1、BRITISH STANDARD BS 946:1970 Method for the Designation of yarnsBS946:1970 This British Standard, having been approved by the Textile Divisional Council was published under the authority of the Executive Board on 14 September1970 BSI 10-1999 First published March 1941 First revision May 1952 Second
2、revision September 1970 The following BSI references relate to the work on this standard: Committee reference T/8 Draft for comment 69/21066 ISBN 580 06382 8 Co-operating organizations The Textile Divisional Council, under whose supervision this British Standard was prepared, consists of representat
3、ives from the following Government department and scientific and industrial organizations: British Railways Board Consumer Council Cotton Industry Standards Committee Jute Industry Standards Committee Linen Industry Standards Committee London Transport Board Man-made Fibres Industry Standards Commit
4、tee Ministry of Defence* Ropes and Cordage Industry Standards Committee Silk Industry Standards Committee Society of Dyers and Colourists* Textile Institute* Textile Machinery Industry Standards Committee Trades Union Congress Wool Industry Standards Committee The Government department and organizat
5、ions marked with an asterisk in the above list, together with the following, were directly represented on the committee entrusted with the preparation of this British Standard: British Launderers Research Association British Man-made Fibres Federation Committee of Directors of Textile Research Assoc
6、iations Cotton Silk and Man-made Fibres Research Association Hosiery and Allied Trades Research Association International Federation of Cotton and Allied Textile Industries Scottish Textile Research Association Wool Industries Research Association Amendments issued since publication Amd. No. Date Co
7、mmentsBS946:1970 BSI 10-1999 i Contents Page Co-operating organizations Inside front cover Foreword ii 1 Scope 1 2 Definitions and symbols 1 3 Yarn designation based on the linear density of the single yarn (single to fold designation) 4 4 Yarn designation based on the resultant linear density (fold
8、 to singledesignation) 6 5 Abbreviated designations 7 Figure 1 S and Z twists 3 Figure 2 Directions of twist in folded and cabled yarns 3BS946:1970 ii BSI 10-1999 Foreword This standard makes reference to the following British Standard: BS947, Specification for a universal system for designating lin
9、ear density of textiles (Tex System). This British Standard is in accordance with the ISO Recommendation R1139, “Designation of yarns”, which has received substantial support and in the preparation of which the UnitedKingdom has played an active part. The first and second editions of BS946, issued i
10、n1941 and1952, provided for designations beginning with a description of the single yarn components and ending with particulars of the final product. The limitations of this order of presentation are many and BS946 was not widely supported by the textile industry. Consequently the responsible Textil
11、e Institute Committee prepared a new draft method whereby designations of all yarns began with a description of the final product of the yarn manufacturing process, thus stressing those characteristics of a yarn that are of most importance to the majority of users and facilitating the abbreviation o
12、f yarn designations. This method was circulated for comment in1960 but was not developed further because simultaneously alternative proposals for the designation of yarn structure were under consideration by the Technical Committee on Textiles of the International Organization for Standardization. I
13、t was agreed to await developments within ISO and to adopt the recommendations agreed internationally. This decision is implemented by publication of the present standard. The general introduction of the Tex system for expressing the linear density of yarns is an additional incentive for standardiza
14、tion of the designation of yarn structure. In designating yarns it has been customary, and it remains desirable, to reflect in a condensed form details of the components of a yarn including values of the linear densities, directions and amounts of twist, number of folds, etc., of these components an
15、d/or characteristics of the yarn resulting from this construction, such as its linear density indicated as resultant linear density. The resultant linear density of folded and/or cabled yarns will generally differ from the sum of the linear densities of the components and, even when starting from th
16、e same component yarns, using the same direction and amount of twist, number of folds, etc., yarns with different resultant linear densities may be produced due to differences in conditions during manufacturing, such as yarn tensions, types of machine used, moisture content of the yarns, atmospheric
17、 conditions, etc. A yarn designation serves two purposes: 1) It is used as a general indication of a yarn; in this case the values for linear densities, amounts of twist, folds, etc., used in the yarn designation will be referred to as nominal values; and 2) it may be used for reporting the result o
18、f an analysis of a yarn; in this case the values derived from an authorized testing procedure for linear densities, amounts of twist used in the yarn designation will be referred to as actual values. Attention is drawn to the fact that the application of the designation of yarns in the Tex System do
19、es not affect existing commercial practices in the trade. Values of linear density and amount of twist used in commercial transactions are nominal unless explicitly stated as being actual. Nominal linear densities and amounts of twist are subject to tolerances, the numerical values of which are usua
20、lly agreed in the various branches of the textile industry or directly between the seller and the buyer.BS946:1970 BSI 10-1999 iii In this British Standard two methods for the designation of yarns are described, namely: 1) Yarn designation starting from the linear density of the single yarn. It may
21、be referred to as single to fold designation. 2) Yarn designation starting from the linear density of the resultant yarn. It may be referred to as fold to single designation. The symbols used in both systems are identical. The differences are in the order of presentation, the use of the multiplicati
22、on sign () in the single to fold designation, and of the solidus (/) in the fold to single designation. A British 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 Stand
23、ard does not of itself confer immunity from legal obligations. Summary of pages This document comprises a front cover, an inside front cover, pages i to iv, pages1to8, an inside back cover and a back cover. This standard has been updated (see copyright date) and may have had amendments incorporated.
24、 This will be indicated in the amendment table on the inside front cover.iv blankBS946:1970 BSI 10-1999 1 1 Scope This British Standard describes two methods of indicating the composition of yarns, whether single, folded, cabled or multiple wound. The designation comprises linear density indicated i
25、n the Tex System, number of filaments in filament yarns, direction and amount of twist, and number of folds. This designation has not yet been extended to some special kinds of yarns, e.g.to fancy yarns, textured or bulked yarns or yarns produced by wrapping a textile, or non-textile material, round
26、 a core; nor does it deal with other features such as constituent fibres, after-treatment and type of package. 2 Definitions and symbols 2.1 For the purposes of this British Standard the following definitions apply: 2.1.1 yarn a general term covering all the specific types and structures described b
27、elow 2.1.2 single yarn 1) the simplest continuous strand of textile material composed of one of the following: a) A number of discontinuous fibres, held together generally by twist. Such yarns are described as spun yarns. b) One or more continuous filament(s). Twist may be absent (zero twist yarn) o
28、r present. Such yarns are described as filament yarns. c) One filament only. Such yarns are described as monofilaments. d) Two or more filaments. Such yarns are described as multifilaments. 2.1.3 multiple wound yarn yarns formed from two yarns or more wound together but not twisted together 2.1.4 fo
29、lded yarn general term designating yarn formed by twisting together two or more single yarns in one folding operation a) Twofold yarn. Folded yarn formed from two single yarns twisted together. b) Multifold yarn. General term designating folded yarns consisting of more than two single yarns twisted
30、together in one folding operation. 1) For the present this definition does not include polymer tape yarns. i) Threefold yarn. Folded yarn formed from three single yarns twisted together in one single operation. ii) Fourfold yarn. Folded yarn formed from four single yarns twisted together in one sing
31、le operation.BS946:1970 2 BSI 10-1999 2.1.5 cabled yarn NOTEIn the rope and fishing industries a cabled yarn is generally made of single filaments twisted together, each receiving an additional twist during the twisting operation, which is known as cabling. 2.1.6 yarn designation condensed technical
32、 description of a yarn, comprising some or all of the following: a) linear density (see2.1.7); b) number of filaments; c) direction of twist at each twisting operation; d) amount of twist at each twisting operation; e) number of components in folding; f) number of components in cabling. 2.1.7 linear
33、 density mass per unit length of a yarn. It is expressed in tex or its multiples or submultiples 2.1.8 resultant linear density the linear density of the final product resulting from twisting, folding or cabling operations NOTE 1When supplementary chemical or physical treatments have been applied to
34、 the final product and their effect has been incorporated in the resultant linear density, this should be specifically stated. NOTE 2The final product may be influenced by various manufacturing operations to such an extent that the use of the resultant linear density may become preferable as a basis
35、 for manufacturing calculations. 2.1.9 direction of twist the direction of twist at each stage of manufacture is indicated by the capital letter S or Z as follows a) A single yarn has S twist if, when it is held in the vertical position, the fibres inclined to the axis of the yarn conform in directi
36、on of slope to the central portion of the letter S (seeFigure 1). b) A single yarn has Z twist if, when it is held in the vertical position, the fibres inclined to the axis of the yarn conform in direction of slope to the central portion of the letter Z (seeFigure 1). c) In folded and cabled yarns t
37、he direction of the twist is that of the appropriate component (seeFigure 2) when the yarn is held in the vertical position. two or more folded yarns (or alternatively folded and single yarns) twisted together in one or more folding operationsBS946:1970 BSI 10-1999 3 Figure 1 S and Z twists Figure 2
38、 Directions of twist in folded and cabled yarnsBS946:1970 4 BSI 10-1999 2.1.10 amount of twist the number of turns per metre of the twisted yarn 2.1.11 nominal an adjective which indicates that a value is approximate and subject to the tolerances agreed in normal commercial practice or between the b
39、uyer and the seller NOTE 1The nominal linear density of single yarns in the Tex System should be chosen for the different types of textiles from the special lists agreed by the various sections of the industry. See also BS947, “Specification for a universal system for designating linear density of t
40、extiles (Tex System)”. NOTE 2Nominal linear density usually refers to the grey (unprocessed) yarn; in certain sections of the textile industry, however, the same nominal linear density is used for chemically processed (bleached, dyed, etc.) yarns as for the original unprocessed yarns. 2.1.12 actual
41、an adjective indicating a value which results from an authorized testing procedure 2.2 As a means of indicating some of the items in2.1 the following symbols are used: 1) R. Symbol for resultant linear density to be put before its numerical value. 2) f. Symbol for filaments to be put before the numb
42、er of filaments. 3) t0. Symbol for zero twist. 3 Yarn designation based on the linear density of the single yarn (single to fold designation) In this form of designation give details of the characteristics of the different types of yarn in the order they are set out below. The resultant linear densi
43、ty may be given as supplementary information, in which case it is separated from the preceding part by a semicolon (see, for example,3.1.3). 3.1 Single yarns 3.1.1 Spun yarns 1) linear density 2) direction of twist 3) amount of twist Example.40 tex Z660 3.1.2 Monofilaments without twist 1) linear de
44、nsity 2) symbol f 3) Figure 1 4) symbol t0 Example.17 dtex f1 t0 3.1.3 Twisted monofilaments 1) linear density of the monofilament without twist 2) symbol f 3) Figure 1 4) direction of twist 5) amount of twist Example. 17 dtex f1 S800; R17.4 dtexBS946:1970 BSI 10-1999 5 3.1.4 Multifilaments without
45、twist 1) linear density 2) symbol f 3) number of filaments laid together 4) symbol t0 Example. 133 dtex f40 t0 3.1.5 Twisted multifilaments 1) linear density 2) symbol f 3) number of filaments twisted together 4) direction of twist 5) amount of twist Example.133 dtex f40 S1000; R136 dtex 3.2 Multipl
46、e wound yarns 3.2.1 Multiple wound yarns having similar components 1) designation according to3.1 of the single yarn used 2) multiplication sign, 3) number of single yarns laid together 4) symbol t0 Example.40 tex S155 2 t0 3.2.2 Multiple wound yarns having dissimilar components 1) designation accor
47、ding to3.1 of the single yarns used, connected by the sign+and put in brackets 2) symbol t0 Example. (25 tex S420+60 tex Z80) t0 3.3 Folded yarns 3.3.1 Folded yarns having similar components 1) designation according to3.1 of the single yarn used 2) multiplication sign 3) number of single yarns twist
48、ed together 4) direction of folding twist 5) amount of folding twist Example.34 tex S600 2 Z400; R69.3 tex 3.3.2 Folded yarns having dissimilar components 1) designation according to3.1 of the single yarns used, connected by the sign+ and put in brackets 2) direction of folding twist 3) amount of fo
49、lding twist Example. (25 tex S420+60 tex Z80) S360; R89.2 tex 3.4 Cabled yarns 3.4.1 Cabled yarns having similar components 1) designation according to3.3 of the folded yarn used 2) multiplication sign 3) number of folded yarns cabled together 4) direction of cabling twist 5) amount of cabling twist Example.20 tex Z700 2 S400 3 Z200; R132 texBS946:1970 6 BSI 10-1999 3.4.2 Cabled yarns having dissimilar components 2) 1) designation according to3.1 for the single yarns according to3.3 for the folded yarns connected by the sign+ and put in brackets 2) dire
