Many food products as well as other types of products also make use of M.A.P. or Modified Atmosphere Packaging. M.A.P. uses vacuum to remove the natural air from the package and replaces it with a gas or gas mixture depending on the product being packaged. The most common gas used is nitrogen. In almost all cases the gas used is an inert gas or gas mixture. In a limited number of applications the gas may not be inert but in that case the M.A.P. machinery used must be specifically modified to work safely with non-inert gases.
Examples of the benefits of vacuum and M.A.P. packaging of non-food products includes the dry packing of electronic products such as trays of silicon chips, wafer boats as well as completed circuit boards. Many medical and pharmaceutical products also benefit from vacuum and M.A.P. packaging. You will also find vacuum packaging used in conjunction with compression to remove the air from products like dog beds, fabrics and even bean bag chairs to allow more product to fit in a smaller size package in order to reduce shipping and storage costs.
All vacuum and M.A.P. packaging must be accomplished using vacuum packaging machines and these machines are of two basic types, vacuum chamber packaging machines and nozzle or snorkel type vacuum packaging machines. Both types of machines can also incorporate gas flush options with either single stage or multi-stage vacuum /gas flush or in some cases gas / vacuum sequence. Both types of machines have their strong points and their weak points.
Chamber vacuum packaging machines can achieve higher vacuum pressure levels than nozzle type machines and this means there will be less residual oxygen remaining in the sealed package. This is very important for many fresh food products like fresh red meat, poultry and pork as well as many varieties of cheese products. Another plus for chamber vacuum packaging machines is that they produce very consistent results from one package to the next due to the fact that the same vacuum cavity every time. On the other hand nozzle type machines remove the air directly from the flexible pouch used for packaging the product and this can lead to the vacuum nozzle becoming blocked because the pouch has been drawn over the nozzle before the pouch was completely evacuated. The fact that the vacuum chamber packaging machine evacuates a set size vacuum cavity can also be a minus for this type of machine as the entire product and pouch need to be fully enclosed within the vacuum cavity in order for the evacuation process to be accomplished. This means if your product is large or very large then the vacuum cavity must be large or very large and this translates into a very expensive machine. Vacuum chamber packaging machines are also not the machine to choose if you want what is referred to as a “pillow pack” end result. The reason for this is that in a chamber unit the lid covering the vacuum cavity is held down by the vacuum pressure and in order to create a pillow pack the pressure inside the chamber would need to exceed that of the air outside the chamber and this would cause the lid to open and then all the vacuum would be lost. For the vacuum packaging of delicate products, such as a muffin or cookies the fact that the vacuum cavity is being evacuated means that the inside and the outside of the pouch is being evacuated at the same time instead of just the inside of the pouch as is the case with a nozzle type machine and this means that a complete vacuum can be drawn on the product then gas introduced to bring the pressure inside the package back to being very close to that of the outside atmosphere thus the muffin will not become compressed into a ball of dough or the cookies broken into pieces. This is a major benefit if your product needs very little residual oxygen but cannot be compressed as a nozzle type unit must compress the package in order to achieve the best vacuum possible.
Nozzle type vacuum packaging machines do not require a vacuum cavity are and instead draw the air out of the package directly using either a fixed nozzle system or a retractable nozzle system. This allows this type of machine draw the vacuum faster in most cases as well as vacuum package much larger packages with machines that can be much less expensive depending on the options chosen. An example of this is a product that I worked with several years ago. The product was strips of rare woods that were used by master cabinet makers on custom made furniture and they benefited by being vacuum packaged for storage. These strips were 10 feet long and about 1 to 4 inches wide. In order to vacuum package them in a chamber type machine would have required a custom built unit that could handle the 10 foot length and would have cost well over $ 10,000.00. However since maximum vacuum pressure was not required and the volume was low a lower cost (about $ 2,000.00) retractable nozzle type machine was the perfect fit. Another product that was a perfect fit for a nozzle type machine was special gourmet marshmallow product as it needed to retain positive pressure (pillow pack) inside the package so the product would not be damaged during shipment. This made the nozzle type machine the only practical choice for this application.
The conclusion is that both types of machines have a place in the vacuum and M.A.P. packaging industry and Promarksvac Corporation manufactures a wide variety of both types of machines from small table top vacuum chamber sealers and table top nozzle models to very large (up to 300” seal) nozzle type machine both vertical and horizontal models as well as larger single and double swing lid vacuum chamber sealers. They also manufacture both conveyor fed chambers and fully automatic roll stock machines.