The unstoppable growth of organic food sales seems to suggest that consumers are increasingly aware of genuine, natural, and environmental friendly fresh products. Organic food is realized in compliance with natural cycles, isn’t treated chemically, and is environmental friendly.

The trend involves all aspects of the product: from the cultivation carried out according to natural principles, to the packaging – designed to be the least polluting possible. It is exactly this last aspect that has seen significant innovations during recent years due to the development of the laser technology.

Creating eco friendly packaging is a hot topic of discussion at the moment. The goal of CO2 laser marking fresh fruit is not just reducing plastic consumption by replacing it with packaging materials such as recycled paper. The aim is – whenever possible, of course – to completely remove packing.

This is the direction some of the leading vegetable wholesalers are alreading moving to. Just look at ICA Gruppen, one of the world’s leading fruit and vegetable manufacturers. This company has already started adopting laser technology to replace traditional labeling methods. The label is directly laser-marked on the skin or peel of products. This simple transition translates into saving hundreds of kilos of paper and glue, resulting in an eco-friendly product.

But there is more: laser marking fresh fruit and vegetables also allows to improve the quality and genuineness of products. Several studies have shown that laser labelled products maintain the qualities of the original product. Laser marking is solely executed on the surface of the peel and only in order to change the pigmentation of the food. The entire process is carried out in compliance with maximum hygiene requirements, making the technique ideal for the food industry. Above all, with the laser technology, there is no need to use adhesives or other potentially harmful substances.

For this reason the laser labeling of fresh-fruit and vegetables is the ideal technique for every manufacturer of organic food products. A completely ecological product can only be realized by avoiding all use of plastic, paper, or adhesive materials in the labeling process. At the same time, by laser marking fresh fruits and vegetables, the traceability requirements of the distribution system stay respected.

The following are the main advantages of laser labeling fresh fruits and vegetables:

• Offers the ability to mark an unlimited amount of simple and complex signs, including graphics and logos, codes of any type, as well as expiration dates and traceability codes
• Laser marks are permanent, stable, non-abrasive, insoluble in water, resistant to temperature and UV rays. Laser engraved labels cannot drop coincidentally and cannot be altered
• Laser marks are perfectly hygienic and therefore suitable for any type of food
• Laser marking is an efficient, highly flexible and fully automated technology
• Laser technology reduces the consumption of materials, and thus help saving economic resources
• Laser technology is eco friendly as it avoids the use of chemicals that can be potentially harmful to the environment and human health

These are just a few of the many advantages of laser labeling. Over the years El.En. has experimented with several laser applications in diverse sectors of the food industry – such as the labeling of cheese and the application of traceability codes on apples. Applications of the laser technology are endless: contact us and we will discuss the CO2 laser labelling solution that suits your needs

The clothing industry is the second biggest polluting industry, being just behind the petrol industry. To give you an idea of the massive impact the fashion industry has on the environment, consider this: it is estimated that 10% of world’s greenhouse gas emissions are generated by the textile industry.

The textile industry is all but harmless to the environment since its production processes consume a lot of resources such as water, energy and chemicals for the finishing process. This has led the industry to research more sustainable and eco friendly processes.

One of the most polluting phases of the production processes in the clothing industry is the finishing process, e.g. fabric decoration. Research shows that laser technology currently is the most eco friendly and sustainable application that can be used to decorate clothing and fabric. Not only did the laser technology stand out as a viable and efficient technology, but it also allowed designers to innovate products and designs.

To be honest, the use of laser technologies in the clothing industry is not entirely new, but dates back to the early 60’s. From that moment on, researchers noticed the diverse advantages of this technology, such as precision and lack of wastes. After years of research, experimentation and applications, the CO2 laser has proven to be the most suitable technology for the fashion industry. The use of the CO2 laser is beneficial in terms of design as well as in terms of the company’s resources. All desired designs can be achieved, with millimetric precision, by applying the very vast and efficient laser marking processes on the fabric. The energy efficiency and the running speed of a CO2 laser source are incomparably superior to any other traditional production technique, resulting in a significant decrease of energetic resources. Furthermore, the technology solely modifies the surface of the material – this means that there is no need for water consumption or polluting chemicals.

Laser engraving for fashion design does not know limits in terms of versatility. Nearly all materials normally employed by the textile and clothing industry can easily be worked by the CO2 laser. The technology can engrave or mark either natural or synthetic fabrics. Recent studies have also revealed that this technology is highly suitably for the discoloration of clothing, in particularly jeans cotton.

The CO2 laser is especially suitable for the clothing industry due to its particular wavelength, which is well absorbed by non-metals and organic materials as they are bad conductors of heat and electricity. This allows you to achieve optimal results while consuming the least possible amount of energy resources. Inks, chemicals, and solvents are eliminated and there is thus no longer a need for large amounts of water: the eco-sustainability of the CO2 laser is thus evident.

This is also demonstrated by a recent study¹ that analyzed the outcomes of laser decoration and innovative designs on wool and polyester fabrics versus decoration achieved by means of chemicals. The research paid particular attention to the weight, thickness, perspiration, thermal conductivity, and strength of the fabric after they had been engraved or marked. Both production methods have been tested with simple as well as complex patterns. The results have shown that the laser technology method performed better in all of the above named aspects, in comparison with traditional methods.

Besides that, the laser technology has also shown better results in terms of speed, precision, and resource consumption.

In conclusion, laser engraving for the clothing and textile industry is a more efficient, sustainable, and eco-friendly process than traditional methods of decoration.

¹Application of Laser Engraving for Sustainable Fashion Design, G.X. Yuan, S.X. Jiang, E. Newton and W.M. Au, Research Journal of Textile and Apparel 2013 17:2, 21-27.

Let’s continue our journey of discovery of the different CO2 laser applications for the packaging industry. In the past articles, we’ve already described how laser micro-perforation can drill accurate holes on plastic film to create packages suitable to preserve fresh food. Laser micro-perforation applications, unlike traditional mechanical micro perforation applications, offer speed, flexibility, and extreme accuracy.

In order to improve the shelf life of products, it is often necessary to continuously control gas exchanges between the interior and the exterior of a plastic bag. Laser micro-perforation allows us to tightly control these gas transmissions, allowing us to easily package fresh products as well as preserve their quality.

It is no coincidence that the CO2 laser has seen a broad application in this field. The packaging industry knows very strict production rules and specifications. Packaging must not only guarantee the quality of the product, but must also meet requirements in terms of mechanical strength, packaging hygiene, and food safety. Besides that, all requirements also have to be reconciled with an aesthetic appearance. Poor packaging could reduce the perceived quality of the product, and is thus a crucial factor in influencing consumer buying behavior.

In this article we’re going to describe another application of the CO2 laser: we will talk about sealing plastic food bags.

Conventional methods to seal plastic food bags

Why is the CO2 laser an innovative process for the sealing of food bags? To get an answer to this question we have to briefly discuss the traditional methods used to seal plastic food bags.

Traditionally the sealing of plastic food bags is a welding process achieved through the application of heat and pressure. In this process, two sheets of plastic film are joined and welded together. This process is mostly mechanical, meaning that parts of the machine have to be changed every time a different packaging process is executed, in order to meet the packaging needs of diverse products. Traditional machines are heavy, due to their working parts that need to be fastened securely.

A production line of this kind is not flexible, while food manufacturers may need to apply different packaging techniques within the same production cycle. This would mean that the manufacturers have to the change machine parts or perform other maintenance operations, which results in lower productivity.

Laser hermetic sealing plastic food bags

The process of laser sealing of plastic bags is part of the hermetic welding process of thermoplastics. The most commonly used bags in the packaging industry are transparent and made of polypropylene or polyethylene.

These materials absorb the 10.6 μ wavelength of the CO2 laser very well. The laser beam reaches the surface of the material to be welded thanks to a scanning head. Subsequently, the laser heats up the surface so as to reach the melting temperature of the material, allowing it to weld the two plastic films together.

The entire process is incredibly fast: the speed achieved with this welding method to hermetically seal plastic bags allow to seal dozens of pieces per minute.

What are the advantages of hermetic laser sealing?

The advantages of using a laser sealing system to hermetically seal plastic food bags are endless:

• You can change the shape and size of the packaging material to be sealed without the need for long breaks in the production flow. It is not necessary to create custom-made parts since the laser can be applied to any type of container and to any type of machining even within the same production cycle.
• The sealing can even be carried out on very thin plastic films without risking any damage to the material. This allows extremely accurate machining operations and reduces the amount of material used, and thus reduces industrial waste.
• The CO2 laser is compact in size and light in weight since mechanical parts or other bulky mechanisms are not required. The laser system thus fits well into production facilities with confined spaces.
• Like any other laser process, the welding of plastic bags is a non-contact process. This means, among other things, that it is aseptic, and thus perfect for the packaging of food products.

Required components for a laser system setup

You may ask yourself right now which components are required for a laser system set-up. It is difficult to define in detail the diverse components or elements that will be part of the system. Each customer has its own needs in terms of power, production speed, material to be treated, etc. However, it is possible to define the following three basic elements of a similar system.

CO2 Laser source

The CO2 Laser source generates the laser beam that will work your materials. El.En. CO2 laser sources are available in different output powers, ranging from 150W to 1200W.

Laser scanning head

The laser scanning head is a device that “moves” the laser beam while keeping it perfectly focused on the point that needs to be worked. El.En.’s scanning head executes this process at very high-speed thanks to the beryllium mirrors mounted on galvanometric motors.

Control Software

The advantage of laser processing is that the entire process is controlled digitally. Through the software, you can control all relevant machining parameters and perform on-the-fly changes without interrupting the process workflow.

Wood, paper, cardboard, plastic, PMMA. And also rubber, leather, metals, and ceramics: CO2 lasers can cut a great number of materials. For this reason, CO2 lasers have become the most widely diffused laser technology for laser material processing.

However, despite the wide use of the CO2 laser we receive a lot of questions on possible appications that can all be summed up by what materials can be cut by CO2 laser? In this article we answer to this question with a simple list of materials that can be easily cut with CO2 lasers (the links take to articles that examine each topic in depth): 

• Wood based materials
• Paper based materials
• Acrylic (PMMA) and other plastic polymers
• Leather and faux leather
• Natural and synthetic fabric
• Biologic materialAll industrial sectors that need to process these materials can thus use the laser CO2 for a faster, smoother, and more precise cutting process.

Fields of application

To go into the details, the following list displays the main applications of CO2 laser cutting, ordered by industry:

• Papermaking industry
• Cutting cardboard boxes
• Cutting paper and cardboard
• Stencil cut
• Decorations

• Woodworking industry
• The cutting of any kind, and thickness, of wood, especially Plywood and MDF
• Inlay fine wood
• Engravings of any kind

• Engravings and inlays
• Laser engraving and cutting methacrylate
• Laser engraving and cutting leather goods
• Laser engraving name and number plates
• Laser engraving and cutting textiles
• Laser engraving electronic components
• Laser engraving anodized aluminum and varnished metals. N.B.: the CO2 laser usually doesn’t cut metal but can label or mark them indelibly.
• Engraving of glass, marble, and stones
• Inlays on ivory

• Creation and Customization
• Laser cutting hollow punches
• Laser cutting for architectural models
• Laser cutting plastic, cardboard, or wooden displays.
• Contour and cut labels
• Personalizing gadgets
• Personalizing buttons
• Material machining for model making

The list above is just a short list of the many different materials that can be processed by the CO2 lasers: there are lots of other materials that can be cut with the CO2 laser. Research on the applications of the CO2 laser is still an ongoing process, of which experimentation plays an important role: only experimentation provides us with certainty about the possible applications. For this reason we invite you to contact us whereby the material you want to work is not presented in the above list. Together we will find you the solution that fits your needs!

Let’s continue exploring the applications of CO2 lasers. In this article we will be talking about acrylic and CO2 laser.

Acrylic, also known as PMMA or plexiglas is one of the plastic materials that can be laser processed with success. In particular, CO2 laser is the right to do the job.

What is acrylic and why it is so successful

Acylic was discovered in the 1920s. However, the material only really gained ground only after WWII as a cheap and effective replacement to glass. Easy to manufacture and process, rugged and flexible, acrylic has imposed itself as a successful material for a wide range of uses.

CO2 laser and acrylic

Acrylic is also known as PMMA. This acronym stands for Poly Methyl Methacrylate and refers to its chemical formula which includes atoms of carbon. For this reason acrylic materials responds very well to the wavelength of CO2 laser, which is 10.6 micrometers. At this wavelength, acrylic is opaque to CO2 laser, which is therefore absorbed very well by the material. This feature, coupled with low thermal conductivity and a relatively low sublimation point (300 °C), allows acrylic processing to be done quickly and easily. As a matter of fact, the fabrication of acrylic materis is one of the applications in which CO2 lasers give the best results.

Laser cutting acrylic

The main laser processing technique for acrylic is probably laser cutting. As se we have seen, the interaction between the laser and acrylic is very efficient. That means that when a CO2 lasers interacts with an acylic surface, the latter absorbs a large part of the energy conveyed by the laser, which is focused then on a tiny spot.

High energy on a very small surface means instantly vaporizing the material and as a result we obtain the cut. This process is called by sublimation of the material. Sublimation causes the material to evaporate and therefore does not create residues, making laser cutting an extremely clean process.

The end results of this process is extreme precision and quality. The cut has clean and smooth straight edges that don’t require further finishing.

The acrylic laser cutting process is also incredibly fast. Speed ​​is related to the thickness of the material and the power of the laser source. But whatever the thickness, the processing speed will be significantly higher than the mechanical cutting methods, even if it is a CNC method.

The possibilities of laser machining are endless and, ultimately, only limited by the designer’s imagination.

Do you need a laser cutting system?

At El.En. we have a long experience in producing laser systems for the fabrication of acrylic. We can design complete laser system or integrate our CO2 laser in existing laser. For whatever request or question you might have just contact us!

The fashion, decoration, and design sectors are generally very competitive. They require a continuous stream of products and models to be offered to the public. There is a constant search for new and original design which is capable of characterizing the designer, while at the same time being in the interest of the public. In fields like design, innovation mainly relies on the imagination of designers.

That is why introducing the CO2 laser as a decoration tool has been greeted with enthusiasm by the decoration industry. The laser allows remarkable flexibility and allows to overcome any limitation imposed by traditional decorative production processes. Especially in the ceramic tile industry the laser technology process has proved to be a great ressource. The introduction of the laser has allowed producers to deeply innovate the production processes, but has also allowed them to give space to the creativity of designers. Laser technology allows to reach quality standards that were previously unattainable, while at the same time saving ressources.

The CO2 laser decoration process of tiles is based on the removal of a superficial layer of the material. The system consists of 3 basic components:

• A CO2 laser source
• A scanning head
• Control software

The laser allows you to improve the quality of machining significantly. Thanks to the laser control software it is possible to obtain a level of control and detail on ceramic tiles surface which previously was deemed impossible using traditional decorative processes. Here are the main features of machining:

• Well-defined lines: The laser allows to obtain perfectly defined lines on the ceramics, unlike conventional mechanical methods.
• Very narrow angles: the tolerances made possible by lasers are very high. This means that even very complex designs can be easily realized.
• Almost photographic quality: By adjusting the laser parameters appropriately, such as power and speed, you can get a wide range of shades making the image surface almost photographic.

Another advantage of a laser based system is its versatility that made it possible to experiment and propose new prototypes very quickly. Manufacturing gets very easy thanks to laser technologies, a tool always at the forefront of innovation in design.

CO2 lasers are one of the most widely employed technologies in manufacturing. The technology is so flexible and powerful that it is installed on a large number of industrial machines, used in a wide array of sectors. CO2 laser sources are well renowned for their resiliency: a machine based on this technology insures thousands of hours of high quality work.

This type of laser still needs periodical maintenance work. Its weakness is a slow but inevitable loss of power.

Gas leaks, CO2 lasers’ weakness

Excessive gas leakage has consequences on the laser’s output. Its power will either decrease over time or be reduced drastically all of a sudden during operation. This phenomenon produces a reduction in the quality of operation: the laser beam becomes unstable and precision work is compromised. When that happens, laser maintenance is necessary.

Maintaining CO2 lasers

Maintenance can be done by the producer or by a company specialised in this sort of operations. Generally, maintenance work includes disassembling the machine and refilling the gas tube. Many specialised companies offer this type of service, which often also includes the cleaning and realignment of the optics and other components of the laser source.

These operations, even when carried out by professionals, do expose the laser source to potential infiltrations of dust and other microscopic foreign bodies. This sort of infiltrations could compromise the laser beam quality and, as a result, the good working conditions of the machine. Transporting the machine to the maintenance service facilities can also expose it to accidental damage.

It is important to bear in mind that every maintenance will cause a standstill of production that can last from a few days up to a few weeks.

The advantages of El.En’s Self-Refilling technology: Never Ending Power

As a solution to the drawbacks of maintenance, El.En.’s research and development department has developed an innovative Self-Refilling technology. Thanks to Self-Refilling, gas-refilling operations can be carried out directly in-company.

The Self-Refilling system is based on disposable CO2 gas canisters. Every laser source has an in-built lid-protected slot for gas canisters. When it is time to refill the laser source, one needs to simply open the lid, take the empty canister out and put a new canister in. This way the laser source will maintain its max power and its operational standards will be preserved. Servicing operations can be carried out manually and without the laser source producer’s assistance.

The ability to independently refill a CO2 laser source brings about several advantages. Here are some:

• interruptions to production are reduced to a few minutes
• crucial parts of laser sources, such as the optics, stay sealed
• chances of infiltration of dust and foreign bodies are greatly reduced
• chances of damages from transportation are reduced

There are huge savings on resources and the laser source is always at max power and efficiency.

The Blade RF series of Self-Refilling CO2 laser sources are equipped with this innovative technology. These sources all have a compact design, come in multiple power options and can operate on a large variety of materials. Explore our range of products and discover the vast array of available applications.

Laser scoring is a wonderful technique to create advanced features on flexible packaging. Together with laser perforation it lets designer conceive easy opening packages, single portioned or disposable boxes, tear-apart openings that can enrich the experience of the product.

The rising success of easy to open packages has pushed producers to look for new packaging solutions. More than ever, consumers are used to easy-opening packaging.

The introduction of laser technology and digital converting processes has pushed packaging companies to find innovative solutions that were unthinkable of just a few years ago. Industrial lasers for packaging, such as the CO2 laser, give added value to a product by not only protecting it, but also making it easy to open.

Plastic film packaging, which has offered a wide scope for experimentation, is a perfect example of the added value of packaging.

As discussed in previous articles, CO2 laser can increase the breathability of the plastic film according to the product they contain. Fresh produce, for example, can be wrapped in micro-perforated bags in a modified atmosphere room to extend its longevity.

Laser scoring on plastic film bags to make packaging easy-to-open is another laser application that has many uses.

What is laser scoring?

A laser beam vaporises predetermined areas of a plastic film, thus creating the scoring. The weakening line that is created makes the packaging easy to open without the use of tools.

Laser incision has the advantage of removing the material in a precise and uniform way. This technique gives the possibility to closely control the depth of incision. By removing only the strict minimum amount of material, the integrity of the packaging remains untouched.

The right materials for laser incision

Laser incision is ideal for flexible packaging made in plastic film. These materials, which are some of the most commonly used in the packaging sector, are perfectly compatible with CO2 laser:

• polypropylene
• polyethylene
• polyester
• nylon
• multilayer films

Plastic film packaging can be used for all kinds of products: food, cosmetics, chemical products, herbal and pharmaceutical products.

Laser scoring technology

There has been a paradigm shift in the world of packaging since the introduction of laser technology. We have shifted from the mass production of standardised products to the small production of highly tailored products.

This change has only been possible because laser technology is a digital production tool. It can be completely controlled via software and is fully automated. A scoring laser system can be designed right from the beginning of the process and can work in analog work flows. Regardless of the type of work flow, laser technology brings added value to the production process, making it simple and fast.

Laser incision is a very versatile tool since the depth of incision can be controlled. By loading different vector files into the system, you can easily and quickly go from scoring to cutting through the material.

The laser can make incisions in a straight line, following the reel’s movement (down web?) or even transversally. The movement of the laser scoring is completely defined by the user. It can follow a straight line, the contour of a shape or a freeform path.

Laser technology is ideal for scoring because it is a contactless process. The lack of physical contact makes it possible to avoid problems such as the accidental rupture of the plastic film or the use of cutting tools. In order to achieve a high quality incision, the blades had to be perfectly sharp and therefore frequently changed. Production would to come to standstill in order to change machine parts which resulted in higher production costs.

The use of laser technology make all these problems obsolete. The only maintenance laser needs is a periodic gas refill. And now, with El.En.’s self-refilling technology which allows the laser source to be recharged autonomously, even this minor inconvenience can be avoided.

The right laser source for laser scoring

In conclusion, the CO2 laser is ideal for scoring of plastic film. The previously mentioned materials respond well to the CO2 laser wavelength. The laser scoring process works best with a low power laser source or with up to a 300 W power supply. One should also take into consideration that the higher the laser power, the faster the production.

The possibilities given by system integrations and configurations are endless. Once the type of application has been decided, it becomes easy to choose the best configuration.

• Introduction
• Laser labeling for food: fields of application
• The advantages of laser labeling
• Speed
• Precision and cleanliness
• Flexibility
• Environmentally friendly
• Indelible
• Laser labeling for food: the laser marking process
• The technology used in laser food labeling
• Laser food labeling: choosing the right laser source
• Laser scanning head
• A safe process
• A world to explore

Laser etching of various pieces of information on fruit, vegetables and other food products is an innovative procedure that is replacing traditional methods otherwise used in the field. A CO2 laser can not only etch alphanumeric codes and barcodes, but also any type of graphical representation.

This versatility can easily makes it possible to replace traditional methods such as hot-marking, inkjet printing and adhesive labeling. CO2 technology also guarantees huge savings in terms of speed and resources. Because of the previously mentioned reasons, there has been a growing interest in laser marking of food products.

In this article we will present a general overview of laser labelling for food. We will show its main fields of application, the advantages it delivers to both the production process and the environment, the way it works and the technologies employed.

Laser labeling for food: fields of application

Food products make large use of codes, labels and other varying symbols. They serve many purposes: guarantee the safety of consumers, trace products through the various steps of the supply chain and fight the counterfeiting of products. Here is some of the information you can find on products:

• alphanumeric codes like expiry date, batch code or PLU codes
• barcode or QR code
• logos and commercial brands
• controlled origin symbol

This information can be applied to the product in different ways:

• fire branding for products such as cheese or cured meats
• ink printing for products with non edible shells like eggs
• adhesive labels for fresh produce

The use of lasers in the food industry isn’t new. Production technology has long discovered the potential of this tool. Its use centered around process control (for example, reading barcodes), bio-stimulation of produce or disinfection of products through laser with ultraviolet wavelength.

The method of laser markings on produce to replace labeling has been known for several years. The first patent dates back to the end of the 90s. This process hasn’t yet become widespread though. The high cost of laser equipment combined to the lack of specific knowledge about the process has made most producer continue using traditional methods which are quite fast and inexpensive compared to laser.

In recent years, interest in laser technology has grown to the point that it is no longer only within the purview of specialists. Some famous companies in the produce sector have chosen to adopt direct laser labeling of their products. Many factors explain this shift from traditional labeling techniques to natural branding. The cost of laser technology has gone down in recent years while the demand for natural and organic products has risen. Companies strive to optimise resources and reduce the ecological footprint caused by their production.

The fact that European institutions have dedicated resources to this technology is a clear sign that this process has its advantages. In 2010, a European project for environmental innovation has explored the possibility to replace the adhesive labels on fresh produce with laser markings directly on the surface of the produce.

This technique focuses mainly on the labeling of fruit and vegetables but isn’t its only application. Aged cheeses can easily be marked by laser. In a recent article, we have discussed how laser systems can be used to engrave cheese wheels with identifying signs.

Another type of application mentioned in this blog is the laser impression of codes on eggshells. Tracing codes, expiry dates and laying dates are different pieces of information printed on eggshells. This data is fundamental to protect the health of consumers. Ink printing is the traditional method used. Laser impression efficiently replaces inkjet printing and makes it possible to avoid food products coming into contact with chemicals such as ink.

Laser markings can be done on a wide range of elements. Generally, the best results can be obtained on produce with some type of skin, be it thick like the avocado’s, or thin like the tomato’s. Up to now, laser markings have been successfully carried out on different types of produce. Here is a partial list:

• apple
• avocado
• banana
• grape
• lemon
• orange
• grapefruit
• mandarin
• peach
• bell pepper
• plum
• tomato
• watermelon
• melon
• chestnut

The advantages of laser labeling

Compared to traditional labeling techniques, direct labeling with laser markings provides a series of considerable advantages.

Speed

Laser’s most renowned characteristic is speed of execution. A laser source integrated in a system with a conveyor belt can mark batches of around ten items a minute.

Precision and cleanliness

Thanks to numeric control, it is possible to etch characters, codes and images in high resolution on the surface of products without leaving any type of residue. This characteristic makes it easy to ‘print’ QR codes, barcodes or complex logos.

Flexibility

Laser technology’s innovative characteristic is its versatility. A simple reprogramming of the laser control software is all that is needed during production to switch from one application to another.

Environmentally friendly

The use of many potentially polluting materials can become obsolete if replaced by laser marking. Plastic or paper labels, glue and ink can all be eliminated through the use of laser labeling. This would generate an important reduction of the ecological footprint. The products would then become less harmful for the environment or for the people that consume them.

Indelible

Laser markings are applied directly to the surface of the product and are therefore impossible to erase and difficult to counterfeit. This technique is perfect for products with symbols that guarantee their origin or quality.

Laser labeling for food: the laser marking process

Laser labeling is under the wider umbrella of laser marking, a process with multiple fields of application. Laser marking consists in the removal of a thin layer of the material’s surface. This delayering is caused by a thermal process triggered by the laser beam’s energy.

When the laser beam reaches the intended surface, it makes the temperature of the material rise until it causes its sublimation (the instant passage from solid state to gaseous state).

The removed material creates a well defined contrast between the untouched surface and the one marked by the laser beam. This process is renowned and used in many sectors on materials that aren’t destined for food consumption.

The technology used in laser food labeling

A laser system for food labeling is mostly identical to any other laser marking system. The fundamental components are:

• a CO2 laser source
• a scanning head
• a software for numeric control and automation

The design for the machine layout will naturally depend on the type of plant, processes and product used. A company that distributes and commercialises apples will need a different configuration to a company that does laser markings on cured meats.

Nonetheless, both machines will need a laser source, a scanning head that moves and focuses the beam on the surface of the object and a software connected to the control unit that constitutes the interface between the user and the system.

Let’s go over the characteristics these components need to efficiently carry out laser direct food labeling.

Laser food labeling: choosing the right laser source

Among the laser sources available on the market, CO2 lasers are the ones that show the best results when it comes to the absorption of organic material. These materials can efficiently absorb the infrared wavelength (10.6 micrometres) of a CO2 laser source because of their low thermal conductivity.

A laser source capable of keeping the laser’s parametres stable is fundamental in laser marking applications. This will guarantee a result with high levels of precision. In order to achieve this, the laser medium must remain in optimal conditions.

Sadly, it isn’t always possible. In the case of the CO2 laser, the medium is made of a gas mixture, of which the biggest part is carbon dioxide. Over time, the continuous leak of gas molecules makes the ones still present in the resonance cavity thin out. This causes a gradual degradation of the laser beam’s parameters.

Mutations of the laser beam will show through a lowering of work quality. Maintenance from the producing company is usually the only way to go back to the laser’s original parameters, but it means putting the production on hold and therefore increasing costs.

In order to avoid this inconvenience – which is typical of all CO2 lasers – El.En has created a autonomously rechargeable CO2 laser source. Because of this characteristic, El.En’s laser source can maintain the fundamental parameters of the laser at an optimal level.

Laser marking on produce doesn’t require such a great power. Nonetheless, the power of the laser source will have a direct influence on the speed of production so it is something to consider.

Laser scanning head

Every laser marking application needs a scanning head to operate. We have already seen in previous articles how a laser source works and what use it has. A laser scanning head’s function is to move the laser beam on a pre-established path that coincides with the processing of the goods.

A laser beam is a light ray that goes in a straight line until it reaches an obstacle of some kind. If a laser beam doesn’t get deviated in some way, it cannot be used in production. The laser scanning head’s job is to deviate the laser beam, making it follow a pre-established path.

The scanning head uses galvo mirrors to move the laser beam along the X and Y axes of a work area.

To function properly, the laser beam has to always be well focused on the surface of the processed product. A z-linear lense will increase and decrease the focal length of the lense and maintain the laser exactly where it needs to be.

The laser source and scanning head have to work in tandem. The laser’s position, focus, power and the duration of the beam have to be decided according the requirements of the production.

The software and control unit are responsible for the coordination of all these devices. The software is the interface between the machine and the user. It translates the patterns needed for production into coordinates and parameters that the control unit sends to the scanning head and laser source.

A change of the software’s parameters or the insertion of a new CAD file makes it very simple to engrave any type of information.

A safe process

When considering the use of laser technology, some people fear it might alter the shelf life of their produce. The skin does protect from mold, bacteria and other agents that could damage its organoleptic properties making it unsafe for consumption.

In the case of cured meats or cheese, the risk is minimal since the external crust is very thick. The laser markings only go a few microns deep and are much less invasive than the ones done with traditional methods such as firebranding.

Things could have become more problematic with fresh produce, especially fruits and vegetables with a very thin skin like tomatoes or grapes. The fear was that removing a layer of skin (however thin) would cause dehydration and various types of contamination.

In reality, many studies have shown that laser marking only touches the surface of the product and doesn’t provoke any alterations. The protective function of the skin isn’t compromised and the shelf life remains the same.

The organoleptic properties also remain unaltered and we can positively say that laser labeling doesn’t alter the flavour of produce in any way.

A world to explore

Laser marking for food products is a new world just waiting to be explored. Each product has different qualities and the parameters used should change accordingly. It is therefore fundamental to study a tailor made solution with the help of a laser producer.

In this article we will focus on one of CO2 lasers’ applications: laser heat treating of metals.

This type of treatment refers to the use of a laser as a heat source to be applied on a metal surface in order to make it more resistant to wear and mechanical fatigue.

There are several metals this operation can be applied to and results vary according to the type of metal or metal alloy. Laser heat treatment is used most on steel. This alloy is ideal for this type of treatment because of its carbon content and versatility.

Laser heat treatment can actually be divided into 3 diffferent types of processes: laser transformation hardening, laser annealing and laser surface melting.

In this article we will cover the first of these applications since it is the most widespread.

The way this process works

As opposed to traditional heat treating processes, lasers can be controlled with extreme precision. This makes it possible to contain the area and the depth of the layer that will undergo the heat treatment.

This characteristic is very useful in the processing of components subjected to mechanical or thermal stress such as, for example, cogs and mechanical components in general or work-related tools.

One of the most widespread applications on steel is the hardening process. It is caused by the transformation of the atomic structure of a layer of steel. More specifically, laser energy is applied to the surface followed by a rapid cooling. This causes a uniform diffusion of the carbon atoms which makes the surface more resistant to wear and mechanical stress.

Here is a partial list of metals on which the process can be applied:

• low-carbon steel (up to 0.30%)
• Medium and high carbon steel (up to 0.80%)
• Various types of steel alloy

As previously stated, the final results of the process are highly variable and, depending on the type of material, can either increase a metal’s resistance or pliability, or oppositely increase its ductility.

Before starting the process, it is therefore fundamental to analyse the metal’s content and understand the final use of the produced object.

Send us a message with your requirements and we will help you find the right laser solution for you.