Here is an overview of the cycle of plastic and how it’s made. This project was completed as part of a genius hour project in Ms. Gillis' 5th grade class. Currently Liam is working on a new project about the effects of radiation on the human body.
How Plastic is Made By Liam M
Step one: Crude oil
The first step to the production of plastic starts millions of years ago when microscopic organisms called plankton died and fell to the seafloor.When the plankton fell to the sea floor they were eventually covered by sediment.After a while the sediment was so deep that the temperature rose and the pressure increased transforming the dead plankton into petroleum and natural gas.
Step two: Extract and separate
Now factories extract the petroleum and natural gas from giant oil rigs and place it on oil tankers and ship the crude oil to an oil refinery.The first thing the refineries do is separate the crude oil into sections through a process called distillation. Then they heat the sections turning the crude oil into a gas witch goes into a tall chamber.When the gas cools the different separations (which have different boiling temperatures) condense into different liquids.Each separation is a mixture of hydrocarbon chains which have different strengths and sizes of their molecules.One of these separations,naphtha is an extremely important part in plastics production.
Step three: Cracking The third step to plastics production is a heat separation process called cracking.The cracking process breaks down the naptha into smaller hydrocarbon molecules like ethylene butylene and propylene.
Molecules of hydrocarbons like ethylene and propylene are very important for plastics preduction.In a chemical reaction called polymerisation a big amount of individual molecules are attached to make a polymer chain.
Thermoplastics and thermosetsDifferent plastics have different chain structures which determine many of their physical characteristics. There are two main polymer families: thermoplastics and thermosets.
An example of a way to shape plastics is called is called blow extrusion.In blow extrusion the first thing that happens is plastic pellets are put into the barrel of the extruder.Second,the pellets slowly liquify from mechanical energy which is generated by turning a screw and by heaters arranged around the extruder barrel.Finally,the molten plastic is forced past a tubing mandrel and then pumped into a balloon shape.Next the balloon shaped plastic is moved upward by rollers and squished into a collapsed sheet and finally cut into plastic bags to be shipped to whatever company desires them.Of course there are many types of plastic shaping methods and the don't have to make plastic bags this is just an example.
Plankton:Microscopic organisms that live in the sea.
Sediment:A surface of dirt and other small things.
petroleum:A thick and flammable substance that can be refined into oil.
Hydrocarbon:An organic compound completely made of carbon and hydrogen.
Naphtha:A flammable liquid hydrogen mixture produced from natural gas condensates.
Polymerisation:A process of reacting certain molecules to form polymer chains.