Effect of Sand Wetting on Physically Hardened Moulding Sands Containing a Selected Inorganic Binder. Part 2

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In the paper, an attempt is made to explain the previously observed increased effectiveness of utilising hydrated sodium water-glass grade 137 after hardening moulding sands with selected physical methods. In the modified process of preparing sandmixes, during stirring components, water as a wetting additive was introduced to the sand-binder system. Presented are examination results of influence of faster microwave heating and slower traditional drying of the so-prepared moulding sands on their tensile and bending strength, calculated per weight fraction of the binder. The measurement results were confronted with SEM observations of linking bridges and with chemical analyses of grain surfaces of high-silica base. On the grounds of comprehensive evaluation of hardened moulding sands, positive effects were found of the applied physical process of binder dehydration and presence of the wetting additive. It was observed that introduction of this additive during stirring, before adding the binder, improves flowing the binder to the places where durable linking bridges are created. It was also found that the applied methods of hardening by dehydration enable creation of very durable linking bridges, strongly connected with the sand base, which results in damages of high-silica grain surfaces, when the bridges are destroyed.

[1] Lewandowski, J.L. (1997). Materials for casting moulds. Kraków. Akapit Publishing House (in Polish).

[2] Lewandowski, J.L. (1971). Casting materials. Warszawa Kraków: PWN Publishing House.

[3] Stachowicz, M., Granat, K. & Nowak, D. (2012). Bending strength measurement as a method of binder quality assessment on the example of water-glass containing moulding sands. Archives of Foundry Engineering. 12 (spec. iss. 1), 175-178. (in Polish).

[4] Grabowska, B., Holtzer, M., Dańko, R., Górny, M., Bobrowski, A. & Olejnik, E. (2013). New BioCo binders containing biopolymers for foundry industry. Metalurgija. 52 (1), 47-50.

[5] Grabowska, B. (2009). The cross-linking influence of electromagnetic radiation on water-soluble polyacrylan compositions with biopolymers. Archives of Foundry Engineering. 9 (1). 41–44.

[6] Fuchu, L., Zitian, F., Xinwang, L., Huafang, W. & Jiaqing, H. (2014). Research on humidity resistance of sodium silicate sand hardened by twice microwave heating process. Materials and Manufacturing Processes. 29, 184–187.

[7] Wang, J., Fan, Z., Zan, X. & Pan, D. (2009). Properties of sodium silicate sand hardened by microwave heating. China Foundry. 6 (03), 191-196.

[8] Stachowicz, M., Granat, K. & Pałyga, Ł. (2015). Effect of sand wetting on physically hardened moulding sands containing a selected inorganic binder. Part 1. 56 Scientific Conference „Krzepnięcie i Krystalizacja Metali 2015” Busko Zdrój 02 - 04.09.2015.

[9] Stachowicz, M., Granat, K. & Nowak, D. (2010). Studies on the possibility of more effective use of water glass thanks to application of selected methods of hardening. Archives of Foundry Engineering. 10 (spec. iss. 2), 135-140.

[10] [10] Dobosz, S.M. (2006). Water in moulding and core sands. Kraków. Akapit Publishing House (in Polish).

[11] Hutera, B., Smysky, K. & Drożyński, D. (2007). Influence of lowered temperature on wettability of quartz grains by binders used in moulding sands. Archives of Mechanical Technology and Automation. 27 (1), 47-55.

[12] Jelinek, P. (1996). Prinos ceskoslovenskeho slevarenstvi k chemizacji wyroby forem a jader na bazi alkalickych kremocitanu. Slevarenstvi. 2, 85-103.

[13] Stachowicz, M. & Granat, K. (2014). Possibilities of reclamation microwave-hardened molding sands with water glass. Archives of Metallurgy and Materials. 59 (2), 757-760.

[14] Stachowicz, M. (2015). Possibility of activating used-up inorganic binders on the example of sandmixes containing water-glass hardened by traditional drying. Conference „Foundry engineering. Technology – Practice – Ecology” Karpacz. 25-27.03.2015 (in Polish).

Archives of Foundry Engineering

The Journal of Polish Academy of Sciences

Journal Information

CiteScore 2016: 0.42

SCImago Journal Rank (SJR) 2016: 0.192
Source Normalized Impact per Paper (SNIP) 2016: 0.316


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