Degree of thickening, usually defined as the cross sectional area divided by the area of a circle having the same perimetre as the fibre. A double compression instrument, where estimates of linear density and maturity depend on small differences between airflow properties measured at two level of compression. It showed the effect of varying sample mass necessary for automated HVI lines and found drift in the micromat rather than the step changes of earlier models.

Different methods of fineness measurement

Direct measurements of mass divided by length, the later is the limiting factor in accuracy; this has been developed by image analysis, where it is commonly expressed as cross-sectional wall area. Measurement of resistance to airflow, by single or double compression

Advantages of latest fibre testing techniques:

• The results are practically independently of the operator.
• The tests are based on the large volume of samples and so they are more significant.
• The results are summarised and are immediately available.
• The raw material data is utilised in the best manner.
• As a result of the fibre material, the problems can be predicted and corrective measures taken before such problems can occur.

Future needs

Attempts are being made to express fibre quality by a single index. As the number of properties tested in HV lines continues to increase, so too, does the average person's confusion about the meaning of results.

They;

• Cannot tell readers the relative importance of properties for their own circumstances.
• Do not distinguish fully between the different measures of the same property, such as uniformity index and uniformity ratio.
• Do not address the diversity of ways of measuring some properties, such as maturity or measuring some properties, such as maturity or stickiness, and the different results obtained from different instruments or techniques.
• FCT is used at the gin as a quality controller and immediate cotton classing tool.

The traditional test of counting neps is so labor intensive and subjective that it invites innovation; the first step alone, is to prepare a card web, for which few laboratories have the machinery. A major response has been the development of the NEP module, AFIS-N, of the Advanced Fibre Information System.

As the fibres are separated aerodynamically then passed across a photocell, the electro-optical sensor distinguishes the wave forms of single fibres, trash and neps. Whether the sugar is metabolic or entomological and whether the secretion is from white fly or aphids matters little to the person trying to process sticky cotton.

Model liquid chromatography makes it possible to separate characterise and quantify the sugars. The sensitivity of rotor spinning to accumulations of trash and dust are led to the development of more sensitive instruments for testing small impurities in sliver. The AFIS apparatus lends itself to measurement of trash, dust and neps from lint through the roving stages and provides the entire size distribution.

Conclusion

The above discussion gives an idea about main latest fibre testing techniques using HVI, AFIS, FCT and this concludes that one can achieve higher accuracy with least time in this system. Fibre testing is an important part in the final product, so it is clear one can achieve great quality with accurate testing techniques, which were discussed in this paper. Apart from this, various methods are also included which will give proper results in fibre testing.

When considering from economical point, it advisable to u medium volume instruments (M\ & low volume instrument (LVI) to achieve the same quality with medium cost. With present depression in textile field, it is essential to achieve good quality raw material by good testing techniques and achieve good growth in textile field. It is essential in this competitive global market survival with this latest fibre testing techniques.