Laser perforation for flexible packaging

Packaging

Bags and pouches of all kinds have been conquering the packaging market for several decades now. Flexible packaging adapts to the shape of the object it covers, so less material gets wasted.

The great success of this form of packaging is certainly due to its functional characteristics. If the main functions of packaging are to first protect and preserve products, and second, to facilitate sales, flexible packaging perfectly fulfils its role. Not only does it protect the product from external influences, but it can also be easily processed to give it the shape that best enhances the product's characteristics.

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

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

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

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

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

Laser perforation for flexible packaging

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

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

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

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

What is laser perforation?

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

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

The advantages of laser perforation

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

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

What materials can laser perforation be performed on?

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

How a laser perforation system works

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

A laser perforation system normally consists of 2 components:

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

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

Contact us

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