Many products are made of plastic, e.g. toys, electrical appliances, clothes. These products have different properties depending on their purpose. For example, it is important for a plastic bottle to be break-resistant, a rain jacket must be waterproof, and a laptop case must be durable.
What are the different types of plastic?
Plastics can be divided into three main groups, named after their different properties:
Thermoplastics can be remelted and reshaped many times, e.g. PET bottles.
Thermosets are dimensionally stable even when exposed to heat and are
intended to be stable and last a long time, e.g. firefighters' helmets.
Elastomers are elastic, e.g. rubber bands.
Known modern plastics:
PET (polyester terephthalate)
Used for the production of plastic bottles, films and textile fibers
Among other things, crease-resistant, tear-resistant and low water absorption
Used to produce flexible packaging
Harder and more heat resistant than polyethylene
The most commonly used (standard) plastic material
Good chemical resistance, electrical insulation ability
PVC (polyvynil chloride)
Used to make window profiles, pipes and sound panels
Contains plasticizers and can lead to elastic behavior of the material
Also known as Styrofoam
Resistant to water, but will rot when exposed to light
Can have variable density
Can be used to form molding compounds for a plastic manufacturing process
Suitable for packaging of short-lived goods
Can be deformed when heat is applied
PES (polyester fibers)
Used for the production of synthetic fibers, resins, varnishes
Can be made into a high performance plastic
How are plastics made?
Plastics don't just occur in nature like wood from a tree. They are assembled in factories from various ingredients. Small molecules (monomers) are turned into larger molecules (polymers) with the desired properties of the particular plastic. Each type of plastic has its own recipe that specifies which starting materials are mixed together at what temperature and how much pressure. In most cases, petroleum is the main ingredient, or substances derived from petroleum.
There are also bioplastics that are made from renewable raw materials - for this purpose, sugar, for example, is broken down into its individual parts and reassembled.
Plastic can be recycled quite well, which means that new plastics can be made from plastic waste. However, the proportion of recycled plastic in the production of new plastics is only about % so far.
Advantages of plastics
Plastics are very versatile. Depending on its intended use, plastic can now be made to have many desired properties:
It can be hard, break-resistant and durable.
Other types of plastic, on the other hand, are soft, malleable and elastic.
It can be heat resistant, waterproof and resistant to chemicals.
Compared to other raw materials, it is very light.
An important argument is often the price: plastic can often be produced very
cheaply. Compared to other materials, it sometimes requires less energy to
For some areas plastic is the best available material. If products should really only be usable once (e.g. for medical products), plastic is often cheaper for the wallet and for the environment.
In other places, plastic products with certain properties help protect the environment: Reusable PET bottles, for example, are lighter than glass bottles and therefore use less energy to transport.
Plastic can also be the better option for permanent use: because it takes less energy to make pipes from plastic than from metal, for example, the plastic option may be better for the environment.
Disadvantages of plastics
The disadvantages of plastic lie mainly in its production and disposal.
Petroleum as a raw material is not regenerable, i.e. it is not available in unlimited quantities. As long as plastic cannot be completely recycled, raw materials are lost forever. Bioplastics also require resources - land is needed, energy is used for cultivation, and some methods of cultivation harm the environment.
When plastic enters the environment after consumption, animals and soils suffer. Animals might eat plastic which then clogs their stomach or they can get tangled up in plastic nets etc. When plastic waste decomposes or is incinerated, toxins are released into the air and soil. Furthermore, small plastic particles (microplastics) enter the food chain. Read more about this in the articles Plastic- from production to disposal a problem for humans and nature and Plastic in our oceans.
This article was translated from German.