الفهرس يوجد فقط 14 صفحة متاحة للعرض العام
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المستخلص
1. INTRODUCTION
Cotton is a crop that has been associated with ancient civilization, greatly contributed to industrial and economical development of many countries. Its great value and desirable properties have ensured its survival as one of the world’s most widely cultivated and major cash crop, despite the stiff competition it faces from man-made fibers.
The market value of cotton is largely determined by a subjective evaluation of a limited number of quality parameters such as: Grade, Length, and Fineness.
Cotton is classed to determine its grade, which indicates the spinning value and utility, and hence the market value or price. Farmers are interested in the classification of cotton by grade to evaluate production, harvesting, and ginning practices, in order to market their cotton profitably, on the other hand, merchants could efficiently buy and sell cotton in accordance with grade.
From the spinner’s point of view, the reasonable uniformity in quality of cotton in terms of grade is essential and required to attain even-running of cotton in processing and produce yarns of satisfactory performance.
The world wide spread of High Volume Instrument (HVI) testing systems, with their ability to provide rapid and economical measurements of the most important cotton fiber properties, has stimulated efforts to obtain the maximum benefits from these systems.
Recent researches have proceeded in two directions: investigating the accuracy and reproducibility of the data obtained from these systems, and development of regression equations relating HVI properties to yarn or fabric quality parameters.
HVI measurements are in accord with the standard test methods of the American Society for Testing and Materials (ASTM). It was found that combinations of HVI measured fiber properties can account for 80 to 95% of known variation in yarn strength and 75 to 85% in fabric strength.
Development in spinning and testing technology necessitate the evaluation of a more effective method for determining the actual value of the cotton based on the value of its inherit characteristics that contribute to the quality of the yarn and textile products made from it.
The market value of the fibers should reflect the technological value of cotton and establishing such value is extremely useful for both cotton users and producers.
Its worth to say that we are in a need for the visual classification, as it is suitable for application in the local marketing system, as producers sells seed cotton. While using the fiber quality index (FQI) comes in a following step, as it is suitable for application in the international marketing system, as traders sells lint cotton.
The present investigation was conducted to demonstrate the relative contribution percentage of the HVI fiber properties to the different yarn quality parameters, besides illustrating a statistical
approach for determining the Fiber Quality Index (FQ