Bandaging Film

The rubber coating on rollers and rolls, as required in many areas of industrial manufacturing, is applied by vulcanization. To ensure that the rubber compound remains “in shape” on the roller shaft during the vulcanization process, it is held in place by bands. These bands can be made of nylon, cotton, or viscose. As a cost-effective alternative to these bands, bandaging film made from plastic films has proven successful. The film material is already less expensive than the traditionally used bands in terms of material costs alone, thereby reducing production costs. In addition, the use of film simplifies the work steps involved in preparing for vulcanization. This results in shorter production downtimes and further cost minimization.

Bandaging film is made from heat-resistant materials such as polyimide, polyethylene, or BO-PET. These materials offer good temperature resistance, flexibility, and tear strength, making them suitable for the high demands of the vulcanization process. In addition to heat resistance, high tear strength is a particularly important property for bandaging films, as a tear in the film can lead to irregularities in the vulcanization process, which in the worst case can render the roller unusable.

The technical film optimont® 501 is the film of choice from the Bleher product range when it comes to use as a bandaging film. Since the vulcanization process involves high temperatures, the heat resistance of optimont® 501 is one of the key properties of the film. Tear strength and dimensional stability are also important characteristics for its use as a bandaging film.

The basis of optimont® 501 is so-called BO-PET material. The properties mentioned above are achieved through the stretching process, in which the polyester film is stretched in both the longitudinal and transverse directions immediately after production. A polyester film treated in this way is referred to as biaxially oriented, which is where the name BO-PET originates. Through the stretching process, the crystalline structure of the film is modified in such a way that high mechanical strength and heat resistance can be achieved.

Bandaging film is wrapped tightly and evenly around the roller core and the applied rubber compound. The wrapping process starts at one end of the roller and proceeds in a spiral pattern to the other end. To generate uniform pressure, the overlap of the film must be kept to a minimum. Prepared in this way, the roller is subjected to the vulcanization process, during which the rubber compound becomes an elastic mass that firmly adheres to the roller core. The bandaging film applies pressure to the rubber mixture, pressing the rubber compound together with additives such as sulfur tightly against the core, thereby ensuring an even distribution of rubber around the roller core. Irregularities such as blistering in the roller rubber are also prevented by the pressure exerted by the bandaging film. The bandaging film thus ensures a homogeneous structure of the rubber coating on the roller.

Selecting the appropriate bandaging film depends on various factors, including the size of the roller, the vulcanization process, the required temperature resistance, and the pressure involved. Based on the specific process requirements, specialists select the suitable film. Please contact our service team once you have defined your specific requirements for a bandaging film. Our advisors can answer many of your questions or provide samples for trial runs.

optimont® 501 is not only suitable for use as a bandaging film; this polyester film is a technical film with a wide range of applications. The film can be printed, and laminations can also be easily carried out on the adhesion-enhanced surface. Viewing windows for cardboard packaging can also be produced from the bandaging film, and because the film is food-safe, it can likewise be used for food packaging. In addition, this heat-resistant, mechanically highly resilient, and dimensionally stable BO-PET film can be used in various technical applications as a release film, carrier film, or protective film.

Polyester film is still largely produced from fossil raw materials and is therefore not inherently an environmentally friendly material. However, PET benefits from a well-functioning recycling system, with around 90 percent of PET bottles produced in Germany being recycled. This makes PET one of the plastics with the highest recycling rates. At Bleher, we offer optimont® 501-R-PET as a bandaging film, which is manufactured from more than 90 percent post-consumer recycled material. Producing films from recycled granulate saves significant amounts of water and energy.

In the Bleher product range, optimont® 501 is available in thicknesses from 7 to 250 μm, while optimont® 501-R-PET is offered in thicknesses from 12 to 175 μm. As bandaging films, these films can be adapted to a wide range of requirements. For other areas of application, the broad range of film thicknesses opens up numerous possible uses.