PANDUIT: Electrical Full Line

For technical assistance in the U.S., call 866-405-6654 (outside the U.S., see inside back cover for directory) ELECTRICAL SOLUTIONS B1.99 B2. Cable Accessories C1. Wiring Duct C3. Abrasion Protection C4. Cable Management D1. Terminals D2. Power Connectors E1. Labeling Systems E2. Labels E3. Pre-Printed & Write-On Markers F. Index B3. Stainless Steel Ties C2. Surface Raceway E5. Lockout/ Tagout & Safety Solutions B1. Cable Ties A. System Overview D3. Grounding Connectors E4. Permanent Identification Over a period of time, ultraviolet light (a component of sunlight) attacks most plastic materials and reduces their properties by breaking the molecular chain. The material breakdown is accompanied by reductions in tensile strength and elongation, increased brittleness, color changes and loss of surface gloss. Carbon black, which is used in Panduit nylon, polypropylene, and acetal cable ties, is one of the most effective stabilizers known today. A uniform dispersion of carbon black provides good ultraviolet light resistance without adversely affecting physical properties. The addition of carbon black, or any other ultraviolet light stabilizer, prolongs the useful outdoor life of plastic products, but it does not totally eliminate the destructive effects of the light. Some plastics, such as TEFZEL ■ or HALAR ▲ , are intrinsically very resistant to ultraviolet light and do not require stabilizing additives. Weathering Test Methods In order to monitor the effects of ultraviolet light and the effectiveness of ultraviolet stabilizers, Panduit, in conformance with industry standards, adopted two methods of weatherability testing: Outdoor Aging and Accelerated Weather Aging. Outdoor Aging The Outdoor Aging method is probably the best and most realistic method of the two. It is conducted in accordance with ASTM D 1435 Standard Practice for Outdoor Weathering of Plastics, and allows the material to be affected by not only ultraviolet light, but by all other outdoor elements as well. Although this may more closely approximate an actual application, two drawbacks do exist. The period of time required to produce property decay and material failure may be quite long, and varying adverse chemical environments cannot be tested. Accelerated Weather Aging Accelerated weathering tests are conducted to estimate the rate of degradation due to a combination of ultraviolet light, temperature, and moisture. The methods used are in accordance with the following standards: • ASTM D 1499, Operating Light and Water Exposure Apparatus (Carbon-Arc type) for exposure to plastics • ASTM G 154-04, Operating Light and Water Exposure (Fluorescent UV Condensation type) for exposure of non-metallic materials The condition specified in ASTM D 1499 utilizes a water spray and a carbon arc to simulate natural sunshine. The test chamber is operated 20 hrs./day with a two-hour cycle of 108 minutes of simulated sunshine and twelve minutes of sunshine and water spray. The temperature of a black body inside the chamber is approximately 63°C (145°F) during the “sunshine only” portion of the cycle. Humidity is not controlled inside the chamber. The test chamber per ASTM G 154-04 uses fluorescent sun lamps to generate ultraviolet light only. A heated water pan produces condensation during a portion of the cycle. The daily cycle is composed of 20 hours of light followed by 4 hours of condensation. Black body temperatures during the light cycle are 50°C (122°F) and 40°C (104°F) during the condensation cycle. Panduit has also designed a special chamber, which is used to simulate the effect of acid rain and ultraviolet light on cable tie materials. The effects of other common chemicals, such as road salt, are also evaluated in this chamber. These methods are effective in quickly determining the ultraviolet light resistance of the various cable tie materials, but it must be emphasized that there are no exact correlations between accelerated aging and actual outdoor exposure. ■ TEFZEL is a registered trademark of E.I. du Pont de Nemours and Company. ▲ HALAR is a registered trademark of Ausimont USA, Inc. Weathering