Changing the Method of Cotton Quality Evaluation
March 31, 2010 Cotton quality evaluation has always been an important element of the world cotton trade. But growing expectations in the industry have led to even greater emphasis on solid cotton classification. This is especially important to the final recipients of this raw material: the spinners.
Not a very long time ago, cotton producers and merchants were satisfied with the knowledge of commercial quality parameters such as color and leaf grades, micronaire, and staple length. Cotton exchanges, e-commerce and price indices also are based only on these basic quality factors. Spinners’ expectations related to the technological advancement of textile production are much greater, however. They need to know additional fiber parameters such as breaking strength, maturity, linear density, length non-uniformity, short fiber index, neps and dusts content. These types of analyses are only possible with instrumental methods, through the use of HVI, AFIS and other systems.
Last year brought a considerable development and popularization of instrumental cotton quality evaluation methods. It has been estimated that there are about 2,200 Uster HVI lines functioning in the world and about 400 Premier apparatuses in use. All of these class about half of the world cotton crop, according to International Cotton Advisory Committee (ICAC) data. Despite the constant growth in the number of cotton tests being performed with instrumental methods, half of the world crop is still classed manually – by comparing the fiber to standards of individual cotton producers.
The Commercial Standardization of Instrument Testing of Cotton (CSITC) Panel – acting since 2003 on the ICAC forum – plays a special role in the popularization of the instrumental method, mainly in adapting it to the reality of the contemporary cotton trade. An important element of maintaining the highest possible level of cotton tests are Round Trials which have been organized by CSITC for more than three years.
Round Trials include about 90 participating laboratories from all over the world. Implementation of the instrumental method on a large scale around in the world certainly makes the classification activities more efficient, but it does not eliminate man and his knowledge from this process. To be sure, one of the conditions of receiving correct test results is proper qualification of the operator responsible for carrying out the tests.
A part of HVI results may be burdened with errors. This pertains to important “commercial” cotton fiber parameters and mainly to cotton leaf grade. That is why the results received with instrumental method should be verified by persons who have a profound knowledge of the raw material and who are able to class the fiber independently – by themselves.
For more than 50 years, the Gdynia Cotton Association of Poland has been one of the three institutions in the world organizing the full-time Cotton Classification Courses. Since 1948, the course has graduated over 600 persons from 28 countries, representing government institutions, trading companies, industry, and superintendence organizations.
Thanks to the “practical training” focus of the course syllabus, the participants acquire or improve their skills of cotton classification. Moreover, students receive a considerable volume of knowledge about the world cotton market, transportation and handling of cotton (warehousing, weighing, sampling, etc.). Lately, the program of laboratory classes has been broadened by the issues related to HVI testing. Our course graduates are able to properly interpret the results received from the HVI, to trace errors committed by HVI (in the scope of leaf grade or color, for instance) and to react to them properly.
The frame program of the course encompasses: manual cotton classification; laboratory methods of cotton classification, with particular attention paid to HVI; cotton standardization according to Universal Cotton Standards, which is the basis for instrumental system of cotton evaluation; and description of selected problems of world cotton markets, cotton trade, transportation and handling as well as calculation of claims for fiber worse than that in the contract.
The full program of the course takes six weeks to complete, but both the program and its duration may be shortened and adapted to the needs of a defined group of participants.
photo:
Andrzej Drozdz
GET THE NEWSLETTER TODAY!
