Machine Design in DWOC2.0

Transcription

1 2.0 Machine Design in DWOC2.0 Production machine design for new cellulose-based products Ville Klar Doctoral Candidate Aalto University, School of Engineering Department of Engineering Design and Production

2 Why filaments? Strong form Building block for other shapes and structures Many established processes Filaments or fibre yarn

3 Raw materials Applications Machine elements Process parameters 3

4 Raw materials New processes required in spinning from fibre suspensions Development of sections of the spinning line required Established solution spinning technologies not directly applicable Multiphase fibre suspension different rheological properties Forming (drawing) and axial alignment of fibres Drying & dewatering

5 Raw materials Fibre properties Stiffness comparable to Kevlar [1] Tenacity comparable to glass fibres [2] Fibre properties and yarn properties not directly comparable (fibre network) Native wood cellulose structure Cellulose I structure is 50 % stiffer than the Cellulose II structure [1] Cost and raw material efficient processes Development required in production of raw materials Helicoidal structure [3] [1] Sakurada, Ichiro, Yasuhiko Nukushina, and Taisuke Ito. "Experimental determination of the elastic modulus of crystalline regions in oriented polymers." Journal of Polymer Science (1962): [2] Saito, Tsuguyuki, et al. "An ultrastrong nanofibrillar biomaterial: the strength of single cellulose nanofibrils revealed via sonication-induced fragmentation." Biomacromolecules 14.1 (2012): [3] Emons, Anne Mie C., and Bela M. Mulder. "How the deposition of cellulose microfibrils builds cell wall architecture." Trends in plant science 5.1 (2000):

6 Machine elements Wet spinning [5] Dry spinning [4] Dry-jet wet spinning [5] [4] Dry spinning, [5] Introduction to solution spinning,

7 Machine elements Wet strength Axial alignment of fibres Drawing Pump Spinneret Bath Forming Drying Spooling Rheology of the suspension Filament geometry Efficiency

8 Machine elements: Spinneret Headbox of spinning Iterative prototyping Phenomenological study of a coaxial spinneret

9 Process parameters Flow rates (ml/min) Agitation of suspension (thermal, ultrasound, mechanical) Conductive/convective/radiation Air flow / pressure Drying time Drying temperatures Pump Spinneret Bath Forming Drying Spooling Spinneret diameter (mm) Air gap (mm) Spinneret geometry / type (cylindrical, conical, double conical, hyperbolical, etc.) Bath liquid Plying Bath temperature Coating Drawing ratio Post-treatment Drawing sequence Compression / twisting Roll / godet geometry, surface, configuration

10 Process parameters Raw material properties Suspension parameters Spinneret geometry Timescales Forming parameters Drying parameters Filament properties Production rates Analysis of the effect of spinning parameters

11 Process parameters Prototype coaxial spinning line Different parameters measured and controlled Efficient testing of different spinning parameters in a fume hood with sufficient production rates

12 Applications Composites Filaments Nonwovens Textiles Design Applications

13 Applications Sufficient production capability Sufficient lengths of filaments Sufficient filament properties Weft-knitted sample

14 Applications Filaments are the first step Additive manufacturing Combined processes

15 Conclusions New processes based on native wood fibres can be greatly improved by developing new machinery Effects of spinning parameters can be efficiently studied through automation and control Scalability can be studied through prototype spinning lines Development of spinning leads to different processes for new applications