 Hey, I'm Jerry and welcome to a new Precious Plastic video. In today's video, I will tell you a bit more background on plastics. How they came around, how they are produced and what happens after they are discarded. This video consists out of three chapters. The first chapter is general knowledge. The second chapter will be industrial production methods and the third chapter will tell you the afterlife of plastics. And this video comes together with a web page where we give more background information on the various topics. The link is down in the description, so make sure to have a look. So, plastic got a real head start halfway through the 19th century. When they tried to find alternative for billiard balls. These used to be made from ivory, from elephants and that caused mass slaughter of the elephants. So the initial use of plastics was quite a noble pursuit. Where back then it was just a couple of different types of plastics. It's now an industry of billions and there are thousands of different types of plastics. But what actually are these plastics? So another word for plastics are polymers. Where poly stands for multiple and merges for units. These units are monomers and these are small groups of atoms. These atoms are often made from fossil fuels in a process called cracking. And if you chain these separate monomers together into a long chain, you get polymers. So these are very long strings of plastics made of polymers. So with plastics you have three different groups. Thermosets, thermoplastics and elastomers. Thermosets are sort of a one-time use plastics. Where you mix two materials together or you heat something up. It forms a lot of these small cross-links and then it turns into a new product. You can sort of see it as an egg. Once you boil the egg, there's basically no way back. You cannot un-boil an egg. So if you look at that for plastics, you can see an example here. If you were to heat up the plastic again, the plastic would not melt. But you would see that over time it will burn. And probably the most common termoset is polyurethane. This can be found in insulation but also in mattresses or shoe soles. So here you can see that the polyurethane is not melting but it's burning again. So this is not possible to reuse once the plastic is cured. Here you see a thermoplastic. And once you heat up the thermoplastic, it starts melting again into a liquid. And then you can reshape it in contrast to the thermoset where it would just burn over time. Another type of plastic can be melamine. This is often used in kitchen tools. It's heat resistant but also again only a single-use plastic. But also for example, bakelite used in these old telephones is used as a thermoset. But luckily by far the biggest group of plastics is thermoplastics. And these plastics do not form these small crosslinks. And that makes it possible to heat it up again and to melt the plastics. And this you can sort of more see it like chocolate. So once you heat up the chocolate it melts and you can reshape it. And here at Fresh Plastic we like chocolate more than eggs. So with thermoplastics you have a lot of different types of plastics. You have for example PET, PP, PE, PS and also PVC. All of these different plastics have their own unique properties and they even got their own recycling logo. As you can see for example here or inside here. So more on these recycling logos later. These are not all the thermoplastics. There are also more engineering plastics that have unique properties and that are a bit more expensive. For those you can think about PMMA, PC, ABS, SUN, POM, PEEK or PEI. All of these plastics give unique properties but once they are recycled they all need to be separated in these different categories. Next up you have elastomers. With elastomers they are somewhat in between the thermosets and the thermoplastics. Where they do have some crosslinking in between the polymers but not as many as the thermosets have. So examples of elastomers can be for example natural rubber, silicone or for example neoprene which you see in wetsuits. So these are the three different types of plastics and something that is not a plastic by itself which is critical for the plastic industry are additives. Often additives are added to the plastics in order to change its behavior. This can change the plastic in making it more flexible or stronger, flame retardant. But also something as simple as just coloring it or filling up the material. And these additives make it super difficult to recycle because nobody knows which additives are added to the plastics and nobody writes it down on the product itself what additives are added. But there is one exception. So you also have these glass fiber reinforced products which are often seen in industrial tools which make the product stronger and more rigid. Often they mark the plastic with the type of plastic but also the ACF or GF marking for glass fiber or carbon fiber reinforcement and then a number behind this to indicate the percentage of the fibers inside the plastic product. These make the product a lot stronger but for this the length of the strains and the direction of the strains are important. But more details like these can be found on our web page. So make sure to check it out. This was it. A general introduction into the different types of plastics. Now we head over to the next chapter where we talk about the different industrial production methods used for making plastic products. Now I'm going to tell all about the different production methods used in making plastic products. But before I can tell about this we first need to look at the raw material. So for plastics this is often granulate and after the polymerization process the plastic is chopped into small beads or flakes and these makes it possible to easily store the plastic transport it but also melt it very easily. But if you want to make something from recycled plastic you do the same. You first shred the product that you want to recycle into these small flakes and from there you can easily transform it into a new product. Probably the simplest production method is extrusion. As the name implies the plastic is extruded out of a die and this makes this long continuous plastic product and this process consists out of three parts. First you have the feet part where the plastic granulate enters a special screw and the screw moves the plastic forward all the way up to the die and the shape of the screw is very important because it changes diameter over time which puts the plastic under a lot of heat and pressure and this results in a fully molten plastic once it reaches the end of the screw. From there it enters the die and this defines the final shape of the product. So if you want a square product the die is square but if you want a hollow product then you have a hollow die and this is probably the most common product made with extrusion. So these are tubes. For tubes you need a special torpedo die that spreads their plastic evenly around the die in order to create a constant tube and with these tubes you can do a lot of things. You can either extrude it for long meters but you can also still use the plastic while it's still warm to use it for blow molding. With this the warm tubes enter into a new mold and there with the help of compressed air the plastic is formed into shape. Not only you can make small parts from blow molding but you can also make these very big products from blow molding and that makes it possible to have these big quantities of plastic. Another process that is a little bit more complex is injection molding. For injection molding plastic is injected into a mold and from there it solidifies, cools down and it keeps the shape of the mold. So with injection it also consists out of three parts. You first have the feet part then you have the mold and you have the clamping part. The feet part is similar to the extrusion where a screw moves the plastic all the way up to the mold. The clamp ensures that the mold is clamped down and no plastic leaks out of the mold and then in the end you have the mold and here you can see a small example. So plastic is injected on one side into the mold and then once the plastic is in there plastic is injected in one side into the mold and it reaches all the way inside of the mold and there it fills up the mold cavity. This part is fixed to the machine and this part moves every time a new product is made. Once the mold is open and the plastic is cooled down you have these small ejector pins that eject the product out of the mold and then you can make a new product. In order for the plastic to reach all the way into the cavity you need something which is called a sprue and this sprue ensures that the plastic reaches from the feet all the way up to the product and before it reaches the product there's a small gate that makes it possible to put a lot of pressure behind the plastic and that ensures a good fill of the mold. So here you can see a product where the sprue and the gate are still attached but normally with other products it is all removed and you don't see anything from this and with injection molding you can make a lot of different products for example Lego bricks, household items but also toothbrushes or CD cases and in the end you can make the mold more and more complex in order to make more complex products like for example this one In order to make these plastic products there are a couple of design guidelines and these make it possible for a plastic product to be injection molded The exact design rules we will not cover now today in the video but a lot of other people already documented this very well so we will link these in the web page A process that is a lot simpler is thermo-forming Here sheets of plastic are extruded and heated above a heater and then moved to a mold where it is stamped into shape So you can see for example these simple tin-walled plastic products and they are often thermo-formed and with this process you can make a lot of different simple products in big quantities After it's stamped then it only needs to be trimmed and then it's ready to be filled or ready to be packaged So something that you don't see every day is rotation molding These are often used for low volume series but very big products and with this rotation molding process you first fill a mold with powdered plastic then you heat it up while evenly spinning it around all the access After it's fully molten you cool it down while keep spinning it on all the different access and then you unpack it The upside is that you have a hollow product and it's really fairly easy to make a mold for this because it doesn't need to withstand all the pressure from the other methods The only downside is that it takes quite a long time and it's very labor intensive but you can make very big products out of this A relatively new process is additive manufacturing Here multiple 2D layers build up a 3D shape and the advantage of this is that you don't need a mold for every product so you can change every single product and adapt it to the end goal of the user The only downside is that it often takes quite a long time before all these different layers are built up Since this additive manufacturing is still a relatively new technology you often see different types of 3D printers and also different materials so most common household waste is not able to be 3D printed So with the 3D printing you see a lot of different techniques but they also require different materials all with their unique properties but also all of them need to be separated at the end if you want to recycle the products Apart from all these automated processes you can also do more manual processes where you can turn the plastic on a lathe you can mill it, you can drill it, sand it and that makes it possible to have these unique applications for plastics Here it becomes more like a craft and we made some cool how-to pages on the website for new applications So this was it for all the production methods I hope you learned something More info about all of these is on the website And now let's head over to the last chapter which is plastic recycling Here I tell you all about the different things that happens once the plastic is discarded In an ideal world, all of the plastics would end up somewhere here where it's collected, sorted and then turned into new products But currently a whopping 2% of the plastic packaging is recycled in a closed-loop recycling That means that 2% of the packaging is used again for packaging Another 8% is used in cascaded recycling or downcycled where a lower value product is made out of the plastic The difficulty arises with plastics that consist out of different types of plastics and that are difficult to disassemble or difficult to identify So industrial companies made a couple of different methods to sort the different plastics This can be density testing, burn testing, infrared testing, static testing but also hand sorting So I will show you some small examples and then we see how difficult it actually gets to recycle and sort the plastic So probably the simplest method is density testing where you have two different plastics and you want to separate them You find a liquid that is in between these densities and then the lighter plastic is floating to the top where the heavier plastic will sink to the bottom and this makes it possible to separate two types of plastics But often the plastic you get in is a mix of multiple plastics and with this you can only separate two of them and then you would need to do it again with a different liquid for other plastics So this will result in a very long process Something that is often more effective is infrared testing where you shine a light on the plastic, it reflects and because of every plastic having a different molecular structure the response of the reflection is different and with this you can measure the unique response and identify what plastic it is but the downside is that the dark pigment changes the response and this can lead to misidentification of the plastic Currently we are also working on open source alternatives for these automated processes in order to make plastic separation easier So another method to identify different plastics can be with static testing So let's give that a try You first make something very static and then you move it over the plastic and how much the plastic is attracted indicates the different types of plastic But again due to these additives for example this can change the properties and make it less static misidentifying the types of plastic Another way could be for example burn testing where you have a sample of a product you burn a piece of it and based on the properties of the flame or the smoke this indicates what types of plastic it is Big downside is you need to burn the plastic and we definitely do not recommend this Last up is hand sorting and here people stand next to a conveyor belt and they pick out plastics that they know or where that has the logo on it and that gives them an indication on what type of plastic it is The problem with this is that often sometimes plastics can feel and look the same even be the exact same product but still be made from two totally different materials or people look at the marking that is on the plastic The only downside is that it only was introduced in 1988 so not all of the products have it and up till now it's still a voluntary system and also around the world they use different identification logos to mark the plastic so this also makes it more complex to identify the plastic So the only thing left is identifying the plastics with the help of some tests Something that you can remember is that chemicals are often stored in HDPE bottles because it's very chemical resistant PEP for example can have this life hinge where you can flex it multiple times without breaking For both HDPE and PEP it is semi-crystalline plastic so that makes it possible that the plastic is translucent but never clear like transparent So the difference between PEP and PEP is that if you hammer it the PEP will shatter on impact where the PE will just deform and will not break Another distinction to make is for termoset plastics So if you think a product is made from a termoset material what you can do is test it with a knife and scratch it and as soon as you scratch it you can look at the surface and if it gives these small flakes or particles then it's a termoset where if you were to cut a termoplastics this will only give a very clean line and will not give these small particles So this gives an indication on how complex it is to sort these different types of plastics and an alternative to this would be a more circular approach where not only the product but also the process is changed Something that gives an indication into this can be for example deposit PET bottles but still very difficult and only a limited percentage of the PET bottles is again used in PET bottles often it's made into yarn for fabric I hope this gave you some insight into the different types of plastic and how difficult it is to recycle these More information will be on our webpage and see you in the next Brush Plastic video Oh wait just before you go we just wanted to let you know that Precious Plastic runs on the support of people just like you Everything we research and develop we release open source online for free Go to support.preciousplastic.com to make a donation or find other ways you can help