CNC Press Brakes or Folders?

When considering the expansion of bending capabilities in a sheet metal workshop, the dilemma arises between choosing a press brake or a CNC folding machine. In reality, a bustling sub-contract sheet metal shop can enhance efficiency and cost-effectiveness by incorporating both machines. Therefore, the question becomes, “Why should you add a CNC folder to your list of equipment?” For those involved in product manufacturing, there are distinct applications that favour either process, making it beneficial to examine the unique features of these machines.

While both machines might lead to the same outcome, it is crucial to explore the key considerations…

How do they differ?

A press brake operates by utilizing a top tool, or punch, to press the material into a vee on a bottom tool, or die, thereby forming an angle. The prevalent method employed by most press brakes today is air bending, where the vee die’s two shoulders create three points with the punch’s tip to execute the bend. Conversely, a CNC folder clamps the material in a flat position and employs a folding beam to bend the material upward in a rotary action to achieve the desired angle.

Flexibility

Undoubtedly, a press brake is the more versatile machine. If your requirements involve handling a spectrum of bending tasks, ranging from thin to thick materials, without knowing what challenges may arise in the future, then a press brake is likely the optimal solution. Equipped with the right tooling, a press brake can bend heavier plates on narrower widths within the machine’s tonnage capacity. Additionally, various tools are available for specific tasks like hemming, over bending, and joggling.

Advantages of a CNC Folder

1. Handling Large or Heavy Parts: When bending large parts on a press brake, it often necessitates two operators to gauge and support the material during bending. This increases cycle time, manual handling, and the risk of injury. These issues can be mitigated with a CNC folder, which features a back gauge table for continuous material support, requiring the operator only to position the material against the back gauge fingers.
2. Working With Very Thin Material: On a press brake, gauging longer flanges in very thin material can be challenging, as the material may drop down under its own weight before reaching the back gauge. This issue is avoided on a folder, where the material is continuously supported.
3. Bending Small Flanges on Large Parts: CNC folders excel in bending small flanges on large sheets. Unlike a press brake, where the majority of the sheet protrudes from the front, folders ensure accuracy and prevent distortion by keeping the material on the back gauge table.
4. Bending a Range of Applications Without Changing Tools: Unlike a press brake, which may require tool changes for different material thicknesses and bending angles, a CNC folder can bend various angles and thicknesses without any tooling changes, saving significant time, especially during small batch work or urgent off-cycle production.
   
   Our EXR and EXL models feature a combi beam, where there is a row of straight tooling and the beam can rotate 180 degrees for a selection of other tools to be used, for fast and efficient folding.
5. Using Coated or Sensitive Material: Folders are effective at bending polished, coated, or other sensitive materials without marking, as the part remains securely clamped during the bending process. Press brake tooling may mark the material, necessitating a secondary clean-up operation.
6. Freeing Up Press Brakes for Specialized Tasks: In situations where press brakes are tied up producing large parts with two operators, shifting the production of these parts to a CNC folding machine allows for single-operator production. This leaves the press brake available for handling smaller, complex parts in thicker material and higher batch quantities, optimizing its efficiency.

While certain jobs can only be accomplished on a press brake and vice versa, there is a considerable range of applications where you have the flexibility to choose between the two machines.

For more information on CNC Press Brakes or Folders? talk to Selmach Machinery Ltd