Laser perforation process that can be used for flexible packaging

For decades, bags and pouches of all kinds have conquered the packaging market. Flexible packaging adapts to the shape of the object it covers, so less material is wasted. Laser perforation, also known as laser drilling, is a processing technology that allows the manufacture of new packaging designs that are both eye-catching and have advanced functional properties. Laser perforation is just one of many processing technologies that can be used for laser packaging manufacturing.

In general, the great success of flexible packaging is due to its functional properties. The main functions of packaging are, first, to protect and preserve the product, and second, to facilitate sales. Flexible packaging perfectly meets these two functions in an excellent way. Not only does it protect the product from external influences, but it can also be easily processed into a shape that best enhances the product's characteristics.

Here are some examples of the various shapes and configurations that flexible packaging can have:

• Stand-up pouches

• Heat-seal plastic bags

• Product sample envelopes for promotional purposes

• Pre-printed plastic film reel

This type of packaging is used in various industrial sectors. The food industry is one of the industries that uses it most often. Flexible packaging offers the best balance between weight, protection, hygiene and functional and commercial properties for the delicate products of this industry. Other industries such as the cosmetics, health and detergent industries also use them extensively.

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

• Plastic films - Polyethylene and Polypropylene are the main thermoplastic polymers used, which offer high insulating properties.

• Aluminum Foil - Aluminum foil is used when a high degree of protection from light or temperature changes is required.

• Polycarbonate     - These are created by combining materials from the previous two series to combine the advantages of both materials.

Laser Perforation for Flexible Packaging

As we have already mentioned, flexible packaging is finding wide application especially in the food sector. As more and more people live and work in cities and have little time to cook, the demand for fresh, ready-to-eat food is increasing.  

This type of packaging is most often used for products such as vegetables. In the fresh produce section of supermarkets, bagged vegetables have become the norm, a convenient solution for those who want to eat vegetables but don鈥檛 have the time to prepare them.

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

After harvesting, fresh food undergoes a series of biological transformations that are reflected in the release of gases, water vapor and chemicals inside the bag. As a result, strips are created inside the bag that are not suitable for the preservation of the product    

What is laser perforation?

Laser perforation can overcome this problem. The holes in the surface of the packaging paper can optimize the gas exchange between the internal and external environment. It is then easy to maintain the optimal conditions for better preservation of the product.

This technology is part of the laser cutting process. In this application, laser technology is used to form holes in the material. The most remarkable aspect of this process is that it can define the characteristics of the holes very accurately, from their diameter to their shape. This gives the process a considerable advantage over traditional packaging methods. Previously manufacturers had to find the most suitable packaging already available on the market, while with laser perforation they can customize the packaging to ensure optimal product preservation.

Benefits of Laser Perforation

Laser perforation offers many advantages over traditional flexible packaging perforation methods:

Precision: As with all digital processes, laser perforation offers all the precision that comes with using software. Therefore, even within the same process, the size of the hole can be changed according to a wide range of parameters.

Material Protection: Laser technology minimizes the possibility of accidental damage to plastic film materials.

Automation possibilities: Laser perforation is a fully automated process. It can be integrated into existing production processes to achieve full automation and improve manufacturing quality for the entire production line. It can be used for roll-to-roll or sheet-to-sheet processing.

Flexibility: Different processes can be performed with laser technology within the same production cycle. The same machine can perform several processes, for example, perforating plastic films and marking product traceability information.

What materials can be laser perforated?

The best results with laser perforation are obtained with plastic films. Most thermoplastic polymers absorb the radiation of a CO 2 laser very well and are therefore well suited for this type of processing. As we have seen, polyethylene and polypropylene are the materials with which the best results are obtained. On these materials, the cutting edge is perfectly defined and the processing is precise and clean.

How a Laser Perforation System Works

Choosing the right laser perforation system among the many options available on the market depends on the material used, the type of application and the ultimate purpose of the project. However, we can identify some constants in all systems.

A laser perforation system usually consists of 2 components:

CO2 laser source: This is the device that produces the laser beam.

Scanning head or focusing head: The laser scanning head is the device that moves the laser beam over the surface. In this way, the perforations can be distributed over the surface according to the production needs. This smart tool uses an integrated control software and can follow any type of pattern. For simpler machining operations, the system can be replaced with a focusing head, which has no control system but allows the laser beam to be focused on a specific point that can be moved in one or two axes according to the requirements.

This combination of basic elements can be integrated into an unlimited range of systems, from industrial in-line systems to stand-alone machines that carry out processing on their own. The laser system can act to move material from reel to reel or onto sheets of material.