Instrumentsfor the Measurement of Fiber Properties
Instrumentsfor the Measurement of Fiber Properties
AshfordSuperfine Drum Carder
Theinstrument, Ashford Superfine Drum Carder, was used to prepare about50 mg of superfine wool slivers. The instruments prepared sliver andsmooth fiber by rotating at the speed ratio of about 6:1. The drumhas a length of about 20 cm. The operator loosened the two knobs oncethe large drum started collecting the fiber from the small one. Afterloosening the knobs, the operator twisted the packer brush up andtook it out of the teeth. The sliver was then taken out of thecarder. The main function of the packer brush that is located in thecarder is to pack the fiber and take it to the teeth. The teeth arelocated in the large drum, which implies that the brush feeds it withthe fiber. This process of feeding the large drum allowed theoperator to card more fiber, which resulted in the production of athicker sliver.
Themeasurement of diameter distribution characteristics and length ofthe sliver was accomplished using the OFDA4000. Some of the keycharacteristics of the slivers that were measured using thisinstrument include the CVH, Hauteur, curvature, mean diameter,length-diameter profile, and CVD. The measurement of all theaforementioned characteristics was done in a single operation. Theinstrument was developed using the OFDA2000 technology. It waslaunched in the year 2000 at IWTO, but it was introduced in 2002 tothe players in the textile sector [225,329,553,612,614-619].The OFDA4000applies the same principles as the OFDA2000. For example, the twomachines apply image analysis and automated microscope procedures todetermine different characteristics of the fiber. The measurement ofthe diameter, length profiles, and preparation of the specimen fortesting is accomplished with the help of the beard preparer. Opticalscanning techniques are used to determine the length as well as itsdistribution along each piece of fiber. Optical techniques involvethe application of mathematical models. For example, the operator isexpected to generate values that can be used to estimate the Bard’eand Hauteur capacitance-base distribution by computing thecapacitance distribution .
Theinstrument produces a weighted length. The length distribution isequal to the value of Hauteur distribution. This phenomenon occurswhen the diameter fails to change along the beard, in spite of theobservation of a significant diameter profile . The OFDA4000operates in the ‘native’ mode during the measurement of diameterand length distribution. It operates in the ’70 mm’ mode when theoperator intends to measure the diameter distribution only . Adraft paper that proposed the development of theOFDA4000 machinewas presented in the IWTO meeting that was held in the city ofBarcelona in the year 2005 .
TheIWTO gave the permission for the presentation of the Draft TestMethod in the same year (2005) in order to facilitate the assessmentof the functionality of the instrument. This approval was issued bythe organization’s Regulations Committee. The test focused on twoareas, including the measurement of diameter and length of thesliver. The test conducted by Baxter and Brims showed that theperformance of OFDA4000 instrument was consistent with the data thatwas provided in DTM-62, which was a test method issued by the IWTO in2005 . This test was done on a commercial scale in three milllaboratories. Balasingam et al.  confirmed the functionality ofOFDA4000 by comparing the test results of Almeter with the outcome ofmore than 900 tops.
Thisinstrument is used to facilitate the on-farm determination of wool’sdiameter profile. It was launched in the year 2000 by Brims et al.during the IWTO’s meeting. However, the idea of developing theOFDA2000 was first introduced in 1999 . The instrument ispreferred by many farmers because it has a high level of precisionand accuracy. It is used to accomplish various tasks, including thedetermination of the diameter-length profile. The data that isgenerated by the OFDA2000 can be used in the processing of predictionmodels. This instrument is applied when there is a need to determinethe fiber diameter features along the length of the micro-staple thatis greasy. The greasy micro-staple is prepared from the fiber that isdrawn from the site that is considered to be consistent in each ofthe fleeces. This is common in the pin-bone or the mid-rib of theanimal [334, 466,485,493].
Accordingto Brown et al. the measurement of a single stable cannot providereliable data that can be used to establish the difference betweenfibers that are harvested from different animals . However, thedata obtained from the measurement of features of a single staple canbe used to show the reliable average value of a group of mammals.OFDA2000 has the capacity to correct variations in ambient humidityand temperature. The instrument also performs the flock-specificcorrection, especially in greasy fiber. The average value of greasecorrection factor is estimated to be about 1.4 microns .However, this value is diameter dependent and it is bound to varybetween flocks . The instrument may be used in the post-shearingassessment of the sliver. However, OFDA2000 is mostly used in thedetermination of the key features of the fiber during thepre-shearing period .
Thelevel of accuracy and precision of the instrument has been tested inseveral studies that focused on the on-farm assessment of thefeatures of the sliver [339, 466, 474, 486, 498, and 509]. Thetechnical performance of the instrument in the on-farm assessment ofthe characteristics of the fiber was tested in a study that wasfinanced by AWI. The aforementioned study concluded that themid-side fiber is usually over-represented in the fleece. Inaddition, several researchers have confirmed that the instrument canbe used to determine the diameter profile, strength of the staple aswell as its strength, processing performance, and the farm management[223,287,507,518and 533]. The purpose of developing the on-farm techniques was toenhance the farm management practices, including animal breeding.However, attempts have been made to relate on-farm measurement toprediction of hauteur as well as the processing performance.Moreover, several researchers have proposed the application of theprofile of staple fiber diameter in processing prediction  andenhancement of the formula used to predict aspects involved in theconversion of fiber [486,521,537 and 541].
SIFANis an instrument that is mainly used in the determination of thediameter profile of one wool fiber. Its application was described byPeterson et al. . In addition, the application of SIFAN 3001 wasconfirmed by Wang et al., who focused on the determination ofdiameter profile as well as the measurement precision of theinstrument. Wang et al. identified that the average diameter profilewithin a given staple can be successfully determined using a sampleof 50 mid-size fibers [287, 390]. The instrument can also be used inthe measurement of the breaking force and the diameter profile of asingle piece of fiber [889, 991].
Thisinstrument was exhibited for the first time at ITMA in the year 1996.It is a product of CSIRO and it is mainly used in the determinationof the bundle strength of the fiber . The strength of a bundleis always smaller than that of a single fiber . Its applicationin tops was assessed by Yang et al., who concluded that tenacity ofthe yarn changes in a way that is proportional to that of a bundle.The instrument measures the strength of a bundle using a threemillimeter gauge length.