Author Topic: Polycarbonate vs Acrylic sheet.  (Read 1616 times)

Polycarbonate vs Acrylic sheet.
« on: 26 February, 2018, 09:43:06 am »
Is polycarbonate sheet, for a given thickness, more flexible than acrylic sheet?

I'm trying to roll a sheet of 2mm into an approx 250mm diameter tube.  The acrylic sheet cracked quite easily, but that could have been the cold temperatures in the garage at the weekend.  I then found a sheet of thinner acrylic that was 'glass' on a giant poster clip frame.  This rolled much more easily but then cracked along the length in many places overnight.

The design I'm following use polycarbonate and it 'looks' quite flexible.  However you can't just go down the road and buy it - it's Amazon or Ebay with £9-10 delivery charge.  The sheet would need to be 800x400 approx.

If you are interested it will be one of these:

https://www.youtube.com/watch?v=c19NzKRkv7E

Rolling the sheet at 5:17.

Thanks

R

Re: Polycarbonate vs Acrylic sheet.
« Reply #1 on: 26 February, 2018, 10:17:33 am »
Hi Russell
I think you're going to struggle to achieve that with polycarbonate or acrylic - did you know that you can buy ready-made cylinders in acrylic? Not cheap however.
I think you may have more luck in forming a cylinder using PET - its the stuff that 2l drinks bottles (amongst other things) are made from.

Re: Polycarbonate vs Acrylic sheet.
« Reply #2 on: 26 February, 2018, 10:40:11 am »
You can bend polycarbonate if you heat it up. Never done it myself but its thermoplastic rather than thermoset. A heatgun would do it I think.
I think you'll find it's a bit more complicated than that.

andytheflyer

  • Andytheex-flyer.....
Re: Polycarbonate vs Acrylic sheet.
« Reply #3 on: 26 February, 2018, 10:56:31 am »
Why not use polyethylene?  It's very flexible and you can buy it in whatever sizes and thicknesses you like.

Such as;  https://www.ebay.co.uk/itm/HDPE-Sheet-NATURAL-BLACK-High-Density-Polyethylene-PEHD-Polythene-mm/401002482629?hash=item5d5d9c4bc5:m:mFhPVqT3s1uImIb7Nl_IvPw

You can't glue it (it's weld joined as a rule) but with a bit of molishing you may be able to achieve what you need. It certainly will not fracture in bending.  I used to specify hectares of this stuff for landfill liners and caps.

Re: Polycarbonate vs Acrylic sheet.
« Reply #4 on: 26 February, 2018, 11:11:46 am »
You need a former (something to drap it over, a barrel would do, or you could make something from cardboard) and heat it with something like a paint stripper, playing the heat from a distance - very very carefully, if you get too close, it will burn or get little heat bubbles. I've not done it with anything large, but have bent and twisted 6mm thick acrylic that way. I'm sure there will be youtube vids
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Re: Polycarbonate vs Acrylic sheet.
« Reply #5 on: 26 February, 2018, 11:45:55 am »
Heat is the key. I've successfully bent perspex on a 10mm radius by heating it first.

Re: Polycarbonate vs Acrylic sheet.
« Reply #6 on: 26 February, 2018, 02:00:03 pm »
Thanks all.  Interesting comment from RR - I did wonder how it would be shipped.

Not sure about polyethylene as it would need to be sealed with silicone type sealant and it way more cool to have it transparent so you can see the debris flying around.

Andy's link however, is a supplier that looks to be cheaper overall than others for polycarbonate, that makes it not much more expensive that acrylic, and RR's comment gives me confidence that it would work.

andytheflyer

  • Andytheex-flyer.....
Re: Polycarbonate vs Acrylic sheet.
« Reply #7 on: 26 February, 2018, 11:02:34 pm »
Thanks all.  Interesting comment from RR - I did wonder how it would be shipped.

Not sure about polyethylene as it would need to be sealed with silicone type sealant and it way more cool to have it transparent so you can see the debris flying around.

FWIW, PE is translucent (it's the same material as milk bottles now are, it's only black when they add carbon black to it (or any other colorant)).  And it's only black to aid UV resistance (and the susceptibility of PE to UV is still a matter of debate).

Not sure why you'd need the silicone sealant, high density PE is fairly stiff and would fit nicely into a machined groove in a wooden end plate. If it was me, and having watched the video, I'd make the cyclone of PE, it would certainly work.