Resource conservation is the planned management of natural resources to optimise their utility, efficient usage in their original application, reuse, and recycling. The aim is to minimise the energy consumed and wastes generated in all stages, from production through the life of the product right up to final disposal.

 

Properties of Plastics

 

Plastics are derived from natural resources - petroleum oil and natural gas. Plastic products have a fascinating, bewildering and even bizarre range of properties. They can be rigid, as well as flexible, they can provide retention (i.e. act as a barrier) as well as selective tailor-made permeation, they are excellent insulators, but can also be made conductive. They can have memory and can be even optically active; they can be 'Instant' structural adhesives. They have high impact strength; they can have high abrasion and scratch resistance. The ease with which plastics can be processed into a variety of articles of everyday use is truly remarkable and has no parallel. Plastics are the hallmark of conservation of energy compared to steel and glass and have an additional advantage of recycling.

 

Saving of our Forests

 

Natural Resources The wood used for furniture like tables & chairs, doors & windows, packing of tea, mangoes, grapes, apples etc, wooden crates for aerated water bottles, are now being replaced by plastics. An estimate indicates that if only 2% of the wooden boxes are changed over to plastic we would save 1,200 ha of forests involving 1,10,000 trees.Wooden plate & frame-filters used in chemical & allied industries can be completely replaced by plastic. 

Yearly consumption of Plastic chairs and Plastic Crates in India 2000 AD was about 50 million and 15 million, respectively. At this rate saving over a period of 10 years would be close to 20 million trees.

Cork used in a variety of applications like caps of aerated water bottles can be replaced by plastic. The nursery for forestry also benefits from plastic films.

Cotton and jute, in most applications, can be replaced in a very effective and profitable way by woven sacks made of high-density polyethylene or polypropylene. A lot of wastage associated with the use of packaging jute bags for cement, fertilizer, pesticides, etc can be avoided by using waterproof plastic sacks.

 

Plastics in Agriculture

 

Plastics are used in a host of applications in the field of agriculture e.g. plastic pipes in sprinkler irrigation systems, plastic films in greenhouses, plastic nets in horticulture, heavy duty flexible membrane lines for canal lining which prevents water seepage- (It has been reported that 0.75 mm PVC sheet provides a million times more permeation resistance than 1m of clay as canal, dam and lake liner). Super absorbent polymers in our arid, and semi-arid zones, all help substantially to conserve water - a precious natural resource, to a great extent.

 

Plastics for Fishing Industries

 

Fishing nets made of plastics have a long life. Even ropes are made entirely of polypropylene or polyamide, and these have a long life compared to other conventional ropes. FRP boats have made a definite impact on the fishing industry.

 

 

Plastics in Desalination of Sea & Brackish water

 

Polymeric membranes have made a major impact in recent years in desalination of sea and brackish water. We now have large-scale plants providing drinking water to the public. Here the net consumption of energy, compared to multi-stage evaporator based system is very lower, and hence saving of energy is substantial. The availability of potable water in a number of arid and semi-arid areas in Rajasthan, Gujarat, Tamil Nadu, Andhra Pradesh, etc. is a serious problem of society, and polymers' contribution in tackling the issue is very great.

 

 

Plastics in Cryogenic Operations

 

Many cryogenic operations, for e.g. pure or enriched nitrogen and oxygen, can now be based on polymeric membrane separations or hybrid systems resulting in enormous power savings. Enriched oxygen can be supplied for industrial purposes like boilers, kilns, furnaces etc. resulting in saving of substantial energy. Even in hospitals, enriched oxygen is being supplied through membrane based modules.

 

Saving of Energy

 

Energy consumed on a functional basis, by a unit amount of plastic, (polymers like LDPE/HDPE/PP/PS) which have densities which is about one-seventh of that of steel, is very much lower than that required for steel, and aluminum (aluminum requires 13 times its weight in energy to produce 1 lb from ore, steel six times). Plastic does not need frequent painting. This is another saving. In many applications, steel and aluminum can be safely and profitably replaced by plastic at lower cost and in saving Capital Investment, which we are always in short supply.

 

Plastics (HDPE) pipes can be conveniently and advantageously used for transportation of industrial gas, effluent pipelines where liquids may be acidic and corrosive and avoid the aberration that we will have through the leakage of metal pipes.

 

Frictional losses in plastic pipes & fittings as a whole and pipes for sprinkler irrigation systems are less, which adds and to a substantial saving of energy.

 

Replacement of asbestos and corrugated iron sheets with transparent/ translucent FRP sheets that provide daylight as well can result in saving electricity.

 

Another welcome change is the replacement of blades of fans (ceiling, table & pedestal) with the plastic based material, as it will save substantial energy.

 

Polymeric additives make fuels and engines more efficient in internal combustion engines and this helps in conserving scarce petroleum products

 

According to American sources only 4% of United States, energy consumption is actually used to produce plastic raw materials including feedstocks. It takes less energy to convert plastics from a raw material into a finished product as compared to other products. E.G.

 

• Plastic bags require only one-third of the energy required to make similar paper bags.

• Foamed polystyrene containers take only 70% of the energy to make paperboard containers.

• Fifty-three billion kilowatt-hours of electricity are saved annually by improvements in major appliances. Energy efficiency has been made possible by plastic applications.

• Plastics being strong, yet lightweight, require less material to make a certain package compared to other materials, resulting in saving of energy, eg 

 

1. Plastic film wrappers now used for large diaper packs need only 50% by volume than previous packs.

2. In the US 4 million students a day drink their milk or juice in flexible pouches which reduce weight by 80% and volume by 70% as compared to traditional cartons, reducing storage and trash disposal costs.

3. Plastic grocery bags are lighter and create up to 80% less waste by volume than paper sacks, and are recyclable.

 

• Because of durability, flexibility and increased lifespan, plastic bottles etc can be reused several times, eg. Packings for laundry products etc.

• The lightweight nature of plastics helps to reduce transportation costs substantially. A truck that could carry only 5,00,000/- paper grocery bags can transport 2.8 million plastic grocery bags.

• Container breaches, denting and product loss on the package lines during handling are substantially reduced because of plastics' superior resistant to breakage and denting.

• Increased productivity by about 20-30% and reduced capital expenditure to the extent of 50% can be achieved due to highly superior manufacturing efficiency of plastics.

• Corrosion resistance will increase the life of major appliances by about 40% resulting in substantial savings.

• The automotive industries choose plastics for their durability, corrosion resistance, ease of coloring and finishing, resiliency, energy efficiency and lightweight, which reduces handling and transportation costs. Ease of fabrication and outstanding thermal insulation, reducing energy consumption are the prime considerations for major appliances manufactures for using plastic.

• Aesthetic appearance, durability, ease of installation and energy efficiency are the prime factors for the building and construction industries to use plastic.

 

Some of the experiences of the US plastic industries as reported are: Less waste - Plastics often help product manufacturers to do more with less material, which is known as 'resources efficiency' or 'source reduction'. Source reduction is the process by which a package or product is made using fewer resources, creating less pollution and utilising fewer potentially toxic ingredients.

 

Manufacturers benefit by using less stuff, as their cost is less and this helps to keep their consumer prices down. This also results in resource conservation. The following quotations will clarify certain other points:

 

"Plastic Engineers have helped manufacturers make production using less material by lightning and thinning consumer product packaging. Just 2 lbs plastics can deliver 1,000 ounces - roughly 8 gallons - of beverage such as juice, soft drink, milk or water. In its place, we will need 3 lbs of aluminum to bring home the same amount, 8 lbs of steel or 27 lbs of glass".

 

"Plastics help make packaging more efficient, thereby conserving resources. As a result, the consumer can buy larger, economy size products (eg: laundry detergents). It also means that it takes fewer trucks - and therefore less fuel - to get the products to the consumer. For example, It takes seven trucks to carry the same number of paper bags that fit in one truckload of plastic bags".

 

"Reuse provides another significant way to conserve resources. Plastic's durability allows many products and packaging to be reused over and over again. Not surprisingly, in a 1977 Survey, Wirthlin Worldwide found that more than 80% of Americans reuse plastic products and packaging for their homes. Plastics are durable, making it a material of choice for commonly reusable items, such as food storage containers and refillable sports bottles. Reuse of plastics reduces trash disposal costs and extends landfill capacity. For example as much as 40% of certain plastic parts from damaged or discarded cars are repaired and reused, reducing the number of automotive components sent to landfills. Laundry products are also being packed in reusable plastic bottles and small refill packages of concentrated products - helping to reduce packaging waste".

 

"Many US businesses have made the decision to receive their supplies and ship their products in reusable plastic containers (RPSCs) rather than single-use corrugated boxes. Over the past two years, the Ford Motor Company has eliminated more than 150 million pounds of wood and cardboard packaging that would have gone to landfill, by asking its suppliers to use returnable plastic shipping containers and plastic rather than wood pallets. Returnable containers are also making major inroads in the produce and meat packaging industries".

 

Cdn professor develops the plastic that more efficiently converts ...

Halifax Daily News - Halifax, Nova Scotia, Canada

... other researchers combined specially-designed minute particles called quantum dots, three to four nanometres across, with a polymer to make a plastic that can ...

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