Shrink wrapping is a process in which heat is used to completely cover a product or package in tight film. The primary functions of shrink wrap or shrink film are to keep the product clean and attractively presented, to protect the product from superficial damage, create stability, and join multiple packages together.
Devices used to apply the film include sealers to seal the film around the product and heat guns or tunnels to shrink the film.
These manual, easy-to-use sealers have a single, straight bar that is used to cut and seal the shrink wrap around a product. They are typically designed for low to mid-volume use, such as with wrapping CDs, DVDs, software packages and other retail products.
The product is inserted between the two layers of centre-folded shrink film, and then the bar of the sealer is pressed down on one side to cut and seal that side. This is repeated on the other sides of the package to fully seal it. A heat gun or heat shrink tunnel is then used to shrink the film.
The advantage of this type of sealer is the ability to move and manipulate the shrink film around a product with ease. You can also seal multiple angles around a product and are not limited to a product with four sides. If used in conjunction with a heat gun, then you are not limited to the height of a heat shrink tunnel.
These sealers use an L-shaped bar to cut and seal film around a product in one step. They are typically designed for mid to high-volume use, depending on whether they are standalone or part of a combination shrink wrapping system. Standalone L-Bar sealers require a heat gun or heat shrink tunnel to shrink the film, while combination systems include a heat source.
L-Bar sealers come in either a manual option, where the operator has to manually press down the bar and lift it back up, or an automatic option, where a motor brings the bar down and back up. The advantage of an L-Bar sealer is that all sides can be cut and sealed at the same time, which speeds up the packaging process.
Heat guns are similar in appearance to a hair dryer. The heat gun is used to blow hot air over a wrapped product by hand, which causes the film to shrink.
Heat Shrink Tunnel
A heat shrink tunnel is the fastest way to shrink film around a package. It quickly and evenly applies heat to the film to shrink it, which takes only seconds. This is much faster than using a heat gun, and is ideal for mid to high-volume and industrial shrink wrap needs.
Tunnels can be sold separately or as part of a shrink wrap system. After the film is cut and sealed around the product, a conveyor belt sends it through a tunnel, heating and shrinking the film. The process is more automated and the finished product is more evenly shrunk than with a heat gun.
L-Bar Sealer with Chamber or Tunnel
Some models of L-Bar sealers incorporate a heat source to shrink the film, making it an all-in-one system. This heat source can be a chamber or hood over the L-Bar sealer, which blows hot air around the product once the film has been cut and sealed by the bar.
Other combination systems use a heat shrink tunnel for the heat source, in which the product is conveyed from the sealer to the tunnel. Shrink wrap systems with chambers or tunnels are the fastest and most effective way to package a wide variety of products, with the process taking only seconds.
The benefits of a combination system include:
Improved productivity, as one operator can complete the shrink wrapping process in a continuous operation.
A higher volume of products can be shrink wrapped in less time as you are not moving from one machine to another.
Less space is required, as two separate machines are not needed.
Shrink process can be observed in a chamber, which helps to ensure optimal results.
Less adjustment time is required between different package sizes and types.
Economical operation, with reduced energy consumption.