There are three basic methods to remove the air from a bag:
Chamber – On a chamber machine, the vacuum bag is placed into a chamber within the machine and then the machine withdraws all of the air from the the vacuum chamber. The air inside the bag is withdrawn at the same time since the bag is completely within the chamber. Thus, the air withdrawal from the the bag is indirect.
Suction – On a suction machine, the vacuum bag remains outside of the machine, but held into place by a clamp. The bags will have a small raised pattern. This raised pattern prevents the bag from closing completely and allows the machine to vacuum the air out. This method relies on the machine directly withdrawing air from the bag. This is the most common type of vacuum sealer machine.
Handheld – A handheld works somewhat like a suction machine. However, instead of a clamp, the bags themselves have a special designed opening that attaches to the handheld machine. While attached, the attachment point is open and when the handheld is unattached, the opening becomes closed.
This can be very confusing because different manufacturers, retailers, and review sites use the automatic and manual terms slightly differently. The reason is due to the number of steps that a user has to initiate. There are many steps in the process, including
- Properly positioning the bag for the machine to perform vacuuming and sealing
- Starting the vacuum process
- Stopping the vacuum process
- Starting the sealing process
- Stopping the sealing process
- Releasing the bag from the machine
On some machines, you might have the ability to control, or intervene, in all steps. On most machines, the user will have to start the vacuum process, but the machine can complete the remaining tasks without additional intervention, except, maybe, releasing the bag from the machine.
However, on other machines, once the machine senses that a bag is in place, it will begin the process and go all the way through the remaining steps. These machines are fully automatic.
On the other machines, since the user has to start the vacuuming process, then starting is a manual process and, hence, these are manual machines. However, some retailers or manufacturers might call these machines automatics (distinguished from fully automatics). They distinguish these machines from manual machines if the user has to start the sealing process separately from starting the vacuuming process. That is where the confusion often occurs.
For Compare Vacuum Sealers, we define them as
Automatic – The bag is placed into the opening / clamp, which the machine senses, vacuums the air, and seals the bag without any further intervention by the user.
Manual – After placing the bag into the opening / clamp, the user has to take some other action to have the machine, vacuum the air and/or seal the bag.
Although it may seem counter-intuitive, most users probably want a manual machine. This allows you to start the process when you are ready and, in some machines, intervene in the process as necessary. Several machines have features that are manual as well as automatic (but not fully automatic). See the manufacturers full process description to ensure that you are getting the process you want.