Electronics Protection - March/April 2013 - (Page 7)

Feature 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. Exposed glass fibers due to UV degradation do not reflect a signifixcant loss in physical properties. Test from industry labs show only a small loss of strength. In programs of 10 to 15 years duration, losses of 5 to 10 percent in physical properties were noted. These losses cannot be solely attributed to weathering. It has been estimated that the maximum loss in physical properties due to UV damage is less than 1 percent per year of exposure. equipto New Material Formulations: Combat the Effects of UV Rays Over the years many manufacturers have come up with alternatives to prolong 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. Chemical composition of unsaturated polyester resin based sheet molding compounds play an important role in the material’s ability to resist UV degradation and its ability to weather outdoor environments. Industry standard formulations are primarily fire retardant isopthalic resin systems. These are systems in which the base resin contains bromine (halogenated) to aid in fire retardancy. The SMC formulation utilizes a neo-pentyl glycol (NPG) isopthalic based resin system that contains no bromine (non-halogenated) and has been developed to provide excellent outdoor weathering properties. In the SMC formulation, the combination of a stronger polymer backbone and a UV resistant additive gives the material double protection against the effects of UV degradation. Bromine in a thermosetting resin system bonds itself to the polymer chain during the manufacturing process of the resin. This bond is much weaker than the carbon-carbon bond of the polymer chain and is more easily broken under UV or heat energy. This is desirable for fire retardancy but is undesirable for weathering resistance. In the NPG system there are none of these weak links in the polymer chain and thus the UV energy required to break these links is greater and subsequently gives the SMC material better UV weathering characteristics. An additional proprietary additive in the new formulation is a UV absorber. This additive works to absorb UV energy and release it without damaging the polymer chain. This prevents the polymer bonds from breaking apart. This material will also absorb UV energy more readily than the links of the polymer chain thus providing increased protection of the polyester material and increased resistance to the damaging effects of UV radiation. In extensive comparison testing, the material outperformed other available formulations by as much as 60 percent in its ability to retain gloss and color after exposure to concentrated UV light. The material also maintained stability in thickness proving that its physical properties remain very much intact. Successful Applications Using Non-Metallic Enclosures in Harsh Outdoor Environments After reviewing the available options of materials for enclosures, a number of companies requiring protection for outdoor controls are choosing the non-metallic materials formulated with protection from UV rays . Below are just two examples of successful enclosure applications that have retained the original color, gloss and structural integrity after years of use. earthquake 2010:Layout 1 3/22/10 10:13 AM Page 1 Please see Stahlin continued on page 29 Protection from earthquakes and other threats When the ground starts to shake and things are being torn apart the last thing you want to worry about is the shock and vibration resistance of your system’s enclosure. O ur line of “Heavy Duty” modular, seismic hardened electronic cabinets meet NEBS seismic requirements of Telecordia GR-63 CORE through Zone 4, the most severe test. Without changing cabinet lines or your designs, Heavy Duty also meets requirements for: • Mil-Spec 810 and 901 • Shock and vibration • Mil-Std 461, IEEE 299, NSA -94-106 • EMI/RFI, FCC/VDE • Metric and more Documented proof and information to properly load our cabinets for your own seismic tests available on request. For personal assistance, or a catalog, contact us today. 800-204-7225 • 630-859-7840 • www.equiptoelec.com sales@equiptoelec.com • Aurora, IL 60506 ISO 9001:2008 RoHs Compliant Proven tough during the Chilean earthquakes March/April 2013 www.ElectronicsProtectionMagazine.com 7 http://www.equiptoelec.com http://www.equiptoelec.com http://www.ElectronicsProtectionMagazine.com

Table of Contents for the Digital Edition of Electronics Protection - March/April 2013

Electronics Protection - March/April 2013
Newer Technology Releases Next-Generation Power2U AC/USB In Wall Charging Solution
Specifiers of Enclosures for Components in Outdoor Applications: Be Aware of Material Selection Issues
How to Protect Electronic Circuits from Power Surges
Testing for Ingress Protection of Portable Electronic Devices
Increasing the Lifespan and Reliability of Electrical Components
From the Inside: The Configurable Plastic Enclosures Revolution
Tips for Selecting and Designing a Membrane Switch
HP Intelligent Series Rack Models Available for Networking and Demanding Server Requirements
Polyonics Antistatic Tapes Solve ESD Problems Before They Damage Static Sensitive Devices
OptoTherm Introduces IR LabMate Infrared Camera Solution
Falcon Electric Offers NEMA 3R/4 Enclosures with SSG UPSs
PEM SpotFast Fasteners Enables Flush Joining of Two Sheets
Industry News
Calendar of Events

Electronics Protection - March/April 2013