Abstract
Researches were directed towards to analysis if “Tobiko” mainly consist of glucomannan has the suitable properties for mold sand binders by testing both in laboratory and foundry.
With a view to know these properties, following tests were carried out ; compression test, permeability test, moisture absorption test and collapse test in laboratory, and also casting test in foundry.
These tests have given us the results that tobiko has the better properties in laboratory but the worse in foundry. According to these tests, while tobiko has a good binding power in baking at lower temperature, when heated above 400'C the binding power disappears at pouring of molten metals.
Therefore, in the case of molten metal cast in the mold using tobiko as a mold sand binder, bad surface of castings are due to this phenomenon.
From these results, it is obvious that using tobiko as a binder of mold sand is not desirable for practice in foundries. If, however, tobiko is used with other proper mold sand binders, it may be interesting to use tobiko as a binder of mold sand in foundries. (N. T.)
