Before you buy a fire shutter, understand the materials. They determine how well the door performs when it counts.
Steel Fire Shutter Curtain
Made from cold-rolled or galvanized steel strip, typically 1.2 to 1.5mm thick. The slats are roll-formed into an interlocking shape. For composite fire shutters, each slat is two steel faces with fire-resistant insulation in between — rock wool, ceramic fiber, or aluminum silicate fiber. These have low thermal conductivity, keeping the back face cooler during a fire.
Inorganic Fabric Fire Shutter Curtain
Multiple layers: glass fiber base fabric, ceramic fiber blanket for insulation, aluminum foil for radiation reflection, and silicone-coated outer fabric. These curtains weigh about 5kg per square meter versus 25kg for steel composite — lighter weight means less structural load and easier installation for large openings.
Guide Rails
Usually galvanized steel. For special-grade fire shutters, the rails need to be deeper to accommodate the curtain's thermal expansion — standard depth is 80 to 120mm, special-grade can be 180mm or more. Rail anchoring must withstand the curtain pushing outward during a fire.
Barrel Shaft and Door Operator
The shaft is seamless steel tube sized by door width and weight. Fire-rated motors have thermal protection and enough braking force to hold the curtain. For gravity-descent shutters, the motor has a release mechanism that lets the door close under its own weight when triggered.
Control Box
Must accept fire alarm signals and provide position feedback. Should have battery backup for at least one complete cycle. The fusible link release is a separate purely mechanical device that bypasses all electronics.
What matters most: the fire rating test report. This document proves the door assembly has been tested to the claimed fire duration. Without it, you don't really know what you're buying.