PSG POLYTECHNIC COLLEGE

Presentation on

LATEST DEVELOPMENT IN YARN EVENNESS TESTING MACHINE

presented by

T.S.R. praveen (14T025) k. rubini (15TH05)

TOPIC COVERED• What is yarn evenness test?

• Usage of yarn evenness tester machine .

• Working principle.

• Classification of variation.

• Latest development.

• Advantages & Disadvantages.

• Quality parameters .

• Spectrogram representation

What is yarn evenness test?

• The instrument by which the evenness (u%),co-efficient of variation mass (CVm%) yarn hairiness , imperfection index (IPI)and thick and thin place neps of yarn ,roving , sliver can be measured or calculated is called evenness test.

• The mass variations or weight per unit length variations are recorded and printed as diagram .

• It provides the wavelength spectrum, u%value and the imperfection .

Usage of yarn evenness testing machine

• Evenness measurement of yarn , roving and sliver• Measurement of imperfection (thick,thin

places,neps)• Yarn hairiness measurement .• Variation of trend analysis• Mass analysis• Spectrogram analysis/frequency analysis• Fabric simulation i.e before making fabric .

CLASSIFICATION OF VARIATION

• There are two types of variation and they area) Random variation b) Periodic variation

Random variation :Random variation is the variation which occur

Randomly in the textile material without any order.periodic variation:

Some traces show definite sequences of thick and thin places in these forms of irregularity are called as periodic variation.

Variation in weight per inch

Wavelength and amplitude

Short ,medium and long term variations

• If wave length of the periodic variation is• 1 to 10 times the fibre length it is called as

short term variation • 10 to 100 time the fibre length it is called as

medium term variation .• 100 to 1000 times the fibre length and above

it is called as long term variation.

Methods of measuring yarn evenness.

• In fact to measuring irregularity ,many methods are available involving from no equipment to electronic instruments . Of all these are to see,

1. Visual examination methods: Using black boards ,drums ,photographic device , lap meter2.Cutting and weighing methods:

Lap scale lapmeter , sliver , roving, and yarn wrapping3.Electronic capacitance testers:

Uster evenness tester Photoelectric testers:

WIRA Photoelectric testers ,LINRA tester

Latest development in yarn evenness tester machine

• Uster evenness tester is latest machine •

About uster tester machine

• To ensure every important quality characteristic can be measured accurately, the USTER® TESTER 5 range of sensor options includes both optical and capacitive technology. This combination is currently the only way to monitor and control increasingly complex yarn properties. The proven capacitive measuring method is key to the USTER® TESTER 5 ’s highly accurate control of mass variations in yarns, rovings and slivers.

• The optical sensor options, for hairiness, measure all relevant yarn parameters for a complete yarn specification or process management in the mill.

Working principle of uster machine

Raw material as well as spinning problem can be detected by the measurement of yarn evenness which is done by uster evenness tester .Main principle: Capacitance principle.

The quality parameter is determined by a capacitive sensor. In the case the yarn ,roving,or sliver is passed through the electric

field of a measuring capacitor .mass variation of the material causes the diturbance of the electric field which are converted

into electrical signal .which proportional to mass the mass variation of the material .the unevenness is recorded as diagram

The characteristic features of uster evenness tester

1. The comb of eight measuring capacitor of different sizes. The portion is called as the measuring head according to the type of material to be tested any slot can be selected out of the eight measuring capacitors .

2. Creel and guides: These are to hold the package of material and to guide them into the correct position into the slot.3.Traverse rollers : these roller can control the speed of the material passing over a range from 2 to 400 meters/min set with a switch

4. Control switches for direct evaluation

5. Momentary variation indicating meter on the main unit

6. The integrator which indicates the pmd or cv%

Uster statistics

• The uster statistics as quality reference figures which permit a classification of fibre , sliver, roving and yarn with regard to world production .

• -50 thick places• +50 thin places• 200 neps

Uster u% for carded cotton Count

good Average Below average

20S

30S

40S

50S

60S

80S

18.0 and below

20.5 and below

21.1 and below

18.0 and below

19.0 and below

20.0 and below

18.1-19.2

20.6 – 22.0

21.2 – 22.5

18.1 – 19.8

19.1 – 20.5

20.1 – 22.0

19.3 and above

22.1 and above

22.6 and above

19.9 and above

20.5 and above

22.1 and above

Quality parameters • New Raw Material for Roving • The following raw materials are new for the roving chapter: • 100% CO, compact, combed • 100% PS, ring • 100% CV, ring

Advantages

• The CV% measured by Uster give a measure of variation of weight per unit length.

• This instrument measure the irregularity of material at high speed (2-100ft/min)

• It can show both % of M.D & C.V. of material. • The recorder of pen can work at a high speed of

100yds/min

Disadvantage of uster evenness tester • The result obtained by this M/C is affected by

moisture content of material . • In this instrument material up to a certain thickness

can be tested . • Expensive more compare to other evenness m/c

Reference:• Uster tester brochure• Application and report hand book of uster

tester • www.encylopediya .(uster5 tester )• Textile testing books.

THANK YOU