coal into thermoplastics.

6

Ilościowa ocena zawartości proszku węgla w kompozytach o osnowie polimerowej metodą termografii aktywnej

80%

Stabik J. , Pawlak S. , Chomiak M. , Muzia G.

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tom [R.] 18, nr 4

361-364

PL

W artykule przedstawiono zastosowanie termografii aktywnej do ilościowej oceny zawartości proszku węgla (grafitu i węgla antracytowego) w kompozytach o osnowie epoksydowej. Uzyskane podczas badań termograficznych charakterystyki czasowo-temperaturowe użyto do wyznaczenia dyfuzyjności cieplnej kompozytów. Na podstawie uzyskanych wyników badań stwierdzono, że zaproponowana metoda badawcza może być z powodzeniem zastosowana do ilościowej oceny zawartości proszku węgla w kompozytach polimerowych o osnowie epoksydowej.

EN

The application of active thermography for the quantitative assessment of carbon powder (graphite and anthracite coal) content in epoxy matrix has been presented in this article. Temperature-time dependences obtained during thermographic measurements were used to determine the thermal diffusivity of composites. On the basis of obtained results of the measurements, it was summarized that the proposed testing method can be applied in quantitative assessment of carbon powder content in epoxy matrix composites.

7

Metodyka przygotowania próbek polimerowego materiału gradientowego do badań mikroskopowych

80%

Stabik J. , Chomiak M. , Suchoń Ł.

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tom [R.] 18, nr 4

356-360

PL

W artykule omówiono zagadnienia przygotowania powierzchni próbek polimerowego materiału gradientowego do badań mikroskopowych. Próbki wykorzystane do badań wykonane były z żywicy epoksydowej jako materiału osnowy oraz proszku węgla kamiennego jako napełniacza. Kompozyty wytworzono stosując metodę odlewania odśrodkowego. Na podstawie analizy zdjęć mikroskopowych wybrano metodę pozwalającą na obserwacje próbek na mikroskopie świetlnym. Badania wykazały, że procedura szlifowania papierem ściernym a następnie polerowania na mokro, bez użycia materiału ściernego, pozwala na uzyskanie zdjęć mikroskopowych o najlepszej jakości z dobrze widocznymi ziarnami napełniacza.

EN

The article discusses the issues of surface preparation of polymeric gradient material for microscopic examination. Specimens used for research were made of epoxy resin as a matrix and coal powder as a filler. The composites were prepared using centrifugal casting method. The selected method allows the observation of the specimens using light microscopy on the basis of the analysis of microscopic images. Research has shown that the procedure of grinding with abrasive paper and then wet polishing, without the use of abrasive, allows to obtain microscopic images of best quality with clearly visible filler grains.

8

Numerical models of polymeric composite to simulate fatigue and ageing processes

80%

Wróbel G. , Kaczmarczyk J. , Stabik J. , Rojek M.

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tom Vol. 34, nr 1

31-38

EN

Purpose: of this paper was to prove the possibility of applying numeric model of polymer composite, consisting of finite elements, to simulate dynamic acoustic and thermal processes. Characteristics of these processes evaluated numerically, in comparison with experimental results, could allow to simulate complex structural processes taking place during fatigue and ageing degradation of composite. It is expected to prove relations between chosen physical properties of simulated processes and strength characteristics determining load capacity of materials. Design/methodology/approach: Planar, biphase model of fibre reinforced laminate was applied. Pseudo-random procedure of model structure and physical parameters modification was used. A programme of numerical simulations was performed to evaluate sensitivity of characteristics of acoustic wave propagation and heat transport processes on model modifications. Findings: Possibility of model structural and parametric modifications resulting in changes of composite physical properties, such as stiffness, acoustic wave propagation velocity and thermal conductivity, observed during degradation processes was demonstrated. Research limitations/implications: It is expected that results of composite testing programme, being now realized by authors, will allow quantitative adjustment of acoustic and thermal characteristics achieved numerically and experimentally. Practical implications: Complete identification of numerical model characteristics and procedure of its modification is expected to allow to estimate the degree of strength properties degradation on the basis of numerical simulations results. Originality/value: Proposed numerical models for simulation of composite degradation due to fatigue and ageing processes are new and original tools supporting non-destructive evaluation of strength properties changes.

9

Investigation of processing properties of polyamide filled with hard coal

80%

Stabik J. , Suchoń Ł. , Rojek M. , Szczepanik M.

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tom Vol. 33, nr 2

142-149

EN

Purpose: The aim of this article is to present the influence of contents and kind of hard coal used as powder filler on rheological properties (viscosity) of polyamide 6. Design/methodology/approach: Preparation of composite of polyamide 6 with hard coal was carried out on laboratory twin screw extruder. Extruded composite was granulated and in this form was used for MFR analysis. Taking into account MFR results viscosity was calculated. The influence of filler content on viscosity was next searched. Findings: Results of research showed that addition of powdered hard coal to polyamide 6 matrix cause pronounced decrease of MFR index. In this way significant increase of viscous flow was observed. It is often observed phenomenon for polymer composite filled with powder materials. Research limitations/implications: It is necessary to carry out the research with surface modified hard coal with coupling agents which provide better adhesion of polymer matrix to filler. Practical implications: Hard coal used as a filler in composites makes it possible to gain new and cheaper polymeric materials with many possible applications. Originality/value: Investigation described in article shows possibility of hard coal application as innovatory filler of polymers. The influence of this filler on rheological properties indicate that processing of these new materials may be accompanied with some problems.

10

Carbon materials as fillers for polymer matrix composites

80%

Stabik J. , Rojek M. , Suchoń Ł. , Mrowiec K.

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tom Vol. 53, nr 1

29-37

EN

Purpose: Paper presents different types of carbon materials used as modifiers for polymer matrix composites. The article contains summary description of the available varieties of carbon materials from brown and hard coal to the carbon nanotubes and fullerenes. Design/methodology/approach: The aim of the publication is to present different forms of carbon materials, their origins and ways of creation. Paper summarizes also basic properties and possible applications of carbon materials as components of engineering polymeric composites. Findings: Paper especially focuses on types of hard coal (mine coal) as potential fillers for polymers. These materials and their properties and applications were studied in detail by the authors in previous researches. Research limitations/implications: Analysis of the literature and authors’ own research results indicate that carbon materials as fillers can essentially improve many different properties of polymer matrix composites but still have to be extensively searched to fully evaluate their characteristics and possible applications. Practical implications: Particular attention should be directed to the use of mined coal as a properties modifier of polymers because of its interesting properties, low prize and availability in Poland. Originality/value: New types of carbon materials as polymer fillers, their properties and application possibilities are presented.

11

Wpływ filtracji uplastycznionego recyklatu PET na własności mechaniczne folii trójwarstwowej

80%

Stabik J. , Szymiczek M. , Wróbel G. , Rojek M.

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tom T. 22, Nr 5 (173)

494--499

PL

W artykule przedstawiono wyniki badań mechanicznych trójwarstwowej folii wytłoczonej z poli(tereftalanu etylenu) - PET. Warstwa wewnętrzna folii wykonana była z recyklatu PET poddanego filtracji na zestawach sit o różnej wielkości oczek. Na wstępie omówiono proces filtracji uplastycznionych materiałów polimerowych. W ramach badań określono wpływ gęstości sit filtracyjnych na podstawowe własności mechaniczne określone w próbie rozciągania. Wyniki badań wskazują, że własności recyklatu poddanego filtracji są zbliżone do własności oryginalnego, handlowego tworzywa. Wraz ze wzrostem wielkości oczek zaobserwowano niewielkie obniżenie własności wytrzymałościowych i zwiększenie rozrzutu wyników.

EN

The paper presents results of mechanical tests of extruded three-layer poly(ethylene terephthalate) - PET film. The inner layer of the film was produced of PET recyclate subjected to filtration using sieves with different mesh size. At the beginning filtration process of polymer melts is shortly presented. Within the framework of research the influence of mesh size of filtration screens on basic mechanical properties determined in tensile strength test was determined. Achieved results indicate that properties of recyclates subjected to filtration are similar to properties of virgin material. A slight decrease in strength properties and greater scatter of results with the mesh size increase was observed.

12

Research on polyamide matrix composites filled with hard coal

71%

Rojek M. , Stabik J. , Szymiczek M. , Suchoń Ł. , Mrowiec K.

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tom Vol. 57, nr 1

13-20

EN

Purpose: The aim of this paper is to present the summary results of studies on polyamide composites filled with hard coal. Research on the use of coal as a filler of polymers are conducted for many years in Division of Metallic and Polymeric Materials Processing, Silesian University of Technology. This paper summarizes results obtained in different research programmes preformed in recent years. Described materials are polyamide 6 composites filled with modified and unmodified hard coal powder. Design/methodology/approach: All the resulting compositions intended for research have been produced using twin screw extruder. The resulting mixtures of various compositions were then subjected to a process of granulation. The prepared composites have undergone a process of injection moulding which allowed to obtain samples for strength tests. Full statement of research results obtained for composites could help to predict the material with the best mechanical properties and hence the best material for construction. Findings: It has appeared from studies that in both a composite made of unmodified coal and of coal modified with coupling agents show a decrease in mechanical properties in comparison with the neat polymer. Apart from this these composites are interesting materials because of low prize of the filler. Research limitations/implications: It can be concluded from research that all types of obtained composites are characterized by a decrease in mechanical properties. Practical implications: Applications of hard coal as a filler of polymer composites is way to produce new materials. It is worth noting that the main features of the filler used is its prevalence, low cost and electrical conductance. Originality/value: The results describe new fillers of thermoplastic polymers and the possibility of its modification.

13

Composite materials with the polymeric matrix applied to ballistic shields

61%

Rojek M. , Szymiczek M. , Stabik J. , Mężyk A. , Jamroziak K. , Krzystała E. , Kurowski J.

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tom Vol. 63, nr 1

26--35

EN

Purpose: The purpose of the series of research is drawing up an alternative armour plate with the composite structure, which would be resistant to 7.62 and 5.56 caliber bullets fired from the weapons the Polish army is equipped with. Design/methodology/approach: The research embraced the composite materials with epoxy matrix reinforced with the fiberglass in the shape of mat or fabric, and steel mesh. Three sheets of epoxy-glass composite were made on which ceramic panels were glued. Findings: The result of the presented work is the assessment of the quality of examined samples. As a criterion was adopted the behaviour of the material under the shellfire, its defragmentation, puncture and destruction. Research limitations/implications: The research was limited to composite materials with the epoxy matrix and reinforcement of fiberglass in the form of mat or fabric. In the next stage of the research the application of aramid fibers reinforcement is planned. Practical implications: Practical implications Worked out the construction material systems make the basis for further analysis and optimization of materials applied as the alternative for heavy army vehicles. Such application enables the minimization of the weight of a vehicle. Originality/value: Paper presents innovative composites polymer materials applied for ballistic protection of lightweight armed vehicles.