Rullform

Rullform, or roll forming in English, is a continuous metal forming process in which a strip of sheet metal is fed through a succession of paired rolls. Each roll group makes a small bend, and through many stands a constant cross-section profile is produced. The finished length is cut to size, often after additional operations such as punching, notching, or coating.

The process is best suited for long, constant-section profiles such as channels, angles, tees, Z-sections, U-sections, and hollow boxes. Common materials include carbon steel, stainless steel, aluminum and galvanized steel. Typical thickness ranges from light to medium gauge and depend on material, equipment and grade; manufacturers may handle roughly 0.3 mm up to several millimeters.

Equipment and setup involve a coil feeding system (uncoiler and straightener), a sequence of roll stands, and a final cutoff device. Many lines include pre-punching, post-forming finishing, and sometimes surface treatments or coating integration. The technology is designed to produce long lengths with minimal waste and high repeatability of cross-sectional geometry.

Advantages of rullform include high production speeds, continuous output, good dimensional accuracy along the length, a smooth surface finish, and relatively low material waste. It is economical for high-volume production of identical profiles. Limitations include a high tooling and setup cost, and suitability primarily for fixed cross-sections; changing the profile requires new tooling and process reconfiguration, making it less flexible for short runs or highly variable shapes.

Applications encompass construction and building products (purlins, studs, roofing and wall profiles), automotive trim, appliances, and electrical enclosures, where consistent, long-length profiles are required.