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I How to protect liquid filled pods from leaking on a plane

  1. Mar 8, 2017 #1
    I need a little help from anyone capable...

    My company is looking to ship 1000s of the packages around the US, the problem is as follows:

    The packages contains pods in pic related - they have liquid in them, and sometimes during air travel, the difference in pressure causes them to leak. We can send them ground, but the cost is more than triple

    They are only 6oz packages so if we use first class USPS, its very cheap. However we need to address the issue of leaking.

    Is there anyway to protect the pods from being exposed to this - such as using a shrink wrap machine to wrap the box - we have one, and the plastic on it is quite thick. As far as what Ive found, the pressure in cargo is approx 8000ft, or around 10 psi, so there is a difference of 5.

    Will the plastic seal, if air-tight, prevent this, the plastic shouldnt burst because it is thick.... or is there some other way I should consider?
     

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  2. jcsd
  3. Mar 8, 2017 #2

    russ_watters

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    It is difficult to tell the actual storage configuration, but there are three basic ways to avoid rupture:
    1. Make it strong enough to withstand the pressure difference.
    2. Fill it completely so there is no air and therefore no change in volume with a change in pressure.
    3. Leave slack/flexible material for expansion.
     
  4. Mar 9, 2017 #3
    Package orientation is indeterminate when being shipped, which could explain why some leak and others do not.
     
  5. Mar 9, 2017 #4

    sophiecentaur

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    Another alternative would be to pack them in a pressurised box that would maintain the pods at atmospheric pressure at any height.
    Though, personally, I think it would be better if the whole contents were to leak out and be lost. In my opinion, it's horrid stuff. But that's easy for me (a non-smoker) to say.
     
  6. Mar 9, 2017 #5

    anorlunda

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    Even ground shipments sometimes use highways that cross mountain passes higher than 8000'.

    Can you use something inexpensive such as a loose fitting sandwich bag containing one pod? The bag is there only to catch leakage.

    But, I don't think that your customers will be happy until you find a way to prevent the pods from leaking in the first place.
     
  7. Mar 9, 2017 #6

    sophiecentaur

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    They would survive well enough in one of those BDH(?) cylindrical box. They have a screwed lid and a rubber seal and I'd bet they wouldn't leak at cabin pressure although they are basically designed for immersion under water. Most modern holds are at cabin pressure these days (2000m)
    Problem is that I haven't seen a BDH box for a long time. The equivalent must be available under another name.
     
  8. Mar 9, 2017 #7
    Id imagine those boxes exceed the cost that we would want to spend on this. I guess the company decided to just say screw it and send them anyway. We did a test, some leaked, most didnt
     
  9. Mar 9, 2017 #8

    sophiecentaur

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    It strikes me that it's more a matter of quality control in sealing of the pods. Aerosol cans have been working fine for decades under reduced ambient pressure and the company just needs to sort out its design better.
    The BDH type containers are maybe over the top and I appreciate it's all about profit margins. But faulty goods are not popular with customers who very likely would want to be able to fly with what they have bought.
     
  10. Mar 10, 2017 #9
    The pods cant be sealed completely, there needs to be an airway to allow air to flow through the coil and vaporize the liquid. It's not that they are faulty, they are that way by design. They dont seem to all leak either, and we cant be sure why, several of us have flown with them and the pods do not leak, but it seems like on FedEx or USPS planes they sometimes do, with a low failure rate, maybe 5%
     
  11. Mar 10, 2017 #10

    sophiecentaur

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    Perhaps when they fail, the plane hold is unpressurised. 50,000 ft not 2,000ft cabin pressure.
     
  12. Mar 10, 2017 #11

    anorlunda

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    @Joey O , On second thought, there is something very wrong in your description in the OP. Either your packaging is faulty, or your description of the handling is wrong. Hundreds or thousands of products using liquid filled pods are shipped every day without reports of leakage problems. Dishwasher detergent pods shown in the picture are an example. In the USA, many are shipped across the Rocky Mountains where elevations greater than 8000' are normal.

    GTY_deterg_ml_130816_16x9_992.jpg

    I conclude that you are asking the wrong question. Instead of dealing with leakage, you should be investigating what causes the leaks.

    One last thought. You did not say what the liquid is. Could it be something with a coefficient of thermal expansion is unusually high?
     
  13. Mar 12, 2017 #12
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