In consumer goods industries, packaging is considered a crucial factor in the consumer’s product experience. Yet difficulties in opening packages for anything from peanuts to sauces are surprisingly common, causing spills and even minor injuries.
The opening process often requires too much initial force and is hard to control because of missing or mechanically created opening lines. Rofin laser systems offer a more advanced solution because they can select individual film layers to scribe.
This allows for perfect easy opening functions while leaving layers intact that protect the product from light and humidity. Rofin lasers can even scribe freeform lines, e.g. following a contour on the print – a new inspiration for packaging designers.
Where perforation of packaging is required, easy ventilation functions created with Rofin laser technology are ideal: They increase the shelf life of perishables such as salad and other fresh produce, or control pressure exchange in microwave ovens.
Laser perforation lines can even create easy-tear-off applications. Unlike mechanical tools such as rotating knives or barrel punches, lasers work contact-free, suffer minimal wear and tear and offer excellent process integrity. Easy opening – selective weakening of flexible film.
Laser scribing is a method to apply easy opening functionality to multilayered materials for packaging. However, traditional tools tend to scribe too deep, damaging all layers and jeopardising product integrity, or too shallow, demanding too much initial force from consumers to control the opening process.
As a much more flexible solution, laser scribing can focus on individual film layers of composite packaging material.
Polymers like PET, PP or PE have different properties of absorbing and reflecting light at the CO2 laser wavelength. The absorption in one layer results in ablation while the next layer made of a different material stays 100% intact.
Aluminium or metallised layers, on the other hand, act as a highly reflective barrier to the laser light. All of this allows precise localisation of the desired scribing structures within composite packaging materials.
The easy opening function can therefore be applied without compromising the barrier or mechanical properties of the bag or pouch. The opening lines are clearly visible.
Opening the package becomes easy to control for the consumer. Moreover, laser scribing is a contact- and wear-free process that guarantees consistent quality and high process reliability. Easy Ventilation – micro-air-holes enhance shelf-life of food.
In perishable foods packaging, quality and shelf life depend on a balance between air circulation and preservation of humidity. For adequate perforation of the packaging, Rofin lasers offer significant advantages over conventional processes, such as needles or flame.
Based on 25 years of experience in laser perforation, Rofin uses CO2 lasers with high pulse intensities to perforate all layers of the packaging material. The micromelted edge of each hole prevents microfissures that could damage the packaging integrity.
Perforation is also suitable for pressure exchange function, like in packages for microwave meals. With strong packaging materials such as PE/PE combinations, laser perforation can even create perforation lines with 5 to 50 holes/cm for easytear- off applications.
Some typical products:
StarScribe Easy is a 100W compact turnkey CO2 laser system that can easily be integrated into existing production lines and winding systems. The flexible, articulated arm allows fast beam positioning with minimal additional effort. With one, two or four processing heads, StarScribe Easy lasers are a cost-effective solution that yields good results.
Used for scribing applications in web transport direction with lines that can be continuous, interrupted or synchronised to the print.
StarScribe Easy Remote
If higher laser power is required (e.g. for higher production speed) Rofin offers the StarScribe Easy Remote S/P with 100, 200 or 300W.
This is a high performance module, which can be integrated into existing slitters from all established manufacturers. Up to 8 processing heads allow simultaneous scribing.
High volumes of scribing structures in the web direction at web speeds of up to 600m/min are therefore possible. The system is powered by 100 to 2,000W laser sources and can also be used for film cutting or scribing with lines that can be continuous, interrupted or synchronised to the print.