How to control or check sachet closure quality?

Hi All,

Although I am not new on this site, but these are my first experiences with starting a topic.

I am i need to get an advice regarding the following:  food supplement (vitamins and minerals) production (powdery raw materials, powdery production) starting a new packing form into sachets.

To build the flowchart and related docs will not be a problem, but physically  as I have no experience with this, I do not know how to control or check the sachet closure quality on a different levels:

 - during operation

-  after a period control of closure of retained samples 

thank you for  any kind of professional responses,

kind regards,

Zoltán 

You can use special eqipment for sachet tightness checking like aquarium filled with water using underpressure. Non conform sachets will show air bubles. 

I have seen facilities where air is injected into packages (to create pressure) and then a finger covers the hole and the entire package it put under water to check for leaks.............the pressure allows you to find teeny tiny pin holes you may miss otherwise

Easy and cheap

This was used as an online operational check