Over the years, different types of lasers have established themselves thanks to their versatility. Apart from technical differences in construction, the particularity of each laser lies in the propagation medium used to emit energy and the resulting wavelength.

The most common are gas lasers (such as the CO2 laser), semiconductor lasers, fibre optic lasers and solid-state lasers. Depending on the medium used, the laser generates a beam at a different wavelength. The lasers manufactured so far cover the entire electromagnetic spectrum.

Why the laser wavelength is key

The wavelength is crucial in determining the possible uses of a laser. From it depends the kind of interactions between the laser and the material. Each material responds differently to a certain wavelength. Some materials, like acrylic, can absorb in the near IR or be transparent in the far IR. The optimum balance is achieved when most of the energy generated by the laser is absorbed by the material, allowing efficient processing.

Based on what we have said, it is impossible to establish an optimal wavelength. The choice depends on the characteristics of the material to be processed.

However, it is possible to give general indications. It has been demonstrated that some lasers have a wavelength which makes them suitable for a wide range of applications.

The wavelength of CO2 laser

The CO2 laser in particular has a wavelength of 10.6 micrometres, which is in the far-infrared region. This length is absorbed very well by all materials containing carbon. Wood, paper, plastic polymers, organic materials, natural and synthetic fabrics respond perfectly to CO2 laser radiation.

What’s your need?

Certainly, of all lasers, the carbon dioxide laser has proved to have the greatest versatility and has therefore established itself as the main choice for the laser processing of materials. Contact us for more information!

The CO2 laser has been on the market for many decades. Over the years it has proven to be a sturdy tool, capable of providing thousands of hours of processing without having to be serviced or replaced.

Unlike for mechanical production equipment, one of the biggest advantages of laser processing is low maintenance.

Mechanical tools operate by contact between parts and rely on moving mechanisms. The friction generated during machine operation makes wear and tear on this production equipment a pressing problem. Periodically, production has to be stopped in order to carry out the necessary maintenance operations, which increases the costs of operation and processing. The die sector is but one example of an industrial process that suffers from this problem. In this type of application, the dies have to be replaced periodically to guarantee the quality of the cut.

Laser, on the other hand, is a non-contact process. The entire laser system is based on the production and transmission of electronic pulses and the generation of polarised light beams. There are no moving parts or friction and therefore no direct impact on the lifetime of the laser source.

However, this does not mean that laser sources are maintenance-free. Laser sources also wear out, albeit much more slowly. This is why they need regular maintenance.

In the case of CO2 laser sources, the main problem is the rarefaction of the gas inside the laser tube. Year after year, the gas mixture is normally depleted, resulting in around a 1-2% emitted power decrease per year. This causes a gradual deterioration of the processing and a consequent decrease in efficiency.

The only solution to this problem is to periodically regenerate the laser source. However, this is a costly and time-consuming operation that usually involves stopping the production line, resulting in a negative impact on productivity.

El.En. has created a series of laser sources based on Self-Refilling technology to overcome this very problem. These sources, called Never Ending Power, avoid the regeneration of the source thanks to the use of a cylinder that contains the propagation medium. This cylinder can easily be replaced without causing any delays and guarantees the same process parameters and power over time.

This innovative recharging technology now makes it possible to have a laser source that always functions at maximum power. The laser beam’s quality will consistently remain at its highest level and the lifespan of the laser source will practically be infinite. Contact us for more information!

Laser cleaning is the process of using lasers to remove dirt, debris or contaminants from the surface of an object. It is a process that lends itself to a variety of industrial and non-industrial applications. From cleaning thermoforming moulds to restoring monuments, there is no area where laser cleaning cannot be successfully applied.

In this article, we explain what the laser cleaning process consists of, the principle on which it is based and why it has an advantage over conventional cleaning methods.

Conventional cleaning methods

In the field of industrial production, the maintenance of production tools is essential, particularly in those areas where the quality of production depends on it. In the plastic thermoforming sector, for example, it is essential to always have clean moulds in order to obtain high quality parts. Rust, dust and material residues are among the most common types of dirt that need to be periodically removed.

However, cleaning operations are very costly in terms of resources. The actual performance depends on the type of maintenance required. But in general we can say that cleaning methods are based on the use of chemical or mechanical methods.

In the first case, cleaning is entrusted to solvents, detergents or other chemical compounds that degrade the material to be removed and facilitate its removal. In the second case, systems such as sandblasting or ultrasonic cleaning are used.

These cleaning methods have major disadvantages. They are very polluting because of their use of chemical products and require operators to take special safety precautions.

In addition, physical contact often causes damage to the workpiece which, in the long run, ends up being damaged by the cleaning operations.

Laser cleaning has established itself precisely because it has the advantage of overcoming the main drawbacks of traditional cleaning methods.

Laser cleaning and its advantages

Laser cleaning consists of irradiating the surface of a material in such a way as to remove the surface layer. The technique is based on ablation. The beam concentrated on the material breaks the molecular bonds of the material that needs to be removed. The material evaporates instantaneously with virtually no residue left behind.

Unlike conventional methods, there are no solvents or other additional chemical substances used in laser cleaning, and since it is a non-contact process, there is no abrasion that could damage the workpiece, as the surface dirt is removed without attacking the underlying material.

It is precisely this protection of the material that makes the laser so attractive. The laser allows you to operate selectively on a given material. The laser only removes materials that are absorbed by its wavelength. In addition, each material has different properties and needs a different amount of energy to be removed. This makes it possible to work on materials very precisely, to calibrate the laser extremely selectively so as not to damage the underlying material.

Flexibility, high controllability of the medium and speed are the characteristics that make laser cleaning an extremely effective tool.

Laser cleaning is one of laser’s many applications. The process is based on laser ablation, i.e. the removal of a portion of material from a surface. Ablation is at the basis of all common laser processes: cutting, drilling, engraving, marking.

While the purpose of these processes is to create cuts, holes or marks in the material, the aim of laser cleaning is to remove dirt particles from a given surface.

Laser cleaning of industrial moulds

The production process of thermoplastics is an example of an industrial laser cleaning application. The main production method for these materials is moulding. At the end of the production process, the moulds need to be restored to their original state. This step is crucial because the quality of the final part depends on it. The presence of material residues, or other debris, affects the final quality of the parts.

Traditionally, the cleaning process is carried out using one of three techniques: dry ice blasting, ultrasonic cleaning or manual cleaning. Each has both advantages and disadvantages.

Dry ice cleaning consists of directing a high pressure jet of dry ice onto the mould. The ice penetrates the mould cavities and removes residues. The operation is carried out by an operator who directs the jet onto the areas that need to be cleaned. The advantage of this technique is that it can be used directly in the production line. However, it is not an environmentally friendly method since it requires the use of large quantities of dry ice.

For ultrasonic cleaning, the mould is placed in special ultrasonic cleaning machines. In practice, this involves disassembling the part and immersing it in special tanks filled with solvent and water. In addition to the need to disassemble the mould, this method has the disadvantage of using polluting chemicals.

Manual cleaning consists of cleaning the moulds using a solvent and manual force. It is a slow and inefficient method.

Laser cleaning overcomes these disadvantages.

Firstly, it can be performed selectively: the laser only acts on materials that are compatible with its wavelength. Laser cleaning can therefore be used in sensitive applications where abrasion-based procedures such as sandblasting would be too invasive.

The absence of waste also makes it an environmentally friendly technique. Laser cleaning doesn’t use solvents or other chemicals, doesn’t produce any waste and also doesn’t consume water or other resources. It is a thermodynamically efficient process. The laser vaporises the material by sublimation which makes it an environmentally friendly process.

Finally, laser cleaning is extremely precise. The process is completely digitally controlled which makes it possible to work on extremely small surfaces or follow extremely complex cleaning patterns. Unlike with traditional methods, it can clean hard-to-reach spaces and uneven surfaces.

A system tailored to your application

Laser cleaning is a versatile application. It is efficient, adaptable, precise and most importantly, ecological. El.En. is the ideal partner to create a tailor-made application for your production process. Contact us and we will be happy to help you find the best solution for your needs!

The manufacturing process of abrasive materials has always been a productive challenge. The main problem is that the abrasive power of these materials also exerts itself on the production tools themselves, damaging them over a short period of time.

This results in very high maintenance costs for the tools. In addition, the fact that using precision tools is difficult makes it impossible to carry out precise machining on these materials.

The introduction of laser technology was therefore a major innovation, as it made it easier and cheaper to manufacture abrasive tools and materials:

• Laser production processes are contactless. In laser processing, no mechanical forces are involved, unlike in traditional manufacturing processes. The interaction between the laser beam and the material produces a high energy density that removes a certain amount of material.
• Laser technology enables a high degree of control over the production process. What does that mean? It is possible to set up the laser parameters, down to the smallest detail, in order to minimise the difference between the desired result and the result obtained. In other words, you can create a material with characteristics that are perfectly suited to its intended use.

Diamond abrasives

A few decades ago, diamond abrasives joined the ranks of traditional abrasives. These tools exploit diamond’s exceptional hardness and thermal conductivity to achieve excellent abrasive performance.

Diamond is one of the hardest materials known to man. It also has excellent strength, good wear resistance and a low friction coefficient.

Diamond tools can be used in a wide range of applications:

• geological prospecting
• stone processing
• construction
• woodworking
• tooling
• ceramic processing

Diamond tools can be manufactured in various ways. Generally, synthetic diamonds are used, or diamonds judged to be of unsuitable quality for jewellery making.

To make tools, diamonds are combined with another bonding material so that, for example, tools can be made from metal, resin, ceramics, etc.

They can also be used for a wide range of purposes, including all traditional mechanical operations. These include cutting, drilling and, among other things, abrasive tools.

The manufacturing process for diamond abrasive tools comes with the same difficulties encountered in the production of conventional abrasive tools. However, it also has an added difficulty: the hardness of the diamond subjects the production equipment to even greater stress.

Here too, the CO₂ laser can be an advantageous solution.

Diamond abrasives can be subjected to laser ablation processes using a continuous wave laser. This technique can create textures and other passive layer characteristics that enhance the performance of the material.

The process is especially effective on resin bonded abrasive materials. Resins and plastics in general absorb CO₂ laser radiation very well and, therefore work very effectively for laser ablation processes.

A new application for the CO₂ laser

Diamond is one of the hardest materials in existence, which makes the efficient production of these tools difficult and limits their widespread use. On the other hand, however, diamond abrasive tools offer enormous advantages and are crucial in certain applications. The introduction of laser machining processes has made their production more efficient and cost-effective, paving the way for their widespread use. Research in the field is still ongoing, bringing with it other possible applications in the future.

El.En. has been producing CO₂ lasers for various industrial sectors for over 35 years. Experimentation, research and development in the field of lasers applied to materials is in our DNA. If you are thinking of making an application of this type, contact us and we will be happy to study the ideal solution for your needs.