From Die-Cutting to Digital Packaging: CO₂ Laser Finishing for Cardboard and Corrugated Converting

Packaging

From Die-Cutting to Digital Packaging

Cardboard and corrugated board are already among the most widely used materials for sustainable packaging.

They are recyclable, familiar to consumers and widely adopted in e-commerce, food packaging, displays, protective packaging and customized boxes.

But today, the real challenge is no longer only the material.

It is the production process.

Packaging manufacturers are increasingly asked to manage shorter runs, faster design changes, customized formats and functional features such as openings, tear lines, ventilation holes, scoring lines and variable marking.

Traditional die-cutting remains extremely effective for high-volume standardized production. It is fast, robust and well established.

However, when flexibility becomes critical, CO₂ laser processing can become a powerful complementary technology.

The main advantage is simple: no mechanical tool is required.

A digital file can define the cutting path, scoring geometry, perforation pattern or marking layout. This makes laser processing particularly interesting for prototyping, small and medium batches, customized packaging, late-stage design adaptation and functional packaging features.

The industrial value of this approach should not be measured only against traditional die-cutting speed.

It should be evaluated across the complete production workflow: tooling cost, setup time, changeover frequency, design flexibility and the ability to manage variable digital geometries.

This is particularly relevant for cardboard and corrugated packaging, where the same production environment may need to handle different board grades, thicknesses, formats and functional requirements.

For paper-based substrates, CO₂ lasers are particularly suitable because cardboard and corrugated materials absorb mid-infrared radiation efficiently.

Within the CO₂ laser family, the 9.3 µm wavelength deserves particular attention.

In packaging and converting applications, 9.3 µm radiation can provide a different interaction with cellulose-based substrates, coated papers, films and functional layers compared with the more common 10.6 µm wavelength.

This can be especially relevant when the objective is not only cutting through the material, but also controlling the energy input for scoring, perforation, kiss cutting, marking or selective layer removal.

In this sense, wavelength selection becomes part of the process strategy.

Laser power, optical setup, focal length, scanning speed and extraction remain essential parameters, but the wavelength itself can influence process quality, edge behavior and interaction with coatings or multilayer structures.

Technical literature on digital converting confirms the relevance of combining CO₂ laser sources with high-speed galvanometric beam delivery.

Public technical references also confirm that CO₂ laser cutting of corrugated board can reach industrially relevant speeds. In one technical study, a cutting speed of 100 m/min was reported when cutting 1 mm corrugated board with 700 W of CO₂ laser power. The same type of reference highlights one of the key advantages of laser processing in corrugated converting: flexibility, since changing the cutting geometry is mainly a matter of programming.

In our internal tests performed with an El.En CO₂ laser, corrugated cardboard cutting showed very promising results.

As a reference, on 3 mm cardboard, using approximately 350 W and a 3” focal lens, a cutting speed of around 35 m/min was achieved.

Further tests at higher laser power confirmed the potential of CO₂ processing across different cardboard thicknesses:

  • 3.0 mm cardboard: up to 1.75 m/s
  • 6.5 mm cardboard: up to 0.55 m/s
  • 9.0 mm cardboard: up to 0.50 m/s

These values should not be interpreted as universal cutting speeds, but as indicative results obtained under specific test conditions. The final process window must always be validated on the customer’s actual material and target edge quality.

The same laser and scanner platform can support different digital finishing operations:

Cutting for windows, openings, shapes and trimming.

Scoring for controlled folding and bending lines.

Perforation for tear lines, ventilation and easy-opening functions.

Kiss cutting for labels, liners and multilayer structures.

Marking for logos, codes, graphics or late-stage personalization.

This does not mean replacing every conventional converting process.

For very high-volume repetitive jobs, mechanical tooling can still be the most efficient solution.

The opportunity is different: traditional converting for volume, CO₂ laser processing for flexibility, and digital control for customization.

This is where galvanometric beam delivery becomes strategically important.

By combining a high-power CO₂ laser source with a dynamic scan head, the process can move from a fixed mechanical tool to a programmable digital workflow. Geometry changes, variable patterns and different finishing strategies can be managed through software, reducing the need for dedicated tooling and allowing faster adaptation to product requirements.

In this scenario, CO₂ laser processing fits naturally into the evolution of modern packaging production: not as a replacement for all die-cutting operations, but as a flexible platform for digital converting where speed, repeatability and software-defined geometry are key requirements.

As packaging moves toward shorter product cycles and more sustainable materials, manufacturing flexibility becomes as important as material choice.

Sustainability is not only about what packaging is made of.

It is also about how efficiently, flexibly and intelligently it is manufactured.

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Faux leather laser engraving

The synthetic leather market has seen exponential growth in recent years. Natural leather is becoming an increasingly scarce commodity, both for economic and environmental reasons. On the one hand, the need for finished products at ever lower prices limits the use of expensive raw materials, and on the other, animal and environmental issues are driving companies to choose eco-friendly solutions.

Synthetic leather is very similar to natural leather from both a technological and sensory point of view. Unlike natural leather, it is not a breathable material. It also needs a base layer, often made of cotton or other natural fibres.

The advantages of synthetic leather over hide are many:

  • production costs are very low
  • the production batches are very uniform
  • textures and effects that do not exist in nature can be produced
  • it is easier to cut and sew

Far from being a less noble alternative to the original material, synthetic leather is a practical and modern material. It can be successfully used everywhere traditional leather was, with the same aesthetic and technical results.

The composition of artificial leather

Synthetic leather is made up of two layers, an upper one that imitates leather and a lower one acting as a base.

The upper layer is composed of a synthetic polymer. The most used materials are PVC (Polyvinyl chloride) and Polyurethane (PU). The two materials differ slightly. Most synthetic leather is made of PVC due to its low cost and greater resistance. Polyurethane, a costlier material, is less frequently used even though it feels more like real leather to the touch.

The artificial leather base is in fabric which can be made from synthetic fibres, natural ones (usually cotton) or even natural-synthetic blends.

The role of the fabric base is very important. The mechanical properties of synthetic leather rely on the strength of its base. The lifespan of synthetic leather is in direct correlation to the one of the fabric base.

Can you laser engrave faux leather?

The answer is yes, you can. Due to its thermoplastic polymer composition, synthetic leather lends itself very well to laser processing, particularly with CO2 lasers. The interactions between materials such as PVC and Polyurethane and the laser beam achieve high energy efficiency, ensuring optimal results.

Laser marking and engraving

The marking and engraving processes are very similar. In both cases, the laser beam acts on the surface layers. The laser energy activates alterations which, depending on the intensity, can be more or less deep or radical.

In marking processes, the applied energy density is very low. The material’s transformations stay at a superficial level and are more aesthetic in nature.

In laser engraving, the applied energy density is higher and reaches deeper layers of the material. It therefore undergoes substantial chemical transformations. The marking is more visible and contrasted. The end result can have a tactile finish and even a natural texture.

Laser parameters

The system must be set according to certain parameters to achieve the desired laser marking or engraving effects. There is no universal rule one can follow to set the system. The correct parameters depend on factors such as:

  • the type of material used: polyvinyl chloride and polyurethane absorb energy differently. So the settings must be regulated differently.
  • the colour of the leather: light coloured leather is more reflective than a darker one. Dark leather therefore absorbs the laser beam better, resulting in greater energy efficiency and faster processing.

A correct laser setting will aim to achieve the correct energy density in order to obtain a clearly visible mark without damaging the material.

Laser Engraving Systems

Leather marking/engraving is one of the applications of galvo scanning. This category includes all processes in which the laser source is used in combination with a scanning head.

The scanning head distributes the laser beam produced by the source on the material’s surface.

Laser sources and scanning heads are available in different models depending on production needs. In order to make the right choice, it is necessary to know your particular manufacturing characteristics. Send us information about your production plant and requirements and we will be happy to design a tailor made leather laser marking/engraving system to suit your needs.

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Laser Die Cutting vs. Rotary Die Cutting: an innovative technique for the packaging industry

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The introduction of lasers in industrial processes has been a small revolution: the effectiveness and versatility of this technology has allowed us to significantly renew diverse production fields. Especially the die sector has seen radical changes over the past years due to innovations in laser technologies.

Die cutting revolves all around the cutting, drilling, and shaping low-strength materials such as paper, cardboard, rubber, fiber, and cloth. Die cutting tools are mainly used in the paper and packaging industry, and are known to be robust.

Traditional Die Cutting

The creation of a die is a process that requires a lot of time, specialized technicians, and materials. This tool is thus not economically advantageous for manufacturers with small production quantities or large production variations.

  • The creation of a die requires the following steps:
  • Engraving a wooden board, needed to support the die.
  • Cutting and folding of the steel blade, to be inserted into the incisions of the base.
  • Fixing the blade on the die holder

The entire process must be carried out with utmost precision, as the blade must fit perfectly into the incisions of the support table.

It is thus clear that the die can be preliminary used for large and standardized production volumes. Small production volumes, prototype designs, or customized processes are bound to have high production costs.

The CO2 laser – an efficient and accurate tool

Market segmentation and the need to meet diverse and customized processes have led manufacturers having to search for innovative solutions. The CO2 laser, due to its characteristics, proves to be the best and most efficient choice.

The high power stability and the particular wavelength of this laser make it the ideal tool to cut paper and cardboard, typical packaging materials.

These packaging materials have the following characteristics: low conductivity, high combustibility, low gasification temperature, minimum thickness. These characteristics make the perfect conditions for the CO2 laser. With these conditions the CO2 laser is known to have a high running speed, while maintaining minimal energy consumption

Each laser process is characterized by accuracy and speed. The laser path is managed by the computer that “translates” the CAD design of the project into parameters such as power, speed, and position. In this way the laser beam produced by the CO2 laser source reaches the surface to be worked, causing the immediate evaporation of the material and therefore the realization of the process.

This process allows you to make cuts, perforations and engravings – in short all the operations of a die – in a fast, precise and flexible manner.

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Label laser die cutting

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.

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Glossary: laser microperforation

Microperforation is a laser process that consists in creating micro holes on a sheet of raw material. Microperforation makes it possible to precisely choose the size, depth and quantity of holes per square centimeter. The flexibility of this technique makes it easy for the operator to change the processing characteristics according to the intended final use of the piece.

There are many examples of this processing technique from various sectors:

  • the paper industry where microperforation is used to create security paper, i.e. paper products with special features to make counterfeiting very difficult
  • the industry of fabrics and leathers, microperforation can be used to add decorative elements but also to improve the breathability of materials
  • a similar application is in the automotive sector, where for example, microperforation is used in the finishing of leather for the internal lining of cars
  • the packaging sector, microperforation is widely used. It is used to microperforate the plastic film used for packaging in modified atmosphere because the size and density of the holes can be adjusted with great precision
  • Finally, a last example comes from the field of soundproofing. Sound absorbing tiles that perfectly muffle a specific type of frequency, are made with laser microperforation

The advantages of laser microperforation

Microperforation has several advantages over traditional applications. Here are two:

  • Precision. Laser can perfectly calibrate the density, number, size and internal shape of the holes. Microperforation therefore allows you to create processes perfectly suited to the intended use of the product
  • Flexibility. Different materials can be processed using the same laser source. CO2 laser sources are unbeatable for their flexibility of use

What materials can be processed with laser microperforation?

CO2 laser microperforation works best on flexible natural and synthetic materials. Some of them include:

  • thermoplastic polymers, materials such as PMMA, polyethylene, PP and PET are among those most used in the packaging sector and suitable for this type of processing
  • leather and hides
  • fabrics made from natural and synthetic fiber
  • paper and cardboard

Which laser source to choose to execute laser microperforation?

There are many factors to take into consideration when choosing the right laser source for microperforation.

One must consider the material being processed as well as the desired production outcome and process speed. Based on these elements, it is possible to establish the best wavelength and the power to use to get the job done.

Although finding the laser solution that best suits your needs may seem impossible, don’t worry, our experts have extensive experience on the field and will be able to help you find the laser system that’s right for you. 

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Laser Engraving Fashion Design: a sustainable application

laser-marking

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.

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6 advantages of laser manufacturing abrasives materials

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.

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What plastics can be processed with CO2 laser?

Plastic processing was one of the sectors in which the introduction of the CO2 laser was immediately appreciated. Laser has made it possible to carry out faster, more precise and less wasteful processes.

Flexibility has been the watchword that made new methods possible andopened up new areas of application for plastic processing.

The word “plastic” is quite inaccurate: it covers a large number of materials which have very different behaviors, mechanical characteristics, workability and possible applications.

Cutting, drilling and marking are the main processes that can be carried out with CO2 laser. Plastic objects are cut by gradually removing the material until the laser beam penetrates through its entire thickness.

Some plastics lend themselves more to cutting than others. The best results with laser are obtained with acrylic (PMMA) and polypropylene (PP). On these plastics, the cut comes out with smooth, shiny edges and without any scorch marks.

CO2 laser marking for plastic is based on the same principle as laser cuts; though in this case, the beam only removes a surface layer, leaving an indelible mark.

In theory, laser can mark any type of logo, code or figure on plastic, but in reality, the possible applications depend on the material used. Some materials respond better to cutting operations, while others are more suitable for marking.

But what does this great variability of behavior between one plastic and another depend on? The difference lies in the different disposition of the monomers, the repetitive molecular units within the polymer. Variations in temperature have an effect on the material properties and behaviour.

In fact, all plastics are processed with the use of heat. Depending on how they respond to it, plastics fall into two categories: thermosets and thermoplastics.

Examples of thermosetting polymers are:

  • polyimide
  • polyurethane
  • bakelite

The main thermoplastic polymers are:

  • polyethylene
  • polystyrene
  • polypropylene
  • polyacrylic
  • polyamide
  • nylon
  • ABS

Thermoplastic polymers, up to a certain threshold (called glass transition temperature), behave like a crystalline solid. Beyond this temperature they first transition to a rubbery state and then finally melt. These polymers are made up of linear chains, which explains why they can be melted and easily molded at certain temperatures.

Thermosetting polymers on the other hand, stiffen as the temperature increases until they reach melting point, beyond which a change of state occurs. Cross-linking within the macromolecule, makes them less susceptible to temperature differences. Because of these substantial differences, not all plastics respond well to laser. In general, thermoplastics lend themselves better to laser processing, but even thermosets can, to some extent, be subjected to laser processing.

In the following tables we have summarized the result of the interaction between the various polymers and the laser.

Thermosetting polymers
Type of polymer Cutting quality Marking quality
Polyurethane Fairly good Poor
Bakelite Very poor Very good
Polyimide Very good Fairly good
Thermoplastic polymers
Type of material Cutting quality Marking quality
Polyethylene Fairly good Fairly good
Polistirene Fairly good Fairly good
Polypropylene Very good Fairly good
Polymethylmethacrylate (PMMA) Very good Very good
Polycarbonate Very poor Very good
Nylon Very good Fairly good
Polyvinyl chloride (PVC) Very poor Very good

As you can see, the results vary widely. A case by case analysis is recommended to understand which application works best. Plus, more plastics can undergo laser cutting: teflon (PTFE) is on of those.

How to choose the right laser system for plastic

The introduction of laser in plastic processing has paved the way for new applications. Laser processing of plastic is very convenient. Most commonly used polymers are perfectly compatible with the CO2 laser.

But choosing the most suitable laser system is not easy. The variables to take into consideration are many: the type of application, the type of material, and the production needs.

El. En. has produced laser systems for plastic processing for over 35 years. If you have an application in mind and aren’t sure how to make it, contact us. We will be more than happy to help you.

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Hermetic laser sealing of plastic food bags: what it is, how it works, and the advantages

Yellow pear in plastic bag

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.

Discover more about our El.En. laser solutions:

RF505RF555S35S20

Get in touch and find the perfect system for your application!

Contact – El.En. Laser

The wavelength of CO2 laser

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

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

Why the laser wavelength is key

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

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

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

The wavelength of CO2 laser

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

What’s your need?

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

Discover more about our El.En. Laser Solutions:

RF404G RF404

Get in touch and find the perfect system for your application! 

Contact – El.En. Laser