1、BRITISH STANDARD BS ISO 4912:1981 Textiles Cotton fibres Evaluation of maturity Microscopic method ICS 59.060.10 NO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAWBS ISO 4912:1981 This British Standard, having been prepared under the direction of the Materials and Chemicals Secto
2、r Policy and Strategy Committee, was published under the authority of the Standards Policy and Strategy Committee on 21 May 2002 BSI 21 May 2002 ISBN 0 580 39669 X National foreword This British Standard reproduces verbatim ISO 4912:1981 and implements it as the UK national standard. It supersedes B
3、S 3085:1981 which is withdrawn. The UK participation in its preparation was entrusted to Technical Committee TCI/24, Physical testing of textiles, which has the responsibility to: A list of organizations represented on this committee can be obtained on request to its secretary. Cross-references The
4、British Standards which implement international or European publications referred to in this document may be found in the BSI Standards Catalogue under the section entitled “International Standards Correspondence Index”, or by using the “Find” facility of the BSI Standards Electronic Catalogue. A Br
5、itish Standard does not purport to include all the necessary provisions of a contract. Users of British Standards are responsible for their correct application. Compliance with a British Standard does not of itself confer immunity from legal obligations. aid enquirers to understand the text; present
6、 to the responsible international/European committee any enquiries on the interpretation, or proposals for change, and keep the UK interests informed; monitor related international and European developments and promulgate them in the UK. Summary of pages This document comprises a front cover, an ins
7、ide front cover, the ISO title page, the ISO foreword page, pages 1 to 8, an inside back cover and a back cover. The BSI copyright date displayed in this document indicates when the document was last issued. Amendments issued since publication Amd. No. Date CommentsInternational Standard INTERNATION
8、AL ORGANIZATION FOR STANDARDIZATION.MEMYHAPOLIHAR OPI-AHbl3AI-W l-IO CTAHAPTH3AlWlORGANISATION INTERNATIONALE DE NORMALISATION Textiles - Cotton fibres - Evaluation of maturity - Microscopic method Textiles - Fjbres de coton - haiuation de Ia maturitk - Methode bar microscopie First edition - 1981-0
9、6-01 U DC 677.21.017 Ref. No. ISO 4912-1981 (E) Descriptors : textiles, cotton fibres, tests, estimation, maturation conditions, sampling, test specimen conditioning. Price based on 8 pages Foreword ISO (the International Organization for Standardization) is a worldwide federation of national Standa
10、rds institutes (ISO member bedies). The work of developing Inter- national Standards is carried out through ISO technical committees. Every member body interested in a subject for which a technical committee has been set up has the right to be represented on that committee. International organizatio
11、ns, governmental and non-governmental, in liaison with ISO, also take part in the work. Draft International Standards adopted by the technical committees are circulated to the member bodies for approval before their acceptance as International Standards by the ISO Council. International Standard ISO
12、 4912 was developed by Technical Committee ISO/TC 38, Texti/es, and was circulated to the member bodies in September 1979. lt has been approved by the member bodies of the following countries : Australia Belgium B razil Bulgaria Canada China Cyprus Denmark Egypt, Arab Rep. of Finland The member bodi
13、es of on technical grounds : the following cou 0 Germany, F. R. Ghana Indonesia Italy Japan Korea, Rep. of New Zealand Norway Poland Portugal expressed disapproval of the docu ment Czechoslovakia France India USSR lanoitanretnI noitaknagrO rof ,noitakdradnatS 1891 Romania South Africa, Rep. of Spain
14、 Sweden Switzerland Turkey United Kingdom USA Venezuela Y ugoslavia detnirP ni dnalreztiwS INTERNATIONAL STANDARD ISO 48124981 (El Textiles - Cotton fibres - Evaluation of maturity - Microscopic method 0 lntroduction The term “cotton fibre maturity” is commonly used to signify the extent of fibre wa
15、ll development. For cottons of similar length and perimeter, mature cottons (thick walled) generally give fewer neps, are usually more lustrous, and dye deeper in shade than immature (thin walled) cottons. lmmature fibres have the following characteristics : 1) they break easily during processing; 2
16、) they have a tendency to form neps; 3) they have a tendency for becoming entangled around leaf and trash particles, thus making cleaning more difficult and increasing the amount of fibre removed as waste; 4) they have an adverse effect on yarn appearance; 5) they do not dye evenly in shade. Since c
17、otton fibres vary in both wall thickness and perimeter, fibre maturity is best characterized in terms of a ratio or average percentage of maturity representing the average degree of wall thickening, independent of perimeter. These values are derived from visual comparisons of wall thickness with max
18、imum fibre width, after the fibres have been swollen in 18 % (mlm) sodium hydroxide Solution. As measurement of the degree of wall thickening is too laborious for most practical purposes, this method of deter- mination of maturity of cotton fibres is an indirect test. lt con- sists of an appraisal b
19、ased on judgment and experience, and is suitable for routine research purposes. 1 Scope and field of application This International Standard specifies a method for the evalua- tion of the maturity of raw cotton fibres, or fibres taken from cotton articles which have not been chemically processed. lt
20、 is applicable to test specimens taken at random. Annex B describes other methods of sampling, based on fibre Sorter diagrams, or arranged fibres, which permit slightly more ac- curate appraisals of fibre maturity. 2 References ISO 139, Textiles - Standard atmospheres for conditioning and testing. I
21、SO 1130, Textile fibres - Some methods of samphng for tes hg. 3 Definitions For the purpose of this International Standard, the following definitions apply. 3.1 In the case of Option 1, maturity ratio 3.1.1 dead fibres : Fibres which, after swelling, have a wall thickness of one-fifth or less of the
22、 maximum fibre width. Dead fibres are present in various forms, from flat ribbons with no convolutions and little or no fibre wall (figure 21, to highly convoluted forms with somewhat greater development (figure 1). 3.1.2 normal fibres : Fibres which, after swelling, appear rod-like with a discontin
23、uous lumen. Normal fibres have no well defined convolutions (figures 5 and 6). 3.1.3 thin-walled fibres : Fibres which, when swollen, can- not be classed in the normal or dead groups (figures 3 and 4). 3.1.4 degree of fibre wall thickening : The ratio of actual Cross-sectional area of the wall to th
24、e area of the circle with the same perimeter. 3.1.5 maturity ratio : The ratio of the degree of wall thicken- ing to a Standard degree of thickening selected arbitrarily to equal 0,577. 1 ISO 4912-1981 (EI 32 . In the case of Option 2, percent maturity 3.2.1 immature fibre : Fibre which, upon swelli
25、ng, either assumes a spiral form (figure 8) or lies flat, thinly outlined and almost transparent (figure 9). lt has a wa fibre width II th ickness of less than one-fourth of the maximum 3.2.2 mature fibres : Fibres, the cell Walls of which have developed sufficiently so that, upon swelling, they bec
26、ome un- convoluted and almost rod-like in shape (figure 7). The wall width maximum width is equal to or g reater than one-fourth of its 3.2.3 percent maturity : The average percentage of fibres in a sample, based on the total number of fibres mature 4 Apparatus and reagent NOTE - Photographs and Sta
27、ndard cotton samples are useful for training and check testing purposes. (See annex A for sources of this material. ) 4.1 Microscope or microprojector, fitted with a mechanical traversing Stage and substage condenser, giving a magnification of x 400, and equipped with a viewing aid such as a project
28、ion device or white matt Screen. A magnification of x 150 may be used by agreement between the Parties con- cerned. 4.2 Microscope slides, dissecting needle. 4.3 Counters classif ication . cover glasses, glass rod, registers, if required, for each fibre 4.4 Sodium hydroxide Solution (2 = 1,198 + 0,0
29、02 g/ml), diluted to 18 k 0,2 % (mlm). 5 Conditioning and testing atmosphere Conditioning is not necessary and the test may be carried out in any prevailing atmosphere. However, the fibres are easier to mount when the atmosphere has a relative humidity of at least 40 % at the temperature used. 6 Pre
30、paration of test Sample Prepare the test Sample by one of the following methods. 6.1 From the laboratory bulk Sample previously treated by a mechanical blender, take two series of five test samples, each consisting of a tuft of about 2 mg. Double and draw each test sample several times to mix and pa
31、rallelize the fibres and so per- mit the easy withdrawal of a test specimen. 6.2 Take two laboratory test samples of approximately 10 mg in accordance with ISO 1130, using at least 32 and preferably 64 pinches of fibres taken from various Parts of the laboratory bulk Sample. Double and draw each Sam
32、ple between the fingers several times to mix and parallelize the fibres, and then Split it lengthways into five test samples of about equal size. 7 Preparation of specimens 7.1 The determination of fibre maturity shall be based on the examination and classification of duplicate sets of five test spe
33、cimens, each test specimen containing 100 or more fibres mounted on a slide. Esch set of five test specimens shall be prepared and tested by a different technician, as described below. 7.2 Hold one end of the test Sample between the thumb and forefinger of one hand, and press the other end of the fi
34、bres against the slide by using either the other forefinger or the edge of a second slide. Pull the test Sample gently, thereby pulling out a few fibres. Repeat the process to obtain the 100 or more fibres constituting a test specimen. 7.3 Spread the parallel fibres and evenly separate them to a wid
35、th of about 25 mm, taking care to keep their centres aligned and using a dissecting needle to move them, while gently holding them with the edge of the second slide or the edge of the cover glass. Place a glass cover over the fibres and apply a drop of the sodium hydroxide Solution (4.4) to one corn
36、er. Tap the cover glass gently to facilitate wetting of all the fibres and to prevent air bubbles. 7.4 Repeat the procedure for the other four test specimens, to obtain five test specimens. Swelling of the first test specimen is then completed and the slide is ready for viewing. (See annex B for oth
37、er methods of preparing test specimens.) 8 Test procedure 8.1 Adjust the condenser of the microscope (4.1) to give critical illumination and then move it slightly to obtain a uniformly lighted field of view and a slightly exaggerated con- strast between the fibre Wall and lumen. Artificial lighting
38、gives a more constant light than daylight and is an aid to maintaining the desired level of fibre classification. 8.2 Place the first mounted slide on the microscope Stage so that the centre portions of the fibres are in the field of view. Move the slide across the Stage perpendicular to the fibre a
39、xes until the first fibre is encountered. Classify each fibre according to one of the two following Options. a) Option 1, maturity ratio : 1) dead fibre; 2) normal fibre; 3) thin walled fibre. 2 ISO 48124981 (E) b) Option 2, percent maturity : 9.2 Option 2, percent maturity 1) immature fibre; 2) mat
40、ure fibre. For each slide, the percentage of mature fibres, i.e. the percent maturity, RW, is given by the formula Classify all the fibres found on the slide and record the total number. M T x 100 8.3 where Make similar counts on the remaining slides. M is the number of mature fibres; 9 Calculation
41、and expression of resultsl) 9.1 Option 1, maturity ratio T is the total number of fibres. Calculate the mean of the ten results obtained. Calculate, for each series of fibre slides, the percentages of nor- mal and dead fibres as a ratio to the total number of fibres on the five slides. 10 Test repor
42、t The test report shall include the following particulars : For each of the two classes, calculate the mean percentage ob- tained in each series. The maturity ratio, M, is given by the formula a) a reference to this International Standard; b) the method used for preparation of the specimens (sec cla
43、use 7); c) the test result : N-D - + 0,70 200 where 1) 2) maturity ratio for Option 1; percent maturity for Option 2; N is the mean percentage of normal fibres; d) details of any operations not specified in this Interna- tional Standard or incidents likely to have had an influence D is the mean perc
44、entage of dead fibres. on the results. 1) The relationship between maturity ratio and percent maturity is given in annex C. ISO 4912-1981 (E) Annex A Typical examples of cotton fibres swollen in sodium hydroxide (This annex does not form part of the Standard.) A.l The test specified measured directl
45、y. in this international Standard necessitates constancy in visual classification because maturity is not Figures 1 to 9 illustrate typical fibres after swelling in 18 % (mlm) sodium not show the range of variations of maturity one may encounter. hydroxide Solution for Options 1 and 2. However, they
46、 can- A.2 Reference samples, whose maturity ratios have been established, may be obtained from Shirley Developments Ltd. Wilmslow Road, Didsbury, Manchester 20, England. So that a similar range of samples may be furnished, indicate the type of cotton usually tested, i.e. Egyptian, medium staple, Ame
47、rican etc. Maturity ratios of the reference samples were established on specimens more accurate than those obtained on specimens taken at random. using comb Sorter 9 the results obtained are slightly I 4 ISO 49124981 (E) Figure 1 - Dead fibre (Shows frequent convolutions and very narrow Wall) . . ,
48、.:. Figure 2 - Dead fibre (Convolutions are less frequent but wall thickness less than 1/5 of the maximum ribbon width) Figure 3 - Thin-walled fibre (Non-convoluted form, wall thickness greater than 1/5 of the maximum ribbon width) Figure 4 - Thin-walled fibre (Convoluted form with wall thickness gr
49、eater than 1/5 of the maximum ribbon width) Figure 5 - Normal fibre (Rad-like appearance; the lumen may be seen indistinctly in places but is not continuous) ISO 4912-1981 (E) Figure 6 - Normal fibre (Rod-like appearance with hardly any trace of the lumen) Figure 7 - Mature fibre Figure 8 - Immature fibre (type A) : . ., .:., : . . , :. :i :, ,. .:, , : .:./ ,.,:, y.: :v :.: : :.: . . ,:;, ,:y:y: (:. :,:y;,:$, : .:. ., :. “ .:.y . .:,:,“:yz$;g 5: : :,:, :.:.,: :; :.: 1:s; :y :,. :, . . , ,“ ,:,j. :9. . . . . . : .: .: .:, ,:,y,:;
