Development of reflectance intensity based microcontroller for fibre compactness analysis

Abstract

Quality is an integral element in human life. All industries ranging from medical, electronic, automotive, aviation, textile, food, to wood and paper possess some sort of quality control element in both the output and manufacturing process. Surface quality measurement is a process in the industry to investigate the surface of a material. One method in determining the surface quality is by measuring its fibre compactness and arrangement. Currently, equipments used to examine the fibre compactness and arrangement on the surface of a material includes optical microscope, VIS/NIR spectrophotometer, scanning electron microscope (SEM) and transmission electron microscope (TEM). However, all of these equipments are costly. Therefore, there is a need for a simple and cheap method to quickly determine the surface quality of products before it is marketed to consumers. In this research, a simple, low cost prototype of microcontroller to measure reflectance intensity were designed and fabricated to differentiate various fibre arrangement and compactness by using laser and principle of reflection. The signal detected by photodiodes was converted into a voltage which can then be correlated with the surface quality of the sample. The scope of this project focused on the differentiation of high and low density paper. The prototype was tested on high density paper, represented by 70 g/m², 80 g/m², and 100 g/m² common printing paper and low density paper, represented by three, two and one ply facial tissue paper. Measurement results showed that 100 g/m² printing paper exhibited a higher reflected voltage output compared to 80 g/m² and 70 g/m² printing papers. This is because the denser fibre arrangement in the higher density paper results in higher reflectance intensity. As for the low density papers, results showed that the number of ply of the tissue paper significantly influences the light reflectivity. The high density tissue paper with a higher number of ply showed higher voltage output compared to lower ply tissue paper. Microscope observation method supports the reflectance analysis. Measurement done by UV lambda 950 spectrophotometer produce similar observations, hence validate the reflectance analysis. From this research, it was found that the prototype able to successfully differentiate various fibre arrangement and compactness on several material surfaces using surface reflection. This prototype has the potential to be further extended its usage to other fibre materials.