Which are 6 Common Types of Plastic?

Plastics are polymers, and the word polymer comes from the Greek word Poly which means many, and Mer means repeating units. Plastics are made from Organic materials, which are obtained naturally and are also produced by Man. Plastics contain mainly elements like Nitrogen, Oxygen, Carbon Hydrogen, chlorine, and Sulfur are also present in some types of Plastic polymer. It has been over a hundred years since the discovery of plastic, and it has become one of the most used products. Looking around, we can see the amount of plastic surrounding ourselves. Therefore, plastic has become one of the major causes of Plastic Pollution. The effects of plastic pollution are not hidden. It's evident and quite visible to the human eye.

Chemistry of Plastics

Let's take a look at the plastic produced by different industries. The petrochemical industry is one of the major industries producing most plastic. The Crude oil, which undergoes Fractional distillation, separates into various compounds like Petroleum, Diesel, Paraffin and Naphtha. Plastics are produced by Naphtha, which contains Carbon Compounds with a Carbon Chain of C5 to C10 (pentane to Decane). When this Naphtha is cracked by decomposing it at 800°C and broken, we get plastic made from Propylene (C3) and Heptane(C7). Plastic is made from polymerization (polymerization is a process in which small units of Monomers keep binding to each other in a repeating sequence), which is further classified into two classes, Addition and Condensation Polymerization. Plastics like Polyethylene, Polyvinyl Chloride are produced by Addition Polymerization, while Nylon and Polyester are examples of Plastics or polymers produced by Condensation Polymerization. Plastics are classified into 10 different types of Plastics and there are six major type of Plastic you should be aware about.

Which are 6 Common Types of Plastic?

At the bottom of the Plastic Bag, a Number is always mentioned. Many of us might not know the importance of the number. There are Six Different types of plastic which include:
• Polyethylene Terephthalate (PETE)
• High-Density Polyethylene (HDPE)
• PolyVinyl Chloride (PVC)
• Low-Density Polyethylene (LDPE)
• Polypropylene (PP)
• Polystyrene (PS)
• Others.

These Plastics are classified on the different kinds of Monomers used.

What are Different Types of Plastic?

The different types of plastic are mentioned above. These Plastics are classified as Clear, Solid in colour, Flexible, rigid, Cloudy and soft. Plastics are produced through resins which are blended with different additives. These Plastics are said to be one of the biggest contributors to increasing pollution. They harm and affect wildlife and marine diversity. Plastic debris is one of the leading causes of Plastic Pollution and is classified into three main types:

Micro debris: if the plastic molecules range between the sizes 2-5nm, the plastic molecules degrade into smaller sizes, and these smaller sizes are prone to be released without any treatment from the industries.

Macro debris: Plastic molecules with sizes above or up to 20 nm are called Macro debris. Plastic bags given by the grocers are one of the leading causes of Macro Debris. Plastic Bottles are also a type of plastic that has adversely caused major Macro Debris.

Plastic has affected a major portion of our Earth without even us realizing it, the effects of plastic pollution are still evident, and the harmful effects of plastic pollution are:
• Plastic pollution has affected the land and livestock, and plastic concentration is 423 times higher on land than in oceans.
• Plastic can lead to animal poisoning, and they are harmful to domestic as well as marine mammals. Many studies have shown the amount of concentrated plastic Debris in Sea Turtles' bellies.
• Plastic has adverse effects on humans. During the process of plastics, chemicals like Bisphenol A are polybrominated. Diphenyl ether is used. These organic compounds are harmful and can cause major health problems.

Knowing the different kinds of plastic can help to reduce plastic pollution. Many countries have started initiatives and laws that ban plastics, but that just solves half the problem. For example, countries like Australia have started their Plastic Free July since 2011. Plastic-free July is celebrated by prohibiting the maximum use of single-use plastic-based products like straws, bottles and more. Plastic free July was an initiative started by Rebecca Prince Ruiz and now is one of the most influential movements.

1) Polyethylene Terephthalate (PET or PETE)

PET is a single-use plastic used for packaging food and other goods. You can find yourself surrounded by the bottle, the carbonated soda you consume, the Nutella jar, the cooking oil bottles, everything you use and have been packed is made from Polyethylene Terephthalate. FDA and ACC have given a green signal for PET to be used as a material in the food, pharmaceutical and beverage packaging. What about Bisphenol A? While this may be controversial, The American Chemistry Council has said that PET does not contain Bisphenol A and is safe to use. PET is one of the most easily recyclable plastics. PET plastics are labelled with Number 1 inside a Triangular chasing arrow. The current Recycling rate for PET is 31% and is only expected to grow in the future.

2) High-Density Polyethylene (HDPE)

HDPE belongs to the category of Thermoplastic polymers, which are derived from Petroleum. It has a wide variety of uses and is used for Daily activities. For example, food like Milk is packed in containers made from HDPE. HDPE is also used to pack shampoo and other Cosmetic products. HDPE has many benefits and is approved by FDA and NSF. The Containers made from HDPE are easily malleable and remain rigid, as the polymer has a very high Melting point. The HDPE plastics are a type of plastic resistant to mold and ideal for piping. These HDPE plastics are also acid resistant and are used by the chemical industry. The HDPE has a greater tensile strength compared to LDPE, which is because of the strong intermolecular attraction of the polymer. HDPE is a type of plastic that can be reused again, and 10 ways to reduce plastic pollution include reusing the bottles made from HDPE and choosing manufacturers that use recycled bottles. This is one way which will help in reducing Plastic Bottle Pollution.

3) Polyvinyl Chloride (PVC or Vinyl)

PVC plastics or Vinyl Plastics are the third most used types of plastic. PVC is used extensively in the construction industry and in the medical field and insulation work. Plastic is easily available and durable. PVC production is cheap and replaces materials like Ceramics, wood, concrete and more. The first time PVC was made, German Scientist Eugen Bauman unintentionally created it. He kept the Vinyl Chloride Exposed to sunlight, forming a white solid called PVC. After that, German Chemist Friedrich Klatte gave the first method for Polymerization of PVC. PVC is classified into two different kinds of plastic, whether it's rigid or flexible. PVC is a very versatile kind of plastic and also cost-effective.
• It's used as an Insulator because it has a good dielectric constant.
• The PVC plastics are resistant to harsh changes, which does not affect them; hence they are resistant to weathering, corrosion, rotting and shock.
• PVC contains additives like Antimony Trioxide, which help PVC to be fire resistant.

10 ways you can recycle PVC-based materials include chemical and mechanical techniques. Mechanical cycling includes grinding the waste into smaller particles and remodelling them into different plastic Products. This is an effective way which can reduce the cause of plastic pollution. The other technique involves pyrolysis, in which the Material is broken down into smaller chemicals, and used in other manufacturing processes.

4) Low-Density Polyethylene (LDPE)

Low-density Polyethylene is used for its varied properties, which include being lightweight, soft and flexible. In addition, they provide high-Temperature resistance and are often used in prosthetics. The manufacturing industry does the major use of LDPE. It has major advantages, which include:
• It provides high resistance to alcohol and acids.
• Low cost.
• Has good insulating properties.
• Transparent if in the form of Film.

These are widely used to make dispensing bottles, tubes, and plastic bags for electronic components. One of the good reasons why LDPE is used for packaging in Industries is because this plastic type is easily available and has a low cost. Major Pharmaceutical and food packaging industries use the LDPE kind of plastics. LDPE makes pipes and hoses for those pipes because of their low water absorption property. LDPE plastic is recycled and used again as piping and trash bags among the ten ways to recycle plastic. They are also used as plastic bags and Composite Lumber.

5) Polypropylene (PP)

With propene as its monomer, Polypropylene is a types of plastic that is rigid and tough thermoplastic. Polypropylene is available in two forms:

Homopolymers: Propylene is semi-crystalline and is widely used in the textile, healthcare, and automotive industries. Homopolymer PP has a strong resistance and stiffness.

Copolymer: in this polymerisation process, Propylene is mixed with other additives like Ethylene and a copolymer is formed. It has superior toughness and durability.

Polypropylene is widely used in manufacturing slippers and plastic-based furniture. Polypropylene has a higher resistance to corrosive chemicals, making them an ideal choice for packing bleaching and cleaners. Due to their high insulating properties, they are used for packing electrical products. Many daily used goods like ropes, tapes, and clothing are made from a kind of plastic known as Polypropylene.

Recycling Polypropylene: being one of the most common types of plastic being used, it's also one of the leading kinds of plastics that cause plastic pollution. The effects of plastic pollution is visible and is not hidden. The 10 ways to reduce Plastic Pollution for Polypropylene can be done in five simple steps:
• Collecting: collecting plastics is the first step of the recycling process.
• Sorting: it is important to know the different kinds of plastic, as every types of plastic needs to be treated differently. One of the easiest ways could be to check for the Number 5 mentioned on the Plastic Bag indicating Polypropylene.
• Cleaning: cleaning plastic is a very important step, and it helps sterilise the plastics.
• Reprocessing: Processing Polypropylene is done by melting it at high temperatures.
• Manufacturing new products.

6) Polystyrene (PS or Styrofoam)

The next types of plastic is polystyrene, used in the laboratory and food packaging industry. Polystyrene is available in Foam, which has good insulating properties. Styrene is the major monomer which is used to make Polystyrene. Polystyrene has a wide application and is used in many major industries:
• Polystyrene is used in appliances like vacuum cleaners and refrigerators. It is used in the form of Foam and solid form as well. One of the main reasons for Polystyrene being used in appliances is inert and cost-effective.
• The car panels and door knobs are made from Polystyrene. Polystyrene is also used to make doors which absorb energy and for sound dampening.
• In food serving the packaging, Polystyrene is used to keep the food fresh.
• Polystyrene can be easily sterilized; hence, it has a wide application in the medical field, including making test tubes, housing test kits, Petri dishes and more.

Recycling of Polystyrene:

Recycling Polystyrene is not easy, and it's a kind of plastic which is difficult to recycle with simple techniques; hence new techniques have been used which reduce the cause of Plastic Pollution by Polystyrene. However, plastic pollution is common in coffee cups or polystyrene bottles, and the effects of plastic pollution is severe. Therefore, one of the common ways which are used to recycle is using Polystyrene Hungry Bacteria.

Recycling Polystyrene has various benefits, and this recycled Polystyrene can be used to make Polystyrene based wood and furniture.

List of Recycling Codes for Plastic

Effective measures have been taken to reduce the effects of plastic pollution, and one such important measure is the use of plastic codes printed on the plastic. This makes the segregation and separation of plastic very efficient. The Society of Plastic Industry gave the Plastic Recycling codes. These codes indicate the types of plastic it stands for:

Number 1: Number 1 indicates the Polyethylene Terephthalate plastic, also known as PETE. PETE plastic is a types of plastic which is commonly used by the beverage industry. The preferred method of Recycling method is through various programs. Recycled plastic is through various programs. This recycled bag is used as packaging films, tote bags and more.

Number 2: Number 2 indicates HDPE plastic. High-Density Polyethylene is a plastic which is used for shampoo containers and more. Through various recycling programmes, this types of plastic is collected together. The recycled HDPE plastic is used to make oil bottles, drainage pipes, fencing, and more.

Number 3: The number 3 indicates PVC plastic. These types of Plastics are used for construction purposes, and when recycled, PVC plastic materials can be used for fitting pipes and decks, drainage mats, etc.

Number 4: Number 4 indicates the LDPE plastic. Through the Curbside program, LDPE plastic is collected and separated. Virgin plastic makes shopping bags and bags for food like bread bags and frozen food. The recycled LDPE bags are used for making floor tiles and landscaping ties.

Number 5: Number 5 Indicates the materials made from Propylene Plastics. Materials such as ice cream containers, lunch boxes and potato wafer bags are made from Polypropylene. In addition, the recycled Polypropylene is used to make brushes, rakes and compost bins.

Number 6: The number Six Indicates the materials are made from Polystyrene. The recycled Polystyrene is used to make coat hangers and insulating Materials.

Number 7: the number 7 indicates the plastic materials made from other materials. This includes polymers like Nylon and Polyester, for example.

List of SPI Codes?

The Society of Plastic Industry set the SPI codes for Plastics. The main objective of setting these SPI codes for plastics was to make plastic eco-friendly. However, identifying the different kinds of plastic is difficult; hence, many codes have been allotted to these plastic-made materials. These codes help separate the various plastics, making the recycling process much easier. The SPI Codes for Different kinds of Plastics are:

SPI Code 1:PET is a popular single-use plastic package food and other items. Everything you consume and have been wrapped is composed of Polyethylene Terephthalate, including the bottle, the fizzy beverage you drink, the Nutella jar, and the cooking oil bottles.

SPI Code 2: HDPE provides numerous advantages and is accepted by the FDA and NSF. Because the polymers has a very significant melting point, HDPE containers are easily malleable and rigid. In addition, HDPE plastics are mold-resistant plastics that are perfect for pipes. These acid-resistant HDPE polymers are also utilized in the chemical sector.

SPI Code 3: PVC is widely utilised in the building business. It is also broadly applied in the healthcare profession and for insulating applications. Plastic is affordable and long-lasting. PVC manufacture is inexpensive and can be used to substitute materials such as earthenware, wood, marble, and others. Friedrich Klatte, a German chemist, developed the first process for polymerizing PVC. Polyvinyl chloride is divided into two categories depending on whether it is stiff or flexible.

SPI Code 4: Low-density Polyethylene is employed for various reasons, including its inexpensive, soft, and malleable qualities. They are employed in prosthetics because of their excellent temperature resistance. In addition, LDPE polymers are widely used in the healthcare and food packaging sectors. Because of its low water absorption, LDPE is used to produce pipes and nozzles for such pipes.

SPI Code 5: Polypropylene is commonly used to produce shoes and foam furniture. Because polypropylene is more resistant to chemical solvents, it is an excellent choice for packing scrubbing and cleaners. In addition, they are used to pack electrical devices because of their great insulating characteristics. Many everyday items, such as cables, tapes, and clothing, are produced of Polypropylene, a types of plastic.

SPI Code 6: Polystyrene is used in the laboratory and food packaging industry. Polystyrene is available in Foam, which has good insulating properties. Styrene is the major monomer which is used to make Polystyrene. In food serving the packaging, Polystyrene is used to keep the food fresh.

SPI Code 7: the plastic materials are made from other materials. This includes polymers like Nylon and Polyester.