short fiber content - cbacongressodoalgodao.com.br/arquivos/16h30_-_glenn_ritchie.pdf · advanced...
Post on 03-Jun-2020
11 Views
Preview:
TRANSCRIPT
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
top related