The plastics packaging industry faces an eternal conundrum on sustainability. The hard fact is that high-barrier packaging, especially that which includes mixed materials like metallized films and aluminum foils, is almost impossible to separate into individual components or plies that can be effectively recycled. Compounding the problem is the fact that most flexible packaging (which constitutes over 70% of plastics packaging in India) is printed with proprietary designs and it becomes necessary to ensure that after-use waste is not fraudulently used or diverted into counterfeit products. Let us look at this problem in more detail.
The travesty of this situation is that there is absolutely no doubt that plastics packaging delivers such excellent functional properties, strength-to-weight numbers and economics that it not only optimizes the use of materials and their source reduction, it also has – by a whopping margin – the lowest carbon footprint. Innumerable studies and life cycle analyses have clearly established that plastics packaging is by far the best option for almost any application, and that people use plastics packaging without a second thought whenever they can.
On the other hand, after-use waste collection and segregation systems in our country are so hopelessly inadequate that even if suitable technology is developed to effectively recycle them, to put it into practice will be a monumental effort requiring a major overhaul. So, at the end of it all, all after-use packaging waste – especially those contaminated with food waste – goes into landfills and the material resource is just written off. Plastics packaging will continue to use the least amount of materials and incur by far the lowest carbon footprint but it will mean a gradual gnawing away of our finite stocks of non-renewable resources like fossil fuels and oil.
Compared to paper packaging (where worldwide recycling is 58%) and metal packaging (where global recycling is 70% – 90%), it is estimated that 95% of material value is lost for plastics packaging after a brief single-usage cycle. Although some segments like PET bottles have upped recycling into fresh bottles significantly, a lot of work has had to be undertaken. Initially, PET bottle waste had to be down-cycled into fibers used to manufacture garments or carpet backing because cleaning and recycling technologies were not developed well enough to ensure their reuse to make food-grade bottles. This has now changed to an extent where bottles made from PET bottle scrap actually deliver a lower carbon footprint than those made from virgin resin. However, this is an exception and plastics packaging recycling into equivalent value applications is virtually non-existent.
We need to seriously address this problem because, not only are we depleting scarce non-renewable natural resources, we are also running out of land for landfills; levies for landfills are also going up alarmingly.
So, what can we do to alleviate this problem? One option is to substitute inputs based on fossil fuels by those that are sourced from renewable resources like agricultural plants – bioethanol, paraxylene made from starches or sugars, new PEF resins based on agro-furanes amongst other possibilities. A lot of work is going on here and we have written about this in our last two issues. Other biopolymers like PLA and PHB are also being developed and improved all the time.
The other alternative to landfill disposal is to put the waste through waste-to-energy systems but this has to be done with extreme caution. Plastics have the potential to deliver a lot of energy. Their calorific value is exceeded only by fuel oils and fuel gases. However, indiscriminate incineration of plastic waste is extremely hazardous as the effluents generated contain noxious and even toxic gases. Unless the system is designed to capture and treat these effluents, the system will severely pollute the environment and cause more of a problem. Equipment for safe waste-to-energy treatment is available but is relatively expensive.
Technology is also available to convert mixed municipal plastic waste into sections by adiabatic extrusion for replacing wood used in applications like outdoor furniture but a major problem is that these sections cannot hold nails like wood can and complicated measures for fabrication will have to be developed and made suitable for use even by common carpenters. Of course, municipal bodies will still have to develop systems for effective collection, sorting and segregation of plastic waste.
Ultimately, we will have to develop new applications and markets for the use of post-consumer plastic waste or set up cascading of recycled plastics into new applications as described above for PET or cotton as described in our article on Circular Economies.
Again, the supreme travesty is that there is no material that is as endlessly recyclable into high-grade applications as a plastic, provided it can be cleaned and regenerated into pristine virgin-like quality. The plastics industry needs to aggressively address this conundrum given that plastics packaging is going to grow at a whacking rate and overall plastics consumption is expected to more than double in the next decade.
