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1
Content available remote Ecological aspects of the use of lost foam patterns
Żółkiewicz Z., Maniowski Z., Sierant Z., Młynski M.
Archives of Foundry Engineering
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2010
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Vol. 10, iss. 3
159--162
EN
The paper discusses some aspects of ecology in the use of lost foam patterns for piece production of large castings poured from ferrous alloys under the conditions of Metalodlew SA. Foundry. The technological processes used in the manufacture of castings are related with numerous hazards. Numerous problems requiring prompt solution occur also during the process of foundry mould pouring, to mention only various contaminants, air pollution, noise and other factors harmful to the human health and natural environment. Various technological processes cause strenuous work conditions in foundry shops. Many of the publications that have appeared so far dealing with the problems of environmental protection and hard work conditions in foundries [1, 2, 3, 4, 5, 6, 7, 8, 9] discuss in both general and detailed way problems related with various pollutants, noise and other factors harmful to the human health and natural environment, responsible for hazards faced by foundry workers. Studies carried out by various R&D centres are mainly focussed on the problem of how to reduce the harmful effect of technological processes on the environment through modification of the already existing or development of new ecological and energy-saving materials and technologies. This paper shows the opportunities and threats resulting from the application of the Lost Foam Process in a foundry, which up to now has been using a more traditional technology.
2
Content available remote Characteristic properties of materials for evaporative patterns
Żółkiewicz Z., Żółkiewicz M.
Archives of Foundry Engineering
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2010
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Vol. 10, iss. 3 spec.
289--292
EN
To complete the cast models including EPS process the use of different materials such as polystyrene, copolymer, others. One of the main parameters affecting the flow of metal in the mold of the gasification kinetics model. In studies described in this article, attention has been focussed on the determination of gas volume emitted from evaporative patterns of predetermined density. Two variables were used, i.e. the type of material for evaporative patterns and temperature. The effect of pattern evaporation temperature on the emitted gas volume was investigated. Tests were carried out on samples representing various materials. In this part of the article, the gas evolution rate at temperatures of up to 400oC was discussed. The obtained results were depicted in graphical form.
3
Content available remote Modeling of mould cavity filling process with cast iron in Lost Foam method Part 3. Mathematical model – pressure inside the gas gap
Pacyniak T., Kaczorowski R.
Archives of Foundry Engineering
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2008
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Vol. 8, iss. 3s
79--83
EN
In this work mathematical model describing changes of pressure inside the gas gap was shown during manufacturing gray cast iron castings with use of lost foam process. Authors analyzed the results of numerical simulation enclosing influence of foamed polystyrene pattern density, permeability and thickness of refractory coating on pressure changes in the gap. Studies have shown, that all these parameters have significant influence on pressure inside the gas gap.
4
Content available remote Modeling of mould cavity filling process with cast iron in Lost Foam method Part 1. Mathematical model – rate of pattern gasification
Pacyniak T., Kaczorowski R.
Archives of Foundry Engineering
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2008
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Vol. 8, iss. 3s
69--74
EN
In this work a mathematical model of mould cavity filling process with cast iron for lost foam method was shown, enclosing phenomena connected with gasification of foamed polystyrene pattern. For its description the thermal balance equation was used, which together with pouring rate equations (part 2) and pressure change equations (part 3) enabled determination of permeability, refractory coating thickness and foam pattern density influence on pouring rate, gas pressure in gas gap and its size. In this work authors showed results of numerical simulation concerning rate of pattern gasification and gas gap size, based on developed mathematical model. Presented studies indicated, that with decrease in coating permeability and increase in its thickness the gas gap size increased causing the decrease of foamed polystyrene pattern gasification rate.
5
Content available remote Modeling of mould cavity filling process with cast iron in Lost Foam method Part 2. Mathematical model – Pouring rate
Pacyniak T., Kaczorowski R.
Archives of Foundry Engineering
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2008
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Vol. 8, iss. 3s
75--78
EN
In this work pouring rate equation for cast iron in lost foam process was shown. For description of this phenomenon the motion dynamic equation was used. Pressure affecting the liquid cast iron surface was described using Bernoulli formulae. Numerical simulation results were analyzed with respect to permeability, refractory coating thickness and foamed polystyrene pattern density influence on pouring rate.
6
Ocena właściwości powłok ceramicznych stosowanych na modele z polistyrenu spienionego w metodzie pełnej formy
Jankowski W., Wojtaszek A.
Przegląd Odlewnictwa
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2000
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Vol. 50, z. 7-8
269-270
PL
W metodzie pełnej formy pokrycie modelu z polistyrenu spienionego ceramiczną powłoką ogniotrwałą odgrywa kluczową rolę i decyduje o jakości uzyskiwanych odlewów. Od powłoki wymaga się z jednej strony odpowiedniej wytrzymałości, z drugiej - odpowiedniej przepuszczalności produktów gazowych, powstających w wyniku destrukcji cieplnej modelu. W referacie podjęto próbę określenia kryteriów oceny przydatności tych powłok. Skonstruowano i wykonano przyrząd, umożliwiający współpracę z aparatem do oznaczania przepuszczalności mas formierskich. Aby umożliwić porównywanie wytrzymałości badanych, różnych powłok, opracowano odpowiednie wskaźniki: WR i WRJ. Do badań zastosowano kilkanaście rodzajów powłok ceramicznych. Przeprowadzone badania wykazały pełną przydatność metody i aparatu do badania wytrzymałości i przepuszczalności warstw ceramicznych powłok ogniotrwałych, stosowanych na modele z polistyrenu spienionego w technologii formy pełnej. Z badań wynika, że zwiększenie liczby warstw powłoki nie wpływa w znacznym stopniu na jej wytrzymałość, a jednocześnie powoduje zauważalne obniżenie przepuszczalności danej powłoki.
EN
In the full mould technology covering a foamed polystyrene patttern with a ceramic refractory coating plays an important part and decides on the quality of the produced castings. From one hand the coating requires appropriate strength, and from the other one good permeability of gaseous products which are formed as a result of thermal destruction of a pattern. In the article an attempt has been undertaken to determine the assessment criteria of usefulness of these coatings. A device, which makes the co-operation with the apparatus for determination of moulding sands permeability possible, has been designed and made. The suitable indicies WR and WR1 have been elaborated to make the comparison of the strength of various tested coatings possible. Several kinds of ceramic coatings have been used in testing. The carried out tests have indicated the full usefulness of the method and apparatus for testing both the strength and permeability of the layers of ceramic refractory coatings used for foamed polyst rene patterns in the full mould technology.
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