Why does air enter the bag?

Why does air enter the bag?

Why does air enter the bag?


Why air enters the bag that has been closed to the void

Occasionally it will have happened to you or it will happen to you that you empty a bag and after a few hours or a few days you will see how it is again full of air.


This can be for several reasons but there are two that occur in 99% of cases.


1 - That the bag has a manufacturing defect and enters air through a joint or even through it. In the market there are bags of all qualities and some are really bad. It is not our case since the bags that we have are of first quality and therefore this cause (in our bags) although possible it would be very rare.

2 - There is a defect in the seal (most likely). There are several reasons in turn for a bag has been poorly sealed.


Let's go from the most usual to the least usual:



  • The sealing bar is dirty, there are traces of food or grease and therefore the sealing has not been uniform even we can see after a few hours as you can take off the seal easily if not all in some areas. You have to clean the sealing bar on both the top and the bottom with a cloth and a little glass cleaner.


  • The sealing bar is clean but with the naked eye in the bag it can be seen how, when introducing the product to be packaged, the interior of the bag was stained in the sealing area. Any small food or fat remnants can leave a bubble in the seal. The outside pressure of the air is so strong that it will end in a few hours or days by entering air through that bubble. The best remedy, when we go to pack sausages, meats or any product that stains, is to make a hem in the bag before putting it as we do with the bottom of a pair of pants. We take the mouth of the bags and bend it outwards so that there is a 5 or 6 centimeter hem. We put the product inside, we clean our hands and undo the hem. We will get a perfect seal.


  • When the vacuum is made in a bag containing meat (with some blood), fish, etc. a little liquid has risen, although it has not left the machine if it has reached the sealing zone and air has entered very quickly. When packaging products that release some liquid, after putting the product in the bag put a piece of kitchen paper crossed so that it is between the product to be stored and the area where it is going to make the seal. When the machine sucks the air, the liquid will tend to rise towards the sealing but it will remain impregnating the kitchen paper without reaching the seal. The seal will be perfect and no air will enter the bag


  • In the bag you can see well sealed areas and others as more burned where the air has entered. Probably the Teflon that prevents the contact of the electrical resistance with the bag is very used or damaged. In this case it will have to be changed.


Remember that hygiene will mark the life of your machine. If there is no proper hygiene, the locks will deteriorate very quickly and the machine will work worse and worse. If they are going to stop liquids to the vacuum pump (especially if they contain sugars) it will deteriorate very quickly and the life of your machine will be very short.