ERBEND MFB for Roofing Trim Hemming

The ERBEND MFB STEEL SHEET FOLDING MACHINE supports programmed open and closed hemming with ERFOLD BASIC, making it a candidate for bringing compatible roofing-trim production in-house. Select the configuration around the required hem, prepainted material and complete profile—not ordinary bending capacity alone.

Open and closed hems need different results

An open hem leaves space inside the returned edge. Concealed-fastener trim can use that opening to hook onto a supporting cleat, so engagement clearance is a functional dimension rather than a cosmetic preference. A closed hem brings the return against the parent sheet; it is not an interchangeable substitute for an attachment hook.

Roof-edge trim and custom flashings therefore need drawings showing the shape, dimensions, angles, each hem type and the finished face. Include the mating cleat detail when attachment depends on it. “Hemmed edge” alone does not define the section the folder must make.

What the MFB brings to recurring trim work

The MFB is a single-station motorized folder for individual flat blanks. Its clamping beam holds the sheet while a pivoting folding beam forms the projecting edge. The motorized backgauge establishes position, and the rear table supports the sheet. This is blank-by-blank folding and hemming, not continuous roofing-panel roll forming or seam closing on an installed roof.

ERFOLD BASIC saves material type, thickness and length with programmed steps for angles, radii and open or closed hemming. Recurring flashing orders can reuse those instructions rather than entering them from scratch. Specify the actual control package in the quotation; a graphical interface and the ability to program a hem are separate selection questions.

Choose length, tooling and adjustment together

MFB 2030, 2525, 3220 and 4215 working lengths are 2,050, 2,550, 3,200 and 4,200 mm respectively. Match working length to the longest blank, then assess the full section through its intended bend-and-hem sequence.

Segmented goat-foot tooling, alternate beam geometry and expanded backgauge and sheet-support arrangements are available configuration choices. Consider them where previously formed legs restrict access or a broad blank needs support. Use a clearance drawing for the quoted build, including its tooling and finished-profile removal path, rather than relying on a family opening-height figure.

If the selected package has manual folding-beam adjustment, program recall does not move that adjustment. Ask whether manual or motorized adjustment better suits the frequency of material and profile changes. A saved recipe does not turn a manual setting into a controlled axis.

Prepainted material can set the hem limit

Prepainted-sheet formability depends on both the substrate and coating. A tight hem can exceed that combination’s flexibility even when the machine can perform the forming movement. Use the material supplier’s guidance for the actual grade, thickness and finish; do not assume every painted sheet tolerates a flattened closed hem.

ASTM D4145 evaluates coating flexibility and adhesion under bending. Bend direction and specimen temperature can affect its results. Applicable T-bend data informs the material decision; it is not an MFB capacity rating or a universal production-hem specification.

Contact marking is a separate concern. Rough tooling, inadequate clearance and poor alignment can damage the painted surface. Suitable coating flexibility does not remove the need for appropriate tooling contact and a material-compatible setup.

Request a quote for the finished hem

The application-specific quotation should address hemming capability for the actual material, strength, length and return geometry, including how the required open gap or closed return will be controlled. A programmed hem function is not a guaranteed finished-gap tolerance. Request a representative forming evaluation where those requirements determine purchase fit.

Production fit also depends on blank preparation, support, repositioning and removal—not just the programmed forming sequence. Compare those movements using the typical batch mix and available handling space before assuming that a longer table or upgraded control will shorten the complete trim cycle.

I’m Jon Williams, a Sales Executive at Mac-Tech. I can help assess the MFB configuration, material orientation, sheet support and production flow, then work toward an application-specific quotation. Call me with dimensioned trim drawings showing hem types and the finished face, a mating cleat or sample, material and coating specifications, supplier forming guidance, your longest blank and typical batch quantities.