Laser die-cutting of labels – advantages of the technology

Laser die-cutting is a technology of cutting and cutting materials using a high power laser. It is the most modern and precise technology for die-cutting labels and making grooves in punching forms.

For laser cutting and engraving in printing production, C02 gas lasers operating in pulse mode are used.

Label material paper cutting.

Cutting paper with a laser is accomplished by a laser beam that cuts thermally. The focused laser beam, controlled by a computer, provides a high concentration of energy and allows almost any material to be cut, regardless of its thermophysical properties. In the laser die-cutting process, the material is ignited and vaporized under the influence of the laser beam.

1. radiation generator (laser);
2. mirror system;
3. mobile work table;
4. beam coming from the radiation generator through the mirror system to the cutting head;
5. horizontal motion system of the cutting head;
6. vertical motion system of the cutting head;
7. cutter head housing with an optical channel for the laser beam;
8. material sheet to be die-cut; X, Y – cutting head motion directions; Z – mobile table motion direction

Laser systems allow to perform various operations: die cutting, grooving, perforating etc.

Cutting of paper or printed labels by laser beams is quick (up to 90 mm/s) and accurate (laser beam is positioned with an accuracy of up to 0,001 mm), according to the vector program. When using a laser machine to cut cardboard, the thickness of the cutting line is 0.01 mm.

Narrow cuts with a minimal heat-affected zone are possible. Laser cutting is characterized by absence of mechanical impact on the processed material, there are minimal deformations, both temporary in the process of cutting, and residual after complete cooling. Consequently, even easily deformable and non-rigid workpieces can be cut by laser with a high degree of accuracy. The high output power of the laser light guarantees high productivity combined with a high quality of the cut surfaces. Easy and relatively easy control of the laser beam allows you to perform laser cutting along a complex contour of flat and volumetric parts and blanks with a high degree of process automation.

Printed labels are soft materials and this cutting technology is ideal for them: the sheet does not crumple or tear during cutting. It is not even necessary to fix the material on the table: there is no displacement due to the absence of physical contact.

When cutting paper or cardboard it is important to keep in mind that cutting should be done in one layer, otherwise combustion products accumulate between the sheets and the material becomes dirty.

A significant advantage of a CNC laser machine is the ability to accurately cut corners (including sharp corners) – without distortion, rounding, breaks, etc. The main advantage, however, is the high versatility of automatic CNC machines. Thanks to easy programming, the laser machine can be quickly reconfigured to produce a different type of product. In this case, the production cost remains low – regardless of the volume of print runs, and the quality of individual blanks and their complete identity always corresponds to the factory accuracy specifications of the equipment.

The denser the label paper and the thicker the workpiece, the higher the laser power must be activated to achieve an acceptable processing capacity. However, the higher the laser power, the greater the risk of burning the edge of the seam. And “burning” the cardboard does not so much spoil the label material itself as it covers the cutting area with a thin layer of soot, which can be difficult to remove. In addition, this soot can smear the rest of the cardboard surface.

To solve this problem you should:

• First, adjust the processing modes, i.e., set the optimum ratio of laser power to the speed of the transmitter. However, there are no unambiguous recommendations for this – the optimum processing parameters are determined experimentally, in specific production conditions;
• Secondly, to place a cardboard blank (to avoid edge burning) on the honeycomb worktable and be sure to provide for air blowing. It is better to cut cardboard from the underside – then a slight blackness may not affect the overall quality of the product.

For light-colored paper black fouling from the edges of the cut is particularly unpleasant. One time-consuming but effective way to combat fouling is to seal the surface with a laminating film and cut the cardboard through this “film protection”. The film is removed along with the fouling and the surface of the paper is perfectly clean.

If, on the other hand, both sides of the paper blank are sealed with film and the cutting modes are selected so that the lower layer of the film is not cut through by the laser, then small elements of the cut are easily separated when removing the film, which significantly saves time for manually “piercing” the processing points (for example, when cutting fonts).

However, such a “film” way of protecting against fouling is not suitable for every type of cardboard. For example, “loose” paper can be difficult to peel from the film, even though the laminating film is moderately adhesive.

Advantages of laser cutting. Among the many advantages of laser cutting are such as:

• Fully automated process;
• High-quality, clean cut, even when using thick materials; perfectly smooth cut – no jaggies, burrs, smooth cutting line regardless of the complexity of the contour;
• Ability to cut very complex contours, including small dimensions;
• No destruction of input edges, unlike other technologies;
• No need to make templates, as modeling is performed on the computer using vector layouts;
• High cutting speed in comparison with mechanical methods;
• Possibility to produce miniature packages;
• Much more opportunities for decoration than traditional cutting methods;
• Low cost of production of single copies, for example, industrial samples (in comparison with the cost of die-cutting).

Laser die-cutting equipment

Laser cutting device is a rather complicated and expensive equipment. Besides the laser light source it includes a coordinate table and CNC (Computer numerical Controlled Program) control system.

If you are interested in producing labels for your products using laser die-cutting technology, you can always turn to us for help. We also offer a look at laser cutting machines here.