The strength of plastics decreases at cold temperatures. For example, polycarbonate (PC) is an extremely tough plastic at normal use temperature and is sometime used as “bullet-proof glass”. However, at very cold temperatures (-40F), PC becomes brittle and will shatter like regular glass if struck at high impact speed. Every plastic has a ductile to brittle transition temperature (DBTT) at which the plastic becomes brittle and shatters upon high-speed impact. The DBTT varies depending upon the plastic. Generally, as plastic parts age, the DBTT temperature increases.
A CASE STUDY
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PROBLEM: AT WHAT TEMPERATURE DOES PLASTIC BECOME BRITTLE?
The strength of plastics decreases at cold temperatures. For example, polycarbonate (PC) is an extremely tough plastic at normal use temperature and is sometime used as “bullet-proof glass”. However, at very cold temperatures (-40F), PC becomes brittle and will shatter like regular glass if struck at high impact speed. Every plastic has a ductile to brittle transition temperature (DBTT) at which the plastic becomes brittle and shatters upon high-speed impact. The DBTT varies depending upon the plastic. Generally, as plastic parts age, the DBTT temperature increases.
