Made to Last a Lifetime, Designed to Discard After Use
Back in the 1950s, manufacturers started to produce plastic on large scale. This production skyrocketed over the years to an extent beyond imagination. The production grew from under 2 million tons per year in the nineteen fifties to a whopping 311 million tons per year in 2014. The real value could be even higher as these figures don’t include fibres made from polyacrylic, polyamide, PET and polypropylene. If the trend doesn’t change, the total plastic production might reach 2,000 million tons by 2050.
The reason plastic has become so popular so quickly is that it is cheap, durable and flexible. We all use plastic in our everyday life; we eat from plastic, drink from plastic and wear plastic, without fully acknowledging this fact. Wherever you look around you, chances are you can find at least one item made from plastic. Packaging is the largest sector in Europe that uses plastic, closely followed by building and construction and by the automotive industry. In addition, there are other industries that use a high amount of plastic, agriculture and the electric and electronic industry being only two of these examples. Consumer and household appliances, sport and safety are also huge plastic hogs.
Nevertheless, the same properties that turned plastic into such a popular material are also some of the major drawbacks of plastic use. When it comes to the environment, plastic is one of the biggest pollutants of all times. This lightweight material can easily travel far from the source. Its low cost makes consumers more prone to discarding it. Its durability makes it last for a very long time in the environment. As plastic products have become available to more and more people, the amount of plastic ending up in the environment has also increased to the extent that it chokes and poisons wildlife. In fact, about 10% of all plastic waste ends up as marine litter. Furthermore, industrial plastic often needs to be handled through the safety of glove ports.
The Manufacturing Process
Plastic is made from polymers. Polymers are macromolecules of organic nature. Their structure consists of repeating carbon-based chains. When monomers join together to become long chains, they turn into polymers. This process is known as polymerisation. Monomers are the bricks that build blocks of polymers. A polymer made from identical monomers is a homopolymer, while a polymer made from different monomers is known as a copolymer. The monomers determine the size, structure and main properties of polymers.
The most commonly used monomers include but aren’t limited to styrene, ethylene, vinyl chloride, and propylene. They are extracted from fossil fuels such as petroleum. Apparently, about 4-6% of the global oil production is used for the production of plastic. Biomass (e.g. plant oils) are used to produce bioplastics. Even though these materials aren’t too widespread for the time being, they are slowly increasing in popularity. Nevertheless, a polymer and therefore its final properties aren’t influenced by the type of raw material it is made from.
The plastic production process involves the use of a wide array of chemicals such as solvents, catalysts, initiators, etc. Catalysts and initiators are used only in tiny amounts. Most catalysts are based on metals such as titanium, zinc and aluminium. Peroxides are probably the most frequently used catalysts.
During the later stages of the manufacturing process, the polymer is mixed with additives to alter and to shape the properties of the end product. Plastic production relies on additives, as they are the ones that improve many of the basic properties of plastics. The numbers are staggering; apparently, the plastic industry uses several thousand additives.