Heat press machine
Hello fellow humans,
I have recently brought a heat press machine, I have seen a few people using these to make sheets and now want to have a go myself.
I’m really excited to make a start at this see what I can make with it.
If anyone has any pointers or tips they would like to share that would be amazing.
Stay safe and keep up the good work.
I cut my first sheet down into a 15cm2, this was the smoothest part of my first sheet.
I got 2 silicone baking sheets (thanks for the tip) molded with aluminium tubes again this time to the length and width of the baking sheets. 21cm by 38cm. 20min each side then 10min under a large weight.
The mold moved and didn’t keep the plastic in the spot as you can see. But over all very happy with it. Smooth and strong, wanna try and build with this soon.
Hi Adz, @adzie23
We have been using a heat press at our regular Plastic Playgroup events, and have figured out a few tips though we’re far from totally figuring it out.
– We use silicone baking mats to prevent the plastic from sticking to the press itself, initially we used parchment paper but it crinkles the surface when it cools
– As Morethantencents suggests, we put the hot sheet straight under a flat sheet to prevent warping as it cools. We use a big book but have been donated a book binders press and are going to try that next time since it can also give us some control over thickness. Ideally you want equal cooling rates on top and bottom, so if you place it on a cool surface but insulate it using a book above (as we initially did), it is likely to warp. Better to use two books, or something else of equal temperature and thermal conductivity, then wait longer for it to cool.
– Because this type of press is hinged at the back, the sheets will be thicker at the back and this effect gets quite significant even aroud 2m thick. To get around this we chock up the front underneath the bottom plate. On ours it has two bolts at the front, which can be loosened and washers or other stops can be wedged in to raise the bed at the front. We haven’t got a science for this but in time we imagine we’ll know if 3 washers suits 4mm sheets, 6 washers for 7mm sheets for example.
Attached are pics of PP and PLA sheets made using the press – we’ve got up to 6mm by doing it in layers, adding flakes that melt to add less than 2mm at a time. I’d be interested to see how you reach 10mm without it being super labour intensive. The one pictured has warped a little when cooling.
Hope that saves you some time. Can’t wait to see what you make!
So been experimenting all today and have finally worked out my warping problem, well a large part of it. Made 2 really good sheets that are smooth. Made a little table with 1 of the sheets, super stoked with it!
200c for 20min each side, cooled down under a concrete slab.
Shiny finish, smooth to touch, very strong.
21cm by 33cm by 1cm. More to come.
Cant wait to see your results Adzie, someone donated us an old ironing press, I modified it a bit so it wouldnt switch off when it got ho and made some half decent sheets in a quick experiment.
My only suggestion would be, use thin tin sheets to sandwich the shred inside the press and then when you take it out, put it under a flat weight. The thin sheet wont take much extra time to heat up but it will help the plastic cool slower. This worked in my little experiment (wish I took pics now!) to stop it curling/buckling as it cooled.
Thanks for starting up this thread @adzie23 I’ve recently purchased a press to try and make some sheets. Welcome to the family Percy Press 😁👍
I’ve left my Instagram account here too so people can see what else i’ve been making from recycled materials and i’ll post updates in this thread too if thats ok.
Little table looks great!
Did you just add more weight to the slabs to reduce warping, or is there more to it?
My first real test and I’m happy with the results.
A lot to learn from this but just happy to have a start.
Test #1 200g of mixed plastic (I think it’s hdpe)
200 degrees Celsius for 20min.
Inbtween aluminum tubing to make a 30cm by 15cm by 1cm sheet.
This seem to almost work, the tubes are not welded together so they moved to easy.
Once I have the mold welded together I am going to try again, however after 20min I waited 10min for the sheet to cool in the machine still pressed then took it out and placed a large stone tile on the sheet to weight it down.
Over all happy with the first test and can’t wait to see what I can make.
Over here in the Philippines we have been working in the mad scientist lab to make large numbers of plastic sheets.
We finally achieved success today.
One issue was warping.
Second issue was we was breaking car jacks making sheets
third issue was our sheets were not even thickness.
So We came up with this machine.
We melted in the extrusion machine into a turbo cooker (to keep warm while the plastic acumulated)
We then pressed with 3 ton jack with a press that was cold. We used fans on the mold to rapidly cool the plastic under pressure.
Results were a textured plastic sheet.
We are still working on surface finish, however we find that galvanized steel is virtually non stick to molten plastic.
We need to acquire larger sheets of galvanized steel to test out with larger shots, however in small shots, we had glossy plastic sheet finish.
For joining the parts you can check out plastic welding.
here is a example, but there are lots of others out there.
I modded a large soldering iron to weld plastic and used a dedicated plastic welding machine
in the video they show using a mesh to join parts. I used drywall fiberglass joint mesh successfully in the same technique. Avail in big rolls at your hardware.
As the heat press only heats from the top, and the hot side warps more I tested an idea – what if I make this hot side cool the fastest? – after the sheet is done in the press I place the sheet hot side to my shed floor and add 2 slabs and 16kg of weight on top. Seem to work well
no I haven’t but I do fine that the drill shavings and plastic saw dust comes out really well, as I am only using a house hold blender at the moment it’s cuts the plastic up okay enough for the molds and sheet I’m trying to make I will now save all my smaller dust and see how that goes.
Yeah I have tried that to and nothing so far.
I have gotten the warp down to about a 0.5cm in the middle but this looks shithouse still when you cut it or anything.
I’ll add updates as the come.
Thanks again guys for the help and tips.
I guess it’s helpful to discuss the detail publicly even if we both know it – since other people might find it helpful.
Yes ours heats from the top too. We have been flipping the sheet around in all directions to try and balance out the melting process. Let me know when you figure it all out!
No thank you for your feedback always appreciated.
Yeah I have been using the same stone blocks and squishing the sheet between that,
I have found that as the heat press only heats from the top down. This has something to do with the warping because if I flip the sheet and cool it down in the same stone blocks they come out straighter. I am wanting to add a tin sheet to my mold so it can hold more heat on the bottom as well and see how that goes.
It’s crazy what you can make from a good sheet tho.
Thanks again for your help.
Hey @adzie23, good to see you progressing and working away.
What’s your latest cooling technique? You mentioned a concrete/stone slab, which presumably goes on top. What’s underneath? At risk of patronising you, warping should be less between two materials that will absorb the heat at the same rate (so the same kind of slab top and bottom), slowly and under as much pressure as you can bother to apply. We haven’t been able to get super flat sheets yet, but have recently tried a book binders press – a fairly small cast iron thing – which seemed promising.
just an update on my progress with my heat press,
1. Have been able to constantly make 29.5cm by 25cm by 1cm.
2. Warping aaahhhh! Very close to working this out but frustrating at the moment.
3. I have forgotten most of my woowork skills from school but they are coming back slowly, these are just proof of concept mainly.
Any hints or tips let me know.Thanks.Adz.
Test 1 new mold.
Black and- 550g.
36cm by 26cm by 1cm.
Hello fellow humans,
Here is an update on my progress,
With my first two sheets I made a little table that is quite sturdy and looks really cool. As I did very little to pretty it up.
I then made a cool af looking sheet out of pp and hdpe bottle caps, with a new cooling technique just squishing it between two concrete slabs, about 15kg each.
I just made a mold for my heat press that is easy to fill, flip and pull apart to clean or get stuck plastic out. It’s just aluminium cut to fit my silicon sheets with a threaded bar through it held together with butterfly nuts. This seems to work so far. This makes a 34cm by 26cm sheet.
My first test in this I used 550g of abs plastic.
200c for 20min each side. Then cooled down between slabs of concrete. It’s super smooth and not as shinny as the other test but still nice to touch. Quite strong but could of gone hotter.
I am going to try and make other things with these sheets, if you guys have any ideas that you think might be easy to make please let me know.
I am looking for things around offices and schools as I work in a uni.
I need to look into different ways to join plastics as well but so far very happy with my progress.
Thanks everyone and keep being cool.
Nice work – pretty thick!
I forgot to mention that we flip and rotate the sheet during the press so that it gets a nice even melt on all sides. Although the rougher surface could be a design feature in some applications 🙂
Thank you so much for sharing your insight and tips with this, I haven’t had the time to test it the way I want to yet but will this coming weekend, so I’m very happy to gather notes beforehand.
I will try to make some kind of squishy machine for the sheets in time but for now I will try that tin sheet idea.
I have found that it doesn’t seem to take too long once it is heated up to start to melt. I would love to try molds in this as well.
I will keep this page updated once I get to it.
Thanks again guys.
Thanks guys for the tips,
I checked these guys out that’s amazing what they are doing.
Thanks mate I will give it a try, I’m just trying to make a 1cm thick sheet anywhere from 20cm2 to 35cm2. Hopefully after a little r&d I’ll have this.
As for the machine it’s amazing, I think once I have worked out the mold this will be able to start a small production for sheets.
Once I have some update I’ll let you guys know.
Keep up the good work guys.
I think ‘plastacs’ has the same machine and posts from time to time something on instagram.
Looks like this machine could get some upgrades, judging at the surface finish of plastics coming out. I’d weld some extra metal on each corner to enable fast tightening bolts (no idea how its called in english) but possibly the entire structure isn’t made for more pressure.
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