🇪🇪 Precious Plastic Estonia
Today we have built the shredder and did a test run. A couple of things still to be tweaked, but overall we managed to get our first batch of shredded plastic.
Thanks to @davehakkens and the team for making this possible.
We would be happy to help anyone who is planning to start building the machines soon with some before-assembly advice.
December 2017 update: Shredder, Injector and 5/7 of the Extruder ready.
January 2018 update: Moving part of the production to Tallinn.
March 2018 update: The last – Compression machine almost ready.
Estonian team: @jegor-m; @maximmm; @igor-smog; @dannydadog
Instagram /// Facebook page
Good first results! What is the thickness of the coasters ~6mm?
Can you show us the mould attached to the injection nozzle (held by pressure)?
A quick update:
1. NGO registered; Bank account registered; Meeting the representatives of the Producer Responsibility Organisations soon.
2. It has been a while for sheet press action for us. We fired up the oven, got some plastic in, waited a bit and pressed the molten pile between the metal plates in the sheet press, like before. This time we used regular office markers (Photo 1). You might have seen these shredded in the earlier photos.
What we got is shown in Photos 2-3. Thin sheet of PP, very multicoloured. Thickness 1-2mm. On the photo you can see some wrinkles and creases. This is due to top metal plate sliding and baking paper creasing while it was transported from the oven to the sheet press (literally 1 step, managed to mess it up)
The apparent dirt is not dirt at all. It is all the black ink that you can see on the Photo 1. The barcode and the text got shredded and are now inside the plate. Looks like dirt. Not cool.
Next, Photo 4 is a quick mock-up of what a wall clock made of this sheet would look like. We have not yet decided to turn it into the wall clock though.
3. Photo 5 is a teaser for our extruder. It just needs some drilling, polishing, electrics set-up, painting, re-grinding, re-painting and testing.
For now: we increased the barrel diameter, auger bit is 32mm in diameter. Will see how it turns out.
FYI, on the last photo – it is Max ( @maximmm ), add him as a friend. He’ll be super happy.
Awesome!I could watch that for ages.
Question on your remark concerning the overheating with bubbling…
Do you mean that over temperature result the bubbles? Not only the burn…
Thanks for your feedback
Yes, there are a couple of factors that contribute towards bubbling.
If you’re not compressing the plastic for example, then the air trapped between plastic pellets just stays in place and eventually turns into bubbles.
If you badly overheat the plastic, then bubbling will not be a problem as you will simply burn it. But if you go high above the melting temperature, you might get more bubbles in the plastic, even if compression is involved.
PS. Please use @ and a nickname to mention a user. This allows monitoring updates more easily.
A friend of ours gave us keys to his small damp garage in Tallinn that we are going to use for production. In a month or so we will try and get the machines in and will be ready for visits.
In case you’re planning to come over to Tallinn 🇪🇪, give us a shout.
The garage is slowly getting into the right shape, machines coming in..
👍 really cool!
Great work so far, I will be keeping an eye out on this thread to see how your machinery and processes progress. :o) I hope setting up your workshop in Tallinn is the start of something new and exciting for you.
@jegor-m This is a really great story, full of details. I have a question, for big pieces of plastic recicled by extrusion (bigger than the aluminium can) you mentioned that it has to cool down slowly (p.e. in the oven), right? If we apply some pressure and always with a controlled temperature (I mean avoiding overheating), do we still need to cool it down slowly?
I hadn’t look at this thread, you got a great information repository here. I had the same problem with PET bottles sliding into the edges of the shredder knives. I was planning to melt the bottles in an oven prior to shredding them to avoid this issue but haven’t had a chance to test this out yet.
Winter in Tallinn = cold. But we are working!
Yeah, same here in Dresden. Freezing cold…
Our solution -> Building the Compression:)
And you have pictures?
🌎Update N.17 (1/2) – PP Coasters
Over the last couple of weeks we have been testing the injection machine. For that we made two metal moulds and one acrylic mould (plexiglass).
What you need to know is that the ambient temp. in our garage is about 0°C.
The first photo shows the coasters we got.
Pictures 2 and 3 show the first try using metal moulds. Temperature set for a bit over 200°C. This is mostly due to the fact that it cools down quite fast in such a cold air.
Result – pretty nice coasters with minimum post processing / finishing up.
What could be done better? – wait more time to get uniform melt – better surface.
Pictures 4 and 5 show a second attempt. Process temperature was lowered.
Result – as you can see both of the coasters are not finished. This is mainly due to the fact that the mold is cold and plastic cools down and solidifies before reaching the furthest wall. Before you say it, we actually wanted to put the injection point to the side, to get plastic to flow in weird shapes and colours. The smaller coaster, if it can be called a coaster, has dark lines. This is because of the leftovers after the previous batch (pic 2 and 3)
What could be done better? – Faster injection; Longer wait;
Also a good idea is to add an indicator hole, that would show that the mould is full and it is time to stop pressing.
*acrylic mould has not been tested properly yet.
🌎Update N.17 (2/2) – HDPE Coasters
Next was a test of grey HDPE. Three temperature sets were used (170/180; 190/200; 220/230 °C). The results are shown in the photos attached (in the same order).
We added some pieces of bottle caps (white, blue and yellow) just to give it a bit of colour. At least we tried. This set of coasters got a very rough texture. It was very hard to push into the mould.
Surface flat and low roughness. Warping due to increased temperature becomes visible. Injection was not performed in one movement. It was paused for a second and then continued. This is clearly seen from the injection lines on the coaster. Second one is not filled as it got too cold to flow.
Our metal mould is far from perfect. If more plastic is squeezed into the mould, it would fill every corner. This try was done with the most heated HDPE, hence better flow. The overheating warp is quite bad on this one.
What could be done better?
Perfect temperature range is yet to be established.
Injection has to be in one quick move.
Indicator hole should be a good way to see if the mould is full.
Ambient temperature has to be adequate.
Mould temperature to be at least 20°C (better if 30-50°C)
All the coasters up until now. Only 3 of good enough quality.
Nice work, I like your documentation.
Wow!!! I would love to start this where I’m living. My idea was to collect plastics that have washed up on the beach but after reading realize certain plastics melt together more smoothly than others. Gosh where do I even begin?
General practice is to avoid mixing various types of plastic in one item as it makes it unrecyclable and cannot guarantee item’s structural integrity. It might just fall apart as the bits won’t stick to each other.
Smoothness is mostly controlled in the fabrication process itself through setting the right temperature; having a smooth mould etc.
The first step is to separate the plastic. By product type first, then with some research by material type as well.
Also don’t forget there is so much information here on the forum, look something up.
Good luck with your recycling!
🌎Update N.18 – Extruder
Eight months ago we had our first meeting and a casual discussion about the possibility of starting a local Precious Plastic branch in Estonia.
Today our garage has an injector, shredder and an extruder. The latter is still to be tested with plastic.
Future plans include building a compression machine (fancy oven) with rotomoulding capability, a small PET bottle shredding machine, may be also a long (limousine) oven for the longboards and a vacuumforming machine. We’ll see how it goes.
Like always awesome!
🌎Update N.18 – Bottle caps
We sorted the bottle caps by colour, with blue being most common.
How do you guys deal with the rubbery layer inside the bottle caps?
Current plastic stock status in the photo.
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