When considering yarn production from the economical point, it is advisable to use medium volume instruments (MVI) and low volume instrument (LVI) to achieve the same quality with medium cost, says V. Parthasarathi.

The global spinning industry is currently undergoing big changes, not least to wards the use of more modem and faster spinning machinery and computer system. These high speed machines require much cleaner raw material, and therefore they constantly challenge the testing machinery developers to provide faster and more accurate testers and quality controllers. The techniques de cribed in this article are mainly related with colton fibre testing.

In this article, the author has dealt with the following:

• Concepts in bale management
• Latest fibre testing instrument
• Principle of fibre testing using HVI
• Advanced fibres information system (AFIS)
• Fibre contamination system (FCS)
• Integrated indices for fibre quality
• Different methods of maturity measurement
• Image analysis
• Different methods of fineness measurement
• Advantageous of latest fibre testing

In this, HVI, AFIS & FCT play an important role, so their principle working method, working time and sample requirements are given. It gives various new technologies employed in printing, which will give an idea about the new testing methods and procedures.

Machine speeds and settings need to be matched to the properties of the fibre in process. With the annual production of cotton lint approaching 100 million bales, with spinner's demands & for increasingly high quality, and with the testing of every bale becoming almost universal in export mills, cotton testing has never been more important.

The following observations have made the cotton testing an important one.

The following observations have made the cotton testing an important one:

• Raw material typically accounts for half of the cost of making cotton yarn.
• Competitive man-made fibres can be made to more precise specifications.
• Scientific blending, based on knowledge of each bale, leads to cost & quality effective processing.
• Machine speeds and settings need to be matched to the properties of the fibre in process.
• Demands on the yarn quality are increasing.

Concepts in bale management

This is based on the categorising of cotton bales according to their fibre quality characteristics. It includes the measurement of the fibre characteristics with reference to each individual bale, separation of bales into classes and lying down of balanced bale mixes based on these classes. The reason for undertaking this work lies in the fact that there is sometimes a considerable variation in the fibre characteristics from one bale to another, even within the same delivery. This variation will result in the yarn quality variation if the bales are mixed in an uncontrolled manner.

Latest fibre testing instruments

Latest trend in the fibre testing was the developments of a single instrument in which all the major testing parameters can be tested. The instruments we discuss in this category are:

• High volume instrument (HVI)

• Advanced fibre information system (AFIS)
• Fibre contamination tester (FCT)