I said:

Chip:

My name is ****** and I am a senior Chemical Engineering student at
the University of ******. For a project I'm designing a tank for
solid-state fermentation that I will need to pressure cook at 15 psi for
30 minutes and I'm considering using the Camwear 18 qt. round storage
container as the starting point for this tank.

For reference, a pressure cooker loaded with distilled water and running
at 15 psi reaches a maximum temperature of 120 C. From the polycarbonate
Wiki page, PC has a melting point of 267 C, glass transition temperature
of 150 C, compressive strength of >80 MPa and an "upper working
temperature" range of 115-130 C. This last value is the only concern I
have at the moment.

Cambro reports the upper limit of the temperature range for this product
to be 99 C. I was wondering if this was to cover company liability
in case people try to cook with it on a stove top or something along
those lines. But in the event that 99 C is the actual upper limit, I am
concerned about the product deforming after a short session in the pressure
cooker. I was wondering if you had any guidance for me on this because I
have not found any other alternatives that even come close to being in
two digits. Over the entire course of this project I cannot see
myself pressure cooking the unit more than twenty or thirty times.

Thank you for your time,

******
University of ****** Chemical Engineering
Mycotoxicology Studies

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Cambro Senior Engineer Chip Jarvis said:

Hi ****

I do not recommend PC for this application. The melting point you
reference is really the molding temperature; polymeric melting
Temperatures are a bit of a tricky subject. PC might withstand
a single run at 120 C but I would expect it to experience significant
plastic deformation, especially with successive runs.  If you want to
use plastic, try to find something in Ultem material. I know that my
suppliers at Thermo Scientific stock similarly shaped containers in
Ultem. Especially if you plan to attach anything to your tank, do not
use PC, because even slightly deforming you will lose alignment and
break seals.


Best Regards

Chip

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