Assessment of reflectance index of selected vegetable fibres

Colour is an important factor in the evaluation of aesthetic appearance and functionality of many products especially in textiles. Nature has given colour to the fibres which are obtained from different vegetable sources depending on the origin and other geographical factors. Natural fibre yielding plants are abundantly available in our country. The non edible portion of these plants should be rightly used for various purposes. For this reason, the selected fibres were processed to obtain the required properties and to remove the adherence of unnecessary materials from it. The purpose of the study is to identify the effect of scouring and bleaching on the tristimulus values for brightness, whiteness and yellowness indices. The instrument spectrophotometer was used to analyse the selected vegetable fibres namely areca nut, aloevera, banana, coir, hemp, jute, korai and sisal at raw state, and after scouring and bleaching processes. The degree of whiteness, yellowness and brightness between the fibre samples has been assessed. A comparison was made between the visual evaluations made by observers and spectrophotometric analyses. The tristimulus values of the indices varied between the fibres in raw state as the selected fibres had self colour on their own. After scouring and bleaching also these values varied. It is also observed that all the Y values are positive depicting the yellowish shade as the negative Y values express a bluish shade in the fibres. From the spectrophotometric analysis it was understood that the yellowness was predominant in few fibre samples. In the jute and sisal bleached samples the spectrophotometer analysis is in par with the visual evaluation. Statistical analyses also support the study with 1% significant difference among the fibre samples between the tristimulus values and the indices among fibres.