The development of new colour communication system for shade sorting and colour acceptance determination

Over the past few years, the value-added textiles like dyed and printed fabrics occupy a major share of the textile export all over the world. Since the overseas buyers are conscious of the consistency of colour, the exporting companies are now starting to realise the importance of colour communication system (C.C.S) which can be used to predict the complicated shade variation between different lots or within the same lot.; The work described in this thesis aim to provide a fundamental understanding about the colour acceptance determination and shade sorting system. Several advanced methods have been developed to carry out such processes with reference to some statistical computational techniques. 1500 coloured samples have been produced from the dyeing of cotton knitted fabric with 20 different combinations of dyeing recipes.; The instrument used for the colorimetric data gathering has been studied thoroughly including its capability and reliability. Parts of the colorimetric data obtained were chosen for the preliminary shade sorting process with the aid of 555 and Clemson Colour Clustering (CCC) shade sorting methods. The purposes of this preliminary test are to study the capability of the software available for shade sorting and the effectiveness of the two shade sorting processes. CCC shade sorting process has been confirmed to be a more effective method when compared with the 555 shade sorting process. The results confirmed that the whole direction of this research was based on the proceeding of CCC shade sorting process.; The best fit mathematical model used in regression analysis has been derived for describing the relationship between the instrumental assessment and visual assessment of colour variation. Furthermore, the performance of the existing colour difference formulae applied to the textile and apparel industry has been evaluated to obtain the best fit one for the colour quality control process, and to generate the most uniform colour space/microspace for shade sorting. The standardised permissible colour difference tolerances were established for the colour acceptance determination and shade sorting systems for further investigation of shade passing and shade sorting.; The reliability of the existing shade sorting systems applied to the textile and apparel industry was analysed after the successful standardisation of shade difference tolerances. The results have led to the study of the modification of CCC shade sorting process by combining the hierarchical and non-hierarchical algorithm into a single process. The performance of such modification of the CCC shade sorting system was found to improve significantly.; A new shade sorting system called Newly Developed (ND) shade sorting has been developed using hierarchical clustering technique. The results showed that it could offer a further improvement in shade sorting performance. Further refinement to the ND system by combining the hierarchical and non-hierarchical algorithm into a single process is resulted in Refined Newly Developed (RND) shade sorting which is considered as the best shade sorting system used for solving the discrepancy of colour problem in the textile and apparel industry.