PREPARATIONOF HIGH POROSITY SLUMPING MOLD FROM REFRACTORY MORTAR

Nithiwach  Nawaukkaratharnant; Bordin  Wiratphinthu; Siriphan  Nilpairach; Thanakorn  Wasanapiarnpong

Authors

Nithiwach Nawaukkaratharnant Research Unit of Advanced Ceramics, Department of Materials Science, Faculty of Science, Chulalongkorn University, Phathumwan, Bangkok, 10330, Thailand.
Bordin Wiratphinthu Italian-Thai Ceramic Refractory Co, Ltd. Thaluang, Tharuea, Autthaya, 13130, Thailand.
Siriphan Nilpairach Metallurgy and Materials Science Research Institute, Chulalongkorn University, Bangkok, 10330, Thailand.
Thanakorn Wasanapiarnpong Research Unit of Advanced Ceramics, Department of Materials Science, Faculty of Science, Chulalongkorn University, Phathumwan, Bangkok, 10330, Thailand.

Keywords:

Slumping mold, refractory mortar, dolomite clay, alumina, porous

Abstract

Sagging molds or slumping molds are used for putting glass plate onto a third dimension and areused for the production of glassware containers and many kinds of sagging glass articles. The use of slumping molds has been favored by many sagging glass factories in Thailand. However, such molds must be imported athigh cost from abroad. Refractory mortar is a candidate material for making slumping molds due to the easeoffabricationin every shape and size. In this study, dolomite clay, calcinedalumina, and white Portland cement were mixed with distilled water 40 wt% into apaste. The flow ability of the paste was adjusted by the addition of a super plasticizer. The paste waspoured intoplastic containersused as molds and cured at room temperature for 48 h. After being dried in air for 24 h, specimens were dried in an oven at 110oC for 24 h and then were fired at1000-1250oC in an electrical box furnace. The results show that the proper ratio of raw materials is dolomite clay 40 wt%, calcinedalumina 35 wt%, white portland cement 25 wt%, and water 40 wt%. High porosity specimens with suitable density are achieved when fired at 1250oC. The effects of the firing of the samples on theirchemical property, thermal property, and microstructure will be discussed.

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