1、CEN ENJ1049-2 93 = 3404589 0058189 279 EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN 1049-2 December 1993 UDC 677.064 : 677.017.353 Descriptors: lkxtiles, woven fabrics, tests, determination, numbers, yarns English version Textiles - Woven fabrics - Construction - Methods of analysis - Part 2
2、: Determination of number of threads per unit length (IS0 7211-2 : 1984 modified) Textiles - Tissus - Construction - Mthodes danalyse Partiez: Dtermination du nombre de fils par unit de longueur Lngeneinheit (IS0 7211-2 : 1984 modifie) Textilien - Gewebe - Untersuchungsverfahren - %il 2: Bestimmung
3、der Anzahl der Fden je (IS0 7211-2 : 1984 Gendert) This European Standard was approved by CEN on 1993-12-16. CEN members are bound to comply with the CENXENELEC Internal Regulations which stipulate the conditions for giving this European Standard the status of a national standard without any alterat
4、ion. Up-to-date lists and bibliographical references concerning such national standards may be obtained on application to the Central Secretariat or to any CEN member. This European Standard exists in three official versions (English, French, German). A version in any other language made by translat
5、ion under the responsibility of a CEN member into its own language and notified to the Central Secretariat has the same status as the official versions. CEN members are the national standards bodies of Austria, Belgium, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg,
6、Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and United Kingdom. CEN European Committee for Standardization Comit Europen de Normalisation Europisches Komitee fr Normung Centrai Secretariat: rue de Stassart 36, B-1050 Brussels O 1993 Copyright reserved to CEN members Ref. No. EN 1049-2
7、: 1993 E CEN EN*cL049-2 93 = 3404587 0058L70 T90 Page 2 EN 1049-2 : 1993 Foreword This European Standard has been taken over by CEN/TC 248, Textiles and textile products, from the work of ISO/TC 38, Textiles, of the International Organization for Standardization (ISO). This European Standard is base
8、d on IS0 7211-2 : 1984 This European Standard shall be given the status of a national standard, either by publication of an identical standard, either by endorsement, at the latest by June 1994, and conflicting national standards shall be withdrawn at the latest by June 1994. The standard was approv
9、ed and in accordance with the following CENXENELEC Internal Regulations, the following countries are bound to implement this European Standard: Austria, Belgium, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland,
10、 United Kingdom. CEN ENrI1049-2 93 3404589 0058191 927 H Less than 10 10 to 25 25 to 40 More than 40 Page 3 EN 1049-2 : 1993 10 5 3 2 Textiles - Woven fabrics - Construction - Methods of analysis - Part 2: Determination of number of threads per unit length Less than 100 50 to 125 75 to 120 More than
11、 80 1 Scope and field of application This part of IS0 7211 specifies three methods for the deter- mination of the number of threads per centimetre in woven fabrics. Any of the three methods may be used, the choice depending on the character of the fabric. However, in case of dispute method A is reco
12、mmended. Method A: Dissection of fabric, suitable for all fabrics. This is the most laborious method but has fewer limitations than the others; in particular, it is the only one that is really suitable for the examination of certain folded structures and other complicated weaves. Method B: Counting
13、glass, suitable for woven fabrics with more than 50 threads per centimetre. Method C: Traversing thread counter, suitable for all fabrics. Greater than 0.5 1,0 to 0,4 0,7 to 0,4 Less than 0.6 Where the number of threads per centimetre is low, it may be convenient to express the results as the number
14、 of threads per decimetre. NOTE - Methods using parallel line gratings and tapered line gratings have been given in the annex for information. These methods have not been considered accurate enough to be used as standard test methods but can be used to give rough and ready estimates for routine test
15、ing. 2 Reference IS0 139, Textiles - Standard atmospheres for conditioning and testing. 3 Principle Three methods of determining the number of threads per centimetre are specified, any of which may be used, the choice depending on the character of the fabric. The prin- ciples are as follows: Method
16、A: A section of fabric of dimensions in accor- dance with those given in clause 4 is dissected and the number of threads counted. The threads that are to be counted are preferably short, 1 or 2 cm being suitable. Method B: The number of threads visible within the aperture of a specified counting gla
17、ss is determined. Method C: The number of threads per centimetre of the fabric is determined with the aid of a traversing thread counter. 4 Minimum measuring distance Use the appropriate minimum measuring distance specified in the table. Table - Minimum measuring distance per centimetre Accuracy in
18、0.5 thread) of threads For the method A, take test pieces containing at least 100 threads. For narrow fabrics having a width of 10 cm or less, count all warp threads including the selvedge ends and express the result as threads per full width. When fabrics are patterned by broad areas of higher or l
19、ower density of thread spacing, select test specimens containing at least one weave repeat (see clause 10). 5 Conditioning and testing atmosphere The atmosphere for preconditioning, conditioning and testing shall be as specified in EN 20139. 6 Test specimens No specially prepared specimens are requi
20、red except for method A (see 7.21, but count the threads at not less than five different points selected to represent the fabric as fully as poss- ible. Expose the fabric or specimens to the standard at- mosphere for testing for at least 16 h before making the test. CEN EN*l1049-2 93 m 3404589 00581
21、92 863 Page 4 EN 1049-2 : 1993 7 Method A - Dissection of fabric 7.1 Apparatus 7.1.1 Clamp, holding two short pins parallel and with their points being within k 0,02 cm of the minimum measuring distance specified in clause 4. Alternatively, when a clamp is not available, 7.1.2 Two dissecting needles
22、 and 7.1.3 Heavy steel rule. whole repeats in the measuring distance, plus the remaining in- dividual threads. Determine the number of threads in a repeat by analysis of the weave or dissection of the fabric. Count the number of warp threads, or the number of weave repeats, or the number of warp thr
23、ead units and fractions of a unit bounded by the appropriate pair of opposite sides of the aperture. Repeat with one of the edges of the aperture parallel to the weft threads, and count the number of weft threads or weave repeats or number of weft thread units in a similar manner. If the face of the
24、 fabric is composed mainly of one set of threads, as with certain twills, sateens, etc, it may be found easier to count on the back of the fabric, where the weave design is more readily recognizable. 7.2 Procedure 9 Method C - Traversing thread counter Take five specimens at random (see clause 6) 0.
25、4 to 0,6 cm longer than the minimum measuring distance specified in clause 4 and sufficiently wide to facilitate handling. Take care not to disturb the disrribution of threads, especially in a loosely woven fabric. Pass the pins in the clamp (7.1.1) through a specimen 0,2 to 0,3 cm from each end. Re
26、move the shorter threads (those in the direction to be counted) from the specimen outside the two pins. so that the measuring distance of fabric between the pins remain. Then remove the short threads from the specimen and count them. Count any threads impaled on a pin as half a thread. It is usually
27、 convenient to employ a pair of pointed forceps to remove the threads. The threads may be arranged in groups of ten for convenience in counting. An approved alternative method where a clamp is not available is to insert two dissecting needles (7.1 2) the required distance apart by sliding their poin
28、ts down the appropriate graduation marks of a heavy steel rule (7.1.3) placed on edge. 8 Method B - Counting glass 8.1 Apparatus 8.1.1 Counting glass, the aperture width of which shall be 2 k 0,005 cm or 3 I 0,005 cm at all places. The thickness of the base plate at the edges of the aperture shall n
29、ot exceed 0.1 cm. 8.2 Procedure Use a measuring distance in accordance with clause 4. Lay the fabric flat on a horizontal surface and place the count- ing glass (8.1.1) on the fabric so that one of the edges of its aperture is parallel to the warp threads. In some fabrics, it is possible to see and
30、count every thread. If this is not possible, weave repeats may be counted. Select a thread in the weave repeat which can be identified readily and position the counting glass so that this thread is adjacent to one side of the aperture of the counting glass. Count the number of 9.1 Apparatus 9.1.1 Tr
31、aversing thread counter, incorporating a low- power microscope, of X 4 to X 20, mounted so that it can be traversed by means of a screw over a graduated base suffi- ciently long to meet the minimum measuring distance re- quirements of clause 4. Types with an index line in the eyepiece or a pointer t
32、raversing with and visible through the microscope are equally suitable. 9.2 Test procedure Use a measuring distance in accordance with clause 4. Lay the fabric flat on a horizontal surface and place the thread counter (9.1,l) upon it in such a way that when the screw is turned the microscope moves a
33、cross the fabric in a direction that is either parallel to the warp or parallel to the weft, depend- ing on which set of threads is being counted. Count the number of threads over the appropiate minimum measuring distance. In some fabrics it is possible to see and count every thread passed by the po
34、inter or index line as it moves across the fabric. If this is not possible, weave repeats may be counted. Begin counting from a thread in the weave repeat which can be read- ily identified. Count the number of whole repeats in the measuring distance, plus the remaining individual threads. Determine
35、the number of threads in a repeat by analysis of the weave or dissection of the fabric. If the face of the fabric is composed mainly of one set of threads, as with certain twills, sateens, etc., it may be found easier to count on the back of the fabric, where the weave design is more readily recogni
36、zible. 10 Calculation and expression of results Calculate the number of threads per centimetre. Quote the mean of individual results for each direction, that for the warp threads as ends per centimetre and that for the weft as picks per centimetre. The number of threads per square centimetre is give
37、n by the sum of the mean ends and picks per centimetre. CEN EN*3049-2 93 3Li04589 0058393 7TT Page 5 EN 1049-2 : 1993 1 When fabrics involving fancy weaving are patterned by small e) the number of measurements made; areas of two or more types of threads in warp and weft directions, count the number
38、of threads of each type in a periodic pattern and then calculate the number of threads per 1 O crn after measuring the periodicity and repeat pattern. 11 Test report The test report shall include the following particulars: a) a reference to this International Standard (IS0 7211/2); b) the standard a
39、tmosphere used (temperate or tropical); ci the actual method used (A, B or Ci; d) the measuring distance used; fi the number of warp ends per centimetre and weft picks per centimetre and the mean value of warp ends per centimetre and weft picks per centimetre. If the fabric is pat- terned by broad a
40、reas of greater and lower density, and if required, this information can be given for each different portion of the pattern. Where the number of threads is low, it is permissible to ex- press and report the results as the number of threads per decimetre. For narrow fabrics (see clause 41, report the
41、 results as the number of threads per full width; g) if required, the number of threads per square centimetre (or square decimetre); h) details of any deviation from the method. CEN EN*1049-2 93 3404589 0058394 b3b Page 6 EN 1849-2 1993 Annex Method using taper and parallel line gratings (included f
42、or information purposes.) A.l This method is suitable only for fabrics where thread patterns yield interference bands that are readily visible. Method D - Parallel-line grating When fabrics are patterned by broad areas of greater and lower density of thread spacing, it may be desirable tc record the
43、 number of threads per centimetre in each different portion of the pattern. A.l.l Principle A.2 Method E - Taper-line gratings The number of interference bands produced when the parallel line grating is placed on the fabric is determined. This method is suitable only for fabrics where thread pattern
44、s yield interference bands that are readily visible. A.1.2 Apparatus A.1.2.1 Parallel line grating, with a length of 10 or 20 cm A.2.1 Principle and with about 5 % more or less lines per centimetre than there are threads per centimetre in the cloth to be tested. if several gratings of different gaug
45、es are available, select the most suitable by trial. The number of threads is determined by observation of the interference pattern produced when a taper-line grating is placed on the fabric. It is essential that the lines on the grating are straight and parallel. The average number of lines per cen
46、timetre over the whole grating shall be known to 0,1, and the average number of lines per centimetre at either edges of known length shall not differ from the general average by more than 0,15 %. A.1.3 Procedure Place the grating selected as most suitable on the fabric with its lines parallel to the
47、 threads to be counted. If a suitable grating has been chosen, a number of bands parallel to the edge of the grating as shown in figure 1 will be seen. Count the number of these bands along the middle of the grating and divide by the length of the grating in centimetres, to obtain the mean number of
48、 bands per centimetre. Either add the number of bands per centimetre to the number of lines per centimetre of the grating, or subtract the number of bands per centimetre from the number of lines per centimetre of the grating, in accordance A.2.2 Apparatus A.2.2.1 Taper-line grating, consisting of di
49、verging lines disposed symmetrically between two parallel scales 2.5 cm apart, so that they cut off equal intercepts along any line at right angles to the axis of symmetry. Corresponding gradua- tions on the scales are opposite one another, and the gradua- tions indicate the number of units, consisting of a line and a space, counted in a straight line from a graduation on one scale to the corresponding graduation on the other. The graduations indicate whole numbers with an accuracy of 0,5 %. The divergence of the lines should be such that the greatest and least values of lines pe
