How to detect leaks on vaccum bag ? i have a analog vacuometer , i do proves and always lost pressure , i close the vaccum line , for check trap pot , and lost pressure, always lost pressure , im going crazy ,  i need a perfect  vaccumnbag for infusion please help me

There's no real tricks to it unfortunately, you can spend hours looking for leaks. Sometimes it's just easier to start again, pull the bag off and rebag it being very careful to keep everything very clean so you don't have any stray fibres getting under the sealant tape and being very gentle to avoid putting tiny punctures in the bag.

As Hanaldo said, there's no simple answer and it'll just be a matter of getting your bagging technique to a level where it's reliable and consistent

Make certain that your mould perimeter is clean and it might help to go around the area where your tape will go with a cloth and some solvent cleaner, to ensure that the release agent isn't affecting the tape, whilst ensuring that any stray fibres are cleaned away. Also, make sure that your pleats are big enough to reduce strain on the tape when vacuum is applied. An overstretched bag will be prone to leaking so make the bag much too big rather than too small. 

Most of the time, leaks will occur around your pleats, so go around the whole of the taped area after you've applied vacuum and press everything down firmly, paying attention to the base of the pleats, in particular. You might also find that a 'doughnut' of tape around the top of each silicone connector will help reduce any crimping of the bag once you insert your inlet and exit pipes. These too can be a source of leaks if the bag is excessively crimped when the pipes are inserted. Place two finger around the top of the bag/connector to hold things flat when putting the pipe (with an angled cut) through the slit in the bag. 

By no means a standard way of doing things, but doubling-up on the tape and folding it completely back on itself when creating pleats might also help ensure that the length and base of the pleat has enough tape to allow for firm pressing down to, again, ensure that creases (and possible leak sources) are reduced. You'll use a little more tape, but I prefer the additional certainty having a bit more thickness of tape can bring around these areas. 

+x

 

Hanaldo - 1/27/2020 10:06:02 AM

Its also much more forgiving on the thumbs! 😂

As temps are down to single digits here and the tape is a bit firmer to handle, they're still usually throbbing by the time I'm through!