Biofilms or organic films are regarded as a sustainable and environmentally friendly solution for the future, but it is important to look at the comprehensive process to be able to assess this objectively. Plastic films are designated as BIOFILMS if they are produced completely or partially from renewable raw materials (bio-based) and/or are compostable (biodegradable). In the following, we would like to clarify both the terms as well as the upstream and downstream consequences.
Biologically based films consist partly or entirely of renewable raw materials. The most commonly used raw materials are corn, potatoes or sugar cane. Not all bio-based films are necessarily biodegradable. In the meantime, developments have progressed to such an extent that, for instance, ethylene obtained from sugar cane can hardly be distinguished from petroleum-based ethylene, either optically or mechanically. In waste disposal, this "green PE" is therefore to be regarded as 100% polyethylene.
In cultivation of the above-mentioned renewable raw materials,CO2 from the atmosphere is bound by photosynthesis. At first glance, this reflects a CO2 balance that is up to 60% better than that of conventionally produced films. In the same comparison, however, the demand for fresh water is 2.5 times higher due to the crop management for bio-based films. In addition, there are emissions and energy consumption from agricultural machinery, the consequences of the expansion of monocultures, excess fertilization of fields, the clearing of rain forests and the use of food-grade plants as raw materials.
Biodegradability is defined in the EU by DIN EN 13432 and states that a material in industrial composting must have degraded to more than 90 percent to water, carbon dioxide (CO2) and biomass under defined temperature, oxygen and humidity conditions in the presence of microorganisms within six months.
Biofilms that are disposed of in German compost bins do not undergo a decomposition process in the usual two to three week collection cycle. As a result, a discarded organic bag is passed on completely intact to the recyclable material disposal. Except for a few exceptions, the sorting plants of the local recycling plants cannot differentiate between conventional films and biofilms. Therefore, both films are sorted out and passed on for thermal or material utilization.
Should biofilms nevertheless find their way through the sorting plants, they experience an industry-standard six to eight week fermentation process (e.g., in a bioreactor). However, compostable films must only have decomposed in 12 weeks according to the aforementioned European legislation. This is time they do not get in actual practice.
Are Biofilms more sustainable than conventional Films?
In conclusion, this question must be answered individually according to each person’s opinions and beliefs. However, full glorification of organic plastics is not appropriate.
On this occasion, we would also like to take the opportunity to dispel the widespread misconception that oil is being extracted exclusively for the production of plastics. 90% of the world's oil demand is used for heating, energy and transport. The proportion for plastic packaging is only 1.5%.
Reduce instead of renounce = Due to technical progress and intensive development work, the "down-sizing" of our POLYOLEFIN,POLYETHYLENE and POLYPROPYLENE films is progressing steadily. Feel free to contact us; we would be happy to advise you!