BS 4611-1989 Methods of test for polyolefin tape yarns《聚烯烃扁丝的试验方法》.pdf

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1、BRITISH STANDARD BS 4611:1989 Methods of test for Polyolefin tape yarnsBS4611:1989 This British Standard, having been prepared under the directionof the Textiles and Clothing Standards Policy Committee, was published underthe authority of the BoardofBSI and comes intoeffecton 29September1989 BSI 12-

2、1999 First published July 1970 First revision April 1976 Second revision September 1989 The following BSI references relate to the work on this standard: Committee reference TCM/24 Draft for comment 87/43811 DC ISBN 0 580 17519 7 Committees responsible for this British Standard The preparation of th

3、is British Standard was entrusted by the Textiles and Clothing Standards Policy Committee (TCM/-) to Technical Committee TCM/24, upon which the following bodies were represented: Association of Consulting Scientists British Nonwovens Manufacturers Association British Polyolefin Textiles Association

4、British Textile Employers 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 Manufa

5、cturers and Traders Limited Textile Institute Textile Research Council Amendments issued since publication Amd. No. Date of issue CommentsBS4611:1989 BSI 12-1999 i Contents Page Committees responsible Inside front cover Foreword ii 1 Scope 1 2 Definitions 1 3 Materials 1 4 Selection of test specimen

6、s 1 5 Calculation and expression of results 1 6 Atmosphere for conditioning and testing 1 7 Determination of linear density 1 8 Determination of width 2 9 Determination of thickness 2 10 Determination of twist 2 11 Determination of breaking strength, extension, tenacity and elastic modulus 3 12 Dete

7、rmination of colour fastness to light 3 13 Determination of heat shrinkage using an oil bath 3 14 Determination of heat shrinkage using hot air 5 Figure 1 Measurement of width 4 Figure 2 Method for determining elastic modulus 4 Publications referred to Inside back coverBS4611:1989 ii BSI 12-1999 For

8、eword This British Standard has been prepared under the direction of the Textiles and Clothing Standards Policy Committee and forms a revision of the1976edition which is withdrawn. The principal change introduced into this revision is that BS1932-1is used for determination of tensile properties, and

9、 an additional method for determination of heat shrinkage using hot air has been added. At the time of preparation 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 British Sta

10、ndards 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 6, an inside back cover and a back cover. This

11、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.BS4611:1989 BSI 12-1999 1 1 Scope This British Standard describes methods of test for polyolefin tape yarns and derived yarns used for text

12、ile applications other than cordage. NOTEThe titles of the publications referred to in this standard are listed on the inside back cover. 2 Definitions For the purposes of this British Standard the following definitions apply. 2.1 tape yarn flat yarn having a high ratio of width to thickness, manufa

13、ctured by film or spinneret extrusion processes 2.2 derived yarn yarn derived from a tape yarn, e.g.by twisting, fibrillation, folding 2.3 package a length of yarn in a form suitable for handling, storing, processing,etc. (e.g.skein, cake, cop, pirn, bobbin, spool, tube) 3 Materials The tests relate

14、 to yarns produced from: a) polypropylene complying with BS5139; b) polyethylene complying with BS3412; c) copolymers propylene and ethylene and physical mixtures of these olefin polymers. NOTEAttention is drawn to the fact that polyolefins are liable to actinic degradation when exposed to strong su

15、nlight. When the possibility of actinic degradation is a significant factor the degree of stabilization should be agreed between the purchaser and the supplier. 4 Selection of test specimens 4.1 Sampling of packages From each consignment take at random five packages per tonne or part thereof with a

16、minimum of five packages. 4.2 Test specimens Take one test specimen for each test from each package in the test sample. 5 Calculation and expression of results For each type of test, calculate the arithmetic mean and coefficient of variation of all the test results relating to the consignment. 6 Atm

17、osphere for conditioning and testing Use an atmosphere having a temperature of20 2 C for testing. In cases of dispute carry out the tests in the standard temperate atmosphere for testing textiles defined in BS1051,i.e.a relative humidity of65 2% and a temperature of20 2 C. 7 Determination of linear

18、density 7.1 General This test method is based on that given in BS2010. It is applicable to polyolefin tape yarns which have been conditioned for24h in the atmosphere described in clause6. The method describes the determination of linear density in tex units of yarns from packages in: a) the conditio

19、ned state (method A); b) free from added matter in the conditioned state (method B). 7.2 Principle Test skeins of known length are reeled and weighed either in the conditioned state or in the conditioned state after removal of added matter. From the known length and the mass of each skein the linear

20、 density of the yarn in tex units is calculated. 7.3 Apparatus 7.3.1 Wrap reel, of girth1m. Reels of other girths may be used provided that the nominal girth is not less than900mm. The reel may be hand driven or power driven and shall be fitted with an adjustable tensioning device and with a travers

21、ing device to prevent excessive bunching of the yarn during reeling. 7.3.2 Balance, accurate to 0.2%. 7.4 Procedure 7.4.1 Reeling of test skeins. From each package in the sample, reel a test skein of10turns onto the wrap reel, using sufficient tension to ensure that the skein girth is within0.25% of

22、 the actual girth of the wrap reel, drawing the yarn from the package in the manner in which it would normally be drawn during the next stage of manufacture or processing. In cases of dispute take50turns on the wrap reel. 7.4.2 Weighing test skeins (Method A). Condition the test skeins for24h in an

23、atmosphere as described inclause6 and weigh each of the skeins to an accuracy of0.2%.BS4611:1989 2 BSI 12-1999 7.4.3 Weighing test skeins (Method B). Treat the test skeins to remove non-fibrous matter by the appropriate procedure described in4.1 of BS4859:1989, then condition them for24h in an atmos

24、phere as described in clause6. Weigh each skein to an accuracy of0.2%. 7.5 Calculation of results Calculate the linear density in tex units of each test skein using the following expression: where 8 Determination of width Determine the width of a tape yarn by comparing it with a graticule calibrated

25、 in0.05mm divisions, both being examined by means of a viewing lens (seeFigure 1) or by means of a projection microscope, taking one reading per package. Record the width to the nearest0.1mm. 9 Determination of thickness For determination of thickness of a tape yarn use the method described in BS254

26、4,with a foot pressure of between100kPa and200kPa. NOTE 1This method is not suitable for ridged tapes. NOTE 2The pressure of between100kPa and200kPa is that applying over the full area of the presser-foot. 10 Determination of twist 10.1 General This method is based on that given in BS2085and describ

27、es a method for determination of twist (expressed as turns per unit length) of polyolefin tape yarns in single, plied and cabled constructions. NOTEThe designation and direction of twist in single, plied and cabled yarns are given in BS946. 10.2 Apparatus 10.2.1 Apparatus for removing twist, consist

28、ing of a yarn clamp not capable of rotation and a yarn clamp capable of rotation in either direction provided, preferably through gearing, with a revolution counter. The counter shall be capable of recording the number of turns of the rotatable clamp to an accuracy of one-tenth of a turn. The distan

29、ce between the rotatable and non-rotatable clamps shall be set at a minimum of0.25m. Means shall be provided for tensioning the specimen prior to clamping. 10.3 Sampling Select test specimens as described in clause4. Take no specimens from within1m of the end of the package. Owing to the high level

30、of twist liveliness of polyolefin tape yarns, it is recommended that the specimen lengths be tested without cutting from the main body of the yarn in order to avoid loss of twist. Use a sufficiently long test specimen to ensure adequate clamping in the apparatus and discard a few metres of yarn betw

31、een each test specimen length. Withdraw specimens for twist testing from a normal size package in the same manner as that which would normally be used when the yarn passes to the next stage of manufacture or processing. The method may be varied by agreement between the parties concerned, but care is

32、 required because the twist is changed by over-end withdrawal of yarns from a package but is not changed by withdrawal of yarn tangentially from the side of a package. It is essential that the method used to obtain specimens be clearly stated. 10.4 Procedure To ensure reproducible results mount test

33、 specimens in the clamps under a tension of5 1mN/tex. Remove the twist by turning the rotatable clamp. Insert a needle and draw it between the fibres or other structural components to indicate the removal of the twist. Record the test length and the number of turns of the rotatable clamp necessary t

34、o remove the twist from the specimen of yarn under test to one-tenth of a turn. When the twist in a component of a compound structure is measured, first use the twist-testing apparatus to separate the components. Remove these and secure their ends to avoid alteration of their twist. Insert the compo

35、nents separately in the apparatus and determine the twist as above. 10.5 Expression of results Divide the mean value of the individual observations by the test length of the specimen to obtain the number of turns per metre in the yarn. The direction of twist (i.e.“S” or “Z” as defined in BS946) shal

36、l be recorded with any special information concerning the means of withdrawal of the test specimens from the yarn packages. L is the true girth of wrap reel (in m); M is the mass of the test skein (in g); N is the number of turns on the wrap reel. linear density in tex units M 1000 NL - =BS4611:1989

37、 BSI 12-1999 3 10.6 Test report The test report shall include the following information: a) the number and date of this British Standard, i.e.BS4611:1989; b) details of the sample tested; c) the result obtained expressed as in10.5. 11 Determination of breaking strength, extension, tenacity and elast

38、ic modulus 11.1 General Carry out the test as described in BS1932-1except that the length of test specimens shall be250mm and the speed of testing250mm/min. Calculate the breaking strength and extension of the sample. Calculate the tenacity of each test specimen by dividing the breaking strength by

39、the linear density of the yarn as determined in clause7, expressing the results to three significant figures and using the units mN/tex. 11.2 Elastic modulus For yarns having a breaking extension in excess of5%, the preferred elastic modulus is the5% secant modulus. For yarns having a breaking exten

40、sion less than5% but greater than2%, the preferred elastic modulus is the2% secant modulus. The elastic modulus is calculated from the appropriate values of strength and extension obtained by the method given in11.1. NOTEThe pre-tension given in BS1932-1defines the true origin. Measure the modulus b

41、y first extending the smooth part of the force/extension curve near the origin to zero and drawing a secant to the point corresponding to5% or2% extension (see Figure 2) depending upon the breaking extension of the yarn. Express the modulus in mN/texi.e. Express the results to three significant figu

42、res and record the appropriate percentile value of the secant modulus with the results. 12 Determination of colour fastness to light Determine colour fastness to light in accordance with the procedure of BS1006, section B02, method2. 13 Determination of heat shrinkage using an oil bath 13.1 Apparatu

43、s 13.1.1 Oil bath, sufficiently deep for the specimens to be fully immersed and capable of maintaining an agreed temperature between90 C and150 C to an accuracy of 0.50 C. The bath shall be of such a depth that the weight pieces are supported only by the tape,i.e.the weight pieces shall not be allow

44、ed to rest on the bottom of the bath. NOTEIf no temperature is specified it should be assumed that the testing temperature is130 C for polypropylene and100 C for high density polyethylene. 13.1.2 Fluid capable of being heated at 150 C without decomposition and inert to the specimen. A suitable liqui

45、d is silicone oil of 50 10 3Pas viscosity. 13.1.3 Specimen holder, to enable the specimens to be fully immersed. NOTEA piece of heavy gauge wire bent to a suitable shape is convenient. 13.1.4 Lead, in wire or sheet form, for fashioning weights to apply tension to the specimens. 13.2 Test specimens F

46、ive specimens each about300mm long are required. 13.3 Procedure Determine the linear density of the tape yarn according to the method described in clause7. Prepare weight pieces, each having a mass (ingrams) equal to0.05 1% times the linear density value (in tex). Tie one end of each specimen to the

47、 specimen holder and attach one of the prepared weight pieces to the other end. Make two marks on each specimen such that: a) the distance between the marks is at least250mm; b) the distance from the top mark to the specimen holder is at least10mm; c) the distance from the bottom mark to the point o

48、f attachment of the weight piece is at least10mm.BS4611:1989 4 BSI 12-1999 Figure 1 Measurement of width Figure 2 Method for determining elastic modulusBS4611:1989 BSI 12-1999 5 With the specimen holder clamped so that the specimens are hanging vertically under the tension imposed by the attached we

49、ight pieces, measure the distance between the insides of the two marks to an accuracy of 0.5mm. Totally immerse the specimens in the oil for20 1s. On removal from the bath lay the specimens horizontally on absorbent paper and allow to cool for10min. Wipe surplus oil from the specimens, reclamp the specimen holder so that the specimens again hang vertically and measure the distance between the two marks. 13.4 Calculation and expression of results For each specimen calculate the shrinkage from the following formula: where 1