Akon sells a variety of materials. Standard clear 20mil vinyl material and 13,18oz and 22oz vinyl materials are rated for 140 degrees Fahrenheit. However, if you have an application where 140 degrees of heat is present then the curtains can and will eventually fail.
The best example is an engine running with your foot all the way to the floor on the pedal. You are running it at its maximum ability and it will eventually fail. The same is true for using curtains at their max temp rating. They will last, but there is no way to guarantee how long. The material becomes very soft and grommets can pull out or rips can occur. If you need industrial high temperature rated curtains then view our line of heat resistant industrial curtains.