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Tytuł:
Methodology for experimental investigations of metal foams and their mechanical properties
Metodologia badań eksperymentalnych pian metalicznych i ich własności mechanicznych
Autorzy:
Stręk, A. M.
Powiązania:
https://bibliotekanauki.pl/articles/368916.pdf
Data publikacji:
2012
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Wydawnictwo AGH
Tematy:
pianki metaliczne
próba rozciągania pianek
próba ściskania pianek
próba wieloosiowa pianek
test ścinania pianek
metal foams
tensile tests of foams
compression tests of foams
multiaxial tests of foams
shear tests of foams
Opis:
This paper presents a comprehensive, systematic approach on experimental investigations of structure and mechanical properties of metal foams. Based on a thorough state of the art study, the existing solutions have been synthesised with recent developments in the discussed field to become a proposition of a possibly complete methodology for observation and testing of cellular metals. Material properties acquired in the described manners can constitute reliable reference result base e.g. for identification and verification of failure criteria. This paper describes sample preparation procedures and next discusses techniques which enable one to characterise foam structure. There are also presented procedures for determining strength limits in different load cases: uniaxial tension or compression, shear and torsion as well as multiaxial states. The tests are discussed in terms of their specific application to study cellular metallic materials.
Przedstawiono kompleksowe, systematyczne podejście do badań doświadczalnych struktury i właściwości mechanicznych pian metalowych. Na podstawie dogłębnej analizy stanu rzeczy rozwiązania istniejące zsyntetyzowano, uwzględniając najnowsze zmiany w omawianym zakresie tak, aby przedstawić propozycje możliwie pełnej metodologii obserwacji i badań metali komórkowych. Właściwości materiału uzyskane w czasie zaproponowanych testów mogą stanowić wiarygodną bazę odnośnych wyników, np. do identyfikacji i weryfikacji kryteriów wytężenia. Opisano procedury przygotowania próbek, a następnie omówiono techniki umożliwiające scharakteryzowanie struktury piany. Przedstawiono również procedury określania granic wytrzymałości w różnych przypadkach obciążenia: jednoosiowego rozciągania lub ściskania, ścinania i skręcania oraz wieloosiowych stanach obciążenia. Badania zostały omówione w odniesieniu do szczególnego zastosowania ich do zbadania komórkowych materiałów metalicznych.
Źródło:
Mechanics and Control; 2012, 31, 2; 90-96
2083-6759
2300-7079
Pojawia się w:
Mechanics and Control
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Evaluation of the Cause and Consequences of Defects in Cast Metal-Ceramic Composite Foams
Autorzy:
Popielarski, P.
Sika, R.
Czarnecka-Komorowska, D.
Szymański, P.
Rogalewicz, M.
Gawdzińska, K.
Powiązania:
https://bibliotekanauki.pl/articles/2079776.pdf
Data publikacji:
2021
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
foams
composites
casting
defects
Opis:
In this research, the quality of manufactured cast metal-ceramic foams (manufactured using blowing gas) was tested. The causes responsible for defect formation in the composite foams and their consequences were analyzed using the FMEA (Failure Mode and Effects Analysis) method, which is a useful tool for minimizing losses caused by low product quality. This method involves analytically determining correlations between the cause and consequences of potential product defects, and it takes into account the criticality factor (risk). The FMEA analysis showed that pore breaks were the most "critical defect" (with the highest number of effects on the product, the Risk Priority Number, affecting the quality of the composite foam). The second most critical defect was discontinuities in the foam frame structure. Destruction or damage to the foam structure (although very rare) deprived the composite foam of its primary function, which is to reinforce the product. The third most critical defect was non-uniform foam pore size.
Źródło:
Archives of Foundry Engineering; 2021, 21, 1; 81-88
1897-3310
2299-2944
Pojawia się w:
Archives of Foundry Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Application of the filtration bed with a foamsand filling for treatment of sewage with an elevated concentration of ammonia nitrogen
Autorzy:
Dacewicz, Ewa
Powiązania:
https://bibliotekanauki.pl/articles/101424.pdf
Data publikacji:
2019
Wydawca:
Polska Akademia Nauk. Stowarzyszenie Infrastruktura i Ekologia Terenów Wiejskich PAN
Tematy:
filtration bed
polyurethane foams
sewage
treatment
Opis:
The two-stage technological system for the treatment of domestic sewage, characterized by an elevated concentration of ammonium nitrogen, consisted of a settling tank and a vertical flow multi-layer filter bed with a sponge-sand filling was analyzed. In the upper part of the filling in the form of spongy polyurethane foams there was the removal of hardly decomposable organic compounds and ammonium nitrogen without the need for additional aeration. In the lower layer of quartz sand, the removal of orthophosphates and pathogenic bacteria took place. After 400 days of operation, multi-layered filter beds achieved high average removal efficiency under variable hydraulic load conditions. The upper 30 cm layer of waste foams used, combined with the 60-cm bottom layer of sand, proved to be very effective in the removal of ammonium nitrogen and organic compounds. The degree of N-NH4 + , CODCr and BOD5 elimination was at 91.6, 77.4 and 91.7% respectively. The 30-cm upper layer of waste foams used combined with the 60-cm lower layer of sand allowed for removal of Escherichia coli in 98.9% on average, whereas coliform bacteria - in 95.0%.
Źródło:
Infrastruktura i Ekologia Terenów Wiejskich; 2019, III/1; 165-180
1732-5587
Pojawia się w:
Infrastruktura i Ekologia Terenów Wiejskich
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Preparation and Evaluation of Properties of Cast Metallic Foams with Regular Inner Structure
Autorzy:
Lichý, P.
Elbel, T.
Kroupová, I.
Radkovský, F.
Powiązania:
https://bibliotekanauki.pl/articles/353931.pdf
Data publikacji:
2017
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
metallic foams
casting
microstructure
mechanical properties
Opis:
Lately we encounter still more new applications of metallic foams, as well as possible methods of their manufacture. These metallic materials have specific properties, such as large rigidity at low density, in some cases high thermal conductivity, capability to absorb energy, etc. The work is focused on the preparation of these materials using conventional casting technology, which ensures rapid and economically feasible method for production of shaped components. In the experimental part we studied conditions of casting of metallic foams with a regular structure made of ferrous and non-ferrous alloys. For thus obtained castings we evaluated the achieved microstructure and mechanical properties, which determine the possible use of these materials. The samples were subjected to compression tests, by which we investigated deformation behaviour of selected materials and determined the value of energy absorption.
Źródło:
Archives of Metallurgy and Materials; 2017, 62, 3; 1643-1646
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
New amine adducts with carbon dioxide as blowing agents in the production of integral polyurethane foams
Nowe addukty amin z ditlenkiem węgla jako porofory w produkcji integralnych pianek poliuretanowych
Autorzy:
Szczepkowski, Leonard
Ryszkowska, Joanna
Auguścik-Królikowska, Monika
Leszczyńska, Milena
Przekurat, Sylwia
Przekurat, Adam
Powiązania:
https://bibliotekanauki.pl/articles/947332.pdf
Data publikacji:
2020
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Chemii Przemysłowej
Tematy:
blowing agents
carbon dioxide adducts
integral foams
polyurethane foams
porofory
addukty ditlenku węgla
pianki integralne
pianki poliuretanowe
Opis:
Blowing agents play an important role in the production of cellular polyurethanes. The traditional chemical blowing agent H2O/CO2 did not meet all application requirements. This led to the introduction of physical foaming agents in the 1950–1960s, which were subject to four further modifications due to climatic hazards. The recently introduced new generation of hydrofluoroolefins (HFOs) hydrocarbons is currently in the application assessment and meets the utility and climate requirements for now. Without waiting for a long-term final assessment of this blowing agent group, an attempt was made to introduce carbon dioxide in the form of adducts with aliphatic amines into the foaming process. As example compounds, CO2 adducts with aliphatic hydrocarbons containing also primary, secondary and tertiary nitrogen atoms in the same molecule were used. The synthesis of adducts was carried out by the absorption of carbon dioxide gas in a solution of amines in monoethylene glycol (MEG) and triethanolamine (TELA). The resulting solutions containing 12–16 wt % CO2 were next used in the application-oriented study. Amines regulating the foaming and gelation processes were used for the production of adducts, which allowed the elimination of organometallic gelling additives. Selected adducts were checked during the production of furniture chair seats on an industrial scale, obtaining integral foams in the range of density 190–294 kg/m3 and hardness 22–38 °ShA. In the production process of these foams carried out at PLASTPUR a double-stream foaming machine from Hennecke was used.
Środki porotwórcze odgrywają istotną rolę w produkcji poliuretanów (PUR) komórkowych. Tradycyjny chemiczny środek porotwórczy, jakim jest H2O/CO2, nie spełnia wszystkich wymagań aplikacyjnych, co doprowadziło w latach 1950–1960 do wprowadzania na rynek fizycznych środków spieniających – hydrofluoroolefin (HFO). Jednak ze względu na zagrożenia klimatyczne wynikające z ich stosowania poddawano je kolejnym czterem modyfikacjom. Ostatnio opracowana, nowa IV generacja węglowodorów typu HFO spełnia wymagania użytkowe i klimatyczne i obecnie jest na etapie oceny aplikacyjnej. Nie czekając na ocenę końcową tej grupy poroforów, podjęto próbę wykorzystania do procesu spieniania PUR ditlenku węgla w postaci adduktów z aminami alifatycznymi. Jako związki przykładowe użyto addukty CO2 z węglowodorami alifatycznymi zawierającymi w tej samej cząsteczce także atomy azotu I-rzędowe, II-rzędowe oraz III-rzędowe. Syntezę adduktów prowadzono metodą absorpcji gazowego ditlenku węgla w roztworze amin w glikolu monoetylenowym (MEG) i trójetanoloaminy (TELA). Otrzymane roztwory zawierające 12–16% mas. CO2 stosowano w dalszych badaniach aplikacyjnych. Do wytwarzania adduktów użyto aminy regulujące procesy spieniania i żelowania, co pozwoliło na eliminację metaloorganicznych dodatków żelowania. Wytypowane addukty zastosowano w produkcji w skali przemysłowej siedzisk do krzeseł meblarskich, wytworzonych z pianek integralnych o gęstości z zakresu 190–294 kg/m3 oraz twardości 22–38 °ShA. W procesie otrzymywania tych pianek, przeprowadzonym w firmie PLASTPUR, wykorzystano dwustrumieniową maszynę spieniającą firmy Hennecke.
Źródło:
Polimery; 2020, 65, 10; 681-690
0032-2725
Pojawia się w:
Polimery
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Multifunctional oligoetherols and polyurethane foams with carbazole ring
Autorzy:
Lubczak, R.
Powiązania:
https://bibliotekanauki.pl/articles/778805.pdf
Data publikacji:
2016
Wydawca:
Zachodniopomorski Uniwersytet Technologiczny w Szczecinie. Wydawnictwo Uczelniane ZUT w Szczecinie
Tematy:
carbazole
sorbitol
hydroxyalkylation
oligoetherols
thermal stability of foams
Opis:
A new method of preparation of multifunctional oligoetherols containing carbazole ring is presented. The oligoetherols were obtained in the reaction of 9-(2,3-epoxypropyl)carbazole with sorbitol and oxiranes like ethylene and propylene oxide. The structure of obtained oligoetherols was determined by IR, H-NMR and MALDI-ToF spectroscopies. Physical properties of the products render them good candidates for preparing polyurethane foams. The foams were obtained and their properties were examined. It has been found that the foams are rigid at room temperature and their apparent density was 50–70 kg/m3. The water uptake was low, maximum to 6.5 mass%. Obtained foams have high thermal resistance. Dynamic thermal analysis of these foams showed that 5% mass loss was initiated at 250–300oC, while temperature of 50% mass loss was 370–404oC. Concomitantly the increase of compression strength was observed.
Źródło:
Polish Journal of Chemical Technology; 2016, 18, 1; 120-126
1509-8117
1899-4741
Pojawia się w:
Polish Journal of Chemical Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Mechanical characterization of orthotropic elastic parameters of a foam by the mixed experimental-numerical analysis
Autorzy:
Chuda-Kowalska, M.
Gajewski, T.
Garbowski, T.
Powiązania:
https://bibliotekanauki.pl/articles/279786.pdf
Data publikacji:
2015
Wydawca:
Polskie Towarzystwo Mechaniki Teoretycznej i Stosowanej
Tematy:
orthotropic elastic foams
digital image correlation
inverse analysis
Opis:
Different kind of foams, usually made from polymers, metals, ceramics, glass, etc. have been widely used in various branches of civil engineering since the 80s. The most common are polyurethane foams. Since their role in construction nowadays is not only to act as a thermal barrier but also to take some of loads, the engineers need to know also their mechanical properties. This implies that manufacturers or designers must perform a number of laboratory tests in order to find a set of substantial parameters of this particular material. Due to noticeable orthotropic behavior of foams, one needs to carry out several laboratory tests to identify elastic properties only. Here, an enhanced testing methodology is proposed to reduce the number of tests required for characterization of elastic orthotropic properties of foams. By combining the advanced measurement techniques, non-traditional experimental setup, numerical modeling and inverse analysis one can capture all nine elastic properties from just two or three tests. In the paper, full experimental and numerical procedures are presented and validated by noisy pseudo-experimental data.
Źródło:
Journal of Theoretical and Applied Mechanics; 2015, 53, 2; 383-394
1429-2955
Pojawia się w:
Journal of Theoretical and Applied Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A Study of the Solubility of Biodegradable Foams of Thermoplastic Starch
Autorzy:
Mitrus, M.
Combrzyński, M.
Kupryaniuk, K.
Wójtowicz, A.
Oniszczuk, T.
Kręcisz, M.
Matysiak, A.
Smurzyńska, A.
Mościcki, L.
Powiązania:
https://bibliotekanauki.pl/articles/123826.pdf
Data publikacji:
2016
Wydawca:
Polskie Towarzystwo Inżynierii Ekologicznej
Tematy:
foams
biodegradable materials
thermoplastic starch
extrusion-cooking
solubility
Opis:
The paper presents the results of a study on the water absorption capacity and solubility of biodegradable starch foams produced with single-screw extruder TS-45 with L/D=12. Two different moulding dies were used: one with a circular hole with the diameter of 3 mm and one with a ring hole with the inner diameter of 5 mm. During the extrusion process, the temperature of the cylinder ranged from 80 to 130°C and the screw speeds applied were: 100 and 130 rpm. For the application of the ring die, it was observed that regardless of the speed of the screw, the use of the raw material of higher moisture content led to the production of materials with higher solubility. As a result, the obtained materials revealed solubility at a level of 40%. The results demonstrate good solubility of the starchy fillers of the packaging, which may indicate their susceptibility to decomposition in the conditions of high ambient humidity. A statistical analysis showed a significant impact of moisture of the raw material on the WSI of starch foams used irrespective of the other parameters of the extrusion-cooking process. The raw material moisture had a significant effect on the water absorption capacity of only TPS foams produced in the ring die at the screw speed of 100 rpm.
Źródło:
Journal of Ecological Engineering; 2016, 17, 4; 184-189
2299-8993
Pojawia się w:
Journal of Ecological Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Evaluation of Properties of Cast Metal Foams with Irregular Inner Structure
Autorzy:
Kroupová, I.
Lichý, P.
Ličev, L.
Hendrych, J.
Souček, K.
Powiązania:
https://bibliotekanauki.pl/articles/355316.pdf
Data publikacji:
2018
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
metal foams
irregular structure
precursor
porosity
micro-CT
Opis:
Internal structure of metal foams is one of the most important factors that determine its mechanical properties. There exists a number of methods for studying the nature of the inner porous structure. Unfortunately most of these processes is destructive and therefore it is not possible to reuse the sample. From this point of view, as a suitable method seems to be the ability of using the so-called X-ray microtomography (also micro-CT). This is a non-destructive methodology used in a number of fields (industry, science, archaeology, medicine) for a description of the material distribution in the space (e.g. pores, fillers, defects, etc.). In principle, this technology works on different absorption of X-ray radiation by materials with changing proton number. The contribution was worked out in collaboration with experts from the Faculty of Electrical Engineering and Computer Science of the VŠB-Technical University of Ostrava and it is focused on the analysis of internal structure of the metal foam casting with irregular arrangement of internal pores by using micro-CT. The obtained data were evaluated in the commercial software VGStudio MAX 2.2 and in the FOTOMNG system. For the evaluation of these data a new specialized module was introduced in this system. Several methods of pre-processing the image was prepared for the measurement. This preliminary processing consists, for example, from a binary image thresholding for better diversity between the internal porosity and the material itself or functions for colour inversion.
Źródło:
Archives of Metallurgy and Materials; 2018, 63, 4; 1847-1851
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effect of starch type and screw speed on mechanical properties of extrusion-cooked starch-based foams
Autorzy:
Combrzyński, M.
Wojtowicz, A.
Mitrus, M.
Oniszczuk, T.
Matwijczuk, A.
Pawelczyk, P.
Mościcki, L.
Powiązania:
https://bibliotekanauki.pl/articles/2082504.pdf
Data publikacji:
2019
Wydawca:
Polska Akademia Nauk. Instytut Agrofizyki PAN
Tematy:
corn starch
potato starch
foams
compression
test
elastic modulus
Opis:
Potato starch and corn starch are popular basic raw materials in the processing of biopolymers. One of the processing methods employed in the manufacture of biopolymers is extrusion-cooking technique. With specific parameters and equipment configurations, it is possible to obtain a wide variety of starch-based biopolymers. Loose fill foams are usually produced with the use of polystyrene, but the adverse environmental effects of conventional plastics provide an incentive for the development of new, environmentally friendly raw materials. The aim of the study was to apply the extrusion-cooking technique to prepare starch-based foams from potato starch and corn starch under various extruder screw speeds applied during processing. Process efficiency and energy consumption were also tested during processing. The expanded foams were analysed by means of cutting and compression tests to evaluate selected mechanical properties. The type of starch used and the processing screw speed had an impact on the efficiency and specific energy requirements of the process. The results showed that the screw speed had a significant effect on the cutting forces in the tested foams as well as on its compression properties. Higher hardness of foams was observed when potato starch was used as the basic raw material. Moreover, corn starch foams proved to be more elastic in compression tests.
Źródło:
International Agrophysics; 2019, 33, 2; 233-240
0236-8722
Pojawia się w:
International Agrophysics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Numerical simulation of energy absorption in polyurethane foams under impact
Autorzy:
Jankowski, M.
Czechowski, L.
Kotełko, M.
Powiązania:
https://bibliotekanauki.pl/articles/241823.pdf
Data publikacji:
2012
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
polyurethane foams
energy absorption
lump mass method
finite element method
Opis:
Selection of proper mechanical characteristics of the padding material of the head rest, namely polyurethane foam, is particularly important in the design process of the vehicle seat head restraint. In the paper the code of numerical simulation of flexible polyurethane foam absorber response against impact of a rigid body (passenger's head) is presented. The code is based on the lump mass method. Basics of the numerical algorithm based on this method are presented. Material constitutive model of flexible polyurethane foam (FPF) derived on the basis of former experimental tests and used in the algorithm is described. Comparative results of numerical simulations together with results of experiments carried out on drop hammer rig with flat impact or are shown. The results are presented on diagrams of deceleration versus time. Also comparative Finite Element simulations are carried out. The FE simulation was performed using the implicit analysis, taking into account the multi-linear, hyper-elastic material model and large strain (non-linear geometric relations). The influence of damping coefficient on the deceleration characteristics was investigated. Some final conclusions concerning the applicability of the numerical code based on the lump mass method, as well as its advantages in comparison with the FE software are derived.
Źródło:
Journal of KONES; 2012, 19, 4; 245-252
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Damping Properties and Density of Helmet Liners Made of Expanded Polystyrene (EPS)
Autorzy:
Trzaskalska, M.
Chwastek, R.
Powiązania:
https://bibliotekanauki.pl/articles/2049565.pdf
Data publikacji:
2021
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
expanded PS
ski liners
PS foams
damping factor
bulk density
Opis:
The purpose of the work was to determine the infuence of the bulk density ρz of granules, processing parameters and the density of ski inserts ρw made of expanded polystyrene (EPS) on their damping properties. For this aim liners for ski helmets with 3 different bulk densities were made. Sintering time and sintering pressure were also changed. The percentage damping factor η was determined on the basis of the results obtained in the rebound resilience test. Based on the analysis of the obtained data, it was found that increasing the density of EPS pads ρw increases their damping properties and at the same time contributes to a decrease in elasticity, increase in hardness and brittleness of EPS products.
Źródło:
Archives of Metallurgy and Materials; 2021, 66, 1; 339-344
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Polyurethane foams with pyrimidine rings
Autorzy:
Kania, E.
Lubczak, J.
Powiązania:
https://bibliotekanauki.pl/articles/778772.pdf
Data publikacji:
2014
Wydawca:
Zachodniopomorski Uniwersytet Technologiczny w Szczecinie. Wydawnictwo Uczelniane ZUT w Szczecinie
Tematy:
barbituric acid
glycidol
alkylene carbonates
oligoetherols
polyurethane foams
thermal stability
Opis:
Oligoetherols based on pyrimidine ring were obtained upon reaction of barbituric acid with glycidol and alkylene carbonates. These oligoetherols were then used to obtain polyurethane foams in the reaction of oligoetherols with isocyanates and water. The protocol of foam synthesis was optimized by the choice of proper kind of oligoetherol and synthetic composition. The thermal resistance was studied by dynamic and static methods with concomitant monitoring of compressive strength. The polyurethane foams have similar physical properties as the classic ones except their enhanced thermal resistance. They stand long-time heating even at 200°C. Moreover thermal exposition of foams results generally in increase of their compressive strength.
Źródło:
Polish Journal of Chemical Technology; 2014, 16, 3; 1-6
1509-8117
1899-4741
Pojawia się w:
Polish Journal of Chemical Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Tall oil based rigid polyurethane foams thermal insulation filled with nanofibrillated cellulose
Sztywne pianki poliuretanowe na bazie oleju talowego napełnione nanofibrylarną celulozą
Autorzy:
Kirpluks, Mikelis
Ivdre, Aiga
Fridrihsone, Anda
Cabulis, Ugis
Powiązania:
https://bibliotekanauki.pl/articles/947341.pdf
Data publikacji:
2020
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Chemii Przemysłowej
Tematy:
rigid polyurethane foams
nanofibrillated cellulose
sztywne pianki poliuretanowe
nanofibrylarna celuloza
Opis:
Two types of biopolyols based on tall oil were used for the preparation of rigid polyurethane (PUR) foams. High functionality biopolyol was synthesized from tall oil fatty acids by epoxidation and subsequent oxirane ring-opening with trimethylolpropane and tall oil esterification with triethanolamine was carried out to obtain low viscosity biopolyol. The optimal dispergation method with sonication was applied to obtain rigid PUR foams with 0–1.5 wt % of nanofibrillated cellulose. The influence of nanofibrillated cellulose content on the rigid PUR foams’ closed-cell content, density, thermal conductivity, compression strength, and compression modulus was evaluated. Addition of NFC fiber into rigid PUR foam structure slightly increased compression strength and Young’s modulus.
Do przygotowania sztywnych pianek poliuretanowych (PUR) napełnionych nanofibrylarną celulozą (NFC) użyto dwa rodzaje biopolioli na bazie oleju talowego. Poliol o dużej funkcyjności syntetyzowano metodą epoksydacji i otwarcia pierścieni oksiranowych trimetylolopropanem, natomiast poliol o małej funkcyjności otrzymano metodą estryfikacji oleju talowego trietanoloaminą. W celu uzyskania równomiernej dyspersji nanofibrylarnej celulozy w sztywnych piankach wykorzystano metodę sonikacji. Zawartość napełniacza wynosiła 0–1.5% mas. Analizowano wpływ dodatku nanofibrylarnej celulozy na zawartość komórek zamkniętych, gęstość, przewodność cieplną, wytrzymałość na ściskanie oraz moduł Younga wytworzonych pianek PUR. Stwierdzono że dodatek NFC powoduje nieznaczne zwiększenie wytrzymałości na ściskanie oraz modułu Younga pianek.
Źródło:
Polimery; 2020, 65, 10; 719-727
0032-2725
Pojawia się w:
Polimery
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Technology of Production of Mold Filling Material for Specific Purposes in the Field of Metallic Foam Casting
Autorzy:
Kroupová, Ivana
Bašistová, Martina
Lichý, Petr
Merta, Václav
Radkovský, Filip
Jezierski, Jan
Powiązania:
https://bibliotekanauki.pl/articles/28099598.pdf
Data publikacji:
2023
Wydawca:
Polska Akademia Nauk. Czasopisma i Monografie PAN
Tematy:
molding mixture
metallic foams
precursor
abrasion loss
3-point bending strength
Opis:
This paper describes the technology for the production of precursors (space holder material) used to form the complex internal structure of cast metal foam. The precursor material must exhibit sufficient refractoriness, resist contact with liquid metal and at the same time should exhibit good collapsibility after casting. With regard to the greening of foundry production, the focus of this paper was on materials that could exhibit the above properties and at the same time do not have a negative impact on the environment. In this paper, the technology for the production of spherical precursors from a self-hardening mixture with a geopolymer-based binder system is described and verified. The motivation for the choice of material and all the sub-steps of the process - molding into the core box, tumbling, including the necessary accompanying tests of the mechanical properties of the core mixture being verified - are described.
Źródło:
Archives of Metallurgy and Materials; 2023, 68, 2; 757--763
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
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