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MCF Korea-2012
- 1. LG. Korea 2012 āInventing Plastic Microcapillary Filmsā BY MALCOLM MACKLEY. With Acknowledgement to; Dr Bart Hallmark Dr Christian Hornung Dora Medina Sina Bonyadi and Hui Cheah Nuno Reis Frederik Scheiff, David Agar and Matthais Mendorf DEPARTMENT OF CHEMICAL ENGINEERING AND BIOTECHNOLOGY. UNIVERSITY OF CAMBRIDGE. mrm5@cam.ac.uk 1
- 2. Plastic Fantastic Sub millimetre Process Engineering 2
- 3. Conventional Foaming Processing high pressure gas hopper metering device static mixer nucleation Polymer plasticating screw Band heaters Plastication Polymer/gas solution Nucleation of polymer formation and Cell growth 3
- 4. Background. Plastic Micro Capillary Films (MCFs) Bart Hallmark and Malcolm Mackley 2005 4
- 5. 5
- 6. Early experiments 2002 Gas injector Convergent die Edge of quartz window Hopper Flange with filter P2 T5 T6 Motor Screw T7 T1 T2 T3 T4 P1 Gear pump Heated Die barrel F Haul off Nitrogen supply Secondary Rotameter Hollow extrudate Primary pressure pressure Gas flow regulator regulator control PE 6
- 7. MCF Process Development Gas entrainment Convergent die Edge of quartz window Hopper Flange with filter P2 T5 T6 Motor Screw T7 T1 T2 T3 T4 P1 Gear pump Heated Die barrel Haul off Hollow extrudate Hallmark et al. J. Non-Newtonian Fluid. Mech (2005) 7
- 8. Gas entrainment ā die and injector design Polymer flow Die land MCF extrudate Melt drawing length, L Brass ārollerā Quench bath Extrudate to haul off 8
- 9. Low voidage MCF 9
- 10. Die design 10
- 11. The MCF process Die exit Direction of flow Polymer melt Entrainment Chill rollers body MCF Array of 19 entrainment nozzles PLAN VIEW Quenching length, L Air inlet Single screw extruder MCF extrusion die P2 T5 T6 Chilled rollers MCF T1 T2 T3 T4 Spooling Gear pump Guide rollers 11 Hallmark et al Adv. Eng. Mat., (2005).
- 12. Initial die voidage A2 Ļ1 = = 9.6 % A1 A1 + A3 A2 A2 + A3 = 10.3% A3 Ļ2 = A1 12
- 13. Low Voidage MCF Standard MCF 250 200 Hydraulic diameter (Ī¼m) 150 100 50 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 Capillary num ber 340 Ī¼m MCF voidage ā 9-11 % 13
- 14. Drawing Low Voidage MCF D. I. Medina B. Hallmark T. D. Lord M. R. Mackley The development of voidage and capillary size within extruded plastic films. J Mat Sci, in press 14
- 15. Mechanical Drawing of MCFs (using stable Microsystems texture analyser) Upper Clamp Upper Clamp MCF MCF Fixed lower clamp Fixed lower clamp Room Temperature Mechanical drawing process - Increases orientation but 15 limits drawability
- 16. Diameters after Mechanical Drawing of MCFs 210 200 190 180 Standard MCF 170 160 150 Hydraulic diameter (Ī¼m) 140 130 120 110 100 90 80 70 60 50 40 Diameters after Mechanical Drawing 30 20 10 0 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 Capillary number 16
- 17. COLD DRAWN Necking 120 Undrawn material 100 Material Hydraulic diameter (Ī¼m) 80 in neck 60 Post-neck material 40 20 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 Capillary number MCF voidage ā 8.5 % 17
- 18. HOT DRAWN 25 Optic micrograph of top view MCFs 20 Drawing Hydraulic diameter (Ī¼m) direction 15 10 5 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 Capillary number MCF voidage ā 9-11 % 18
- 19. Molecular orientation Quenching X-Ray diffraction Extrusion die little orientation Extruder Melt T=170 Ā°C Chilled rolls 9 Ā°C MCF High orientation Hot drawing Solid - Second stage Hot draw- Thermal camera image V2 V1 Draw ratio Ī» = V1/V2 Hot roll T = 60-120Ā°C 19
- 20. Optic micrograph Drawing MCF Product from of top view MCFs direction continuous drawing 100 Ī¼m 200 180 Hydraulic diameter (Ī¼m) 160 140 120 100 80 60 40 20 0 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 Capillary number 20
- 21. High Voidage MCF D Medina J Mat Sci 2008 21
- 22. High Voidage MCFs By rapid cooling and or injecting air under pressure into capillaries during melt processing it is possible to produce Develop orientation āHigh voidage MCFsā Conventional extrusion line MCF High- extrusion speed die air quench P2 T5 T6 Chilled rollers T1 T2 T3 T4 T Spooling P P Mass flow control valve Compressed air Guide rollers Isolation Needle valve valve P Pressure sensor Manual valve T Temperature sensor Control valve 22
- 23. High voidage MCFs Hydraulic diameter varies from 200 Āµm 150 Ī¼m to 417 Ī¼m 100 Ī¼m MCF-MCF hv2- big voidage 350 300 Hydraulic diameter (Ī¼m) 250 200 150 100 50 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 23 Capillary number
- 24. X-Ray (200) (110) Orientation present Air quench jet Die exit Solid MCF Air entrainment needle Extrusion direction Solidification Interface zone Melt residence time << 1 s Molten Melt relaxation time < 1 s MCF Chill rollers Air quench jet 24
- 25. High-voidage MCF Air quench jet Die exit Solid MCF Air entrainment needle Extrusion direction Solidification interface Molten MCF Chill rollers Air quench jet 2D schematic Asymmetry in temperature profile ļØ Asymmetry in viscosity profile ļØ Asymmetry in the velocity profile To << Ti Ī·o >> Ī·i Ī·o T o A1, u1 A2, u2 Ī·i T i Injector needle 25Symmetry plane
- 26. Ultra High Voidage MCF D. I. Medina B. Hallmark T. D. Lord M. R. Mackley The development of voidage and capillary size within extruded plastic films. J Mat Sci, in press 26
- 27. Mechanical drawing of High Voidage MCFs Capillary direction Upper Clamp Upper Clamp MCF MCF Fixed lower clamp Fixed lower clamp Room Temperature It breaks 27
- 28. Mechanical drawing of MCFs Transverse direction Upper Clamp Upper Clamp MCF Fixed lower MCF clamp Fixed lower clamp 28
- 29. HV-MCF is unfolded to form the UHV-MCF Go to MCF UHV movie Dora Medina 29
- 30. ULTRA HIGH VOIDAGE MCFs SEM UHV-MCF 1000 Ī¼m 1000 Ī¼m 30 1000 Ī¼m
- 31. High Voidage die Bart Hallmark 2008 31
- 32. Initial die voidage A2 Ļ1 = = 30% A1 A1 + A3 A2 A2 + A3 = 60% A3 Ļ2 = A1 32
- 33. High Voidage Die ā some interesting results Melt draw, chill rollers, haul off Die quench, haul off 33
- 34. Microcapillary Monoliths 34
- 35. An addition to the MCF family ā Microcapillary Monoliths (MCMs) 200Ī¼m 7mm 500Ī¼m Christian Hornung 35
- 37. MCF Development; Pressure Drop Christian Hornung 37
- 38. MCF Development RTD PE, EVOH and FEP 50 45 length = 20 m inlet flow rate = 0.5 ml/min outlet 40 35 30 c [mg/l] 25 20 15 10 5 0 0 5 10 15 20 25 30 t [min] 38
- 39. MCF Commercialisation ļ 2 flat silicon heaters (200 W each) ļ PID control - Temperature monitoring at top and bottom heater plates developed by ļ Tmax = 150 Ā°C Lamina Dielectrics Ltd. & Cambridge University Reactor disk tray Temperature control Teflon coated hot plates Patrick Hestor Lamina Ltd 39
- 40. MCF Development; Microflow Video, Methanol Nuno Reis Organic. into Veg oil Kerosene, 1.8 mPas Oil, 27 mPas Vegetable oil. 50 mPas Water, 1 mPas, glycerol 10-50 mPas or methanol 40
- 41. MCF Development; Slug separation Scheiff et al. Lab on a Chip. 2011 41
- 42. Multi channel flow Go to MCF multi channel flow Nuno Reis 42
- 43. MCF Development; Biodiesel Microreactor Input Output Vegetable oil Biodiesel Methonal plus Glycerol catalyst Microcapillary Flow disc 43
- 44. MCF Microreactor; Biodiesel Methanol Glycerol Veg oil Biodiesel Methanol plus Glycerol catalyst 44
- 45. MCF Protein Assay Nuno Reis and Al Edwards FEP/EVOH A Edwards et al Lab on a Chip 2011 45
- 46. MCF Development. Microporous MCF membranes Bore fluid PVDF/NMP (18/82 wt Die %) Haul-off Air-gap Nitrogen External Gas Coagulant Cylinder Glass Water Polymer Bath Solution Single Capillary, MCF membranes Sina Bonyadi 46
- 47. MCF Membrane Fabrication Concept Polymer Solution Bore Fluid Air-gap Water coagulation bath 47
- 48. Microporous MCFs 2 Āµm 100 Āµm 1 Āµm 2 Āµm Bonyadi et al. Journal of Membrane Sci 2012 48
- 49. Plastic Fantastic Microcapillary Films (MCFs) ā¢Polymer processing lessons learnt. ā¢A new material form looking for the right application. 49
Editor's Notes
- the precision location of each injector tip to within 10 microns.
- The high accuracy of the features within a low-voidage MCF can be attributed to a carefully designed and precision fabricated die assembly . Outer voidage = 10 % Inner voidage = 9 %
- The MCF sample was clamped in vertically to apply the load in the extrusion direction . The top clamp was set to advance at a certain speed and load was recorded by the software TA Texture Expert, running on a PC. The bottom clamp remained stationary; the initial distance between the clamps was 10 mm.
- Error bars are plus and minus one standard deviation of the mean hydraulic diameter. In this graph we can see that the hydraulic diameters of the MCF edge capillaries are bigger than the ones in the centre. The clear trend shown here is that an increase in draw corresponds to a decrease in the hydraulic diameter of the film.
- Error bars are plus and minus one standard deviation of the mean hydraulic diameter. In this graph we can see that the hydraulic diameters of the MCF edge capillaries are bigger than the ones in the centre. The clear trend shown here is that an increase in draw corresponds to a decrease in the hydraulic diameter of the film.
- In order to reduce capillary size, continuous drawing i s currently performed to hot drawn the MCF as it is extruded. In order to carry out application research in other fields, for example optical diffraction gratings, it would be necessary to make MCFs with capillaries having mean hydraulic diameters of around 700 nanometers. The first set of rollers act to quench the extruded polymer. The next roller that the extrudate is in contact with is heated to just under the melting point of the polymer, around 114C for LLDPE, with the spool roller being set at a velocity higher than the first chill roll velocity. In this way the polymer can be hot drawn, thus achieving a reduction in the dimensions of the MCF and the capillaries within it.
- It has been possible to create MCFs with capillary sizes of the order of 5 microns using a polyether urethane and if I can obtain a further reduction to below one micron, the film will create interesting and useful colour diffraction effects.
- Subsequent second stage drawing of the high voidage MCF is influenced by the orientation within the material. Axial drawing is limited to brittle fracture but large deformation transverse drawing is possible through a series of successive neck drawing from each capillary.
- The first generation of MCFs were termed ālow-voidageā MCF. These materials were characterised as having essentially uniform capillaries and voidage typically between 10 % and 15 % based on the ratio of total capillary area to total polymer cross sectional area. The low-voidage MCF product has capillary mean hydraulic diameters between 100 Ī¼m to 400 Ī¼m. It was made with a commercially available grade of linear low density polyethylene (LLDPE), manufactured by the Dow Chemical Company Inc. (Dowlex NG5056G). Alteration of process conditions can strongly influence the MCFās cross sectional geometry and the capillary mean hydraulic diameters.
- The MCF sample was clamped in vertically to apply the load in the capillary direction In the case of high-voidage MCF the initial film had orientation and the mechanical deformation behaviour was highly anisotropic The material high-voidage MCF behaved in an essentially brittle manner along the extrusion direction
- The MCF sample was clamped horizontally to be drawn in the transversal direction but by transverse drawing of the MCF a highly unusual ultra high-voidage microstructure was obtained
- In this video you can see how the HV-MCF is unfolded to form the UHV-MCF
- Front view and cross sectional view of the UHV-MCF.
- The high accuracy of the features within a low-voidage MCF can be attributed to a carefully designed and precision fabricated die assembly . Outer voidage = 10 % Inner voidage = 9 %