Step 1: Requirement of Window Glass Manufacturing:
Window glass must have uniform thickness, high transparency, and perfectly flat and parallel surfaces. Producing such geometry requires a specialized continuous manufacturing process.
Step 2: Float-Bath (Float Glass) Method:
In the float-bath method, molten glass is poured onto a bath of molten tin. Since molten glass is less dense than tin and both are immiscible, the glass floats on the tin surface. Surface tension and gravity naturally spread the glass into a flat sheet of uniform thickness.
Step 3: Rejection of Other Options:
Investment casting is used for metals, patenting is a heat treatment process for steel wires, and spray forming is used for metallic preforms. None of these processes are suitable for flat glass production.
Final Conclusion:
Therefore, the float-bath method is the standard industrial process used for manufacturing window glass.