EXAMINATION OF THE FIBER PROPERTIES ON YARN NEPPINESS AND EXPERIMENTAL
STUDY IN A TURKISH SPINNING MILL
Ozcelik G., Kirtay E.
Ege University Textile Engineering Department
One of the basic factors influencing the manufacture of good yarn is the correct blend composition to obtain the required yarn properties. There is a direct correlation between the quality of raw materials and the end products. In order to produce high-quality cotton yarns that will produce high-quality woven and knitted fabrics, emphasis needs to be given on the quality and processing of cotton lint.
Neps in cotton lint, defined as a small knot of entangled and unorganized fibers cause formation of short, thick places in yarns and therefore less uniform fabric appearance, see Figure 1. Their presence in yarns or fabrics greatly detracts from the quality and value of the
finished cotton product [ 1].
The sources of neps in a yarn are neps and trashes contained in a fiber stream, from which directly the yarn is formed. The number of neps in cotton yarn depends on two main factors:
- Characteristics of raw material used for the yarn production
- Conditions of the technological process in the spinning mill. [2]
The objective of the study is to determine the important raw material properties for the yarn neppiness. For this purposse 30 cotton blends have been chosen from a Turkish spinning mill and cotton properties have been determined by using AFIS (Advanced Fiber Information System) and HVI 900. In the carded spinning system, by calculating neps removal efficiency of the production machines, changing of neps and seed coat neps counts during yarn production is determined.
From the cotton blends yarns, of which counts vary between Ne18 and Ne36 were produced. Thanks to the fiber and yarn properties, for prediction of the yarn neps from fiber properties, by means of multiple regression analysis, the regression equations have been obtained. Regression analysis have done according to enter and stepwise methods. The reason of using stepwise method is to state precisely the most important fiber properties that influence the yarn neps formation. In the following, first the employed fiber properties,
measured by HVI and AFIS instruments for the regression analysis is given, see Table 1. As yarn lineer density plays an important role for the registiration of yarn neps in the measuring device, yarn count has been also included in the regression equations. The derived regression equations can be seen in Table 2.
As it can be seen from Table 2, for the prediction of the yarn neppiness by means of the fiber properties obtained from HVI and AFIS instruments, totally seven regression equations have been determined. Analysis of the regression equations confirms the most important
property is the yarn count. The other important fiber properties that influence yarn neppiness have been found as uniformity index, maturity and short fiber content.
