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1
Content available The Influence of Moulding Sand Type on Mechanical and Thermal Deformation
Grabarczyk A., Major-Gabryś K., Dobosz S. M., Jakubski J., Bolibruchová D., Brůna M., Pastirčák R.
Archives of Metallurgy and Materials
|
2019
|
Vol. 64, iss. 1
347--351
EN
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.
2
Content available Discussion on the Methodology and Apparatus for Hot Distortion Studies
Ignaszak Z.
Archives of Foundry Engineering
|
2018
|
Vol. 18, iss. 2
141--145
EN
The paper refers to earlier publications of the author, on identification of properties of thermomechanical, chemically hardened core/mold sands. In that earlier period, first version of the original DMA apparatus, produced by a Polish company Multiserw-Morek, was used. The Hot Distortion (HD) study results, published by the author in 2008, referred to phenomena accompanying a thermal shock in real conditions of thermal interaction of a liquid alloy on a mold, in reference to a shock possible to obtain in laboratory conditions, without use of liquid alloy as a heat source, with analysis of solutions applied in the DMA apparatus. This paper presents author’s observations on testing a new, innovative version of the LRu-DMA apparatus, containing a module allowing the Hot Distortion (HD) study. Temperature of specimens achieved in the case of the gas burner heating reaches values definitely above 800°C on the heated side and 610°C on the other side. Using an electric radiator, with maximal temperature of 900°C allows obtaining temperatures in between 225-300°C.
3
Content available Compaction of Cores Made by Blowing Methods – Model Investigations
Dańko R.
Archives of Foundry Engineering
|
2018
|
Vol. 18, iss. 2
191--197
EN
The results of model investigations of the influence of the blowing process selected parameters on the distribution of the compaction of the core made by the blowing method, are presented in the hereby paper. These parameters were: shooting pressure, shooting hole diameter, amount and distribution of deaerating holes. Investigations were performed using the horizontal core box of the cuboidal cavity and the same core box into which inner inserts were introduced. These inserts were dividing the primary volume into three sectors differing in their direction, introduction conditions and the character of the core sand flow. As the compaction measure the apparent sand density was assumed. The density was determined in five measuring points in case of uniform cores, and in three measuring points in case of cores obtained in the core box with three separated sectors. The apparent density of the compacted core sand in the core box cavity was determined on the basis of the measurements of masses and volumes of samples cut-out from the determined core places by means of the measuring probe. Investigations were performed at three values of the working pressure equal 0.4, 0.5 and 0.6MPa for two diameters of the shooting hole: 10 and 20 mm. During tests the core box deaeration, controlled by an activisation of the determined number of deaerating vents placed in the core box, was also subjected to changes.
4
Content available Validation of the Theoretical Model of Determining the Strength of Cores Made by the Blowing Method
Dańko R.
Archives of Foundry Engineering
|
2017
|
Vol. 17, iss. 3
27--30
EN
Core sands for blowing processes, belong to these sands in which small amount of the applied binding material has the ability of covering the sand matrix surface in a way which - at relatively small coating thickness - allows to achieve the high strength. Although the deciding factor constitute, in this aspect, strength properties of a binder, its viscosity and ability to moisten the matrix surface, the essential meaning for the strength properties of the prepared moulding sand and the mould has the packing method of differing in sizes sand grains with the coating of the binding material deposited on their surfaces. The knowledge of the influence of the compaction degree of grains forming the core on the total contact surface area can be the essential information concerning the core strength. Forecasting the strength properties of core sands, at known properties of the applied chemically hardened binder and the quartz matrix, requires certain modifications of the existing theoretical models. They should be made more realistic with regard to assumptions concerning grain sizes composition of quartz sands and the packing structure deciding on the active surface area of the contacts between grains of various sizes and - in consequence - on the final strength of cores.
5
Content available Influence of the Matrix Grain Size on the Apparent Density and Bending Strength of Sand Cores
Dańko R.
Archives of Foundry Engineering
|
2017
|
Vol. 17, iss. 1
27--30
EN
The results of investigations of the influence of the matrix grain sizes on properties of cores made by the blowing method are presented in the hereby paper. Five kinds of matrices, differing in grain size compositions, determined by the laser diffraction method in the Analysette 22NanoTec device, were applied in investigations. Individual kinds of matrices were used for making core sands in the Cordis technology. From these sands the shaped elements, for determining the apparent density of compacted sands and their bending strength, were made by the blowing method. The shaped elements (cores) were made at shooting pressures being 3, 4 and 5 atn. The bending strength of samples were determined directly after their preparation and after the storing time of 1 hour.
6
Content available Badania regeneracji termiczno-mechanicznej mieszaniny mas zużytych typu organicznego i nieorganicznego
Dańko R., Łucarz M., Dańko J.
Archives of Foundry Engineering
|
2015
|
Vol. 15, iss. 4 spec.
15--18
PL
Celem przeprowadzonych badań było określenie możliwości regeneracji mieszaniny zużytych mas rdzeniowych pochodzących z procesów warm-box i technologii piasków otaczanych (Croninga), z dodatkiem zużytej masy klasycznej z bentonitem. Ze względu na rodzaj badanych mas zużytych poddano je regeneracji kombinowanej termiczno-mechanicznej, z wykorzystaniem stanowisk doświadczalnych zainstalowanych w Hali Maszyn Odlewniczych Wydziału Odlewnictwa AGH. Efekt regeneracji określany był poprzez badanie straty prażenia uzyskanego regeneratu, morfologii powierzchni ziaren oraz wytrzymałości na zginanie próbek mas formierskich, wykonanych z masy na osnowie regeneratu zagęszczanej metodą nadmuchiwania na stanowisku doświadczalnym PS-1 w technologii warm-box, po czasie odstawania próbek wynoszącym 1h.
EN
The aim of the study was to determine the possibility of reclamation of used core sands mixtures originated from the processes of warm-box and croning with the addition of the classical sand with bentonite. Due to the nature of studied sands combined thermal and mechanical regeneration was performed, with the use of experimental stands installed at the Foundry Engineering Faculty of AGH University of Science and Technology. The effects of reclamatiom process were determined by studying the loss on ignition of the reclaim, as well as the particle surface morphology and a bending strength of samples prepared according to warm-box core molding sands technology, performed using the laboratory PS-1 blower.
7
Content available Assessment of Core Sands Properties in Blowing Process
Dańko R.
Archives of Foundry Engineering
|
2015
|
Vol. 15, iss. 2 spec.
13--16
EN
The effects of filling the core box cavity and sand compaction in processes of core production by blowing methods (blowing, shooting) depend on several main factors. The most important are: geometrical parameters of cavity and complexity of its shape, number, distribution and shape of blowing holes feeding sands as well as the venting of a technological cavity. Values of individual parameters are selected according to various criteria, but mostly they should be adjusted to properties of the applied core sand. Various methods developed by several researchers, including the authors own attempts, allow to assess core sands properties on the basis of special technological tests projecting the process into a laboratory scale. The developed criteria defining a degree or a filling ability factor provide a better possibility of assessing the core sand behaviour during flowing and core box filling, which indicate the value and structure of the obtained compacting decisive – after hardening – for strength and permeability. The mentioned above aspects are analysed – on the basis of authors’ own examinations - in the hereby paper.
8
Content available Influence of the Reclaim from the Cordis Technology on the Core Sand Strength
Dańko J., Dańko R., Skrzyński M., Dereń M., Zygmunt Ł
Archives of Foundry Engineering
|
2014
|
Vol. 14, iss. 4
17--20
EN
The investigation results of the mechanical reclamation of spent moulding sands from the Cordis technology are presented in the paper. The quality assessment of the obtained reclaim and the influence of the reclaim fraction in a matrix on the core sand strength is given. The reclaim quality assessment was performed on the basis of the determination of losses on ignition, Na2O content on reclaim grains and pH values. The reclaim constituted 100%, 75% and 50% of the core sand matrix, for which the bending strength was determined. The matrix reclamation treatment was performed in the experimental rotor reclaimer RD-6. Spent sands were applied in as-delivered condition and after the heating to a temperature of 140 oC. Shaped samples for strength tests were made by shooting and hardening of sands in the warmbox technology.
9
Content available Elution of mixed moulding sands with the GEOPOL binder and core sands with the phenolic resin
Holtzer M., Żymankowska-Kumon S., Dańko R., Kmita A.
Archives of Foundry Engineering
|
2013
|
Vol. 13, iss. 4
53--56
EN
Out of moulding and core sands used in the foundry industry, sands with organic binders deserve a special attention. These binders are based on synthetic resins, which ensure obtaining the proper technological properties and sound castings, however, they negatively influence the environment. Depending on the kind of the applied resin under an influence of a temperature such compounds as for example BTEX group and polycyclic aromatic hydrocarbons (PAHs) can be formed and released. During storing or economic utilization of used sand is possibility of eluting harmful substances into the environment. Therefore at assessing an influence of the used sand on the environment two above elements should be taken into consideration. Only such investigations provide the complete assessment of the given sand harmfulness.
10
Content available Innovative microwave hardening of water-glass containing sandmixes in technical-economic approach
Małachowska A., Stachowicz M., Granat K.
Archives of Foundry Engineering
|
2012
|
Vol. 12, iss. 1
75-80
EN
In recent years, observed is increasing interest in sandmixes containing inorganic binders. These binders, including also water-glass, are harmless for the environment, neutral for humans and relatively cheap. In spite of numerous advantages, their wide application is restricted by poor knock-out properties and problems related to rebonding. Therefore, numerous researches aimed at eliminating disadvantages of water-glass binder are directed, among others, to modifying structure of hydrated sodium silicate or to applying new hardening techniques. The innovative method of rapid hardening by microwave heating, that permits restricting quantity of used binder and thus improving knock-out properties, meets expectations of present-day foundries. In this paper, compiled is available information on microwave hardening of water-glass containing sandmixes, as well as costs of practical application of this technology are evaluated on the ground of own research.
11
Autorskie badania nad doskonaleniem mas formierskich i rdzeniowych
Dobosz S. M., Jelinek P., Major-Gabryś K.
Przegląd Odlewnictwa
|
2011
|
Vol. 61, nr 5-6
196-208
PL
rtykuł prezentuje fragmenty badań własnych autorów nad alternatywnymi rozwiązaniami mas formierskich i rdzeniowych. Celem tych badań jest wskazanie nowych kierunków w zakresie systemów wiązania mas z zastosowaniem spoiw o charakterze nieorganicznym i innych zapewniających niską szkodliwość tych mas dla środowiska. Oczywiście powinny one także spełniać wysokie wymogi technologiczne. Część z zaprezentowanych rozwiązań zostało już z powodzeniem zastosowanych w praktyce przemysłowej, inne są dopiero w fazie badań laboratoryjnych. Poszukiwanie alternatywnych rozwiązań, aktualnie bardzo szeroko rozpowszechnionych systemów z zastosowaniem żywic syntetycznych, jest koniecznością współczesnego odlewnictwa. Dotychczasowa współpraca polskich i czeskich ośrodków naukowych może te prace istotnie zintensyfikować.
EN
The paper presents fragments of authors' investigations on alternative solutions of moulding and core sands. The aim of these studies is to indicate new directions in moulding sands bonding systems with using inorganic (and others) binding materials ensuring a low environmental harmfulness. They should, of course, also meet high technological requirements. A part of the presented solutions have been already successfully applied in an industrial practice, others are at the laboratory examination stage. Searching for alternative solutions, for currently commonly applied systems with synthetic resins, is the necessity of the contemporary foundry engineering. The co-operation of the Polish and Czech research centres can significantly intensify these studies.
12
Content available remote Effective cross-section area of a shooting valve in core shooting machines
Dańko J., Dańko R.
Archives of Foundry Engineering
|
2010
|
Vol. 10, iss. 1 spec.
243--246
13
Content available remote Badanie regeneracji termicznej zużytej masy z technologii hot-box
Łucarz M.
Archives of Foundry Engineering
|
2010
|
Vol. 10, iss. 2 spec.
99--102
PL
W publikacji podjęto próbę określenia liczby cykli regeneracji termicznej, którym może być poddana osnowa ziarnowa wiązana różnymi spoiwami bez znaczącego spadku właściwości wytrzymałościowych. Badania zrealizowano na trzech żywicach stosowanych w technologii hot-box. Wytworzone rdzenie poddawano badaniom wytrzymałościowym, a powstały złom materiałowy kruszono i regenerowano termicznie. Na bazie otrzymanego regeneratu sporządzano nową masę rdzeniową i wykonano rdzenie do badań wytrzymałościowych. Proces powtórzono 9 krotnie. Po każdym cyklu regeneracji termicznej analizowano również odczyn pH osnowy kwarcowej. W wyniku przeprowadzonych badań stwierdzono chemiczny wpływ spoiwa na osnowę ziarnową, który nie daje się w pełni wyeliminować stosując tylko regenerację termiczną. Wprowadzenie uzupełniającego zabiegu regeneracji mechanicznej po obróbce cieplnej może usunąć gromadzące się zanieczyszczenia (w nierównościach regeneratu), które istotnie wpływają na odczyn chemiczny odzyskiwanego materiału.
EN
The aim of the paper was to determine the number of cycles of thermal reclamation to which a silica sand grain bonded by different binders can be subjected with no significant deterioration in strength. The research was carried out on three resins used in hot-box technology. The cores created in this way were subjected to strength tests and the resulting scrap was crushed and reclaimed thermally. The new core sand and cores needed for strength tests were made on the basis of the reclaimed material. The process was repeated nine times. The pH reaction of quartz matrix was analysed after each cycle of thermal reclamation. It was observed that there is an impact of the binder on a silica sand grain. It was concluded that it cannot be fully eliminated by merely using thermal reclamation. The application of additional mechanical reclamation after heat processing can lead to removing the impurities which gather in the irregularities of the reclaimed material and have a significant influence on its chemical reaction.
14
Content available remote Recykling mas odlewniczych u źródła powstawania odpadów przemysłowych
Tabor A.
Zeszyty Naukowe Politechniki Rzeszowskiej. Mechanika
|
2009
|
z. 77 [269]
73-77
PL
W małych i średnich przedsiębiorstwach przyjęto strategię regeneracji podstawowych materiałów eksploatacyjnych w procesach odlewniczych, którymi są masy formierskie i rdzeniowe, u źródła powstawania odpadów. Opracowano proces technologiczny utylizacji polegający na prażeniu zużytej masy odlewniczej, zawierającej żywice syntetyczne jako lepiszcze. Przewidziano odzysk ciepła odpadowego i jego utylizację poprzez kąpiele technologiczne. W tym celu zaprojektowano prototyp doświadczalny komorowego pieca obrotowego. Urządzenie to występuje w trzech wielkościach dostosowanych do potrzeb danego zakładu produkcyjnego. Zaprojektowano też zestaw maszyn towarzyszących, w skład których wchodzą: wyparka, krystalizator i suszarka, a także mieszalnik, granulator i brykieciarka.
EN
A strategy has been developed to implement in small and medium enterprises the reclamation of one of the main foundry materials, i.e. the sand from moulding and core mixtures, right at the source of the waste formation. A technological process of utilization through roasting of the waste foundry moulding and core sands with synthetic resins as a binder was developed. The waste heat recovery and utilization in a sewage-free industrial bath was provided. For the execution of thermal treatment, a prototype rotary chamber furnace was designed. The design included three different sizes of the plant, thus making it well-tailored to the individual needs of production enterprises. A system of the accompanying installations has also been designed, including an evaporator, a crystallizer, a drier, a mixer, a granulator and briquetting machines.
15
Content available remote Assessment of core sands suitability for filling the core box and for compaction - by blowing methods
Dańko J., Dańko R.
Archives of Foundry Engineering
|
2009
|
Vol. 9, iss. 1
37-40
EN
The obtained effects of filling the core box cavity and moulding sand compaction in processes of core production by blowing methods (blowing, shooting) depend on several factors. The most important are: geometrical parameters of cavity and complexity of its shape, number, distribution and shape of holes feeding sands as well as the way of deaeration of a technological cavity. Values of individual parameters are selected according to various criteria, but first of all, they should be adjusted to properties of the applied core sand. One of the ways of a preliminary estimation of suitability of a core sand for filling the core box and for compaction by means of blowing methods is the determination of its fluidity and assessment how this parameter is changing when core sand is awaiting to be shot. Another criterion of suitability of core sands for the blowing process is their apparent density obtained at filling the testing core box of a complicated shape (Boenisch test). Various methods developed by several researchers, including the authors, allow to assess the tested property on the basis of special technological tests projecting the process into a laboratory scale. The developed criteria defining a degree or a filling ability factor provide a better possibility of assessing the core sand behaviour during flowing and core box filling, which indicate the value and structure of the obtained compacting decisive - after hardening - for strength and permeability. The mentioned above aspects were analysed - on the basis of authors' own examinations - in the hereby paper.
16
Content available remote Wpływ powłoki ochronnej na zjawiska cieplne w rdzeniach odlewniczych
Jakubski J., Dobosz S. M.
Archiwum Odlewnictwa
|
2006
|
R. 6, nr 18/2
453--458
PL
W artykule przedstawiono wyniki badań dotyczące wpływu powłok ochronnych na zachowanie się rdzeni formierskich w podwyższonych temperaturach. Jako kryterium oceny zastosowano parametr hot distortion. Otrzymane wyniki badań pokazują, że nie tylko rodzaj osnowy ma wpływ na zachowanie rdzeni, ale także zastosowanie powłoki ochronnej. Grubość powłoki nie ma wpływu na zachowanie rdzeni w czasie deformacji cieplnej.
EN
The influence of coating thickness and sand grains type on sample behavior in high temperature was qualified. As a criterion of estimate of the cores behaviour, the hot distortion test was applied. The received results of investigations show, that the type of sand grains has influence on cores behavior during thermal destruction. The coating thickness has not an effect on changes of cores behavior, during the thermal destruction.
17
Content available remote Technologiczne aspekty regeneracji zużytych mas rdzeniowych utwardzanych CO2
Pezarski F., Izdebska-Szanda I., Maniowski Z., Pasternak M.
Archiwum Odlewnictwa
|
2006
|
R. 6, nr 18/2
423--428
PL
W artykule przedstawiono nowo wdrożony w Kieleckiej Fabryce Pomp „BIAŁOGON” S.A. w Kielcach proces regeneracji piasków ze zużytych mas rdzeniowych ze spoiwem żywicznym utwardzanym CO2. Przedstawiono wyniki badań własności fizykochemicznych materiałów wyjściowych i regeneratu uzyskiwanych na stanowisku regeneracji oraz własności technologiczne mas z zastosowaniem uzyskiwanych regeneratów.
EN
The article describes the process of foundry sand reclamation from the waste CO2 hardened core mixtures with resin binder recently implemented in practical use at the "BIAŁOGON" Kielce Pump Factory S.A. in Kielce. The results of the tests and studies of the physico-chemical properties of base materials and of the reclaim obtained on a reclamation post were presented and compared with the technological properties of sand mixtures made with the reclaimed sand.
18
Content available remote Ocena szybkości wiązania oraz migracji spoiwa w rdzeniach sporządzanych przez wstrzeliwanie masy ze zregenerowaną osnową
Dańko J., Zych J., Dańko R., Jamrozowicz Ł.
Archiwum Odlewnictwa
|
2006
|
R. 6, nr 22
139-144
PL
W artykule przedstawiono badania szybkości utwardzania masy rdzeniowej do technologii cold-box oraz ocenę migracji spoiwa w rdzeniach sporządzanych przez wstrzeliwanie masy, której osnowę stanowiły: świeży piasek, rozdrobniona masa zużyta z technologii cold-box oraz zregenerowana osnowa kwarcowa. Zastosowano regenerację mechaniczną oraz termiczną osnowy, którą ponownie użyto w masach testowych do technologii cold-box. Przeprowadzono badania migracji spoiwa wywołanej przepływem strumieni powietrza wewnątrz porów rdzenia, a także badania wytrzymałości na zginanie masy do technologii cold-box wykonanej na wytypowanych rodzajach osnowy.
EN
The evaluation of hardening intensity of core sand and binder migration in cores prepared by means of shooting core sands based both on fresh, used and on reclaimed cold-box sand base have been presented in the paper. The thermal and mechanical reclamation techniques have been adopted to prepare quartz sand basis used in new cold-box mixtures. The investigation of migration of bonding composition forced by the air stream flow inside core pores were carried out as well as the bending strength of cold-box sand sample with chosen tested sand.
19
Content available remote Badania struktury rozkładu gęstości masy w rdzeniach wykonanych za pomocą wstrzeliwania
Dańko J., Zych J., Dańko R., Sroczyński A.
Archiwum Odlewnictwa
|
2006
|
R. 6, nr 22
133-138
PL
W artykule przedstawiono badania rozkładu gęstości pozornej rdzeni sporządzonych przez nadmuchiwanie i wstrzeliwanie. Zastosowano trzy rodzaje osnowy w masach sporządzonych zgodnie z wymaganiami fenolowego procesu coldbox Ashlanda. Do oceny jakości realizowanego procesu zastosowano badania gęstości pozornej zagęszczonej masy rdzeniowej metodami tradycyjnymi, jak również za pomocą pomiaru prędkości propagacji fali ultradźwiękowej.
EN
The results of core sand density distribution inside the cores manufactured by blowing and shooting techniques have been presented in the article. Three kinds of silica basis were used in testing core sands prepared according to phenolic Ashland cold-box process. The measurement of core sand apparent density obtained inside core volume identified both by the traditional methods as by the ultrasonic valve velocity propagation have been adopted as a validation factors of process quality.
20
Wymywalność szkodliwych substancji z niektórych mas formierskich i rdzeniowych stosowanych w odlewniach żeliwa
Holtzer M., Lewandowski J. L., Bilska M., Grabowska B.
Przegląd Odlewnictwa
|
2004
|
Vol. 54, nr 10-11
870-874
PL
W artykule przedstawiono wyniki badań wpływu na Środowisko mas formierskich i rdzeniowych z żywicą mocznikowo-furfurylową, żywicą furfurylową oraz mas z bentonitem i pyłem węglowym pod względem możliwości wymywania się z nich substancji szkodliwych. Badania prowadzono według własnej opracowanej metodyki przy zastosowaniu specjalnie do tego celu zaprojektowanej i wykonanej formy wraz z rdzeniem sporządzanym każdorazowo z badanej masy. Uzyskane wyniki wyraźnie wykazują, że przepalenie badanych mas ma istotne znaczenie dla rodzaju i ilości substancji wymywających się z tych mas. Wyraźne pogorszenie jakości masy wiązanej bentonitem, pod względem szkodliwości wymywanych z niej substancji, może nastąpić wtedy, gdy będzie w niej domieszka nieprzepalonej masy wyjściowej, na przykład nieprzepalone części rdzeni.
EN
In the article results of the research on the influence of moulding and core sands bonded with the urea-furfuryl and furfuryl resins as well as of the sands with bentonite and carbon dust regarding the possibility of washing out the harmful substances from them were presented. The research was carried out after own method, by employing a special mould projected and made for this purpose with a core made each time of the investigated sand. The received results distinctly shaw that the burning through of the investigated sands is of essential significance for the kind and amount of the substances being washed out from these sands. The distinct quality deterioration of the bentonite sand regarding the harmfullness of the substances being washed from it may occur when it will contain an admixture of the initial sand, e.g. the unburned through core parts.
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