One of the most important technological operations in of manufacturing metal products is the bending of sheet metal with Using bending equipment. As a rule, after bending the metal on its surface there are traces (scratches) from the working elements of the bending press – dies and punches.
With conventional bending, it is impossible to avoid side effects such as:
- scratched product surfaces;
- deformation of holes caught in the bending area;
- stretched (twisted) edges of the product if during bending the edges of the part are not perpendicular to the bending tool;
- not always high bending accuracy.
But what about when the customer’s requirements for the product, The customer’s requirements for the product include high bending accuracy and exclude bending marks? bending?
How to bend parts without marks
There are several technological solutions to ensure bending of metal products without traces (scratches) from the dies. In particular, is bending with the use of:
- special film and standard matrices;
- polymer inserts on standard matrices;
- rotabend matrices with rotating inserts;
- matrices with polyurethane inserts – for bending radii.
Consider in more detail the above bending methods.
Bending with the use of protective film
Film bending involves placing a protective film over the entire working surface of standard dies using special holders. This method is the cheapest, but it shows excellent results. Namely:
- prevents bending marks;
- is optimal for bending products made of aluminum, stainless steel, painted metal;
- does not require any further rework of the parts;
- is easy enough to use;
- can be used on any standard matrix.
Bending with polymer inserts
Bending with polymer inserts involves the use of special composite inserts on standard matrices. Technologically is a more expensive way of bending, because for each die die, a separate insert has to be selected. At the same time, the main advantage of this type of bending is a high accuracy of bends and, of course The main advantage of this type of bending is a high precision of bends, of course, the absence of scratches on the metal surfaces.
Bending without traces with Rotabend dies
The most expensive, but at the same time the most technologically advanced and high-quality bending process is bending with the use of Rotabend dies with rotating inserts (TRUMPF, UKB, WILA) in the base of the die arm. These dies have two spring-loaded moving hemispheres that are installed on top of the die body. During bending, a sheet of metal is placed on the flat surface of the hemispheres, and then, when lowering the punch, the hemispheres are rotated, repeating the movements of the workpiece. Moving hemispheres of matrixes thus support the sheet on a large contact area, in contrast to conventional V-matrixes, when during bending the product is in contact with two points on the edges of the shoulder of the matrix. The main advantage of this scratch-free bending method is the possibility to obtain a minimum shelf of the sheet, as well as the absence of deformation when bending a perforated metal sheet.
Radius bending without marks
In case it is necessary to bend a part with a certain radius, the most effective method is the use of dies. The most effective method is the use of dies with polyurethane inserts. polyurethane inserts. This technology makes it possible to obtain radius bending of metal with observance of any parameters of the radius or angle.
As we can see, each of these methods has its own advantages, but they have The one thing that unites them is the absence of bending marks (scratches) on the products.
LLC “Gromov” performs sheet metal bending without traces of matrixes (without scratches).