Abstract
Squeezing from the bottom side of a sand mold, which we call under-squeezing, is a more efficient method of compacting sand than other conventional method, such as jolt-squeezing and air impaction. The friction of sand against the walls of the flask impedes the efficiency and precision of sand molds compacted from the upper side with these conventional methods. By contrast, under-squeezing that causes this friction is efficient for compacting sand near the bottom of the flask and pattern faces. We performed experiments on changing the flask height and pattern forms. We clarified the efficiency of compacting sand with molding machines used in factories that are equipped with functions that can change the under-squeezing strokes. The results of the experiments show that under-squeezing compacts molding sand uniformly regardless of the pattern forms and flask height.
