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Properties of moulding mixtures of mixed bentonites after repeated use
Virgl, Vítězslav ; Neudert, Alois (referee) ; Kaňa, Václav (advisor)
High class mold is required for high quality castings. At present, the demands on molding materials are being extended by adding the strict requirement of environmentalists. A suitable variant that meets both demands are green sand molds. The goal of the thesis is to repeatedly cast experimental castings into molds made of 4 types of green sand mixtures. The technological properties of the molds will be compared, the degree of bentonite degradation will be assessed and the surface quality of castings will be assessed according to the amount of adherent molding mixture.
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Penetration of metal into green sand during pouring of iron castings
Ptáček, Tomáš ; Neudert, Alois (referee) ; Záděra, Antonín (advisor)
This diploma thesis deals with the creation of penetration of cast iron with graphite casting cast into bentonite molds. In the first part of the thesis is theoretically described the formation of penetration, its main causes, consequences and the elimination of this defect. The second part analyzes the causes of the defect with the Minitab statistical software and shows the possible connections of the input materials to the occurrence of the defect. Next, the experimental finding of the cause of the defect, which is focused on the measurement of the pressures in the form of the casting, is devoted to it.
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Comparison environmental and technological properties of various technologies of productions of foundry moulds and cores
Walek, Josef ; Neudert, Alois (referee) ; Cupák, Petr (advisor)
This bachelor thesis deals about comparison of environmental and technological properties of various technologies of productions of foundry moulds and cores. The thesis comprises overview of technologies of produciton of foundry moulds and cores used in foundry practice and the individual technologies are described properties, advantages, disadvantages and applications. There are mentioned harmful substances which are contained in the binder systems or are formed during casting. Requirements for ecological production castings are becoming stricter, therefore a prerequisite for the development of new methods which are environmentally friendly and are also characterized by advantageous technological and economical characteristics.
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Test the applicability of biogenic binders during casting of gray cast iron
Fiala, Vlastimil ; Neudert, Alois (referee) ; Cupák, Petr (advisor)
The thesis deals with verification of applicability of biogenic binders during casting of gray cast iron. Applicability of these binders for making moulds as well as cores was verificated. The introduction describes strength of cured mixture with biogenic binder including influence of additives and refractory coating. The main part describes process of manufacturing of castings being poured into the biogenic binder bonded moulds. Pouring castings with cores bonded with the same binder is described as well. The last part deals with assessment of the given tests. The thesis comprises photodocumentation of poured samples.
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STUDY OF BIOGENOUS BINDERS
Cupák, Petr ; Jelínek, Petr (referee) ; Neudert, Alois (referee) ; Rusín, Karel (advisor)
oundry production, which forms an integral part of the engineering industry, is a source of waste with a negative impact on the working and living environment. The pressure on greening the production in all production branches of industry does not dodge the foundry industry and technical engineers seek out possibilities of decreasing the negative impact of the production of casting on the environment. An important source of environmentally dangerous waste in foundry operation is the use of organic compounds during the preparation of shaping and core mixtures. Their substitution with materials that would ensure similar technological features of the shaping and core mixtures as the organic materials used hitherto and at the same time decrease the amount of solid, liquid and gaseous ecologically undesirable compounds used in or arising during the preparation and use of shaping and core mixtures, would be significant for decreasing the ecological burden connected to casting production. A promising group of materials usable as components of shaping and core mixtures are the biopolymer materials which can substitute the organic connective systems used in the production of foundry cores by the means of the so-called hot processes – Hot-Box and Warm-Box. This work focuses on the exploration of the technological and ecological features of several biopolymer materials available on the domestic market which have the potential to become a full alternative of the binders used so far on the basis of urea-formaldehyde, melamine-formaldehyde, phenol-formaldehyde and furan resins.
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OPTIMIZATION OF TECHNOLOGICAL PROPERTIES OF CEMENT SAND MIXTURES
Burianová, Klára ; Nová, Iva (referee) ; Neudert, Alois (referee) ; Rusín, Karel (advisor)
The work deals with optimization of the technological properties of cement-sand mixtures. The main objective is to find the correct mixture of the individual components which contribute to the rapid solidification of the mixture, hence shorter dismantling. The content is also of a method of measuring and recording during the plasticity of the mixture. Also assessment of the velocity of hydration heat cement mixture in the initial stage of the solidification process in the course of the strength properties of the mixture. To assess these phenomena was used calorimetric method used for measuring hydration heat cement mixture. Further measurements plasticity mixtures and mechanical and physical methods for measuring the compressive strength with the help of a measuring instrument LRU-D.
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Properties of moulding mixtures of mixed bentonites after repeated use
Virgl, Vítězslav ; Neudert, Alois (referee) ; Kaňa, Václav (advisor)
High class mold is required for high quality castings. At present, the demands on molding materials are being extended by adding the strict requirement of environmentalists. A suitable variant that meets both demands are green sand molds. The goal of the thesis is to repeatedly cast experimental castings into molds made of 4 types of green sand mixtures. The technological properties of the molds will be compared, the degree of bentonite degradation will be assessed and the surface quality of castings will be assessed according to the amount of adherent molding mixture.
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Penetration of metal into green sand during pouring of iron castings
Ptáček, Tomáš ; Neudert, Alois (referee) ; Záděra, Antonín (advisor)
This diploma thesis deals with the creation of penetration of cast iron with graphite casting cast into bentonite molds. In the first part of the thesis is theoretically described the formation of penetration, its main causes, consequences and the elimination of this defect. The second part analyzes the causes of the defect with the Minitab statistical software and shows the possible connections of the input materials to the occurrence of the defect. Next, the experimental finding of the cause of the defect, which is focused on the measurement of the pressures in the form of the casting, is devoted to it.
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