Modelling the effects of the pressure changes in the case of the growth of a thin sheet in an edge-defined film-fed growth (EFG) System

In this paper it is shown that due to the pressure p in the furnace there are three limitations αc_, αc¯, αc¯¯ for the contact angle αc. The lower limit αc_ is in the range (0,π/2-αe), depends on p and on the half-thickness w of the die. The upper limit αc¯ is in the range ( π/2-αe,π/2) and increases when p increases. The limit αc¯¯ is in the range (π/2-αe,αc¯) and depends on p and w. It is shown also, that there exist two limitations w1(p) and w2(p) for w. If w is in the range (0, w1(p)), then the growth angle is achieved for the contact angle in the range (π/2-αe,αc¯¯), and if w∈(w1(p),w2(p)) the growth angle is achieved for the contact angle in the range (π/2-αe,αc¯). The menisci are concave. If w>w2(p), then the growth angle is achieved for the contact angle in the range (αc_,αc¯) and the meniscus is convex-concave. Numerical examples are given for thin silicon sheets of half-thickness 0.5(cm×10-2).