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.