We are potentially undertaking a project to build a machine specifically designed to extrude an 80mmx20mm plank (roughly, this could change).
This will require a big ol barrel, a big ol screw, and a big ol motor. Does anyone have any advice or access to resources to work these variables out? We are thinking of using a variable speed inverter with a 2.2kw motor to control pressure but working out barrel and screw size for this is something we need more info on (so far im thinking 100mm inside diameter would do it)
If anyone has any information that would help towards this let us know! if it ends up happening we will start a thread to show the development of the thing
@javierrivera, I’ve a question! I’ve understood -almost- all you’ve mentioned; if you have a nozzle of 50mm diameter it would be -mathematically- enough to fulfill the area he needs to have because of the final size of the ‘product’, but: Is there a possibility to vary the speed and, because of that, get the some output but with a smaller nozzle? Please let me show to you my idea with an example:
Option 1:
– Speed: 1
– Nozzle: 50mm diameter
– Output: perfectly covering the area needed (output of 1960 mm^2, needed: 1660 mm^2)
Option 2:
– Speed: 0.5
– Nozzle: 25mm diameter
– Output: the same as above
Sorry for my english, I hope you can undestand which is my question: Is it possible to ‘play’ with the speed in order to have the same result?
try it @caymans, I don’t know Maybe @suzanne who’s actually build it and extrude beams…
with what you’re saying I imagine that the plastic may fill the bottom part of the die, solidify, and then more plastic would fill the top side… you may create those interesting textures from the video
I see what your saying. However I think it might be hard to have the plastic taper back outwards to the die. Would probably end up being safer to work on the basis of everything tapering inwards and keeping the diameter no less than 80.
I need to get some prices on screws and barrels really, see what we are looking at and wether it will matter to try reduce where possible or if we just go for it with a hefty one.
Mm maybe not really that big, 50 mm may be enough, theoretically:
(Again, not talking from experience, this is how I think it works) You want a section of 80 x 20 mm square, that’s 1600 mm^2 so you’d want a similar area for your circular nozzle. 50 mm diameter is 25 mm radius and the area would be πr^2, 1960 mm^2
That should be just enough, but it will all be down to experiment.
If the nozzle area is bigger than your die, you’ll be pressuring the plastic to pass through a smaller gap, and creating some pressure, which may give you the texture dave shows in the beams video, which looks like lava flowing and stretching. This may be what you want
On the other hand if your nozzle area is smaller than your die, then the plastic fills the die only partially and if the die is not very deep you might end up with a plank like 70 x 15 mm
Thanks for the help so far guys. Yeah the method we are thinking is by pushing through a smaller dye and then running that line through a cooling box with circulated water pumped through. I think power shouldn’t be an issue as we will probably put a 2kw geared motor on it anyway hooked up to an variable speed inverter to control the pressure and speed, that way we have a lot of control on the motor.
My worry is getting the info on the screw and barrel size as once you’ve invested in this theres no going back really. If the plank is 80mm wide (or something near that) I would need a barrel size with inside diameter of 100mm or more? How much more? thats what I’m worried about. Working out that pressure is where we are finding it hard to get info.
I don’t speak from experience cause I haven’t tried this yet, but I think extruding a beam inside a whole length of steel puts a lot of pressure in the motor which is not necessary.
If you have a look at how it’s done at an industrial scale, the tool, the mould with the shape that you want to get, it’s only a few centimeters long, and then you let the beam cool with air or water, using rollers if needed to keep it straight. See here: https://www.youtube.com/watch?v=smXycgOT8ok
But let it fill an entire few meters of steel tube must put a lot of stress in the system, is basically like a few meters long injection moulding !
Nice! Great you are working on that! We use a motor with 0,55kw and in between 5 a 20 rpm, depending on the size of the plug. Normally we use a 1″ plug and 14 rpm. Also, we use a normal screw. We tried planks, but never managed to get one done successfully. We think it’s because it doesn’t evenly spread like a square beam. If you need further help, you can contact us on FB: Precious Plastic Den Haag or tag me on the next message.
Maybe 