Advice on Aging Copolyesters
Eastman Chemical Co. (Kingsport, TN) has posted a technical tip on accelerated aging to its Web site. The plastics manufacturer advises that close attention be paid to a particular plastic’s characteristics during accelerated aging studies because each plastic material ages differently.
According to Glenda Eilo, global industry leader, medical specialty plastics marketing, “this aging protocol will reasonably represent the lifetime of a typical copolyester application. Note that aging copolyesters at higher temperatures for longer periods of time is not generally recommended.”
For example, aging for 240 hours (10 days) at 60°C and 50% relative humidity is equivalent to aging for 1,200,000 hours (133 years) at room temperature (23°C) and 50% relative humidity, reports Eilo. “Aging for this length of time or longer at 60°C may over age the material and provide an unrealistic expectation of what the properties would be after aging at room temperature.”
Eastman has performed accelerated aging on Eastar copolyester using strict guidelines and methodology, explains Eilo. “Eastar copolyester provides the required package integrity for a minimum of five years if good manufacturing practices are followed during extrusion, forming, package design, and sterilization and the packaging is stored at room temperature under normal conditions,” she says.