Effect of Mold Material on Shrinkage of Investment Casting Wax Pattern
Abstract
Various attempts have been made to substitute metal as the wax pattern mold material due to manufacturing costs and time-consumption. This research investigates the linear and volume shrinkage on the wax pattern of gypsum, silicone rubber, and epoxy resin as alternative materials to metal molds. A nylon master pattern was made by machining. The master pattern size was set as a reference for dimensional comparison with the cast wax pattern. Wax pattern molds were created using the master pattern, namely gypsum, silicone rubber, and epoxy resin. Paraffin wax was heated up to 55ËšC in metal, then poured into each wax pattern mold. The length, radius, inlet, and outlet diameter were measured using a profile projector, then the linear shrinkage was calculated. The volume shrinkage was obtained through the sample weighing. The results show that silicone rubber has the lowest linear shrinkage of any sample in contrast to its volume shrinkage.
References
[2] Hafid. (2012). Penelitian bahan substitusi import untuk pembuatan cetakan keramik pada teknologi proses investment casting, in: Proseding Pertem. Ilmu Pengetahuan dan Teknologi Bahan, Serpong: 105-111.
[3] Sandhu, E.C.S. & Sharma, E.A. (2012). Investigation of optimize wax pattern in the investment casting by using the different form of waxes, IOSR Journal Mechanical Civil Engineering, 3, 2278-1684.
[4] Alparabbi, R., Duskiardi & Budiman, H. (2013). Pengecoran aluminium bekas menggunakan cetakan gypsum dengan pola lilin, Jurnal Teknik Mesin, F.T. Industri, U.B. Hatta, 2(2), 1-9.
[5] Murdiya, F. (2017). Investigation of Mixture of Epoxy Resin/Palm Kernel Shell as Insulation, Journal Of Ocean, Mechanical And Aerospace -Science And Engineering-, 43(1), 1-6.
[6] Phetrattanarangsi, T., Puncreobutr, C., Khamkongkaeo, A., Thongchai, C., Sakkomolsri, B., Kuimalee, S., Kidkhunthod, P., Chanlek, N. & Lohwongwatana, B. (2017). The behavior of gypsum-bonded investment in the gold jewelry casting process, Thermochimica Acta, 657, 144-150.
[7] Sulistiyono, B. & Mudaryoto, J. (2019). Pembuatan sudu shot blast dengan metode pengecoran presisi (investment casting) menggunakan epoxy resin sebagai pola, Tesis Master, Program Studi Teknik Metal, Manufaktur Program Pascasarjana Bidang Ilmu Teknik. UI. 602.
[8] Guler, K.A. & Cigdem, M. (2012). Casting quality of gypsum bonded block investment casting moulds, Advanced Material Research, 445, 349-354.
[9] Kusyairi, I., Choiron, M.A., Himawan, H.M. & Irawan, Y.S. (2020). Differences in precision of wax molds made of portland cement and silicone rubber in investment casting process for economic efficacy, IOP Conference Series Material Science Enggineering, 845.
[10] Yaman, K. & Taga, Ö. (2018). Thermal and electrical conductivity of unsaturated polyester resin filled with copper filler composites, International Journal of Polymer Science, 1-10.
[11] Shin Etsu Company. (2016). Characteristic properties of Silicone Rubber Compounds Meeting the increasingly diverse and sophisticated needs of industry with the unique properties of silicone rubbers.
[12] Surdia, T. & Chijiiwa, K. (1982). Teknik Pengecoran Logam. Pradnya Paramita, Jakarta.
[13] Cengel, Y.A. (2015). Thermodynamics: An Engineering Approach Introduction and Basic Concepts. The McGraw-Hill Companies.
[14] Velarde, M.G. (1998) Drops, liquid layers and the Marangoni effect, Philosophical Transactions of the Royal Society A, Math. Phys. Eng. Sci., 356, 829-844.
[15] Wahyudi, U. (2015). Pengaruh injection time dan backpressure terhadap cacat penyusutan pada produk kemasan toples dengan injection molding menggunakan material polistyrene, Jurnal Teknik Mesin, 4, 81-89.
[16] ASM International. (1998). ASM Handbook Vol. 15 Casting, 9th ed., ASM International.












