Polyhedron – Accelerated Weathering & Electrical Testing
Polyhedron Laboratories recognizes that the effect of weather conditions or chemical agents on the service life of plastics, polymers and elastometers are as significant as the basic physical properties of these materials. Polyhedron can conduct accelerated weathering tests according to ASTM G53-96, and resistance tests to ASTM D543-95, ASTM D471-98e2, ASTM D1693-05 and ASTM D5510. All ASTM standard descriptions below are paraphrased from the ASTM website (www.astem.org). Due to copyright restrictions, Polyhedron Laboratories cannot make available copies of standards. Standards can be found and are available at www.astem.org. Additionally, Polyhedron Laboratories offers customized accelerated weathering testing for predicting the lifetime of any material at any temperature under any set of conditions.

G154-04 - Practice for Operating Light- and Water-Exposure Apparatus (Fluorescent UV-Condensation Type) for Exposure of Nonmetallic Materials - This procedure deals with operating procedures and basic principles for using condensation apparatus and fluorescent ultraviolet (UV) to simulate the deterioration caused by sunlight and water in the form of rain or dew. This routine is focused on the method of obtaining, measuring, and controlling the procedures and conditions of exposure.

ASTM D543-95 - Standard Practices for Evaluating the Resistance of Plastics to Chemical Reagents - These procedures deal with the evaluation of all plastic materials including hot-molded, cast, laminated resinous products, cold-molded, and sheet materials for resistance to chemical reagents. These methods include provisions for reporting changes in dimensions, weight, strength and appearance properties. Standard reagents are defined to establish results on a comparable basis. Provisions are made for various stress conditions, exposure times, and exposure to reagents at elevated temperatures. The type of conditioning (wet patch or immersion) depends upon the end-use of the material. If used as a container or transfer line, samples should be immersed. If the material being evaluated will see only short exposures or is to be used in close proximity and reagent may spill or splash on the material, the wet patch method of applying reagent is recommended.

ASTM D471-98e2 - Standard Test Method for Rubber Property-Effect of Liquids - This test procedure deals with the required methods to evaluate the comparative ability of rubber-like and rubber compositions to withstand the effect of liquids under severe conditions. It is designed for testing samples cut from fabric coated with vulcanized rubber, samples of vulcanized rubber cut from standard sheets, or finished articles of commerce.

ASTM D1693-05 - Standard Test Method for Environmental Stress-Cracking of Ethylene Plastics - This test procedure deals with the determination of the susceptibility of ethylene plastics to environmental stress cracking. Under situations of stress and in the presence of environments such as wetting agents, soaps, detergents or oils, ethylene plastics may exhibit mechanical failure by cracking.

ASTM D5510-94 - Standard Practice for Heat Aging of Oxidatively Degradable Plastics - This procedure defines the exposure conditions of plastics at various temperatures when exposed to hot air for extended periods of time. The effect of heat on any particular property may be determined by selection of the appropriate test procedure and specimen. Additionally, this procedure should be a guide for evaluating the thermal-aging characteristics of materials as calculated by the change in some property of interest (in other words, embrittlement by means of elongation loss). This procedure measures the kinetics of degradation along with Arrehenius parameters and prediction of material lifetimes.

Additionally, Polyhedron can perform electrical testing, such as Dielectric Strength (according to ASTM D149-97a) and Resistivity (ASTM D229-01).
 
ASTM D149-97a - Standard Test Method for Dielectric Breakdown Voltage and Dielectric Strength of Solid Electrical Insulating Materials at Commercial Power Frequencies - This test procedure deals with methods for the determination of dielectric strength of solid insulating materials at commercial power frequencies, under specific conditions. Tests shall be performed at 60 Hz, but may also be used at any frequency from 25 to 800 Hz. The procedure can also be used at various temperatures, and in any liquid surrounding or suitable gaseous medium. This procedure is commonly used to determine the dielectric breakdown voltage through the thickness of a test sample (puncture). Additionally, this test method can also be used to determine dielectric breakdown voltage along the interface between a solid specimen and a liquid or gaseous surrounding medium.

ASTM D229-01 - Standard Test Method for Rigid Sheet and Plate Materials Used for Electrical Insulation - This test procedure deals with the method for testing rigid electrical insulation manufactured in plate or flat sheet forms. These materials are used as terminal boards, spacers, voltage barriers, and circuit boards.

The effect of weather conditions or chemical agents on the service life of plastics, polymers and elastomers are as significant as the basic physical properties of these materials. Polyhedron laboratories can conduct accelerated weathering tests by ASTM G53 and resistance tests by ASTM D 543, ASTM D 471, ASTM D 1693, and ASTM D 5510. Customized accelerated weathering testing is available for predicting the lifetime of any material at any temperature under any set of conditions.