Machine drawn cylinder sheet
Encyclopedia
Machine drawn cylinder sheet was the first mechanical method for "drawing" window glass
. Cylinders of glass 40 feet (12 m) high are drawn vertically from a circular tank. The glass is then annealed
and cut into 7 to 10 foot (2 to 3 m) cylinders. These are cut lengthways, reheated, and flattened.
This process was invented in the USA in 1903. This type of glass was manufactured in the early 20th century (it was manufactured in the UK by Pilkingtons from 1910 to 1933).
Other historical methods for making window glass included broad sheet
, blown plate
, crown glass
, polished plate
and cylinder blown sheet
. These methods of manufacture lasted at least until the end of the 19th century. The early 20th century marks the move away from hand-blown to machine manufactured glass such as rolled plate, flat drawn sheet, single and twin ground polished plate and float glass
.
Glass
Glass is an amorphous solid material. Glasses are typically brittle and optically transparent.The most familiar type of glass, used for centuries in windows and drinking vessels, is soda-lime glass, composed of about 75% silica plus Na2O, CaO, and several minor additives...
. Cylinders of glass 40 feet (12 m) high are drawn vertically from a circular tank. The glass is then annealed
Annealing (glass)
Annealing is a process of slowly cooling glass to relieve internal stresses after it was formed. The process may be carried out in a temperature-controlled kiln known as a Lehr. Glass which has not been annealed is liable to crack or shatter when subjected to a relatively small temperature change...
and cut into 7 to 10 foot (2 to 3 m) cylinders. These are cut lengthways, reheated, and flattened.
This process was invented in the USA in 1903. This type of glass was manufactured in the early 20th century (it was manufactured in the UK by Pilkingtons from 1910 to 1933).
Other historical methods for making window glass included broad sheet
Broad sheet
Broad sheet is a type of hand-blown glass. It is made by blowing molten glass into an elongated balloon shape with a blowpipe. Then, while the glass is still hot, the ends are cut off and the resulting cylinder is split with shears and flattened on an iron plate. . The quality of broad sheet...
, blown plate
Blown plate
Blown plate is one of many types of hand-blown glass. It is made from broad sheet glass by laboriously hand grinding and polishing both surfaces. Blown plate is of a sufficient quality and size for mirrors and coach glasses....
, crown glass
Crown glass (window)
Crown glass was an early type of window glass. In this process, glass was blown into a "crown" or hollow globe. This was then transferred from the blowpipe to a pontil and then flattened by reheating and spinning out the bowl-shaped piece of glass into a flat disk by centrifugal force, up to 5 or...
, polished plate
Polished plate
Polished plate is a type of hand-blown glass. It is produced by casting glass onto a table and then subsequently grinding and polishing the glass. This was originally done by hand, and then later by machine...
and cylinder blown sheet
Cylinder blown sheet
Cylinder blown sheet is a type of hand-blown window glass. It is created with a similar process to broad sheet, but larger cylinders are produced by swinging the cylinder in a trench. The glass is then allowed to cool before the cylinder is cut. The glass is then re-heated and flattened...
. These methods of manufacture lasted at least until the end of the 19th century. The early 20th century marks the move away from hand-blown to machine manufactured glass such as rolled plate, flat drawn sheet, single and twin ground polished plate and float glass
Float glass
Float glass is a sheet of glass made by floating molten glass on a bed of molten metal, typically tin, although lead and various low melting point alloys were used in the past. This method gives the sheet uniform thickness and very flat surfaces. Modern windows are made from float glass...
.