Hot air is ideal for processing shrink films and shrink-on hoses.
There are two main areas:
heat shrinking within packaging technology and heat shrinking in electrical engineering.
Packaging
Shrink films are often used in the context of packaging. These films have been stretched during the manufacturing process and when heated return to their original shape because of what is known as the "memory effect". During packaging, a tubular shrink film is usually placed around the product being packaged. When it is subsequently heated with hot air, the film constricts until it hugs the packaged product. This process is used both for small products (such as lipsticks) and entire pallets that have been loaded with goods. Hot air shrinking is also widely used in beverage packaging applications.
- Instead of having a label applied to them, individual bottles are often wrapped in a decorative shrink-on hose, which – in this case – is referred to as a "sleeve". This may only cover part of the bottle or may extend across the entire height.
- Another typical application is the use of shrink film to create a pack of between six and twenty-four bottles or cans.
- Shrink-on caps are placed over wine bottle closures (screw tops or corks) to protect them against dirt or for decorative purposes. When these preformed caps are exposed to hot air, they shrink tightly around the neck of the bottle and closure.
The following materials are commonly used for shrink films, depending on the application: polyolefins (PP and PE), PET, and PVC.
Electrical engineering
In the field of electrical engineering, shrink-on hoses are used for electrically insulating bare wires, for combining several cables, and for protecting contacts. They are available in various sizes. The material is usually safe against fire. Leister offers hot-air blowers in conjunction with shrink nozzles that are appropriate for the application concerned. This enables the heat shrinking process to be carried out quickly and safely – whether you are performing it manually or producing cable harnesses with an automatic system.
Leister has the solution
With Leister air heaters and hot-air blowers, you can process shrink films and shrink-on hoses of any size in all kinds of applications. Thanks to the precise temperature control, the process is easy to automate and runs quickly and safely.