Stockwell Elastomerics is a leading provider of LED gaskets and thermal pads to the outdoor LED lighting industry. LED gaskets and pads provide long term weather protection and reduce heat build-up, extending the life and performance of LED lighting and solid state lighting.
Stockwell Elastomerics manufactures custom LED gaskets and thermal interface pads for original equipment manufacturers (OEMs) and retrofitters of:
- LED roadway lighting
- LED street light fixtures
- Cobra head LED lights
- High mast fixtures
- Outdoor LED lighting
High power LED lighting is being specified for roadways, streets and public places such as parking lots and walkways. The higher initial investment for outdoor LED lighting is justified by the energy savings and reduced maintenance costs over time. In order to ensure a return on investment, outdoor LED lighting fixtures must be sealed against humidity, wind-driven rain, snow and ice for the life of the product – which is often rated for 10 years. Outdoor, wet location fixtures may be rated for UL 1598, IP66 or NEMA 4 (protected from high pressure water jets). Gaskets and seals must have excellent compression set characteristics along with high, long term resistance to stress relaxation to effectively seal out the ingress of dust and water over time.
Stockwell Elastomerics has been helping customers solve demanding outdoor gasketing applications for many years. Military and telecommunications base station enclosures have environmental gasketing and environmental sealing requirements similar to LED lighting applications where long service life is required. Silicone foam gaskets, silicone sponge gaskets and thermal pads have been installed in base stations deployed in remote locations across the world for many years. Many materials were considered, but only silicone has been specified due to its long term performance features.
Enclosure gaskets or housing gaskets are specified to seal exterior aluminum housings. Closed cell silicone sponge gaskets with pressure sensitive adhesive can be supplied slit to width on a roll, die cut or water jet cut to size. For large gaskets (over 12″ x 18″), gaskets can be designed with dovetail cuts in the corners that can be accurately water jet cut for assembly into the housing while vastly reducing material consumption. Request a sample dovetail gasket cut from R10470-M with adhesive backing to demonstrate this feature.
Aluminum enclosures often have a UV resistant powder coat finish. Stockwell Elastomerics manufactures UV-resistant silicone sponge and silicone foam gaskets with 3M 9490LE low surface energy acrylic adhesive, 3M 9485 (listed in UL 746C) acrylic transfer film adhesive and 3M 6038PC low fogging adhesive. Sample swatches can be requested to confirm compatibility with a specific housing finish.
Bezel gaskets are used with LED lighting designs such as high mast fixtures and cobra head luminaires. Gaskets are die cut from .032″ or .062″ thick silicone foam and compressed between the bezel and the optical system. The gaskets can be compressed 50% without damaging the cell structure and sealing properties, permitting a weather-proof seal around each individual LED. Stockwell Elastomerics offers fast-turn water jet prototypes when a CAD file is provided. Samples can be cut from HT-800, HT-870 (UL 1570, UL 1571, UL 157, UL 50) and other long lasting silicone foam materials for evaluation.
Excessive heat build up rapidly reduces the life of LED lighting units. The electronic driver or solid state circuits that power the LED lamp must be designed to reduce heat build-up. Thermal pads are used to promote heat transfer from the LED driver to the heat sink or heat sinking housing. This requires an efficient thermal interface from the driver to the metal housing which often functions as the heat sink.
Stockwell Elastomerics has extensive experience in producing thermal interface pads required for LED lighting applications. LED thermal pads can be die cut from thermally conductive materials such as Bergquist .005″ thick Q-Pad3, .005” thick T GON 805 Graphite Foil or .020″ to .040″ thick thermally conductive silicone rubber. Thermally conductive silicone may be preferred where conformability to surfaces is required. These materials are designed for long term performance in thermal transfer applications. Stockwell Elastomerics offers samples from an inventory of thermal transfer materials for evaluation. Water jet cut samples are available when a CAD file is provided.
Retrofitting existing street lights involves reusing the existing light fixture while gutting the housing and installing a new LED lighting system. For street lights and other applications, the retrofit is typically done with the light in place. Instead of re-sealing the fixture with dispensed adhesives, retrofitters are using screwed-in retrofit gaskets to complete the LED lighting installation. Stockwell Elastomerics can work with LED retrofitters to make custom gaskets and thermal pads to make retrofitting efficient and effective.
Written by Stockwell Elastomerics’ President Bill Stockwell, this whitepaper provides information about the types of gaskets used in LED lighting fixtures and material selection for LED lighting enclosures / housings. From the whitepaper’s executive summary:
This brief on Specifying Gaskets for Outdoor LED Lighting Fixtures discusses options for gasket materials and gasket types that will last and perform for the anticipated life of the outdoor LED lighting unit. The best material for long-term performance is silicone rubber. This paper provides the designer a comparison between the performance properties of traditional gasketing materials and readiliy available silicone gasketing materials and adhesive backings. Silicone withstands the broad temperatures, weather and long term exposures of outdoor lighting.
Contact Us for further assistance with gaskets and pads for LED lighting applications.