End Of Life
The use of flexible films allows companies to provide cost-effective packaging solutions coupled with excellent product protection characteristics. In this way all packaging films contribute to waste reduction throughout the packaged-goods supply chain.
However, the very nature of flexible packaging; lightweight and mixed materials, food contamination, inks, adhesives and difficulty in collection and sorting; renders conventional thermal-recycling techniques impractical.
This is where compostable films such as NatureFlex™ come to the fore. Standard NatureFlex™ films allow consumers to compost at home if they have a compost bin, or for local authorities to collect the films together with garden or food waste for industrial composting or anaerobic digestion, where such infrastructure exists. In those areas where incineration is the chosen method of residual waste management, NatureFlex™ is perfectly suitable and provides the same calorific value as wood.
Whilst recycling, anaerobic digestion, composting and incineration create value from the waste, landfill has no value and so is not a suitable option for the future.
Industrial Composting
Industrial composting is a controlled process for transforming biodegradable waste into stable products used in agriculture. It can be broken down into two distinct phases: active composting followed by curing. During the active phase, micro-organisms break down the organic waste into carbon dioxide (CO2), water and humus. Heat is also released and temperatures during this phase are generally between 50 and 60oC. During the curing phase, both the decomposition rate and the temperature decreases and humus is produced.
Common technologies include windrow composting, aerated static piles, tunnel composting and in-vessel composting.
All NatureFlex grades are certified to EN13432 and so are suitable for Industrial composting.
For additional information please see European Bioplastics Factsheet ‘EN13432 Certified Bioplastics Performance in Industrial Composting’ April 2015.
Ambient (Home or backyard) Composting
Whereas Industrial composting is a controlled process which allows the decomposition of organic waste under managed conditions with respect to temperature and oxygen, home composting refers to the cooler aerobic breakdown in smaller scale composting systems and is really closer to soil degradation.
In home composting, the ‘slow-stack’ technique is often used whereby organic matter is gradually added to the composting bin or vessel and over time this will naturally decompose to form compost.
Home composting is popular in countries where the number of homes with gardens is high and is suitable for garden waste and uncooked food waste. A number of bioplastic films are suitable for home composting, including the majority of NatureFlex grades, but certain films are not suitable due to the requirement of higher temperatures.
For additional information please see European Bioplastics Factsheet on Home Composting April 2015.
Anaerobic Digestion
In an anaerobic digester, organic matter is degraded by micro-organisms in the absence of oxygen and produces a mixture of methane and carbon dioxide and compost, but it is not an exothermic process. The biogas (carbon dioxide and methane) can be treated in a combined heat and power plant to produce electricity and steam, or it can be upgraded to biomethane.
Anaerobic digestion is suitable for organic waste with high moisture content such as kitchen or food waste and compostable packaging is able to facilitate or at least follow such organic recovery. Anaerobic digestion is certainly on the increase in UK following a Defra announcement to target 1000 new AD units in England and Wales by 2015, as AD is also an important player in the generation of renewable energy.
All NatureFlex grades are suitable for anaerobic digestion.
For additional information please see European Bioplastics Factsheet on Anaerobic Digestion April 2015, Anaerobic Digestion Strategy and Action Plan (DEFRA) and The Official Information Portal on AD (NNFCC).
Incineration (EfW)
The incineration of municipal solid waste exploits the energy content of the material and reduces the amount of material to be landfilled. The technology is also called thermal recovery or incineration with energy reclamation. There are two types of energy from waste systems: mass burn and refuse derived fuel systems. In the first case, the input is unsorted municipal solid waste and undergoes no pre-treatment. The latter is sorted prior to input and has a defined quality.
The Waste Incineration directive (2007/76/EC) was designed to prevent or limit negative effects on the environment, as this has been a cause for concern in the past. Very high temperatures must now be achieved to ensure complete combustion and there are strict limits on plant incineration emissions to air.
NatureFlex are suitable for incineration and will provide the same calorific value as wood.
For additional information please see European Bioplastics Factsheet Energy Recovery April 2015.
Landfill
A landfill is a burial site dedicated to the disposal of waste materials. Sanitary (or dry tomb) landfills are essentially sealed off to prevent the ingress of oxygen and moisture and to control the leachate and gaseous emissions. One of the major environmental impacts of landfills is gaseous emissions of landfill gas which occurs due to the biodegradation of organic waste. Certain types of landfill, called bioreactors, are designed to enhance the generation of methane which is collected and used as an energy source.
The Waste Framework directive (200/98/EC) requires Member States to develop strategies for waste prevention. Landfill is one of the least preferred methods of waste management in the hierarchy of waste treatment methods. It also states that measures should be taken to divert bio waste towards composting or digestion.
Testing has shown that bioplastic films, including NatureFlex, remain inert in a landfill situation and do not biodegrade due to the low moisture content present within a landfill environment.
For additional information please see European Bioplastics Factsheet Landfilling April 2015
Mechanical Recycling
Mechanical recycling is a method by which waste materials are recycled into ‘new’ materials which have the same basic structure. The waste material is sorted, either manually or automatically, to separate the different materials. The different material streams are then cleaned and ground, prior to re-melting and being formed back into granules. The resulting recyclates can then be processed into new products.
Mechanical recycling is a well-established technology for conventional plastics, such as polyethylene and polyester, particularly for rigid bottles. There is much less film recycling, partly due to the fact that flexible materials are light weight and so unfortunately have less value. In addition filmic structures are often multi-layer materials, which make separation of the different components difficult. Contamination is also an issue for mechanical recycling.
NatureFlex films are not suitable for mechanical recycling due to the fact that they are not thermoplastic materials.
For additional information please see European Bioplastics Factsheet Mechanical Recycling April 2015 and The Behaviour of Bioplastic Films in Mechanical Recycling Streams April 2015.
Paper Recycling
With concerns over plastics pollution and a desire to increase the recycling of waste packaging by either mechanical or organic recycling methods, Futamura is receiving an increased interest in laminate constructions using NatureFlex with either paper or carton board. To that end, Futamura commissioned testing of such constructions under simulated paper and board recycling methods.
Futamura does not claim that NatureFlex films are directly repulpable in their own right. The process that recreates the film from the raw wood-pulp destroys the fibrous nature of the wood-pulp and so additional fibre from the NatureFlex cellulose film will not be generated.
To determine the performance of NatureFlex/carton board & NatureFlex/paper laminates in the repulper, tests were conducted on paper-plates (where NatureFlex film replaced the plastic film on the top surface of the plate) and NatureFlex/paper laminates. In both cases standard dispersion techniques were used and complete separation of the NatureFlex film from the carton board and paper fibre was achieved. In both cases all the cardboard and paper fibre was released from the NatureFlex film. The NatureFlex film could then be fully recuperated as part of the standard filtration process.
The tests therefore confirmed that such NatureFlex-based laminates are suitable for collection and recycling in a conventional paper-recycling mill. More complex laminates were less successful through this route, but the amount of potential fibre to be recovered was <50%.
Laminates of NatureFlex with either paper or carton board can be certified as compostable subject to selecting the right grades of paper or board (i.e. certified to ISO17088, EN13432 or ASTM D6868) and completing disintegration testing on the finished laminates. Such constructions would therefore be suitable for recycling via organic-recycling methods, which is a benefit if the packaging is contaminated with food residues.