PLASTIC–FRON WASTE TO WEALTH
A fast developing country like India generates various kinds of urban and industrial waste. The range of waste streams includes – municipal waste, construction and demolition debris, plastic packaging waste, e-waste, industrial hazardous and non-hazardous waste and biomedical waste.Over 75% of the waste we generate is recyclable but we, in India, recycle just 30%. It is time for the nation to wake up and know start taking waste management seriously because if this issue is ignored any further then by 2030 we will need a landfill as big as Bengaluru to dump all the waste. According to the Central Pollution Control Board, less than 15% of the municipal solid waste generated is processed or treated. There are various issues plaguing efficient waste management in India, ranging from lack of proper guidelines, planning on the part of authorities, poor waste collection, and treatment system to poor awareness among citizens about waste segregation.
According to government data, Delhi is among the top ten largest plastic waste producing cities in the country. To address the growing waste concerns of the city, Pom Pom started converting recyclables into raw form, which can be used to create new different products.One way to tackle this is to incentivise collection of single use, low value plastics by waste collection to improve the collection rates and ensure that if these plastics cannot be recycled they are either processed by waste to energy including pyrolysis or by co-processing them in cement kilns as alternate fuel. Plastic recycling refers to the process of recovering waste or scrap plastic and reprocessing the materials into functional and useful products. This activity is known as the plastic recycling process. The goal of recycling plastic is to reduce high rates of plastic pollution while putting less pressure on virgin materials to produce brand new plastic products. This approach helps to conserve resources and diverts plastics from landfills or unintended destinations such as oceans.Plastics are durable, lightweight and inexpensive materials. They can readily be molded into various products which find uses in a plethora of applications. Every year, more than 420 million tons of plastics are manufactured across the globe.1 Consequently, the reuse, recovery and the recycling of plastics are extremely important.
What Plastics Are Recyclable?
There are six common types of plastics. Following are some typical products you will find for each of plastic:
PS (Polystyrene) – Example: foam hot drink cups, plastic cutlery, containers, and yogurt.
PP (Polypropylene) – Example: lunch boxes, take-out food containers, ice cream containers.
LDPE (Low-density polyethylene) – Example: garbage bins and bags.
PVC (Plasticised Polyvinyl chloride or polyvinyl chloride)—Example: cordial, juice or squeeze bottles.
HDPE (High-density polyethylene) – Example: shampoo containers or milk bottles.PET (Polyethylene terephthalate) – Example: fruit juice and soft drink bottles.
Currently, only PET, HDPE, and PVC plastic products are recycled under curbside recycling programs. PS, PP, and LDPE typically are not recycled because these plastic materials are more difficult and expensive to processLids and bottle tops cannot be recycled as well. “To recycle or Not to Recycle” is a big question when it comes to plastic recycling. Some plastic types are not recycled because they are not economically feasible to do so.
*How is Plastic Recycled?*
There are different types of plastics. And this makes it impossible to recycle all plastics in the same way. However, there are two methods of recycling plastic.
Traditional recycling is the most well-known form of recycling.It involves sorting items by plastic type at a facility and then cleaning, grinding and processing the materials so they can be used in new products.In most cases, a multi-step process is used to produce the materials that make new plastic products. That process usually includes grinding, washing, separating, drying, regranulating and compounding.Typically, traditional recycling involves only thermoplastic materials. These are materials that can be remelted and reprocessed into new products using injection molding or extrusion. Through traditional recycling, recycled plastic can directly replace new plastic materials (also known as virgin materials) in the production process
Advanced recycling is a process through which the effect of chemicals breaks down plastic material. This method consists of three other techniques. These techniques include pyrolysis, chemical recycling, and gasification.Pyrolysis is a technique that involves recycling plastic waste into crude oil. Chemical recycling entails reducing a polymer into a monomer that can create new products. For example, manufacturers apply chemical recycling to make nylons.On the other hand, gasification converts plastic to gas. Producers use the gas gotten from this process to create energy.Both traditional and advanced recycling have their benefits. However, applying any of the two methods depends on the facilities available. The end product a recycler intends to produce also determines the recycling method.Nevertheless, all methods involve similar steps during recycling.
*Plastic recycling process*
Plastic recycling is broken up into a few distinct steps. Generally these steps remain the same for most types of recycling facilities, but certain steps can be combined or omitted in some situations.
STEP 1: COLLECTION
The first step in the recycling process is always collecting the plastic material that is to be recycled.This step is completely reliant upon businesses, restaurants, and the public to dispose of their plastic waste in the correct place. If plastic waste is disposed of in normal trash bins, it will not be recycled, so it is extremely important to separate common waste and plastic waste.Additionally, it is ideal for governments to have a recycling collection system that goes to people’s houses or businesses to collect the plastic waste. If this is not possible, local collection points for plastic should be easy for the public to access. Making it easy and convenient for people to correctly dispose of plastic waste is paramount in promoting recycling.
STEP 2: SORTING
After plastics are collected and transported to a recycling facility, the next step is sorting.Machines sort plastics into different areas based upon a multitude of properties that are often dependent upon the recycling facility or what final product is being produced.Plastics are usually sorted in a few common ways, such as the type of plastic (material it is made with), color of the plastic, or even how it was made. This is important because different types of plastics must be processed in different ways and some recycling facilities are only capable of recycling one type of plastic. If the wrong type of plastic is processed at the incorrect facility it can reduce the efficiency of the whole process and require the entire batch to be sent back again for resorting.
STEP 3: WASHING
Just like with clothes, fruits/vegetables, and many other things, plastics must be washed before they are further processed. The goal of this step is to remove impurities and everything that is not made from plastic.Most containers and packages have labels, adhesive, or even food residue that must be removed. This non-plastic waste cannot be recycled and can cause the final product to have poor structural integrity.
STEP 4: RESIZING
Resizing consists of shredding or granulating the plastic waste into small particles. This increases the surface area of the plastic, making it easier to process, reshape, and transport if needed.Additionally, it gives recycling facilities one last opportunity to remove any non-plastic waste that has made it through the first 3 steps of processing. This is often done with metal detectors or magnets that will help remove any leftover metal in the mixture
STEP 5: IDENTIFICATION AND SEPARATION OF PLASTICS
The identification and separation of plastics is when the now small plastic particles are tested to determine their quality and class.The first quality tested is density. This is done by floating the particles in a large tank of water. Particles less dense than water will float and more dense particles will sink.Next their air classification is determined. Air classification is an official term for how thick or thin a particle is. This is done by dropping the particles into a small wind tunnel. The smaller pieces will fly higher up the tunnel and bigger ones will remain lower.Two other features plastics are commonly tested for are their melting point and color. These are determined by collecting and analyzing samples from each batch of plastic particles.
STEP 6: COMPOUNDING
The final step in the recycling process is often considered the most exciting because it is when the plastic particles are made into recycled materials usable for future production. Compounding is when the small particles are smashed and melted together into plastic pellets. The pellets can then be used in the production of other plastic products. Throughout this process the plastic may be moved to different plants that specialize in different steps of the process. It can be energy intensive and the better educated we are about the process the more we can reduce the time and energy it requires.