Basic roll forming

Roll forming machines fabricate specific configurations out of long strips of metal, most commonly coiled steel. In most applications, the required cross-section profile of the piece is specifically designed for the machine to bend the metal as necessary. Other than roll forming, these machines perform a number of metalworking duties, including material cutting and roll punching.

Roll forming machines, for the most part, work in a continuous cycle. The material is fed into the machine where it continuously makes its way through the stages of each operation, ending with the completion of a final product.

Roll Forming Machine

How Roll Forming Machines Work
A roll forming machine bends metal at room temperature using a number of stations where fixed rollers both guide the metal and make the necessary bends. As the strip of metal travels through the roll forming machine, each set of rollers bend the metal a little more than the previous station of rollers.



This progressive method of bending metal ensures that the correct cross-sectional configuration is achieved, while maintaining the cross-sectional area of the work piece. Typically operating at speeds between 30 to 600 feet per minute, roll forming machines are a good choice for manufacturing large quantities of parts or very long pieces.

Roll forming machine are also good for creating precise parts that require very little, if any, finishing work. In most cases, depending upon the material being shaped, the end product features an excellent finish and very fine detail.
Roll Forming Machine Line Basics

The basic roll forming machine has a line that can be separated into four major parts. The first part is the entry section, where the material is loaded. The material is usually inserted in sheet form or fed from a continuous coil. The next section, the station rollers, is where the actual roll forming takes place, where the stations are located, and where the metal shapes as it makes its way through the process. Station rollers not only shape the metal, but are the main driving force of the machine.

Roll Forming Basics

Roll Forming Basics
Roll forming, often called open-section forming, uses successive sets of roller dies to bend a strip of steel progressively until the desired shape is achieved. This process is very similar to traditional tube - and pipe making, but differs in that it can form more complicated sections.

Roll formed sections have an advantage over extrusions of a similar shapes. Roll formed parts are generally much lighter and stronger, having been work hardened in a cold state. Another advantage is that the part can be made having a finish or already painted. Labor is greatly reduced since volume is a major consideration for choosing the roll forming process.

Roll Forming Machine

Roll forming lines can be set up with multiple configurations to punch and cut off parts in a continuous operation. For cutting a part to length, the lines can be set up to use a pre-cut die where a single blank runs through the roll mill, or a post-cut die where the profile is cutoff after the roll forming process. Features may be added in a hole, notch, embossment, or shear form by punching in a roll forming line.

Both roll forming and tube and pipe forming involve bending steel with roller dies, with each pair of rolls working the strip progressively until the desired shape is achieved. How roll forming differs is that it lends itself well to prepunching, midpiercing, and postpunching all inline, as well as sweeping before cutoff.

Although the processes are similar and some of the equipment may be the same, there are differences in the design of a roll formed section and the tooling needed and in the layout and setup of the machine.



Process:
The process of roll forming is one of the simpler manufacturing processes. It begins with a large spool of metal strips, usually between 1 in. and 20in. in width, and 0.004 in. and 0.125 in. thick. This is held by a device called a dispenser. The metalstrip is then unrolled and fed into a machine starting with the stock feeder which is connected to the cutoff attachment. After the cutoff attachment, the metal strip is fed into the forming rolls. These mating die-set rolls are constructed to form the desired shape in stages sequentially by means of various shaped rolls. The layout of these rolls can be flower shaped as mentioned previously, progressive upper/lower rolls, side rolls, or as overhung spindle rolls.