How to avoid plate bending indentation during bending

Press brake machine is one of the commonly sheet metal equipment. However, during the bending process, affected by the mold, bending pressure and other factors, the folded plate often produces bending indentation.

Especially aluminum and stainless steel plates. These bending indentation will seriously affect the appearance of the product.

In order to avoid or reduce these bending indentations, many manufacturers will choose to perform secondary processing, grinding again after bending or painting the board.

Some manufacturers will coat the sheet before bending to avoid bending indentation. However, these operations are not only time-consuming and labor-intensive, but also have little effect.

Causes of bending indentation

Most press brake machine use V-shaped molds, the left picture is before bending, the right picture is in bending

Points A and B are the stress points of the plate, and creases usually appear at points A and B.

When bending, the upper die falls, and the plate slides along two points A and B. L is the sliding range and is also the place where bending indentation is most likely to occur.

If the manufacturer adopts a coating method to avoid bending indentation, the protective film is easy to break as the bending pressure changes. Once the protective film is broken, bending indentation will occur.

Solution

Roller type V mold

The main working principle of this kind of mold is that the upper mold falls, the rotating shaft rotates, and the flip plate is turned over. It is precisely because of the turning of the turning plate that the workpiece is in full contact with the lower mold, without any sliding range, to avoid bending indentation.

Replaceable rubber strip V mold

The principle of the mold is to open a gap on both sides of the common V-shaped mold, and insert a rubber strip in this gap. During the bending process, the sheet is in contact with the rubber strip. The hardness of the rubber strip is much lower than the ordinary lower mold, so as to avoid bending indentation.