Vacuum Packaging refers to the process of removing the air from a bag, in order to preserve a material/product. The main goal of Vacuum Packaging is to increase a product’s shelf life. The most efficient way to Vacuum Package any product is by using an industrial vacuum sealer. During a normal vacuum cycle, a Vacuum Sealer will use an integrated pump to remove a high percentage of the air contained inside a bag.

In order to increase the shelf life, the important thing is to reduce the oxygen levels to at least 0.05% inside the bag. Air is composed of 78.03% Nitrogen and 20.95% Oxygen (with the other 1.02% composed of Argon and Carbon Dioxide). Nitrogen is an inert gas that will not affect any food or pharmaceutical products.

The biggest problem is the Oxygen inside the bag. Oxygen will increase the growth of bacteria, fungi and the oxidative effect on lipids. Oxygen will allow the products to age and will decrease the shelf life significantly. By using an Industrial Vacuum Sealer, the oxygen levels can be decreased to the necessary 0.05%, increasing the shelf life by at least 30% in most food products.

Not every Industrial Vacuum Sealer applies to every application. There are different models and types of Vacuum Sealers available, and each one of those sealers has different features that can affect the way a production line works. For example, a Chamber Sealer will take a longer amount of time to Vacuum Package a product than a Nozzle Sealer will, but a Chamber Sealer will work much more efficiently with a liquid or a powder.

Nozzle Sealer vs. Chamber Sealer

Both the Nozzle Sealer and Chamber Sealer will be able to Vacuum Seal a package with a solid product and have the same results, but each machine type will offer a number of unique number of benefits to a production line. A detailed description of each individual machine type follows.

Nozzle Sealer

Also known as a snorkel sealer,  this type of machine will provide you with a faster vacuum cycle and a higher amount of control over the bag. All Nozzle Vacuum Sealers are foot pedal operated and allow the user to hold the bag in place during a Vacuuming Cycle. Most nozzle sealers use an integrated Venturi Vacuum Pump that has no moving parts and does not need any regular maintenance. This machine is widely used in the packaging of coffee beans and solid food products.

In a Nozzle Vacuum Sealer, the pneumatic cylinders that open the jaws, the cylinder that moves the nozzle and the vacuum pump require a continuous supply of dry compressed air to work. Essentially these machines require an air compressor that can achieve a pressure of 120 psi and provide a continuous supply of at least 7 CFM of dry compressed air to work. The use of compressed air and the Venturi Vacuum Pump allows the Nozzle type units to be faster than the Chamber type units.

Nozzle sealers are foot pedal operated and the majority of them use a Programmable Logic Controller (PLC). The PLC allows for the machine to be password protected, and for different “recipes” (settings) to be saved on the machine, in case the user has different bags to Vacuum Package.  The PLC also makes it much easier to program the machine by using a digital display.

A Nozzle Sealer Vacuuming Cycle would have the following steps: The pneumatic cylinders in the machine will open the jaws of the machine and the Nozzle will come forward. At this point the user will introduce the Nozzle inside the Bag, and place the bag over the bottom jaw of the machine. Once the bag is in place, the user will then begin a cycle by pressing the Foot Pedal Switch.

At that point the pneumatic cylinders will bring the jaws down and the Nozzle Sealer will begin vacuuming the bag. Once the vacuuming has been complete, either by time or pressure, the Nozzle will retract, and the bag will be sealed in place. After sealing has occurred there will a Dwell/Cool time, so that the seal can set on the bag. The pneumatic cylinders will then open the jaws releasing the bag. The cycle will then be completed.

The Cycle described above would be completed in approximately 10 seconds, using a 10” x 16” Mylar laminated bag with rice. If Gas Flushing was included into the cycle, it would add an extra 3 to 4 seconds in time to the Cycle. With that in mind we can calculate an approximate estimate of the amount of bags that can be Vacuum Packaged in an hour. With a basic Nozzle type sealer, it is possible to vacuum package at least 200 bags within an hour (Ex: 10” X 16” bag). 

While vacuuming with a Nozzle Sealer one the biggest benefits the user will find is the amount of control they have on where the bag will be sealed and how evenly the product will be distributed inside the bag. By using a Foot Pedal Switch, the users have their hands free to hold the bag and vacuum it for as much as they want to.

Some of the other benefits of the Nozzle sealers include:

-Ease of access to controls in the machine (most Industrial Grade Nozzle Sealers have an easy to use Programmable Logic Controller)

-The ability to use the machine as just a sealer (In case the user want to cut and seal custom sized bags), 

-To Vacuum and Seal any size of bag even if the jaws are smaller than the bag (the user would seal a portion of the bag and the Vacuum seal the rest).

Some of the disadvantages of the Nozzle sealers include:

-Only possible to vacuum and seal one bag per cycle unless you have multiple nozzles

-Operators will typically be required to hold the product and manually adjust pouches every cycle

-Will normally require a separate compressed air source connected to the machine at all times

-Powders and ground products are detrimental to the operation of the machine and will get trapped in the air hose assemblies

-If your product fits very close to the top of the bag the nozzle may come in contact or damage it

Chamber Sealer

This type of sealer is capable of vacuuming a higher percentage of oxygen from a bag at a much slower pace. A Chamber Sealer is capable of removing enough oxygen to lower the Oxygen level to 0.02%. Chamber Sealers should always be used with extremely oxygen sensitive products.

Chamber Sealers are not foot pedal operated, instead they have sensors that activate once the lid of the machine is closed. These sealers use an internal Vacuuming method, the user has to place the entire bag on the inside of the Sealer.

The Chamber type sealers have an integrated oil pump that removes all of the air inside the chamber and the bag at the same time. This is an oil pump that does not require a source of compressed air. The biggest difference between a Chamber Sealer and a Nozzle Sealer is the way the vacuum pressure is applied to the bag. In a Nozzle Sealer the change in pressure occurs on the inside of the bag. In a Chamber Sealer the change in pressure occurs on the inside of the chamber, which means the pressure changes on the inside and outside of the bag at the same time.

A Vacuuming Cycle on a Chamber Sealer would have the following steps: A hydraulic arm will open the lid on the chamber sealer. At this point the user would place the bag on the inside of the chamber, with the open part of the bag on top of the sealing bar. The user will then proceed to close the lid of the sealer, and the Vacuuming Cycle will begin. The Vacuum Pump will activate and will evacuate all the air inside the chamber and the bag at the same time.

The amount of air removed will depend on the setting specified by the user, either by time or pressure. Once the specified vacuum time/pressure is achieved the sealer will either Gas flush the bag or seal it (This will depend on the way the machine is programmed by the user). Most Industrial Chamber Sealer with seal the bag twice to insure the seal is strong enough to hold the vacuum. After the bag has been sealed, there will be a Dwell/Cool time, so that the seal sets in place. Once the Cycle has been completed the sealer will then pump air into the chamber, bringing the pressure back to normal inside the chamber and opening the lid. 

The Cycle described above would be completed in approximately 20 seconds, using a 10” x 10” Mylar laminated bag with rice, with a machine that has a 14” x 14” Chamber. If Gas Flushing was included into the cycle, it would add an extra 5 seconds in time to the Cycle. We can then estimate that this machine will be able to Vacuum Package approximately 160 bags per Hour (Ex: 10” X 10”).

Some of the benefits of the Chamber sealers include:

-Greater vacuum percentage (lower oxygen) as compared to a nozzle type sealer

-A larger seal bar (or more than one) will allow the operator to vacuum and seal multiple pouches at the same time resulting in greater productivity

-Little to no operator involvement after the lid has been closed and the cycle has started

-Options for percentage vacuum will allow for partial vacuum if making an object immobile is your goal

-The compressor is built-in so all you need is an electrical outlet

Some of the disadvantages of the Chamber sealers include:

-More expensive than a conventional nozzle type sealer

-Head to head with the nozzle type the chamber is slower

-Heavier and more difficult to move should you have multiple production areas

What to consider before purchasing a machine:

-How many pouches will you be sealing per shift?

-How large is each pouch?

-What is the pouch made from?

-How much space do you have available for another machine?

-Will this be a tabletop application or a free-standing unit with a footprint?

-Do you plan on ramping up production in the very near future?

-What is your budget at this time for this piece of capital equipment?

-What is the product you are packaging? 

Options to consider:

•Gas flush:  Used to introduce an inert gas in order to preserve products and minimize the amount of oxygen ingress through the film.

•Typical applications may include:  potato chips or snacks that are particularly susceptible to oxygen or water vapor

•Soft Air:  Fills the chamber with air at a much slower rate to prevent wrinkling of the product

•Higher voltage:  May be required for your facility

•Cut off seal wire:  if you are using one size pouch for multiple pouches this may help remove excess material after vacuum and seal cycle

•Multiple nozzles:  Results in increased productivity when used in conjunction with an adjustable shelf

•Bi-Active Seal:  Necessary when sealing MylarFoil or unusually thick pieces of material together