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.

Composite materials are known for their extraordinary mechanical and physical properties. They are created by combining two different materials, resulting in a new material with better properties than their component materials taken individually.

Fiber reinforced polymers are some of the materials in the composite family that have found widespread use. These materials are manufactured by incorporating a fibre of some kind into a resin polymer matrix.

Fiberglass is one of the first materials to have been made in this way. Invented in the 1960s, it has now become an indispensable material for many sectors, particularly the nautical one. Today, there are other materials of this type such as aramid fibre also known as kevlar and carbon fibre reinforced plastics (CFRP).

Materials produced this way are light and resistant and at equal mass, are considerably more performant than other traditional materials such as wood or metal. They can also offer great plasticity which makes them easy to mould into any required shape. Thanks to these characteristics, composite materials are used for technologically advanced applications in sectors such as the nautical, aeronautical or automotive industries.

Carbon fibre reinforced plastics

CFRPs are perhaps the most advanced of all the composite materials,

To produce CFRP, a carbon fibre fabric is incorporated into a polymer matrix. The resulting product is extremely light and strong. At equal mass, it is 25% lighter than aluminium and 60% lighter than steel. This explains why it has found use in the aeronautical industry and in the sports competition sector for the construction of super light vehicles.

Once made, however, CFRP must be cut into the required shapes for their future function. Normally, this is done using mechanical methods. However, these have a major drawback. The strength of the carbon fibre quickly wears out the cutting tools, which therefore have to be replaced very frequently, making the process very costly.

Laser cutting technology is a valid alternative to the mechanical cutting of CFRPs. Both the carbon fibre and the polymers that make up its matrix absorb the 10.6 micrometre laser radiation produced by the carbon dioxide laser very well and can be cut very efficiently.

Cutting CFRP therefore has two main advantages:

• a contactless process: it is possible to cut CFRP without the typical mechanical forces that wear out the cutting tool. This significantly lowers the production costs of each individual part.
• very high tolerances: the laser can make cuts with very narrow angles and produce extremely precise parts very easily. This feature is crucial for advanced technological sectors where it is important to maximise the performance of a given component.

The material of the future

CFRP will become more and more popular over time. This material is of increasing importance and will spread to an ever wider range of sectors.

Finding a cheap and fast way to cut it into the most diverse shapes will become crucial. The CO₂ laser is a viable alternative to the mechanical cutting methods currently used.

If you are considering a laser application to process carbon fibre, contact us: and we will design a customised application to suit your needs.

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.

Bags and pouches of all kinds have been conquering the packaging market for several decades now. Flexible packaging adapts to the shape of the object it covers, so less material gets wasted. Laser perforation, also known as laser drilling, is a processing technique that allows the manufacturing of new packaging designs that at the same attract the eye and have advanced functional features. Laser perforation is but one of the many processing technique that can be employed in packaging manufacturing through laser.

In general, the great success of flexible packaging is due to its functional characteristics. The main functions of packaging are to first protect and preserve products, and second, to facilitate sales. Flexible packaging perfectly fulfills both functions in a terrific way. Not only does it protect the product from external influences, but it can also be easily processed to give it the shape that best enhances the product’s characteristics.

Here are some examples of the wide variety of shapes and configurations flexible packaging can have:

• stand-up doypack pouches
• heat-sealed plastic bags
• envelopes for product samples used for promotional purposes
• pre-printed plastic film reels

Packaging of this type is employed in various industrial sectors. The food industry is one of the ones that makes the most common use of it. Flexible packaging provides the delicate products of this industry with an optimal balance between weight, protection, hygiene and functional and commercial characteristics. Other sectors such as cosmetics, health care and detergent industries also make extensive use of them.

The materials used to produce these forms of packaging fall into into 3 basic families:

• plastic film – Polyethylene and polypropylene are the main thermoplastic polymers used, they provide high insulation properties
• aluminium foil – Aluminium foil is used when high protection against light or temperature changes is required
• polycarbonate – These are created by combining materials from the previous two families to combine the advantages of both materials

Laser perforation for flexible packaging

As we have already mentioned, flexible packaging has found widespread use in the food sector in particular. As more and more people live in cities, work and have little time to cook, the demand for fresh, ready-to-cook food has increased.

This type of packaging is used the most for products such as vegetables. In the fresh produce section of supermarkets, bagged vegetables have become the norm, and a convenient solution for people who want to eat vegetables but have no time to prepare them.

The challenge for producers here is not only to adopt sustainable packaging but also to maximise the shelf life of their products.

After being harvested, fresh food goes through a series of biological transformations that manifest themselves in the release of gases, water vapour and chemicals inside the bag. As a result, unsuitable conditions for product preservation are created inside the bag.

What is laser perforation?

Laser perforation makes it possible to overcome this problem. The creation of holes in the surface of the wrapper makes it possible to optimise the gas exchange between the inside and the outside environment. It then becomes easy to maintain the optimum conditions for better product preservation.

This technique is part of laser cutting processes. In this application, laser technology is used to create holes in the material. The most remarkable aspect of this process is that it makes it possible to define the characteristics of the holes very precisely, from their diameter to their shape. This gives this process a considerable advantage over conventional packaging methods. Whereas previously a manufacturer had to find the most suitable packaging already available on the market, with laser perforation they can customise the packaging to ensure optimum product preservation.

The advantages of laser perforation

Compared to traditional perforating methods for flexible packaging, laser perforation provides a number of advantages:

• Precision: like all digital processes, laser perforation offers all the precision given by the use of software. The size of the holes can therefore be changed according to a wide range of parameters, even during the same process.
• Protection of materials: laser technology minimises the possibility of accidentally damaging the material from which the plastic film is made.
• Automation possibilities: laser perforation is a fully automatable process. It can be incorporated into existing production processes in order to fully automate and increase the manufacturing quality of the whole production line. It can be used for roll-to-roll or sheet-to-sheet processing.
• Flexibility: different processes, within the same production cycle, can be performed with laser technology. The same machine can perform more than one process, like for example, perforating plastic film and marking information for product traceability.

What materials can laser perforation be performed on?

The best results in laser perforation are obtained with plastic film. Most thermoplastic polymers absorb the radiation of the CO₂ laser well and therefore lend themselves perfectly to this type of processing. As we have seen, polyethylene and polypropylene are the materials on which the best results are obtained. On these materials, the cutting edges are perfectly defined, the processing precise and clean.

How a laser perforation system works

Choosing the right laser perforation system amongst the wide range of options on the market depends on the material used, the type of application and the final purpose of the project. However, we can identify some constants in all systems.

A laser perforation system normally consists of 2 components:

• a CO₂ laser source: this is the device that produces the laser beam. You can find laser sources with different power options in the El.En. catalogue.
• a scanning head or focusing head: the laser scanning head is the device that moves the laser beam over a surface. In this way, perforations can be distributed over the surface according to production needs. This smart tool uses integrated control software and can follow any type of pattern. For simpler machining operations, this system can be replaced by a focusing head, which does not have a control system but allows the laser beam to be focused on a specific point that can be moved on one or two axes depending on requirements.

This combination of basic elements can be integrated into an infinite range of systems, from industrial in-line systems to stand-alone machines that do the processing independently. Laser systems can act on moving material from reel to reel or on sheets of material.

Contact us

The possibilities of laser perforation are endless. This article only covers one of the many possible applications. This technique can be used to create filters, disposable packaging, and packaging with particular and perfectly defined functional characteristics. Each application has its own peculiarities. Our job is to find the laser solution that gives you the best results for your application. If you think laser perforation might be right for you, send us a message and we will be happy to help you identify the best laser solution for your needs.

Paper processing is one of the main areas of application for the CO₂ laser. The world of paper converting has benefited greatly from the spread this tool. The CO₂ laser offers speed, efficiency and flexibility, allowing laser companies to meet the demands of an increasingly fragmented market.

Laser production processes also fit in perfectly with the digital printing processes that now dominate the converting industry. This is a sector that we know well at El.En. Over the years we have helped many companies introduce laser technology into their production processes. We have created numerous systems for paper processing, particularly for companies operating in the packaging sector.

Based on our experience, we will use this article to give an overview of laser applications for paper converting.

Laser and paper

Paper is part of our everyday life. There is no task or business that does not make use of some kind of paper material.

When we talk about paper, we include a wide range of materials. However, the various types of paper have a similar composition. At a microscopic level, a sheet of paper consists of a network of interwoven cellulose fibres, a filler, usually kaolin, and various chemicals derived from the manufacturing process.

The chemical structure of paper lends itself well to CO₂ laser cutting. When the laser interacts with the cellulose, it dissolves its molecular structure, reducing the material to its basic components carbon, oxygen and hydrogen.

This processing system is very advantageous as it solves the main drawbacks of traditional paper cutting tools.

First of all, the laser offers flexibility. One of the methods for cutting paper is using dies. Each die can only be used to cut one shape. In order to obtain a new shape, a new cutting die must be created. This places a limit on how much work a company can accept: if the production batch isn’t big enough to pay back the cost of the new die, it becomes economically disadvantageous to produce it.

Laser technology, on the other hand, is much more flexible because the entire cutting system is digitally controlled by software. Modifying the shape that needs to be cut simply requires software intervention. This makes it economically viable to process small production batches.

Mechanical cutting has another drawback. The use of blades is another method used to cut paper. This cutting mechanism produces dust and residues that are not compatible with modern digital printing processes, which are now predominant. This means that it is necessary to separate the printing and cutting phases.

Laser cutting processes, on the other hand, produce very little residue and are therefore compatible with digital printing processes. What’s more, laser technology is a completely digital process. It can therefore easily be used in integrated systems that can perform all the production processes required by the converting industry in a single step.

Another problem with mechanical systems is that they cannot achieve consistent high quality cuts. Blades carry the risk of creating irregular or poor quality cuts. Many applications, particularly in the packaging sector, require extremely precise cuts. Containers for liquid food products, for example, need to have perfectly sealed edges (i.e. where there are no loose, protruding fibres). Laser cutting achieves these results because heat seals the edges during the cutting process.

On the basis of what we have previously stated, the use of lasers is advantageous in situations where the use of mechanical cutting is not economically viable. Here are some examples:

• need for high quality and precision cuts
• production volumes of less than 1000 pieces
• need to create integrated digital printing and cutting production systems
• need to eliminate waste due to the high cost of production equipment
• execution of bespoke work
• execution of particularly complex cuts

Some paper laser cutting applications

It would be difficult to make a complete list of laser applications for paper, especially since many of these processes used to be carried out with mechanical cutting equipment. However, laser technology has made it possible to perform processes that used to be impossible or very difficult to do very easily.

One example of this is partial surface cuts, which make it possible to create packaging models with advanced features like easy-opening packaging or open-close. This type of application is particularly popular in the food industry. This type of packaging doesn’t require any tools to be opened and therefore adds value to the product itself.

Conclusion

CO₂ laser sources are ideal for paper processing. The CO₂ laser interacts perfectly with the chemical composition of paper materials. Using it in this sector is very advantageous. As you can imagine, however, the possible implementations are numerous.

We would be happy to put our extensive experience in CO₂ laser applications for the paper industry at your disposal. Feel free to contact us for information or a free quote.

Laser die cutting of labels is a digital converting process. In this application, the laser die cutter replaces mechanical dies in the execution of processes such as the cutting or trimming of label templates.

The use of laser technology is particularly advantageous. On the one hand, it overcomes the typical disadvantages of mechanical die cuts. On the other hand, it allows the same processes to be performed with a flexibility and precision impossible to achieve with diecuts.

In this respect, the laser die cutting process clearly shows the advantages of using lasers for labeling and packaging applications.

How the label production process works

The production of self-adhesive labels is one of the most traditional papermaking operations.

Typically, the label production process takes place in 3 steps:

• printing of the label on the master sheet
• engraving of the label template
• cutting of the label template

The die cutter is used for the operations of engraving the label and cutting it out from the master sheet to isolate the label from the sheet itself.

This processing technique has several disadvantages:

• in order to obtain new shapes to cut, manufacturers must create a new die cutter
• the mechanical properties of the tool do not allow complex shapes to be cut
• the cutting tool wears out quickly and needs maintenance to work efficiently

Given those features, a mechanical production system is only efficient if it can guarantee high production volumes. However, the market today rewards companies that are able to offer innovative, customised production processes that can support numerous orders with small production volumes. And from this point of view, a laser cutting machine is the optimal production tool.

Laser processing of labels

Laser die-cutting is based on an ablation process. The operation is carried out by a laser machine. The beam laser power, focused on the material, removes a portion of material through a chemical process called sublimation. By means of devices such as galvo laser head, it is possible to move the laser beam along a determined path. Digital control also makes it possible to precisely calibrate the instrument according to the desired type of processing. The operation is carried out at high speed.

There are two possible operations: laser kiss-cutting and laser cutting. Both are laser cutting processes, but differ in how deep they cut the material.

Laser kiss-cutting and laser cutting

Laser kiss-cutting consists of cutting the surface layer of a multilayer material. Adhesive labels are printed on master sheets. These sheets typically consist of two layers: a top layer on which the graphics are printed and a backing layer, onto which the adhesive is glued. In laser kiss-cutting, the laser engraves only the surface, freeing the adhesive template from the backing matrix.

In laser cutting, the beam passes through all the layers of material, freeing the adhesive from the matrix and reducing it to a unit.

The advantages of laser label die cutting

Laser finishing offer numerous advantages:

• the cutting path can be modified by simply loading a new file into the system
• the absence of mechanical contact allows particularly complex cutting paths to be followed
• laser cutters does not wear out and requires minimal maintenance

For a company using a digital laser die, it becomes possible to manage production in an innovative way. It can now make prototypes for the customer, start small volume production runs and accept numerous orders that wouldn’t be sustainable with traditional production methods. It is a true paradigm shift in the way we conceive production.

There is yet another advantage. In the digital converting industry, and particularly in paper converting, CO2 lasers are almost exclusively used. These laser systems are known to interact very efficiently with paper materials. This characteristic, coupled with the reduced production of processing waste, makes the laser an eco-friendly production tool.

Contact us

El.En. has developed numerous digital converting applications over the years. Contact us to find the application that best suits your needs.

Abrasives, part of a family of materials characterised by their great hardness, are used for processes such as polishing or the sanding of surfaces. They are available in a wide variety of shapes and types and lend themselves to a multitude of processes.

These materials can be moulded into a large number of shapes: discs, brushes, wheels, cutters, grinding wheels. However, traditional abrasive processing methods have limitations that can be overcome with laser processing.

In this article we will look at the 6 advantages of using laser technology in the manufacturing process of abrasive products.

1. Laser is a non-contact process

The main problem in the manufacturing of abrasives is that the abrasive action is also exerted on the tool itself. Let us take flexible abrasives as an example. In this category of abrasives, the abrasive substance is sprinkled on a backing, which is normally made of paper or a polymer material. In order to obtain the desired shapes, such as a rotating disc or wheel, tools such as dies are used, i.e. a mechanical method that uses contact between parts to separate an element from the die into the desired shape.

Operations such as die cutting of abrasive materials, however, have a drawback. The abrasive action is also exerted on the cutting tools. Blades, dies and cutters quickly get worn out and must be replaced frequently to maintain high machining quality. This increases machining costs, which consequently increases the cost of the final product.

Laser cutting of abrasive materials overcomes this disadvantage. It is characterised by a total absence of contact. The laser beam interacts remotely with the surface of the material in a non-mechanical process that avoids the problem of continuous wear of the machining tools.

2. Laser is a versatile tool

A major disadvantage of traditional machining methods is also their lack of flexibility. For example, a die made to create a specific shape can only be used to create that specific shape. To make differently shaped parts, it is necessary to create new diecuts, provided that the investment required to create them is justified by a profitable return.

Similarly, only one machining operation can be performed with traditional machining tools. A die-cutting tool can only perform one machining operation. A cutting tool can only perform cutting. To perform different machining operations, one must change the machining tool. If a manufacturer wanted to apply information to an abrasive disc such as grit size or a serial number, he would have to insert the part into a dedicated machine, such as a printing machine.

Laser systems, on the other hand, allow several machining operations to be performed in a single session. With the same system, flexible discs can be cut from a die, cuts and perforations can be made and surface information on a material can be added through laser marking. In addition, the use of lasers allows the shape or size of the piece being manufactured to be changed in real time, without any additional aids. It is precisely its high flexibility that makes the laser the trump card for this type of application.

Laser offers a true change in the very way production is understood. It gives manufacturers the possibility of enormously expanding their commercial offerings. It becomes possible to create prototypes, just-in-time production, or series of small parts for high-value customers.

3. Laser is a precise tool

Abrasives are used in many different industries. Each of them requires specific processes, and, therefore, abrasive tools that are shaped differently. This means that there are more or less specialised tools: from simple sandpaper, sold in rolls and used by carpenters and craftsmen, to customised rotating discs for high-precision machining.

However, mechanical machining tools have a tolerance limit beyond which they cannot go. The size of the machining tools, their design, and the need to avoid unwanted contact limit the complexity of the machining that can be performed.

Laser, on the other hand, allows very tight tolerances. Since there is no contact between the parts, the tool can follow intricate cutting paths, create microscopic perforations and special shapes, make surface cuts and other machining operations that would be impossible with mechanical cutting tools.

4. Laser reduces machining waste

With traditional machining tools, processing is performed by the mechanical removal of material. The process tends to produce machining waste, dust and other residues that must be managed in some way, with a variable economic and environmental cost.

Laser machining processes, on the other hand, tend not to produce waste. Material removal occurs through sublimation. The very high energy density produced by the laser on the surface allows the temperature of the material to rise, instantly vaporising it as a result of a transformation of the material state.

5. Laser respects materials

Mechanical machining processes present a risk of damage to products due to accidental contact or excessive mechanical contact. Any deformation lowers the quality of the final product.

In laser processing, there is no risk of damage from mechanical contact. Laser processing respects all materials, even the most delicate ones. They guarantee a higher quality of the finished part and are therefore ideal for the sectors in which the degree of error must be kept down to a minimum.

6. Laser is an environmentally friendly process

Laser processing offers high energy efficiency. All things being equal, laser performs the processing with much lower energy expenditure than mechanical processing. This, combined with the absence of waste, makes the laser one of the most environmentally friendly processing tools available to manufacturers.

Contact us

Laser is a cost-effective tool for the manufacturing of abrasive materials. Because the possible applications are numerous, seeking the advice of an expert can help you find the most suitable processing system for your application. El.En. CO2 laser systems are ideal for the manufacturing of abrasive materials. Contact us for more information.

CO2 laser and fiber laser are the two most widely used types of laser in the industry sector. Both technologies have proven to be reliable and efficient. They offer high productivity, flexibility of application and accuracy of results.

But no two lasers are the same. The difference between these two technologies lies in the length of the laser beam. For fiber lasers, the typical wavelength is 1064 nanometres, while for carbon dioxide lasers it is 10.6 micrometers.

This difference in wavelength is substantial because it influences the type of material that can be processed.

Fiber laser, the king on metallic materials

Fiber laser is mainly used in metal applications. Fiber technology enables higher energy densities to be achieved on the surface of metals for two reasons. The first is that metals absorb the wavelength of the fiber laser well, whereas they tend to reflect and scatter the wavelength of the carbon dioxide laser. The second, is that fiber laser allows a smaller focal diameter on the working surface than the carbon dioxide laser. As a result, the fiber laser achieves a higher energy density for the same power than the CO2 laser.

The main shortcoming of fiber laser technology is its lack of flexibility. The wavelength of the fiber laser is absorbed well by metals, but not only. A limitation of the fiber laser is that many materials absorb its wavelength. This makes it difficult to select which materials the laser should affect, especially on multilayered materials.

CO2 laser, the most versatile laser

Selectivity is one of the advantages of the CO2 laser. The 10.6 micrometer wavelength is absorbed well by all carbon-based materials. These include most of the materials used in manufacturing processes.

Below are some of the materials on which the carbon dioxide laser is most efficient:

• Plastics and polymers in general
• Wood and wood-based materials
• Paper and cardboard
• Biological materials

These materials absorb the wavelength of the CO2 laser very well, which makes these laser sources very efficient in their processing.

CO2 laser vs. fiber laser for laser engraving

Laser marking and laser engraving are two variants of the same process. In both applications, laser technology is used to remove a layer of material. In laser marking, the laser removes a very thin layer of material. The mark produced is therefore superficial. In engraving, the laser goes deeper, removing a greater layer of material. The mark is therefore deeper and can often be felt by touch.

Both carbon dioxide and fiber lasers can perform marking and engraving. Based on what we have previously said, it should be obvious that the main difference lies in the materials on which the processing is applied.

As far as fiber technology is concerned, marking and engraving is mainly used for product traceability, i.e. to indelibly engrave identification numbers, serial codes or data matrices on metal parts. The high energy density and small focal point make it ideal for this type of application on metal materials.

Marking and engraving, on the other hand, is one of the most widely used processes of the CO2 laser. This process has a wide variety of applications. In addition to the simple marking of identification codes, CO2 laser achieves more sophisticated decorative patterns, so much so that it is used in the fashion industry. One of the applications that has been developed in recent years is, for example, laser marking of denim fabric for the production of jeans.

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El.En. Laser is a company that specializes in the production of CO2 lasers. Since 1981, we have contributed to the development of this technology, which has become a great asset to the industrial sector. We produce CO2 laser sources, laser scanning heads and laser systems for Industry 4.0. Contact us for more information or to get a consultation on how to build the right laser system for your business.

Laser magnet wire stripping is one of the many applications of the laser ablation process. This process is used in the most technologically advanced sectors. In contrast to conventional stripping, laser stripping works precisely and selectively. This makes it ideal for sectors where precision and quality workmanship are necessary.

What is a magnet wire?

A magnet wire, enamelled wire or winding wire is a copper or aluminium wire covered with a thin insulating layer. Its main field of application is in the production of conductive material coils. As you can imagine, the insulating layer is used to prevent the coil from short-circuiting simply by contact between the wires.

In order to do this, manufacturers immerse the conducting wire in a bath of polymeric material which completely covers it. The thickness of the insulating layer can range from 0.08 mm to 1.6 mm. Depending on the temperature at which the enamelled wire is to operate, the insulating layer can be made of different materials. The most commonly used materials are polyester, polyurethane and polyamide, in various formulations.

The enameled wire stripping process

Enamelled wire coils have a wide range of applications. These components are fundamental in the production of devices such as inductors, transformers, electromagnets, pickups, actuators, etc. In some cases, manufacturers may need to remove all or part of the insulating layer. One reason, for example, might be to solder the coil to larger components, or to make special connections in the circuit. To achieve these results, the enamelled cable must then undergo stripping operations to remove the insulating layer and enable it to operate.

The stripping process can be done using four techniques:

• Brushing
• Chemical process
• Stripping with blades
• Thermal process

Let’s go over them one by one.

Brushing

This technique uses rotating fibreglass or steel brushes. The fibreglass brushes rotate at high speed, produce friction and thus heat, and the heat melts the insulation layer. A smooth and polished surface is achieved.

The rotating steel brushes work thanks to the sharp action of the steel bristles. The result is a rougher surface. Because the brushes have a greater abrasive effect, they are used for larger surfaces where greater force is required for welding.

Chemical process

This technique involves immersing the enamelled wire in a chemical bath with a solvent action which dissolves the insulating coating. The coil is then cleaned to remove oxides and any residue.

Stripping with blades

This type of stripping uses rotating blades which, by moving at high speed, remove the insulating layer from the electrical cable.

Thermal process

In the thermal process, heated blades are used to melt the insulating layer. The heat combined with the movement of the blades removes the insulating layer from the enamelled wire.

The laser magnet wire stripping process

Laser stripping of enamelled wire is a viable alternative to these techniques. In this application, a laser ablation process is used to remove the insulating layer from the surface of the electrical cable.

The laser easily interacts with thermoplastic polymers. Compared to traditional removal methods, the laser has some important advantages:

• It is selective, the laser only interacts with the polymeric material and not the metal.
• It is precise, the laser can intervene extremely precisely on specific points on the surface.
• It is a green, unlike other techniques, laser stripping does not produce any processing residue.

All these advantages make the laser stripping technique ideal for cases in which material removal needs to be done in an extremely precise manner, typically in high-tech applications.

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Would you like to develop a laser stripping application for enamelled wire? Contact us: our engineers will study the right application 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!