How to restrain two plastic sheets in tension

[e709]

I'm working on a military protective structure and need to restrain two sheets of plastic (5mm and shaped) 300mm apart. The void in between will be filled with earth/sand to provide protection against a particular threat. The external side of the plastic sheet cannot have anything protruding to any significant distance and I need to find something that will hold them in position and resist the outward pressure exerted by the fill.

Does anyone have any ideas? Obviously I could use threaded bar with nut and large washe, but this would stick out too far and would mean personnel would snag themselves often.

Hopefully this is clear enough, but if not let me know and I'll try to produce an image.

Cheers.

 

[desertfox]

Hi e709

What about a countersunk rivet head on one side and peen the other end of the rivet into a countersunk recess, obviously you would need some kind of spacer inbetween the sheets.

desertfox

 

[IRstuff]

What is the area you are trying constrain?

If it's relatively small, why not chicken wire?

If it's large, you will need some sort of framework, like a garden trellis, then chicken wire

TTFN

FAQ731-376
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[e709]

Thanks for the quick relies guys.

Desertfox - I'm afraid you lost me, I'm not familiar with terminology you use. I do however understand the need for a spacer.

Irstuff - the sign I'm working on is a protective structure which the end user would erect to protect themselves. I'd really like to achieve an 'ikea' type build in which the builder couldn't get anything wrong and am therefore looking for simple snap fit connector. I'm sure that there's something outer there that does this, but it's just a case of find it. If not we may have to look at get one manufactured.

For now: I'm going to look into plastic rivet manufacturers and see if they can help.

Thanks again.

 

[desertfox]

Something like this is what I mean-

http://www.sapphireproducts.co.uk/275f9.htm

desertfox

 

[Compositepro]

Use similar plastic sheet material bonded or welded between the to face sheets to form vertical baffles or webs. These baffles would lay flat with the face sheets for transport.

 

[MikeHalloran]

I'm thinking paired 4mm holes on 150mm centers, with a 610mm loop of lacing tape through the facing pairs, holding the faces together similar to the way a mattress is tufted. Bond face sheets on three edges, and fill through the fourth. Unfilled, the major faces would be loosely tied to each other, but only a little awkward to handle.





Mike Halloran
Pembroke Pines, FL, USA

 

[KENAT]

Acorn Nuts?

Posting guidelines faq731-376

http://eng-tips.com/market.cfm?

(probably not aimed specifically at you)
What is Engineering anyway: faq1088-1484​

 

[chicopee]

May be a bit late but I have a sketch(see attachment) that may be of some help. It's not my best sketch but you'll figure it out.

 

[Reg87]

Do you have to use sheet plastic? Sounds like your trying to reinvent a small version of the hesco barrier

 

[Richar24]

If you have enough of a budget you can probably have the material extruded with the faces 300MM apart and have the internal ribbing to support the wall section as part of the extrusion. This way you have no fastners of external protrusions.

Hope this helps