Evaluation Of Plastics Using A Modified Indoor Lighting Exposure Test

摘要

Significant design changes to an existing product can elicit a variety of concerns from both new and existing customers alike. Corning faced just such questions as it redesigned its flagship local area network (LAN) housings. To validate design choices and address specific customer concerns, Corning developed a test plan to provide quantifiable data concerning the potential physical and aesthetic degradation of three transparent polymeric materials following accelerated exposure to indoor lighting. The duration and intensity were designed to simulate office lighting conditions that would be seen over the expected life of the product. A fourth material, which had been used in other indoor products for the past 15 years, was used as the benchmark. Four separate ASTM specifications were utilized to produce a comprehensive and relevant test regime. 1. ASTM D4674 "Standard Practice for Accelerated Testing for Color Stability of Plastics Exposed to Indoor Office Environments" 2. ASTM D523 "Standard Test Method for Specular Gloss" 3. ASTM D2244 "Standard Practice for Calculation of Color Tolerances and Color Differences from Instrumentally Measured Color Coordinates" 4. ASTM D638 "Standard Test Method for Tensile Properties of Plastics." A total of four transparent resins were exposed to accelerated indoor lighting conditions and evaluated at 30, 60, and 90 day intervals for color, gloss, and tensile properties. Two of the resins were ultraviolet (UV) stabilized while the other two were not. Not only did the testing ensure the new product materials would meet customer performance and aesthetic expectations, it also provided quantifiable data that guided the material selection to be presented in follow-on voice of the customer (VOC) sessions.