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Base sands for manufacture of foundry moulds and cores
Sedláčková, Petra ; Rusín, Karel (referee) ; Cupák, Petr (advisor)
This bachelor thesis describes a summary of sands which are used for foundry molding materials, and includes fields of their utilization. Surface structures of grains as well as their typical chemical and physical parameters are introduced. Czech quartz sands Provodín and Střeleč are described, further also the Slovak sand Šajdíkove Humence, Polish sands Szczakowa a Grudzeń Las, German sands Frechen and Haltern, and the American sand GBM. Out of non-quartz sands, there are listed: chamotte, Molochit, LK Sand from the Sand Team company, ceramic sands CKL and CKI from the Giba company, olivine, dunit (Magnolit), zircon, chromite, magnesite and chrom-magnesite, salt (salt cores). In the summary, there are also listed special sands of the German Hüttenes-Albertus company which are described in detail in Appendix 1. Sands are compared in graphs and tables according to these requirements: thermal expansion, a grain shape and medium grain size, a volume of elutriated parts smaller than 0.9 mm, refractoriness and a point of sintering.
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Influence of type of base sand on strength of geopolymer sand mixture
Kudr, Martin ; Šupálek, Milan (referee) ; Cupák, Petr (advisor)
The goal of this research is to find out the effect of different types of opening material on bending strength geopolymer’s moulding mixture. Four different silical opening material were used along with two types of binder. To solve the selected problem I have used the test of bending strength. At first I have prepared the moulding mixture and after its induration, I have tested the bending strength. The times were always the same 60, 120 and 1440 minutes. The highest level of bending strength was achieved at opening material SH-34 when using binder Geopol 618. The value of bending strength level was 0,881MPa. The results of this research could help the foundries during implementing technology of geopolymer moulding mixture, which would help particulary when looking for a proper opening material.
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Water soluble foundry binders with heat hardening
Vaverka, Jiří ; Rusín, Karel (referee) ; Cupák, Petr (advisor)
This thesis is focused on water soluble foundry binders with heat hardening. The thesis comprises general description of moulding mixtures, the description of the most common methods used for heat hardening and primarily the list of current and alternative binders, which reduce negative environmental impact of foundries. Also their qualities, benefits and drawbacks are included.
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Water soluble foundry binders with heat hardening
Dratnal, Lukáš ; Rusín, Karel (referee) ; Cupák, Petr (advisor)
With the increasing foundry requirements we are forced to develop new kinds of foundry binders, either organic or inorganic. There are several requirements for the molding composition and for the proper function. The sand mixture must exhibit appropriate technological, economic and also ecological characteristics. Many environmentally harmful wastes are created from the organic substances contained mainly in binders and catalysts used for molding of the mixture. A good application can be the water-soluble binder cured by heat. These binders allow easy and fast processing and a mixture recoverability.
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Comparison of technological, environmental and economical properties of various binder systems of mould sand mixtures
Ambrož, Ondřej ; Rusín, Karel (referee) ; Cupák, Petr (advisor)
This bachelor thesis is focused on a comparison of technological, environmental and economical properties of various binder systems of mould sand mixtures. The thesis comprises basic overview of the systems used in foundry practice and the individual systems are described properties, advantages, disadvantages and applications. There are mentioned harmful substances which are generated during the preparation of the sand mixture and during casting. Requirements for ecological production castings are a prerequisite for the development of new methods which are environmentally friendly and are also characterized by favorable technological and economic characteristics.
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Water soluble foundry binders with heat dehydratation hardening
Šebesta, Pavel ; Rusín, Karel (referee) ; Cupák, Petr (advisor)
Environmental pressure on foundries has forced manufacturers to develop new organic and inorganic binders. One of the options is water soluble binders that can be hardened by dehydration. In addition to tenacity characteristics and regenerability of the forming mixtures another considered aspect is the amount of emissions generated by casting. Use of these new binders does not require expensive modifications of the machines for work with the forming mixtures.
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Manufacture of centrifugal Castings
Minář, Martin ; Rusín, Karel (referee) ; Cupák, Petr (advisor)
The main goal of this bachelor thesis is to collect basic information related to the production of castings by centrifugal casting. It is focused on horizontal and vertical centrigugal casting, casting of various metals and their alloys, such as zinc, aluminum, iron, steel and silumin. This technology is compared with other casting methods in terms of specific characteristics, amount of usage, production economics, advantages, disadvantages, the resulting quality of castings and other factors.
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