Shipping inflatable objects

Susan L. Maltby <susan.maltby<-at->utoronto<.>ca> on behalf of Amber E.
Morgan,  writes

>    We have a number of inflatable toys from the 70s and 80s that
>    someone wants to borrow from us.  The toys came from Warhol's
>    do not alter items we find in the Time Capsules, opting to leave
>    them exactly as Warhol left them.  In theory, these should be
>    really easy to ship--they aren't fragile and they act as their
>    own padding.  Except we have to ship them internationally on a
>    cargo flight.  I've seen what happens to bags of chips and
>    plastic bottles at altitude so I'm pretty worried about these
>    toys.
>
>    The obvious answer is to deflate them, but our curator does not
>    want to do that. ...

Based on my own experience with bags of pretzels, chips, orange
juice, and other sealed containers at 39,000 feet, there may not be
enough expansion to worry about.  If the toys were partially
inflated, one could use Boyle's Law to calculate the expected
expansion.  However, if the toys are to be shipped fully inflated,
or if your estimate of gas expansion indicates too much inflation,
then Barry Knight's solution is brilliant.  The rub here is that
most shipping fees (especially shipping by air) are priced on
shipment volume, as well as weight.  Also, building a rigid and
air-tight container from scratch can be quite challenging (as any
showcase manufacturer).  Providing an appropriately sized rigid
air-tight box could prove to be a challenge.

So it got me thinking: there's no reason the external box/container
needs to be rigid--only non-stretching under tension (ie, not a
rubber balloon).  Such a thin-walled plastic package will first
expand as the external pressure is lowered, and will eventually
become rigid itself when the pressure differential is great enough.
Once the bag is fully inflated, decreases in ambient pressure should
have no effect on the pressure inside.  (Presuming there are no
pinholes, and the bag is strong enough and does not burst.)

Escal and other barrier films are strong enough to make a tightly
fitting bag that will limit the expansion of any inflatable toys
stored inside.  As a bonus, one could add some oxygen scavenger
and/or PROSorb to the package to control the environment whilst in
transit.

Jerry Shiner
Keepsafe Microclimate Systems


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                  Conservation DistList Instance 30:8
                   Distributed: Sunday, July 10, 2016
                        Message Id: cdl-30-8-007
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