Create¶
Learn about the machines and how to make beautiful products
Introduction¶
Overview
Precious Plastic have created four machines to recycle plastic. The ma- chines are designed based on traditional industrial concepts but on a much smaller scale so that costs and knowledge’s entry level can be kept to a minimum. This inclusive approach increases accessibility and adop- tion worldwide. The machines are developed using basic technologies and materials so they are easily understood, reproduced and repaired by people from all over the world with basic metal and building skills. The machines are also built in a modular way meaning that each part is inde- pendent and can be replaced, improved, changed, repaired and main- tained individually without affecting the overall machine. We are always happy to see people hacking our machines and look forward seeing how you can make them better!
In this chapter, we will explain you how each machine works, how to cre- ate beautiful products, how to troubleshoot and repair the most common issues.
How it works
The underlying principle behind the machines is the same for all of them, except the shredder. The machines apply heat to plastic, plastic melts, gets pressed into a mould or shape and is finally cooled to regain its solid state. That’s all the magic behind recycling. Pretty simple, right? Each machine is unique with its own workflows, outcomes, precautions, behaviours and problems but the fundamental concept is the same. The more you’ll work with them, the more you’ll understand them and get better at recycling.
How to get started
Working with plastic is not easy, it takes time and dedication- just like any other craft. It is important you first learn about plastic, the way it behaves and works under different conditions. In the early days of your journey into plastic you should get a feeling of how it melts, how it cools, when it burns and why or how to polish and finish it to make great products.
Beside getting experience with plastic it is also important to develop some degree of expertise on different materials and how they work with plastic. This is particularly important when you will try to make new moulds on your own. Knowing what material conducts heat most effi- ciently, which one releases plastic easily and other key material insights will be crucial to your success.
Before getting started there are a few general things that apply to all ma- chines to take into account:
Read the manual
If you are new to Precious Plastic and recycling always give a full read to this manual. It contains key information about plastic and the machines. This will save you time, help you get the best products, not break the ma- chines as well as keep yourself safe and healthy.
Safety
A number of international research papers have been written on the safe- ty of working with plastic. Opinions are often in contrast on whether heat- ing plastic is dangerous or not. Many researches show that keeping the temperature of the plastic within the melting zone (not burning it) isn’t harmful. This also depends greatly on which plastic type you are working with (this is why sorting is so important). While researching we personally noticed most people working in the plastic industry operate according to this rule. However, not fully trusting the plastic industry we like to keep it on the safe side- always try to avoid inhaling any plastic fumes, wear carbon-mask when working on the machines and make sure there is good ventilation at all times.
The machines work at few hundreds degrees and require people operat- ing them to be always very focused and concentrated to avoid burning or set stuff on fire. Particular attention should also be kept at all times when working with the shredder as its blades are sharp and tend to grab things. Never work with long sleeves or loose gloves with the shredder.
Choose your plastic and start easy
There are many plastic types to choose from. Each having their own prop- erties and behaviours (flexible, hard, liquid etc.). A few are easier to work with because, amongst other things, they have a longer melting zone. We suggest to start with PP, HDPE, PS since they are much easier to work with and will make your life a lot easier.
Temperature
With every recycling process, the first step is to figure out which tem- perature is needed to melt the plastic. Most of the time this depends on the plastic type you are working with and the room temperature at which you’re operating (eg. if it is windy the heat will disperse faster). Unfortunately, plastic is often mixed with additives, pigments and fillers that transform its chemical and physical composition affecting the final melting temperature. Don’t be surprised if sometimes the recommend- ed melting temperature does not achieve the desired molten state, try to gradually adjust your temperature up or down until you achieve the desired melting.
Do not burn plastic
This might seem obvious for some but worth repeating. Plastic should never be burned, at home or while working with Precious Plastic. Fumes from burning plastic are highly toxic and can cause serious health issues to humans. For the recycling process it is also extremely bad practice to burn plastic as the resulting products will be damaged or lower quality. All plastics have a melting zone, which is a temperature window between which they melt (eg. 130 to 171 °C), beyond those temperatures plastic will begin to burn. Try to avoid that at all times.
Moulds
Moulds are an integral part of the Precious Plastic ecosystem and could almost be considered a world on its own. Moulds give shape to the molten plastic and create the final product. Entire teams of designers and engi- neers dedicate their lives to develop moulds to make most of the stuff around us. At Precious Plastic we do not specialise in mould development and open sourcing, yet. Your team should look into ways of creating new moulds to make new products and push plastic recycling to its limits. We share techniques-videos on our website to show you different ways how to do this.
Moulds can be made using different materials but we generally advise to work with metal for its durability and better capacity to conduct heat (more energy efficient). Metal can be shaped in a number of ways, which one you will use depends on what kind of object you intend to make and what technologies you can access. For instance, you could use a more hands-on approach and create new moulds using a welding machine (a bit more rough), a milling machine or a lathe. Or you could create a digital file and use more advanced (and expensive) technologies like CNC (very precise).
We advise to spend some quality time thinking, designing and making an accurate mould so you can create better products. This will pay off in the long run.
Make plastic valuable
We believe plastic should not be seen as disposable and cheap. We strive to make plastic valuable, create objects that last long and that people cherish. Put care in that, love what you create and start seeing pastic in a whole new way to inspire others around the world. Creating beautiful, more expensive and valuable objects will avoid you having to compete with dancing cheap oil prices - people will buy your products because they want it, not because they are cheap. This is better in the long run so you can put more effort in the things you make as you will get greater profit- and most importantly plastic products won’t end up in the environ- ment again.
Share your creations back
Our community is the backbone of the project. Go to our forums (dave- hakken.nl/community/forums) or website to see things made by others and make sure to share back the things you make. Help to fuel the proj- ect forward! Together we can find a solution to the plastic problem that works, is fun and improves everyone’s life.
Take it to the next level Precious Plastic provides you and your team with the basic framework to run a recycling workspace effectively. It is up to you and your team to bring it to the next level. Create new products, new moulds, hack the machines, maybe make new ones, invent, collaborate with other crafts- man, experiment, share your knowledge, teach other people, invent new reward systems to collect plastic or bring new people to the workspace you never know where winning solutions will come from. Be open and collaborative.
Shredder¶
Intro
The shredder machine is a key element for a fully functional Precious Plastic workspace. The shredder enables you to chop bigger plastic objects into smaller flakes that are easier to store, wash and introduce in the other machines. The shredder helps your process to be more efficient and fast. Shredded plastic is easier to work with and melts easier. The plastic industry buys shredded plastic at a price 8 to 10 times higher than not-shredded plastic, making the shredder machine particularly import- ant when selling back to the industry. The shredder is the backbone of any plastic recycling workspace.
Process
When you’re ready to shred some plastic the first thing to do is to choose the plastic type, this usually depends on the quantities of plastic piling up in your sorting bags. Make sure you have enough plastic (of the same type) as the shredder needs a little set up (cleaning) between cycles of different plastics. Once you have chosen the plastic type it’s time to break up bigger plastic objects into smaller chunks that can fit in the hopper. This can be done with a hammer, scissors or a sew depending on the plas- tic. At this point you should also roughly clean the plastic from major dirt, don’t waste too much time on this though (plastic will be washed shortly after).
Now you’re ready to insert the smaller plastic chunks in the hopper and wait for the blades to chop them until small enough to get through the mesh (the mesh defines the size of the output plastic). At this stage, you should regularly check the blades and push the plastic down towards the blades with the provided tool to make sure the blades are grabbing the plastic. Always use extra care when working with the shredder. When you finish working with the shredder make sure to store away the shredded plastic or the next person using the shredder won’t know what plastic type is in the bucket.
Extrusion Machine¶
Intro
The extrusion machine is a very powerful machine of the Precious Plastic arsenal as it can create unique products and can run continuously. Techni- cally, if you have enough plastic and a well-streamlined process you could be recycling 24/7. With the extrusion machine you can create filament, granulate or get creative working with moulds. This machine is also great for educational purposes as the process is very straightforward and easy to understand. This technique nicely blends differently coloured plastics together and outputs a homogeneous and smooth colour, for example, if you mix black and white plastic together you will get a nice and smooth grey output. You can use this feature to your advantage in your designs.
Process
Plastic is inserted from the hopper, gets transported along the barrel by a big screw towards the end where heating bands are placed. The heating from the bands and the mounting pressure inside of the barrel bring the plastic to a melting state (liquid). Once sufficiently melted the plastic can eventually get out through the nozzle in the form of a continuous thread. The plastic thread is then treated differently depending on the wanted outcome.
Create
Once the extruded thread exits the nozzle it can be treated in a number of ways in order to get the desired results. For the sake of this publication, we will only describe the process using the provided mould, other ways to create filament for 3D printing or pellets can be found online. When the plastic comes out of the nozzle it is still semi-liquid (and very hot!), this gives us a few seconds to shape it around our mould. The fresh hot thread coming out of the nozzle is placed around the mould over and over until a new object is created. Hot new plastic and previously layered threads will melt together to create a new solid material. Repeat this process multiple times around the mould and you’ll get a new product. While very straight- forward at first, this process requires a bit of experience and good hands- on approach but anyone should be able to make some cool objects after a few attempts.
Moulds
With the lamp mould from our technique videos you can make a lamp, it is simple and straight forward for anyone to understand how it functions. It is made with steel and can be reproduced by any metal worker around the world. An important aspect to keep in mind is to design the mould with convex walls (not completely straight) to help release the final prod- uct. Technical drawings for this mould are available online.
Temperature
You can set the temperature from the controllers on the electronic box. The heating elements are wired into two groups (Nozzle and Barrel marked on top of the controllers) first three elements (Barrel) should be set at slightly lower temperature than the last one near the nozzle. This is to make sure the plastic gets a last boost of heat right before it comes out. Below you can find a diagram with the best settings for this machine based on our experiments (tip: you could make one of your own to see what works best for you). The optimal temperatures below are drawn us- ing a motor turning at 70rmp. If your motor turns faster you would need higher temperature as the plastic flows faster through the barrel and has less time to melt, vice-versa if the motor is slower. How to operate the extrusion
Injection Machine¶
Intro
The injection machine is a rather fast machine that allows for small pro- ductions of very precise objects. Moulds can be slightly harder to make but once you have a good mould you will be amazed by the products you can make with it. The injection machine can usually make smaller objects depending on the barrel’s volume but operates at faster speed and with high precision. The output colour is often unpredictable when mixing colors in the barrel allowing for surprising patterns that can add to the beauty of your products.
Process
The plastic enters through the hopper filling the barrel until needed de- pending on the size of the object you want to make. The heating elements bring the barrel to temperature and melt the plastic inside. After 15-20 minutes, depending on the plastic type you’re working with and the vol- ume, the plastic is molten and ready to be injected into the mould using the hand-powered metal lever. Right after the injection the mould can be cooled, this can be done either with air or cold water (faster but can cause rust). Wait until the metal is cold and you’re ready to open your mould and see the results.
Create
Creating products with the injection machine can be a little more difficult as it requires a good mould upfront. Depending on the type of plastic the lever can be pressed by one person or two if more pressure is needed to inject the plastic. The process in itself is tightly connected with moulds and mould making. If you have a precise mould you can create beautiful products in a matter of minutes and start a little local production. Before injecting the plastic in the mould you have to make sure that the plastic in the barrel is fully melted in order to fill all areas of the mould. To achieve this run the ma- chine a few degrees higher than usual to certify the plastic is fully liquid.
Moulds
With the tile mould from our technique videos you can make octago- nal tiles, it is simple and straight forward for anyone to understand how it functions and can work beautifully in series. You can make facades, pavements or tables- we can’t wait to see what you can do with them! The mould is made welding different steel parts together and can be easily reproduced by any metal worker around the world. We highly encourage you and the team to look into making new moulds to create products that fit your market. Technical drawings for the starter mould are available online.
Temperature
Below you can find a diagram with the best settings for this machine based on our experiments (tip: you could make one of your own to see what works best for you). You can set the temperature from the con- trollers on the electronic box. The heating elements are wired into two groups (Nozzle and Barrel marked on top of the controllers) with different temperatures, first three elements (Barrel) should be set at slightly lower temperature than the last one near the nozzle (Nozzle). This is to make sure the plastic gets a last boost of heat to get more liquid right before being injected into the mould.
Compression Machine¶
Intro
The injection machine is a rather fast machine that allows for small pro- ductions of very precise objects. Moulds can be slightly harder to make but once you have a good mould you will be amazed by the products you can make with it. The injection machine can usually make smaller objects depending on the barrel’s volume but operates at faster speed and with high precision. The output colour is often unpredictable when mixing colors in the barrel allowing for surprising patterns that can add to the beauty of your products.
Process
The plastic enters through the hopper filling the barrel until needed de- pending on the size of the object you want to make. The heating elements bring the barrel to temperature and melt the plastic inside. After 15-20 minutes, depending on the plastic type you’re working with and the vol- ume, the plastic is molten and ready to be injected into the mould using the hand-powered metal lever. Right after the injection the mould can be cooled, this can be done either with air or cold water (faster but can cause rust). Wait until the metal is cold and you’re ready to open your mould and see the results.
Create
Creating products with the injection machine can be a little more difficult as it requires a good mould upfront. Depending on the type of plastic the lever can be pressed by one person or two if more pressure is needed to inject the plastic.
The process in itself is tightly connected with moulds and mould making. If you have a precise mould you can create beautiful products in a matter of minutes and start a little local production. Before injecting the plastic in the mould you have to make sure that the plastic in the barrel is fully melted in order to fill all areas of the mould. To achieve this run the ma- chine a few degrees higher than usual to certify the plastic is fully liquid. Moulds With the tile mould from our technique videos you can make octago- nal tiles, it is simple and straight forward for anyone to understand how it functions and can work beautifully in series. You can make facades, pavements or tables- we can’t wait to see what you can do with them! The mould is made welding different steel parts together and can be easily reproduced by any metal worker around the world. We highly encourage you and the team to look into making new moulds to create products that fit your market. Technical drawings for the starter mould are available online.
Temperature
Below you can find a diagram with the best settings for this machine based on our experiments (tip: you could make one of your own to see what works best for you). You can set the temperature from the con- trollers on the electronic box. The heating elements are wired into two groups (Nozzle and Barrel marked on top of the controllers) with different temperatures, first three elements (Barrel) should be set at slightly lower temperature than the last one near the nozzle (Nozzle). This is to make sure the plastic gets a last boost of heat to get more liquid right before being injected into the mould.
Final Thoughts¶
The above processes are a starting point, not an end goal. They should inspire you and get you started, spend some time mastering them. Once you’re confident you understand how they work and how to work with plastic why not trying to go off road and test new ideas, moulds, process- es and techniques?
We look forward to see where you and your team can take this project, pushing the limits of plastic from Kenya.