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ABM G-100 Roll Forming Process
Here is how all the ABM panels and ABX panels are made.
During rollforming, Sheet is fed from a coil through a series of roll stands to progressively change the shape of the flat steel Sheet into a shaped panel. The rollformed panel has a distinct shape that provides a desirable appearance plus stiffness to the steel sheet.
Following only applies to painted panels:
Rollforming of pre painted galvanized steel Sheet causes cracking of the paint coating. It is often called as crazing," "microcracking" or "tension-bend cracking. The cracks that form are restricted to the coating metal; the steel is not cracked. After weathering a few moths or years, fine cracks |
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| may develop in either the paint or the zinc coating on the tension side of the bend. White corrosion products might be observed around the fine cracks in the paint on the tension bends since the products of zinc corrosion are white. As the corrosion progresses, the zinc underneath the paint is consumed and the paint flakes off since there is nothing for the paint to adhere to. Red rust may subsequently developed on the underlying steel(Figure 1). |
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Here at A.B.Martin we greatly reduce this problem by heating the prepainted sheet using infra-red heaters prior to entering the cut to length shears and forming rolls.
Roll-forming in this manner, at temperatures in the range of 120°F to 170°F, can significantly reduce the incidence of tension-bend cracking. Warm roll-forming not only significantly reduces tension-bend cracking in the paint film, but also in the metallic coatings of both zinc and zinc-aluminum alloy-coated products.
The roll-forming temperature has a significant effect on the development of tension-bend cracks on prepainted HDG. The
effect of warm roll-forming on prepainted ABM G-60, G-100 were evaluated at different temperatures ranging from 40°F to 160°F during the production roll-forming of a typical building panel design. The number of cracks developed on the tension bends was significantly |
reduced on panels that were formed on warm summer days with the ambient temperature at 92°F in comparison to those formed in the colder spring days. Cracks were not observed either in the paint or in the metallic coating on the panels formed at the elevated temperatures, where the forming temperature was between 140°F to 160°F versus room temperature formed at 59ºF` (Figure 2). Warm roll forming not only improved the ductility of the paint but also improved the ductility of the zinc coating. Warm rollforming at 120°F or higher was sufficient to eliminate the majority of cracking in the zinc coating
The Rollformer is also custom built by Bradbury Company with an engineered tooling design that puts less stress on the paint while forming. |
59ºF |
146º F |
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