Rupture phenomena of molten alkali silicate thin films

The rupture length of the iron bearing alkali silicate thin films (the K2O . 2SiO(2), K2O . 2SiO(2) and Na2O . 2SiO(2)-Fe2O3 systems) are measured as a function of the silica content, the Fe2O3 content, temperature, and the drawn out rate. In these melts, it is found that the rupture length, L, depends on the drawn-out rate, v, at the high drawn-out rate conditions, but is independent from the drawn-out rate at the low drawn-out conditions. For all the systems of K2O-SiO2 and Na2O-SiO2-Fe2O3, the rupture length (L) at the high drawn out rate conditions is found to be proportional to the -2/3 of the power of the drawn-out rare (v), L infinity>(*) over bar * (v)(-2/3) The rupture length at the low drawn-out rate strongly depends on the SiO2 and Fe2O3 contents, but not temperature and drawn-out rate. From these results, it is confirmed that the rupture length at the low drawn-out rare is determined by the Si-O bond strength of the silicate tetrahedral units.