Plastic: How It's Made and Why It's Bad
It turns out that the process for making plastic might be even more pollutive than the plastic products themselves.
If you’re a longtime reader of this website, then you should know by now that plastic is bad. Plastic is a non-biodegradable, chemically dense, petroleum-based material that’s used in everything from shampoo bottles to bubble gum. Versatile though it might be, however, the process for making plastic is as pollutive, if not more so than the resultant products themselves.
If you aren’t familiar with plastic’s many downsides, perhaps getting a look at how plastic is made will enlighten you.
How is plastic made?
To make plastic, scientists have to take base materials, such as crude oil, and transform them via heat, additives, manipulation, and time into a workable polymer. The process, as with most chemistry, usually begins with the base materials.
What materials are plastics made from?
The majority of plastic products are made using a petroleum base. Though the main component of most of these plastics is crude oil, other materials, such as salt, cellulose, natural gas, and coal are also sometimes used.
What is the plastic-making process?
According to This Is Plastics, those base ingredients are then refined via the plastic-making process into things like ethane and propane. The resultant ethane and propane are then heated in a process known as cracking, until they transform into the monomers ethylene and propylene. As monomers, ethylene and propylene can then be transformed into subsequent polymers via a catalyst.
Once that catalyst is added, the plastic polymer exists in a powdered form known colloquially as fluff. The fluff is fed through a heated extruder, where it melts down and forms a long, workable pipe. Once the pipe cools completely, the plastic is cut into smaller pellets once more. At this point, the heating, cooling, and manipulation has made the plastic workable enough that it can be melted and molded into any number of other products.
According to Plastics Europe, however, not all plastic polymers behave this way. There are two main kinds of plastics that come out of the plastic-making process: thermoplastics, which can be melted, molded, and cooled until they harden, and thermosets, which are not meltable once they have been cooled.
Thermoset plastics are generally stored in their liquid form and packaged in a way that stops air from hitting them. Examples of these thermosets would be epoxy, polyurethane, silicone, and phenolic, according to RomeoRim.
How does plastic manufacturing affect the environment?
As fascinating as the plastic-making process sounds, the bottom line is that it’s not very good for the environment. According to Ecology Center, the process to transform ethylene and propylene into polymers releases toxic emissions in the air. This is caused by a waste-minimization method that utilizes aqueous caustic solutions.
The resultant gases include dangerous chemical compounds like benzene, ethylene oxide, ethylbenzene, and nickel, which can create clouds of toxic gas both in and around plastic factories. Ecology Center reports that such methods of waste mitigation have resulted in accidental chemical spills, explosions, fires, and fatalities. The solid waste created by the process is normally incinerated, but that just puts the chemicals a bit higher up into the atmosphere.
Despite what many folks may think, not all plastics are recyclable. The bulk of plastic recycling is downcycling, which means that plastic degrades with each subsequent turn through the recycling process. Thermoplastics might be able to be melted, molded, and hardened again, but even they won’t last forever.
Instead of biodegrading, most of them just break down into microplastics, which persist in the environment and cause health problems for just about everyone and everything along the food chain.
The sad truth is that until we discover an eco-friendly material as efficient, durable, and cheap as plastic, we might be stuck with it. Either way, thanks to plastic’s persistence, we’ll be stuck with it in some form.