In the production of film tubes using multi-bubble technology, biaxially stretched multilayer films are produced. They are characterized by high barrier properties, great robustness and high transparency. This makes these films ideal for food packaging.
In this process, the film tube is usually extruded vertically from top to bottom, blown up and then directly water-cooled. In order to achieve high barrier values and great stability, the foil is heated and cooled again in subsequent steps.
As a result of the further heating processes, there is a risk that the sealing layer on the inside of the tube will already bond during production. This is prevented by using KSL separation powders. The powder is sprayed onto the inside of the film tube immediately after extrusion. During the subsequent winding, an additional antiblocking effect is achieved. As a result, subsequent processing steps or handling operations can be carried out fully automatically without disturbing adhesion effects. Moreover, this facilitates the handling of the finished film products for the end user.
eskal – natural calcium carbonate
Because of high temperatures in the vicinity of the extrusion nozzle, we recommend to use our eskal powder made from natural calcium carbonate here. This mineral powder is temperature stable and non-flammable. Consequently, there is no risk of a dust explosion. Due to the usually vertical alignment of the tubular film, rather fine and therefore light powders such as eskal 10 and eskal 15 (plus) are typically used here. The individual grains of these powders are extremely fine, so that they are not visible on the finished product.
For an effective separation effect, it is crucial that the individual particles of a separating powder have approximately the same diameter. Our eskal powders guarantee this through combined grinding, sieving and (air) separating processes. This enables effective separation with a minimal use of powder. The application can be carried out fully automatically with minimal application systems.
Our eskal powders are fully suitable for contact with food. Calcium carbonate is widely used as food additive, even for organic food. Corresponding certifications according to European (e.g. 1935/2004/EG; 2023/2006/EG; 1333/2008/EG; 231/2012/EU; 2020/356/EU) and international regulations (e.g. FDA) are available and are renewed periodically. Moreover, our eskal powders are certified as Kosher including Passover.