Why Encapsulate UV Lamps with Protective FEP Coating?

Increase Lamp Performance in Temperature Extremes

UV-C Lamps

Modern UV-C lamps are similar to the conventional fluorescent lamps typically found in most commercial ceiling fixtures. Both lamp types are manufactured in, essentially, the same lengths and diameters. Both lamps operate using identical electrochemical processes: an electric discharge through argon gas strikes mercury vapor to generate a photon with a wavelength of 253.7 nm (typically called UV-C), which is invisible.

UV-C lamps differ slightly from their fluorescent counterparts in that the UV-C lamp’s glass envelope is a highly engineered, UV-C transparent material (quartz or “soft glass”). This “glass” allows the 253.7 nm wavelength to transmit through the lamp envelope unfiltered. Standard fluorescent lamps, however, use ordinary glass that is coated with phosphors on its interior surface. Thus, the UV-C energy is contained to excite the phosphors to glow (fluoresce) in the visible light range.

Protection Against Lamp Breakage

Fluorescent lamps became widely used in multiple applications in the late 1930s and it was not long before testing was begun to find a way to protect against lamp breakage. Results of that testing for fluorescent lamps, including plastic sleeves, are still employed today and are commonly found in “big box” stores such as Home Depot, Lowes, etc.

Protecting against lamp breakage in food preparation was not only a key focus, but it became mandated. According to the FDA: “…light bulbs shall be shielded, coated, or otherwise shatter-resistant in areas where there is exposed food; clean equipment, utensils, and linens; or unwrapped single-service and single-use articles.”

The use of ultraviolet disinfection has a broad range of applications and has seen strong growth in heating, ventilation, air conditioning and refrigeration (HVACR) systems in markets such as healthcare, pharmaceutical, food preparation/production and commercial buildings. Because ASHRAE recommends shutting down HVAC systems for 15 minutes should a lamp break occur, there has been a growing interest in protecting against the breakage of lamps by building owners and managers.

However, the common strategies used for protecting fluorescent lamps, primarily plastic sleeves, will not work for UV-C lamps. The material that is often used to protect fluorescent lamps blocks UV-C energy transmission.

EncapsuLamp Shatter-Resistant Covers

For this reason, UV Resources offers EncapsuLamp™ technology (see example on the right). EncapsuLamp is an FEP encapsulation material (Fluorinated Ethylene Propylene), and its molecular structure is such that, like quartz and soft-glass, it allows the UV-C wavelength of 253.7 nanometers to pass through. Encapsulated lamps hermetically seal UV-C lamps in case of breakage. Should an accident occur, broken glass and mercury will remain within the lamp protective shell.