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High Pressure Processing (HPP) is a cold pasteurization technique by which products, already sealed in its final package, are introduced into a vessel and subjected to a high level of isostatic pressure (300–600MPa/43,500-87,000psi) transmitted by water. Please watch- http://www.youtube.com/watch?v=r5Ufqp_Fq6o

I have 2 questions and somehow i am not able to understand below mentioned.

1) how is it possible to pressurize a plastic container bottle(As in the video) without collapsing the container?

2) what happens if we use a plastic polyethylene bag of juice instead of bottle?Will that bag also sustains such a huge pressure?

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  • $\begingroup$ I would be curious to know how pressure pasturizes. Pressure harms people because we have air inside us. Also N2 dissolves under pressure and comes out of solution when the pressure is released. But that may not bother a bacterium living in carbonated water. $\endgroup$
    – mmesser314
    Mar 2, 2015 at 11:14

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It works because the plastic bottles are filled with water and water is almost incompressible. When subjected to high pressure, the volume inside the bottle stays almost the same (there is a small air bubble that will be compressed), thus the bottle is not crushed.

I believe that a plastic bag would work just as well. The hydrostatic pressure is uniform so there would be no force to deform and tear the bag. And the polyethylene itself should withstand the pressure - after all, it is produced at pressures up to 3000 atm.

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You have to know what method are they using, they are using a tehnique called hydrostatic pressure, here is a good article about that. http://www.eolss.net/sample-chapters/c10/e5-10-04-11.pdf

As you can see the pressure is applied uniformly and there are not pressure diferences as you can see from this video. That means that the object is in hydrostatic equilibrium.

However I don't know why the bottle doesn't change his shape in the process. There says that the bottle "recover his shape ". But that doesnt convice me, we can take it as an experimental fact. .

As the plastic polyethylene bag is going to recive pressure is uniformly, it is not going to change his shape, as the article says it is independent of the produc size and geometry

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