Simulation software for co-kneader extruders – LUCOMAX

Single screw extruder is the continuous equipment mostly used in the domain of polymer processing, used for final or semi products. Among the derived techniques, the Buss Kneader has the particular design of a barrel equipped with pins on its inner surface coupled to a discontinuous screw (in order to leave room to barrel pins) that translates back and forth while rotating. This coordinated kinematics leads to complex flows ensuring efficient mixing and homogeneity of material. This technology is indeed very adapted to thermosensitive materials, highly filled compounds or for plasticizing PVC compounds.
New generation compounds not only have to meet required technical specifications of durability, aesthetics, safety, maintenance but also have to ensure widened features: fire-proofing properties, health, bacteriostatic and antistatic constraints. Formulations are more and more complex and deadlines shorter and shorter. In spite of this, equipments type Buss kneaders are considered most of the time as black boxes. The effects of the conditions of flow (due to geometry, to kinematics) on materials, their plasticizing and mixing are very difficult to quantify. It is well known today that numerical simulation is the required tool to answer the questions of understanding, control and optimization of industrial processes.
To be predictive, numerical simulation needs to integrate pertinent flow models as well as material evolution models. This second point, before being mathematically written, must be studied and characterized. On the basis of this approach, LUCOMAX is devoted to control all various phenomena occurring in a type Buss kneader, then to set up a simulation tool able to perpetuate the knowledge, whose value analysis will be performed by end-users. To reach these objectives, the LUCOMAX project
- merges three industrial companies in the field of flooring and interior coverings (Gerflor), cable-manufacturing (Acome) and chemistry (Arkema); a software edition company (SCC) and two research laboratories specialized in the study of materials (Ingénierie des Materiaux Polymères) and processes modeling and simulation (CEMEF).
is organized in 4 technical tasks and one task for project management.
Task 1 is dedicated to the study of the phenomenological aspects of the flow in Buss type kneaders and materials characterization. It will define measurable objective variables able of link process conditions to product quality;
Task 2 sets up a mechanical model of global approach allowing flow simulation and quantification of the objective variables defined in the first task;
The integration of this model into an existing software platform available to the industrial users is the task 3. The selected software platform is the one of the software Ludovic® (dedicated to the flows in a twin-screw corotative extruder) because the global mechanical model will be close to Ludovic®'s one and because the industrial problems for these equipments are similar;
Task 4, leaded by industrial end users, sets up the validation configurations and analyze the added value brought by the three previous tasks regarding the industrials practice.
Within subtask 5, project coordination for administrative and technical points of view will be done in order to ensure the best work conditions. Three main points will be carried out:
- project management in accordance with the work program
- edition of progress reports
- internal and external communication.