MOLDS WITH USE OF INVESTMENT PATTERNS MAKING METHOD Russian patent published in 2007 - IPC B22C9/04 

FIELD: manufacture of shell molds with use of investment patterns.

SUBSTANCE: method comprises steps of applying onto pattern front layer of suspension; slightly drying it; applying further inner layers of suspension; sprinkling said layers and drying them. Front and next layers are applied from suspension with next composition, mass %: aluminum boron phosphate, 16.00 - 20.00; water, 16.00 - 20.00; lignosulfonate (surface active matter), no more than 0.5; magnesium silicate powder, 3.5 - 5.0; pulverized refractory filler, the balance. Front layer is sprinkled with grog having fraction size no more than 0.2 mm; Further layers are sprinkled with grog having fraction size no more than 0.4 mm. Each layer is dried up for 30 - 40 min; pattern composition is melt and mold is subjected to high temperature drying at 300 - 350°C for 2 - 3 hours. Pulverized grog or pulverized synthetic corundum is used as refractory filler for front layer.

EFFECT: increased rate of making mold, improved knocking out capability of mold.

3 cl, 1 tbl, 2 ex