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Roll Forming is a continuous metal forming process which bends or “forms” Sheets, Strips or Coiled Stock into pre-designed shapes or profiles by passing the metal between successive pairs of Rolls that increasingly (gradually) shape it till the desired cross section is achieved, thereby adding strength and rigidity to light weight metals. Except for a slight thinning of the metal at the bend radius, the metal thickness does not get altered.
Almost any material that can be formed to the desired radius at room temperature can be roll-formed. The more ductile the material, the better it will form. This process can handle ferrous, non-ferrous, hot-rolled, cold-rolled, polished, plated or pre-painted materials as well.
Metals as thin as 0.127 mm and as thick as 19 mm can be roll formed depending on the machinery.
Normally cross-sectional tolerances from +/- 0.25 mm to +/- 0.78 mm can be achieved but if better tolerances are required, a material that is amendable to such tolerance should be chosen.
ROLLS SHOULD BE DESIGNED FOR A PARTICULAR MACHINE AND INTERCHANGING THEM CAN LEAD TO MALFORMATION OF PROFILES.
TYPICAL TOLERANCES :
Angular tolerance +/- 1°.
Twist should be less than 5° in 3 m length of formed section.
Length of leg should be 3 times the material thickness.
Bend radius should be equal to or greater than the material thickness.
Springback can be engineered out during tool design by overforming the material beyond its anticipated shape. Endflare can be eliminated or atleast, reduced, by proper tool design.
OPERATING PARAMETERS :
The Variable Parameters in the Roll Forming Operation include power requirement, speed, complexity of profile, number of rolling stations etc. These Parameters are determined by the type of material, its width, thickness, coating on material if any, and the accuracy required.
Apart from these, Auxiliary Operations such as pre-punching, embossing, curving, coiling, and cut-off also influence the parameters of Roll Forming Operation.
APPLICATIONS :
Automotive
Trucks & Buses
Building Construction
Highway Construction
Office Furniture
Home Appliances
Rolling Shutters
Traffic Barriers
Bicycle Rims
Medical Equipments
Marine Construction
Agricultural Equipments
Railways
Heating Ventilation & Airconditioning (HVAC)
Aircrafts
Corrugated Roofings.
and many more...
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