Single use for a multitude of services
Keeping dry with super absorbent polymers
Until he reached the age of fifty, nothing had motivated Vic Mills, a chemical engineer at Procter & Gamble, to take an interest in baby diapers. Upon becoming a grandfather, however, he considered making changing easier for his grandchildren, and saving his daughter from tiresome laundry chores! In 1958, with the company's approval and the help of volunteer mother, his first prototype of a disposable diaper was tested in Dallas. Unfortunately, the plastic used in the diapers was rather uncomfortable in high heat. After several trials and a few improvements, the diaper took off in 1961. And with success came a slew of competitors from both sides of the Atlantic who had more ingenious ideas to add to the product.
Adding polyacrylate to the cellulosic fibres was a decisive step in the improvement of the diapers. This super-absorbent polymer (SAP) in the form of a gel is able to absorb one hundred times more water than its own mass led to improvements on all fronts: in terms of efficiency, of course, but also in terms of size and comfort as well. It now comprises between 20 and 30% of all disposable products intended to fight incontinence. They are also comprised of 25% of other polymers such as polypropylene or polyester of the nonwoven films on the inside and outside of the diapers.
The large amount of synthetic materials in these hygiene products used at different stages of life now raises much criticism in discussions around waste management. This has prompted certain parents to start using washable diapers. However, no studies have highlighted any advantages of using such diapers, other than an economic advantage, of course. Although washable diapers produce less waste, they often have a disposable nonwoven layer, they lead to more water and energy being used. Disposable diapers come out on top in terms of recycling, however, like in Great Britain where Versus Energy and Knowaste, two industry heavyweights, have built the first factory recycling disposable hygiene products.
The plastic bag - The unbearable lightness of being
At its birth at the turn of the 1970s, it was poised for success. A weight of barely 5g of flexible polyethylene, able to carry a load 2,000 times its own weight, and unequalled resistance to degradation. All of this was available at a price per unit that was so low that shopkeepers everywhere started using it, both in the richest countries and the poorest!
Forty years later, this omnipresent object manufactured in a second now has the reputation of being a scourge that has destroyed cities and the countryside, threatens marine life and even the sacred cows of India!
A light bag can be such a drag
Around fifteen African countries have officially banned it, to no great effect. The less lax China has reduced consumption of plastic bags by 70% in six months during 2008. It is the subject of hundreds of restrictions in North America. Most European countries have taken similar measures at local or national level: taxation here, prohibition there...prior to the European Union trying to limit its use.
This is no easy task. Although Danish and Finnish citizens only use around one single use plastic bag per quarter, French and German citizens consume around two per week. In addition, citizens in most countries of Central Europe, Cyprus and Portugal use over one bag per day per citizen..
In the end, only heavy consumers will be affected by the new European directive adopted in 2015. The directive urges Member States to take steps to limit annual consumption to 90 bags per person by 2020, and to further limit it to 40 bags by 2026, or, failing that, to set a cost for using plastics bags by 2019.
However, some countries have shown more ambition in this regard, such as France which has decided to prohibit cashier bags in supermarkets from 2016. More problematic, however, is its decision to prohibit the very thin plastic bags found in the fish, fruit, vegetables and fresh meat aisles from 2017.
Biodegradation - a solution?
The alternative offered by biopolymers is very encouraging, despite the fact that their use still raises problems. Aside from their price, which is higher, their biodegradability can be problematic in humid conditions. In addition, these certified biodegradable plastics can only be degraded in composting plants, at a temperature of 57°C and a 90% humidity level. These are far from the conditions for home composting, at the bottom of the garden, soon to be required in France for the use of the ultra-thin plastic bags for fresh products.
Italy, which is at the forefront of bio-sourced plastics thanks to the Novamont Company, has chosen to support production by encouraging the distribution of compostable shopping bags to be used to recycle household waste. A problem remains, however! Shopping bags can be problematic when they have been filled with humid waste for too long.
In this context, the advances made by the Carbios Company in the field of programmed biodegradation plastics could make a difference. Especially given that its technology based on integrating enzymes into the polymers concerns more than simply biosourced plastics such as polylactic acid (PLA). Successfully tested on polyethylene (PET), the process is approaching the pre-industrial stage. It is poised to enable the biodegradation of plastics, made from fossil or vegetable carbon, to be controlled.
Plastics take a seat at the table
The fight against the pollution caused by plastic bags has caused some collateral damage. In 2007, Belgium introduced a 20% "picnic tax" on plastic plates and cutlery unsuited for home composting, and the former will now be prohibited in France come 2020. This decision amounts to forcing the de facto use of utensils made from biodegradable materials such as cardboard, wood or bamboo whose price and environmental impact are less advantageous. Or imposing the use of crockery that can be reused after countryside picnics and birthday parties.
However, it will be difficult to limit the use of disposables on other occasions. Disposables are useful and necessary for coffee breaks, lunch on the run, in hospitals and in airplanes for practical reasons or for reasons of hygiene. Their use can also be necessary for safety reasons too, like at prisons.
In this market where the volume of waste is significant although concentrated, preferring the use of biodegradable utensils makes little economic and ecological sense. Particularly, in the absence of composting systems. If waste is to be recovered, it makes more sense to recycle it! This is the thrust of the suggestion made by the American NGO Natural Resources Defense Council in its latest report on waste. The presence of significant amounts, around a quarter, of polyethylene and propylene in the utensils provided by fast food establishments are a deposit of recyclable materials highly sought after in countries that have recycling infrastructure. As for collection, it is made easier by the high concentration of such utensils in the places where the food is consumed.
