CHARACTERISATION OF CROSS-SECTIONAL CONFOCAL IMAGES FROM MIXED TROPICAL HARDWOOD COMMERCIAL PULP FIBRES

摘要

The conventional light microscopy is time consuming and more often involves expensive sample preparations which include the steps of embedding, sectioning and staining of the specimen. Such technique generally allows the measurement of large numbers of cells (particularly wood cells), but at poor resolutions or with limited accuracies. Recently, these limitations were overcome with via the introduction of the current technology of confocal laser scanning microscopy (CLSM) that has found wide applications in the biological sciences as well as material sciences. In this study, mixed tropical hardwood commercial pulp fibres obtained from a commercial pulp and paper mill were optically sectioned using a confocal laser scanning microscope. Cross-sectional confocal images generated under epi-fluorescent mode for unbeaten and beaten pulp fibres (using PFI mill) were processed and analysed using image analysis software. Cross-sectional dimensions such as centreline perimeter, lumen area, fibre area, lumen perimeter, fibre width and fibre thickness were determined from these images. These determined dimensions were later used in the calculation of their fibre wall thickness, aspect ratio and collapse index. In the result, typical cross-sectional confocal images of the unbeaten and beaten pulp fibres were shown with their uncollapsed lumens, and partially and fully collapsed, respectively. In general, the determined and calculated cross-sectional dimensions, i.e. centreline perimeter, lumen area, fibre area, lumen perimeter, fibre thickness, fibre wall thickness and aspect ratio were found to dwindle off with the process of beating. Statistical analysis performed showed significant differences at a significant level of 0.05 among the three levels of beating carried out onto the pulp fibres.