Thermosets can be molded as well, though the molds are often pressurized to encourage the polymers to link more closely, which makes the end product more durable. They are also sometimes treated with a chemical before molding to make the polymers combine thoroughly. The first process is usually used to make things that need to be strong, but are made for consumer use, like phones and sports equipment, while the second is used to make stronger things like machine or vehicle parts. This type of plastic can also be coated onto other materials, like paper or fabric, and then heated and pressed together to make fuses, gaskets, and electronic circuit boards in a process called laminating.

Thermoplastics are usually processed by various forms of molding or extrusion . Molding is done by heating up resin and injecting it into a mold or blowing air into a softened tube of resin that's inserted into a mold to make it take a shape. These processes are used to make things like toys, containers, and soda bottles. Extrusion is done by pushing the resin through a mold to make it form a certain shape, and is used to make things like straws, fibers for weaving, and pipes. Thermoplastics can also be calendered, in which they're melted and then pressed between big rollers to make long sheets of plastic, like those used to make flooring.

The polymers can then be processed into either thermoplastics or thermosets. Thermoplastics melt when they reach a certain temperature, but are hard when they cool, while thermosets get harder as they get warmer, but can only be heated up and allowed to set once. If they're heated again, they burn. The difference between them usually comes down to the monomers used to make the resin and the structure that the polymers form while being processed: while thermoplastics form into chains of alternating hard and malleable sections, thermosets form hard, interlocked bonds.

During either process, different types of monomers are usually mixed together to form resin with different characteristics. They may also be mixed with other additives, like flame retardants or plasticizers, which make the end product less brittle. The resulting resins from both processes can be sold in liquid form or ground down into pellets or powder and then sold to plastic manufacturing companies.

Once the monomers are extracted, they have to be chemically treated to make them bond together and form long polymer chains. This is normally done either through polymerization or polycondensation. In the first process, the monomers are mixed with another chemical that acts as a catalyst and causes them to combine with each other, forming a resin . In the second, the monomers are processed in such a way that they combine with each other and release a byproduct like water.

The main types of raw materials used to make plastic are fossil products, such as crude oil and natural gas , though it can also be made from other things like soy, corn and hemp . These contain compounds called hydrocarbons that can be used to make monomers, which can then be processed to make plastic. This is usually done by cracking, in which the hydrocarbons are either heated to extreme temperatures or chemically treated to break them down into monomers like ethylene or styrene .

The specifics of how plastic is made depends on what kind it is and what it will be used for, but the basic steps are the same. Plastic is made using a variety of chemical and refining processes that turn single molecules called monomers into long chains called polymers. After this happens, the polymers can be molded or shaped into whatever the end product is.

After many years in the teleconferencing industry, Michael decided to embrace his passion for trivia, research, and writing by becoming a full-time freelance writer. Since then, he has contributed articles to a variety of print and online publications, including wiseGEEK, and his work has also appeared in poetry collections, devotional anthologies, and several newspapers. Malcolm’s other interests include collecting vinyl records, minor league baseball, and cycling.

Discussion Comments

anon954822 June 4, 2014 We should use biodegradable plastics.

anon332290 April 28, 2013 What is the method used for making a knob for a saucepan lid and a plastic sandwich box?

anon312563 January 8, 2013 I actually work in a plastic factory. Most of the stuff we produce is made from recycled plastic. We make plastic tubs, milk crates and other containers that companies can reuse over and over instead of using cardboard boxes or even wood skids. This actually helps the environment by reducing the amount of paper and wood (trees) needed to produce them. I know it's not a perfect product, but it really does have some positive impacts on the environment.

anon311533 January 2, 2013 Buy the heavy duty reusable shopping bags offered in stores and supermarkets that you buy for $2 and keep them in the trunk of your car. Then, when you're ready to shop again, pop the trunk, grab how ever many bags you need for your shopping and there you go. It's all about doing the best that you can to not be so greedy with the world, because we all have to share it. So let's do this simple trick to help out. -- Green Peace

anon291219 September 13, 2012 I think we should try to get manufacturers to use the biodegradable plastics whenever possible. For one thing, it will save some of the impact on the environment that comes from harmful chemicals like BPA. Second, we can use the petroleum for other uses like medicines, fuels, etc. and lower our dependence on petroleum. We can't get away from petroleum because it's integrated into every aspect of our lives, but we can be conservative and responsible with how we use it and dispose of it. I would like to see more recycling of it. I know if it's not re-formed into other plastic items it's mainly CO2 and water but we still use a lot of CO2 and as for water, well that's another crises we are facing. We the human race are like locusts devouring all we can without respect for the environment or the limited resources. Like you said, it's we who are the problem. We aren't good stewards of anything, much less our planet or its environment.

anon291051 September 12, 2012 Do you guys really not realize that you're protesting against plastic while typing and clicking and view, as well as computing on plastic items?

anon284915 August 13, 2012 The world would be so much better if people started following people, like the guy in Texas who turns plastic into railway sleepers.

anon220026 October 5, 2011 If we grew industrial hemp, it would replace wood an save the forests, and the seed of the hemp used to make plastics safe. Industrial hemp could help protect against deforestation and the oil used to make plastic packaging. It is a multi-use resource. Industrial hemp could even be used to replace steel and concrete. The news of hemp has been historically and systemically suppressed to avoid competition.

anon178298 May 20, 2011 Several points that people need to keep in mind: 1. Just because you're "green" doesn't mean that you have given up all your worldly possessions and taken to eating mushrooms in the forest. There is more to people's opinions than just black and white. There are more political parties than just democrats and republicans, and there are more viewpoints than just "green or not green". 2. The problem is not that world oil supplies are running low; the problem is that we consume so many resources so damn fast in modern day western society (more particularly American society). All ecosystems are designed to give an organism more or less of what it needs, without giving too much of an edge to any one species. Our unfathomably large resource consumption on a daily basis is a castle made of sand quickly melting into the sea (rest in peace jimi hendrix). Our (humanity's) primary concern should be reducing waste, reusing disposable objects, and recycling everything no longer of use. 3. Lets face it. Very few people in the United States could actually survive in the woods. We (Americans) have adapted so well to modern technology that we can no longer live without it. The reality of it is that unless you move somewhere far far far away, you are dependent upon societies systems. That in mind, people should remember that abandoning all of our modern conveniences all at once is literally impossible. Convincing people to become more ecologically considerate will take time, and so will giving up harmful practices against the earth. 4. Plastic does not harm animals. Idiots who throw plastic into the bushes because they are too lazy to go to a trash can do. Plastics are not the enemy here, friends. Our own behavior and inability to responsibly manage our resources is what will inevitably kill us. Please, just think about it for a bit and together we can make the world a slightly better place one step at a time. --Jacob S.

anon122256 October 27, 2010 It is really hard to make plastic but it can be defined. Look at the top og the page for 'plastics' definition. From Gregg S., age 24

anon118198 October 13, 2010 @post number 67: People aren't saying "John, stop using you're TV it's made of plastic!" They are simply saying, for example to the people who made John's TV, "Can you make it out of something else please?"

anon110094 September 10, 2010 All these "green people" should stop complaining. if you don't want to use plastic, fine. means more for the rest of the world. I'd love to see you wear leaves, not use cookers, not drive not use lic transport, not touch any plastic products, not watch tv or use the internet and you should stop saying we should stop using plastic and stop using it yourself. If you're going to say something about plastics or whatever, do it yourself. apply it to your own lives.

anon108315 September 2, 2010 There is a new world coming so let's manage this one as best we can, without getting all wacky about it.

anon89780 June 12, 2010 in answer to post 52, it doesn't matter about us getting behind it, you have to get the people who can change things to get behind it. otherwise nothing happens.

anon82992 May 8, 2010 "green people" and "not green people" classification. step one of genocide.

anon81547 May 2, 2010 In answer to comment 24: If we use too much plastic we would run out of fossil fuels and there will be no plastic but there would most likely be no stopping of animals dying from the plastic for a long time.

anon81544 May 2, 2010 In answer to poster 24: Even if it comes from the earth we could still use up all of the fossil fuel and we won't have plastic but there will be no stopping of harming the earth.

manny65 March 5, 2010 No person should even be allowed to say they don't care about the environment. We are creating a major problem today that our kids and their kids will have to face tomorrow. Wasteful and harmful habits do not affect the individual doing it, but others will be affected down the line. I'm sure in old days the Greeks and Romans killed people who had similar mentalities. Think of it like this: In America we have the liberty of free speech, but, if you say the wrong thing to the wrong person in the wrong place then guess what? you're going to pay something for it! Of course plastics are highly useful and cheap and we cannot escape them today. But we must recycle, mitigate our use of certain kinds, and develop new materials with less risk and environmental impact. A smart plastic company today would definitely invest in such development. And to the guy who doesn't give a crap about the "stinking' dolphins" -- a pack of dolphins once saved a man's life from a great white shark simply because they knew he was in distress. He was attacked from below while on his surfboard. It was on t.v.; you can find it. The Earth will be fine forever; it's people who are doomed the way we are headed. We all need to be jointly intelligent and proactive on this one; it's a must.

anon66972 February 22, 2010 The first step to improvement is recognition of a problem. I do not insist that we rid the earth of plastic, but rather that we recognize that it has a negative effect and that we have the capability to innovate and change. For those who would rather be right than compassionate, calling someone a hypocrite for being critical and honest does not help the situation. In conclusion, I would say that the root of the problem is not plastic, but rather humanity's wasteful, self centered, and ignorant mentality. Peace.

anon65663 February 15, 2010 Can't we all find a middle ground? Let's face it, we are not going to rid our lives of plastic; it is irreplaceable in our lives. However, the quantity and types are what need to be considered. Not all plastic is recyclable, especially when manufacturers create chemical bonds between HDPE and PS for no reason. There are plastics that do, in fact, decompose, and we should be making a shift in that direction. In re to guy who says screw the dolphins: Do you not realize that we live in an interconnected web of life? We have a symbiotic relationship with the species on this earth. The loss of a species leads to the loss of an ecosystem, which creates a shift in the biosphere. We will make this world unlivable for ourselves if we continue on this path of consumption and destruction. On the other hand, for those more eco conscious people out there: Being overly preachy while participating in hypocritical practices does nothing to sway the masses; it solely leads to more incessant bickering. Let us all practice a little tolerance with one another, and a little discretion in our purchases. Jen- Tampa, FL

anon62037 January 24, 2010 The problem is not plastic. The problem is not any particular resource, for that matter. The biggest problem plaguing human interaction with the environment is our supply and demand global economy. We can manage our resources and create better alloys, for humans and earth, but this is not as profitable as producing low scale, readily available materials. Research costs time, money and resources. If our economy was focused on the availability and usability of resources, rather than profit gained by said resources, we would be better off. Please think about this.

anon60946 January 17, 2010 I think that if you don't care what happens to our planet then you don't deserve to live in it. We all use plastics in our everyday life but if everyone could just try a little harder to stop using as much plastic it would make the world a much better place. Then all the "green people" can stop complaining and all the "non green people" can still use a bit of plastic without being completely arrogant.

anon60244 January 12, 2010 to comment poster no. 31: you don't care about environment? you don't care if it turns into a toilet? well news for you buddy. You're going to be living in that toilet one day. yeah. news flash: dolphins actually are smart. if they had opposable thumbs, they would have built buildings by now.

anon59881 January 10, 2010 First of all, plastic has positive and negative effects on the environment. It can be made from pig urine for Pete's sake, turning toxic waste into something useful. Plastic does decompose, and can be decomposed within thre months with the right microbe bacteria. Yes, it is bioaccumulation in animals everywhere and poisoning them. But who can live without it anymore? Also, people that say we should be without plastic, I dare you not to use it. You wouldn't even have your computer to type this nonsense on. The whole cause of "destroying the environment" via burning fossil fuels, littering/dumping, hunting etc. is solely caused by humans. If all the humans were gone, we'd have no environmental problems.

anon56780 December 17, 2009 as my good friend george carlin said, the earth is fine, the people are effed, but the planet will be here a long time.

anon55520 December 8, 2009 I think the environment is extremely important and if someone wants to die and for the planet to die out then they are stupid. it's people like them who destroy our planet! Anon age 12

anon55387 December 7, 2009 people should recycle plastic as much as possible. kitt.

anon55228 December 6, 2009 all you people should want to save the environment. it will save us and the dying animals!! please help!

anon54716 December 1, 2009 Plastic needs to go. At least make it recyclable.

anon53338 November 20, 2009 no matter what anyone does we still can't save this world from anything that anyone thinks is bad because everything around us is made to fail one way or another.

anon52612 November 15, 2009 I really can care less about the environment. I don't care about the stinking dolphins, turtles or anything else. And I really don't care if they go instinct. I think it's funny that the green people use most all the these products more so than someone like me who takes my own bags to the grocery store. Not because I give a crap about the environment, just it's more convenient for me. The plastic bags are a pain and always break and then take up too much room in my garbage can. However if the entire world turns into a toilet, so what?

anon52506 November 14, 2009 Perhaps all of these anti-plastic, green people would kindly stop using their PC's (which contain plastic) so we don't have to put up with their lunatic ramblings on the internet. :)

anon50930 November 2, 2009 From food-storage containers to disposable silverware, plastic products are such a part of our lives that it's easy to forget they contain chemicals that could harm the environment, and even us. More than 200 billion pounds of plastic, is produced each year, 10 percent ends up in the ocean. Eventually 70 percent of that ends up sinking, which does damage to ocean floor life, and the rest of the plastic floats. About 100,000 animals, such as dolphins, turtles, whales, penguins, are killed every year due to plastic bags. Many animals consume plastic bags, mistaking them for food, and die soon after. The ingested plastic bag remains unbroken even after the death and decomposition of the animal. It lies around in the landscape where another victim may ingest it. ~Elayna, age 16. I wrote a 6 page paper on plastic.

anon50315 October 27, 2009 i can't believe how much plastic we use.

anon47157 October 2, 2009 you try living without the things that modern society provides then talk to me about being so green. plastic comes from the earth, therefore there is no harm in using it if you know how and when to use it. it's certainly better than using light metals. if you compare the process of making them the differences in pollution output are enormous. look at a steel mill then look at a petrol processing plant. i'll bet the steel mill produces more pollution. thanks greenie. that's the problem with you green people. you speak without facts and you don't even take the time to check before saying something is so bad.

anon43842 September 2, 2009 We all should think very hard before we start using food sources for fuel and plastics. It's a recipe for famine.

anon43512 14 hours ago some of this stuff is weird.

anon42121 August 19, 2009 "Green Person": someone who realizes our collective choices have a profound effect on the ecosystem that we are all a part of and depend on. Anti "Green Person": Someone who hasn't realized this fact yet.

anon38051 July 23, 2009 America should make plastic monuments to represent numerous elements of its culture. From grotesque surgery to the credit debts. A plastic civilization. The monuments would last a lot longer than the traditional bronzes.

anon36904 July 15, 2009 Plastic is so green all you have to do is recycle it!

anon31241 May 1, 2009 If plastic is melted down and poured into a mold, why then does plastic partially burn when held up to a flame? Is it possible to re-melt plastic?

anon29027 March 25, 2009 First off its quite obvious that we cannot avoid the use of oil in the society that we live in, but that's not the challenge. The point is that we need to find more sustainable methods of producing plastics, or more renewable materials, such as corn or soy plastic, to move away from the routines we have all created. The aim of 'green people' is to become more conscious of our daily routines and impact on the environment. The shift away from oil/oil based plastics isn't going to be instant. But it has become popular/profitable to be more aware of your actions. Companies are starting to spring up faster and faster that recycle plastics for uses such as plastic lumber, and companies that provide safer and more renewable materials because they see the market for those materials opening up. Just try not to actually do your part to help the movement; be positive and supportive rather than un-knowledgeable; be conscious and aware because oil/plastics are a huge problem in the ways they're used now, but the shift away from that is happening, just be a part of it.

anon28998 March 25, 2009 anon28972- Before you start going off on the "green people" for their ignorance, check up on yours. Wood splinters and metals don't cause cancer in children. The fact that plastic does not rot is the whole problem, because it takes hundreds of years to biodegrade. Billions of plastic items end up in landfills every year and that is an obvious negative. Nobody is suggesting we eliminate plastic but making improvements on it and cutting back use could only benefit everybody (except companies).

anon28972 March 25, 2009 *We certainly wouldn't* be better off. All you 'green people' can't see past your own noses. Look at all the things made out of plastic here. If we couldn't use plastic, you green people would start whining that people were chopping down too many trees and harming the environment. Then, when we use metal, you would be whining about how mining was damaging 'beautiful nature.' If you really are so green, why don't you live your life *naked* outside in the freezing cold? Now *that* would be green. Conventional plastics are a marvelous invention, and metal/plastic alloys are being researched. What makes plastic so 'unhealthy'? Won't your kids get harmed by wood splinters and harmful metals? Everything comes with a price, and the price for using plastic is relatively small compared to the amounts of deforestation you would have to put up with if you want to use unconventional organic methods. Plastics don't rot, and therefore are hugely useful, unlike wood.

anon27928 March 8, 2009 I think if it were illegal too have plastic then substitutes for plastics would be much cheaper. This would then mean we could have more durable items and re-use them, like metal and wood. It would be good for our environment *and* for the health of our children. I say about their health because 75% of plastics have harmful chemicals which can Leach out and our children have a high risk of Cancer and Hormonal disruption. From Martha age 12.

anon27306 February 26, 2009 To Not use any oil? - One being, a Human that is, can't escape oil in his/her everyday life. To escape the use of oil one would have to not get dressed - oil, coal, natural gas after all power even the cotton fabric plants. One would not be able to drive to work on Rubberized/Oil tires, or for that matter even touch the steering wheel - plastic. One would not be able to surf the internet(plastic keyboards) or for that matter use *any* electricity for anything ever. One would have to be naked, own nothing made from any polymers, or use any oil/coal/Nat. Gas in any way to make the items get up with the sun and go to bed with the dark, live in a cave, use leaves and twigs to make clothes. I'd like to see all the "do-gooders" protesting plastic to live like that and report back to this blog telling me how it went.

anon22204 6 hours ago Posted By: Crystal Sempre, 15 But there's new corn plastic out now that's biodegradable!!

eastwest yesterday We would be SO MUCH better off if plastic wasn't so easy to make. It is causing so many problems with chemicals it gives off, how long it takes to break down in landfills, etc. It seemed to be the stuff of miracles when it first came out but that is obviously not true now.

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