HVI1

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

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

Staple Standards Staple Standards Evaluation CottonsEvaluation Cottons Test - r = 0.98 Test - r = 0.98

31 32 32 34 35 36 37 38

AFIS HVI

Short Fiber Index (%) Description

Below 6 Very low

6 to 9 Low

10 to 13 Medium

14 to 17 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

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

• Yarn strength depends highly on the Fiber Strength in the cotton (short/medium staple)

Strength (g/tex)

= 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

1 6 11 16 21 26 31 36 41 46 51 56 61 66 71

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

Two-dimensional range of the cotton color

Cotton ColorCotton Color and Trashand Trash

• 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

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

USDA Upland USDA Upland

Cotton Color ChartCotton Color Chart

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

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

HVI1

length uhml

length classification

length code

high bundle fi

high short fi

fi rogram p fi

length staple t tr t

index sfishort fi

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