How to Vacuum Seal Bags
Vacuum sealing with the right equipment can increase the shelf life of consumable and non-consumable items. Reducing food waste by increasing storage times is attractive for businesses and consumers. Many people have heard of vacuum sealing or the use of an in-home 'food saver.' If unfamiliar with the process, you may be asking how to vacuum seal bags full of food or other items. Below in bold are the steps needed to vacuum seal with explanations and images.
The Right Bags
The answer to the question begins with the type of bag used. It is essential to use an oxygen barrier bag. Bags with an oxygen barrier prevent oxygen and other air molecules from entering or exiting the bag. The different internal molecules create modified atmosphere packaging, meaning the bag's interior is modified in comparison to the outer atmosphere of the container. Oxygen can be removed and will not re-enter once a seal is made.
Regular plastic or poly bags will not work for vacuum sealing. Even a thick six mil plastic bag will have a high oxygen transmittal rate and allow oxygen to enter the package after a completed seal. Home use vacuum sealers come with channeled or textured co-extruded bags. The coextrusion process combines two or more materials. The nylon/poly combination is used with home use vacuum sealing bags. They will produce an oxygen barrier allowing a vacuum to hold during storage. Other coextruded blends have lower oxygen transmittal rates than nylon/poly. Any foil co-extruded materials will have low oxygen transmission rates for premium storage. Barrier bags used for packaging coffee often have a foil lining for an increased oxygen barrier.
Inserting the Bag Into the Sealer
Before inserting the bag into the sealer, it is vital to leave one or two inches of excess material at the top of the bag. The extra room is needed for air removal and sealing. Multiple vacuum sealers are available on the market for sale. Home use vacuum sealers are considered edge sealers. When the lid is open, a liquid reservoir can be seen. To correctly insert a vacuum bag into an edge sealer, the open end of the bag should be in the middle of the liquid catch. This allows for a full vacuum and contents to drain if needed into the catch during the air removal process.
Nozzle sealers have a nozzle placed inside the bag for air removal. When the machine vacuums, the nozzle removes air. When vacuuming bags, it is crucial to keep the bag from impeding the suction of the nozzle. Pull tightly on each side of the bag to be sure a complete air removal is reached. Once the sealing bar is activated, it will hold the bag in place during the seal and cool down.
Chamber vacuum sealers require the bag to be placed within the sealer. The chambers have one or more sides open ends of the bag, or bags can be placed. Once the lid is closed and the machine starts, a vacuum will form within the chamber to remove air from the bag.
After the bag is placed into the sealer, air can be removed. Some sealers will require users to clamp or fully close the lid before the air removal begins. The amount of time needed will be determined by the bag size and the compressor size within the sealer.
Larger barrier bags will take longer to remove air from them entirely. For home use sealers, the process can take over 1 minute. The key factors are the size of the compressor and bag size. Most vacuum sealers have a timer or sensor to stop vacuuming once air removal is complete. After the air removal is complete, the machine must seal the bag.
If using proper bags, the seal is the most important part of vacuum packaging. It closes the bag to keep external elements out. Home use vacuum sealers have narrow sealing wires for a thin seal seam across the top of the bag. The smaller seal width does not work well with thick barrier bags or heavy products. Products with enough weight and movement can bust through a thin vacuum seal.
If using a home use sealer, a 3 to 4 mil channeled/textured bag is recommended. Heavy products should use thicker bags and wider sealing wires found in commercial vacuum sealers. A double seal may be the best option for heavy products to ensure the contents stay within the bag.
Sealing time settings may not be an option depending on the machine used. Many base model home-use sealers do not have seal settings; therefore must be used with an appropriate bag thickness, or a proper closure will not be made. The seal is made with an impulse wire that heats up to melt and mend the material together. During the seal, the vacuum sealer will have a way to press down on the bag to help weld the material together. Once heat stops impulsing through the sealing wire, a cool-down time is needed. Below is an image of textured home-use bags vs thicker smooth bags.
The cool-down process allows the sealed materials time to cool down. During sealing, the material is heated for mending. The extra time of rest after the seal is made ensures the open ends properly form a closure. A general rule is for the cool-down time to be double the seal time. Thicker bags will require longer seal and cool-down times.
The overall goal of vacuum packaging is to close off products from exterior elements. The bag type and seal are two key factors in accomplishing that goal. Upon completion of the cool-down cycle, the sealer can be opened and the bag removed.
First, inspect the sealed area for any wrinkles in the seal. One small crease can allow air into the bag and make the seal obsolete. After a visual inspection, grab the top of each bag side and lightly pull it apart. A strong seal will not come apart and should be as strong as other sections of the bag. Weak seals will easily pull apart with little force. Products should be protected and secure with a good seal and no punctures in the bag.
Vacuum sealing bags is an easy process. Insert the bag into the sealer > wait for a seal and cool down > and inspect the bag upon completing the process.
The small things are what matter when vacuum packaging with bags. The right bag is most important when creating a vacuum. Bags with no oxygen barrier will allow oxygen into the package every time. Coupling with suitable bags is the correct sealing wire. Too small of a wire will not properly seal and close the bag. If using a home use vacuum sealer, use a 3 to 4 mil channeled/textured bag and nothing thicker. For more information about vacuum sealing bags or custom sizes, call 1-800-441-5090.