Team K.a.L.M.

[Eventorizon]

Get a small piece and hit it with a hammer. If it deforms without breaking, it will be near HDPE, if it shatters its closer to LDPE and if it in between it may have some PET in it too... note: this is all coming from a handout I got in Materials for Designers at uni so its pretty vague :-P

[Ellis]

Would be surprised if LDPE is the more shatter prone. Why would lower density be more brittle, surely it'd be even softer and more malleable than a high density variant?

[overkill]

I find that stiffness & brittleness increases as the density goes down. UHMW-PE is softer than HDPE, which is softer than LDPE; sometimes there is very little difference between them. Manufacturers often have variations within each type IE I have some UMHW with a higher melting point and another which has more wear resistance.

EDIT: I found this interesting comparison article: http://en.wikipedia.org/wiki/Polyeth...ene_.28HDPE.29 it makes linear LDPE sound particularly interesting.

[Niels - Team K.a.L.M.]

I swung a 4kg hammer at the stuff and it flexes a little but didn't deform.

From what i know, LDPE is easier to break than HDPE.

But yeah, it's more malleable that regular hdpe and therefore screws will get ripped out easier.
It's because I have tons of it that I use it.

[cavecrusher]

Hit it with a hammer.

very scientific :P

Then again, that's how a izod/charpy notch test works...

[Eventorizon]

Would be surprised if LDPE is the more shatter prone. Why would lower density be more brittle, surely it'd be even softer and more malleable than a high density variant?

Those chopping boards you used on Tormenta 1 were LDPE, need I say more? ;-) LDPE has shorter polymer chains and as a result breaks more easily as there are less crosses and linkages. (I hope I remembered that right)

[maddox10]

Simple solution to the ripped out screws. Ranglebox.

[leorcc]

very scientific :P

Then again, that's how a izod/charpy notch test works...

Large Hadron collider, bash 2 atoms together and see what happens.

[cavecrusher]

Large Hadron collider, bash 2 atoms together and see what happens.

3000 X 100 billion atoms, with a total energy of 300 MJ.

That's a very very big hammer...

https://www.youtube.com/watch?v=_NMqPT6oKJ8

[Niels - Team K.a.L.M.]

I'll just wait and see...

[overkill]

Just be careful...

https://youtu.be/jyaLZHiJJnE

[Ellis]

Those chopping boards you used on Tormenta 1 were LDPE, need I say more? ;-) LDPE has shorter polymer chains and as a result breaks more easily as there are less crosses and linkages. (I hope I remembered that right)

I don't think they were LDPE. There seems to be two kinds of off the shelf chopping board, the horribly brittle type (literally like glass) I had and the slightly gummy type. I have cracked the latter in tests also. It's very much like a cracky HDPE.

The glassy stuff I had was inconsistently moulded with holes inside, was semi opaque and was much more like acrylic or polypropylene than any polyethylene I've messed with.

In any case I'm fighting Niels twice so hopefully it is a slightly cracky type.

[Niels - Team K.a.L.M.]

Valkyre 2 gauged it... No cracks... Took the topplate half off as well.

[Niels - Team K.a.L.M.]

I tentively put Glutton on the scales today.
I was worried about it's size and I got a bit of work to do.

It does live up to his name it seems...




It can 'eat' another 4 kg at the moment.
The only things missing while weighing it were the wiring and a toplid.

[Eventorizon]

Just had a thought, the material you are using might be UHMWPE, or Ultra High Molecular Weight Polyethylene. Certainly looks right. Its designed for high abrasion applications and doesn't warp as it has very low moisture absorption. No idea how to test for it though so just an idea.

Any chance of some pics of it on the scales?