Flow wrapping using a horizontal flow wrapper is the process of making a horizontal bag from a single roll of film. In order to seal the film, heat is applied at its bottom and its ends. Usually, an industrial vacuum sealer can do the work but in certain cases, you’ll need a specially designed horizontal flow wrapper.
There are a few common things in each and every wrapper. They are:
- Infeed conveyor
- A film feed assembly (back stand)
- A film-forming area (former)
- Bottom seal (finseal)
- A cutting head
- A discharge area
Products that are to be sealed via a horizontal flow wrapper are first placed on the infeed conveyor of the flow wrapper. There are two ways to do it.
- Hand feeding
- Automated feeding solution
As soon as the infeed conveyor delivers the product to the forming area, a film is drawn from the film feed assembly into the forming area. After that, a film tube is formed around the product and a bottom seal is created. Once a finseal is created, the film feed assembly and the product are delivered to the cutting head.
The cutting head then creates the end seal and it cuts the adjoining wrapped products into individual packages at the same time. It then delivers the packages to the discharge area.
You can then either cartoon it at a packaging station or accumulate it for packaging at a later time.
When it comes to a horizontal flow wrapper, there are two types of film.
- Hot Seal Film
- Cold Seal Film
Before deciding whether you should use a hot seal film or a cold seal film, decide the following first.
- Product Characteristics
- Material costs
- Necessary barriers (oxygen, ultraviolet, etc)
- Hermetic seal strength or integrity
- Required capacity and speed
Cold film seals consist of two things: a thin layer of glue and base material (carrier). In order to seal a cold film, you need to press two layers of glue together. The biggest advantage of using this type of film is that it can be used at a higher film speed than heat film seals. Moreover, you don’t need heat to seal it. This comes in handy when dealing with temperature-sensitive products such as chocolate. But, there are a few disadvantages as well. The first one being they can never offer the same protection and hermetic seal qualities as the heat seal film. Moreover, they need to be stored in a climate-controlled room.
Heat film seals are often multi-layered. And, they even consist of an outer coating that prevents them from melting. The materials such as polypropylene and a sealant layer are used on the interior as they have a lower melting temperature and bonds to seal the package together. If you need a high integrity seal, then heat film seals are a perfect choice. Moreover, it is cheaper than cold film seals.
The three most important things to keep in mind when producing a seal include:
- Heat: Temperature of the sealing surface
- Dwell: The amount of time for which the machine jaws are in contact with the sealing material
- Pressure: The total amount of pressure applied to the sealing material
Whenever you change any one of these factors, make sure that you adjust one or both the factors to compensate for this change. For example, when machine speed decreases significantly, the dwell time will increase, hence you need to adjust the temperature (or sometimes pressure) to compensate for this change.
Why choose Horizontal Flow Wrapper
There are a lot of benefits of using a horizontal flow wrapper to wrap your products. Flow wrap makes sure that the products are in a protective seal and increases the lifetime of food products. The benefits of a horizontal flow wrapper include:
- An extra layer of protection
- Flow wrap is customizable
- Increased throughput
- Fast changeovers
A horizontal flow wrapper, also known as horizontal form fill and seal (HFFS) machines contains 6 layers. And, the principles are the same for every horizontal flow wrapper. Just make sure that you use the heat film seal or the cold film seal depending on the characteristics of the product you want to wrap. The benefits of using a horizontal flow wrapper include fast changeovers, increased throughput, and more.