Where Plastic Comes From and How It’s Made Into Everyday Products Plastic is everywhere! We use it when checking our phones, driving cars, and grocery shopping. I’m even using plastic while writing this paper. Plastic is made from oil pumped from the ground after drilling more than 6,000 feet under. This oil is brought to the surface by pump jacks, these pump jacks can produce from 5 to 40 liters of oil from each stroke. This oil travels through underground pipelines into an oil refinement factory. The oil is then divided and mixed with other chemicals to create gas/fuel, chemicals, and plastics.
To produce the thermoplastic polymer known as LDPE they use high temperatures and pressure from organic peroxide which produces a low crystalline branched polymer. Low density polyethylene polymers also known as homo polymers due to the singular monomer (ethylene) within the polymer is just one of the three primary plastics used in everyday life. It is made into squirt bottles, plastic wraps, packaging and some plastic bags. LDPE lining is also in most aluminum cans because this type of plastic is malleable, resilient and most times water proof due to the mix of long and short branched chains in the backbone of the polymer. The short chain branches cause a defect when the molecule begins to crystallize which causes smaller lamella to form making it appear translucent. Melting Point: 105-115 °C LDPE Physical Properties
Good chemical resistance
Low water absorption
Easily processed/low cost
High density polyethylene is a linear version of polyethylene and the most common plastic used in the world. It can be made thin, fluffy, strong, or flexible. High density polyethylene is made into things such as furniture, car parts, and bags/bottles. This extremely strong plastic can also be used to contain agrochemicals and hazardous materials. To produce HDPE crude oil is heated in a process called “cracking.” Once ethylene gas is made and heated, benzene is combined with UV light rays this is what helps the ethylene polymerize. Depending on how many monomers are formed the polyethylene will have a low, medium, or high molecular weight.
Molecular Weight: Low- liquid lubricants Medium-waxy High-malleable or solid/hard & strong Melting Point: 120-140 °C HDPE Physical Properties:
Relatively stiff/ can be flexible
There are five main ways to produce different types of HDPE. Depending on what plastic manufacturers are trying to make different processes such as cast molding, injection molding, blow molding, compression molding, rotational molding, and wood plastic molding are applied. These different processes allow us to buy the plastic bottles, toys, and the technology we use in our modern world everyday. Molding Using Casting This is when the plastic is warmed creating a liquid. It is then transferred into different molds. Injection Molding This process creates three dimensional objects. Plastic is heated and injected into a chilled 3D mold. Blow Molding Molten plastic is first injected into a cold mold, a tube is placed inside the top and air is blown into the tube causing the plastic to form around the mold leaving the inside hollow. Compression Molding Molten plastic is poured into a mold a second mold is inserted into the first mold to create the desired shape. Rotational Molding Two mechanical arms hold the mold in place as the liquid plastic is injected, it then rotates the mold until it is dry. Wood Plastic Molding Plastic is first slowly cooked at a low temperature to eliminate all oxygen. Then poured into a mold containing wood shavings, this creates wood plastic.
Materials, Trash, and Recycling Project Reflection
How does the chemical composition and structure of a substance determine its properties with regard to its use, capacity for reuse, and capacity for recycling? The chemical composition and structure of high and low density polyethylene makes it a globally used substance. Polyethylene also known as plastic is recyclable depending on the plastic being made. Many plastic products cannot be reused or remade into other products by reheating. But by up cycling we can make simple things such as trash cans, wallets, bags, even clothing many things can be made by up cycling. We keep producing more and more plastic products every hour of every day causing our carbon emission levels to rise at a rapid rate. There are many alternatives for the plastic bags and packaging we use all the time.
How do the choices we make as consumers (purchasing, use, reuse, recycling, and discarding of materials) impact our local community and environment, and the global community and environment? Again, be specific and avoid generalities like “plastic is bad for the environment and the oceans.” Plastic specifically majorly affects our global carbon emission rates. It is a huge reason why global warming is an extremely big problem worldwide. Although plastic only takes 20 years to decompose in the ocean it takes up to 1,000 years to decompose in a landfill. Since dumping our waste in the ocean is an illegitimate option we need to start as a whole reducing our plastic production, use, and start to recycle. In doing this together we can make a difference and change the amount of carbon being released into our oxygen daily.
What else did you learn through this project? I learned very much about how plastic is produced from oil, what certain types of plastic and the five main plastic molding is used for. I also learned many alternatives to throwing my plastic waste into the trash because many plastic materials are reusable and recyclable. I have begun to notice the amount of plastic I use all the time and I feel guilty because It’s a lot. Since this I have started limiting my plastic usage as much as I can in order to do as much as I can to change this part of our world. Talking to my peers with similar projects helped me fully understand the complete lifecycle of plastic which changed my whole view. Before this unit I didn’t realize how much of an impact little things have on our world.
What grade do you believe you earned on this project? I believe I stated and accurately answered the essential question for this unit. I completely answered it and stated reasons and evidence on how I know, what I have learned, and the questions I have. In my project I stated the chemical composition of the polymer I worked on and how it can be produced, used, reused, and recycled. I cited my sources and created a bibliography to strengthen my credibility, I also explained how I realized my excessive plastic use and started to limit my use to do what I can to help. I put a ton of work into my project, I even started early to ensure I would finish in time. I put my best effort. I showed up ten minutes before the exhibition so I barely had time to change giving me no time to get set up. Since I didn’t know where to set up we set up a bit late but still got going quickly. From doing this self reflection I deserve a B+ on the first essential question, an A for the second essential question, an A for work ethic and end product, and a B for exhibition cohesiveness.