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HDPE for neutron moderators.

PostPosted: Tue Sep 06, 2011 8:53 pm
by George Dowell
I like HDPE.

I need to learn how to cut the long pieces shorter.

Panasonic makes a circlular blade for plastic with the teeth on backwards. Only saw one once, but they exi$t.

Paid only $2 per pound but shipping was steep ( by truck)

Geo

Re: HDPE for neutron moderators.

PostPosted: Wed Sep 07, 2011 12:58 am
by Joe Jarski
After trying a few different saws I ended up using a circular saw to cut the 6-1/2" diameter UHMW for my B10 tubes. I had to make several cuts around the outside and then finish it off with a sawzall, but it worked out pretty well with a regular coarse tooth carbide blade. You have quite a pile there, so I'm not sure how it would survive when trying to cut that much. That's the best thing that I've found so far for cutting it.

Re: HDPE for neutron moderators.

PostPosted: Wed Sep 07, 2011 1:25 am
by chrismb
HDPE should cut 'fairly easily', it comes in 300 or 500 molecular weights, the lower the easier cut. I buy '500' in 10mm sheet, makes it easy to deal with and you can build up the layers to the thickness you want. The thickest 500 HDPE I've cut was 3cm with a hacksaw (easy enough, a little exercise and sweat), but whether your thicker pieces require different techniques, I can't say. You might also need to practice how to cut it accurately, if that is what you need, as your blade may become clogged and 'guided' the wrong way to what you wanted by a build-up in the cut.

The UHMWPE is, by all reports, a whole different kettle of fish so the comparisons between what is needed may vary considerably. I've never dealt with it myself. Contrary to intuition, it has a slightly lower density than HDPE (less 'H' per cc).

George, do you know what molecular weight you have there, otherwise it's a trial-and-error to see what works best.

Re: HDPE for neutron moderators.

PostPosted: Wed Sep 07, 2011 3:36 am
by George Dowell
No idea on the HDPE specifications, the original scanner is very "national security" coy about everything. Really surprised they released this stuff as well as the BC-704. One panel is equal to a 2" X 60" He3.

Geo

Re: HDPE for neutron moderators.

PostPosted: Wed Sep 07, 2011 5:44 am
by Starfire
Try to find a saw with off-set teeth - teeth sticking out at a angle - makes a wider cut but no binding.

Re: HDPE for neutron moderators.

PostPosted: Wed Sep 07, 2011 10:44 am
by George Dowell
" by Starfire ยป Wed Sep 07, 2011 6:44 am

Try to find a saw with off-set teeth - teeth sticking out at a angle - makes a wider cut but no binding."


Good idea!

Geo