'Baer’s Comb Sorter\r'

'Baer’s strip Sorter get out Fibre space: The â€Å" space” of cotton types is a property of commercial range as the price is gener entirelyy ground on this character. To some extent it is true, as different factors being equal, longer cottons whollyow better spinning performance than misfortunateer 1s. scarce the continuance of a cotton is an enigmatical quantity, as the fibres, even in a fiddling random bunch of a cotton, vary enormously in distance. undermenti angiotensin converting enzymed be the various measures of length in use in diametrical countries recollect length:It is the ventured quantity which theoretic anyy signifies the arithmetical think of of the length of all the fibres return in a small solely re reconcileative ideal of the cotton. This quantity spate be an average according to any number or system of weights. Upper quartile length: It is that value of length for which 75% of all the observed values ar lower, and 25% blueer. Effective length: It is difficult to break away a clear scientific definition. It whitethorn be delineate as the stop number quartile of a numerical length dispersion liminated by an arbitrary construction. The fibres eliminated are briefer than half(a) the effective length. Modal length: It is the virtually frequently occurring length of the fibres in the sample and it is related to mean and median for reorient distributions, as exhibited by fibre length, in the follwing way.(Mode-Mean) = 3(Median-Mean) where, Median is the particular value of length above and below which exactly 50% of the fibres lie. 2. 5% Span length: It is delimitate as the distance coupletned by 2. % of fibres in the specimen being strong-tried when the fibres are parallel of latitudeized and randomly distributed and where the initial showtime gunpoint of the scanning in the interrogatory is considered atomic number 6%. This length is measured exploitation â€Å"digital FIBROGRAPH ”. 50% Span length: It is defined as the distance spanned by 50% of fibres in the specimen being tested when the fibres are parallelized and randomly distributed and where the initial starting point of the scanning in the test is considered 100%. This length is measured using â€Å"DIGITAL FIBROGRAPH”.The S go forthh India Textile question Association (SITRA) gives the undermentioned empirical relationships to estimate the Effective length and Mean Length from the Span Lengths. Effective length = 1. 013 x 2. 5% Span length + 4. 39 Mean length = 1. 242 x 50% Span length + 9. 78 Baer’s Comb sorter Method: For the determination of the length and of the length distribution of cotton fibers in purified cotton the Baer’s Comb Sorter rule acting: These directions describe the mode of procedure that is well adapted to the sorter* most extensively use in the United States at the usher time.Apparatus†The sorter Duplex Cotton Fiber Sorter consists of two cambers of extricates rigidly mount side by side on a popular base. from to separately whizz one bank of combs consists of at to the lowest degree 12 individual combs spaced 3. 2 mm isolated, one behind the other, and mounted in grooves so that as they are approached during the fractionating process and no longer needed, they whitethorn be dropped below the working plane. Each individual comb has a wiz row of accurately aligned and crisply pointed teeth, 12 mm long, consisting of needles 0. 38 mm in diameter. The teeth are spaced 62 to 25 mm oer an extent of roughly 50 mm.Accessory equipment consists of fiber-sorter forceps, fiber-de crush outing grid, fiber-depressing mobile plate, and velvet-covered plates. The sorter forceps consist of two brass pieces approximately 75 mm long, hinged on one end and slightly editd to present a beaked aspect at the enamorping end for gripping the jut out fibers close to the come forths of the combs. Usually, one of the gripping ed ges has a leather or other powerful padding. The gripping edge is approximately 19 mm wide. The fiber-depressing grid consists of a serial of brass rods spaced 3. mm apart so that they whitethorn be set(p) surrounded by the combs to press the fibers down between the teeth. The fiber-depressing smooth plate consists of a nice brass plate approximately 25 ? 50 mm, with a knob or handle on the upper surface whereby the plate may be smoothed over the fibers as they are displace on the velvet surface of the get down plates. The velvet-covered plates, upon which the fibers may be arrayed, are aluminium sheets approximately 100 mm ? 225 mm ? 2. 4 mm thick, covered on both sides with high-grade velvet, preferably black.Standard ambiance For Testing: The atmosphere in which personal tests on textile materials are performed. It has a carnal knowledge humidity of 65 + 2 per cent and a temperature of 20 + 2° C. In tropical and sub-tropical countries, an alternative exemplar atmo sphere for testing with a relative humidity of 65 + 2 per cent and a temperature of 27 + 2° C, may be used. Procedure With the fiber-depressing grid cautiously insert the weighed test portion into one bank of combs of the cotton sorter, so that it extends crosswise the combs at approximately right angles.With the sorter forceps, grip by the free ends a small portion of the fibers extending with the teeth of the comb darlingest to the operator; gently and swimmingly draw them forward out of the combs, and commute them to the tips of the teeth in the second bank of combs, laying them parallel to themselves, rightful(a), and approximately at right angles to the faces of the combs, release the gripped ends as near to the face of the forepart comb as possible. With the depressor grid carefully press the headred fibers down into the teeth of the combs.Continue the ope circumscribe until all of the fibers are transferred to the second bank of combs. During this transfer of the fibers, drop the combs of the offshoot bank in succession when and as all of the project fibers have been removed. Turn the machine through 180, and transfer the cotton fibers back to the first bank of combs in the manner set forth in the preceding paragraph. Take enceinte care in evening up the ends of the fibers during both of the above transfers, arranging them as closely as possible to the straw man surface of the proximal comb.Such evening out of the ends of the protruding fibers may involve displace out straggling fibers from both the comportment and rear aspects of the banks of combs, and re-depositing them into and over the main clomp in the combs. Turn the machine over again through 180. Drop successive combs if obligatory to expose the ends of the longest fibers. It may be necessary to re-deposit some straggling fibers. With the forceps unpack the few most protuberant fibers. In this way continue to withdraw in turn the remaining protuberant fibers back to the front face of the proximal comb.Drop this comb and plagiarize the series of operations in the akin manner until all of the fibers have been pull out. In order not to nonplus seriously the portion being tested, and thereby vitiate the length fractionation into length multitudes, make several pulls (as many as 8 to 10) between each orthodontic braces of combs. Lay the pulls on the velvet-covered plates alongside each other, as straight as possible, with the ends as clearly defined as possible, and with the distal ends arranged in a straight line, pressing them down gently and smoothly with the fiber-depressing smooth plate before releasing the pull from the forceps.Employ not fewer than 50 and not more than 100 pulls to separate the test portion. Group unneurotic all of the fibers measuring 12. 5 mm (about 1/2 inch) or more in length, and weigh the group to the nearest 0. 3 mg. In the similar manner, group together all fibers 6. 25 mm (about 1/4 inch) or less in length, and w eigh in the same manner. Finally, group the remaining fibers of intermediate lengths together and weigh. The heart of the three weights does not protest from the initial weight of the test portion by more than 3 mg.Divide the weight of each of the first two groups by the weight of the test portion to obtain the function by weight of fiber in the two ranges of length. Geometrical Construction of Comb Sorter Diagram Figure . Geometrical abstract of comb sorter diagram 1. Q is the mid-point of OA, i. e OQ = ? OA. 2. From Q draw QP? parallel to OB to cut the curve at P?. 3. Drop the normal P? P. 4. motley fool off OK equal to ? OP and erect the perpendicular K? K. This is a first a musical theme to the effective length. 5. S is the mid-point of K? K 6. From S draw SR? parallel to OB to cut the curve at R?. 7.Drop the perpendicular R? R. 8. Mark off OL equal to ? OR. 9. Erect the perpendicular L? L. This is the effective length. Fibre Length Variation: Even though, the long and s hort fibres both contribute towards the length mental defectiveness of cotton, the short fibres are particularly trustworthy for increasing the waste losses, and cause variableness and reduction in strength in the recital spun. The relative proportions of short fibres are ordinarily different in cottons having different mean lengths; they may even differ in two cottons having nearly the same mean fibre length, rendering one cotton more irregular than the other.It is wherefore important that in addition to the fibre length of a cotton, the degree of freakishness of its length should also be known. variant is denoted by any one of the following attributes Co-efficient of variation of length (by weight or number) irregularity fate Dispersion percentage and percentage of short fibres Uniformity ratio Uniformity ratio is defined as the ratio of 50% span length to 2. 5% span length denotative as a percentage. uniformity ration = (50% span length / 2. 5% span length) x 100 unifor mity index number = (mean length / upper half mean length) x 100 Short Fibres:The blackball effects of the presence of a high proportion of short fibres is well known. A high percentage of short fibres is usually associated with, †Increased yarn irregularity and ends dddown which focus quality and increase processing cost †Increased number of neps and slubs whiiich is detrimental to the yarn appearance †Higher fly acquittance and machine contttamination in spinning, weaving and knitwork operations. †Higher wastage in combing and other oppperations. While the detrimental effects of short fibres have been well established, there is thus far considerable debate on what constitutes a ‘short fibre.In the simplest way, short fibres are defined as those fibres which are less than 12 mm long. An estimate of the short fibres was do from the staple diagram obtained in the Baer Sorter method Short fibre content = (RB/OB) x 100References: 1. â€Å"TE05046Physic alTextileTestingandQualityControl. medico. ” Www. most. gov. mm. MINISTRY OF SCIENCE AND TECHNOLOGY DEPARTMENT OF practiced AND VOCATIONAL EDUCATION GOVERNMENT technical COLLEGES/INSTITUTES DEPARTMENT OF TEXTILE ENGINEERING, n. d. Web. ;lt;http://www. most. gov. m/techuni/media/TE05046PhysicalTextileTestingandQualityControl. doc;gt;. 2. Kohli, Nitesh. Fibre Testing. Scribd. com. N. p. , 18 May 2009. Web. ;lt;http://www. scribd. com/doc/15569730/Fibre-Testing;gt;. 3. â€Å"FIBRE TESTING. ” Textiletechinfo. com. N. p. , n. d. Web. 25 July 2012. ;lt;http://textiletechinfo. com/spinning/fibretesting. htm;gt;. 4. Tirumalai, Radhakrishna S. â€Å" customary Chapters: COTTON. ” Http://www. pharmacopeia. cn. N. p. , n. d. Web. 25 July 2012. ;lt;http://www. pharmacopeia. cn/v29240/usp29nf24s0_c691. html;gt;\r\n'