Measuring principles USTER ® HVI
Measuring principles
USTER® HVI
USTERUSTER®® HVI SpectrumHVI Spectrum
Test Report
Measurements on cotton:
• Length, uniformity
• Micronaire
• Strength
• Color
• Trash
NEW on USTER® HVI SPECTRUM:
• Maturity Index
• Short Fiber Index
• Moisture Content
History of Cotton ClassingHistory of Cotton Classing
Edgar Degas
“Portraits in a New Orleans Cotton Office”, 1873
Pulling a Length StaplePulling a Length Staple
Fiber BeardComb
HomePosition
Breaker Jaws
Breaker Jaws
LED
D2 = Lens to BreakD1 = Length Standard
• Fiber Length is measured optically by the LEDs, when the fiber beard entered the measuring zone
Length & Strength Measurement
Development of a fibrogram
Mean Length - Mean Length - Principle of MeasurementPrinciple of MeasurementDeveloped from the fibrogram
Mean lengthML
100%0%
Length
Tangent from origin
Upper Half Mean Length -Upper Half Mean Length -Principle of MeasurementPrinciple of MeasurementDeveloped from the fibrogram
Upper half mean lengthUHML
100%0% 50%
Length
Tangent from 50% amount
Comparison Mean Length - Upper Half Mean Length
Upper half mean length
Mean length
100%0% 50%
Length
Staple diagram
Fiber length
100%0% 50%
Comparison Fibrogram - Staple Diagram
Fibrogram
• non end-aligned diagram of the fiber length
• calculated from a randomly taken fiber bundle which is fixed in a measuring grip
Staple Diagram
• end-aligned diagram of the fiber length
• distribution curve (histogram) of all fiber lengths
Explanation to the length
1 inch = staple class 32 32:32 = 1
1 1/16 inch = staple class 34 34:32 = 1 1/16
1 1/2 inch = staple class 48 48:32 = 1 1/2
Inches UHML [inches] UHML [mm] LengthCode
Below 13/16 < 0.79 < 20.1 24 13/16 0.80 - 0.85 20.1 - 21.6 26 7/8 0.86 - 0.89 21.8 - 22.6 28 29/32 0.90 - 0.92 22.9 - 23.4 29 15/16 0.93 - 0.95 23.6 - 24.1 30 31/32 0.96 - 0.98 24.4 - 24.9 31 1 0.99 - 1.01 25.1 - 25.8 32 1 1/32 1.02 - 1.04 25.9 - 26.4 33 1 1/16 1.05 - 1.07 26.7 - 27.2 34 1 3/32 1.08 - 1.10 27.4 - 27.9 35 1 1/8 1.11 - 1.13 28.2 - 28.7 36 1 5/32 1.14 - 1.17 29.0 - 29.7 37 1 3/16 1.18 - 1.20 30.0 - 30.5 38 1 7/32 1.21 - 1.23 30.7 - 31.2 39 1 1/4 1.24 - 1.26 31.5 - 32.0 40 1 9/32 1.27 - 1.29 32.3 - 32.8 41 1 5/16 1.30 - 1.32 33.0 - 33.5 42 1 11/32 1.33 - 1.35 33.8 - 34.3 43 1 3/8 > 1.36 > 35.0 44
Length Classification for Upland Cotton
Inches UHML [inches] UHML [mm] LengthCode
Below 1 1/4 < 1.20 < 30.5 40 1 5/16 1.21 - 1.25 30.7 - 31.8 42 1 3/8 1.26 - 1.31 32.0 - 33.3 44 1 7/16 1.32 - 1.36 33.5 - 34.5 46 1 1/2 1.37 - 1.42 34.8 - 36.1 48 1 9/16 1.43 - 1.47 36.3 - 37.3 50 1 5/8 > 1.48 > 37.6 52
Length Classification for Pima Cotton
Uniformity Index
Indication of the distribution of fiber length within the fibrogram fiber length variation
ML = Mean Length
UHML = Upper Half Mean Length
Uniformity Index UI = ML x 100UHML
Uniformity Index (%)
Uniformity Index (%) Description
Below 77 Very low
77 to 80 Low
81 to 84 Medium
85 to 87 High
87 and higher Very High
Uniformity Index: Describes how evenly the fiber length is distributed within a cotton sample
USTER® HVI SPECTRUM
Features & Benefits:
Accurate and precise Short Fiber Index
Detects high short fiber content bales quickly and
accurately
Proven algorithm under evaluation by USDA
High correlation to AFIS Short Fiber Content
USTER® HVI SPECTRUM
Staple Standards Staple Standards Evaluation CottonsEvaluation Cottons Test - r = 0.98 Test - r = 0.98
6
8
10
12
14
16
31 32 32 34 35 36 37 38
Sh
ort
Fib
er C
on
ten
t/ I
nd
ex [
%]
AFIS HVI
Short Fiber Index (%) Description
Below 6 Very low
6 to 9 Low
10 to 13 Medium
14 to 17 High
18 and higher Very High
Short Fiber Index (SFI): The amount of fibers in the cotton sample shorter than 0.5” or 12.7 mm
Short Fiber Index (SFI)
• The fiber beard is broken at a continuous extension rate and with a 1/8-inch distance between the clamps.
• Within the space of 1/8-inch, the fibers will break at their weakest spot, not at a predetermined breaking-point (clamp).
Bundle Fiber StrengthPrinciple of Measurement
• The bundle strength is the breaking strength of the
cotton fibers in grams per tex. The fineness is calculated from the Micronaire value.
Bundle Fiber Strength
Principle of Measurement
Fiber BeardComb
HomePosition
Breaker Jaws
Breaker Jaws
LED
D2 = Lens to BreakD1 = Length Standard
• The breaker jaws (clamps) are set at 1/8” (or 3.2 mm) distance for measuring fiber strength
• Force is applied by constant rate of extension (CRE)
USTER® HVI – Length & Length & StrengthStrength
MeasurementMeasurement
Strength (g/tex) Description
Below 21 Very low
22 to 24 Low
25 to 27 Medium
28 to 30 High
31 and higher Very High
• Yarn strength depends highly on the Fiber Strength in the cotton (short/medium staple)
Strength (g/tex)
Clamp
Clamp
= x 100 [%]ll0
USTER® HVI – Bundle Fiber Elongation Bundle Fiber Elongation
Principle of MeasurementPrinciple of Measurement
• Measurement of the elastic behavior of the fibers
in the bundle
• The distance the fibers extend before they break
is expressed as percent elongation:
MicronaireMicronaire
Measurement PrincipleMeasurement Principle
1. Closing Valve
2. Pressure Regulating Valve
3. Air Measuring Device
4. Pressure Change Measuring Device
5. Measuring Chamber with Fibers
Micronaire MeasurementMicronaire Measurement
Air flow
coarse fibers,low air resistance
(high Micronaire value)
fine fibers,high air resistance
(low Micronaire value)
Micronaire MeasurementMicronaire Measurement
• A fiber sample of constant weight is
measured by passing air through the
fibers and measuring the drop in pressure.
• Maturity has an influence on micronaire
results.
Micronaire - Influences
• Genetic factors of the cotton, which have an
influence on the diameter of the fiber. For
example Pima cotton has a lower micronaire
value than Upland cotton.
• Environmental influences, e.g. soil, fertilizer,
humidity and temperature, duration of
growing period
Micronaire - Consequences
Low Micronaire
• Can tend to the formation of neps in yarn and fabric
• If they are mature, they are fine and strong
• If they are immature, they are weak
• Immature fibers absorb less dye and can lead to problems in dyeing (shiny neps)
High Micronaire
• Mostly mature and strong fibers
• Limits the yarn count
• Fine yarns cannot be spun.
Micronaire Description
Below 3.0 Very Fine
3.1 to 3.6 Fine
3.7 to 4.7 Medium
4.8 to 5.4 Coarse
Above 5.5 Very Coarse
The Micronaire indicates the average “fineness” of a cotton sample, based on an airflow measurement.
Micronaire
Relationship Between Maturity and Relationship Between Maturity and MicronaireMicronaire
Fine and immature, very low Micronaire
Fine and mature, low Micronaire
Coarse and immature, low Micronaire
Coarse and mature, high Micronaire
USTER® HVI SPECTRUM
0,6
0,8
1
1,2
1 6 11 16 21 26 31 36 41 46 51 56 61 66 71
Mat
uri
ty R
atio
AFIS HVI
International Cotton Samples - r = 0.93International Cotton Samples - r = 0.93
Maturity IndexMaturity Index
• The maturity index is a relative value calculated
from the HVI measurements of
- micronaire
- strength
- elongation
• Indicates the degree of cell wall thickness
Maturity Index Description
Below 0.75 Uncommon
0.75 to 0.85 Immature
0.85 to 0.90 Mature
Above 0.95 Very Mature
The Maturity Index (Mat) indicates the average degree of cell wall thickness within a cotton sample(short/medium staple)
USTER® HVI – Maturity
Micronaire & Maturity
Low Micronaire &
“fairly mature”
Medium Micronaire &
“less mature”
Medium Micronaire &
“fairly mature”
High Micronaire &
“well mature”
Cotton ColorCotton Color
Principle of MeasurementPrinciple of Measurement
Two-dimensional range of the cotton color
Cotton ColorCotton Color and Trashand Trash
Principle of MeasurementPrinciple of Measurement
• Rd = Reflectance; the whiteness of the light that is reflected by the cotton fibers
• +b = Yellowness; the yellowness of the light that is reflected by the cotton fibers
• Color Grade = Combination of Rd and +b; representing official USDA Upland Grade Standards
Cotton ColorCotton Color
Principle of MeasurementPrinciple of Measurement
Cotton ColorCotton Color
USDA Upland USDA Upland
Cotton Color ChartCotton Color Chart
Color Grade Symbols Code White Good Middling Strict Middling Middling Strict Low Middling Low Middling Strict Good Ordinary Good Ordinary
GM SM Mid SLM LM SGO GO
11 21 31 41 51 61 71 81
Light Spotted Good Middling Strict Middling Middling Strict Low Middling Low Middling Strict Good Ordinary Good Ordinary
GM Lt Sp SM Lt Sp Mid Lt Sp SLM Lt Sp LM Lt Sp SGO Lt Sp GO Lt Sp
12 22 32 42 52 62 82
Spotted Good Middling Strict Middling Middling Strict Low Middling Low Middling Strict Good Ordinary Good Ordinary
GM Sp SM Sp Mid Sp SLM Sp LM Sp SGO Sp GO Sp
13 23 33 43 53 63 83
Tinged Strict Middling Middling Strict Low Middling Low Middling Strict Good Ordinary
SM Tg Mid Tg SLM Tg LM Tg SGO Tg
24 34 44 54 84
Yellow Stained Strict Middling Middling
SM YS Mid YS
25 35 85
Cotton Color Cotton Color and Trashand Trash
USDA Color Code USDA Color Code
DescriptionDescription
Cotton ColorCotton Color
USDA Upland USDA Upland
Cotton Color ChartCotton Color Chart
Cotton ColorCotton Color
USDA Pima Cotton USDA Pima Cotton
Color ChartColor Chart
Video image
analysis
resulting in:
• Trash % Area (covered)
• Trash (Particle) Count
Cotton Trash Cotton Trash Principle of MeasurementPrinciple of Measurement
• Trash Count = the number of trash particles in the cotton sample on the measurement area
• Trash Area = indicates the size of trash in the cotton sample covering the measurement area
• Trash Grade = Determined by Trash Area, and compared to USDA Leaf Grade Standards
Cotton Trash Cotton Trash Principle of MeasurementPrinciple of Measurement
Classer‘s Leaf Grade
Trash Measurement
(% area)
1 2 3 4 5 6 7 8
<= 0.13 <= 0.20 <= 0.34 <= 0.51 <= 0.72 <= 1.00 <= 1.25 > 1.57
* 2001 USDA crop data (4 year average)* 2001 USDA crop data (4 year average)
Cotton Trash Cotton Trash Relationship of Trash Measurement to Classer’s Relationship of Trash Measurement to Classer’s
Leaf Grade*Leaf Grade*
Features & Benefits:
• Moisture is the amount (%) of water that is present in the sample being tested
• Patented resistance moisture sensor
• Direct measurement
• Consistent pressure ensures repeatable moisture results
• No customer calibration required
USTER® HVI – Cotton Moisture ContentCotton Moisture Content
Principle of MeasurementPrinciple of Measurement
Moisture Content (%) Description
Below 4.5 Very low
4.5 to 6.5 Low
6.5 to 8.0 Medium
8.0 to 10.0 High
10.0 and higher Very High
• In order to give repeatable and comparable test results, the Moisture Content of the cotton sample at the time of testing should be between 6.5 to 8.0%
Cotton Moisture ContentCotton Moisture Content