The world of films is in upheaval. As a result of stricter laws and social developments, the sustainability of materials for packaging in flowpacks is becoming increasingly important. There is no doubt that the future belongs to recyclable and compostable films. In order to remain competitive, manufacturers must adapt to this market trend on a permanent basis. This works best with a highly flexible flow-wrapping machine that can easily process a wide variety of films – not only plastic, but also paper-based.
This is more complex than it may appear at first glance, because the composite films used so far have numerous properties that are absolutely necessary for protecting the products and for automated packaging. Only very flexible, tear-resistant and easily sealable materials are suitable for use in a flow-wrapping machine. Additionally, the packaged goods must be protected from external influences by barrier layers in the film. Otherwise, durability and product quality cannot be sufficiently guaranteed.
The industry is still relatively in its infancy regarding the development of new materials. Currently, mono films made of plastic and the first paper-based films are being used. This is not possible with every packaging machine. But there is one that can already keep up: the Flowpacker! The flow-wrapping machine from Schubert packs with all three variants, i.e. composite films, mono films and paper-based films.
Films are becoming more and more sustainable. You can find out here which recyclable film is suitable when, and why a flexible flow-wrapping machine is future-proof.
- Composite films for cold-sealing and heat-sealing
- Recyclable plastic mono films
- Recyclable paper-based films
- Compostable films
- Cold-sealing and heat-sealing in one system
- Fast changeover for films and sealing technologies
Conventional forming shoulders have their limitations when processing paper-based films. This is because during packaging, the film is pulled over the forming shoulders at high speed and shaped into a tube. Both film and components are subjected to high stress. Paper-based films in particular are susceptible to tearing or wrinkling, and also wear down the material of the forming shoulders permanently.
Schubert therefore uses highly developed two-piece forming shoulders without any sharp edges. Hardened, coated surfaces are matched to various materials. The portfolio also offers forming shoulders that can be used for both plastic and paper-based films.
Each sealing technology is suitable for specific films and materials. Anyone changing the film therefore sometimes has to change the sealing technology. This is often not possible in conventional flow-wrapping machines, but is especially important for the use of recyclable films. This is because mono films made of plastic and paper-based films can be sealed very well with ultrasound, as the required sealing temperature is generated immediately and exclusively in the sealing layer.
Schubert’s flow-wrapping machines with unique heat-sealing technology can therefore operate with a combination of ultrasound and constantly adjustable cross-sealing times – ideal for recycled films. Additionally, the unique technology can be changed from heat-sealing to cold-sealing in a very short time.
Composite films consist of one or more plastic base films. PP, PET or PE plastics are frequently used, depending on the desired properties of the film. Barrier layers or blocking layers to protect the products from external influences as well as a sealing layer are also integrated into the film. Up until now, different materials have always been combined in a composite, it is almost impossible to recycle them by type.
Mono films consist of only one type of plastic in several layers and are therefore recyclable. A small amount of foreign material may be contained in the film. Usually this is the case with the barrier layer or blocking layer. PP (polypropylene) is usually used for mono films, as the films are thin and inexpensive, and the plastic becomes sealable with further processing. An additional sealing layer is therefore not required.
In the case of paper-based films, there are two types of packaging materials: recyclable packaging materials that can be reused in the paper recycling cycle, and compostable paper-based films. A small amount of foreign matter is also permitted in paper-based films in order to be able to integrate a barrier layer and a sealing layer. So far, paper-based films have only been used for pre-packaged products that tend to be dry to ensure shelf life.
Research is being conducted on compostable films with a higher barrier effect and on films made from other renewable raw materials. One example is cellophane, a pure wood product and therefore an entirely sustainable material. But ultimately, whichever film is successful on the market - Schubert is prepared to develop a suitable packaging machine.
The flow-wrapping machines with unique heat-sealing technology have a longitudinal sealing unit with ultrasonic and the flying cross-sealing unit with heat-sealing. First advantage of the Flowpacker: Ultrasound is exceptionally gentle and is suitable for recycled films. Second advantage of the Flowpacker: Sealing times can be set to within a millisecond on the cross-sealing unit.
If the Flowpacker is equipped with heat-sealing technology and a flying cross-sealing unit, the sealing times for cross-sealing can also be set to the millisecond. For gentle sealing, long sealing times can be set for which lower temperatures are sufficient.
Every Flowpacker with heat-sealing technology and a flying cross-sealing unit can be changed over to cold-sealing in the shortest time. All that is required is to switch off the heaters and secure the mobile cross-sealing unit. Even older cold-sealing films can be processed well, as the splices are slightly preheated in the Schubert flow-wrapping machine in the longitudinal sealing unit if required.