Theproperties of yarn are influenced by a number of factors, among themthe particular specifications, the parameters of operation and thefibre properties. In respect to the fibre properties, the leading andperhaps the factor carrying the highest potential in terms ofinfluence is the mean diameter of the fibre. Other equally importantfeatures of the fibre are the length, the strength of the fibre andhow the diameter of the fibre is distributed. These factors areinstrumental in influencing the properties of the yarns as well asthe spinning performance. As previously anticipated, the nature ofhow the distribution of the length of the fibre has been found to bevery instrumental. When considering the spinning performance as wellas the properties, the twist and linear density are two factors thatmust not be ignored. To obtain the maximum strength of a yarn, thetwist level is expected to be increased. However, if the twist levelgoes beyond the maximum, the yarn commences to become weak. Thelinear density of yarns is also critical in that any irregularitydirectly affects the strength as some areas become either weak orthinner than it ought to be. To measure the properties and spinningperformance of yarns, traveller weight, the size of the ring and therate of spinning are main parameters to be used. In regards to thesethree factors, a small ring size contributes to the traveller beinglighter and consequently, the speed of spinning reduces. The qualityof yarns is dependent on how they are processed as well as the rawmaterials used.
Dueto the existence of many independent variables, it becomesproblematic to explore all the parameters, with the capacity toeither extrapolate or interpolate the outcomes of the experiments andalso considering the independent variables, not leaving out theinteractive contribution among them. As a result, it becomes hard tocome up with a common universal theoretical or empirical model, whichcan be used to predict the spinning performance and the yarnproperties based on various mills. Various packages have been createdwith an aim of using them as parameters to gauge the spinningperformance and yarn properties for the varying fibre and conditionsof processing. One of such packages is SirolanYarnspec, whichintegrates the algorithms and theories obtained from fits. Theprogram, developed by CSIRO, predicts the spinning performance andthe yarn properties obtained as a result, thus making it an importanttool for bench-marking. The prediction is made when the mill operatesat a globally acceptable manner. The differences which exist amongthe various instruments, their test speed and the various assumptionsthat they make gunners up to eventually distort the accuracy of theempirical models. However, the shortcomings can be utilized to comeup with an effective mill model. Important to note, the empiricalmodel can be made obsolete by the changing differences which existamong various mills as well as the ever changing materials andprocesses. In regards to the constant changes, it is quite importantfor a mill model to be developed. This way, it is likely to keep upwith the changes in the use of dynamic materials and processes. Theimprovement witnessed the evenness of yarns clearly illustrates whythe development of mill specific model is important.