Exploring The Different Kinds Of Shrink Tunnels
Feb 24, 2022
If you are entering the market for a shrink tunnel machine, you will find yourself with a big variety of different types of machinery. Some machines work with steam. Others use hot air. Every kind of shrink tunnel is designed to work for specific applications.
What Exactly Is A Shrink Tunnel?
A shrink tunnel (also commonly known as a heat shrink tunnel) is a metallic tunnel that sits above or is built around a conveyor. The tunnel has a heating element that heats the products as they move through the machine. Your products are conveyed through the tunnel and are cloaked with loosely fitting shrink film. When your products move past the heating elements, the film shrinks uniformly around the items as they are exposed to the heat.
Different types Of Shrink Tunnels
Steam Shrink Tunnels
Steam shrink tunnels use steam rather than hot air to produce the heat required for shrinking plastic substrates on products. Steam tunnels are most commonly used for tamper-evident packaging applications, such as shrink sleeves.
While steam shrink tunnels are not pneumatic machines, and therefore do not require an industrial level air compressor, they do require a water supply. As such, when considering purchasing a steam shrink tunnel, you need to understand that these machines will be more expensive because they require the use of a utility.
Self-Contained Steam Shrink Tunnels
There is a variation of the steam shrink tunnel known as a self-contained steam shrink tunnel. The self-contained tunnel differs from the standard steam tunnel in that it has an internal steam generator which generates the steam without additional attachments. In contrast, the traditional steam tunnel needs steam piped into the machine which requires additional components.
Steam shrink tunnels are specially made to run on product lines in which quality and high-end graphics are favored. If your products require spot on registration, brilliant colors, perfect fonts and long term consistency, steam shrink tunnels are for you.
Steam shrink tunnels allow for highly uniform heat transfers which are superior when compared to hot air systems. Steam-based machinery provides high precision registration capabilities and better shape forming. This means that the sleeves will fit tighter and more evenly and the graphics and aesthetics will look better on the sleeves resulting in better shelf appeal.
Steam tunnels are a good choice when packaging containers which are packed under high pressure or for packaging products that are flammable.
Hot air shrink tunnels
With hot air shrink tunnels (also known as convection shrink tunnels) the machines produce hot air which is blown onto a plastic sleeve that surrounds the item being packaged. The heat shrinks the sleeve around the product evenly.
The hot air is blown from a module known as a "baffle." These modules direct the heat in any required direction which allows for superior distribution of heated or cooled air. The packaging of cartons and boxes are common applications for this type of machine.
