Course Title: Project Work

Prepared By:FAHIM ASHAB KHAN – 070032

MD. SHAHID - UL - ALAM – 070059SAEED MOHAMMAD ZAKIR - 070070

No. of fiber in yarn cross section of different count and their fineness (micronaire value).

Find the strength of those yarn in respect of no. of fiber in the cross section

We were very fortunate to carry out our Project Work. So, at this point we would like to express our gratitude to everyone related. We are highly indebted to the Pabna Textile Engineering College authority for their whole hearted cooperation cordial support in providing information and assisting our Project related activities. Especially we would like to thanks, Mr. Ahmed Ali, Chief Instructor, Yarn Manufacturing Department. For give us chance to Complete the project . Then all our heartiest thanks who gives us logical guideline, constant inspiration and proper supervision of this College. Then we would like to thanks, who is very helpful person to give us various types of information. We are really glad and happy for supervising our project in a systematic schedule and all sorts of help. At last we apologize to all teachers, staffs and technicians of Pabna Textile Engineering College, whose name is not mentioned here but who have helped us to overcome different problems in different situation and of course without their support our training could not come out with success.

o To know about the no. of fiber in yarn cross section.oTo determine the micronaire value of consisting fiber.oTo measure the strength of yarn of different count.oTo analysis the change in strength of yarn in respect of no of fiber in yarn diameter .oTo analysis the change in no of fiber in yarn diameter in respect of micronaire value .

This project will help us to get better knowledge about yarn evenness and also we can ensure the required strength. From the experiment of this project some yarn characteristics like Strength, MIC, Evenness can be determined easily. We can compare the yarn of different count in respect of no. of fiber in yarn diameter. The fibre maturity through the yarn length can be assumed in standard scale by comparing no. of fibre in cross section and strength in every specimen of yarn.

Fineness is one of the three most important fibre characteristics.The fineness determines how many fibres are present in the cross section of a yarn of given thickness.Additional fibres in the cross section provide not only additional strength but also a better distribution in the yarn.Thirty fibres are needed at the minimum in the yarn cross section,but there are usually over 100.one hundred is approximately the lower limit for almost all new spinning process.This indicates that fineness will become still more important in the future.Fibre fineness primarily influences spinning limit;drape of the fabric product; yarn strength; lusture; yarn evenness; handle; productivity.

Fineness is usually specified by the relation of mass to length.The micronaire value is used worldwide for cotton.it’s easier to produce more finer yarn with the decreasing of mic of the fibre.So, it’s too much essential to know about the micronaire value.This paper represent the yarn strength based on the yarn fineness.As the cotton sample of variance fineness has different no of fibre in cross section so they will give a different strength. For a given yarn count, yarns with better evenness and strength are more easily produced from finer fibres as the yarn cross-section can then contain more fibres than an equivalent yarn constructed from coarser fibres. The physical model for yarn evenness and strength can be discussed in more detail in a subsequent steps but for the moment it is important to remember that both yarn count (how fine) and yarn quality (how even and strong) are the main reasons why fibre fineness is so important, and thus why spinners prefer to purchase fibres with a specified fineness.

But without an accurate measure of fibre fineness the spinning industry is forced to adopt a risk minimisation strategy by choosing cottons within a relatively narrow micronaire band. Within these bands the spinner can be reasonably assured that the fineness and maturity of the fibre will translate into good quality yarn.

Micronaire value, strength, fineness, quality, evenness.

Cotton is a cultured, natural product and is always referred as a non-homogeneous raw material. It exhibits variation from fibre to fibre, bale to bale, area to area, and season to season due to climatic conditions, growing areas and harvesting methods etc. Quality parameters of yarn fibre length and fineness, no. of fibre in cross section have a vital influence upon the ultimate yarn strength. Fibre strength determines the amount by which fibres can overlap with one another, greater the overlapping; the easier it would be for the fibres to bound together and better would be yarn strength. This means that no. of fibre in yarn cross section have a direct influence on yarn strength and could be negatively affected by shorter span length.

Fibre fineness is another important fibre character affecting yarn strength. It gives number of fibres in the cross-section of yarn. Better the fineness of cotton, more would be the number of fibres per cross-section resulting in higher yarn strength. When other characteristics are same, fine fibres will produce a yarn of higher strength than coarse fibres.

Cotton count•Cotton Counts: The number of hanks of 840 yds in one pound of weight i.e. 10 count cotton means that 10x840 yds weighs = 1 lb. This is coarser than 40 count cotton where 40x840 yards are needed. In the United Kingdom, ones to 40s are coarse counts (Oldham Counts), 40 to 80s are medium counts and above 80 is a fine count. In the United States ones to 20s are coarse counts.•Hank: A length of 7 leas or 840 yards

Micronaire Value:Micronaire is a unit of fibre fineness which is expressed in fibre weight in microgram in an inch. The commercial trade relies on micronaire readings to indicate the fineness of cotton, despite it being well known that the micronaire reading represents a combination of fibre fineness and maturity, and as a result is not a particularly accurate measure of either important parameter. As the needs of spinners become more sophisticated, micronaire will increasingly fail to provide adequate information.

The fineness scale is as follows:

Micronaire Value(µgm/inch) Fineness Up to 3.1 very fine 3.1-3.9 fine 4.0-4.9 medium 5.0-5.9 slightly coarse Above 6.0 coarse

We can find a relationship with fibre fineness,no of fibre in cross section and irregularity which has been metioned as follows : The finer The higher the number of fibre in yarn cross section Fibre  

Reduce the yarn irregularity The greater the total surface are available for interFibre contact to provide the necessary cohesion + Less twist required.

STRENGTH : Toughness of fibre has a direct effect on yarn & fabric strength. Fibre strength Yarn & fabric strength

Strength is very often the dominating characteristics. The minimum strength for a textile fibre is approximately 6cN/tex ( about 6 KM breaking length. ) . In relation to cotton , the strength of fibre bundle is measured and state as the pressley index.

The pressley index = Breaking load in lbs / bundle wt. in mg

The following scale of the values are used :93 and above - Excellent

87 to 92 - Very strong81 to 86 - strong

75 to 80 - medium strong70 to 74 - fair strong

Below 70 - weak

We know that ,

No. of fibres in cross section (N) = yarn count in tex (Ntex) / fibre count in tex

Or, N=Ntex / {(mic x106) / (106 x 25.4)} Or, Mic = (Ntex x 25.4) / N …(1) When , yarn count =NeSo , yarn count in tex = 590.5 / Ne Here , Mic = fibre count in tex

Three bobbins of yarn having 32, 30, 24 Count are taken to done this project. Then the yarns from every bobbin has been cut into three specimen where every specimen has around 12 yds of yarn. Every end of specimen being untwisted by hand process to determine the no of fibre of every specimen’s cross section carefully. Then the readings were listed in the table .Then average no. of fibre in cross section (N) are calculated. Now , to calculate the micronaire value for every specimen we use the above equation no. 1 by collecting the required terms (Ntex , N). then the readings were listed in the table .

Then average micronaire value is calculated . strength of every specimen has been measured and listed in the table 2.

The average strength of respective count is determined and listed in the table 2.

Then the resulting strength is multiplied with respective count to determine the Count Strength Product (CSP) .

Table

Count No. of specimen

No. of fibre in cross section

Avg. no of fibre

MIC Avg. MIC

Strength

Avg. strength

C.S.P

32 1 117 111 4.00

4.25

78.51

78.59 25152 112 4.19 78.633 102 4.58 78.47

30 4 122 119 4.11

4.09

85.70

85.73 25725 118 3.9 85.976 116 4.28 85.62

24 7 160 142 3.9

4.33

109.125 108.7

92613

8 138 4.5 108.839 130 4.59 108.66

7

RESULTS :

From the above table , we get

Count No. of fibre in cross section MIC Strength CSP 32 111 4.25 78.59 2515 30 119 4.09 85.73 2572 24 142 4.33 108.87 2613

By analyzing the above experiment , we have taken the following decision –

The no. of fibre in cross section of the yarn is inversely proportional to the micronaire value.

Yarn strength is inversely proportional to the micronaire value. 

In short MIC No. of fibre in cross section CSP Strength

By analyzing the experiment we have got the following graphs.

1. MIC vs No of fiber for definite count.2. Strength vs No of fiber for definite count

MIC No. of fibre in cross sectionFor 32 Count

No. of fibre in cross section strength For 32 Count

MIC No. of fibre in cross section In Particular count

Yarn quality and processing performance in a spinning mill is of utmost importance and is determined by a number of factors. Predominant of these is the number of fibre in the cross section of a yarn, determined by the fineness of the cotton fiber being used.

The recent high micronaire values have become a concern to spinners as this means that higher quality fine,and lower quality is coarse. Which means that spinners are forced to source what they require elsewhere.

It is well known and documented that micronaire is a combination of maturity and fineness, and that by itself the micronaire value is unable to properly distinguish premium fine mature cotton from immature, coarser cotton. While there are already a number of methods for measuring fiber maturity and fineness, no one method is able to do so accurately and with the speed requirement for classing purposes.

The development of fiber fineness, fiber maturity,fibre strength, no of fiber in cross section, merchants and spinners alike to manage fiberfineness and maturity.