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.

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.

Contact us

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

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.

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.

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. Contact us for more information!

Laser kiss-cutting

Laser kiss cutting (or kiss die cut) consists in removing the superficial portion of a sheet of material according to a specific cutting path. Unlike normal laser cutting, laser kiss cutting does not go through all the material but remains on the surface layer. Due to this characteristic, kiss cutting is mainly used in the paper converting and textile industries.

Laser kiss cutting is used when the superficial layer of a material made up of two attached sheets must be cut.

Laser die cutting of labels is an example of one of the most common applications of kiss cutting. The laser cuts out the surface layer into the shape of the adhesive to facilitate its removal from the support layer.

Laser kiss cutting can also be applied to the field of fabric decoration.

Kiss cutting for digital converting

Digital converting or laser converting is used to perform paper converting processes that would be difficult or impossible to achieve with conventional mechanical methods.

Laser kiss cutting is a typical digital converting application that, as previously mentioned, is particularly used in the production of adhesive labels.

This technique makes production particularly efficient and advantageous, since the costs and time required to set up the machine are eliminated.

In this sector, the materials most used for kiss cutting are:

  • paper and derivatives
  • polyester
  • plastic film
  • adhesive tape

Kiss cutting for the textile sector

In the textile industry, laser kiss cutting and laser cutting are used to decorate both semi-finished fabrics and finished garments. In the latter case, laser kiss cutting is very useful for creating personalized decorations.

This technique makes it possible to create different effects such as embroideries, appliqués and labels of various types.

Generally speaking, in this family of applications, two pieces of fabric are sewn together.

Laser kiss cutting then cuts out a shape on the surface layer of the fabric. The upper shape is then removed making the underlying drawing visible.

Kiss cutting is applied mainly on the following textile materials:

  • synthetic fabrics in general, in particular polyester and polyethylene
  • natural fabrics, especially cotton

The advantages of laser kiss cutting

The kiss cutting technique is not a modern discovery related to laser technology but dates back to traditional printing techniques.

Compared to these mechanical cutting methods based on blades and dies, laser kiss cutting offers several advantages:

  • the cutting path can be very complex, making detailed and precise cuts
  • the possibilities for customization are innumerable even within the same production cycle
  • it can be performed on a large number of materials without interrupting production
  • cutting tools don’t get worn during production which therefore eliminates the need for maintenance
  • speed, productivity and processing quality are at their maximum
  • edges are clean cut and defined and do not need further finishing

The industries of laser kiss cutting

As we have seen, laser kiss cutting is mainly used in the digital converting and textile decoration sectors.

Which laser systems are suitable for laser kiss cutting

Each laser kiss cutting application must be tailor made for each customer’s needs. In the label industry, a system consisting of a CO2 laser source and a scanning head is generally used.

The laser source

For the manufacturing of labels, high power isn’t necessary: most applications can be done with a laser source below 500W.

Keep in mind though that the power is directly proportional to the production speed. It is therefore sometimes necessary to resort to higher power because of production needs.

A small clarification on the source’s wavelength: El.En. has developed a CO2 laser source specially designed for label manufacturing, the RF333P, with a wavelength of 10.2 micrometers.

This wavelength is ideal for polypropylene (PP), of which is made the surface layer of most labels is made. This source is a variant of the Self Refilling series, which are the most suitable for paper labels.

The scanning heads

The scanning head always works in combination with a laser source. Its function is to move the laser beam on the work surface and keep it focused. To do this work the source uses mirrors mounted on galvo motors and a focusing lens on the Z axis.

El.En. produced a scanning head for CO2 lasers called GioScan. The machine is available in two models:

  • GioScan 1735, capable of operating on a surface between 135×135 mm and 800×800 mm
  • GioScan 1770HR, capable of operating on a maximum area of ​​2300×2300 mm

A laser system for each laser application

Laser kiss cutting applications are numerous and ultimately depend on the material and production needs.

The advantage of laser technology is that it is possible to create custom applications.

For over 35 years El.En. has produced laser systems for industrial applications.

If you have a production idea in mind that requires laser kiss cutting, send us a message and our team at El.En. will find a laser solution that best suits your needs.

What materials can be cut by a CO2 laser?

paper-cut-laser

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 laserIn 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!

CO2 laser lifetime

The CO2 laser has been on the market for many decades. Over the years it has proven to be a sturdy tool, capable of providing thousands of hours of processing without having to be serviced or replaced.

Unlike for mechanical production equipment, one of the biggest advantages of laser processing is low maintenance.

Mechanical tools operate by contact between parts and rely on moving mechanisms. The friction generated during machine operation makes wear and tear on this production equipment a pressing problem. Periodically, production has to be stopped in order to carry out the necessary maintenance operations, which increases the costs of operation and processing. The die sector is but one example of an industrial process that suffers from this problem. In this type of application, the dies have to be replaced periodically to guarantee the quality of the cut.

Laser, on the other hand, is a non-contact process. The entire laser system is based on the production and transmission of electronic pulses and the generation of polarised light beams. There are no moving parts or friction and therefore no direct impact on the lifetime of the laser source.

However, this does not mean that laser sources are maintenance-free. Laser sources also wear out, albeit much more slowly. This is why they need regular maintenance.

In the case of CO2 laser sources, the main problem is the rarefaction of the gas inside the laser tube. Year after year, the gas mixture is normally depleted, resulting in around a 1-2% emitted power decrease per year. This causes a gradual deterioration of the processing and a consequent decrease in efficiency.

The only solution to this problem is to periodically regenerate the laser source. However, this is a costly and time-consuming operation that usually involves stopping the production line, resulting in a negative impact on productivity.

El.En. has created a series of laser sources based on Self-Refilling technology to overcome this very problem. These sources, called Never Ending Power, avoid the regeneration of the source thanks to the use of a cylinder that contains the propagation medium. This cylinder can easily be replaced without causing any delays and guarantees the same process parameters and power over time.

This innovative recharging technology now makes it possible to have a laser source that always functions at maximum power. The laser beam’s quality will consistently remain at its highest level and the lifespan of the laser source will practically be infinite. Contact us for more information!

Glossary: laser cutting

Laser cutting consists in removing a portion of material from an object according to a pre-defined cutting path. This is one of the most common industrial applications of lasers: 80% of lasers used in industrial environments perform it. Laser cutting also includes processing such as laser drilling and laser kiss cutting.

The laser cutting process consists of concentrating the energy of the laser beam through a focusing lens until it becomes a very small point on the material’s surface.

Concentrating energy in such a way greatly increases its temperature and causes the removal of the material, hence the cut.

Based on the material being used and its chemical and physical characteristics, the interaction between the laser and the material will stimulate one of the following processes:

  • sublimation: the laser heats the material up to cause immediate sublimation. This process is used, for example, to cut different polymers.
  • melt shearing: the laser heats the material until it melts; the molten material is expelled by a gas jet. This process is used, for example, to cut metals and some polymeric materials
  • chemical degradation: the laser heats the material until its molecules are reduced to their essential components. This process is used, for example, to cut wood-based materials such as paper.

The advantages of laser cutting compared to other cutting methods

Laser cutting has numerous advantages both in terms of cut quality and in terms of very characteristics of the process. Here are the main ones:

  • very thin cut dimensions with very tight tolerances
  • clean cut edges without imperfections, and no need for further finishing
  • very restricted heat affected zone, does not damage the surrounding material
  • high cutting speed
  • due to lack of mechanical interaction, there is no need to fix down the piece being processed
  • there is no risk of tool wear and breakage as no physical means is used, the laser beam is made of light
  • process is easily automated
  • high possibility of customizing the cut and high flexibility
  • cleaning, reduction of waste
  • possibility to follow complex cutting geometries
  • no chips are made apart from dust, vapors or fumes that can easily be aspirated away

To learn more, read our articles on the main advantages of laser cutting.

Laser cutting industrial sectors

Laser cutting is used in many industrial sectors.

Here are some of them:

  • Automotive: cutting of plastic parts of cars, cutting of leather
  • Signage: design and production of innovative packaging
  • Display: cutting of LGP Backlight panels
  • Packaging: creation of innovative packaging
  • Food: laser cuts on food for consumption
  • Digital converting: paper converting
  • Decoration: creation of objects cut with laser
  • Fashion: creating special effects on semi-finished fabrics and finished products

Materials that can be processed with laser cutting

Laser cutting can be applied to most materials, commonly used in manufacturing. A distinction can be made between metals and non-metals.

Fiber laser is mainly used for laser cutting of metals. This type of laser works at a wavelength that is compatible with the characteristics of metals. For this reason, fiber laser cutting has become the standard for metal laser cutting. On the other hand, laser cutting of non-metals is in the undisputed realm of the CO2 laser. This type of laser has a wavelength of 10.6 micrometers which is perfectly absorbed by non-metallic materials. This characteristic gives the CO2 laser its extreme flexibility.

Here is a list of non-metallic materials that can be cut with a CO2 laser:

  • plastic film
  • PMMA
  • polyethylene
  • leather
  • natural fiber fabrics
  • synthetic fiber fabrics
  • wood and derivatives
  • mdf
  • chipboard
  • plywood
  • paper and cardboard
  • fruits and vegetables
  • meats and cheeses
  • vegetables
  • alumina
  • stone
  • glass

Laser sources suitable for laser cutting

For laser cutting, semi-sealed laser sources are generally the first choice. To obtain high quality cuts the laser system must have certain parameters.

An important parameter is the ability of the system to focus the laser on the work surface.

This parameter is determined by the performance of the scanning head. El.En.’s laser scanning heads make it possible to set focus parameters in such a way that high quality cuts are always guaranteed.

Speed and power of the source are two other parameters that influence the quality of the cut. For each application, the best combination can be found to obtain high quality results.

The speed of execution of the cut is directly proportional to the power of the laser. For high cutting speeds, a laser source with greater power is the better choice. The power can later be modulated when lower work speeds are required.

Laser sources can work in pairs with a scanning head or a cutting head.

The El.En. laser sources most suitable for laser cutting applications are part of the Self-Refilling Series.

This series was developed by El.En. with the following features:

  • never ending power: possibility to recharge the laser-producing medium on its own
  • different power options: available from 300 to 1200 W
  • same form factor for all powers
  • high energy efficiency
  • compact design

Get more information

As explained in this article, the feasibility of a laser cutting application depends on several parameters such as the scanning head’s focus capacity, the cutting speed and the power of the source all.

Each industrial process has its individual parameters that need to be defined. El.En.’s team of experts for over 35 years has been manufacturing industrial laser systems used all over the world. If you have an application in mind that could work with a laser solution, contact us and we will help you find the best solution for your process.

Laser micro-perforation of plastic bags for fresh products

micro-perforation-plastic-film

One of the characteristics of CO2 lasers is that it allows you to carry out processes which were impossible to perform beforehand, because of technical limitations in the past.

The CO2 laser has introduced new possibilities that have been exploited to meet market demands. One of these advantages is, for example, the laser micro perforation of plastic film. This technique has proven to be very useful for the packaging of fresh products before distributing them to mass retailers.

Micro perforated bags with laser for the packaging of fresh products

Laser microperforation is one of the newest methods to create micro holes in the packaging materials of products. To do this, the CO2 laser is used in pulsed mode. Unlike continuous mode, the pulsed mode sends high-intensity light flashes on the packaging material.

Laser micro perforation is particularly important for the packaging industry of fresh products. An increase in the demand of ready to consume fruit and vegetables, distributed via mass retailers, has led to the development of new strategies to ensure product freshness. Controlling storage temperature and modifying the atmospheric conditions within the packaging of products are the two most important factors for the quality of fresh products. The packaging thus has an important role in maintaining the freshness of the product, as it works as a regulator between the interior and exterior environment.

Laser micro perforation allows you to optimize the conservation of these products, through an improvement of the product packaging.

Objective: to improve the breathability of plastic bags

The packaging materials of fresh products in controlled atmosphere are often seen in the form of plastic bags. These bags allow optimal isolation of the products, and seal them perfectly from external contamination of molds or bacteria.

But there is a disadvantage: the breathability of these materials. Plastic film is a material that limits gas transmission with the exterior atmosphere. For a proper preservation of fresh products this is a significant disadvantage, as fresh products are subject to metabolic changes such as breathing, exchanging gases with the exterior atmosphere, and producing gas from chemical processes that take place within the fresh produce.

To improve the shelf life of a product, a continuous gas transmission between the interior and exterior atmosphere of the packaging is required. The levels of oxygen and carbon dioxide, play a big role in the conservation of the product. For this reason plastic bags must be perforated, in order to facilitate a proper gas flow between the internal and external environments. The amount of gas transmission required, however, differs from product to product. For this reason the perforation process must be properly adapted to the product needs. This aspect of adapting the perforation process, however, is difficult to achieve with traditional perforation methods.

Traditional micro perforation processes of plastic bags

Traditionally, the perforation of plastic bags is performed through two types of mechanical processes:

  • Heated or unheated needles: the plastic film is perforated by needles applied with or without heat. This process, though inexpensive, is slow. In addition, the holes produced have a larger diameter and can let contaminants, such as bacteria and mold, in. It is therefore not suitable for contaminant-sensitive products.
  • Electric discharge: packaging bags can also be perforated by means of electric discharge. The plastic film is passed through a high electrostatic voltage in which sparks are led through the packaging film to create micro holes. This process, even though faster than the previous one, is hard to manage. The hole parameters can not easily be checked. It is therefore unsuitable for those products that require precisely controlled gas transmission.

Laser Micro Perforation: accuracy in the service of the product

The machine that generates the best results in terms of micro perforating bags, turns out to be the CO2 laser. Micro perforation with the CO2 laser makes it possible to control the drilling process very accurately and obtain high quality results.

The CO2 laser is very well absorbed by most polymers and thermoplastics. The controlling software makes it possible to set the parameters to obtain holes of the required size and density, that let you create the optimum environment for gas transmission.