Influence of card to flats settings in the improvement of yarn quality Vishnu Dorugade*, R.D. Parsi and Lakhan S. Girase Spinning Department, Centre for Textile Functions, Narsee Monjee Institute of Management Studies, Mukesh Patel School of Technology Management and Engineering, Shirpur Campus, Dist. Dhule, Shirpur 425405, Maharashtra, India (Received 21 July 2012; final version received 11 September 2012) This project work deals with neps and the emphasis is given on minimizing the neps and neps size in carding for achieving good quality of yarn and fabric. The trials were conducted to justify the quality by changing the card settings (cylinder to flats and cylinder to doffer) and the improvements in resultant sliver and yarn were evaluated on AFIS and UT-3 tester. The neps content in yarn and fabric in relation with existing card sliver, which have been channelized up to yarn and knitted fabrics showed better results when compared to existing ones. After taking trials on different settings, it is found that neps and neps size reduced up to a certain extent. Keywords: card; flats; doffer; neps; seed coats Introduction Neppiness is one of the main quality problems of cot- ton yarns, especially in those designed for production of high quality fabrics for apparels. Neps contained in processed raw cotton are the neps source in yarn (Shrivasta 1991). Nevertheless, not all the neps and seed coat neps being in raw cotton are transferred to the yarn and are registered by the Uster tester as yarn faults. In any cotton mixing and its spinning process, neps are available in various sizes. A nep becomes significant or insignificant based on its size and yarn count. A nep of micrometer in size is critical for yarn quality (Joseph 2001). One of the most important cotton yarn quality parameters is the neps count per gram. Neps’ presence influences the yarn appearance, fabrics produced from it, their smoothness as well as dye evenness (Dipali 2005). The neps source in the yarn are neps contained in the raw material used for production. During the technological process, the neps number changes. Dur- ing the preliminary cotton fiber treatment in the blow room, there is an increment in the neps number (Klein 1997). It is due to the mechanical action of working elements of cleaning and opening machines and pneu- matic fiber transport. The increase in neps number during processing in the blow room depends on processing conditions like adjustment of machinery working elements, climatic conditions, pressure, rotary speed of cleaning elements as well as on fiber charac- teristics, especially the parameters which influence the fiber ’ s ability for creating neps. During carding, there is a reduction of the neps number in the web feeding the carding frame. Its amount depends on many factors – the degree of utility and cleanness of covering of main cylinder, licker-in and flats, general technical shape of machinery, cylinder rotary speed, adjustment of working elements of machines, and so on (Khare 2007). The parameter characterizing the carding machine effectiveness in the aspect of nep reduction is Nep Removing Efficiency (NRE%) which is expressed by NREcard ¼ Nfeed card À Ndeliver card Nfeed card  100: Literature review Generally in carding, there are two possible ways by which fibers can be formed into a neps. One is when a fiber or a small group of fibers are loosely caught between two surfaces moving in opposite directions (e.g. the surface of two cylinders both rotating clock- wise or counter-clockwise) or between one stationary and one moving surface (Merrill 1955). The frictional contact with the two surfaces will cause the fiber length to buckle and roll up into an entangled knot. To *Corresponding author. Email: mpstme.ctf@gmail.com The Journal of The Textile Institute, 2013 Vol. 104, No. 4, 370–374, http://dx.doi.org/10.1080/00405000.2012.734473 Copyright Ó 2013 The Textile Institute