A Quick Guide for Food Packaging Methodologies

By Harpak-ULMA
Posted In : Flowwrapping, Food Packaging, Packaged Food, Manufacturing, tray seal, MAP, Plastic Packaging, vacuum seal, C-Pak, skin packing, stretch seal

There are several methods to package food. Which method is right for you?

Vacuum Packaging

The vacuum packaging method removes air and its contaminants prior to sealing. The process creates a cavity by heating and forming the film into a desired shape, introducing your products (fish, meat, poultry, cheese, sauces, etc.) to the packaging either manually or by automation, extracting all air and any particulates, then sealing occurs. There are several benefits of using vacuum packaging: longer shelf life, increased product protection, flavor preservation, and mold and bacteria prevention. It’s also cost effective and can be used with rigid or flexible packaging. Vacuum packaging is an efficient method when using the proper machines and materials.

Stretch Seal

Stretch Seal requires the film to be heat sealed to the flange, or top edge of the tray, rather than wrapping around the entire tray. This sealing technology prevents leakage and reduces costs on materials. Stretch Seal is ideal for poultry products because of its leak proof capabilities as well as the an extremely clear presentation. It also eliminates the need for shrink tunnels which are used by some equipment to heat and shrink the film to form around the product.

Skin Packing

In Skin packaging a top film forms over the entire products surface as well as any exposed material surface. This process involves lining the backing material, often corrugated cardboard or paperboard, with an adhesive material. Heat sealing permits the film to form a seal around the product while a vacuum is used to eliminate the atmosphere which would accelerate product spoilage. Industries and products such as processed and seafood, meat packaging machine manufacturers, poultry, automotive manufacturers, cheese packaging equipment, and ready could benefit from skin packaging. Some benefits of Skin packing include an extended shelf life, flavor retention, product clarity, vertical display and options for flexible or rigid support. It’s often used in retail so consumers can see a product without having to open it. Skin packaging can occur using a thermoformer or a tray sealing machine.


Cryovac Darfresh technology is similar to skin packaging, but offers an additional layer of support with a second tight, form fitting skin that seals to the edge of the product. Compared to normal skin packing technology, Darfresh offers zero film scrap and up to 38% less top film usage. Also, 20-30% more trays per minute can be produced than traditional technology. The Darfresh packaging method is useful for products that contain liquids, uses easy-open film, offers clear visibly for the product, superior oxygen barriers, and contributes to an extended shelf life.

Tray Sealing

Tray sealing machines seal a rigid tray with food product inside and heat seals a plastic film to the trays flange. Tray sealing is ideal for packaging both frozen meals and fresh foods. The seal is airtight and can be used with Modified Atmosphere Packaging (MAP) technology, which prolongs the products shelf life by slowing down harmful bacteria that causes spoilage, and as a simple dust cover for frozen products where no MAP requirements exist.

Flow Wrapping

The finished wrapping of a flow wrapper has a seal that is referred to as a non-lap type seal on the bottom and crimped end seals. In other words, the product is sealed at the top and bottom with a longitudinal seal down the middle – think of the wrapping for a candy bar, power bar, frozen novelties, vegetables, or burritos. The process is completely hygienic and is aimed at both food and non-food markets. It can offer resealable options as well as MAP to prolong shelf life.

Vertical Flow Pack Tight Bag System

The Vertical Flow Pack Tight Bag packaging method ensures product safety because there are no perforations. The bag was developed on vertical form fill and seal (VFFS) machines to preserve the quality of the product by optimizing the required volume of the bags. These bags are optimal for frozen foods and is a fully closed bag system. The Tight Bag also offers an air evacuation system to minimize packing material and shipping space as well as reducing oxidation within the package.


Thermoforming is when a tray or a cavity is formed from rollstock, then another roll of film is placed over the product and sealed with the bottom film. This creates a horizontal form, fill, and seal. A thermoformer machine offers the ability to do MAP, vacuum, skin, and shrink capabilities. A thermoformer can also do multi-cavity packs, have easy open and reclosable systems, and use multiple films in one pack. A thermoforming machines for food is used for many products throughout several industries such as cheese sticks, but can also be used in non-food packaging, such as processing medical devices.


The C-Pak packaging method is a unique proprietary re-closable food packaging system that maintains freshness using a tray sealing machine and rigid lidding solutions. CPAK is a two-step system where a rigid tray is loaded with product; cheese, snacks, candies, etc.  MAP is introduced if necessary, sealing below the flange occurs, and finally a “snap-in” lid finishes the tray.  It keeps the contents of the package fresh, is easily re-closable and can be presented on shelves in multiple ways.

Modified Atmosphere Packaging (MAP)

The goal of MAP is to extend the shelf life of products. MAP lowers or eliminates oxygen inside the packaging because oxygen speeds up the process of spoilage. Oxygen encourages the growth of bacteria, produces lipid oxidation reactions, and causes high respiration rates causing spoilage.

The air in the package is replaced by gas mixtures that help extend the products shelf life. Some common gases used are carbon dioxide, oxygen, nitrogen and carbon dioxide. Nitrogen is used to prevent oxidation and helps prevent package collapse. The packaging method of replacing the oxygen with a MAP gas uses gas flushing. It happens by passing a stream of gas – the air becomes diluted, then the pack is sealed.

Advantages of MAP :

  • Less food waste from spoilage
  • Increased shelf life: 50-500% increase
  • Reduction is costs: storage, labor
  • Improved presentation
  • No chemical preservatives
  • Flavor preservation

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