Laser marking is one of the most widely used laser processes in the industrial sector. It is typically used to apply information to packaging: expiry dates, traceability codes, production batches, logos and other graphics. The fundamental advantages of laser marking over traditional methods are the very high processing speeds and the high levels of precision that can be achieved.

But the advantages don’t stop there. Laser technology not only allows manufacturers to increase processing efficiency parameters, but also to perform types of processing that would be impossible to do with traditional methods.

How does laser marking work?

Laser marking is a processing technique in which a laser is used to produce an engraving on the surface of a product. As with all laser-based processes, this technique exploits the laser’s ability to concentrate large amounts of energy on one spot with a diameter of a tenth of a millimetre. At the site where the laser touches the material, very high energy densities are reached, which cause the temperature to rise within a few seconds, triggering physical and chemical transformations.

A key feature of laser processing is the high degree of control. It is possible to decide with great precision how deep the laser’s action should go. With laser marking, the mark is only produced superficially, on a layer that goes from a few microns to one or two millimetres. Past this depth, one no longer speaks of laser marking but of laser engraving. The two processes, although similar, differ in the depth of the laser marking which in turn changes its perception. Laser engraving creates marks that are more visible and perceptible to the touch. In laser engraving, the mark is visible but not very perceptible to the touch.

Laser marking and packaging

In all laser processing, the type of power used depends on two factors: the material one wants to process and the speed one wants to reach. As you may already know, every laser emits a beam of polarised light at a defined wavelength. Some materials absorb certain wavelengths well but not others. In the packaging sector, the CO2 laser is the one that gives the best results. Its 10.6 micrometer wavelength belongs to the far infrared region which is very well absorbed by the organic materials most frequently used for packaging (e.i: paper, cardboard, thermoplastic polymers, glass).

Advantages of laser marking

Traditionally, the following methods are used to mark information on packaging:

1. inkjet printing
2. thermal transfer printing
3. stamping
4. hot stamping
5. mechanical engraving

These techniques are always based on contact between the tool and the workpiece. Compared to them, the laser has several advantages:

1. reduced cost: the information is engraved directly on the product, which eliminates the need for any other material, such as ink and labels
2. indelibility: it is resistant to wear, solvents, scratches, light and counterfeiting attempts.
3. automation: the process is fully automatable.
4. flexibility: laser marking can imprint any type of information, however complex.
5. contact-free: materials are not subjected to mechanical stress.

Materials and laser marking

As mentioned above, the characteristics of the material used influence the specific characteristics of the marking operation.

Paper and cardboard packaging

Paper and cardboard are made from cellulose, a material of organic origin produced through wood processing. The laser acts on the paper by vaporising a thin layer of material. The resulting mark has the same light colour as the material and may therefore offer little contrast. The contrast can be increased by adding a dark-coloured overlay. In this case the laser only removes the coloured surface layer to reveal the light part underneath. The contrast between the white of the paper and the darker colour of the surrounding layer creates a very legible mark.

Laser marking on plastics

Plastic is a synthetic organic product based on carbon-based polymers. On certain types of plastic, the CO2 laser is very efficient and gives optimum results. The plastics that are best suited for laser marking are those most commonly used in the packaging industry, such as polyethylene, PET or polypropylene. Polypropylene is also suitable for laser cutting.

Laser marking on plastics is carried out by chemical transformation (the laser breaks polymer chains). The fact that the light affects the mark differently to the surrounding material makes it quite visible. Depending on the additives applied to the plastic, different levels of contrast can be achieved.

Laser marking on glass

Laser marking can also work with glass. Marking on glass is carried out through the physical transformation of the material. Glass is a very fragile and inflexible material that traps micro-bubbles of air inside itself. When the laser strikes the surface of the material, the air bubbles expand due to the heat, creating micro-fractures. This changes the transparency of the material and creates the mark.

Beyond packaging

In some cases, laser marking can eliminate packaging. In recent years, laser marking on food has become a well-established technique. It is mainly used on produce or cured meat and cheese but can be used on any compatible product. In this application, the marking is done directly on the surface of the product. A layer, a few microns deep, is removed from the surface. The laser beam does not penetrate into the product so its freshness is preserved. Several studies have shown that laser marking does not affect the quality of the product in any way. Food distributors rely on it to save on tons of packaging materials each year, including self-adhesive labels.

Equipment for laser marking in packaging

The technical requirements for a laser marking system are a CO2 laser source, which produces the beam, a scanning head, which moves the beam over a surface, and a software controller, which coordinates the system.

The laser source

In the El.En. catalogue we have laser sources that range from 60W to 1200W of power. Greater power corresponds to greater energy per unit area, which can be translated into greater execution speed. Our catalogue has a selection of laser sources optimised for certain packaging materials. BLADE RF177G and BLADE RF333P with their two different wavelengths of 9.3 um and 10.2 um are perfect for the materials used in the packaging industry and in kiss cutting for adhesive labels.

Our Never Ending Power sources use Self-Refilling technology that potentially makes the laser’s life endless. This involves the addition of a consumable, the gas cartridge, which contains the propagation medium and can be easily replaced when it runs out. In this way, sources can maintain their performance over time. Unlike sealed lasers, this eliminates the time-consuming and costly refurbishment process.

The scanning head

Applications such as marking are called galvo laser scanning because they use galvanometric mirrors to move the laser beam across the surface.

The main feature of our scanning heads is that they have a z-dynamic motor, which allows the focus to be adjusted in height and thus maintain constant parameters on the work area.

The digital controller

The CO2 laser source and the scanning head need software to coordinate their movements in order to perform the required machining. Our heads also include this control system, which can be easily integrated with common operating systems.

Contact El.En.

Laser marking is one of our areas of expertise. Our engineers have worked on dozens of laser marking application projects in this field. If you work in packaging and are interested in a laser solution, contact us and we will be happy to find the best solution for your needs.

In recent decades, lasers have become a widely used processing tool. Its role as a production tool is increasingly established, both in traditional applications such as laser cutting, laser welding or laser marking, and in more advanced ones such as laser paint removal, laser surface treatment or laser microperforation.

The success of this tool is due to the advantages it offers in terms of process flexibility. The same laser source can be used to perform different processes such as cutting and marking on different materials such as plastic and wood, even within the same operating cycle.

This great flexibility translates into process complexity. In general the working mechanism of the laser is very simple. A laser is a light source capable of concentrating a very high energy density, so much so that it can be used as a heat source. In practice yet, the interaction between the laser and the material is influenced by numerous factors that make it very complex.

Conceptually, cutting, drilling, engraving and marking share the same processing mechanism: laser energy is used to create chemical and physical transformations in the material. These transformations can range from the simple colouring of the material, as is the case with laser marking, to the complete removal of the material by sublimation as is the case with laser cutting. In order to switch from one process to another, it is sufficient to modify the laser parameters using the appropriate control software.

For this reason, each application must be studied according to the characteristics, of the laser, of the process and of the material.

In this article we will analyse the main parameters that come into play in laser processing, with particular reference to the CO2 laser.

Laser-related parameters

Unlike traditional production tools, laser technology has a wide range of configuration options. Each parameter affects the end result of the process and must therefore be configured appropriately according to the desired result on the material.

The laser parameters to pay attention to are:

• laser source power
• beam spatial mode
• beam temporal mode
• laser wavelength
• beam polarisation

Laser source power

The power of the laser source is a very important parameter. It regulates the laser’s processing speed and the depth of the engraving. The more powerful the laser, the greater the amount of processed material in the same amount of time. Furthermore, the more powerful the laser, the thicker the material that the laser will cut can be,although, as we will see further on, this parameter depends in part on the characteristics of the material.

If you are using a low-power laser, it may not be possible to cut a material from side to side. On the other hand, a laser with a higher power than the one needed to carry out a specific process, can cut through the material, with the risk of obtaining a lower quality cut, with burnt and uneven edges due to the slag produced by the excessive power of the laser.

As a general rule, the choice of the power of a laser source should be made in excess so that the power can be lowered until the desired result is obtained.

Spatial mode of the laser beam

This parameter defines the cross-sectional profile of the laser beam. A laser beam can have several modes, i.e. it can have different profiles.

The most commonly used mode in laser cutting applications is the Gaussian mode, as it allows maximum energy density to be produced, i.e. the beam is concentrated in a very small diameter point.

In this way, it is possible to obtain cuts and engravings with very reduced dimensions, with high processing speeds and the possibility of cutting larger thicknesses.

Other spatial modes, on the other hand, allow the beam to be focused on a larger surface area, thereby achieving lower energy densities.

Time mode of the laser beam

Lasers can be used in two modes, continuous wave or pulsed mode. The continuous wave mode is the most widely used (mainly in mass production), and allows very smooth cuts and thicker materials to be cut. The pulsed mode is used for more precise work, often with a low-power laser.

Wavelength

The way different materials absorb laser radiation depends on their wavelength. While some materials absorb the wavelength of the CO2 laser very well, others require different wavelengths and therefore other types of laser.

Aluminium and copper, for example, absorb the wavelength of the CO2 laser very little and require very high powers to be cut, which reduces production efficiency. Non-metallic materials such as wood and synthetic materials such as polymer plastics, on the other hand, absorb the CO2 laser radiation perfectly. Metals such as mild steel and stainless steel can also be cut with the CO2 laser with excellent results.

Polarisation

Polarisation refers to the ability of the laser beam to radiate in only one direction. This property differentiates the laser from non-polarised light sources, which radiate in all directions.

This parameter is important insofar as it affects certain characteristics of the cut. Generally speaking, when the cutting direction and polarisation have the same orientation, very thin, sharp-edged and vertical cuts are obtained. When the direction of the cut is the opposite of the one of the polarisation, the energy absorption of the material is reduced, resulting in a reduction in the speed of machining and a wider cut with rough, irregular edges.

Material characteristics

When configuring a laser system, the characteristics of the material must be taken into account. Not all materials are laserable. Some do not absorb certain wavelengths; others produce unsatisfactory results when subjected to the laser beam.

Thermal properties and reflectivity are the parameters of a material that need to be taken into account.

Thermal properties

From the point of view of laser processability, materials can be divided into two categories, metals and non-metals. The two groups respond differently to laser radiation and therefore offer different degrees of processability.

Metals have high thermal conductivity, a higher melting point and high optical reflectivity. For this reason, laser processing is very inefficient in most cases.

Non-metals, on the other hand, absorb laser radiation very well, particularly that of the CO2 laser, and can therefore be processed very efficiently. All it takes is a small concentration of laser energy to initiate the material transformations that carry out the processing.

Reflectivity

This property is especially relevant for metals. While we can generally say that all metals have a high degree of reflectivity, it is not a fixed parameter. The reflectivity of a metal can vary as the physical properties of the metal change. For example, reflectivity decreases when a metal is heated or when shorter wavelengths are used.

The reflectivity of a metal can be limited by the use of a non-reflective film applied to the surface of the material.

The polarisation of the beam also affects the reflectivity of a material.

Process characteristics

The laser machining process can be carried out in many different ways and use different technologies.

The following features of the machining process influence the final result:

• beam travel speed
• assist gas
• nozzle shape
• stand-off distance
• focal plane position and focal length

Beam travel speed

The travel speed of the beam is crucial in determining the final processing result. The thicker the material, the slower the laser has to travel because if it is too fast, it cannot penetrate the material.

In some cases this principle can be used for a purpose, such as laser marking and engraving.

On the other hand, if the laser proceeds too slowly, the material gets too hot, increasing the heat in the affected zone, which can lead to charring and damage to the material.

The right speed is the one that achieves the best quality for the desired result, as efficiently as possible.

Gas assist

In some cutting processes, the laser emission may be accompanied by a gas jet. This technique makes it possible to improve the efficiency, speed or quality of machining.

Some of the most commonly used gases are oxygen, used to cut mild steel, nitrogen, to cut nickel alloys. Helium, argon and other inert gases and simple compressed air are also used.

The gas jet can be either coaxial to the laser beam or directed. The final decision depends on the characteristics of the desired processing.

Nozzle shape

The nozzle is the device through which the laser beam is irradiated onto the processed surface. Its configuration has an influence in determining cutting characteristics such as shape, size and edges.

Stand-off distance

This parameter is determined by the distance between the nozzle and the processed surface. The spray distance affects the gas flow. Too great a distance can cause turbulence, which creates irregularities in the cut. If, on the other hand, the nozzle is too close to the work surface, splashes of molten material can damage the laser’s focusing lens.

Focal plane e position and focal length

The laser needs to be focused on the working surface at all times. The focus point must therefore always be on the processed surface, in order to achieve maximum energy density and precision. Controlling this parameter is essential to obtain good quality and uniform processing along the entire path of the laser.

Every laser configuration is specific

In summary, it is clear that it is not possible to standardise laser applications. The processed materials, the characteristics of the process and the technical characteristics of the laser system determine the type of configuration one should use. Contact us: our experts can define a process that suits your needs!

Laser marking is one of the most common industrial processes. In its broadest sense it consists in using the laser beam to create marks on the surface of a material.

The process is simple: the laser heats a layer of material, instantly vaporizing it. The visual contrast between the part that has been processed and the rest of the material is the engraving.

CO2 lasers are the ones most used for this type of application. They are highly versatile and suitable for laser marking applications in virtually any industrial sector.

Laser marking lives under the umbrella of galvo scanning applications. In this family of applications, a scanning head is used to focus the laser beam on a surface. In other words, the scanning head moves around the laser beam (which otherwise would travel in a straight line) towards the points that need to be processed. It does so through special mirrors connected to galvomotors.

The scanning head is key in galvo scanning, and it is what gives this application great flexibility. The scanning head makes it possible to use the laser to impress any type of sign on a surface: from simple alphanumeric codes to complex images, for the impression which using laser is a winning strategy.

Compared to traditional systems, laser marking applications have several advantages:

• cleanliness and speed
• precision
• versatility on materials
• possibility of automation
• respect for the environment
• durability over time

Materials

The versatility of the CO2 laser allows laser marking to be applied to a wide range of materials. This family of lasers interacts very well with carbon-based materials such as thermoplastics, wood and its derivatives, fabrics and organic materials in general. Here is a list of the most used materials in laser marking applications.

Wood and derivatives

Wood and its derivatives are used in a large number of industrial sectors. Whether it’s packaging or signage, laser marking can be used to apply various types of signs or decorations. Regardless of the desired effect, the process will be fast and effective.

Plastic

Plastics and thermoplastics are today widely used for an infinite number of applications, especially in the packaging industrial sector. Acrylic, polyethylene, polyamide and similar plastics undergo laser marking very easily with excellent results.

Metals

Laser marking is very effective also on metals. Though the CO2 laser is not the most suitable for cutting metal, it is perfect for modifying its surface because it produces very sharp and clear incisions.

Fabrics and leathers

Laser marking is perfect for processing fabrics and leathers. Both natural and synthetic fibers interact very well with the CO2 laser.

Laser can be used on these materials for numerous applications ranging from finishing fabrics to decorating garments. The main advantage of laser marking for fabric is that it considerably decreases the use of water and chemicals, thus reducing the negative impact the textile sector has on the environment. Today, the majority of laser marking applications on fabric are on denim.

Glass and ceramics

Laser marking lends itself well to the decoration of objects made of glass and ceramic. In this application laser marking is mostly used for the decoration of finished objects. Glass objects can even be decorated from within. The laser’s scanning head manages to reach the inside of the glass object, creating a three-dimensional image.

Biologic materials

The application of laser marking on biologic material is a recent thing. These materials are rich in carbon and therefore respond very well to the wavelength of the CO2 laser. The food industry has finally caught on to the benefits of the laser process that is very useuful for this sector thanks to its sterility.

Industrial sectors

The fact that this technology offers extreme flexibility in terms of choice of processed materials multiplies laser marking applications and opens it up to numerous industrial sectors. Indeed, it can be said that virtually any sector that uses compatible materials can benefit from laser marking applications. Here are some examples.

Automotive

In the automotive sector, laser marking can be used for a great number of purposes. An example is removing polyammid sheathing wrapped around the wires used in motors. Thanks to laser this process can be greatly streamilined, allowing for great economies in the production process.

Due to the flexibility allowed by the laser and the very low cost of the single machining cycle, laser marking lends itself very well to taylor made applications. From a commercial point of view this means that it is also possible to offer services such as interior customisation at a very low price and with a great economic return.

Labeling and packaging

The packaging sector is perhaps the one in which laser marking has most applications. Personalization and automation rule this sector so that the full potential of laser can be fully exploited. There are different types of applications that range from decoration of packaging to the engraving of identification codes and logos.

Laser labeling of food products is becoming increasingly popular. This application also has a name, natural branding. Laser labeling consists of replacing the self-adhesive label applied to products with a label engraved directly on the product by laser marking.

This labeling method makes it possible to obtain 100% compostable products and to reduce the use of packaging. On the one hand, adhesives composed of chemical substances are not used, and on the other hand, the consumption of potentially polluting plastic materials is reduced because the waste of the adhesive label substrate, usually not visible to the consumer, is eliminated. Laser labelling has been successfully applied both on fresh products and on cheeses and cold cuts.

Display panel production

The production of information panels is another great field of application for laser marking. This application is very efficient on the most commonly materials used in this industry (acrylic plastics, aluminum, glass and wood).

Laser marking makes it possible to design complex logos and to engrave writings of any type and length.

In contrast to traditional techniques such as screen printing or engraving, laser marking is indelible and therefore has a considerably longer life. The production process is also much faster and cleaner.

Textile, fashion and interior design sector

In recent years designers from around the world have discovered laser marking. Laser makes it possible to go directly from the design phase to the production phase.

This feature makes it ideal in areas where creative experimentation is a competitive advantage.

In fact, creating prototypes and experimenting with creative solutions is much easier if you follow a digital production paradigm (of which laser is part). It’s a quick step from the design on the computer to the finished product. Furthermore, laser can offer the designer more freedom from physical limitations imposed on his design by means of production.

For these reasons, laser marking is increasingly used in creative sectors. As we’ve seen before, laser can be used in the textile sector for the finishing of fabrics (e.g.: the coloring of jeans), but also for the creation of ornamental motifs on fabrics or both leather and faux leather for the clothing or interior design sectors.

Even wallpaper, curtains and carpets lend themselves very well to the application of decorative patterns by laser marking.

Another application in the interior design sector is the decoration of ceramic tiles. Original and complex patterns can be applied to ceramic tiles or other objects at a very low cost.

What is your application?

As seen in this article, laser marking can be applied to many areas. This technology grants important advantages in terms of speed and efficiency of the production process. It allows you to respond promptly to the demands of constantly evolving markets.

At El.En., we have a long experience in the production of CO2 laser systems for marking. Do you have an application in mind that could be implemented with laser technology? Let us know and we will be happy to find the solution that best suits your needs.

One of the most frequently asked questions we receive on this blog is about the difference between fiber optic Lasers and CO₂ Lasers. These are the two types of lasers most used for industrial application. If compared to fibers lasers, CO₂ lasers have numerous advantages that fiber lasers don’t have.

Both the CO₂ laser and the fiber optic laser work in the infrared spectrum. There is however a substantial difference between them.

A typical fiber optic laser works at a wavelength of 1.064 micrometers. It is used in very specific sectors, such as metal cutting, which require a very high concentration of power.

The typical wavelengths of our CO2 lasers are 9.3, 10.2 and 10.6 micrometers. This flexibility makes it possible to work with different types of material. The area of application of carbon dioxide laser is not limited to metals only but can also be applied to wood, acrylic, glass, paper, fabric, plastics, films, leather, stone, etc.

Thanks to this feature, the use of CO₂ laser has spread to a wide variety of industrial applications in recent years. Its flexibility and versatility make CO₂ laser the most used type of laser. It offers both high quality and the ability to satisfy most customer requests.

Versatility is not the only selling point of the CO₂ laser has over fiber laser. Here are other features that make the CO₂ laser the ideal choice for most applications:

• More precise when cutting thick materials: the CO₂ laser operates at a wider wavelength therefore it is more suitable than the fiber optic laser for processing thick materials. It also leaves a much smoother finish
• Uniform quality: the quality is the same on all materials whilst with the fiber optic laser it can be slightly different depending on the density of the processed material
• Straight line cutting speed: a CO₂ laser is faster at cutting in a straight line, and also has a faster penetration time once the cut has been initialised
• Possibility of control: the CO₂ laser can work with materials of different thickness. The power and duration parameters of the laser beam can easily be adapted to the technical specifications of the material.
• Greater safety: the light emitted by the CO₂ laser does not have a blinding effect. It is therefore must simpler to make the production line safe.
• Ease of implementation: the CO₂ laser makes it possible to create light and compact machines, capable of satisfying all production needs, even those of smaller dimensions.

CO₂ laser: versatility and reliability

On the basis of what we have written, it is clear that the choice between fiber laser and carbon dioxide laser depends on the type of application, i.e. the quality of the material and the technical requirements of the production.

If the fiber laser is particularly effective on metals, the CO₂ laser offers much more versatility and control. It allows to process most plastic materials and all organic materials but it can also be used on metals for surface treatment and laser marking operations. It also has a long history of industrial applications, making it a reliable and safe tool.

The CO₂ laser is therefore the best choice in most material processing industrial applications. If you have a process in mind that could be carried out using a CO₂ laser, contact us, and we will be happy to find the application that best suits your needs.

Until recently and partly still, industrial processes were focused on mass production. This encouraged a tendency to standardize products and processes, to reduce the number of possible customizations and to maximize the number of pieces produced thus increasing the company’s profit.

A production paradigm of this kind could work as long as the relationship between producers and customers was controlled by one side. The market bought what the producer offered. Recent technological advances, combined with changes in the market and client requests, have brought about a paradigm shift.

Highly customized forms of production, which were previously economically unsustainable, are now possible thanks to the use of technology and digital manufacturing processes.

Laser is the cornerstone of this change and has revolutionized many sectors allowing the reduction of production costs, the speeding up of production and the possibility of creating customized products on a mass scale.

This last statement might seem like a paradox, but to fully understand its scope, one must change the traditional way of looking at industrial production processes.

Think like a laser

The acquisition of a laser system is not just the acquisition of a new machine. It also requires the adoption of a new way of thinking about production. It becomes necessary to know the advantages that laser offers, exploit its strengths and use it productively and economically.

Let’s go over laser technology’s strengths point by point: versatility, precision, cleanliness, speed and lack of contact.

Versatility

Laser is versatile on many levels. First, CO₂ laser can work with a wide range of materials. This type of laser gives its best results on materials of organic derivation (wood, paper, cardboard, leather, fabrics, acrylic plastic materials, etc.) on which it can effectively perform any type of processing. On the other hand, CO₂ laser has a more restricted range of applications on metallic materials, particularly in the field of laser engraving and marking or for surface treatments such as paint removal.

Precision

The very nature of the laser beam makes it a highly controllable tool. Its parameters and features are easily managed with a software, and they can be set according to the desired result. This feature of laser has paved the way for precision machining and made it possible to create perfectly calibrated pieces based on the functions for which they were created.

An example of this type of application is the perforation and cutting for food industry. For this particular type of packaging, holes are made on the surface of the plastic film to improve the breathability of fruit and vegetables. The perforations vary depending on the product’s characteristics.

This is just one example of the applications made possible by laser technology. Other examples include the perforation of leather for car interiors, the manufacture of pipes for irrigation, the microperforation of instruments for the health sector.

Cleanliness

Of all the machining processes based on the removal of material from a workpiece, laser is the one that produces the least residue because the material is removed by sublimation. Even the processing waste (i.e. the parts of unused raw material) can be reduced thanks to nesting, which is managed by a special software.

Computer control makes it possible to make the most of the work surface. In most cases, one can obtain more finished pieces from the same material using this technology than with traditional methods. In this respect, laser represents a leap in quality if compared to other processes based on chip removal, or on the use of various types of abrasive fluids.

Moreover, the need to remove production waste is reduced. The laser beam concentrates high energy on the processed material which, undergoes chemical-physical alterations that cause its instant removal.

This feature makes laser ideal for all the industrial sectors where the absence of processing waste and a clean production environment are key. Consider, for example, the field of electronics, the medical device sector, and the packaging sectors.

The absence of waste and other residue also has an economic advantage: in fact, the cuts made with the CO₂ laser do not need further finishing. They are performed without leaving the slightest trace of material behind. Each piece therefore takes less time and money to produce.

Speed

In industrial processes, the speed at which work is performed is a fundamental requirement.

Laser is capable of performing work at a very high speed. This feature is particularly evident in the execution of complex design operations.

Processes such as the engraving of barcodes and identification codes, the decoration of fabrics, or the cutting of complex shapes are carried out practically instantaneously by a laser beam.

But even slow and expensive processes such as fabric finishing can be effectively replaced by a CO₂ laser. A previous article explored the finishing of denim fabric through laser scanning processes. In the past, the discoloration of jeans was performed using very slow chemical processes, which were expensive in terms of resources and extremely polluting.

The integration of laser in the production chain of these products has made it possible to significantly speed up the production process, achieve considerable savings in terms of resources, as well as reduce the ecological footprint.

Lack of contact

Laser is a non-contact process, a feature that comes with many benefits.

Firstly, tool wear is limited. As a result, maintenance costs are reduced. The laser beam, (the instrument that physically performs the processing), emits a coherent and focused beam of light. Since there is no mechanical contact between the tool and the material, it wears less.

Of course, even a laser source needs routine maintenance. The laser-producing medium, CO₂ gas, is consumed over time. The self-refilling technology developed by El.En. for its laser sources has made it possible to greatly reduce maintenance. The gas can be refilled in-house which reduces the machine’s periods of inactivity.

The lack of mechanical limitations on laser movement, the small diameter of its radius and the possibilities offered by numerical control combine to give very high tolerances during production. Engraving or cutting complex shapes become extremely simple. This is a feature that makes laser an ideal choice for all the sectors that use design to get a competitive edge, such as fashion.

It is clear that the introduction of laser in the production process is advantageous for all the applications where personalization, speed and production flexibility are decisive.

Companies that deal with productions with a high level of customization, which need precise processing, which must respond to a market with multiple demands, can compete in a cost-effective way with other companies that make economies of scale their strength.

Whatever your application is, please, contact us using our form. We will be glad to support you with our experience!

In recent years, CO₂ lasers have increasingly been used as work tools in the abrasive material sector. CO2 laser technology can perform advanced processes which are well-adapted to new generation products (suitable for the most innovative processes and sectors).

The production of abrasive discs is a perfect example of this type of production. One of the most appreciated features of an abrasive disc is its ability to facilitate the elimination of debris from a work surface. In order to obtain the desired effect, there are holes on the disc to facilitate the expulsion of debris. The holes need to have a certain size, be evenly and precisely distributed on the disc, and have a specific surface density to be effective.

Nowadays, in the abrasive disc production sector, the most used tools are mechanical ones like blades and dies. The main advantage of these tools is that they are cost effective.

However, the production of abrasives with dies also has several disadvantages:

• Limited accuracy. Due to technical limitations, blades and dies cannot perform work under a certain diameter, with narrow spacing or in special arrangements. Therefore abrasives produced with mechanical methods can hardly reach the optimization levels required by the most advanced applications.
• Deformed surfaces. The cutting process is achieved through mechanical contact. This exposes the processed object to the risk of deformation. The disks produced from a matrix sheet are often deformed by the pressure of the dies. The disc acquires a concave or convex shape which reduces the usable abrasive surface and therefore makes it less effective
• Tooling costs are increased. Cutting tools get worn quickly by their application to abrasive materials. These tools need to be replaced frequently which increases the overall production costs.
• Lack of adaptability. Most shape variations and modifications require the acquisition of different cutting tools.

Laser technology for abrasive materia die cutting

The CO₂ laser is an optimal production medium for flexible abrasives since it has none of the previously mentioned shortcomings. In recent years the cost oflaser material processing has lowered, and therefore become much more used the abrasive material sector.

Laser’s main advantages in cutting abrasives are:

• Easy to calibrate. Characteristics such positioning, distribution, and the diameter of the holes (which can be very small) can be calibrated with great precision. Laser is therefore suitable the advanced, high precision processes required by the market
• No risk of deformation. Laser is a non-contact process therefore the risk of the material getting deformed are close to none. Abrasive discs produced with laser are much more efficient than abrasive discs produced with mechanical methods
• Low maintenance costs. Lasers used for the processing of abrasive materials are not subject wear because there is no physical contact between the tool and the material
• Flexibility. Laser technology makes it possible to totally or partially modify the shape to be cut by simply making changes to the processing file on the software. This method saves on time and the cost of procuring a new mechanical tool

A very promising sector

These are just some of the possible laser applications in the field of abrasives, and each has its own characteristics and needs. Laser processing of abrasives is a very promising field of application. Our CO₂ laser sources combined with our galvanometric scanning heads are ideal for this type of application: powerful, effective and precise, they can be easily integrated into existing production systems or to new digital converting machines as well as to an industry 4.0 production chain. Contact our El.En.experts to answer your questions and find the right solution for your needs.

Laser material processing started a revolution in the industrial world. It has brought quantitative improvements such as an increase in production speed, and qualitative ones, such as the possibility of creating customized products with high added value, even on a small scale.

The packaging sector immediately understood that the use of laser could offer endless possibilities for innovation. Packaging is a fundamental aspect of most manufacturing sectors and laser technology is taking a strong foothold in this growing market. Laser reinforces and improves the characteristics of packaging materials, helping them perform their desired function even better.

Packaging in itself performs a wide range of functions:

• First of all, it has a protective function. Packaging must protect the product from external agents. In the case of food, it prevents deterioration and guarantees the product’s integrity
• Secondly, it has an aesthetic function. Packaging must convince the consumer to choose a specific product on a supermarket shelf. In a world increasingly rich in consumer goods, packaging can sometimes be a product’s only distinctive factor
• Thirdly, it has an informative function. Important informations such as ingredients, expiry date, production lot or barcode must be visible on the product
• Last, but not least, it has a practical function. Packaging must make the product easy to handle and use. Thanks to laser cutting, packaging can be designed in such a way as to facilitate the use of the product itself. Easy to open packaging such as food bags or easy cutting ones such as yoghurt pots are two examples of this type of packaging.

Functional and fast packaging with innovative technology is now easier than ever with laser technology.

Why process packaging with laser?

Laser-based manufacturing is extremely flexible and give the possibility to experiment on a great variety of applications. Laser, and in particular CO2 laser, achieves its maximum levels of efficiency when it processes the most commonly used packaging materials such as:

• paper and cardboard: used to produce boxes and packaging, these materials can be cut, marked and perforated. The producers can thus create boxes with original shapes that can bring out the abstract qualities of the product
• wood and derivatives (for example MDF) are used to create innovative packaging. Food crates to transport produce are but one example
• plastics and derivative: thermoplastic film polymers such as polypropylene, polyethylene and PET are among the most used materials for packaging. Plastic film can be adapted to the most diverse needs through cutting, marking or drilling processes. Food safe plastics benefit greatly from these applications. For example, containers can be perforated, to regulate the passage of air or to create filtering systems, but also be cut into complex shapes. Other applications in this sector include the cutting of plastic films used to make various types of packaging, including aluminised plastic films

Laser technology is also a great asset for the packaging sector because of the possibilities offered by automation. The benefits of a fully digitized and automated manufacturing process are significant. The automated process reduces the possibility of errors, allows changes to easily be made in real time, guarantees extremely uniform results while having standard and repeatable characteristics.

For example, imagine being a manufacturer of plastic parts for the automotive industry. A digital manufacturing workflow would allow you to automatically use laser to engrave a production batch number on a piece’s packaging, centralize this information in a database, as well as have a system that allows you to trace all the logistics, from the production to the end customer. Should there be a defect or a malfunctioning piece, the production batch (or any other information) could easily be looked up directly in the database.

Laser processing in the packaging sector

Many of the advantages derived from laser processing are due to the fact that laser is a no-contact technology. The laser beam is used as an energy source that gets concentrated on a specific area in order to perform an application. Here are some of the main applications laser systems can perform.

Laser cut

In laser cutting, the beam vaporizes a portion of material according to a defined path. The final quality of the cut depends on the material. CO2 laser cut creates extremely clean edges on most materials. The final piece does not need further finishing and is ready for use.

Laser cutting can be used to cut windows and openings on a package, to create details such as tear openings, easy-to-open tabs, filtering systems, to cut pieces of packages for later assembly.

Laser marking and engraving

Laser marking and engraving use laser to imprint a mark on a material. The two processes are very similar.

We speak of laser marking when the transformation of the material occurs only superficially. In the case of laser engraving, there is a deeper transformation of the material.

In the first case the sign, even if indelible, results in a discoloration of the material. In the second case the sign is much deeper and it is also possible to obtain a tactile sensation on the incision.

Manufacturers mostly use laser marking and engraving on packaging. Laser allows them to permanently engrave their logo in remarkable detail. Expiration dates or production batches can be applied on the packaging, taking advantage of the automation capabilities offered by laser systems. This application is known as laser coding.

Perforation and laser microperforation

Drilling machines use laser to create holes on a material. Typically the holes are made on sheets or slabs of material. Finished pieces can also be perforated.

The holes can have different dimensions. Indeed, the possibility of varying the size of the perforations in order to adapt them to a specific purpose, is the true advantage of laser perforation.

The term laser microperforation is used when the holes have microscopic dimensions. Laser perforation and microperforation have numerous applications in the packaging sector.

Laser perforation can be used to create filters and other features on the packaging, such as the creation of perspiration holes for food trays.

Laser microperforation can be used to create breathable packaging (such as modified atmosphere packaging). In this case, microperforation can be used to calibrate the packaging to the product and increase its shelf life. The processing of flexible plastic films takes great advantage of this application which allows you to create wraps capable of significantly extending the life of the product.

A sector in constant evolution

Laser technology makes it is possible to decide on a desired result and calibrate the process on it. Many laser applications have not yet been tested which means there is a whole world of opportunities to explore. The tailor made application that could bring numerous advantages to your production system could be just around the corner.

Here at El.En., we have experimented with thousands of laser applications for packaging over more than 35 years. If you work in this sector and are looking for your next personalized application, contact us and let us know what you need. We will be happy to help you build the ideal solution for your application!

Laser marking has become a standard in many industrial sectors. Its advantages are flexibility, speed, precision, the quality of the etched signs, eco-friendliness.

The vast majority of laser marking applications are aimed at identifying products and components. This role is traditionally played by labels of various types, printed or engraved and subsequently applied to products. Laser marking replaces the labels and allows information to be engraved directly on the surface of the product or component.

How laser marking process works

The laser marking process takes place through the interaction between the laser beam and the surface of a material. This interaction triggers an ablation process, through which a superficial layer of variable size is removed. The final result depends on which type of material is being marked and which type of laser is being used. The CO2 laser is the most used in laser marking processes because it can be applied to many materials.

What information can be laser marked

Laser technology makes it possible to engrave all kinds of information about a product. Some examples are:

• barcodes
• QR codes
• sequences of alphanumeric characters
• production lots and expiration dates
• copyright information
• manufacturer’s logos
• compliance logos

The advantages of laser labeling

Currently, there are three main ways to apply information on the surface of a product:

• Inkjet printing. It prints alphanumeric codes using a dot-matrix printer. This type of application is used on organic products that could be damaged by the laser’s heat. However in recent years it has been found out that laser can also be used successfully to label fruit, vegetables and other organic materials. Even if ink-jet printing guarantees a high level of productivity, it isn’t always long lasting since different materials retain the ink better than others, and the maintenance of the production line can be costly.
• Metal stamping. It prints signs by plastic deformation of the material’s surface. The imprinted marks are evident and can’t be counterfeited easily. It can be applied on metal labels that are then affixed to the different components, but it is not suitable for direct marking applications on the component itself. Metal stamping requires the use of a specific imprinting tools and dies, which have high maintenance costs. Also, changing the information to print is expensive because it requires changing the printing tool.
• Self-adhesive labels. Information is printed on a self-adhesive label which is then applied to the product. Labels are not very environmentally friendly because the back of the stickers are discarded.

Compared to these marking systems, the creation of labels by laser marking has undoubted advantages.

• Quality. Laser markings are perfectly defined and never fade, however much the product is subjected to intensive use. Laser technology suits well where preventing counterfeiting is necessary.
• Cost. While it is true that laser requires a greater initial investment than the other methods, it also has much lower maintenance and processing costs. Laser is advantageous when used in production processes that foster its strengths, that is favor high levels of customization, highly automated management of processes and perfection of the output.
• Flexibility. The printed information can be modified and updated very quickly without the need to adapt work tools or its ensuing costs. Tooling changes and machine preparation are reduced to practically nothing. Laser marking makes it possible to access a piece’s recessed areas that would remain inaccessible with conventional technologies.
• Respect for the environment. Laser labeling is more eco-friendly than traditional labeling since the consumption of plastic, ink and glue for labels is reduced considerably, as well as the costs associated with the disposal of unused sticker’s support.
• Efficiency. The information on the labels can be immediately digitally processed. It is therefore possible to increase the traceability of the processed pieces. Laser marking of labels can also be made on the fly.

Applications

There are many laser marking applications which range from the traditional ones like the marking of parts and components to the more advanced ones like the laser marking of food. There are many examples of applications in this latter area:

• engraving of codes on eggshells: this case study shows how laser marking can replace ink printing on eggshells
• marking of cold cuts and cheese wheel: cheese wheels and cured meat can be easily marked with laser. In this application laser marking replaces hot marking
• marking of fresh produce: in this application, laser marking is used to engrave information and logos directly on the surface of fruit and vegetables. In this case, laser marking replaces the self-adhesive labels

Other application examples include:

• Automotive: windshield engraving, identification of car components
• Gifts: product information
• Electronics: laser marking marking of silicon boards for integrated circuits
• Engineering: marking of construction components

What is your application?

You might be considering how laser marking could help you improve your business. Here at El.En., our team of experts will be happy to help you choose the right laser system for your needs. Our laser sources and our scanning systems are used all over the world and help thousands of companies create high quality products. Contact us to learn more.

Paint stripping operations have always been an expensive and time consuming process. Removing paint from an object, especially a large painted surface, requires many hours of work. In most cases, solvents and big quantities of water are used to strip paint which has negative consequences on the health of workers and the environment.

An alternative to traditional paint stripping is laser paint removal, an effective, fast and environmentally friendly method to remove paint from a surface.

Traditional paint removal methods

Paint has been used to cover surfaces and object since ancient times. Their function is twofold: on one hand they protect the material they cover from wear and tear, on the other, they strongly contribute to the aesthetics of the object.

Practically all industrial sectors make use of paint, but for some, it is a crucial part of the production process.

This is the case, for example, in the vehicle manufacturing industry, whose objects – airplanes, ships or trains – have large painted surfaces.

Aircraft can be repainted in cases of general maintenance or after a change of ownership.

Traditionally, chemical and physical methods are used to remove paint, i.e. the paint is softened with solvents and then scrapped mechanically. This technique has other drawbacks:

• it uses of highly polluting substances
• areas that don’t need stripping need to be masked to avoid damage
• the chemicals used need to be rinsed off, which causes a high water consumption
• it produces potentially toxic waste and chemical vapors which are bad for operators and the environment

Laser depainting makes it possible to overcome these drawbacks, transforming stripping into a fast, effective and precise process.

The process of stripping paint with laser

The laser paint stripping process consists in irradiating the painted surface with a laser beam that vaporizes the paint layer.

The paint is removed practically instantly thanks to a sublimation process. Compared to traditional methods, laser paint stripping is a much faster process. In a few hours it is possible to remove tens of square meters of paint from a surface. The only consumption of resources is the electricity used to power the system.

Harmful solvents or other chemicals are unnecessary. Just apply the laser to the surface and in a few seconds, the paint is removed.

Which technology for laser paint stripping?

Defining the technology suitable for a laser stripping system in detail is difficult without knowing its specific context of use. The fundamental components of a system of this type are a laser source and scanning head.

Theoretically, the choice of the laser source depends on the chemical composition of the paint to be removed. It is a well known fact that each material absorbs a certain wavelength more or less well. The most efficient laser source has a wavelength that is best absorbed by the material it is trying to sublimate.

However, an important consideration must be made. It would not be viable to create a paint stripping machine which could only strip on one type of paint. A laser depainting machine must be able to remove the greatest number of paints on the market.

The CO2 laser offers the best compromise between reliability and versatility. A carbon dioxide laser source is therefore the most suitable tool for this application. The wavelength of 10.6 micrometers is in fact effective on most of the paints on the market because it is highly absorbable. It can remove both white and colored paints, without damaging the underlying surface.

The scanning head is the other fundamental element of a system for laser stripping. This device is used to precisely direct the laser to a specific part of the surface and to keep it focused on that work area. These two characteristics make it an extremely precise work tool.

The choice of the head depends not only on the laser used, but also on how much surface needs to be covered. Large surfaces require particular scanning heads such as the El.En. AZSCAN HR70 which manages to cover an area as big as 2300 x 2300 mm.

The fundamental components of a laser system for paint stripping are The laser source and the scanning head. However, their implementation is strongly guided by the type of work needed. The possibilities are endless and each application requires the study of a tailor-made system. Contacting our technicians is the best way to find out the possibilities this application offers.

Glass is one of the many materials that can undergo CO2 laser treatments. Laser is most often used for markings or cuts. In this article, we will explore how compatible glass is with laser technology and its possible applications.

Glass composition

Glass is a material of natural origin, composed mostly of silica (SiO2). The material is heated until it reaches melting point and then left to resolidify. This process yields glass, a transparent material with a great resistance to corrosion.

Glass does have some defects, though. It is fragile and has a low resistance to thermal expansion.

Types of laserable glass

It is important to take its negative characteristics into consideration before applying laser technology to glass. Its type of composition and production will be deciding factors when choosing where to use laser.

Composition

Most of the glass available on the market isn’t composed solely of silica. Depending on the glass’ final use, other components are added to the silica to modify the material’s properties.

Adding substances to the material does alter its ‘laserability’. For example, laser technology cannot be used when metal has been added to glass. Crystal is part of this category of glass. In order to increase transparency, lead is added to the composition, thus making it incompatible with laser.

Production

Most glass is produced industrially. Nonetheless, one can still find productions of artisanal glass objects; obviously at a higher price.

The first type of glass has a more uniform structure which makes it a better candidate for laser applications. Artisanal glass, on the other hand, isn’t as easy to use with laser. The glass can contain structural and compositional inconsistencies like microfractures. This glass could easily crack when exposed to the heat generated by the laser.

How laser technology works on glass

Though laser applications usually work by sublimation for most materials, in the case of glass, the process is different. As previously mentioned, glass has a low tolerance for thermal expansion. Laser technology takes advantage of this characteristic by generating fractures at a microscopic level. These result in markings or cuts.

How does this process take place? Glass contains trapped microbubbles of air. When the laser touches upon the surface, it heats it and causes the dilatation of these bubbles. Due to the material’s lack of flexibility, this dilatation generates the aforementioned micro-fractures.

CO2 laser markings on glass

Laser marking is the most common technique applied to glass. It is usually used for decorations or the marking of codes and other information.

Productions using laser have many advantages compared to traditional methods. They are cleaner, cheaper and offer a much wider range of applications.

Markings can be done in different ways, depending on the type of glass.

Soda glass

Soda glass is the most common form of glass. It is used for windows, bottles, glass flatware and other commonly used glass objects. It works well with laser technology.

On this type of glass, markings are made by generating thousands of microfractures on the glass’s surface. Thermal shock causes the dilatation of the glass, which, due to its rigid nature, fractures at a microscopic level. The final result is an opaque marking with a satin finish. It looks very similar to results obtained using more traditional methods, but at a much lower price.

Examples of this process can be found in the decoration field (decoration of glasses and flatware, windows and cabinets), in the car industry (identifying codes markings on car windshields and windows), in the production of glassware for laboratories (measurement markings).

Quartz glass

Quartz glass is obtained from the fusion of quartz rather than silica. It has a high resistance to heat, great optic transmissibility and a high resistance to corrosion.

CO2 laser markings on quartz glass are done through superficial fusion. The material’s fusion modifies the reticular structure of glass making light refract differently on the markings compared to the rest of the surface.

Boro-silicate glass

Boro-silicate glass, known commercially as Pyrex, is obtained by adding boron and other composites to the silica. The chemical reaction produces a glass that is highly resistant to thermal expansion. It is usually used for the production of flatware and oven trays.

Boro-silicate can undergo CO2 laser markings.

Contact us for more information on laser marking of glass.