In order to produce a quality sunlamp, every step in this process must be completed under strict quality controls.
It starts with the glass. A high-quality glass allows more of the energy created inside the lamp to get out and do its work – creating a cosmetic tan. The critical measure of glass quality is referred to as “transmission” and relates to the purity of the materials used to make the tube. Low transmission results in lower UV output; high transmission results in higher output. If the glass purity is too great, unwanted wavelengths, like UVC, can contaminate the lamp’s output. Lead-free glass is better for the environment.
Select a phosphor (or a blend of two or more phosphors). The phosphor coating on the inside of the tube is the source of a lamp’s tanning power. Many phosphor combinations give similar spectral results; but not all individual phosphor components are created equally. The best choice is the phosphor that has the highest purity, the highest efficiency (UV output per watt of power consumption), the slowest natural depreciation (decline in output over time), and the highest reliability in the manufacturing environment.
Coat the glass tube with the phosphor. Make a suspension of phosphor and a medium such as water (water as the suspension medium is better for the environment); keep it continuously mixed, so the phosphor remains in suspension. Coat the inside of the glass tube with a thin layer of this suspension; dry, then bake it. Coating thickness is a critical element: too thin, the UV output suffers; too thick and output is likewise diminished. There is an optimal thickness of the coating layer for each phosphor type and for each phosphor blend. The bake-out of the phosphor coating is also a critical process step. The baking time and temperature must be carefully controlled in order to drive out any impurities and properly adhere the phosphor coating to the glass – improper baking produces lamps with diminished performance, starting problems, or even dim areas.
Fill the glass tube with proper gasses. Inside a fluorescent lamp, the “normal” air we breathe is a contaminant, and seriously degrades the lamp’s performance. During the production process, air must be evacuated and replaced with an inert gas – typically argon or a mix of argon and neon. The gas type and pressure determine the lamp’s electrical operating characteristics. During the “exhaust/fill” process, the tube is filled with the inert gas and a precisely measured amount of mercury is dispensed into the tube (less is better for the environment) before it is sealed. Improper evacuation of air, the wrong gas mixture, incorrect fill pressure, or the wrong mercury dose will all affect the lamp’s operation and tanning performance. To avoid starting and appearance problems, and to assure maximum UV output, the exhaust/fill process must be done just right.
Seal the lamp before adding the bases. Sealing the glass tube is the final step in lamp creation. This seal is basically a glass weld that must be hermetic, or airtight. Without tightly controlled processes and quality control checks, the seal can finish with tiny, almost microscopic cracks. If these cracks are large enough, outside air can be drawn (or leaked) into the glass tube because of the extremely low pressure within. Remember, air is a contaminant if it gets inside the lamp. A lamp with small cracks that enlarge as it heats and cools during operation is called a “developmental leaker,” as the leak develops over time. Worst case: the lamp is dead on arrival at your salon. In other cases, it just stops lighting after a couple of tanning sessions. To avoid “no-lights” or extreme early failure, this critical step has to be completed just right, and verified through strict quality controls before the lamps are packaged and released for shipment.
When purchasing lamps, go with a company that offers reliable, long-lasting products that deliver top-quality performance and create the smallest environmental footprint.
