What are sectional doors made of and what determines their resource?
Sectional lifting gates are a common solution for garages, warehouses and industrial openings: the panel panel goes under the ceiling, does not require space in front of the building and closes the opening with good tightness. The design, configuration and execution options for different sizes of openings are collected on this page. Let's look at what the structure consists of, what materials work in it, and how it relates to the resource.
Why is the panel being layered?
The sectional door leaf is not a sheet of metal, but a sandwich panel: two steel sheaths and an internal insulating layer. Metal is responsible for rigidity and impact resistance, filler is responsible for thermal conductivity and sound. The multilayer construction works like a box section: with a small thickness, the panel holds its shape and does not "play" in the wind. The connection of the layers is important no less than the thickness: the stratified panel loses its rigidity and begins to deform in the opening.
Metal, coating and corrosion
The panels are made of thin-sheet steel with a protective zinc layer and a polymer coating. The exterior works in an aggressive environment: precipitation, reagents from roads, humidity changes. The quality of the coating is checked not on the day of installation, but after several winters – the edges of the panels, the cut lines and the mounting points are the first to corrode. For industrial facilities and coastal areas, this is the number one criterion of choice: metal thickness and coating, not just "beautiful texture".
Springs, guides and balancing
The weight of the web is compensated by a balancing system – torsion springs on the shaft above the opening or tension springs on the sides of the guides. The torsion circuit distributes the load on the shaft and bearings and is considered more resource-efficient for heavy and wide canvases; tension springs are simpler and more compact, they are chosen for light gates. The gate's resource is determined not only by the spring, but also by the entire system: guides, rollers, bearings, fasteners. The wear of one node shifts the load to the rest, so maintenance is an inspection of all the mechanics, not a replacement of a burst spring.
Tightness and energy of the opening
Seals run along the perimeter of the canvas and at the joints of the panels: they dampen blowing, noise and vibration. The lower profile is pressed against the floor, compensating for the irregularities. The microclimate in the room and the load on the drive depend on the tightness: the misalignment of the web forces the automation to work with overload and reduces the resource of the entire system.
Automation and security
The drive is selected with a margin in terms of weight and size of the web. The operating minimum includes stop photocells, a warning lamp and a manual release to