FOCUS ON BENDING
FLEXIBLE FOLDING
“ The folding process is suitable for flexible applications because the tooling is not specific to the material thickness or angle required .”
We highlight a selection of the latest new global folding technologies and innovations .
For sheet metal folding operations , and particularly for bending items using thin materials that are long , wide and with short flanges , folding machines ( folders ) are a good fit . This is because they allow the material to rest on the folder bed for easier handling . They are also inherently accurate as they ‘ fold ’ any sheet dimensional errors into the first bend , providing more accuracy in overall part sizes .
Rapid , efficient and precise , they service a range of industry sectors for many different products and project types . Folders are easily identified by their large support tables and swinging ‘ folding beam ’, which bends the flange while the workpiece remains flat on the support table . These machines are suitable for many scenarios , especially for large blanks that would otherwise be difficult to handle .
“ During the folding sequence , the blank rests on the sheet support table . A gauging system positions the part to the bend line . The upper and lower beam clamp the blank . During the bending cycle , the folding beam moves up around a pivot point . On up-down acting machines , the folding beam moves upwards or downwards , depending upon the bending direction ,” explained folding specialist , RAS .
Process benefits
There are many levels of folding machines , but all of them follow the same sequence for air-bending a desired angle : position - > clamp - > bend . The process is suitable for flexible applications because the tooling is not specific to the material thickness or angle required . “ Universal ” tool geometries allow for unlimited angle possibilities and are rated up to the maximum machine capacity and height . These tools should last for many years because of the swing-beam folding process . Flanges are bent to the correct angle with flat tooling that eliminates scratching or sliding on the workpiece . Not only does this equate to better quality parts , but it also means almost zero tool wear .
There are several types of folding machines . On systems equipped with segmented clamping tools , a new part can be set up by rearranging the tool segments on the tool rail . Machines without automatic tool changers still simplify the set-up process by advising the operator where to put tool stations . This common tooling allows for rapid changeover between parts and makes it easy for a single employee to program , operate and set up the machine for any compatible part .
The clamping tool of a folder enables the folding beam to form an acute angle bend for hemming applications . That acute angle is then positioned under the clamping tool foot to close the hem to a specific height . This height can be selected for parallel hems , teardrop hems or even open hems used in assembly .
On up-down acting machines , the folding beam moves upwards or downwards , depending upon the bending direction
Tapered bending ( THALMANN ).
76 | sheetmetalplus . com | ISMR October 2021