BS 5441-1988 Methods of test for knitted fabrics《针织品试验方法》.pdf

1、BRITISH STANDARD BS 5441:1988 Incorporating Amendment No. 1 Methods of test for Knitted fabrics UDC 677.075:677.075.3/.5/.6:001.4:620.1BS5441:1988 This British Standard, having been prepared under the directionof the Textiles and Clothing Standards Committee, was published under the authorityof the

2、Board of BSIandcomes into effect on 30September1988 BSI 08-1999 First published December1976 First revision September1988 The following BSI references relate to the work on this standard: Committee reference TCM/24 Draft for comment 87/37688 DC ISBN 0 580 16793 3 Committees responsible for this Brit

3、ish Standard The preparation of this British Standard was entrusted by the Textiles and Clothing Standards Committee (TCM/-) to Technical Committee TCM/24, upon which the following bodies were represented: Association of Consulting Scientists British Polyolefin Textiles Association British Textile E

4、mployers Association Confederation of British Wool Textiles Limited International Wool Secretariat Man-made Fibres Producers Committee Ministry of Defence SATRA Footwear Technology Centre Soap and Detergent Industry Association Society of Dyers and Colourists Society of Motor Manufacturers and Trade

5、rs Limited Textile Institute Textile Research Council Amendments issued since publication Amd. No. Date of issue Comments 6338 June 1991 Indicated by a sideline in the marginBS5441:1988 BSI 08-1999 i Contents Page Committees responsible Inside front cover Foreword ii Section 1. General 1 Scope 1 2 D

6、efinitions 1 3 Apparatus 1 4 Conditioning and testing atmosphere 3 5 Properties to be tested in accordance with existing British Standards 3 6 Assessment of barriness 3 Section 2. Weft knitted fabrics 7 Determination of weft knitted fabric construction 6 8 Determination of the number of visible wale

7、s and courses per centimetre 6 9 Determination of course length 7 10 Determination of stitch length 8 11 Determination of linear density of component yarns 8 Section 3. Warp knitted fabrics 12 Determination of warp knitted fabric construction 9 13 Determination of the number of visible wales and cou

8、rses per centimetre 9 14 Estimation of run-in 10 15 Determination of linear density of component yarns 10 Appendix A Precision of, and additional information concerning, theHatrabarriness scale 11 Figure 1 Grade of barriness scale 2 Figure 2 Viewing and illumination conditions 2 Figure 3 Barriness s

9、cale and BS grey scale spacings 4 Figure 4 The half-grade system 4 Figure 5 Rib-gaited thread path diagram system 12 Figure 6 Interlock-gaited thread path diagram system 13 Figure 7 “Prusa” system 14 Figure 8 Squared-paper system (I) 15 Figure 9 Squared-paper system (II) 16 Figure 10 Symbols for thr

10、ead path diagrams in warp knitted fabrics 17 Table 1 Minimum measuring distance 6 Table 2 Tensions 8 Table 3 Barriness, grey scale contrast and colour difference 12 Publications referred to Inside back coverBS5441:1988 ii BSI 08-1999 Foreword This British Standard has been prepared under the directi

11、on of the Textiles and Clothing Standards Committee and forms a revision of BS5441:1977 which is withdrawn. This standard provides a companion standard to BS2861 to BS2866, although this standard goes somewhat further than simple analysis. In particular, the test for assessment of barriness is inclu

12、ded and this may also be of considerable use in the evaluation of woven fabrics. Methods already published as British Standards have not been reproduced, but a list is given inclause5 of other test methods that may be of use in the assessment of knitted fabrics. The order in which the tests should b

13、e carried out is not covered by this standard since this will depend, to a large extent, on the sample size available. It is recognized that the methods given for the analysis of knitted fabrics require great skill on the part of the analyst in view of the complex nature of many such fabrics, but it

14、 is believed that the standardization of notation will go some way towards easing the difficulties. At the time of publication of this British Standard no corresponding International Standard exists. A British Standard does not purport to include all the necessary provisions of a contract. Users of

15、British Standards are responsible for their correct application. Compliance with a British Standard does not of itself confer immunity from legal obligations. Summary of pages This document comprises a front cover, an inside front cover, pages i and ii, pages1 to 18, an inside back cover and a back

16、cover. This standard has been updated (see copyright date) and may have had amendments incorporated. This will be indicated in the amendment table on the inside front cover.BS5441:1988 BSI 08-1999 1 Section 1. General 1 Scope This British Standard describes methods of test for knitted fabrics. Secti

17、on1 gives general information relevant to both warp and weft knitted fabrics; section2 specifies methods appropriate for weft knitted fabrics and section three specifies methods appropriate for warp knitted fabrics. NOTEThe titles of the publications referred to in this standard are listed on the in

18、side back cover. 2 Definitions For the purposes of this British Standard the following definitions apply. 2.1 barriness or barr regularly repeating stripiness in textiles 2.2 barry exhibiting barriness 2.3 grade one of five members of the scale (see3.7), each exhibiting a different degree of bar/bac

19、kground contrast 2.4 half-grade an imaginary contrast midway between those exhibited by two adjacent grades 2.5 rating or barriness rating the number of the grade or half-grade assessed visually as exhibiting a degree of contrast between bars and background similar to that on the fabric being compar

20、ed with the scale 3 Apparatus 3.1 Counting glass, the aperture width of which shall be2 0.005cm at all places. The thickness of the base plate at the edges of the aperture shall not exceed0.1cm. Other suitable apparatus may be used. 3.2 Ruler 3.3 Dissecting needles, scissors and razor blades 3.4 Bal

21、ance, capable of weighing to an accuracy of0.1mg. 3.5 Crimp tester 3.6 Course length tester, consisting of a weighted clamp and a rigid base-board adapted for mounting vertically on which are mounted an appropriate number of freely rotating pulleys so positioned that the yarn can be wound round them

22、 in a zig-zag manner, and a series of locations for a yarn clamp labelled to show the distance from the clamp to the zero point of a metric ruler. When the yarn is attached to the clamp and wound round the pulleys, the length indicated on the ruler by the weighted clamp is added to that indicated on

23、 the appropriate location in use to give the total length of yarn. Alternatively an electronic course length tester consisting of a measuring wheel with electronic pick ups, a digital display and a tensioning device as well as a hold down device for the specimen of circular knitted fabric may be use

24、d. 3.7 The Hatra barriness scale, which consists of five numbered black frames, each with a grey card and a hole of equal size. Grade5 is bar-free, grades4 to1 are progressively more barry. A grade is illustrated inFigure 1 and information on the precision of the method and care of the scale is give

25、n inAppendix A. The external dimensions of the black frames are355mm 250mm. The grey cards (i.e. the actual photographs illustrating the various degrees of contrast between bars and background) are100mm 118mm and the adjacent holes are the same dimensions. Each grey card has parallel lines0.75mm thi

26、ck and9mm apart 1) . 3.8 Light source, preferably artificial daylight fluorescent tubes 2) . The tubes shall be changed after2000h to3000h use because of diminished ultraviolet emission. NOTEThe preferred light intensity is at least810lux, likely to be available approximately300mm from one or1000mm

27、from two65/80W tubes of the previously mentioned type. A preferred viewing arrangement is illustrated inFigure 2, in which the tubes are at such an angle that the fabric receives most of the light from the tube areas nearest to it at an angle of45 and the fabric is viewed from a distance of300mm. Al

28、though the frames of the barriness scale shield the eyes from the surrounding field, it is good policy for viewing areas to be matt neutral grey. Too much black can be depressing and tiring; gloss paint causes glare and fatigue. 1) The repeat distances and thickness are typical of 24-feeder interloc

29、k fabric, which is both popular and prone to barriness. However, the use of the scale is not specifically tied to any type of fabric. 2) These are better than previous attempts to match daylight, particularly with respect to red rendering and the content of ultraviolet radiation (seeBS950-1).BS5441:

30、1988 2 BSI 08-1999 Table and tube mounting (650mm above it) are both at22.5 to the horizontal. The two tubes are within180mm of the rear. The “stop” on the table is500mm from the rear and130mm from the front, which is850mm from the floor. At the front of the mounting there is a140mm high vertical an

31、ti-glare shield,300mm proud of the wall. The whole area is well shielded from daylight. Figure 1 Grade of barriness scale Figure 2 Viewing and illumination conditionsBS5441:1988 BSI 08-1999 3 Since special provision of the preferred conditions is required, it may prove convenient to use other condit

32、ions, and these should be reported. For instance, it is possible to use commercial colour matching equipment 3) . This reverses the angles inFigure 2 and it is supplied with the recommended tube. Alternative lighting is also possible. This could be an ultraviolet tube, perhaps useful if gross yarn m

33、ixing, for instance polyester with nylon, is suspected and ecru fabric is being assessed. Daylight can be used, but is more variable than the tube, even if north light only is used, and it may not always be bright enough for reliable assessments. CAUTION. Ratings may vary with conditions of use. The

34、 recommendations in this standard give maximum agreement between observers. Other conditions can be used in special circumstances. If this is the case, these should be agreed, specified and recorded. 4 Conditioning and testing atmosphere The standard temperate atmosphere for conditioning and testing

35、 textiles as defined in BS1051,i.e. relative humidity of65 2% and a temperature of20 2 C, shall be used. Perform all tests in the standard temperate atmosphere for testing textiles. 5 Properties to be tested in accordance with existing British Standards A number of properties of knitted fabrics can

36、be tested in accordance with other appropriate British Standards, which include the following. BS 1930 for the determination of width of woven or knitted fabrics when relaxed at zero tension. BS 1931 for the determination of length of woven or knitted fabrics when relaxed at zero tension. BS 1955 fo

37、r the determination of dimensional changes of wool-containing knitted fabrics during washing. BS 2471 for testing the mass per unit length and per unit area of woven or knitted fabrics. BS 2544 for the determination of thickness of textile fabrics. BS 2864 for the determination of twist in yarn remo

38、ved from fabric. BS 4294 for testing the stretch and recovery properties of fabrics. BS 4768 for the determination of the bursting strength and bursting distension of fabrics. BS 5811 for determination of pilling and change of appearance of fabrics 6 Assessment of barriness 6.1 General Regularly rep

39、eating stripiness in textiles is known as barriness or barr. Goods from all fibres can be affected, but most cases of commercial importance have involved weft knitted multifeeder fabrics from synthetic fibres. These fabrics may be barry because yarns differ in dyeability, physically, geometrically,

40、or in all of these ways. Yarns in different courses may differ in knitting, in crimp frequency or in crimp configuration. A false-twist processing variation may affect both crimp and dyeability. Yarn may be faulty owing to chemical variation or different draw ratios in producer yarn or owing to heat

41、er-temperature, twist, or tension variation in false-twisting. A very small proportion of faulty yarn can lead to large proportions of faulty fabric, the more so the larger the number of feeders in a multifeeder knitting machine 4) . This standard specifies a method enabling barriness to be assigned

42、 reliably and quickly to any one of nine half-grades, from bar-free to very bad bars, by means of a scale of five grades. After evaluation of the various methods of producing scales for the assessment of barriness 5) , a photographic technique was found to be the most reliable and reproducible. The

43、scale specified is not a series of photographs of any type of textile fabric. It is purely a series of line contrasts produced by differential exposure of photographic paper to light. The scale is intended primarily for rating repeating contrast, whether on weft knitted fabric or on warp knitted, wo

44、ven, or bonded-fibre material. The less regularly repeating and the shorter term (i.e.streaky rather than barry) the contrast is, the less tailor-made the scale is for assessing it. The suitability of the scale for short-term variations, say warp streaks in warp knitted fabrics or woollen yarn spinn

45、ing variations in weft knitted or woven fabrics, has not been investigated in detail. The grades of the scale illustrate different degrees of contrast and these are compared with the constrast in the fabric being assessed, regardless of any difference in width and frequency of bars in fabric and sca

46、le grade. 3) For details of sources of supply of suitable colour matching equipment apply to Enquiry Section, BSI, Linford Wood, Milton KeynesMK146LE. 4) Morris, W.J. and Roberts, A.S.J. Text. Inst., 1966, 57,219 Hutchings, D.M. Hosiery Res. Bull., 1967, 8, 13. 5) Jaeckel, S.M., Hatra Production Not

47、e No. 17, November 1976.BS5441:1988 4 BSI 08-1999 Considering interpretation, no single rating, like3or34, is an always valid limit of fabric suitability; such limits will vary with fabric construction, colour, end-use, end-use orientation, area visible in end-use, viewing conditions and illuminatio

48、n. More barry (lower rating) fabrics may be acceptable for small end-use areas, particularly if not often viewed obliquely. Compared with the scale specified in BS1006, section A02, the contrasts exhibited on the barriness scale are so compressed that the worst degree of barriness exhibited, grade1

49、of the barriness scale, is, objectively, approximately equivalent to the contrast of grade3 of the grey scale. Barriness objectively equivalent to grade1 or grade2 of the grey scale was felt to be so bad from a practical point of view that neither these grades nor the distinction between them were of interest to barry fabrics. The relative spacings are approximately as shown inFigure 3. Figure 4 illustrates how to rate bar/background contrasts intermediate between two adjacent grades. With a contrast greater than grade3, but less than