Wyniki wyszukiwania - BazTech

1

Friction processes of selected polymers sliding on steel and duralumin in a lubricant environment

Wieleba W., Leśniewski T., Elemes D., Elemes A.

Tribologia

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2016

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nr 4

201--210

EN

The article presents the results of tribological research into engineering polymers (POM, PEEK, PPS) cooperating in sliding motion with 316L steel and EN AW-2017A aluminium alloy in the presence of a liquid (water, hydraulic oil HLP68). This type of friction pair may occur in hydraulic systems (gear pumps, valves, etc.). For comparison, additionally, the results of tribological research carried out in dry friction conditions have been shown. In addition, the results of microscopic study of the sliding surfaces of polymeric materials have been presented. Analysis of the test results allows one to describe the processes of friction and wear of the studied sliding pairs.

PL

W artykule przedstawiono wyniki badań tribologicznych polimerów konstrukcyjnych (POM, PEEK, PPS) współpracujących ślizgowo ze stalą 316L, a także stopem aluminium EN AW-2017A w obecności cieczy (woda, olej hydrauliczny HLP68). Tego typu pary trące mogą występować w urządzeniach hydraulicznych (pompy zębate, zawory itp.). W celu porównania przedstawiono dodatkowo wyniki badań tribologicznych przeprowadzonych w warunkach tarcia technicznie suchego. Ponadto zaprezentowano wyniki badań mikroskopowych powierzchni ślizgowych materiałów polimerowych. Przeprowadzona analiza wyników badań umożliwiła opisanie procesów tarcia i zużywania badanych par ślizgowych.

2

Wear abrasive resistance of intracorporeal prosthesis of oesophagus

Nowak A. J., Dobrzański L. A.

Journal of Achievements in Materials and Manufacturing Engineering

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2015

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Vol. 69, nr 1

26--32

EN

Purpose: The main aim of the work is investigation of abrasive wear resistance of evaluated oesophageal prosthesis internal layer, considering its long-term exploitation possibility and extreme option of food consumed by patient after implementation. Design/methodology/approach: In the work, methodology of wear abrasive investigations of oesophageal prosthesis, made of long-fibre composite material based on medical silicon, internal surface is presented. The measurements have been done on equipment designed and made in Division of Materials Processing Technology, Management and Computer Techniques in Materials Science of Institute of Engineering Materials and Biomaterials. Findings: The volume of obtained samples mass loss have been determined from approximate calculations of wear trace to simple geometrical figure mapping this loss, ant then the volume of this figure haves been calculated. The CAD software has been used to verify approximation method, which allows to precisely determine mass loss. Research limitations/implications: Developed constructional model of modern, internal prosthesis of the human oesophagus will be used to design the manufacturing technology and to manufacture given prosthesis. Originality/value: Worked out construction is the part of the research project realized by authors, that will result in cognitive, constructional and technological effects, but first of all, it will enable the real help very sick people.

3

Selected properties of plasticized PVC modified by recyclate of polylactide film

Chmielnicki B., Konieczny J., Pakieła W.

Journal of Achievements in Materials and Manufacturing Engineering

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2014

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Vol. 65, nr 1

10--19

EN

Purpose: The main aim of this work is to investigate mechanical properties of plasticized PVC modified by recyclate of polylactide film and influence of aging time in humidity chamber on mechanical properties. Design/methodology/approach: Static test of tensile strength was realized using the testing machine Instron TT-CM 80. Hardness was tested by hardness tester Zwick. Fractures were examined with a scanning electron microscope Zeiss Supra 25. Before the test, the sample was sprayed thin (0.05 mm) silver layer in order to ensure discharge of static electricity from the surface of the sample. PVC granules used is prepared by mixing together at 70°C: PVC 70, plasticizer – dioctyl phthalate FDO Boryszew Erg production and stabilizing lubricant composition. The final materials being studied, obtained by subjecting of the homogenizing extrusion the mixture of granules PVC and recycled PLA. Findings: The analysis of the results gives a real chance to avoid long-term retention of product made from the plastic in the landfill after the end of his exploitation.Research limitations/implications: For the blends of plasticized PVC and recycled PLA derived from films, further structural and tribological resistance examinations are planned. Practical implications: Obtained materials are characterized by satisfactory mechanical properties which make them ideal for use in the packaging industry. The effect of the addition of biodegradable recyclate postconsumer waste in the form of PLA film on plastic susceptibility to degradation under conditions of moisture was confirmed. Originality/value: The article presents selected properties of blends of plasticized PVC and recycled PLA derived from films. The content of recyclate in tested materials varied from 0% to 50%. Introduction to poly (vinyl chloride) degradable additive made it susceptible to degradation in the presence of water, which initiates the biodegradation of polylactide.

4

Evaluation of selected properties of PA6-copper/graphite composite

Konieczny J., Chmielnicki B., Tomiczek A.

Journal of Achievements in Materials and Manufacturing Engineering

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2013

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Vol. 60, nr 1

23--30

EN

Purpose: The aim of this study was to investigate the possibility of improving the tribological properties and thermal conductivity of composites with structural modification of polyamides by the additions of copper and graphite. Design/methodology/approach: The study involved testing polyamide composites containing metallic powder. As the matrix was used polyamide 6 Tarnamid 27 Natural produced by Azoty Tarnów, which strengthened copper, graphite or molybdenum disulfide with varying participation in the composite. Taken tensile test, Brinell hardness, thermal conductivity and the tribological wear resistance. Analyzed the influence of the type of dopant and the participation of the studied property. Findings: The study showed the desirability of the use of graphite and copper as fillers polyamide. The resulting composites are characterized by satisfactory mechanical properties and thermal conductivity. Applied fillers also showed a positive effect on the value of the coefficient of friction wear him down much. Research limitations/implications: No synergistic effect of fillers on the properties of a ternary mixture polyamide-graphite-copper property in all test. Tribological wear for this material was significantly higher than for the binary mixtures of polyamide-graphite and polyamide-copper. According to the literature, composite reinforced with graphite and copper should have a best tribological properties, far in excess of other subjects. Low wear resistance of this material disqualify applications on the nodes friction. Practical implications: The results obtained newly developed composites, combined with the relatively low price of graphite and copper as compared with the price of molybdenum sulfide II may be reasons to use them as analogues of commercial mixtures of PA with MoS2. Originality/value: The results are original and valuable cognitive nature. They bring a new and expanded information about the effects of fillers on mechanical and physical properties. Unique data on tribological wear resistance depends on the type and amount of filler.

5

Rheometric research of polypropylene Licocene PP2602 melts

Mandzyuk I., Romanuke V.

Archives of Materials Science and Engineering

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2011

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Vol. 50, nr 1

31-35

EN

Purpose: To comprehend and ascertain reasons of the transition into the non-Newtonian viscosity zone for the melted polypropylene material, depending upon the number of recycling series. Design/methodology/approach: There were carried researches on rheological features of the primary material of the melted polypropylene Licocene PP2602, subjected to be processed repeatedly in as many series as needed, using the Brookfield viscometer CAP2000+ within the temperature range 130-200şC and the shear rate range 166-3000 s–1. Findings: There were obtained dependence of polypropylene melt viscosity against the shear rate at fixed temperatures, and dependence of polypropylene melt shear stress against the shear rate at fixed temperatures with the non-Newtonian viscosity transient zone shifting into the zone of greater shear rate values as the temperature increases. Also there was obtained dependence of the shear stress critical value on the number of recycling series, where the corresponding critical shear rate value grows as this number increases. This may be applied for predetermining the state of the repeatedly processed polymer material. Research limitations/implications: The found rheometric regularities reflect behaviour for a homologous series of the polymer, but most probably they are generic for all polyolefines, what should be investigated and ascertained subsequently. Practical implications: On the ground of the ascertained temperature-rate dependences of the polypropylene melt flow, there has appeared a possibility to gain a quantitative response about the secondary low-density-polyethylene material state, what allows selecting strategically the way of controlling this material properties, and that let develop new composites of those recycled materials for manufacturing footwear at enterprise “Vzuteks” (Khmelnytskyy). Originality/value: The present paper states that processing the polymer materials repeatedly influences directly on their rheological parameters, increasing, particularly, the melt shear rate critical value.

6

Polymer composite strengthening by developed injection moulding technique

Bilewicz M., Viana J., Dobrzański L.

Archives of Materials Science and Engineering

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2008

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Vol. 30, nr 2

69-72

EN

Purpose: This work presents method of mechanical strengthening of nanoreinforced polymer and immiscible polymer blends of polypropylene (PP) and polycarbonate (PC) obtained by non-conventional injection moulding technique. Design/methodology/approach: Melt manipulation of solidifying polymer inside mould cavity has been used for improving fracture toughness of polymer composites and nanocomposites. Findings: Improvement of mechanical properties, especially for nanocomposites, has been obtained due to different processing conditions and ratios of particular components. Research limitations/implications: Nanocomposites of polymer blends and montmorillonite were moulded by direct injection moulding according to melt temperature and stroke time-number combination included in design of experiments. Practical implications: Comparison of analyzed composites brought satisfying results proving advantage of implicated method and composites ratio as well. Originality/value: Non conventional injection moulding method and their influence on strengthening polymer composites and nanocomposites is promising technology with multi-applicable character.

7

Physical properties of polyazomethine thin films doped with iodine

Hajduk B., Weszka J., Jarząbek B., Jurusik J., Domański M.

Journal of Achievements in Materials and Manufacturing Engineering

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2007

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Vol. 24, nr 2

67-70

EN

Purpose: The aim of this paper is to show influence of doping 1,4-phenylene-methylenenitrilo-1,4- phenylenenitrilomethylene (PPI) with iodine and to propose doping mechanism and its impact on electronic structure of doped PPI thin films. Design/methodology/approach: Influence of iodine doping on electronic structure of polyazomethine thin films was investigated. Optical absorption spectra, XRD spectra and AFM images of doped PPI thin films were recorded. Findings: Doping mechanism relys on removing one electron from PPI pi-system by 12 molecules and forming counterions 13-. Formation of positive polaron means that doping of polyazomethine PPI is p - type. Research limitations/implications: Influence of iodine doping on electrical properties (with increasing of temperature) of PPI thin layers will be checking with Kethley appliance. We plan these measurements to be done in the foreseeable future. Practical implications: Iodine doping of thin PPI films process could results in better electrical conductivity of PPI, so doped polyazomethine films could find some applications for photonic and optoelectronic devices. Originality/value: Conjugated PPI is rarely enough reported but it is very interesting material as it has nitrogen atom in the backbone and it is isoelectronic counterpart of polyparaphenylenevinylene (PPV). This paper show that doping influences on surface morphology, cristallinity and optical properties of polymer. Furthermore, doping mechanism and changes of polymer electronic structure have been proposed in this paper.

8

Influence of electron radiation on surface free energy of low density polyethylene film

Żenkiewicz M.

Journal of Achievements in Materials and Manufacturing Engineering

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2007

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Vol. 25, nr 2

43-46

EN

Purpose: of this paper is to study the effect of the electron radiation, generated in a high voltage accelerator, on surface free energy (SFE) of low density polyethylene film. Design/methodology/approach: An LAE 13/9 linear accelerator (former USSR) was used to irradiate the examined polyethylene film. The maximum electron energy was 13 MeV, controllable energy range, 5-13 MeV, and average power of the electron beam, 9 kW. The contact angles were measured with a G 11 goniometer (Krüss GmbH, Germany) using doubly distilled water, glycerol, formamide, diiodomethane, and alpha bromonaphthalene. The calculations of SFE were done by means of the Owens Wendt or the van Oss-haudhury-Good methods. Findings: The value of the SFE for the polyethylene film, increasing monotonically with the radiation dose, depends on both the applied method of calculation and the set of measuring liquids. The differences between the results obtained with these two methods and sets of liquids generally increase with the radiation dose. Research limitations/implications: The SFE value of polyethylene film depends not only on the intermolecular interactions originating in several outer atomic layers of the film but also on the intermolecular interactions occurring in the measuring liquids and on the way of performing investigations. Thus, it may be compared only when determined with the same method and using the same measuring liquids. Practical implications: The results of presented research allow determining the recommendations referring to the optimization of irradiation technology of low density polyethylene film. Originality/value: The differences in the SFE values calculated with the Owens Wendt and the van Oss Chaudhury-Good methods depend not on only on the kind of the calculation method but also on the kind of measuring liquid used in contact angle measurement.

9

Erosion resistance testing of plastic pipes

Stabik J., Makselon M., Tomanek H.

Journal of Achievements in Materials and Manufacturing Engineering

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2007

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Vol. 25, nr 2

47-50

EN

Purpose: The purpose of this paper was to present the results of a special abrasion test of poly(vinyl chloride) and polypropylene filled with calcium carbonate pipes. Abrasion test's results for pipes were compared with results of standard abrasion test (Taber method) and hardness test. Design/methodology/approach: Short cuts of pipe were subjected to erosion caused by erodent, usually a mixture of special kind of sand and water. The changes of pipe's wall thickness was a measure of resistance to erosion. Additionally abrasion resistance was measured using Taber method and ball-hardness was measured using Brinell apparatus. Findings: Calcium carbonate filled polypropylene exhibited lower resistance to abrasion than hard poly(vinyl chloride). Probably it is the result of filler presence in polypropylene. No correlation between hardness and abrasion resistance was found. Research limitations/implications: Applied method may be used to compare different pipe's materials but its results may not be applied to other plastics products and to other abrasion conditions. Practical implications: Abrasion test used in the research may be applied to compare different materials and different pipelines components. Achieved results showed that calcium carbonate without surface preparation decrease abrasion resistance of polypropylene. Originality/value: Applied method is rarely used for polymer materials testing. Results of presented research may be interesting for pipe manufactures and polymer pipe's formulations producers.

10

Amorphous carbon layers on polymeric substrates

Nowak R. M., Jonas S., Zimowski S., Tkacz-Śmiech K.

Journal of Achievements in Materials and Manufacturing Engineering

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2007

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Vol. 25, nr 1

23-26

EN

Purpose: This paper is aimed to study an effect of nitrogen incorporation on the structure and tribological properties of amorphous a C:N:H layers grown on polycarbonate substrates. Design/methodology/approach: Series of the layers were deposited from CH4 + N2 gas mixture with application of Plasma Enhanced Chemical Vapour Deposition technique assisted by radio waves (RF PE CVD). An analysis of atomic-level structure of the layers was made using FT IR technique. The samples were subjected to investigations of friction coefficient and wear resistance. The respective measurements were performed using Micro-Combi-Tester and a tribometer in ball-on-disc configuration. Findings: The IR spectra of the obtained layers have demonstrated a presence of nitrogen bonded both to carbon and to hydrogen. A formation of the following bonds has been confirmed: -C iden N, -NH2, -C-NH2, >C=NH. All they are typical for a-C:N:H layers. The tribological tests have shown that the layers reduce the friction coefficient of the polycarbonate (up to 50 %) and considerably improve abrasion resistance. Research limitations/implications: Further studies in order to find relations between growing conditions and the properties of the layers should be performed. A role of the chemical composition and structure should be carefully analyzed. Practical implications: An application of carbon overcoats on polycarbonates may improve the usable properties of plastic components (hardness, scratch resistance, UV radiation resistance). This will make polycarbonates attractive materials of wide spectrum of possible applications. Originality/value: It has been shown in this research that application of RF PE CVD technique allows obtaining the a-C:N:H layers improving usable properties of plastics. The layers well adhesive to the substrate may be obtained at the temperatures below 80 degrees centigrade.

11

Prognosing the durability of polymer sealings

Okularczyk W., Kwiatkowski D.

Journal of Achievements in Materials and Manufacturing Engineering

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2006

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Vol. 17, nr 1-2

125--128

EN

Purpose: The paper describes the phenomena connected with the sealing for water hydraulic systems. Design/methodology/approach: For the durability tests two types of sealings, made of three polymeric materials recommended for use in water hydraulics systems have been used. In all investigation arrangements the same guide elements have been used. The tests have been performed maintaining water pressure on the sealing at a level of p = 8±1 MPa and the average speed of the piston rod of v ≈ 0.35 m/sec. Water temperature during investigations was regulated within the range of Tmin = 291 K and Tmax = 305 K. The leakage was distributed to the measurement hoses with the internal diameter of 5mm. For the investigations, the working piston rod with ø 45 f7 with the following parameters has been used: Material: chromium-nickel steel AISI 431 (Cr=16.7%, Ni=2.08%) covered with hard chromium plating of ≥ 20 μm, micro-cracks number ≤ 5 000/mm2, Ra = 0.07 μm. Findings: Weibull method, thanks to its multifunctionality, helps to select elements for certain applications (required long failure-free mileages → high characteristic durability – sealings series 30413). Equipment which works sporadically → low characteristic durability but e.g. lower weight and sizes of sealing element – sealing series 30412. Practical implications: Within the confines of the given research concerning an optimal choice of piston rod sealing for water hydraulic systems, large dependence of the sealing durability on the properly chosen guide elements of the piston rod has been found. In extreme cases the durability changed even a few times. Originality/value: The Weibull method has been applied for assessment of durability and reliability of mechanical parts. A computer program has been used to compare two types of piston rod seals used in water hydraulic power systems. Durability limits have been estimated even though discontinued measurement data were used.

12

Preparation and structure of the electro-deposited Ni-Mo alloys with polymers

Karolus M., Niedbała J., Rówiński E., Łągiewka E., Budniok A.

Journal of Achievements in Materials and Manufacturing Engineering

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2006

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Vol. 16, nr 1-2

25--29

EN

Purpose: The aim of the paper is presentation the process of forming the Ni-Mo electrodeposited layers with polypyrrole, polytiophne and polyethylene. Design/methodology/approach: There are three ways of polymeriztion and layer depositon. Findings: In case of polytiophen + Ni-Mo – there is observed process of electropolymerization and Ni-Mo electrodeposition in the cathodic process. In case of polypyrrole + Ni-Mo – there is observed two-step process: electropolymerization in the anodic process and Ni-Mo electrodeposition in the cathodic process. So the composite is forming when the electrodes have worked alternately as the anode and as the cathode. In case of polyethylene + Ni-Mo – there is observed process of Ni-Mo electrodeposition with grains of polyethylene in the cathodic process. From structural analyses by X-ray diffraction it was noticed that the solid solution of Mo in Ni is forming. The unit cell parameters of solid solution are slightly changing with the incerasing of molybdenum contents in the alloy from the value 3.57 to 3.61 Å. In case of all polymers, the crystallite size calculated basing on the Williamson-Hall theory is about 5-6 nanometers. Practical implications: The codeposition of alloys with polymers or polymerisation with alloys codeposition has created new opportunities in the preparation of novel composite materials. Conductive polymers have been investigated for use as the electrode materials for a number of applications including rechargeable batteries, electrochemical sensors etc. Electrochemical method described in this paper is unique in that it can be used for processing ceramics, polymers, metals, composites and hybrid materials. Originality/value: Using the electopolymerization and electrodeposition processes in preparation of the composites.

13

Modification of PVC compounds with butadiene-acrylonitrile elastomers

Rojek M., Stabik J.

Journal of Achievements in Materials and Manufacturing Engineering

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2006

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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.

14

Influence of variability of polymer processing on the manufacturing system

Koszkul J., Pietrzak M., Gzieło A., Postawa P.

Journal of Achievements in Materials and Manufacturing Engineering

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2006

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Vol. 17, nr 1-2

253--256

EN

Purpose: The aim of the paper is to present the influence of variability of polymer materials processing parameters on the production process. To determine this influence, the queuing theory and system dynamics method have been applied. Design/methodology/approach: The measurements and control of the time of operation can be performed by means of the traditional methods of statistical control. Full dynamics of the variability phenomenon can be reflected by means of computer simulation. Findings: The measurements of parameters on the basis of real manufacturing system have been performed. The dependences between the parameters have been determined and several computer simulations have been performed. On the basis of the obtained results the influence of the individual production parameters on the manufacturing system has been determined. Research limitations/implications: The performed analysis enabled to assume that the highest influence on the manufacturing process and especially on the time of material flow has the time of injection of the polymeric materials. Reductions in utilization tend to have a much larger impact on delay then reduction in variability. However, because capacity is costly, high utilization is usually desirable. Originality/value: The investigation results can be the basis to develop efficient methods for reduction of variability and hence the methods of production costs reduction. Variability reduction is often the key to achieving high efficiency logistical and manufacturing system.