What is Plastic Recycling and How to Recycle Plastic

What is Plastic Recycling and How to Recycle Plastic 

There is plastic all around us. From soda bottles, grocery bags, to your ID card, we see and use plastic every day. Many of these plastics come from materials like petrochemicals. The amount of plastic around us can have advantages and disadvantages.

Plastic can cause litter and pollution in the environment.  These effects can put human beings and the environment in danger. Also, if you do not correctly manage plastic, making new ones can be a waste of resources. It is thus reasonable to reuse and reprocess plastic to prevent waste.

Plastic recycling is the method of gathering waste plastic and reconverting them to new and useful plastic products. The world produces and makes use of more than a trillion pounds of plastic material. Plastic recycling ensures that this massive amount of plastic does not go to waste. Instead, you can reprocess the materials to get other products. 

What are Common Recycled Plastics? 

PET :PET (Polyethylene Terephthalate) is a popular thermoplastic. This material is thin and is perfect for producing low-pressure products. Clothing fibers and soft drink bottles are popular products made from PET.

PVC:PVC (Polyvinyl Chloride) is another thermoplastic. It is also one of the commonly used plastic materials around the world. PVC is used to produce wires, pipes, bottles and clings films.

HDPE:HDPE (High Density Poly Ethylene)is also a thermoplastic. It is softer and more flexible compared to PVC. Examples of products that manufacturers use HDPE to produce are gallons and pipes.

LDPE: This material is the opposite of HDPE. LPDE (Low Density Poly Ethylene) is used to make plastic bags. Sometimes, it is not easy to recycle this material. Instead of recycling, you can clean and reuse them for other purposes.

However, the fact is that you cannot recycle all types of plastic. This is because plastic products come from different types of materials.  And it is uneconomical to recycle some of these materials.

Usually, this is either due to the long process or high cost. And sometimes, the ineffectiveness of the existing recycling process. For instance, if you put these materials in recycling equipment, they may cause the equipment to stop or break.

PS:PS is a polymer. Examples of products that come from this plastic include plastic cutlery and yogurt containers.

PP:PP is also a polymer. Manufacturers frequently use it to make plastic boxes, plastic furniture, and plastic jar lids. In most cases, recycling companies will reject it for recycling.

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

This method is the most widespread recycling method. Another word for traditional recycling is mechanical recycling. This method is suitable for recycling thermoplastic materials.

The traditional recycling method involves melting plastics and processing them into new plastic products. After recyclers melt the plastic, they make them into new products through a process called injection molding.

Advanced Recycling

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. Don’t worry; we will tell you these steps in the next section.

Step-by-Step Process of Plastic Recycling

The recycling of plastic is not as hard as manufacturing new plastic products. Nonetheless, plastic recycling is not a walk in the park. It involves rigorous procedures and attention to detail. The processes may take months.

Irrespective of the type of plastic and its usage, it usually undergoes some general steps during recycling. Here are six essential steps to recycle plastic materials.

Step 1: Collection of Waste Plastic

The first step to plastic recycling is gathering waste plastic products. While this process may seem like an easy task, it is not entirely so.

At this stage, employees or volunteers go around collecting waste plastic from homes, offices, and public places. Certain areas have collection sites where people can dispose of their plastics.

Some recyclers put recycling bin around public locations, residential areas, and industrial zones to ease collection. People can dump their plastic waste into these bins. These bins are separate from regular refuse bins. The recycle bins then get collected and transferred to recyclers to continue the process.

Many times, manually gathering plastics or dropping plastic waste into recycling bins may come with rewards. Recyclers retrieve all types of plastic at this stage and send them to a collecting yard.

Step 2: Sorting of Plastics into Categories

After collection, recyclers send the plastic they have gathered to facilities where they separate the plastics according to types. As you must already know, plastics differ in size, color, thickness, and use. In this process, recycling machines sort plastics based on the properties of the material.

Often, color and the resin content in the plastic are the basis by which recyclers sort plastics. Sorting is essential because it allows recyclers to know which material is involved and how it gets recycled.

Step 3: Washing to Remove Impurities

After sorting plastics, recyclers wash the materials to remove impurities. These impurities in plastic include paper labels, dirt, and particles. Washing plastic also removes glue and additional chemicals that plastic materials may contain.

Washing is essential because failure to remove impurities may damage the new product. Moreover, the contaminants contained in plastic products are not plastic materials and may not be recyclable.

Step 4: Shredding and Resizing

This process comes immediately after washing plastics. It is impossible to recycle plastic in its already developed state. There is a need to resize the plastic material to a form that can be recycled. In this fourth process, materials will be put into shredders to reduce the plastic into fragments.

A plastic material cut into tiny pieces is more comfortable to process than when it is in its original form. Shredding also makes it possible to reprocess plastic to other materials aside from plastic products. Resizing also makes it easier to identify elements like metal that recyclers failed to discover during washing.

Step 5: Identification and Separation of Plastics

After resizing has been completed, the next process is to identify and separate plastic materials. In this process, plastic particles undergo testing procedures.

The reason for testing plastics is to identify the class and quality of the plastic. The plastic materials are then separated based on their features for further processing.

There are several features tested in this process. One of these qualities is density. Recyclers place these plastic particles into a container of water to determine the density of plastic. The particles that sink are less dense, while those that float are denser.

Another quality that this process tests for is the air classification of plastic materials. Air classification determines the thickness of plastic. And to assess air classification, recyclers put plastic particles into a wind tunnel. Thicker and bigger plastic will stay at the bottom of the wind tunnel. The thinner ones will float.

This step also identifies other qualities like color and melting point of plastic. Recyclers test samples of plastic materials to determine the melting point and color of each material. After the identification process, they separate the plastic particles and send them for further processing.

Step 6: Compounding

Compounding is the final process in plastic recycling. This step is where recyclers transform plastic particles into materials that manufacturers can reproduce. Compounding involves smashing and melting plastic particles to create pellets. This process is also called extrusion.

Sometimes, recyclers move plastic to different areas where they can be recycled. The recyclers may move the materials to other plants because of the features in step five. A recycling company may not have the capacity to process all the plastic types it identifies.

At the end of this stage, new plastic and non-plastic products originate from the pellets’ processing. This final process also consumes the most time and energy. Recyclers must fully understand the end product they aim to get and the entire process to manage time and energy efficiently.

After all this, new plastic materials then emerge. Or other materials that the recycler intended to create.