Helix of sustainability
Encyclopedia
The helix of sustainability is a concept coined to help manufacturing industry move to more sustainable practices by mapping its models of raw material use and reuse onto those of nature.The environmental benefits of the use crop origin sustainable materials have been assumed to be self evident, but as the debate on food vs fuel
Food vs fuel
Food vs. fuel is the dilemma regarding the risk of diverting farmland or crops for biofuels production in detriment of the food supply on a global scale. The "food vs. fuel" or "food or fuel" debate is international in scope, with good and valid arguments on all sides of this issue...

 shows, the whole product life cycle must be examined in the light of social and environmental effects in addition to technical suitability and profitability.

The helix of sustainability is a concept created as a representation of the total systems approach
Systems thinking
Systems thinking is the process of understanding how things influence one another within a whole. In nature, systems thinking examples include ecosystems in which various elements such as air, water, movement, plants, and animals work together to survive or perish...

 to gain full advantage from manufacturing with sustainable materials, particularly biopolymers and biocomposite
Biocomposite
A biocomposite is a material formed by a matrix and a reinforcement of natural fibers . With wide-ranging uses from environment-friendly biodegradable composites to biomedical composites for drug/gene delivery, tissue engineering applications and cosmetic orthodontics...

s. In 2004 the concept was presented by Professor John Wood, then Chair of the Materials Foresight Panel at a DTI event hosted by the then Secretary of State for Industry (Jacqui Smith
Jacqui Smith
Jacqueline Jill "Jacqui" Smith is a member of the British Labour Party. She served as the Member of Parliament for Redditch from 1997 until 2010 and was the first ever female Home Secretary, thus making her the third woman to hold one of the Great Offices of State — after Margaret Thatcher and...

). In the same year it was also used in the European Science Foundation
European Science Foundation
The European Science Foundation is an association of 78 member organisations devoted to scientific research in 30 European countries. It is an independent, non-governmental, non-profit organisation that facilitates cooperation and collaboration in European research and development, European...

 exploratory workshop on environmentally friendly composites.

The advantages of working with crop origin raw materials are readily observed if the social and environmental impacts are considered as well as monetary cost (the Triple bottom line
Triple bottom line
The triple bottom line captures an expanded spectrum of values and criteria for measuring organizational success: economic, ecological, and social...

), and the helix of sustainability helps to demonstrate this. For the full potential of biopolymers to be realised it is essential that attention is paid to every aspect of the manufacturing process from design (how to cope with the incertainties in properties associated with crop origin materials?), manufacture (can existing technologies be used?), through to end-of-life (can the redundant article be fed back into the materials cycle?).
The entire supply chain must be considered because decisions taken at the design stage have significant effects right through the life of an article. Low cost assembly techniques (e.g. snap-fits) may make dismantling or repair uneconomical. However, if say, an easy-to-dismantle car is built, will there be any effect on the ability of the vehicle to absorb energy in a crash? At an even more fundamental level, what will be the social and environmental of the change in crop growing patterns. This low environmental impact approach to manufacturing is seen as an extension of waste reduction techniques such as lean manufacturing
Lean manufacturing
Lean manufacturing, lean enterprise, or lean production, often simply, "Lean," is a production practice that considers the expenditure of resources for any goal other than the creation of value for the end customer to be wasteful, and thus a target for elimination...

.

Conventional cycles of use and reuse
Recycling
Recycling is processing used materials into new products to prevent waste of potentially useful materials, reduce the consumption of fresh raw materials, reduce energy usage, reduce air pollution and water pollution by reducing the need for "conventional" waste disposal, and lower greenhouse...

 are circular. Consider the mechanical recovery of conventional polymers. A complex infrastructure
Infrastructure
Infrastructure is basic physical and organizational structures needed for the operation of a society or enterprise, or the services and facilities necessary for an economy to function...

 is needed to recover the material at the end of an article's useful life. At the end of an article's life - say a PET
Polyethylene terephthalate
Polyethylene terephthalate , commonly abbreviated PET, PETE, or the obsolete PETP or PET-P, is a thermoplastic polymer resin of the polyester family and is used in synthetic fibers; beverage, food and other liquid containers; thermoforming applications; and engineering resins often in combination...

 carbonated drink bottle, the article must be separated from the waste stream, either by the consumer who throws it away, or by manual labour at the rubbish dump. It must then be transported to some facility to be reprocessed (using more labour and energy) back into a raw material. The heat and shear forces
Plastics extrusion
Plastics extrusion is a high volume manufacturing process in which raw plastic material is melted and formed into a continuous profile. Extrusion produces items such as pipe/tubing, weather stripping, fence, deck railing, window frames, adhesive tape and wire insulation.-Process:In the extrusion of...

 associated with the process of remanufacture tends to produce material with slightly degraded properties compared to the original material.

For sustainable material articles there is not such a great requirement for a dedicated recovery infrastructure. If a litter lout
Litter
Litter consists of waste products such as containers, papers, wrappers or faeces which have been disposed of without consent. Litter can also be used as a verb...

 throws a crop origin biodegradable
Biodegradation
Biodegradation or biotic degradation or biotic decomposition is the chemical dissolution of materials by bacteria or other biological means...

 article on the ground, it will ultimately biodegrade into humus, water, and non-fossil CO2. If the article is placed into a compostable waste stream, the humus can then be used as fertiliser for the next generation of crops, there is also no requirement to sort biopolymer articles as there is with fossil polymer recycling. Note difference between landfill
Landfill
A landfill site , is a site for the disposal of waste materials by burial and is the oldest form of waste treatment...

 and compost
Compost
Compost is organic matter that has been decomposed and recycled as a fertilizer and soil amendment. Compost is a key ingredient in organic farming. At its most essential, the process of composting requires simply piling up waste outdoors and waiting for the materials to break down from anywhere...

 - the limited biological activity in landfill is slow, and mostly anaerobic resulting in the production of methane
Methane
Methane is a chemical compound with the chemical formula . It is the simplest alkane, the principal component of natural gas, and probably the most abundant organic compound on earth. The relative abundance of methane makes it an attractive fuel...

, whereas composting is a rapid aerobic
Decomposition
Decomposition is the process by which organic material is broken down into simpler forms of matter. The process is essential for recycling the finite matter that occupies physical space in the biome. Bodies of living organisms begin to decompose shortly after death...

 process resulting in humus, water and non-fossil CO2. The energy bill for breaking down biodegradables into the fundamental building block molecules, and then reassembling them into usable raw materials is large, but is uses direct solar energy rather than metered electricity. There is also no loss of properties with successive journeys through the cycle.

See also

  • Waste hierarchy
    Waste hierarchy
    The waste hierarchy refers to the 3 Rs of reduce, reuse, recycle, or and [ which classify waste management strategies according to their desirability. The Rs are meant to be a hierarchy, in order of importance...

  • Industrial ecology
    Industrial ecology
    Industrial Ecology is the study of material and energy flows through industrial systems. The global industrial economy can be modeled as a network of industrial processes that extract resources from the Earth and transform those resources into commodities which can be bought and sold to meet the...

  • Mottainai
    MOTTAINAI
    is a Japanese term meaning "a sense of regret concerning waste when the intrinsic value of an object or resource is not properly utilized." The expression "Mottainai!" can be uttered alone as an exclamation when something useful, such as food or time, is wasted, meaning roughly "Oh, what a waste!"...

  • Biopolymers
  • Bioplastics
  • Non-food crop
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