Manufacturing Process of Neon Signs
For those who may not be familiar, a neon sign may be simplistically described as a
lighting display made of neon gas-filled glass tubes bent into the shape of letters or
fascinating designs for decorative purposes. When heavy voltage electrical current is
passed through the captured gas, the tubes emit light and the illumination lures all
onlookers and passers by.
With the advancement of technology, today many
other gases other than neon gas are used in the
manufacture of neon signs. As a matter of fact,
the most commonly used gas nowadays is Argon, or
an argon-neon mixture. Pure neon gas are seldom
used “although the nomenclature neon signs remain.
To enhance the intensity of the light, some
manufacturers add a small amount of mercury to the
argon to produce a powerful blue light.
To offer a wide array of bright and sparkling colors,
manufacturers coat the glass tubes with a variety of tints and phosphor. Optical tints
in various colors are also used and the glass at times is left clear without any tint, to
create a strong blue light. Manufacturers also use xenon, krypton, and helium gases
for bringing out special color effects.
Neon signs have very wide range of applications a
small advertisement to huge complicated designs as
many businesses have begun to realize cost-
effectiveness of neon sings as advertisement
material.
It may be worthwhile to know that the glass tubing
used in making neon signs is soft lead glass which
is capable of being bent to shape. This glass is
generally available in lengths of four to five feet and
with varying diameter all below one inch.
Further, the electrodes in each end of the illuminated tubing are made from virgin
iron surrounded by a cylindrical glass jacket having one end open. A wire is then
attached to the metal electrode and passed through the closed end of the glass
envelope. The closed end is sealed into the end of the sign tubing with the open end
protrusion inserted into the tube.
The high-voltage electricity required is obtained by a transformer which you will be
surprised to know - converts 120 volts from the electrical lines to as high as 15,000
volts needed for the sign. The transformers, it must be noted, are connected to the
electrodes in the sign by means of a special wire, known as GTO wire. This wire is
also used to connect the individual sections of illuminated tubing in series. For safety
purposes, the wire is connected to the transformer through an insulated housing
made of a type of glass called borosilicate glass.
Though a mechanical process, manufacturing neon sign is a pleasant work
experience. There is lot of scope for imagination and creativity as each sign is
unique and must be designed bearing in mind the purpose why it is being installed

and the available space for installation. The diameter of the tube, the minimum
radius the tubing can be bent, and the overall length of tubing the transformer are
all the other parameters that can influence and restrict the design.
The exact step-by-step process of manufacturing Neon Signs is as follows:
• Lengths of glass tubing are cleaned and placed vertically in a coating machine
which penetrates liquid phosphor suspension into the tube for eventual
draining. The tubes are exposed to heat for the coating to dry. Color tints are
applied in a similar manner.
• The glass tubing is gently heated and softened using a variety of burners to
facilitate bending. Using the asbestos template as a guide, the tubing is bent
by hand.
• Thereafter a process known as bombarding is used to remove any impurities
from the glass, phosphors, and electrodes.
• Once the tube has cooled, the gas is inserted under low pressure. The
tabulated port is then heated and sealed off.
• The finished gas-filled tubing is put through an aging process to allow the gas
in the tube to stabilize and operate properly. A transformer, often rated
slightly higher than the normal operating current, is attached to the
electrodes.
• Small neon signs are mounted on their framework and wired in the shop.
Larger signs may be mounted in pieces and put into place on the building or
other support structure where they are interconnected and wired.
Source:
http://www.myneonhaven.com/Neon/2009/05/manufacturing-process-of-
neon-signs.html