Is it really a feasible alternative?
Technologies - MU Sustainable Innovation
The subject is now widely debated in the sector, albeit still in a rather confused way.
All materials are biodegradable in the long run, it is only a matter of time. Even plastic bottles are technically biodegradable, but it takes centuries for it to happen. In the meantime microplastics and pollutants in many cases, will be released into the environment. If we recycle plastic bottles, we can recover polymers that can be reused for the production of new products.
What does biodegradability mean?
Biodegradability refers to the ability of organic substances and materials to be broken down into simpler compounds through the enzymatic action of microorganisms. In particular, according to EN 13432:2002, the degradation must involve at least 90% of the basic components of the material within 6 months in a carbon dioxide-rich environment. For composting, the time required is shorter - three months - and no critical substances must be released during the composting process by the degrading material.
However, this technological process, which cannot be entrusted to nature, takes place under controlled conditions and in the presence of microorganisms.
Does a supply chain exist that is today capable of collecting, separating, storing and biodegrading all the materials defined as biodegradable in the market? Currently, we have food residue composting and recycling of plastics and if we consider composite products, like a garment composed of different materials, some of which may not be biodegradable, we can easily see that there is still a long way to go.
Which materials are biodegradable?
Natural fibers and leathers are more likely to be biodegradable than manmade ones, provided that the materials have not been treated with chemicals which can slow down, or worse, pollute the environment during the degradation process. There are interesting cases also in the world of manmade fibers, because it is not necessarily so that even a bio-based polymer, i.e. a polymer produced from plants (e.g. castor beans) instead of from petroleum, will be biodegradable.
Below are the specifications issued by European Bioplastics, the European association of biopolymer producers:
- Biopolymers can partially or entirely derive from biomass and be biodegradable (PLA, PHA, PHB, starch-based plastics)
- Biopolymers can partially or entirely derive from biomass and not be biodegradable (e.g. bio-PE, bio-PP and bio-PET)
- Biopolymers may entirely derive from non-renewable raw materials and still be biodegradable (e.g. polymers used in packaging, disposable tableware and medical devices)
Research on biodegradable materials by producers evidences their intention to differentiate their products in terms of sustainability and reduce the carbon footprint generated by microfibers released during the washing of clothing items. These are important objectives that require utmost attention, analysis, experimentation and verification of the results obtained, along with scientific approaches that are becoming more and more common in the fashion industry.