The fire-rated roller shutter is a common type used among fire doors. It has evolved from single-leaf to double composite shutters and twin-track twin-curtain inorganic fabric shutters. To meet stricter fire demands, manufacturers keep researching and testing. Early steel fire shutters were single-plate: the curtain was made of 0.5 to 1.5 mm thin steel strips cut and rolled into linked slats. The single-plate steel shutter has a simple structure, high strength, wind resistance, theft protection, good formability, and is easy to process, install, and use. But its fire resistance and heat insulation are weak.
After steady research by manufacturers, the composite steel fire shutter is now the most used type globally. Compared with the single-plate version, its improved structure keeps the old advantages and raises heat insulation noticeably. In curtain terms, the composite steel fire shutter is built from composite sandwich slats: two thin steel strips with an inorganic fiber insulation layer between them. The inorganic fibers makers use are mainly rock wool, mineral wool, glass wool, or aluminum silicate fiber. Because inorganic fiber has low thermal conductivity, the composite steel shutter insulates far better than the single-plate type.
The composite steel fire shutter is made by pressing the main and auxiliary plates in one pass. The surface is smooth, weld-free, and strong. RHidoor’s custom steel fire shutters are filled with fire-retardant insulation, which cuts heat radiation on the unexposed side. They hold fire for a long time, perform well, and can drop the water-curtain protection system, meeting the compartment needs of all class-1 fire zones. The vertical-lift steel fire shutter is fitted with an electric open-close unit and can run in automatic and linked modes with the fire control center.
A fire-rated roller shutter must keep high fire strength and a long fire duration at the scene. So its build is demanding: the whole system must survive high heat for a set time. How long it holds fire is the main pass-or-fail measure. Large buildings, per fire law, have a central fire control system. When a fire starts, the smoke sensor on the ceiling picks up smoke first and alarms the central system. The system identifies the zone and powers the fire shutters there, which descend at a set speed. When a shutter reaches about 1.5 meters above the floor, it stops to let people evacuate. After holding for a set time, it resumes descending until closed.
If a shutter’s fire strength is not enough during an incident, it cannot hold the fire compartment for the expected time. For the people inside, that is disastrous. So the fire duration that proves fire strength is the key check in quality testing.
So where do you need fire-rated roller shutters, and what do they do?
Common places include underground garages, hotel atriums, malls, and industrial buildings where gas, dust, or other explosion risks may appear during production, processing, handling, or storage.