LED headlight technology challenges the automotive industry



In cars, conventional halogen headlamps are increasingly being phased out in favor of more modern technology. While standard halogen lamps are still used in the subcompact class, xenon headlamps are now standard in midsize cars. Premium vehicles already feature tomorrow's LED headlamp technology. In order to guarantee ideal clarity and reliability, headlamps must be protected from dust and dirt, deposits, water and condensation. In the case of LED headlamps, automakers and headlamp manufacturers face new challenges. "Cold" LED headlamps encourage condensation There are many ways for moisture to reach the interior of a headlamp. One moisture source is permeation, where moisture passes through the plastic and into the housing. The most significant source is moisture absorption/desorption out of the plastic lamp components. Just a few drops of water can cause a significant amount of condensation to form within the headlamp. Condensation is a physical phenomenon that typically occurs at the coldest spots. The heat an LED lamp generates in operation is radiated toward the rear - not toward the glass at the front, as in a halogen or xenon lamp. So the coldest area of an LED headlamp is the lens at the front, and any condensation that forms will impact lens clarity. This can lead to customer complaints and ultimately to warranty claims. Replacing an LED headlamp is extremely costly, since LED headlamps are roughly ten times as expensive as conventional halogen lamps. Headlamp manufacturers and OEMs are understandably keen on solutions that reduce the frequency of these types of warranty claims. Not to mention the damage their brand image could potentially suffer whenever owners complain about foggy or dirty headlamps. Vents extend the service life of front headlamps There are several common venting solutions for equalizing pressure and minimizing condensation in front headlamps. Some of these are open systems, which do a good job of equalizing pressure but have severe limitations in terms of preventing particles from entering the housing. GORE® Automotive Vents offer a reliable solution to this problem. They feature an expanded PTFE (ePTFE) membrane with pores that allow air to pass. This means any build-up of pressure within the lamp housing is constantly equalized, moisture can escape, and condensation is minimized. As they are roughly 20,000 times smaller than a water droplet, the membrane's pores also stop water, dust and dirt particles and deposits in their tracks, down to a size of 1.0 micrometer. GORE® Automotive Vents are equally suitable for use with halogen, xenon and LED headlamps. As LED technology becomes more widespread in headlamps, so too is the critical need for reliable venting solutions. The sensitive electronics these headlamps feature must be protected from water and dirt throughout the vehicle's lifetime. That is the only way to guarantee that headlamps function at their best - and to make sure that, as elements of growing importance to automotive design, they never lose their sparkle. Gore