Case in twelve phases
1The company and starting situationA plastics processor produces film based on a bio-based compound. The order portfolio requires a capacity increase from 350 to 900 kg/h.
2The technical goalMore than doubling the production rate while maintaining layer-thickness tolerance and preventing thermal degradation of the bio-based material.
3The technical bottleneckAt higher throughput, the melt viscosity shifts unexpectedly and unstable layer thickness occurs; moreover, local overheating initiates degradation. Settings from petrochemical practice are unusable: the behaviour is insufficiently understood.
4Why known technology fell shortThe existing screw design with standard temperature profiles has been systematically tuned. Extensive test series with the existing design also did not restore a stable window: the problem lies in the combination of material behaviour and higher speed, not in the settings.
5Investigated solution directions(a) New screw geometry with barrier elements for reliable melt formation. (b) Self-developed temperature zoning with a refined GC temperature profile. (c) Model-based process control that compensates viscosity shifts predictively.
6ExperimentsTest runs at pilot scale with inline viscometry, DSC analyses of taken samples, systematic measurement series across the target range and iterative improvement of geometry and control.
7Technical resultA stable process window at 850–900 kg/h within the layer thickness tolerance, with degradation below 1%. The new process route was thereby demonstrated at pilot scale.
8What qualified as R&DThe development of a technically new combination of screw geometry, temperature zoning and process control with which the abnormal flow behaviour and degradation behaviour of the bio-based material had to become manageable. The experimental test runs and measurements were part of demonstrating this new process principle.
9What did not qualifyThe capacity increase as such, the construction and installation of the production line, routine quality control and production.
10More than scaling up?The WBSO did not lie in increasing the capacity as such. At higher throughput, new and technically ununderstood material and flow behaviour arose, making known process settings unusable. Precisely solving that technical problem constituted the development work.
11Where the WBSO project endedWhen the new process principle was demonstrated at pilot scale, the R&D phase ended. Engineering of the final production line and implementation fell outside it.
12Which project records belonged to itProcess logs per test run, measurement series, screw design drawings and revisions, material analyses (DSC, viscosity) and research notes.
