Posts Tagged ‘packaging machine’

Shrink Wrapping Explained

Shrink wrapping, also known as shrink wrap packaging, is the term used to refer to the covering of a product that is a clear or transparent, and in some cases, printed plastic film. This film is wrapped around the product. Then, it is sealed together in all sides, which would look like a loose bag around the product. Using a heat shrink tunnel or a heat gun, the film is shrunk tightly, wrapping the product in a skin-tight finish.

The following are the four types of shrink wrap system:

The Transit Wrap

With the transit wrap system, the product goes through a curtain or a sleeve of film. After shrinking the film on the product, the shrunken film usually leaves open ends, which is also known as bull’s eyes. Complete wraps can be possible with this type of wrap system using specially ducted shrink tunnels. However, the resultant seal is not attractive enough for display. The film used for the transit system is primarily polyethylene, which is the cheapest film on the market.

 

The L-seal Wrap

This style of shrink wrap system is used for mainly for display purposes. This system uses a sealing and cutting arm in the shape of the letter L. With the film, the product is inserted to the sealer, which then seals and cuts the other two sides, trimming away and removing the excess film. Polyolefin or PVC film is widely used in this type of wrap system. This film has 40% shrink property when heat is applied.

As the shrinking takes place, the film must be punctured or pricked to allow the air to escape. This means that the wrap is not airtight, which could allow some transfer of aroma and bacteria. However, the holes are so small that they are hardly noticeable. You can position the holes in a way that they are in contact with the edges of the product that you are wrapping.

 

The Flow Wrap

The third type of shrink wrap system utilizes the flow wrapping technology. At regularly spaced intervals, the product is loaded into the tube of film. Simultaneously, the film is formed over a “shoe”. A fin seal is created under the package and the ends are sealed with a blade. This type of system is commonly used in wrapping magazines. If you want to achieve a skintight finish, use a shrink tunnel. Or, you can just simply leave a loose wrap.

 

The Sleeve Shrink Tube

The sleeve shrink tube or shrink label is the wrap system, which is typically used for packaging bottles. A tube of film is dropped over the bottle to be wrapped before it passes through a shrink tunnel and heated. The tube film then shrinks, fitting tightly around the bottle. With this type of shrink wrap packaging, the film can provide a decorated label for the pack. In some cases also, it is used as a security device wherein the lid connects the bottle or jar. This wrapping technique is called shrink sleeving.