Today we are talking about one of the most widespread industrial applications in the field of laser technology: laser microperforation. You may not have realized it, but many of the objects that we regularly use are micro-perforated to make life a little more comfortable, later you will see some examples that will surprise you.
The applications of Laser Microperforation do not stop increasing day by day, and with the constant improvement of the equipment and the technique, it is expected that this trend will continue to be maintained during the coming years.
Next, we explain in more detail what it is, the types that exist, its applications and its benefits.
What is it?
Laser Microperforation consists of making very small through holes in various sheets, films, sheets or plates, using the energy provided by a laser source as a perforation method. These holes can be as small as 5 microns in diameter, but the current limit for industrial applications is usually at diameters of 50 microns, equivalent to the average thickness of a human hair.
Human hair Diameter 50 microns
High density plastic film with 50 micron microperforations
Laser technology, as we have already commented on other occasions, with applications for cleaning, marking, or mold microstructuring, is based on the accumulation of light focused on a very small point of space. This accumulation of energy is so great that it can vaporize materials such as polymers, metals and even ceramics, and at the same time it is done in such a controlled way and in such a small point that it allows microperforations of very good dimensional quality to be made without affecting the negative way to the surrounding material.
Types of Laser Microperforation
Although we have explained what laser microperforation is, it must be pointed out that not all laser microperforations are the same. The technique used will vary depending on the diameter of the hole, the thickness of the layer to be drilled, the material and the geometry of the hole that we want. The most common types of microperforation are the following:
When the thickness of the layer to be perforated is low, a laser with adequate power and spot diameter can be used to get through the material in a single laser pulse. In this way, drilling with the desired characteristics is obtained, obtaining high productivity and drilling speed.
When the thickness of the layer is high, the material absorbs little energy, or the laser does not have enough power to be able to perforate the layer in a single pulse, percussion is used. This method consists of launching several pulses at the same point to gradually remove material from the surface until it is perforated.
This method is indicated for large microperforations, larger than the diameter of the laser spot itself. In these cases, the diameter of the hole is covered by moving the laser beam in order to perforate it. Simply put, it would be like trying to cut out a circle with an awl, making lots of holes. This is the technique also used for conventional laser cutting.
It must be said that all these techniques affect how the microperforation is processed, but they do not affect the internal geometry of the holes, which are conical by themselves. In fact, this is because the laser is focused on a point in space, but as it moves away from that point, the beam increases in diameter. Due to this phenomenon, the incident face of the laser usually has a larger hole diameter than the back face. For most applications this difference is not relevant, but for applications where this is an important factor, specialized optical equipment can be used to lengthen the focal point to achieve cylindrical rather than conical holes.
Laser Microperforation Applications
The applications of this type of technique are very varied and cover almost all sectors, from the typically most industrial ones such as the automotive industry or aeronautics, to health and food, including consumer goods and defense.
Below, we explain some specific examples of applications that are used depending on the type of material:
- Polymers: The use of laser microperforation in plastic films in the packaging sector to make easy-opening is widely extended, while, in the food sector, it is used to prolong the life of perishable products such as fruits and vegetables, generating controlled atmospheres. . One of the less widespread applications, however, is the microperforation of rigid plastic, which can be used to make invisible points of light that become visible when a light is passed through them. You can see in this Project that we carry out, an application to provide gaseous permeability to a film without liquids or solids passing through.
Rigid microperforated plastic piece
Food microperforated controlled atmosphere
Microperforated plastic film
- Metal: the main applications in the most industrial sectors have been to make injectors for turbines or automobiles, and in the health sector, to manufacture medical equipment, where great precision and very small dimensions are required. However, there are many applications, such as our Project to replace conventional machining using a press.
Microperforated sheet metal
Microperforated stainless steel plate
Laser Microperforation has multiple advantages, but here we summarize some of them:
- Minimum hole size, only achievable with this technique, due to the different optical configurations available.
- It does not need consumables and is respectful with the environment, as it does not generate waste.
- Ability to pierce any material if the right laser is chosen.
- Possibility of making very close holes with great precision without collapsing the surrounding material.
- Fast drilling speed, suitable depending on the application for online processes without the need to stop the parts.
How to carry out a Laser Microperforation Project?
First of all, we must define the diameter and the separation of the microperforations that we need for our application, whether it is to allow light or gas to pass through. Depending on this diameter and the material of the substrate, the type of laser, power and the necessary optics will be selected. Once selected, it is necessary to perform an optimization of the laser parameters (power, pulse, frequency, separation, etc.). It is highly recommended to carry out a scanning electron microscopy (SEM) inspection of the result to verify the quality of the microperforations.
Do you want to apply Laser Microperforation in any of your Projects? Contact us!
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