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The term "plastic" is derived from the Greek word "plastikos", meaning fit for molding. This refers to the material’s malleability, or plasticity during manufacture, which allows it to be cast, pressed, or extruded into a variety of shapes - such as films, fibers, plates, tubes, bottles, boxes, and much more.
Can you imagine a world without plastics??..... They have revolutionized almost every sector on the planet. Try looking around, you will find at least half a dozen plastic items around you.
It's really difficult to imagine a life without plastics. In this article, we will try to know about these groundbreaking materials and their technology. Let us know how mankind found them. But before that, we will see what are plastics?
What are plastics? Why are they preferred?
Plasticity, as defined is a property of a material under which it can be easily shaped or molded. Every element on earth exhibits plasticity under a range of physical parameters.
When elements (mostly metals) undergo plastic deformation, its irreversible, beyond their ultimate yield strength or elastic limit. There are mainly two types of plastic viz. Thermoplastics and Thermosetting plastics.
Thermoplastics
– They can be heated to melt and can be cooled to harden again and again.
Thermosetting
– These, when heated, undergo a chemical change to form a network, these cannot
be reheated to reshape.
Now,
what separates plastics from metals? since both exhibit plasticity to a
reasonable extent. Here are few factors which provide plastics with an upper
edge over metals -
1.
Weight
The
weight of an object is an important factor to be considered when it comes to
the efficiency of the products. Plastic parts often weigh significantly less
than the same parts if were made from metal. Below is a table showing comparative
figures.
| Materials | Density* | Materials | Density* |
|---|---|---|---|
| Plastics | Metals | ||
| Polypropelene(PP) | 980 | Aluminium | 2700 |
| Polycarbonate | 1400 | Iron | 7874 |
| Cellulose Acetate | 1290 | Copper | 8960 |
This
gives an upper hand to plastics where strength and wear resistance is not a
concern. This is the reason that almost 11% of a car's weight these days is plastic.
This has significantly increased its efficiency.
2.
Strength to weight ratio
For
decades the strength of plastics was a concern for many product designers as
they are very weak when it comes to thermal and wear resistance, thanks to
their low melting points. However, with advances in plastic composites, and the
addition of carbon fibers, plastic’s S to W ratio has increased drastically. In
some cases they even outperform metals.
3.
Production time
When
it comes to industries, production time is a very important factor for the
the efficiency of the business. The plastic manufacturing processes, such as
injection molding and thermoforming offer fast mass production over metal
fabrication processes such as milling, cutting, etc.
4.
Design compatibility & cost
While
metal parts require various operations for complex designs such as tapping,
threading, grinding, etc. Plastics can be manufactured in one go with
thermoforming and injection molding. This drastically reduces labor and tooling
costs and the overall cost of the product.
5. Also, plastics do not readily oxidize or rather react with the environment, which makes it best for use in oxygen and moisture-rich environments. They being a good insulator also separates them from metals.
You can find more about the comparison here
The major disadvantages that plastics offers are low wear resistance and structural strength. Thus they cant be used as building blocks for heavy operations.
The origin of plastics
It has been found that naturally occurring plastics have been used since the 1200s as horns and tortoise shells by, The Horners Company, London. Plastics were synthetically produced since the 19th century.
The material which is related to the destruction of wildlife whenever we hear of it was invented to save wildlife. Wow….What an irony!!! Combs, Piano keys, billiards balls, etc were made of ivory. Panic had started spreading regarding the extinction of elephants.
In 1867 a billiards manufacturing company offered 10,000$ for anyone who would come up with a substitute for this. A few years later, John Wesely Hyatt came up with a material which he called celluloid, which was made from a polymer found in plants.
And then… the plastics revolution began. They started to be manufactured from petroleum and gasses but still were unavailable for the general public.
But things changed after World War 2, where plastics were used in helmets, aircraft, guns, etc plastic companies were in search of a new market for their products. The plastics entered the market for the general public, with cling wraps, containers, toys, etc and people discovered the potential of plastics.
Bakelite was the first synthetically manufactured plastic in the
early 20th century, and the rest is history.
You
can find the timeline here
Current scenario
Plastics
have been extensively used in a wide variety of sectors (almost all), from
pharmaceuticals, construction to automobiles, electronics, etc. They have
become an integral part of any industry. It is really difficult to imagine life
without plastic. Let us have a look at the applications sector by sector.
1.
Construction – Piping, seals, gaskets, electric linings, etc
2.
Electronics – Mobile, T.V sets, Laptops, Lighting, etc
3.
Packaging – Cling wraps, food containers, bubble wraps, bottles, etc
4.
Cosmetic and grooming – Combs, brushes, clothing, etc
5.
Transport - Automobiles, Aeroplanes, Ships, etc
6. Medical – Syringes, Tablet packaging, Infrastructure, masks, PPE kits, etc
So we can say, the plastic industry plays a major part in the economy and posses a promising future in a few decades.
Plastics
are mainly manufactured on large scale using two techniques viz. Thermoforming
and Injection molding. It is also manufactured using other techniques like 3D
printing but to a small scale where high accuracy is required.
Plastic
posses a great threat towards the environment, this is since it isn’t readily
biodegradable and has always been a concern for many environmentalists.
What will be the fate of Plastics?
To
evaluate this we must take into consideration some factors like reliability,
environmental impact, ease and cost of production, ease of use, availability,
etc. First, let us consider a hypothetical situation where we were to ban all
the plastic products on earth one day and evaluate the consequences.
Now, let's start our day without plastics. You get up from bed, and rush to brush your teeth, without a brush!!...yes you can chew neem twigs, Then you rush to toilet…wait you cant wash...sanitary ware was plastic too.
You think of boiling eggs for breakfast, the egg tray was also plastic…you start sweating in panic and try to switch on your fan…the electric fixture was also plastic…Duh!! There was more plastic than humans around me.
This was just a trailer, to conclude…life without plastics is very very difficult if not impossible. So to completely eradicate plastic from our life is not an option at all, and I don’t think there is a need to take such a step. There are many sectors where the use of plastic is inevitable like transport, construction, electronics, etc. Thus plastics are an integral part of our day to day life.
With
advanced manufacturing techniques like injection molding and thermoforming, it
becomes easier and cheaper to manufacture even the most complex of products. So
its also beneficial from a business point of view.
Let's take a look at the environmental impacts that plastics have. India consumes about 13 million tonnes of plastic and recycles only about 4 million tonnes. Hundreds of marine species have been reported of ingesting plastic. Studies suggest that even human waste contains plastics.
This synthetic has penetrated deep in our environment and is causing a significant imbalance. The lack of infrastructure for plastic collection and recycling is the major cause of this problem.
If this scenario continues, it is estimated by 2050 there will be more plastic than fishes in the ocean, also there are very few cheap alternatives for plastics. It is almost impossible to replace plastic in some sectors like automobiles, construction, electronics, etc.
The government all around the
world are emphasizing on the plastic ban for bags, straws, containers, etc and
giving an alternative paper-based packaging.
Hmmm…so
it seems the major drawback of plastics are the threats to the environment. We
can't stop using plastic, we cant continue using it, What exactly should we do
then??
We have to accept the fact that it is impossible to stop using plastics at least in a few sectors, as long as there is no environment friendly and cheap substitute available. For sectors such as packaging, where bio-friendly substitutes are available, we should emphasize on using them.
The government
should focus on the recycling of plastics more and build a proper supply
chain for reusing plastic with minimal dumping. By taking these measures we can
use plastics more efficiently, at least till there is no better substitute
available.
You
can find more about plastic pollution here
Conclusion
It
has taken great efforts to invent and innovate plastic as it is today. The use
of plastic is very wide and has become an integral part of our daily routine.
It is impossible to imagine a life without them.
While plastics possessing a major threat to the environment the use of them is inevitable.
With advanced manufacturing techniques, the production of plastic
had become very easy. As the population is growing, the use of plastics will also
grow. We will see a great boom in this industry in the coming decades with
advancements in manufacturing techniques and composite materials.
