Roll formed shapes can be made from any alloy, pure metal or composite including steel, aluminum, bronze, copper, magnesium, titanium and zinc. The sheets, coils, rolls or strips may be pre-coated, painted, embossed or bare and are formed at room temperature, which often creates a stronger, more rigid product.
Roll forming is a continuous process, and aside from bending and forming the metal, the machines can be equipped with metal cutting, trimming and punching tools. Roll formers are used to produce many different products for the energy, construction, transportation, medical, highway safety, electronics, retail, material handling and storage industries. The parts and products are usually long, uniform in thickness and profile and are manufactured in large quantities.
Some of these products are aluminum angles, metal rings, steel channels, angle irons and metal wall panels. All of these products can be produced in stock quantities, but custom roll formed products can be created for specialized applications; roll formers are highly customizable, though roller placement requires attention from a trained professional.
The roll forming process begins when metal material is fed into the machine’s entry section. Each set of rollers, bends the metal a little more than the previous set until the shape has taken its form. Anywhere from 30 to 600 feet of metal can be processed per minute. After the metal has been rolled and shaped, it can be transferred to a cut-off press, where it is cut to pre-determined lengths.
If needed, some machines are equipped with punching tools that create holes in the product. The newly-formed products are ejected from the roll former onto a conveyor system from which they are manually removed. Modern roll formers are controlled by computers, allowing much more design complexity, less human error and a tight, uniform design tolerance, ensuring each roll-formed product will be exactly the same.
Control computers often can detect mistakes and product imperfection; they can also be equipped with self-diagnostic tools that report when repairs or mechanical adjustments are necessary. Because roll forming causes changes to the surface properties of a metal, roll formed metals often require little to no surface post-processing. Because roll formers are a cold forming process, they are generally very energy efficient. This makes them an appealing alternative to energy-intensive processes like extrusion.