Naked Science Forum

General Science => General Science => Topic started by: MarkL on 08/10/2008 15:05:26

Title: How does this alternative to a sandbag work?
Post by: MarkL on 08/10/2008 15:05:26

hello it might be a stupid question  [:I]but how that alternative sandbag without sand work  [???]? http://www.stormtec.net/ it's very interesting.

Title: Re: How does this alternative to a sandbag work?
Post by: JnA on 08/10/2008 16:02:09

I've never seen this before but it looks like the polymer works in much the same way as sand does... block the water.


Actually it's probably more effective since the water logged polymer would create a tighter seal than grainy sand.. 


looks like a brilliant product.

Title: Re: How does this alternative to a sandbag work?
Post by: julyeli on 10/01/2009 20:42:40

i agree

Title: Re: How does this alternative to a sandbag work?
Post by: Mazurka on 25/03/2009 13:26:36

The polymer expands when hydrated.  (Which is why the website also suggests using the bags to soak up water in the basement. 
Other uses for crosslinked polyacrimide is for container gardening when it is used to store water to prevent hanging baskets etc from drying out so quickly.

Title: Re: How does this alternative to a sandbag work?
Post by: tangoblue on 28/07/2009 16:42:39

cool product if you ask me. [O8)].... unlike this guy!

Title: Re: How does this alternative to a sandbag work?
Post by: daveshorts on 19/10/2009 09:57:59

The sand bag is filled with a polymer they use in nappies called cross linked Polyacrylamide, which can absorb over 1000 times as much water as its own weight. You might also have seen it used for keeping flowers hydrated. You start off with little crystals which swell to form jelly like lumps.

The cross linked part of the name just means that the polymer chains are occasionally joined together so it is rubbery when wet rather than just slimey.

Title: How does this alternative to a sandbag work?
Post by: Nizzle on 19/10/2009 10:31:54

I still think this topic is nothing more than advertising...

Title: How does this alternative to a sandbag work?
Post by: Karsten on 20/10/2009 02:03:24

Wouldn't sand be advantageous in many way since it could be considered relatively harmless in the environment? It might clog a bunch of things, but is there any data regarding the effects of careless and fast distribution of some polymer by the hundreds of tons? What do you do with the stuff after the flood? How much energy does it take to make it? Is it more efficient than to transport and mine sand? What chemicals are involved in the making of those polymers? What do those chemicals do? How much do those polymers cost if you consider all costs (even those of proper disposal)? Are those polymers heavy enough to withstand the pressure of water when put up in form of a wall?

Sand bags are simple. I like simple.

Title: How does this alternative to a sandbag work?
Post by: Geezer on 20/10/2009 03:04:12

Quote from: Karsten on 20/10/2009 02:03:24

Are those polymers heavy enough to withstand the pressure of water when put up in form of a wall?

I think that's a major problem. Sand bags are extremely heavy and much denser than water whereas these things, when they absorb a lot of water, are going to have almost the same density as water, because, well, they mainly are water!

It will take hardly any pressure to disloge them and I suspect water will simply flood under a dam constructed of these. They should be about as effective at holding back water as a sponge.