Soft tub margarine packaging...

Hello again!

I made another relative post about designing a margarine factory in Food Manufacturing but it was too general (or generally specific :P). I am making progress with this project but I still encounter many problems. One of them is the type of package used in the final product. The basic stages for margarine production are the following:

1. Emulsifing in a mixing/agitating tank (aquatic phase 20% and fatty phase 80%).
2. Precrystallising in votator unit A (with freon 22)
3. Crystallising in votator unit B (with freon 22)
4. Tempering in tube (necessary???)
5. Packaging...

...I have to create a 10 kg package for margarine which is made from partially hydrogenated (about 20%) refined (by ultrafiltration/bleaching/deodorization) pomace oil and then enzymatically interesterified with lipase 1,3...
Basically the product is quite soft... So I thought of packaging it in a plastic bucket since 10 kg wrapping foil wouldn't be so convinient... right?

But how are those buckets made?
What sort of polymers are used for this?
What kind of machines are used?
How are these buckets sanitized?

Thank you in advance!

Hi Sarara,

Interesting topic you have on the IE of vegetable oils. So much so that I have searched some basic info on them via the internet.

Though not a polymer person, but i guess the most economical material is still polyethylene (PE) or in this case, a high density (HDPE) version. Since it is non-toxic and your shortening does not have a lot of flavors, scalping of flavors should not be a big issue.

The process of making pails is most likely blow molding under high temperature (260°C?), though I am unfamiliar with the machines.

As for sanitation, I guess they are quite free from bacteria as there are no food for them to grow. Just make sure there are no extraneous/fecal matters inside the pails before discharge of shortening.

I have seen smaller packages (<5kg?) of shortening and they are sealed in a PE bag within a carton box. Guess that brings the packaging price down even further.

Good luck to your project and I hope there are some polymer guys out there to help you with this post!

Hey Hongyun!!! Thank you very much for answering!
I actually looked more into it and indeed you are right. Soft margarines are usually filled into tubs made from either polypropylene (PP) or polyethylene (PE).

PP is more rigid than PE so PE tubs are more flexible than PP tubs.
So maybe the "body" of the package (..bucket I guess since its for 10 kg) should be from PP and maybe the lid from PE... Hmm.
PE gives a better weight control during manufacture of tubs than PP.
PP in larger quantities is cheaper than PE.
Both have equal properties in permeability of ultraviolet light and air (oxidation).

Well I will keep looking for more info!

Thank you! :D