AES alkaline‑earth silicate bio‑soluble ceramic fiber possesses outstanding comprehensive performance, but it has clear upper‑limit temperature threshold, which shall be highly valued by design engineers and end‑users.

The standard long‑term continuous service temperature for regular AES fiber series is 1000℃‑1200℃. Under temperature below this threshold, fiber keeps stable amorphous structure, maintains low thermal conductivity and good thermal shock resistance. Once working environment stays persistently above 1200℃, devitrification reaction will occur inside AES fiber. Amorphous fiber transforms into crystalline phase.

After devitrification, fiber will turn brittle, mechanical strength drops sharply, easy to pulverize and fall off. The insulation layer will lose original protective effect. Even short‑term peak temperature exceeds limit value will accelerate material aging.

It does not mean AES fiber can work safely up to 1200℃ in all conditions. When there is high‑speed hot‑air scouring, flame direct impingement, the actual allowable service temperature should be properly reduced. If actual furnace working temperature is near 1200℃, we suggest adopting protective coating on AES fiber surface. For working condition stably over 1250℃, AES soluble fiber is not recommended, and high‑grade RCF or polycrystalline fiber should be considered as alternative. Correct temperature evaluation is the premise for long‑term reliable operation of AES insulation lining.