Scale-up for Highly filled Materials – SCALE4MAT

The joint PIMM / 4D Pioneers laboratory aims to refocus 4D Pioneers' R&D activities on the optimisation and market deployment of innovative materials. The technology covered by the laboratory's work is based on the formulation of new innovative materials characterised by high filler contents, their manufacture by twin-screw extrusion and their processing by additive manufacturing. The dual objective is to enhance the company's skills by bringing in the PIMM's expertise in melt processing. For the laboratory, an increase in skills in hybrid biosourced polymer technologies for incorporating high filler contents.
This proposal is the culmination of a close partnership between the 2 partners since the creation of the company through service contracts and participation in joint projects, and will enable the scientific partnership to be consolidated on a long-term basis.
This joint laboratory project, SCALE4MAT, aims to remove the scientific and technical barriers to the melt shaping of highly filled polymers by integrating an approach based on skills in processing, rheology and the physico-chemical and structural characterisation of polymer materials.
2 materials are the subject of this initial programme and will form the scientific basis of the joint laboratory:
- 4TUNATA (highly filled polymer) developed by 4D PIONEERS, which has fire protection properties (certified for aeronautics and railways) but poor mechanical performance,
- Materials for MIM (metal injection moulding), which are polymer-metal hybrid materials that require debinding and sintering to obtain pure metal parts.
With a view to producing parts from these 2 materials, the joint laboratory will be investigating a number of issues:
- When the formulations of the 2 materials presented above were run on an industrial twin-screw extrusion line, a number of scientific problems arose: (i) filler dispersion problems, (ii) impurity problems, (iii) extruder parameterisation on a complex industrial line resulting in high throughputs. The aim is to ensure the reproducibility of the formulation developed in the laboratory in an industrial environment. To achieve this, 4D PIONEERS wants to determine a law of similarity to facilitate the transition between the laboratory and industrial scales while (i) optimising the transposition of parameters and (ii) ensuring the dispersion of fillers within the polymer matrix.
- One of the steps concerns the printability of the materials. Because of the nature of the polymer matrix (semi-crystalline) and the high filler levels, printing the materials developed is complex. Printability will be optimised by adjusting formulations, shaping parameters and printing tools.
- The incorporation of a continuous fibre within the polymer matrix will be studied with a view to reinforcing and consequently extending the attractiveness of the material, for example 4TUNATA for the transport industry. The PIMM laboratory will contribute its expertise in sizing and fibre/matrix compatibility, thus ensuring the implementation of this thermoplastic material.
- Work on MIM formulations with a view to limiting porosities detrimental to mechanical properties will be the final focus of the programme. Cyclic giga fatigue will be used to characterise fatigue behaviour. The aim is to study the influence of the filler rate, the state of these fillers (i.e. morphology, size, nature, oxidation) and their distribution, in order to study their influence on the properties of the various stages of the 3D MIM process.
This work will lay the scientific foundations for the SCALE4MAT laboratory, based on better control of polymer-filler blending processes, their shaping by additive manufacturing and consideration of the various stages of MIM implementation.