Stahlin Non-Metallic Enclosures has been granted United States Patent No. 7,317,049 for SolarGuard®,”Resin Composition for a Sheet Molding Compound and Method.” SolarGuard’s double-protection formulation technology significantly enhances the molecular bond strength and cross-linking that occurs during the curing process in thermosetting polyester sheet molding compounds (SMC) to provide an additional benefit to anyone using non-metallic enclosures.
The SolarGuard system provides additional protection with a unique additive that fights polymer degradation by making it more difficult for UV light to attack molecular bonds of both primary molecular chains and cross-links of the resin matrix. It was developed specifically to beat the effects of outdoor enclosure exposure plus provide superior chemical and flame resistance in a non-halogenated formula. SolarGuard requires less maintenance than paint, wax or gel-coat alternatives used to prolong the life of electrical enclosures in outdoor environments.
Enclosure Users Need Protection From The Degrading Effects of UV Radiation on FRP Materials
The impact of Ultraviolet Radiation (UV) on electrical enclosures in outdoor environments has been a concern with non-metallic manufacturers for many years. Virtually all fiberglass products, when exposed to UV radiation, experience surface degradation. Visual changes to the composite fiberglass include surface fiber appearance, color change, and loss of gloss. This is a result of sunlight-initiated reactions with oxygen: photo-oxidation. Photo-oxidation occurs when the polymer molecules absorb sunlight and dissipate the excess energy by breaking chemical bonds. This UV exposure often resulted in a roughening of the exterior surface. Subsequent wind and rain can wash away this powdery byproduct and over time the glass fibers begin to show through to the surface. This is referred to as fiber blooming. The actual degradation of the FRP material will slow once these fibers are exposed, as they will then provide a degree of UV protection to the polyester material underneath. The rate at which the UV degradation occurs will vary depending on heat, humidity, and latitude with which the product is installed. Many end users of fiberglass products view this as being visually unappealing or in some cases as potentially having an effect on the physical properties of the end product.
When FRP products are exposed to UV radiation two factors can occur that have an affect on the end product. They are change in gloss and color. Gloss is one measurement of the ability of a material to reflect or scatter light. UV degradation can attack the SMC causing the polymer material to breakdown and the surface to roughen followed by fiber blooming. Over time the color of an SMC material can also be affected by this UV degradation. Pigments or colorants can be attacked and broken down similar to the way in which UV attacks the polymer chains. When this happens chalking, whitening, or some other form of discoloration can occur. Another form of color change occurs when molecular sub-groups are formed within the polymer matrix that is able to reflect light back to the observer. These sub-groups, also called chromophores, are portions of a molecule that selectively absorb specific frequencies of visible light thereby creating color. A consequence of photo-oxidation in SMC is the formation of these chromophores, leading to yellowing and other color change.
Stahlin Developed SolarGuard To Prolong The Life Of Enclosures
Over the years many manufacturers have come up with alternatives to prolonging the life of electrical enclosures in outdoor environments. Some of these are painting with various acrylics, enamels, epoxy paints, waxing, or using exterior gel-coats on molded products. While effective in prolonging the life of the product they can be expensive and require upkeep or maintenance out in the field. Several years ago Stahlin committed its research dollars to try to come up with a better solution. After months in the lab SolarGuard was created and added to its SMC formulation for testing.
There are many tests available to determine the effects of UV Radiation on enclosures and their materials. The SolarGuard SMC formulation has undergone extensive material and product testing to insure it meets or exceeds all relative industry standards. Such testing included:
- UL 746 C Polymeric Materials Used In Electrical Equipment Evaluations
- UL 50 Enclosures For Electrical Equipment
- UL 508 Industrial Control Panels
Additional test have also been performed, above and beyond these industry guidelines to aid in providing the end user with a premium product for a broad range of uses. These tests were performed using ASTM standards and other government approved procedures. Test standards and evaluation criteria are:
- Chemical resistance testing (submerged and vapor), 37 various chemicals (acids, bases)
- ASTM E162 Flame Spread
- ASTM E662 Smoke Density
- Particulate dust weight (NIOSH 05000), Acid gases HBr, HCl, HNO3, HPO4, H2SO4 (NIOSH 7903), Cyanide (NIOSH 7904), Metals (NIOSH 7300), VOC’s with TIC’s (EPA TO-14/TO-15), PAH (NIOSH 5506), Carbon Monoxide, Carbon Dioxide, Visual Fiberglass (NIOSH 7400), Ammonia, NO, NO2, HS2.
Additional UV testing has been performed under the following guidelines and evaluation criteria. Exposure testing is performed in Arizona in accordance with ASTM G90-98, Spray Cycle 1 (EMMAQUA, day spray with nighttime wetting).
- ASTM G 147-96 Standard Practice for Conditioning and Handling of Non-Metallic Materials for Natural and Artificial Weathering Test
- ASTM G 90-98 Standard Practice for Performing Accelerated Outdoor Weathering of Non-Metallic Materials Using Concentrated Natural Sunlight
- ASTM D 660-93 Method for Evaluating Degree Checking of Exterior Paints
- ASTM D 2244-93 Test Method for Calculation of Color Difference from Instrumentally Measured Color Coordinates
- ASTM E 308-96 Standard Practice for Computing the Colors of Objects by Using the CIE System
- ASTM D1729-96 Practice for Visual Appraisal of Color and Color Difference of Diffusely-Illuminated Opaque Materials
- ASTM D 661-93 Method for Evaluating Degree of Cracking of Exterior Paints
- SFTS-1 (Wash)) 92-03-30 Method of Cleaning Exposed Specimens Prior to Inspection, Method A, Washed With Deionized Water and Soft Sponge
- ASTM D 523-89 (1999) Test Method for Specular Gloss
- ASTM D 4214-89 Standard Test Methods for Evaluating the Degree of Chalking of Exterior Paint Films, Method D, Transparent Tape Method
EMMAQUA accelerated outdoor UV testing was developed by DSET Laboratories in the early 1960′s. The method employs Fresnal-reflecting solar concentrators that use 10 flat mirrors to uniformly concentrate natural sunlight onto specimens mounted in a target plane. These mirrors provide an intensity of approximately eight suns with the spectral balance on natural sunlight in terms of ultraviolet integrity. The test apparatus is a follow-the-sun rack with mirrors. The target board, located at the focal line of the mirrors, lies underneath a wind tunnel along which cooling air is deflected across the specimens. A nozzle is used to to spray the specimens with de-ionized water per established schedules. Because EMMAQUA provides an excellent spectral match to sunlight, it correlates well to subtropical conditions, such as Southern Florida, as well as an arid desert environment, such as Arizona.
Successful Enclosure Applications With SolarGuard Included in the SMC formulation
Customers of Stahlin Non-Metallic Enclosures have reported many successful applications of enclosures protected by SolarGuard. Listed below are just a few of the examples:
Carlsen and Associates: Winemaking Equipment
The goal at Carlsen and Associates is to provide the ultimate in functional, quality winemaking equipment to the wine industry. One of their more popular products is the Waukesha 130 Wine and Must Pump. It is a pump that will do virtually all phases of wine production. Their customers purchase their products because they know they will perform properly especially during the peak grape harvesting season. Their challenge was selecting an enclosure for their controls for the pump that had aesthetic appeal yet would also perform well in an harsh envirnoment. Stahlin’s Classic and J Series enclosures met this need. However one of the key deciding factors was that all Stahlin fiberglass enclosures were molded with SolarGuard® that guarded their equipment against damage from constant UV exposure. www.carlsenassociates.com
MicroGrow: Greenhouse Controls
An important part of MicroGrows product research and development focused on finding a reliable, protective housing of for the critical controls of the Growmaster Procom. When they first began building their products 20 years ago they used metal housings. Even though the controls were protected by metallic enclosure products, they found ourselves replacing the housings much sooner than we felt was necessary because they quickly became severely corroded. Several years ago MicroGrow began using a new non-metallic composite enclosure on the market that they felt might finally fit all of their needs: DiamondShield® because now the enclosures provided an additional bonus: SolarGuard that effectively has protected their controls during constant exposure to UV rays at their clients Greenhouse locations.. www.microgrow.com
Boundless Security Systems Inc.: Nail-and-GoT
To help law enforcement view criminal activity, record better video evidence than can be sent live over cellular networks, increase the number of cameras they can operate in a neighborhood, and stay within bandwidth usage limits, Boundless Security Systems, Inc., developed the Nail-and-GoT. Boundless faced the challenge of how to make it easy and practical for outdoor digital video surveillance systems to use readily available, public wireless communications networks, be moved every few days, and to be as benign in appearance as possible so they don’t scream, “Cameras Here.” they ended up chosing Stahlin’s enclosures because their products are made from a patented base material known as SolarGuard that is designed to provide improved resistance to ultraviolet wavelengths when used in outdoor environments. Now the Nail-and-GoT enclosure is able to withstand exposure to both UV and aggressive chemical attacks.
Solis Energy: Rugged and reliable Uninterruptible Power Supply (UPS)
Companies who cannot risk equipment failure during blackouts/brownouts or extreme environmental fluctuations have turned to Solis Energy for the most rugged and reliable Uninterruptible Power Supply (UPS). Solis Energy designs and manufactures a solution that delivers continuous, reliable power. Our AC>DC Outdoor UPS provides clean, uninterrupted power to critical 12, 24 and 48volt loads. The selection of each individual component for our UPS was very important. However, it became clear that the enclosure choice needed our special attention since most of our units would be placed in extremely harsh environments. For example, they could be located in remote desert locations where high heat is common or in a northern climate facing very cold and blizzard conditions. Plus, all of the units would have to combat the constant effects of ultra violet rays. Stahlin’s enclosures with SolarGuard has been able to protects their UPS units from UV rays.. www.SolisEnergy.com
More information: Stahlin