Neon Lighting Display Made of Glass Tubes

Neon Lighting Display Made of Glass Tubes: A Neon sign is a Lighting Display made of glass Tubes that have been filled with a Gas and bent into the shape of letters or decorative deSigns. When a high-voltage Electrical current is passed through the Gas, the Tubes emit Light. Although Neon Gas was originally used in these Signs, several other Gases are also used.

Raw Materials: Although Neon Gas was originally used in Neon Signs, it is now only used to produce reds and oranges. Argon, or an Argon-Neon mixture, is used in most Signs. To improve the intensity of the Light, a small amount of mercury is added to the Argon to produce an intense blue Light.

Illuminated Tubing: The Electrodes in each end of a section of illuminated tubing are usually made from very pure iron surrounded by a cylindrical glass jacket or envelope with one end open. A wire is attached to the metal electrode and passes through the closed end of the glass envelope. The closed end is sealed into the end of the sign tubing with the open end protruding into the Tube.

Neon Design: With only a Neon Signfew exceptions each sign is unique and must be designed to fit the desired Display within the confines of the available space. Considerations of the diameter of the tubing, the minimum radius the tubing can be bent, and the overall length of tubing the transformer can power all limit the final design. For example the smaller the diameter of the tubing, the brighter the Light. Conversely a smaller diameter tubing requires more power, thus limiting the over-all length of tubing one transformer can handle.

Manufacturing Process: It consists of bending the tubing and attaching the Electrodes, removing any impurities from within the tubing, then evacuating the air and adding the Gas.

Preparing the tubing: Lengths of glass tubing are cleaned and placed vertically in a coating machine. The machine blows a liquid phosphor suspension upwards into the Tube and then lets it drain back out the bottom. The Tubes are placed vertically in an oven which dries the coating. Color tints are applied in a similar manner. Tubes that are to be filled with Neon to form a red or orange Light or Argon to form a blue Light are left clear.

Bending the tubing: The glass tubing is carefully heated and softened using a variety of burners. Smaller hand torches are used to heat shorter lengths. Using the asbestos template as a guide, the tubing is bent by hand. The Tube benders do not wear protective gloves because they must be able to feel the heat transfer and the degree of softening in the glass to determine the right moment to make the bend. Tube bender attaches a short length of flexible hose, called a blow hose, to one end. The Tube bender gently blows into the hose to force the tubing back to its original diameter. Tubes with restricted diameters will not operate properly.

Several Sections of Glass Tubing: Most large Neon Signs are made of several sections of glass tubing. To make each section, the ends of two lengths of tubing are heated and spliced together. When the shape of the lettering or design has been formed for a section, an electrode is heated and fused onto each end. A small port, called a tubulation, is added to allow the tubing to be evacuated with a vacuum pump. This tubulation port may be part of one of the Electrodes or may be a separate piece joined into the tubing.

Glass Tubing: A process known as bombarding is used to remove any impurities from the glass, phosphors, and Electrodes. First the air inside the tubing is evacuated. After the vacuum reaches a certain level, dry air is allowed back into the tubing until the pressure is in the range of 0.02-0.04 inches (0.5-1.0 mm) of mercury.

Current Transformer: A very high-current transformer is connected to the Electrodes. For a length of tubing that may normally run on 25 milliamperes, 350-700 milliamperes may used for the bombarding process. The high current heats the glass to about 400°F (216°C), and the metal electrode is heated to about 1300°F (750°C). This heating forces the impurities out of the materials, and the vacuum pump carries the impurities out of the system.

Filling the Tube: Once the Tube has cooled, the Gas inserted under low pressure. The Gas must be free from impurities in order for the sign to operate properly and have a long life. The normal fill pressure for a Tube 0.6 inches in diameter is about 0.5 inches of mercury. Tubulation port is then heated and sealed off.

Aging the Tube: The finished Gas-filled tubing is put through an aging process. Sometimes this process is referred to as "burning in the Tube". The purpose is to allow the Gas in the Tube to stabilize and operate properly. A transformer, rated sLightly higher than the normal operating current is attached to the Electrodes. The Tube should come to full illumination within 20 minutes if Neon is used. It may take few hours for Argon. If a small amount of mercury is to be added to an Argon Tube, The droplet is rolled from one end to the other to coat the Electrodes after the aging process. Any problems such as a flicker in the Gas or a hot spot on the Tube indicate the tubing must be opened and the bombarding and filling processes repeated.

Installation and Mounting: Small Neon Signs are Mounted on their framework and wired in the shop. Larger Signs mounted in pieces and put into the building, other support structure where they are interconnected and wired. Large installations require months to install.

Quality Control: Careful manufacturing process required to produce a properly operating Neon sign. Neon sign should have a life of over 30,000 hours. As a comparison, the average 100-watt Light bulb has a rated life of 750-1,000 hours.

Series of Tests: This requires a series of Tests. Neon Signs must also meet the requirements of the National Electrical Code. Outdoor Signs must comply with local building codes in their construction and Electrical wiring.

Wishing you all the best,