Hot air is ideal for the processing of shrink films and shrinks tubes because when plastic is heated it curls and bends.
There are two main areas when it comes to heat shrinking. Heat shrinking within packaging technology and heat shrinking in electrical engineering.
Typically used to achieve high heat are Leister hot air blowers and heaters. Leister heaters, blowers, and hot-air tools are used in all areas in which hot air is conceivable in the manufacturing process: mechanical engineering, auto, food, packaging, and building industries.
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 usually is placed around the product being packaged. When the shrink tube 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 lipstick) and entire pallets that have been loaded with goods. Hot air shrinking also is widely used in beverage packaging applications.
1. 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.” The shrink sleeve may only cover a portion of the bottle or may extend across the entire height.
2. Another typical application is the use of shrink film to create a pack of between six and twenty-four bottles or cans.
3. 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 close.
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, heat shrink tubing is used for electrically insulating bare wires, combining several cables, and protecting contacts. The tubing is available in various sizes and the material usually is safe against fire. Leister offers hot-air blowers in conjunction with shrink nozzles that are appropriate for this particular application. This enables the heat shrinking process to be completed quickly and safely – whether you are performing it manually or producing cable harnesses within an automatic system.
Conclusion
An air heater works by passing air across a heated element to elevate the temperature of the air. Hot air can be used for various applications ranging from heating a space to drying coatings and parts, or from de-flashing plastic components to heating parts in the manufacturing process. If you want to learn more, check out our latest article on how to choose the best blower.