In this, my first topic, i am going to share my first plastic projekt and product:
These Tealight Holders: (pic below)
As i started of without any of the precious plastic machines made by @davehakkens
I will show you a little “howto” make them with only a solid pair of hands and a minimum of tools.
Maybe this will spark some inspiration to those who want to get startet making products and experiments with plastic, but is yet to build the machines.
Friend i’ve been melting and experimenting with: @clementhempel
When starting the projekt i chose to work with HDPE.
It was recommended by my friend, and i will recomment it to you
As the plastic was easy to collect, easy to clean and easy to process.
You can find HDPE everywhere in your household, bottlecaps, shampoo-bottles and pill-bottles.
I made this picture with a visual of different items that is made from HDPE (pic below)
– If ever in doubt just look for any of the triangels.
For me all the different triangle marks have been melting together just fine, but i would like to know if there is any major chemical differenses?
As i said before, the inner button was a hard to reach area.
But as i just bought this grinding tool, (picture one) the problem saw its solution.
It was sanded twice, first with a rough, and then with a more fine stone.
A before picture with an other tealight holder (picture two)
A after picture with the final sanded button (picture three)
I just ordered some of the marking coins made by @davehakkens and the rest of the precious plastic team at the HQ.
As i am working on a low budget i will show you a low budget way to put a stamp on your plastic.
(Picture one)
There is five different coins, and we are going with the HDPE coin.
(Picture two)
The good thing about making tealight holders, is that i could hold the tealight while it was heating the coin up enough to melt the plastic by contact.
(Picture three)
The stamps are looking great, and makes you remember what kind of plastic you used, while showing others that the product is recycled by the principles of precious plastic, that is collecting, shredding ect…
Good luck with your experiments @pe-trhlinka ! I am looking farward seeing your results
And no problem, if i can just help one guy with answers it will be Worth it.
Give the manual shredding a go again with a better pair of scissors and start some experiments, you will have far better knowlege to when you have the shredder redy
Good luck!
Thanks for the detailed answerd I hope it will help someone else too I will post my results soon I hope… I really need a shredder first, tried manual shredding but it is so time consuming
Hi @pe-trhlinka !
Sure thing, just wanted to make everything 100% clear to avoid any misconception
Pressing the board would be an option, you might run the risk of it getting stuck in the mold, but go for it! I cant tell for sure what will happen
Question: Will heated plastic bond with cold plastic?
You are right that when the plastic is proper hot you will be able to weld it together. But i am quite confident in telling you that it will not work with just one part being hot. Off course i am only speaking of experience and has only experimented with 180’C – 200’C but if it gets more hot, it might behave differently
If you want to weld plastic i did some tests Test one
Tried to weld plastic with a heating gun, but even as the plastic gets soft, it just wont stick together
Test two
Heated the plastic ends that i wanted to fuse with a toaster, and would you look at that, a perfect welding!
Proof that it works: (another guy welding with an iron for hair)
In the first post you wrote that you press the material with hammer during adding new plastic so I thought you could press it with the profiled board during the process not just during the final pressing. I didnt meant liquid like water but heat changes the viscosity of the plastic for sure… If you press the two melted pieces of plastic together the form tight joint right? But what if one of the plastic is already cooled, will it bond together?
Its nice to hear that you want to experiment with some plastic in the oven. Because that is what i have been doing for over a year now (also in my parents oven). I can confirm, that if you arent like burning the plastic in the oven, none truely unpleasent smells will appear. The plastic scent or smell will not, and i repeat, not stick to the oven or kitchen, just vent the room after melting.
The board-idea would probably work, as it is only used as the last step just before cooling of the mold. Not in between.
You talk about the plastic being liquid, – it will not be liquid at 180’C
The only thing i can make a comparison to is chewing gum, the pickture below is meltet plastic (botten) and new halfway meltet plastic (top) in the oven on top of some baking papir, and none of it is dripping or spreading off the papir. It will only turn soft and sticky so that it mixes together.
Thanks for answering so quickly so the whole process of melting the plastic would take about 90 minutes in total? After reading the data sheet I think that it’s not so bad to do in your kitchen, but my mother would kill me if I ruined her oven with plastic smell yes the drawing is exactly what I thought, I dont know if it would work or the plastic is too liquid during melting that it wouldnt hold its shape between adding more plastic and compression… I discovered preciousplastic recently so I didnt even started building any machines but I would like to try some recyclicg as soon as possible
Hey @pe-trhlinka that is some great questions, and i will try to answer them at well as possible
First question: Melting the plastic
– When i did the melting-process at 180’C, the plastic was heated up about 3-5 times to apply extra layers. From an cold oven and cold plastic i would give it maybe 15 minutes depending on the amount of plastic, and then 8-12 minutes to keep it warm after applying a layer.
Second question: Horrible fumes
– One of the resons i picked HDPE, is that if you are melting on an small scale in an oven as i did, only a microscopic amount of fumes will be released from the plastic when melted. It may give of a little smell of plastic, but just be sure to open a window and you will be good to go.
Here is some safety hazards, but bear in mind that this is made for the industry where plastic is heated more then 180’C
Third question: Profiled wooden plank
– I am so glad you suggested this, it seems like a good idea, to skip the steps with the woodworking tools. This will be possible, when the plastic is molten enough it will act like chewing gum and will be pressed down by the board (yellow thing on the drawing) just fine.
Just to be sure what you mean, i made a visual of what i gues you are trying to suggest (pic below)
To make kinda like a Lego and then cut out the 3 finished Tealight holders?
It looks great! three quick questions, how long did it take to melt the plastic? Did melting produce any horrible fumes? Would it be possible to use profiled wooden plank so that you would mold the final shape with every compression? Thanks for the answer
Hey thank you @flo-2 !
These tealight holders startet out as a hobby, but just ordered some lasercut parts to build a shredder. I hope to maintain the look, as the efficiency goes up
@anris Wow! I’m really impressed by your products, especially that you can make these awesome-looking things without a big machine! Great work! I love it!
When no injection or compression has been done to the plastic, the tealight holders has these spotted patterns.
– This was done to show that with just an oven and some plastic, you can still recycle on an small scale
– Enjoy some final picktures
I found that 180*C works great when melting in a standart oven
To make all the plastic fit into the form and stick together i did these 3 steps repeatingly
– Heat up the plastic
– Press it down with a stick or hammer
– Add extra plastic
Until your block is at your desired height (picture one is from Snapchat and says “we made a plastic bread”)
Now you just need you saw the block into desired shapes and sizes (Pickture 2)
I worked with woodcutting tools and found that it gave the block an interesting texture. (pickture 3)
The toughest part was to smooth out the button of the tealight holder, maybe some of you have an idea?
If you do not have a shredder, you need to cut your plastic by hand
For making the tealight holders, we dont need any fine granulat, and by cutting the plastic into pieces just as big as the bottle caps, it will work out just fine.
Use strong scissors / something like the tool on the first pickture
It is used for cutting scrapmetal, and it is perfect here (you can find it online or at your local store for around 5-10€)
Our goal is to fill a breadform with plastic and melt it into a bar.
The bar can then be processed with normal woodworking tools to make the Tealight holders.
The picture below shows our molds and the various sizes of plastic we have been using. The wooden plank is to make the final clamping and squeezing so all the plastic comes together as a bar.
I will post my results soon I hope… I really need a shredder first, tried manual shredding but it is so time consuming 
