Cast film extrusion lines for a flexible and economic production

Cast film extrusion lines…
There is an increasing global market for high-quality cast films - both mono- and multi-layered.

Reifenhäuser has developed intelligent line concepts that enable cost-efficient production processes through a reduction in energy consumption and savings in raw materials.

The modular design of coextrusion lines is an important aspect with regard to the different applications of multi-layer structures. These can be produced on single-screw extruders, Reitruder co-rotating twin-screw extruders and gearless REItorque extruders.

Advantages of REItorque extruders:
The narrow design requiring about 30 % less space and the reduction in energy of about 8 % compared to conventional extruders are crucial factors in coextrusion lines.
Raw material blends using fillers can be processed on Reitruder co-rotating twin screw extruders by direct extrusion. In addition, this extruder type is also suitable to handle PET pellets and PET bottle flakes without a drier.

The REIcofeed II coextrusion system ensures a flexible layer distribution and close tolerances of the individual layers which reduces the consumption of expensive additives in the production of high-quality film structures of two to seven layers. The total film thick ness as well as the thick -nesses of the individual layers with in a composite can be precisely measured by means of an infrared thickness gauge.
Additional savings in energy can be obtained by using an intelligent heating-up program that copes with the different heating-up times of the individual extrusion components and controls the energy required.

Specially developed screws, adapted to modified melt temperatures of modern raw materials, ensure a good homogeneity of the melt and enhance the output capacity of a cast film line.

The copper shell of the cooling roll enables a significantly improved heat transmission (depending on the product) resulting in an increase in efficiency of the complete cast film line. This extrusion concept forms the basis for the production of high-quality thin films used as barrier, metallisable, laminating and stretch films, but also as standard consumer packagings for foodstuff and medical products. With this concept, Reifenhäuser has been able to reduce the energy consumption of cast film lines and increase at the same time the output capacity of film structures with a highly flexible layer distribution.