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Glass History 

1933

 PPG's Pennvernon Window Glass
 A Brief Look At the Manufacturing Process

 

The Pennvernon
Drawing Machine
 

    The Pennvernon Drawing Machine is a production line in one unit. A set of precision rolls support the glass vertically and draws upward and processes the film of glass which has been introduced by a bait. The bait removed, and the rolls keep the glass rolling upward to be cut to size.
    Commercial production of flat-drawn sheet window glass by the Pennvernon process was started at Works No. 11 at Mt. Vernon Ohio in 1925 and in 1927 the process was put into operation at Works No. 12 at Clarksburg, West Virginia.

    The superior quality flat drawn sheet glass marketed by the PPG company under the name Pennvernon is produced in it's finished from by drawing vertically from a free, open bath of molten glass as a continuous flat sheet.

In the Pennvernon drawing process the following procedures are unique:

  • The sheet is drawn from a free, open bath with no possibility of contamination from clay or other refractory surfaces.
  • The drawn sheet is not contacted on either side until the surfaces are set beyond danger of being marked.
  • Improved means of temperature control during the sheet forming process have produced a sheet of unmatched flatness and freedom from visual distortion.
    Different thicknesses of sheet are produced by varying the speed of draw - the slower the speed the heavier the sheet, and vice versa; faster drawing produces thinner sheets.

    As the sheet progresses upward it cools and, at the top of the machine, is ready to be severed into sheets of the desired size.

Information from PPG 1946