Film-laminated metal materials are very common, such as metal doors and windows, elevators, etc. In order to maintain the surface smoothness and integrity, metal materials are usually laminated with films to avoid scratches during transport.

Some people may ask, can a fiber laser cutting machine cut film laminated metal sheet?
The answer is yes, but there are certain difficulties at the same time.

Difficulties

1. Since the fiber laser has a relatively short wavelength, only 1.06um, it is difficult to be absorbed by non-metallic materials. When cutting film-laminated stainless steel, slags, incomplete cutting, high reflection alarm phenomena frequently occur, which has a great impact on cutting quality and normal production.
2. In order to melt the surface film, it is necessary to utilize the reflected heat of the laser on the metal plates. If the power is too low, the film cannot be cut through; if the power is too high, the surface of the plate is easily damaged.
3. A single cut of the laminated metal is very unstable, and the surface film is easily blown up.

So how do we cut film-laminated metal sheet with fiber laser cutting machine?
Since the film-laminated metal sheets are further divided into single-sided film-laminated metal sheets and double-sided film-laminated metal sheets. We will discuss the film-laminated metal sheet cutting respectively.

Single-sided Film laminated Metal Sheet Cutting

When cutting single-sided film-laminated metal sheets, such as the brushed or mirrored stainless steel, in order to avoid film damaging, the side with the film is usually cut with facing upward, and the side without the film is facing downward. Because of the side of the film is facing down, the residue splashed by the laser cutter may stick to the film due to thermal influence, which will make the film surface rough. Meanwhile, it is difficult to cool down the film after cutting and to remove the dross attached to it. Therefore, it is recommended to cut the surface with the film first.

Here is solution:

Lower the power and keep the distance between the laser head and surface of the material at about 10 mm. Then, burn the protective film in the cutting path, and perform cutting afterward.
Note: It is better to install a pneumatic device on the backside of the metal sheet to avoid scratches by the sharpen sawtooth support worktable.

Double-sided Film laminated Metal Sheet Cutting

We know that the fiber laser cutting head can only perform cutting from the top to bottom. Although the laser will have no big effect on the protective film on the top surface of metal sheet during the cutting process, the cutting residues generated during the cutting process may not fall down due to the laminated film on the back of the sheet. These residues will directly affect the cutting effect of the sheet, resulting in incomplete cutting of sheet or generation of large burrs after cutting. However, if the protective film under the sheet is completely torn off, the back of the sheet is easily scratched.

Here is solution:

The protective film on the bottom of the sheet does not affect the cutting quality. Only the protective film on the bottom of the cutting position affects the cutting quality. So, it is only necessary to remove the protective film on the bottom surface of the sheet cutting position.
Therefore, for double-sided cutting, we can use the function of laser etching. First, find out the actual cutting position on the sheet, then tear off the protective film at the cutting position, turn the sheet over, and perform the cutting.