Influence of material and roll properties on roll deposit formation in flat film extrusion
In flat film extrusion, deposits on the chill rolls affect the surface quality of the films and lead to process instabilities. In the “Roll deposit” project, IKV has developed a detection system that allows the build‑up of deposits to be monitored and quantified in‑line during operation. The follow-up project (Roll deposit II) is to investigate the role and interaction of factors drying and degassing of materials, roll material and surface roughness in more detail.
© IKVOne key question is how deposits originating from low-molecular-weight constituents in the granulate can be affected by targeted drying and degassing of the material. In addition, it is investigated whether the interaction between polymer and metallic surface promotes the formation of polymer-metal ion complexes and thus further accelerates deposit growth.
A modular test roll with interchangeable segments is employed in the project, enabling a direct comparison of different roll materials and surface topographies (Fig. 1). Deposit formation during operation is continuously monitored using an optical camera system, allowing changes and growth rates to be documented over time. By systematically varying melt and roll temperature as well as the drying and degassing strategy, the interactions between process settings, material properties and roll surface can be elucidated. This will enable plastics processing companies to better assess which adjustments to material conditioning, process control or roll surface specification contribute to a tangible reduction in roll build-up, thereby extending cleaning intervals, reducing waste and increasing operational reliability.
Project data and funding
We would like to thank the BMWE for funding the IGF project (funding code 24512 N) and the project partners for their cooperation.
Project duration: 01.11.2025 – 31.10.2027
