Influence of conditions of preparing the foamed plaster on its degree of foaming

• Autorzy: Pawlak, M.
• Języki publikacji: EN

Abstrakty

EN

Foamed plaster moulds are used in precision casting process of non-ferrous alloys. Casting from those moulds are characterizedby high dimensional accuracy, very good shape pattering and small surface roughness. However, a drawback of the plaster mould is very low permeability. A substational improvement of this parametr may be achived through physical or phisico-chemical treatment of the plaster slurry or prepared mould. The most advantageous results can be obtained by foaming the slurry. The investigatious comprised evaluation of the influence of mixing parametrs (mixer type, rotation and mixing time, settings the mixer in mixing device) and the content of a foaming agent on the degree of foaming of the plaster. The tests were carried out using the [alpha]-plaster Hartform-H1 and Alkanol XC as a foaming agent. The structure of a slurry produced after foaming is non-homogeous. Therefore, the investigations were completed by making appropriate of this process. Analysis of the results leads to the conclusion, that the foamed plaster Hartform-H1 reaches the top degree of foaming at the following parameters: the water/plaster ratio W/G=0.55, the content of Alkanol XC a=0.07%, stirring with a perforate disc mixer at the rotation speed nm=4000 rpm during ôm=30 s. In turn the top homogeneity of the foamed plaster slurry can be achieved at the rotation speed nu=1400 rpm during ôu=30 s., while other parameters are the same as in the foaming process. The obtained results can provide the basis for the elaboration of the industry procedures useful in the production of the plaster moulds for precision casting.

Słowa kluczowe

PL

materiały innowacyjne w odlewnictwie; technologie innowacyjne w odlewnictwie; odlewnictwo precyzyjne

EN

innovative foundry materials; innovative foundry technologies; foamed plaster mould; foamed plaster process; precision casting

• Czasopismo: Archives of Foundry Engineering
• Rocznik: 2007
• Tom: Vol. 7, iss. 3
• Strony: 105-110
• Opis fizyczny: Bibliogr. 6 poz., fot., wykr.

Twórcy

autor

Pawlak, M.

• Technical University of Lodz, Department of Materials Engineering and Production Systems, Stefanowskiego Str. 1/15, 90-924 Łódź, Poland,

Bibliografia

• [1] Lewandowski L.: Moulding materials (Materiały na formy odlewnicze), Akapit, Warsaw 1997.
• [2] Nelson C. D.: Plaster Molding, Metal Handbook, Vol. 15, Casting, p. 242÷247 (1998).
• [3] Clegg A. J.: Precision Casting Processes, Pergamon Press 1991.
• [4] Wiktorski M., Pawlak M., Niedźwiedzki Z.: A stand to search coefficient of thermal conductivity for materials applied on plaster moulds in precision casting (Stanowisko do badania wspólczynnika przewodzenia ciepła materiałów stosowanych wna formy gipsowe w odlewnictwie precyzyjnym), Archives of Foundry, PAN 2004, np. 13, p. 232÷240.
• [5] Koch R., Noworyta A.: Mechanical processes in chemical engineering (Procesy mechaniczne w inżynierii chemicznej), WNT, Warsaw 1995.
• [6] Zajder R.: Influence of parameters of preparing the foamed plaster on its degree of foaming (Wpływ parametrów sporządzania masy formierskiej z gipsu pianowego na jej stopień spienienia), M.A thesis under M. Pawlak's guidance, Łódź 2005.