Casting industry has been enriched with the processes of mechanization and automation in production. They offer both better working standards, faster and more accurate production, but also have begun to generate new opportunities for new foundry defects. This work discusses the disadvantages of processes that can occur, to a limited extend, in the technologies associated with mould assembly and during the initial stages of pouring. These defects will be described in detail in the further part of the paper and are mainly related to the quality of foundry cores, therefore the discussion of these issues will mainly concern core moulding sands. Four different types of moulding mixtures were used in the research, representing the most popular chemically bonded moulding sands used in foundry practise. The main focus of this article is the analysis of the influence of the binder type on mechanical and thermal deformation in moulding sands.
The ablation casting technology consists in pouring castings in single-use moulds made from the mixture of sand and watersoluble binder. After pouring the mould with liquid metal, while the casting is still solidifying, the mould destruction (washing out, erosion) takes place using a stream of cooling medium, which in this case is water. The following paper focuses on the selection of moulding sands with hydrated sodium silicate technologies for moulds devoted to the ablation casting of aluminum alloys. It has been proposed to use different types of moulding sands with a water-soluble binder, which is hydrated sodium silicate. The authors showed that the best kind of moulding sands for moulds for Al alloy casting will be moulding sands hardened with physical factors – through dehydration. The use of microwave hardened moulding sands and moulding sands made in hot-box technology has been proposed. The tests were carried out on moulding sands with different types of modified binder and various inorganic additives. The paper compares viscosity of different binders used in the research and thermal degradation of moulding sands with tested binders. The paper analyzes the influence of hardening time periods on bending strength of moulding sands with hydrated sodium silicate prepared in hot-box technology. The analysis of literature data and own research have shown that molding sand with hydrated sodium silicate hardened by dehydration is characterized by sufficient strength properties for the ablation foundry of Al alloys.
W artykule przedstawiono wpływ materiału biodegradowalnego – polikaprolaktonu (PCL) na wybrane właściwości mas formierskich. Do badań wytypowano szeroko stosowaną w praktyce odlewniczej masę samoutwardzalną z żywicą fenolowo-furfurylową oraz przyjazną dla środowiska masę samoutwardzalną z uwodnionym krzemianem sodu. Zadaniem nowego dodatku w przypadku masy z żywicą syntetyczną jest zmniejszenie jej szkodliwości dla otoczenia i zwiększenie elastyczności w temperaturze otoczenia. W przypadku masy z przyjaznym dla środowiska uwodnionym krzemianem sodu zadaniem nowego dodatku jest zwiększenie elastyczności badanej masy przy zachowaniu jej proekologicznego charakteru. Badania wykazały, że zastosowanie do mas formierskich 5% PCL zwiększa elastyczność w temperaturze otoczenia badanych mas zarówno ze spoiwem organicznym, jak i nieorganicznym. Wykazano również wpływ nowego dodatku na deformację mas w podwyższonej temperaturze.
EN
The article presents the influence of biodegradable material - polycaprolactone (PCL) on selected properties of molding sands. For the tests two different moulding sands were chosen. A self-hardening moulding sand with phenol-furfuryl resin and an environmentally friendly self-hardening moulding sand with hydrated sodium silicate, both of which are widely used in foundry practice. The task of the new additive for moulding mixtures with synthetic resins is to reduce its harmfulness to the environment and increase the elasticity at ambient temperature. In the case of the moulding sand with environmentally friendly hydrated sodium silicate, the task of the new additive is to increase the elasticity of the test sand while maintaining its ecological character. The research has shown that the use of 5% PCL for molding sands increases their flexibility at the ambient temperature, both with organic and inorganic binders. The influence of the new additive on the moulding sand deformation at elevated temperature was also demonstrated in the research.
The progressive mechanization and automation of industrial equipment is the driving force of progress, not only in the field of production but also in the measuring and control equipment. In mold production, the automation of processes such as forming molds and cores along with their assembly has led to increases in serial production, reductions in defects, and the shortening of molding times, among others. Thanks to automation in mold and core departments and the use of all sorts of manipulators, mold production in foundries has gained momentum. Unfortunately, in addition to the mentioned advantages, there are also new challenges as to the quality and properties of the molding and core sands used in highly automated foundries.This article presents recent research on molding sand elasticity. The topic was introduced as an attempt to answer the new needs of highly mechanized foundries. The article discusses a new method of measuring the resistance of molding materials to undergoing mechanical deformation (molding sand elasticity), with an additional analysis of the bending strengths of the tested samples. Precise measurements, test sample preparation, and interpretation of the received results are presented in the article.
Jednym z problemów analiz ilości związków biogennych w wodach powierzchniowych w Polsce jest niewielka ilość danych monitoringowych pochodzących głównie z Państwowego Monitoringu Środowiska, w którym częstotliwość wykonywania badań jest ciągle zbyt mała, aby można było uchwycić zmienność stężenia tych pierwiastków na przestrzeni czasu, a tym samym określić reprezentatywną ilość azotu ogólnego i fosforu ogólnego w wybranym profilu. W artykule przedstawiono wyniki eksperymentu, jaki przeprowadzono w 2014 r. w jednym z profili poprzecznych rzeki Słupi - pobierano na nim próby wody w stałych odstępach czasu przez trzy doby, a następnie oznaczono w nich stężenia azotu ogólnego i fosforu ogólnego. Eksperyment ten miał na celu analizę czasową i przestrzenną rozkładu stężeń biogenów w profilu poprzecznym rzeki i tym samym odpowiedź na pytanie czy dotychczasowe dane dotyczące stężenia biogenów mogą być użyteczne do kalibracji środowiskowych modeli matematycznych i jaki ewentualny błąd wyników modelowania wynikający z rozrzutu wyników należy założyć.
EN
One of the problems encountered during analyses of biogenic compounds in surface waters in Poland is scarce amount of monitoring data, originating mainly from the State Environmental Monitoring, where the frequency of research is still too Iow in order to grasp the variability of concentration of those elements in time and thus determine the representative quantity of total nitrogen and phosphorus in a selected profile. The artide presents the results of an experiment carried out in 2014 in one of the Słupia River transversal profiles- it consisted in collecting samples of water in fixed time intervals for three days and then determine the concentration of total nitrogen and total phosphorus. The goal of the experiment was to analyse the time and spatial distribution of biogenes in the river transversal profile and thus answer the question whether the hitherto data on concentration of biogenes may be useful in calibration of environmental mathematical models and what possible error in the modelling results, resulting from the results spread, should be assumed.
Zagrożenia, jakie wywołuje zmieniający się klimat, stają się coraz bardziej realne, a ich skutki zaczynają być odczuwalne zarówno w skali globalnej, jak i lokalnej. Nasilają się zjawiska wcześniej nietypowe, takie jak: fale upałów, susze, gwałtowne burze czy powodzie opadowe. Modele klimatyczne, poza wzrostem temperatury powietrza, wskazują na zmianę schematu opadów, co z kolei będzie miało przełożenie na wiele procesów zachodzących w zlewniach rzecznych, takich jak erozja odpowiedzialna za przedostawanie się rumowiska do wód. Wraz z rumowiskiem, które ma silne właściwości sorpcyjne, do wód przedostaną się również zanieczyszczenia mogące istotnie wpłynąć na jakość wód zlewni. Istnieje zatem niebezpieczeństwo wzrostu zanieczyszczenia rzek na skutek zmian klimatu. W artykule przedstawiono dotychczasowy stan wiedzy w tym zakresie oraz opisano narzędzia do oceny ilości i jakości rumowiska unoszonego, jakimi są opracowany w IMGW-PIB makromodel DNS oraz metodę znaczników geochemicznych (sediment fingerprinting).
EN
Threats related to the changing climate are increasingly real, and their effects start to be visible at the global, as well as local scale. The phenomena that used to be atypical, such as heat waves, droughts, violent storms or torrential floods, are intensifying. Besides the air temperature rise, climate models indicate a change in the precipitations scheme, which will in turn impact many processes taking place in river catchment areas, such as erosion responsible for transfer of the debris to waters. The debris, having strong sorption properties, may carry pollution to the catchment area waters, which may significantly affect its quality. The climate change may therefore lead to the poltution of rivers. The article presents the current knowledge about this phenomenon and describes the tools for evaluation of the quantity and quality of the floating river load, such as the DNS macromodel elaborated in the Institute of Meteorology and Water Management, National Research Institute and the sediment fingerprinting method.
Despite the numerous measures taken to protect its environment for many years, Poland is among the top countries with the largest contributing share in the pollution of the Baltic Sea. It is undoubtedly the case that we are dealing with excesses in the permissible concentrations of total nitrogen (TN) and total phosphorus (TP) on many sections of Polish rivers. However, in order to be able to thoroughly analyze this problem, it is first necessary to increase the frequency of TN and TP monitoring in surface waters. The article presents the first results obtained from the TN and TP monitoring system launched in 2016 at the IMGW-PIB on the calculation profile Szczecin (the Odra River) and Tczew (the Vistula River). The on-line analyzers installed for this purpose make it possible to perform measurements several times a day, allowing for the assessment of diurnal and seasonal variations of TN and TP. Using the results obtained, the daily values of the River Absorption Capacity (RAC) parameter were also calculated. The obtained results showed that, in general, the value of the RAC parameter on the analyzed calculation profiles was positive for both TN and TP throughout the entire period, irrespective of the time of year.
The constant growth of foundry modernization, mechanization and automation is followed with growing requirements for the quality and parameters of both moulding and core sands. Due to this changes it is necessary to widen the requirements for the parameters used for their quality evaluation by widening the testing of the moulding and core sands with the measurement of their resistance to mechanical deformation (further called elasticity). Following article covers measurements of this parameter in chosen moulding and core sands with different types of binders. It focuses on the differences in elasticity, bending strength and type of bond destruction (adhesive/cohesive) between different mixtures, and its connection to the applied bonding agent. Moulding and cores sands on which the most focus is placed on are primarily the self-hardening moulding sands with organic and inorganic binders, belonging to the group of universal applications (used as both moulding and core sands) and mixtures used in cold-box technology.
The essence of ablation casting technology consists in pouring castings in single-use moulds made from the mixture of sand and a water-soluble binder. After pouring the mould with liquid metal, while the casting is still solidifying, the mould destruction (washing out, erosion) takes place using a stream of cooling medium, which in this case is water. This paper focuses on the selection of moulding sands with hydrated sodium silicate for moulds used in the ablation casting. The research is based on the use of Cordis binder produced by the Hüttenes-Albertus Company. It is a new-generation inorganic binder based on hydrated sodium silicate. Its hardening takes place under the effect of high temperature. As part of the research, loose moulding mixtures based on the silica sand with different content of Cordis binder and special Anorgit additive were prepared. The reference material was sand mixture without the additive. The review of literature data and the results of own studies have shown that moulding sand with hydrated sodium silicate hardened by dehydration is characterized by sufficient strength properties to be used in the ablation casting process. Additionally, at the Foundry Research Institute in Krakow, preliminary semi-industrial tests were carried out on the use of Cordis sand technology in the manufacture of moulds for ablation casting. The possibility to use these sand mixtures has been confirmed in terms of both casting surface quality and sand reclamation.
The paper presents the impact of biodegradable material - polycaprolactone (PCL) on selected properties of moulding sands. A self-hardening moulding sands with phenol-furfuryl resin, which is widely used in foundry practice, and an environmentally friendly self-hardening moulding sand with hydrated sodium silicate where chosen for testing. The purpose of the new additive in the case of synthetic resin moulding sands is to reduce their harmfulness to the environment and to increase their “elasticity” at ambient temperature. In the case of moulding sands with environmentally friendly hydrated sodium silicate binder, the task of the new additive is to increase the elasticity of the tested samples while preserving their ecological character. Studies have shown that the use of 5% PCL in moulding sand increases their flexibility at ambient temperature, both with organic and inorganic binders. The influence of the new additive on the deformation of the moulding sands at elevated temperatures has also been demonstrated.
The constantly developing and the broadly understood automation of production processes in foundry industry, creates both new working conditions - better working standards, faster and more accurate production - and new demands for previously used materials as well as opportunities to generate new foundry defects. Those high requirements create the need to develop further the existing elements of the casting production process. This work focuses on mechanical and thermal deformation of moulding sands prepared in hot-box technology. Moulding sands hardened in different time periods were tested immediately after hardening and after cooling. The obtained results showed that hardening time period in the range 30-120 sec does not influence the mechanical deformation of tested moulding sands significantly. Hot distortion tests proved that moulding sands prepared in hot-box technology can be characterized with stable thermal deformation up to the temperature of circa 320 °C.
The parameter River Absorption Capacity (RAC) is understood as the load of pollutants introduced into a given river section which will not cause permanent and irreversible changes in the aquatic ecosystem nor change the classification of water quality in a given river calculation profile. The paper presents a method of determining the RAC using the Macromodel DNS/SWAT developed at IMGW-PIB. The selection of an appropriate inviolable flow plays an important role in calculating RAC. Therefore, the article presents the calculations for the three different non-invasive flows: Mean low flow (MLF – the Kostrzewa method), 7Q10 and Tennant. The results obtained in these ways are different from each other. The concept of ‘environmental flows’ continues to evolve in response to these challenges, emphasizing aquatic and riparian ecosystems as legitimate water users within an Integrated Water Resources Management. The analysis has shown that the choice of relevant data for environmental computation is decisive and the use of purely statistical methods to protect biological life in rivers is insufficient. Thus, the use of environmental flows to better describe the specifics of the analyzed basins seems to be most beneficial.
PL
Celem pracy było określenie wpływu wybranych przepływów nienaruszalnych na otrzymany wynik chłonności rzeki poszczególnych JCWP na zlewni Warty środkowej. Do osiągnięcia tego celu wykorzystano wyniki uzyskane z Makromodelu DNS/SWAT i trzech różnych metod obliczania przepływu nienaruszalnego: metoda Kostrzewy, przepływ 7Q10 i przepływ środowiskowy Tennanta. Wykorzystanie modelu SWAT jako modułu Makromodelu DNS znacznie rozszerzyło jego możliwości i pozwoliło obliczyć parametr RAC. Użycie SWAT pozwoliło na podzielenie analizowanej zlewni na poszczególne JCWP, a następnie wprowadzenie do modelu bardzo szczegółowych danych dotyczących zlewni. Makromodel DNS/SWAT pozwolił uzyskać dane o stężeniach i ładunkach zanieczyszczeń dla wszystkich siedemdziesięciu profili zamykających JCWP. Zlewnią wybraną do badań była Warta środkowa pomiędzy profilami Nowa Wieś Podgórna i Oborniki na której zlokalizowanych jest 70 JCWP. W pierwszej kolejności obliczono ładunki zanieczyszczeń wykorzystując metodę Kostrzewy, a następnie kolejne dwie metody. Otrzymane wartości ładunków zanieczyszczeń posłużyły do obliczeń chłonności rzeki (RAC). W przypadku azotu ogólnego dla każdego z wybranych przepływów nienaruszalnych tylko trzy JCWP uzyskały ujemne wartości chłonności. W przypadku fosforu ogólnego aż 11 JCWP uzyskało ujemną wartość chłonności. Ujemną wartość chłonności dla fosforu ogólnego uzyskały m.in. JCWP zlokalizowane poniżej miasta Poznania. Wybór odpowiedniej metody obliczania przepływu nienaruszalnego ma kluczowe znaczenie dla obliczeń środowiskowych takich jak wyznaczanie chłonności rzeki. Wybór zbyt restrykcyjnego przepływu nienaruszalnego może mieć negatywne skutki dla całej zlewni.
The aim of the article is thermal and structural analysis of new two-component binders for foundry moulding sands. The previous research showed the possibility of using biodegradable materials as binders or parts of binders’ compositions for foundry moulding and core sands. This paper is concentrated on estimating the influence of PCL on phenol-furfuryl resin thermal destruction (measured by derivatographic research) and its structure (measured by FTiR technology). The research proved that addition of new biodegradable additive PCL in the amount of 5-15% to the phenol-furfuryl resin doesn’t change the resin thermal destruction course but it results in appearance of a new band in two-component binder structure. What’s more there has been noticed a growth of intensity for band at wavenumber 1730 cm-1 (C = O) with the increasing addition of PCL.
In the foundry industry, as in many other fields we seek to achieve the best quality with the least losses and the lowest cost. To meet these demands numerous plants increased automatization of their manufacturing processes. However, with changes in the production process it is necessary to change also the materials used. Not only casting alloys that are used in production, but also applied moulding and core sands are important. Proper selection and evaluation of the properties of used moulding mixtures is crucial in order to achieve a highly efficient production. In this article a new issue concerning the use of flexibility in foundry molding and core was mentioned. It explains the principles of measurement and interpretation of the obtained results for the cold-box moulding sands.
This paper focuses on mechanical properties of self hardening moulding sands with furfuryl and alkyd binders. Elasticity as a new parameter of moulding sands is investigated. With the use of presented testing equipment it is possible to determine force kinetics and deformation of moulding sand in real time. The need for this kind of study comes from the modern casting industry. New foundries can be characterized with high intensity of production which is correlated with high level of mechanization and automatization of foundry processes. The increasingly common use of manipulators in production of moulds and cores can lead to generation of new types of flaws, caused by breakage in moulds and cores which could occur during mould assembly. Hence it is required that moulds and cores have high resistance to those kinds of factors, attributing it with the phenomenon of elasticity. The article describes the theoretical basis of this property, presents methods of measuring and continues earlier research.
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W artykule przedstawiono opis nowego stanowiska do pomiaru odporności mas formierskich na odkształcenia mechaniczne (elastyczność) oraz termiczne (hot distortion). Szczegółowo wyjaśniono zasady pomiaru, sposób przygotowania próbek do badań oraz opis i interpretację otrzymanych wyników.
EN
The article describes a new measuring station focused on the resistance of molding sands to mechanical (elasticity) and thermal (hot distortion) deformation. The principles of the measurement, how to prepare the samples for testing, as well as the description and interpretation of the results, are explained in detail.
Rosnące wymagania dotyczące emisji substancji szkodliwych zmuszają przemysł odlewniczy do poszukiwania nowych, bardziej przyjaznych dla środowiska rozwiązań. Do rozwiązań takich mogą należeć: technologie sporządzania mas formierskich i rdzeniowych z zastosowaniem organicznych materiałów biodegradowalnych jako spoiw. Należy jednak pamiętać, że nowe technologie muszą zapewnić wysokie właściwości technologiczne mas formierskich i rdzeniowych. W niniejszym artykule przedstawiono wyniki badań nowych dwuskładnikowych spoiw formierskich, w których część powszechnie stosowanej w praktyce odlewniczej żywicy fenolowo-furfurylowej zastąpiono materiałem biodegradowalnym w postaci polikaprolaktonu (PCL). W artykule przedstawiono badania wpływu materiału biodegradowalnego jako komponentu nowego dwuskładnikowego spoiwa na degradację termiczną spoiwa, jego lepkość oraz na wybrane właściwości technologiczne badanych mas z zastosowaniem nowego spoiwa, w tym ich deformację cieplną oraz elastyczność w temperaturze otoczenia. Przeprowadzone badania wykazały, że zastąpienie w spoiwie części żywicy fenolowo-furfurylowej materiałem biodegradowalnym PCL nie wpływa na degradację termiczną nowego spoiwa, zwiększa natomiast jego lepkość. Masy z zastosowaniem dwuskładnikowego spoiwa charakteryzują się zbliżonymi właściwościami technologicznymi do mas zawierających tylko żywicą fenolowo-furfurylową.
EN
The increasing requirements concerning the emission of hazardous substances force the casting industry to search for new, more environment-friendly solutions. Such solutions may include technologies of developing moulding and core sands with the use of organic biodegradable materials as binders. We should, however, remember that the new technologies must ensure high technological properties of the moulding and core sands. This article presents the results of investigations of new binary moulding binders, where part of the phenol-furfuryl resin commonly applied in casting, was replaced by a biodegradable material in the form of polycaprolactone (PCL). The article discusses the investigations of the effect of the biodegradable material as a component of a new binary binder on the thermal degradation of the binder, its viscosity as well as the selected technological properties of the examined moulding sands, including their thermal deformation and elasticity at ambient temperature. The performed examinations showed that replacing a part of the phenol- furfuryl resin in the binder with the PCL biodegradable material does not affect the thermal degradation of the new binder, while increasing its viscosity. The moulding mixtures with the applied binary binder are characterized by similar technological properties to the moulding sands with the phenol-furfuryl resin only.
Growing emission requirements are forcing the foundry industry to seek new, more environmentally friendly solutions. One of the solutions may be the technologies of preparing moulding and core sands using organic biodegradable materials as binders. However, not only environmental requirements grow but also those related to the technological properties of moulding sand. Advancing automation and mechanization of the foundry industry brings new challenges related to the moulding sands. Low elasticity may cause defects during assembly of cores or moulds by the manipulators. The paper presents the study of flexibility in the room temperature according to new method and resistance to thermal deformation of self-hardening moulding sands with furfuryl resin, containing biodegradable material PCL. The task of the new additive is to reduce the moulding sands harmfulness to the environment and increase its flexibility in the room temperature. The impact of the additive and the effect of the amount of binder on the properties of mentioned moulding sands were analysed. Studies have shown that the use of 5% of PCL does not change the nature of the thermal deformation curve, improves the bending strength of tested moulding mixtures and increases their flexibility at room temperature.
W artykule zostały przedstawione stosowane laboratoryjne metody pomiaru wybijalności mas. Zaproponowano nową metodę oceny tej właściwości, której zalety wykazano, testując zmodyfikowane przez autorów odlewnicze masy formierskie z uwodnionym krzemianem sodu. Masy te cechuje mała szkodliwość dla środowiska, niestety ich wady to zła wybijalność oraz mała zdolność do regeneracji mechanicznej.
EN
The article presents commonly used methods of measuring moulding sands knock-out properties. A new method of estimation of this parameter is presented, its’ advantages are proved by tests of modified foundry moulding sands with hydrated sodium silicate. They are environmentally friendly, but unfortunatelythey have bad knock-out properties and low mechanical reclamation ability.
The article shows the influence of environment requirements on changes in different foundry moulding sands technologies such as cold box, self-hardening moulding sands and green sands. The aim of the article is to show the possibility of using the biodegradable materials as binders (or parts of binders’ compositions) for foundry moulding and core sands. The authors concentrated on the possibility of preparing new binders consisting of typical synthetic resins - commonly used in foundry practice - and biodegradable materials. According to own research it is presumed that using biodegradable materials as a part of new binders’ compositions may cause not only lower toxicity and better ability to reclaim, but may also accelerate the biodegradation rate of used binders. What’s more, using some kinds of biodegradable materials may improve flexibility of moulding sands with polymeric binder. The conducted research was introductory and took into account bending strength and thermal properties of furan moulding sands with biodegradable material (PCL). The research proved that new biodegradable additive did not decrease the tested properties.
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