[Milsurplus] "Foam In Place" Packing

[Peter Gottlieb]

Where I work we get mag drive pumps that weigh about 75 pounds which are packed 
with foam in place.  The way it seems to be done is liquid foam is placed in the 
bottom of the box with a plastic sheet on top.  The pump is lowered in, perhaps 
with a small winch, in such a way that it is about halfway into the foam.  This 
gives it a couple inches from the bottom of the pump to the bottom of the box. 
Then when the foam sets the winch is removed, another piece of conforming 
plastic is placed over the pump, foam is injected, and the plastic folded over 
the top enclosing the foam.  Then the box is closed.  Once the foam sets the box 
can be shipped.  On opening the box the top piece of now rigid foam can be 
removed and the pump lifted out.  The bottom piece of plastic and foam cannot be 
removed as it is stuck to the cardboard box.

The larger pumps, 250 through 650 pounds which we use are shipped bolted to 
pallets with wood frames around them and screwed to the pallet.  These are 
shipped 2-4 per pallet.  I can't imagine a box would be useful, except possibly 
on a pallet, for the heavier weights anyway.

Peter
kb2vtl


On 12/29/2017 3:48 PM, Jim Whartenby wrote:
> Interesting topic!
> I found this link after a few minutes of using our friend Mr. Google.
> http://www.sealedairprotects.com/NA/EN/products/foam_packaging/instapak-quick_calc.aspx
>
> Seems that 50 pounds is the upper limit of the graph found in the above link. 
>  For rack mounted radios of the R-390A size, the bottom seems to be around 250 
> square inches which is also off of the chart in the above graph.  So this 
> chart isn't all that helpful in answering Dave's question.
>
> The link below is a guide to picking the foam bags for various size cardboard 
> boxes.
> http://www.sealedairprotects.com/NA/EN/Pdf/quick_vol_guide.pdf
> The #100 bag will fill a volume of 23 X 21 X 2 inches which seems to meet the 
> requirements Dave made.
>
> So a 50 pound radio with about 250 square inch base will stress the foam at 
> approximately 0.2 pounds per square inch.  Even the 75 pound R-390A stresses 
> the foam at only 0.3 pounds per square inch.  Neither seems all that bad to me 
> so I found some "foam in a bag" from something I bought recently which is 
> about 15 X 7 X 2 inches and did a simple experiment.
>
> I guess my thumb has about a square inch of surface area.  Putting this block 
> of "foam in a bag" on a bath room scale and pressing down with my thumb showed 
> that the foam did not dent until about 20 pounds registered on the scale. 
>  Even a dent caused by 30 pounds per square inch seems to recover after a few 
> minutes.  So this concern about "foam in the bag" does not seem to be a show 
> stopper.
>
> If you don't have a solid bottom on your radio, perhaps making a cardboard 
> cutout about the size of the box will allow the foam to expand evenly under 
> the radio as the foam sets up.  Other size bags can be used to protect the 
> radio's sides and front and another #100 size bag will protect the top.
>
> As usual, my concern would be which method is cheaper!  Unused "foam in the 
> bag" is easier to store until needed but foam board insulation from Lowe's is 
> just so convenient!
> Jim
>
>
> --------------------------------------------------------------------------------
> *From:* David Stinson <arc5 at ix.netcom.com>
> *To:* milsurplus at mailman.qth.net
> *Sent:* Thursday, December 28, 2017 5:34 AM
> *Subject:* [Milsurplus] "Foam In Place" Packing
>
> This "Foam In Place" packing:
> So let's say I have a 50 lb radio and a box big
> enough for it.  How does this work?  If I put one
> of those packs in the box under the radio, will it
> really lift that 50-lb radio up and leave an
> acceptable layer of material under it? Exactly how
> does this work?
>
> 73 OM DE Dave AB5S
>
>
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