Introduction
Analysing cellulose nanofibre morphology
Fibre analysis tools in nanocellulose literature
Publication type | Number of publications | Description |
---|---|---|
Characterisation | 104 | General characterisation of nanofibre pulp morphology |
Setpoint measurement | 11 | Fibre morphology used to determine when a refining setpoint has been reached |
Commentary | 4 | Commentary about the use of MorFi as a fibre analysis tool |
Review | 3 | Comparative review of different fibre analysis tools |
Detailed characterisation | 2 | Detailed characterisation of nanofibre pulp morphology |
Integrated characterisation | 2 | Characterisation of nanofibre pulp morphology, Integrated with other nanofibre characterisation tools |
Methodology | 1 | Discussion around the methodology for conducting MorFi analysis |
Predicting nanopaper quality
Experimental methodology
Materials
Biomass preparation & CNF production
High pressure homogenisation
Fibre morphology analysis
Code | Parameter | Unit | Description |
---|---|---|---|
Fibre_n | Number of analysed fibres | – | The total number of fibres analysed throughout the test |
Fibre_cont | Fibre content | Millions/g of pulp | The number of fibres (millions) per gram of sample analysed |
Fibre_L | Mean arithmetic length | µm | Arithmetic mean length of all fibres analysed |
Fibre_L.L | Mean length-weighted length | µm | Arithmetic mean length of all fibres analysed, weighted by fibre length |
Fibre_L3.L | Mean cubic-length-weighted length | µm | Arithmetic mean length of all fibres analysed, weighted by the cube of the fibre length |
Fibre_A.L | Mean area-weighted length | µm | Arithmetic mean length of all fibres analysed, weighted by fibre area |
Fibre_W | Mean fibre width | µm | Arithmetic mean width of all fibres analysed |
Fibre_coarse | Mean fibre coarseness. mg/m | mg/m | Fiber mass per unit length |
Fibre_kink.num | Mean kink number | – | The number of fibres with small regions of very high curvature (i.e. sharp bends) along the fiber |
Fibre_kink.ang | Mean kink angle | The mean kink angle for fibres that are kinked | |
Fibre_kink.cont | Kinked fibre content | % | The number percentage of fibres with a kinked structure |
Fibre_curl | Mean fibre curl index | % | Degree of nonstraightness of a fiber—or the ratio of total particle length over the projected length |
MF.index | MacroFibrillation index | % | Percentage of microfibrils by area |
Fibre_broken | Broken fibre content | % | Number percentage of fibres with broken ends |
Fine_n | Number of analysed fines | – | The total number of fibres analysed throughout the test |
Fine_cont | Fine content | Millions/g of pulp | The number of fines (millions) per gram of sample analysed |
Fine_cont.A | Fine content | % (in area) | % Area of Fine Elements over all other elements |
Fine_cont.L | Fine content | % (in length) | % Length of Fine Elements over all other elements |
Fine_cont.L.L | Fine content | % (in length-weighted length) | % Length weighted length of Fine Elements over all other elements |
Fine_A | Mean fine area | µm2 | Arithmetic mean fine area |
Fine_L | Mean fine length | µm | Arithmetic mean fine length |
Nanopaper mechanical properties
Statistical methodology
Correlation analysis
Principal component analysis
Regression modelling
Model validation
Energy Level | Notation | HPH Passes |
---|---|---|
Low-Low | LL | 200 bar |
Low | L | 200 bar + 400 bar |
Low-Medium | LM | 200 bar + 400 bar + 550 bar |
Medium | M | 200 bar + 400 bar + 550 bar + 700 bar |
Medium–High | MH | 200 bar + 400 bar + 550 bar + 700 bar + 1 × 1100 bar |
High | H | 200 bar + 400 bar + 550 bar + 700 bar + 2 × 1100 bar |
High-High | HH | 200 bar + 400 bar + 550 bar + 700 bar + 3 × 1100 bar |
Results
Fibre Morphology Correlations
Principal component analysis (PCA)
Nanopaper regression models
Nanopaper Metrics | MLR model | SVR model | ||
---|---|---|---|---|
NRMSE | R2 | NRMSE | R2 | |
Tensile Index | 0.4 | 0.89 | 0.23 | 0.99 |
Toughness | 0.4 | 0.88 | 0.28 | 0.98 |
Strain at break | 0.51 | 0.8 | 0.33 | 0.98 |
Young’s modulus | 0.31 | 0.93 | 0.13 | 0.99 |
NRSME | Nanopaper Metrics | |||||||
---|---|---|---|---|---|---|---|---|
Young’s Modulus | Strain | Tensile Index | Toughness | |||||
Model | MLR | SVR | MLR | SVR | MLR | SVR | MLR | SVR |
Low | 1.49 | 0.80 | 2.57 | 0.93 | 2.18 | 0.63 | 1.23 | 0.53 |
Medium | 1.19 | 0.48 | 1.43 | 0.97 | 1.16 | 0.56 | 1.71 | 0.87 |
High | 0.67 | 0.44 | 2.15 | 0.87 | 1.35 | 0.44 | 2.35 | 0.79 |
Validation of model predictions
Validation Series Outputs | Nanopaper Metrics | |||
---|---|---|---|---|
Young’s Modulus | Strain | Tensile Index | Toughness | |
MLR NRMSE | 1.70 | 2.42 | 1.62 | 2.14 |
SVR NRMSE | 0.81 | 1.86 | 1.72 | 1.95 |