پنج شنبه 1 اردیبهشت 1401
بازدید : 494
تعداد نظرات : 0
Plastics Recycling and Sustainability
1) Overview of Plastics and Sustainability
2) Environmental Sustainability
- Packaging
- Construction
- Transport
- Waste Management
- Plastics Recycling
- Energy from Waste
3) Economic Sustainability
4) Social Sustainability
1. Overview of Plastics and Sustainability
In order for a product or material to be truly described as sustainable it must be environmentally, economically and socially sustainable. These aspects have become known as the Three Pillars of Sustainability. Plastics make a positive contribution to all three pillars of sustainability.
Plastics make an immense contribution to the environmental sustainability through their energy saving potential and intrinsic recyclability and energy recovery options. Economically plastics form an important part of the UK economy and are a major export product. Socially the plastics industry is a major and inclusive employer with an attention to training and education.
You can read more about the positive contribution of plastic here.
2. Environmental Sustainability
Plastics have a very good environmental profile. Only 4% of the world’s oil production is used for plastics and much less energy is used to produce it compared to other materials. Plastics are durable yet lightweight and thus save weight in cars, aircraft, packaging and pipework.
When plastics have completed their use phase, whether as a car bumper or a bottle, they can either be recycled or if this is not economic or environmentally beneficial the calorific value of the plastic can be recovered through energy from waste incineration to provide a much source of home-grown power. As a consequence plastics can be viewed as ‘borrowing’ the oil.
Packaging
Plastics provide unparalleled benefits as a packaging material. This is because plastics are lightweight, resource efficient and offer excellent barrier properties. Due to these properties packaging items in plastics significantly reduce waste and saves energy.
• Plastics packaging reduces waste
• On average, ten times more energy goes into the production of the food or goods packaging contains than the packaging itself.
• Food waste in UK is 2% compared to between 40 and 50% in developing world. This is due, in no small part, to plastics packaging systems
• A cucumber loses moisture quickly and would be unsaleable within 3 days were it not protected by 1.5 grams of plastic.
• Plastics packaging is lightweight and resource efficient.
• If plastics were not used in packaging and other materials were used instead, then waste and energy consumption would double, and weight and costs would quadruple.
• Plastics packaging has an excellent record of innovation and lightweighting. Between 1991 and 2000 the average weight of plastics film (g/m2) decreased by 36% whilst the average weight or bottles and containers decreased by 21%.
• Plastics packaging is recyclable.
• 21.8% of plastics packaging placed on the market in 2005 was recycled.
• In 2006, 6499 tonnes of EPS packaging was recycled in the UK. This represents 42% of EPS packaging manufactured in the UK.
Construction
Plastics have a huge role to play in sustainable construction, whether it be PVC windows, plastic foam insulation or plastic water pipes.
• If all buildings in Europe were to the optimal standards it would save 460 million tonnes of CO2 per year. Plastics foams provide excellent insulative properties and are very cost effective.
• The use of EPS, PU or melamine formaldehyde foam insulation saves energy. 1kg oil used to make EPS will save the equivalent of 75 kg oil for heating over 25 years of a building’s life
• Plastics pipes use less energy to produce than concrete or iron and since lightweight they save on transport costs and emissions in the building industry. Furthermore, the replacement of Victorian pipes in London, with new plastic pipes reduces leaks and saves significant amounts of water with consequent savings in the energy required to process and pump the water.
Transport
Plastics have a number of inherent properties which make them an ideal material for modern transport systems. Plastics are lightweight, corrosion free and easily moulded into complex shapes without the need for assembly or fastening systems.
Automotive
The average new car in 1984 contained 8.5% plastics by weight. A similar car today contains around 11%. The increased use of plastics reduces the weight of vehicles and consequently emissions. The weight reductions brought about though the increased use of plastics has also offset the extra weight brought about by improved safety features such as airbags.
Using 100 kg of plastics in a car can replace between 200 - 300 kg of traditional materials. Over the average lifespan of a vehicle every 100kg of plastics will reduce fuel consumption of the vehicle by 750 litre.
Aerospace
Some 22% of the Airbus A380 (the world’s largest commercial aircraft) is built from carbon reinforced plastics. This helps to reduce the fuel burn to a rate comparable to that of economical family car.
The fuselage of the new Boeing 787 Dreamliner is made from three plastic composite sections. This serves to reduce fuel burn by as much as 20%.
Rail
The use of plastic composite panels in Swiss trains has led to a 25% reduction in weight and consequently significant energy savings.
Waste Management
Plastics recycling takes place on a significant scale in the UK and there is considerable research conducted to discover the most efficient ways to recycle. Raw materials have a high value and are a precious resource, so to conserve both money and the environment the industry makes every effort to recover as much as possible.
There are two primary methods to recycle plastics, mechanical recycling and feedstock recycling;
• Mechanical recycling is the simplest method. Mechanical recycling is where the plastics, which soften on heating, are, reformed into moulding granules to make new products. The process involves collection, sorting, baling then size reduction into flake (film and sheet) or granules which may then need washing and drying. This is then re-compounded with additives and/or more virgin raw material, extruded and chopped into pellets ready for reuse.
• Feedstock recycling involves breaking down polymers into their constituent parts through the use of heat or pressure. In turn these parts can be used to make new plastics and chemicals. Feedstock recycling provides benefits when the materials are being recycled are mixed or contaminated.
An alternative to recycling is to recover plastics thermal content through energy from waste incineration, providing an alternative source of energy. The average value for polymers is 38 mega joules per kilogram (MJ/kg), which compares favourably to the equivalent value of 31 MJ/kg for coal. This represents a valuable resource raising the overall calorific value of domestic waste which can then be recovered through controlled combustion and re-used in the form of heat and steam to power electricity generators.
3. Economic Sustainability
Plastics take a major contribution to the UK economy and a healthy manufacturing sector is vital to a sustainable economy.
Plastics contribution to the UK economy:
• Circa 7400 plastics companies in UK.
• The industry turnover is approximately £17 billion.
• Plastics are a much need source of export revenue with circa £4.5 billion in exports.
• For many plastics products, especially construction related products, the whole supply chain is situated within the UK.
Plastics also have a role to play at a micro-economic level:
• Plastics products are very cost effective to produce and provide the ability to make single moulded components in complex shapes. This significantly reduces costs associated with assembly and the use of fixtures.
• Plastics products also provide whole life cost savings:
• Reduced fuel use in transit due to their lightweight.
• Reduced maintained requirements, for example PVC windows do not require painting.
• Reduced energy required for heating when plastics insulation is used.
• Reduced food and consumer goods wastage due to the unparalleled protective properties of plastics packaging.
• The plastics industry is a leader in research and development, and innovation.
• Plastics materials and applications are constantly developed and improved
• Significant industrial research and development is supported by a University infrastructure of polymer or polymer engineering departments (including Polymer – IRC)
• Polymer Innovation Network (PIN) formerly Faraday Plastics plays a leading role promoting innovation.
4. Social Sustainability
Completing the final pillar of sustainability, plastics are also socially sustainable;
• The UK plastics industry is socially inclusive and offers a wide range of worthwhile careers with considerable room for career development, progression and training. The industry is very attentive to training and this is led by Cogent (the Sector Skills Council) and Polymer Training in Telford.
• Plastics companies are geographically widely distributed across the UK and provide jobs to some 180,000 people.
• The plastics industry has a superb industry health and safety record as demonstrated by BPF accident survey statistics.
• Plastics make a major contribution to safety, the used plastics in cars, for example, reduces weight and allows for the addition of safety features such as airbags. Furthermore, plastic foams such as EPS and EPP provide the necessary shock absorbency to be used in life saving devices such a bicycle helmets.
Plastics are essential in modern day healthcare. Plastics products are used in surgery, healthcare products, pharmaceuticals, drug delivery systems and medical packaging.
• Essential medical applications include:
• Blood bags
• Fluid bags
• Heart and Lung bypass sets
• Blood transfusion sets
• Blood vessels in artificial kidneys
• Surgical gloves
• Catheters
• Endotracheal tubing
تصاویر مرتبط