engleski

Influence of thread fineness and warp and weft density on colour values of woven surfaces

Multicolour jacquard fabrics are mostly structurally multi-layer fabrics with patterns of various shapes and sizes, which are made of differently coloured areas. The colour in particular parts of pattern depends upon the number of differently coloured threads that interlace in the top layer of the fabric and their colour characteristics as well as upon the fabric constructional parameters - thread fineness, warp and weft threads density and weave. In practice it happens very frequently that a yarn of defined fineness is replaced by a yarn of slightly lower or higher fineness with identical colour values and with an unchanged or adequately corrected thread density. Of course this reflects in colour values of those parts of the fabric where these threads appear on surface. The colour effect of surface changes particularly in relation with other effects in the patterns. Prior to introduction of numerical evaluation of colours and equipment for optical measuring of their values it was impossible to objectively estimate colour deviations resulting from the changed yarn fineness or changed warp and weft threads density. Even today it is practically impossible to carry out a systematic research of this influence on real fabrics because it is impossible to weave such a big number of referential patterns (different types of yarn, different ranges of fineness and densities). CAD systems enable relatively quick and cost-effective preparation of simulations of colour surfaces of multicolour patterns. They even enable changing of certain parameters within the ranges, which can be hardly or cannot be achieved at all in practice. By the measurements carried out on these simulations colour deviations due to the changed yarn fineness or warp and weft density can be estimated in a wider interval. It has to be emphasized that there is a difference between the measurements carried out on colour simulations and on real fabrics. However, the aim of the research is to determine the principles and above all to estimate quantitatively the influence of the changed yarn fineness and warp and weft density on colour values of a fabric simulation. In further researches it would be possible to prepare only a defined number of real fabrics and to compare the results on simulations. The paper presents the simulations of a defined number of fabrics of different fineness, the results of their colour values measurements and the analysis of their differences.

fabric simulation; thread fineness; thread density; colour values measurements

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