Straightening machine is a forming process which aims to correct the flatness defects in rolled, drawn or extruded metals. The process consists of bending the metal sheet around sets of straightening rollers in alternate directions to exceed its yield point and achieve an even elongation to reduce internal stresses and homogenize those which cannot be eliminated completely. This is a cold forming operation which does not require heat treatment. The elongation in the material also removes the inherent stresses caused by the rolling process which are responsible for the surface flaws such as burrs and dents in finished metal products.
Straighteners are designed to work with a wide variety of different metals including ferrous and nonferrous metals, such as steel, aluminum, titanium, copper etc. Straightening machines come in different sizes and configurations depending on the requirements of the customers. These machines are designed by professional engineers in accordance with the prerequisite domain guidelines using top grade raw materials and latest technology to ensure a high quality product.
Powered straighteners use powered rollers to move the metal through the machine. These machines typically offer more accurate, more consistent and faster straightening than pull-through straighteners or all-in-one straightener-feeder machines. However, power requirements can vary significantly based on the size of the work rollers and centre distance spacing, as well as the maximum width and thickness of the material.
A common mistake when specifying a straightener is to assume that all types of materials will need the same amount of power. In reality, narrower materials can actually cause more stress and deflection on the work rollers than wider ones because they are closer together. These higher loads are concentrated at the centre of the rollers, which is furthest from the end journals and bearings that support them. This can result in reduced machine efficiency and increased wear of the work rollers. To minimize these effects, most machines are equipped with back-up rollers in one or more places on the work rolls.
Another issue with power requirements for straighteners is the need to factor in the maximum yield strength of the material. Most machines are rated for their ability to straighten mild steel with a 35 tons/sq cm yield strength, but this rating does not take into account that the actual power needed is often far greater than this. The type of material being processed can also influence the power required, as can the presence or absence of a torsion device to counter twists in the metal.
Whether your company uses solid bars or hollow profiles, a straightening machine can help you improve the quality of your end products and increase productivity by reducing time, energy and costs. Using a straightening machine can also eliminate waste caused by re-rolling and re-tightening. Danieli’s multi-roll straightening systems are engineered specifically for each application to deliver optimal bar/profile straightness. These systems are available in a range of bar diameters and lengths and are designed to meet the requirements of your production process.