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The Peoples University Of BangladeshPresentation on Uster HVI 1000 MachinePresented By:Group C(125,133,134)Presented To:Sabina YesminLecturer, PUB

Date 17.02.2015

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Introduction For many decades the quality characteristics of cotton was determined by human classers

Human classer could categorize fiber length color and trash content quite well

Difficult or Impossible for him to determine fiber fineness short fiber content strength elongation maturity etc.

4 groups of people who had considerable interest to improve the determination of the quality characteristics of cotton: cotton farmers cotton traders cotton research institutes cotton spinners USDA played an important role to push faster test methods to determine all the quality characteristics of a cotton bale within a few seconds. the testing system which was capable to measure the most important quality characteristics within a very short time was named High Volume Instrument (HVI).

Different Components Of USTER HVI 1000Fig. USTER HVI 1000

Fiber length The most important length to be determined with the USTER HVI Systems is the Upper Half Mean Length. This length is equivalent to the classers staple and is defined according to Fig.

FibrogramFig. Represents the Fibrogram, which is a non-end aligned staple dia-gram. UHMLML

The fiber length affects the

Yarn evenness Yarn strength, Yarn elongationand Yarn spinning process 50%

Uniformity Index The fiber uniformity index is the ratio between the Mean Length and the Upper Half Mean Length .This value is expressed in percent Uniformity Index (UI)

%Bale 1UHML=xUI=(y-5)%

Bale 2UHML=xUI=y%Short fiberShort fiber

spinning process increases the unevenness decreases the strength of yarns Effect Of Low UIuniformity index

Micronaire Value The micronaire value is a measure of the fiber fineness and the maturity.

Air Flow

The micronaire value can influence the yarn evenness the entire spinning process Particularly the processing speed in spinning millsThe measurement of micronaire is based on an airflow principle. A cotton sample of 4 grams is entered into an airflow chamber. Fig.airflow chamber.

Fiber strength The fiber strength is determined at the same fiber bundle which is used for fiber length measurement. The jaws are placed 3 mm (1/8 inch) apart.

The unit for fiber strength is Centinewton per tex (cN/tex). Jaw 8/1 space betn clamps Fiber bundle Clamps Fig. Fiber strength measurement

For surviving subsequent processes In weaving process, yarns have to reach a minimum strength yarn strength is deter-mined by the fiber strength considerably.

CombFiber BundleTop Pair JawsBottom Pair Jaws

Fiber Breakage Strength Measurement Principle In USTER HVI Machine

Fiber Length Short fiber content (%) Frequency (%) 25% 50% X% 100%

Short fiber indexThe measure of the short fiber index is based on the fiber length distribution throughout the test specimens. An indication of the amount of fibers that are less than 0.5 inch in length.

Color Grade

The Color Grade is a measure of the reflectance (Rd) and the yellowness (+b) of cotton fibers. These two quality characteristics can also be measured with the HVI System. The determination of the color code is based on the Nickerson-Hunter cotton colorimeter diagram for Upland cotton. The color code can be determined at the point where the reflectance Rd and the yellowness +b intersect on the Nickerson-Hunter scale.

Classers designation for reflectance

WhiteLight spotted Spotted Tinged Yellow stained

Good middling 11* 1213----Strict middling 21* 2223* 2425Middling 31* 3233* 34* 35Strict low middling 41* 4243* 44* --Low middling 51* 5253* 55* --Strict good ordinary 61* 6263* ----Good ordinary 71* --------Below grade 8182838485

N.B.* Physical Standards. All others are descriptive Table : Color Grades of Upland Cotton Classers designation for yellowness

Elongation: Measurement of the elastic behavior of the fiber in the bundle. The distance of the fiber extendbefore they break is called elongation and is expressed is percentage l lo

Fig. Determination of Elongation

Moisture (moist):

Moisture is the amount of percentage of water which present in the specimen being tested. Moisture content of the cotton sample at the time of testing using conductive moisture probe. Moisture in the cotton varies with time temperature and humidity of which the samples have been exposed.

Maturity Index:

The maturity index is a relative value that is calculated using a sophisticated algorithm including the other HVI spectrum measurement such as micronaire strength and elongation. Maturity indicate the degree of cell wall thickness within a cotton sample.

Trash count: Trash is measured on the same glass window as the color measurement. The sample is illuminated from underneath the glass window and a black and white CCD camera analyzes the changes pixels. A trash particle is counted if it exceeds the grayness threshold set in the camera. All particles that cover the glass window are counted one by one and the results are expressed in trash particle count per surface area.Trash Area:The area that is covered by a trash particle is measured at the same time the particle is counted. The area that is covered by a single particle is summed up with all areas of the other particles counted on the surface of the glass window. The result is expressed in relation to the entire measuring area of the glass window and is expressed as percentage "% Area".

For example, a small number of trash counts can result in a high "%Area" value if the particles are large. On the contrary, a high number of particle counts with a small "%Area value indicate the trash is smaller size (i.e. pepper trash).

Trash Grade (Tr grade):

This is the trash or leaf grade that is determined by calibrating the HVI spectrum with known samples. These samples are usually numbered from 1 to 7 with increasing amount of trash as the number gets tangers. The standards used for calibration can be supplied by USDA or established by the official cotton standards agency in any cotton producing country

The first attempt to increase the test speed of cotton classification was made by the United States Department of Agriculture in the late Sixties with the HVI The quality characteristics deter-mined by USTER HVI Systems are known by everybody in the cotton supply chain Conclusions This test system has evolved in the meantime to a universal classi-fication unit which has fulfilled the dreams of the pioneers. Today, with the USTER HVI 1000 a test system is available which can satisfy the needs of the cotton farmer, the cotton trader and the cotton re-search institutes and the cotton spinners.

Thank You All

Any question?