Common Issues with Airfill Heat Seal Balloons

Modified on Fri, 17 Sep 2021 at 05:26 PM

Read the article carefully and if the solutions provided do not resolve your issue– please open a support ticket.

Please Note: Airfill balloons, also known as mini or micro balloons, are meant to be inflated with air, heat-sealed, and attached to a cup and stick.  Most airfills do not have self-sealing valves. The information below relates to balloons without self-sealing valves.


Balloon Loses Air Quickly


A common complaint about airfill balloons is not being able to complete the seal of the balloon. Most times when balloons are returned with this complaint, we test the balloons and always find a seal is possible. A foil balloon is manufactured by simply sealing two pieces of film together, so naturally, a tail can be heat-sealed closed too.


Heat-sealing an airfill balloon is tricky because it requires setting your heat-sealer to the perfect melt temperature required to seal a specific balloon. Not all balloons are manufactured using the same film, some are thicker or thinner than others, so the melt temperature of each film will also be different (See chart below).


Manufacturer Melt Temperatures

Anagram Balloons


CTI Industries






It does take a few tries before finding the correct temperature for the film to seal. We suggest starting at a low temperature and slowly increase it to a higher temperature. There are films that feel quite thick compared to another balloon and a thicker film will require a higher heat setting. If you melt through the tail of the balloon, most likely the balloon is no longer usable. However, if you try to seal the balloon and it does not seal, you can salvage it by inflating it again and sealing it.


Most complaints we receive about balloons not sealing are for a manufacturer called Classic Balloons. They often use thicker films and require a higher heat setting on the sealer. If you do not increase the heat-setting on the sealer, the balloon’s tail will not seal together and the air will escape.


Below you will find information, solutions, and how to do an air bubble test.

IssueThe balloon pops when inflated.

Solutions: If a balloon pops when inflating, this is a manufacturer defect indicating seal around the balloon could not handle the pressure of inflation.

IssueThe tail of the balloon tears.

Solutions: Use another method to inflate the balloons, such as a smaller balloon pump.

IssueMelting through the tail of the balloon.

Solutions: If your heat sealer's setting is set too high it will cause the tail to melt. To adjust the heat setting, look for a control knob on the end of the heat sealer and turn it lower.   

IssueI tie the balloon and they leak.

Solutions: Airfill balloons are meant to be heat-sealed. Tying the balloon will not hold the air inside very well.

IssueThe balloon loses air quickly after heat sealing.

Solutions: Indicates the heat sealer temperature is too low to create a proper seal.  

  • The heat-sealers temperature might be too low to create a proper seal.  
  • Are you lifting the sealer before the seal is complete? Are you not pushing down on the sealer and initiating the seal? It is important to push down on the sealer long enough for a proper seal to be formed.
  • Could the element be damaged? Check if the heat sealer's element is bent, broken, or discolored.  Elements sometimes need replacing.
  • Try sealing the balloon in multiple places. We suggest sealing a balloon twice.
  • If you are blowing up a balloon with your mouth– please note the hot air contracts inside the balloon once cooled. Only use an air pump to inflate the balloons.
  • Check where the air is leaking by using a Water Air Bubble Test.  See instructions below.   


The Water Air Bubble Test

If you are having issues with a specific balloon design you should test the balloon to see where the air is escaping from. 

  1. Fill a container with tap water.
  2. Submerge the balloon underwater.
  3. Gently press down on the balloon.  
  4. When you press on the balloon, you should see bubbles where the air is escaping from. 
    • If bubbles come from the seal of the balloon, then the seal is not complete and you need to turn up your heat sealer's temperature higher.
    • If the bubbles come from somewhere else, (i.e. around the balloon) then the issue is with the manufacturing of the balloon and not the seal.

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