Plastic is a compound that we are all familiar with. It commonly refers to a vast assortment of synthetic and semi-synthetic substances and is categorized into two types on the basis of raw material used- bioplastic, which is produced using biomass sources like Cellulose and starch; and Polyplastic which is primarily made of crude oil. Plastic is what makes modern life possible and everything from plastic bottles to electronics to airbags in automobiles is made of plastic. Plastic is lightweight, durable, flexible and resistant to water, electricity and chemicals, which is what makes it so popular.
But plastic isn’t the magical solution to our needs. Since the mass-generation and usage of plastics in the 1950’s, discarded plastic wastes threatened to cause damage to the environment as well as human life. It was only two decades later that a resolution to this problem emerged in the form of plastic recycling. The first plastic recycling mill was set up in 1972 in Pennsylvania, and several others followed. The main objective of these mills was to convert plastic waste into something useful. Additionally, the governments of several countries put special efforts into recycling and encouraged the people to use recycled products. As the years rolled on, more and more people understood the benefits of recycling plastic and manufacturers were forced to produce goods made out of plastic that could be recycled. There was a major break-through in the 1990’s with the embracing of PET and HDPE plastic, which are well known today as plastics that can be very easily recycled.
Despite the dangers that plastic poses, it is not possible to cease using plastic altogether since the modern civilization can’t thrive without it. This is what makes recycling the need of the hour. Recycling not only reduces pollution, but also lowers the need to create more plastic. Every year, millions of marine animals die because of ingesting plastic wastes thrown into the oceans. By decreasing the amount of plastic in water bodies, recycling can also save animal lives. Since most plastics are hydrocarbons that are made of petroleum, a process coined ‘pyrolysis’ is used in which plastic are exposed to high temperatures in order to change them back into liquid fuel. Hence, recycling also helps in fuel conservation. From the economic standpoint, plastic recycling is a business. Thus, it leads to generation of jobs, builds more competitive manufacturing industries and also increases the government’s tax revenue. The society on the whole also tends to function more effectively in a clean environment.
How is plastic recycled? It all starts with segregation of plastic wastes on the basis of polymer types. Most industries use a mix of multiple methods to group plastic waste, including manual sorting and automatic mechanical processes which separate plastics by type, colour, density and composition. This step is essential for two reasons: One, since plastic has many varieties, some of which like PVC and LDPE can’t be recycled. Two, if all plastic are recycled together; the results will be less than desirable. The second step involves shredding, washing, and pelletizing of the segregated plastic. After that, it can be melded to make new products. This method of recycling focuses on transforming plastic wastes into secondary raw materials, and is called Mechanical recycling. There is another technique for recycling, called chemical method, in which plastics are broken down into monomers. This alteration in chemical structure is done by mechanical crushing and re-melting. Further processing enables the creation of new products. The chemical method uses advanced technology and is more suitable for the kinds of plastics that can’t be easily recycled. Shampoo bottles, traffic cones, trash bags, flower pots, bubble wrap, synthetic fibers and kitchenware such as cutting boards, food trays and containers, are common examples of everyday items that are made from recycled plastic.
In a country like India, plastic pollution is unchecked, and plastic wastes clog the streets and rivers. In a situation like this, India’s informal plastic recycling is flourishing, consisting predominantly of rag-pickers, small start-ups and non-governmental organizations. An example of this statement would be the construction of roads using plastic that was recycled through the plastic shredding machines in the Vengurla Municipality, near Goa. Today, there are around 7500 plastic recyclers that mostly use the mechanical method. The extensive promotion of recycling can be traced back to the 1990’s, and the number of recyclers continues to rise, but they are still vastly inadequate. The lack of sufficient government investment, public participation and awareness doubled with low technology and finance are to blame for this inefficiency. The government of India has banned the use of plastic carry bags and containers and vows to ban the use of single-use plastics by 2022, as well, but a separate aim towards improving plastic recycling has not been set.
Plastic recycling is not impervious to drawbacks. Manufacturing materials from recycled plastic is energy consuming in its own right and many argue that it is not as beneficial to the environment as ‘reducing’ or ‘reusing’. Recycling can also add to pollution, especially in less developed nations where segregation is done manually and there is a high probability that toxins could seep into the environment. The heat generated during recycling generates carbon emissions, which could incense global warming. There is also no guarantee of the quality of the recycled materials, as each cycle of recycling further reduces the length of polymer chains, which results not only in loss of quality but also in the eventual need to dispose the plastic. It’s also time consuming and expensive and many types of plastic can’t be recycled at all.
Technological advancements are the key to perfecting recycling. For example, emerging techniques like electrostatic separation and froth flotation can help to save time and effort. The emphasis on chemical recycling methods with lower energy needs and a compatabilizer which eliminates the need for sorting, and expanding recycling research to plastics other than PET is the way forward. But we are not yet in a position to adopt these methods completely, and in the meanwhile, adopting alternate techniques like reducing the use of plastic and reusing plastic as much as possible is the best alternative.