Types of Plastic

The use of plastic or polymers has expanded dramatically all over the world in the last 50 years. As of 2019, the market size of global plastic was $450 billion and it shall expand at a CAGR of 4.2% from 2020 to 2027. Due to the depletion of natural gas and petroleum, the common sources of polymers, manufacturers are using other renewable resources like food waste, sawdust, cornstarch, and vegetable oils and fats to make polymers.

Plastic is a polymer that may be shaped and moulded into a product under pressure and moderate temperature. Interestingly, plastics can be categorized into 7 different types. While some are less hazardous and recyclable, others need to go through a more complex and sophisticated recycling process to reduce its impact on the environment. The impact plastics have on the environment can be analyzed from the information on different types of plastic products.

7 Different Types of Plastic

Plastics may be divided into two main categories- thermoplastics and thermosetting plastics. While thermoplastic may be softened, recycled, reshaped and moulded easily, thermosetting plastic is not as easy to mould or recycle. Thermoplastics may be further categorised into semi-crystalline and amorphous.

There is no specific molecular structure to the thermoplastic material. It is usually a clear, solid and stiff material with low shrinkage. On the other hand, semi-crystalline polymer has a structure but is also inclusive of amorphous material.

Most thermoplastics have the word ‘poly’ as a prefix which is followed by the name of a source-based monomer. Therefore, we get names like polyethene and polystyrene for homopolymers. Some polymers may also have more than one word in the name (for example, polyvinyl chloride).

For a better understanding of the 7 different types of plastic, let us study the below pointers.

• Polyethylene Terephthalate (PET or PETE or Polyester)

Polyethylene Terephthalate or PET is commonly used for making plastic bottles, plastic bags and other materials that are commonly used for packaging purposes. PET prevents the food or drinks from getting oxidized, thus spoiling it. It also seals the carbon dioxide in aerated drinks from getting out.

Since PET is a wrinkle-free fibre, it can be easily recycled. However, the plastic contains antimony trioxide which is known for causing cancer to living tissues. More the temperature around, the higher is the release of hazardous material from the plastic. Therefore, it is advised to either recycle the plastic or crush it after use.

• Polystyrene (PS)

Polystyrene is a highly disposable plastic that is commonly used in food containers, disposable cups and egg cartons. Exposure of this plastic to hot and oily food can cause severe damage to the brain and immune system. It also impacts the nervous system, lungs, liver and genes.

• High-Density Polyethylene (HDPE)

The High-Density Polyethylene is stronger and thicker as compared to other plastic types due to its composition of a long virtually unbranched polymer chain. HDPE is more stable than PET and it is also a safer option for storing food and drinks. This type of plastic is commonly used in a grocery bag, milk and juice containers, shampoo bottle etc. However, studies show that HDPE can disrupt the human hormonal system when exposed to ultraviolet light.

• Low-Density Polyethylene (LDPE)

Polyethylenes have the simplest plastic polymer chemical structure among the family of plastics which makes them cheap to manufacture and process. The chain branching of polymers for HDPE is long, less dense and less crystalline. This type of plastic is used to manufacture a variety of plastic bags and wraps. LDPE is commonly used to manufacture squeezable bottles and storage bottles. Although this type of plastic is difficult to recycle, it is safe for the storage of food and drinks.

• Polypropylene (PP)

Polypropylene is stiffer and has a higher heat resistance and therefore, it is used for manufacturing hot food containers, car parts and thermal vests. But PP is not very recyclable and the use of this type of plastic comes with health hazards like asthma and hormone disruption.

• Polyvinyl Chloride (PVC)

PVC is the second most commonly used type of plastic. It is used to manufacture toys, blister wraps, blood bags, loose-leaf binders, medical tubing and more. The environmental hazards of using PVC come in abundance. PVC also comes with serious health risks such as cancer, allergic symptoms in children and disruption in the human hormonal system. It is also not as easy to recycle PVC and therefore, the use of PVC must be avoided whenever possible.

• Other

This category of plastic includes the types of plastic which do not fit in the six aforementioned categories. The most common plastic in this category is Polycarbonate (PC). Polycarbonate is highly toxic and is linked to numerous health problems. It also has a low recycle rate.

A little knowledge about the type of plastic helps a great deal with ineffective waste management. Use plastic responsibly and recycle what you can to contribute your mite to making the environment greener.