Sheet glass

Question 1

How was window glass made until the 16th century?

Answer 1

~ by blowing large cylinders that were cut open, falttened, and cut into panels (panes)

~ resulting windows were divided into transoms, holding the rectangular panels in place

Question 2

How is sheet glass made from the early 1920’s?

Answer 2

~ a continuous ribbon of plate glass was cast on iron paltes, which was then passed through a series of in-line grinders and polishers to form non-distorting plate glass

~ expensive process

Question 2

How is sheet glass made from the early 1920’s?

Answer 2

~ a continuous ribbon of plate glass was cast on iron paltes, which was then passed through a series of in-line grinders and polishers to form non-distorting plate glass

~ expensive process

Question 3

What is the Fourcault process?

Answer 3

~ developed in early 1900s

~ a thin sheet is drawn upwards from a pool of molten glass

~ a DEBITEUSE, a ceramic die, sinks from the melt surface to a prescribed depth, which pushes a part of the molten glass slightly above its interior top surface

~ out of the debiteuse extrudes a ribbon of glass of rectangular cross section

~ the base of the drawn glass ribbon is shielded from heat radiation from the melt, so it holds its shape

~ the sheet is gripped by long rolls that apply the drawing effort and extend nearly to the edges

~ the glass is drawn vertically to 20ft, extending through an annealing lehr, as it cools, the rising ribbon is cut into 4-5 feet lengths

~ surfaces by this process aren’t as smooth or uniform as the later-developed float process