Hello,
in my company we have started packing sunflower seeds using MAP and the problem we have that in some of the packages during storage a vacuum forms. We use a vertical packaging machine and 100% nitrogen gasses. Can someone advise me why is this happening?
Ufuk Ayyıldız reply
posted[quote="Viktorija, post:1, topic:11141"]
vacuum forms
[/quote]
Do you mean they lose gasses?
I guess some of packs can not be sealed hermetically. Do you check seals periodically?
Could you share some photos?
Viktorija reply
postedI mean the packaging shrinks and tightens around the seeds. During packing there is maybe 5% of oxygen left in individual packages. The packages are sealed correctly, because they are tightly bound around the seeds. We check seals each hour. I took the photo out of internet, but imagine them looking like this after some days :sweat_smile: it is strange, because not all packages become like this :(
image|429x469
Ufuk Ayyıldız reply
posted[quote="Viktorija, post:3, topic:11141"]
I mean the packaging shrinks and tightens around the seeds
[/quote]
This means there is no gas in the pack.
1 hour is too late for check, 15-20 minutes is good and of course it depends on your machine speed.
And how do you check seals?
[quote="Viktorija, post:3, topic:11141"]
because not all packages become like this
[/quote]
because all packs do not lose gas but some of them do.
Viktorija reply
postedBut because there forms a vacuum it means that the seals are okay
Ufuk Ayyıldız reply
postedHow do seem your packs which are OK ( MAP, with Gas ) for you?
The photo you shared not a MAP package, it seems a vacuum pack.
Ufuk Ayyıldız reply
posted[quote="Viktorija, post:5, topic:11141"]
here forms a vacuum it means that the seals are okay
[/quote]
No, this is not true. Pack can lose gas in display, box or case ( under pressure ) and it turns a vacuum pack. this does not mean seal is OK.
Viktorija reply
postedYes, the photo is after storage, not during packing. It shows the problem.
Please see this photo, we use nitrogen in this type of packs.
But if the seal would not be okay the vacuum would not hold, no?
image|419x500
Ufuk Ayyıldız reply
posted[quote="Viktorija, post:8, topic:11141"]
But if the seal would not be okay the vacuum would not hold, no?
[/quote]
It can hold for a few weeks maybe more. Because after packaging proccess there is a pressure in the pack so it easily lose the gas. Also if it is under pressure ( in the box ) this will be easier.
But after lose the gas, air can not enter in the pack easily ( becasue pack in and pack out have same pressure ) so vacuum can be hold.
You can check the gas exist or not with water test as you know.
Viktorija reply
postedBut if I open the pack the vacuum disappears. That means that the seal is okay
Ufuk Ayyıldız reply
posted[quote="Viktorija, post:10, topic:11141"]
That means that the seal is okay
[/quote]
No.
Seal is broken but very very small so air can not enter the pack unless you open it.
Viktorija reply
postedOkay, I will try to merge packages in water. Thank you
Viktorija reply
postedI have suggested your theory to our production manager, and he says this cannot be the case, because during packing in our packaging machines the nitrogen is injected into packages via a tube, then after a second they are sealed, and because of that time that the pressure in the atmosphere and the packages becomes the same
Ufuk Ayyıldız reply
postedso your packs are puffy?
they have nitrogen so inside pressure should be bigger then outside and if you put to bags in a box especially pack at the bottom will subjected to pressure and if seal is not pefect it will lose the gas.
The best way to be sure seals are perfect use water.
Viktorija reply
postedThey are a bit puffy, but soft. I just started working here, so I do not know much about the technology. I will surely merge them in water to check. Thank you again :)
Ndukwe O. reply
postedDon't you think it's possible that the seeds are absorbing some of the gas. Check properly, the treatment given to the seeds before packing and also the properties therein that can cause it to absorb the gas.
Ufuk Ayyıldız reply
postedHi @Viktorija Any update :slight_smile:.
Food & Material Scientist reply
postedis the packaging material of this one (curry written plastic material) and your sunflower seeds the same or different (in terms of the thickness, material type etc).
Good to attempt an appropriate 'control' packet and see if this is due to any absorbance or moisture effect related to the seeds itself and not related to your MAP itself.
Viktorija reply
postedHello,
sorry for the late reply. I have been doing tests and there seems to not be any correlation. Moisture of the seeds has no effect. We have tried packing without any MAP, with MAP, putting packages in water. The only thing is that if I put vacuumed packs on a radiator the packages expands and after cooling vacuum forms again so it probably has to do something with gas and temperature (with MAP and with no MAP)
Azamat reply
postedhi you sold your problems
Ufuk Ayyıldız reply
posted@Azamat sorry, what do you mean?
Oya reply
postedReading some of your explanations, I also thought about the temperature. If the you fill at a high temperature and then store the product at a low temperature, vacuum may form. When T drops in a closed system, P also drops hence shrinking packages that appear to be packed under vacuum.
mirsavv reply
postedHi, I hope you are still active this website. Could you please explain what was the root of the issue and how did you solve it?
Ufuk Ayyıldız reply
postedDo you have a similar problem?
mirsavv reply
postedYes, my friend is experiencing the same issue during packaging. The package is being vacuumed form itself after has sealed. However, the problem doesn't occur with every package. We noticed this issue, so I wanted to write about it here.
Ufuk Ayyıldız reply
postedLet's discuss this on a new topic, adding photos can help to understanding of the problem.