Products > BENDING SOLUTIONS > Mark Free Bending

Mark Free Bending

Marke free bending solutions in comparison

During the bending process it's really difficult to avoid marks, such as scratches and abrasions, on the sheet metal. This problem is occuring especially when bending stainles steel, aluminium and painted sheet metal.
Marks often appears on contact points between the die and the sheet metal, compromising the aesthetics of the product. That is a direct consequences of the friction between the sheetmetal and a die  V radius which is too small.

ROLL PRIME

ROLFILM AND TENSIONER

POLYURETHANE INSERTS

NYLON DIES INSERTS

Rolleri’s constant research for innovation brought us towards the 3D printing world, the future of manufacturing. Roll Prime is the solution for applications which require mark-free sheet metal,reduced delivery time and dimensional precision: thanks to FDM technology (Fused Deposition Modelling) we are able to produce tools and inserts made of special plastic material, completely adaptable to customer’s needs with halved production lead time compared to traditional technology.

The solutions proposed are totally customizable, so it is possible to design inserts that completely match the tools already in your possession. The full freedom of obtainable geometries allows us to study customised solutions for each customer, also offering the possibility of rapid prototyping.

One of the most common ways to avoid sheet metal marks during bending is the use of ROLFILM. Rolfilm is a foil available with different thickness, which is positioned between sheet metal and die.
The choice of one rolfilm thickness or the other depends on the sheet metal thickness to be bent. 
By shifting Rolfilm along X axis, you can use its whole surface; if for example you use a V20 die, you have at least 15-20 bending positions in the same film portion before moving the foil forward. Rolfilm rolls are available of 3m, 10m, 20m and 30m. Thanks to this possibility you can buy the length you need.

A very useful accessory to use the whole Rolfilm width is CT, a pair of tensioners. Each tensioner is mounted at one end of dies with a clamp tightened to die stem. In the upper part of CT you can insert Rolfilm.
Both tensioners mounted opposite to each other are fundamental to set the proper foil tension for correct use.
ROLFILM has very good elastic and compression properties. For this reason CNC setup correction needed are limited.
In order to improve foil operational life by bending on the same foil portion, you can use Rolfilm with dies with bigger radius (for example T dies CLASSIC - TR dies).

Polyurethane inserts and their holders have been designed to give a good quality solution when bending large-radii.Such solution provides two important advantages: mark-free profile and precise radius.A polyurethane insert can be compressed in the middle during bending and can wrap sheet metal around a radius tool.Actually it works like a die deforming according to punch radius.Please notice that the maximum sheet metal thickness to be used for this application is 2mm.

Rolleri offers different polyurethane inserts with different dimensions according to the needed radius.As far as profile angle is concerned, we can offer full inserts (for wider profile angle) or inserts with a hole, which can undergo bigger compression and can bend narrower angles.Holders have to limit polyurethane insert deformations, so that its deformation happens only according to punch radius.Each insert has its own holder, so that deformations are guided.The last element to take into consideration is PSTCON: a pair of plates to close inserts at both ends to avoid uncontrolled deformations in this areas.

A solution to avoid sheet metal marks is the use of nylon inserts and their holders.

These nylon inserts have a V opening in the middle similar to standard dies V opening. The main difference is the material, which in this case is nylon in order to reduce sheet metal friction while sliding into the V opening. In this case the surface contact is soft and therefore it doesn't scratch sheet metal.

Each insert is available with V opening ranging from 6mm to 16mm (0.24'' to 0.63'') and according to the bending angle you can choose angle 88°, 60°, 45° and 30°. Inserts are always positioned in precise holders, so that they have no space to move freely.

On holder operator's side there are fixing screws to clamp inserts properly.

Insert outside dimensions are 14mm, 20mm, 30mm (0.55', 0.79'', 1.18'') and they have been studied in order to bear the necessary tonnage according to the sheet metal to be bent.

Such a solution is recommended to bend profiles with bends and counterbends, as you can use die stem for the negative bend.

In order to set press brake CNC up, we supply dxf drawing like for conventional tooling. Press brake operator should control bending angle frequently and set corrections caused by slight wear of insert radius, especially when insert is new.

ROLL PRIME 20.17

Rolleri’s constant research for innovation brought us towards the 3D printing world, the future of manufacturing. Roll Prime is the solution for applications which require mark-free sheet metal,reduced delivery time and dimensional precision: thanks to FDM technology (Fused Deposition Modelling) we are able to produce tools and inserts made of spec…

RolFilm and Tensioner

Protective foil built with different thicknesses, to place between the die and the sheet metal.

on stock