SHORT FIBER CONTENT

GLEN RITCHIE AND BRENDAN KELLY

TEXAS TECH UNIVERSITY / TEXAS A&M AGRILIFE

RESEARCH

http://www.depts.ttu.edu/pss/index.php https://www.instagram.com/texastech/?hl=en

fbri.ttu.edu

Cotton Fiber Development

Fiber length

Fiber diameter

Wall thickness

0 10 20 30 40 50

Anthesis

Boll age

Boll opening

10

20

1

2

3

4

5

10

20

Immature fiber

30

mm

μ μ

Mature Fiber

Immature Fiber

Cotton Fiber Maturation

Pictures: R. Goynes

Defining Fiber Maturity

• Maturity(θ) is the area of

the cell wall, Aw, relative

to the area of a circle

having the same

perimeter, P2, as the fiber

section.

• Fiber maturity (θ) is

expressed as a value

between 0 an 1.

Typical cotton fiber cross-sections

• There is variation in fiber

maturity within every bale,

even “mature” bales.

• Immature fibers can cause

problems during processing,

and can degrade yarn and

fabric quality.

Fiber Length & Uniformity

Within Sample Variability in Cotton Fiber Length

Suter-Webb

Short staple

Long staple

High Volume Instrument

High Volume Instrument Length/Strength Module

High Volume Instrument

Length/Strength Module

AFIS Pro 2

Advanced Fiber Information System (AFIS)

Maturity and Fineness

• AFIS is an individual fiber

tester.

• It uses electro-optical sensors

to measure the length,

maturity, and fineness of

individual fibers in the sample.

• We can compare HVI

Micronaire with AFIS Maturity.

Single fiber

waveform

Single nep waveform

Time of flight

Vo

ltag

e

Average

ribbon width

• The fibrograph is an

instrument that measures the

light attenuation produced by

scanning a sample of parallel

fibers referred to as the fiber

beard.

• The output of the optical

system plotted as a function

of distance is referred to as

the fibrogram

Fibrograph Principle

Research

HVI Fibrogram Length Measurement

0

20

40

60

80

100

0 0,4 0,8 1,2 1,6 2Sta

ndar

diz

ed o

pti

cal

amount

[%]

Distance [in]

1.8% span length(UHML)

7.8% span length(ML)

*UI=

(ML/UHML)x100%

Fiber length

Upper Half Mean DescriptionLength (mm)Below 25 Short25-28 Medium28-32 LongAbove 32 Extra Long

Fiber length uniformity index

UI% DescriptionBelow 77 Very low77 - 79 Low80 - 82 Intermediate83 - 85 HighAbove 85 Very high

Discussion

• The HVI fiber beard is composed of the longest fibers

in the sample.

• Short fibers do not extend from the comb,

and are not included in the fibrogram.

• Short fiber content is an important fiber quality

component, not measured by HVI.

Advanced Fiber Information System (AFIS)

• The Advanced Fiber Information System

(AFIS) is an individual fiber tester.

• The AFIS individualizes fibers, draws

them into and airstream, and assess

their length, maturity and fineness.

• AFIS fiber quality parameters are based

on the complete within sample

distribution of fiber quality.

AFIS Length Distributions

• Fiber length Distribution [“by number” (n)

or “by weight” (w)]: Length distribution by

number provides the relative frequency of fibers

in each of the 40 preset AFIS length bins.

AFIS Length Variability

• Length CV (LnCV or LwCV) [%]: The

coefficient of variation in fiber length by-number

or by weight. CV% is a measure of the standard

deviation (σn or σw) of fiber length within a

sample standardized by average fiber length,

expressed as a percentage.

• Short Fiber Content (SFCn or SFCw) [%]:

The percentage of fibers (by number or by

weight) in a test specimen that is shorter than

12.7 mm in length

Advanced Fiber Information System (AFIS)

• HVI and AFIS are both high throughput cotton

fiber quality assessment technologies.

• Both systems provide parameterizations of fiber

length, and fiber length variability.

HVI AFIS

Length Upper Half Mean

Length

Mean Length by-

number

Length Variability Uniformity Coefficient of

Variation in fiber

length

HVI Fiber Length Parameters

0 1 2

Length [in]

Upper HalfMeanLength(UHML)

MeanLength

AFIS Fiber Length Parameters

0,00

0,02

0,04

0,06

0,08

0,10

0,0 1,0 2,0

Rel

ati

ve

Fre

qu

ency

Length [in]

L(n)RelativeFrequency

UQL(w) [in]

L(n) [in]

AFIS Short Fiber Content (SFC)

0,00

0,02

0,04

0,06

0,08

0,10

0,0 1,0 2,0

Rel

ati

ve

Fre

qu

ency

Length [in]

L(n)RelativeFrequency

SFC (n)[%]

Length Distribution Comparison (Bales with UHML of 1.1in)

0,00

0,01

0,02

0,03

0,04

0,05

0,06

0,07

0,08

0,09

0,10

0,0

0,5

1,0

1,5

2,0

Rel

ati

ve F

req

uen

cy

Length [in]

Length Distribution Comparison (Bales with UI of 81.3)

0,00

0,01

0,02

0,03

0,04

0,05

0,06

0,07

0,08

0,09

0,10

0,0

0,5

1,0

1,5

2,0

Rel

ati

ve F

req

uen

cy

Length [in]

0

5

10

0

0.4

37

5

0.8

75

1.3

12

5

1.7

5

2.1

87

5Fre

qu

ency 1

1

0

5

10

0

0.4

37

5

0.8

75

1.3

12

5

1.7

5

2.1

87

5Fre

qu

ency 7

8

9

10

0

5

10

0

0.4

37

5

0.8

75

1.3

12

5

1.7

5

2.1

87

5Fre

qu

ency 5

6

Fiber breakage related to immature fibers

1

2

3

4

5

6

0

7

8

9

10

11

12

0,00

0,05

0,10

0,15

0,20

0,00 0,25 0,50 0,75 1,00

Rel

ativ

e F

req

uen

cy

Maturity (θ)

Problems caused by immature fibers

• Poor secondary cell wall

development can result in poor

dye performance, or dying

imperfections.

• Immature fibers have a poor

secondary cell wall

development, are weaker, and

will tend to break and entangle

during processing.

• Fiber breakage during

processing degrades fiber

quality and can cause

imperfections in spun yarn

quality.

Discussion

• Short fiber content is affected by fiber length, but

also by fiber strength and maturity.

• We may have unintentionally ignored short fiber

by using HVI

• Short fiber has two sources:

• Immature fibers that do not lengthen sufficiently

• Fibers (often immature) that break during processing

• In Texas, many of the problems with short fiber

content have been tied to maturity, particularly

near the top of the plant.

Acknowledgments:

Fiber and Biopolymer Research Institute

Texas Tech University Crop Physiology Program12º CBA - Congresso Brasileiro do Algodão