Not much has changed since the days of Mr. Thomas Alva Edison. The light bulb belongs to those few things in our environment that changed very little.

The same applies to the price. The price of a light-bulb today is almost same as what it was in the beginning of the 20^th century.

Very often people have questioned me whether it is not possible to make those lamps with a longer life and the answer has always been “ yes “. Lamps and its filaments however are designed to live only 1.000 hours as it is the optimum lifespan during which the lamp will provide whilst maintaining an acceptable light-radiation (lumens) against an acceptable quantity of energy (Watts). We can increase the life but the light-radiation would go down dramatically where-as energy consumption would remain almost the same.

Incandescent lamps mainly radiate heat. As a matter of fact they are more a heat source than a light source.

LOHUIS aims at that all incandescent lamps should be banned and replaced by energy saving lamps. Imagine that in hot countries people pay a lot of money for the energy used by incandescent lamps and then again they spend a lot of money for the air-conditioners to keep it cool!

Even though the use of energy saving lamps is rapidly increasing as their cost is coming down there is still a huge population that either does not understand the advantages of energy saving lamps or simply cannot afford the initial purchase of those lamps.

Against every 1 piece of energy saving lamp this world still uses more than 10 pieces of incandescent lamps.

Production-equipment for making electric light bulbs is expensive. Major suppliers in Europe like Badalex, Tungsram and Falma can supply these equipments for prices between US$ 1 to 3 million and for that kind of money people can buy machines that will produce 1.500 to 3.000 bulbs per hour with not too many workers.

LOHUIS is of the opinion that in developing countries we have to emphasize on reducing capital-outlay i.e. reduce the value of investments and use manual labour when such is cheap and when there is a high rate of unemployment.

For this purpose machines have been developed which produce about 1.200 lamps per hour using about 20 workers on the machines and packing-line.

Incandescent Lamp Assembly

The first step in assembling an incandescent lamp is the preparation of the "mount", consisting of the filament and the supporting parts. The flare, the combined arbor and exhaust tubing, and the lead-in wires are correctly placed and gas flames are applied to the assembly. The heat softens the two glass parts, causing them to fuse with the dumet of the lead-in wires embedded in the glass. Next, two jaws apply pressure to the softened glass, forming what is known as the "press".

While the glass is still soft, a blast of air is blown through the exhaust tubing causing a hole to open in one face of the press. This is used to evacuate air from the bulb and afterwards fill the bulb with the appropriate gas.

The end of the glass arbor is then softened by gas flames and shaped to form the "button". Support wires are inserted into the soft glass of the button. The ends of the lead-in wires are then flattened and bent at the point where they are to be clamped to the filament. The clamping of the filament and the coiling of the support wires, around the filament coil completes the mount.

In the next operation, the glass bulb is placed over the mount and gas flames are applied to the bulb's neck at a point opposite the flare inside the bulb. The softened glass of both bulb and flare fuses together and the unused end of the bulb, or "cullet", falls off. This is known as "sealing in". During this operation, while the glass is still soft, shoulders are formed on the bulb to provide a seat for the base. This insures accurate over-all lamp length and precision alignment of the axis of the base with the axis of the bulb. It also provides for a stronger basing.

Next, one of the most exacting operations in lamp making: the process of removing the air from the bulbs, and in type C lamps, replacing it with gas.

The sealed-in bulbs with the exhaust tubes connected to vacuum line posts are passed through gas flames. The resulting high temperature vaporizes any moisture in the bulbs. This vaporized moisture and most of the air is then withdrawn by a vacuum pump.

The bulbs are then flushed out with an inert gas as many times as necessary, removing residual vapour. In the final stage, the bulbs are filled with the required amount of the desired gas and "tipped off" by fusing the exhaust tube.

Following the "tipping off" operation, the sealed-in bulb is ready for the base. Contrary to what you might think, the base plays no role in sealing the bulb. It merely supports the bulb and provides the connection between bulb and socket.

To connect the base to the bulb, the base is filled with a soft cement and placed on the bulb with one of the lead-in wires protruding through the centre eyelet and the other wire positioned between the bulb and the edge of the base.

The cement is hardened by applying heat, the ends of the lead-in wires are cut off and the wires automatically soldered to the base.

While the lamps are on the basing machine, they are lighted five different times to set wire structure. Prior to final packing, they are again lighted once again and inspected.