1、BRITISH STANDARD CONFIRMED JULY1986 BS2610:1978 Incorporating Amendment No.1 Method of test for The determination of the cuprammonium fluidity of cotton and certain cellulosic man-made fibres UDC677.21+677.46:532.132:546.56239145BS2610:1978 This British Standard, having been prepared under the direc
2、tionof the Fibres, Yarns andFabrics Standards Committee, was published underthe authority of the Executive Board on 29December1978 BSI08-1999 First published May1955 First revision December1978 The following BSI references relate to the work on this standard: Committee reference TCM/26 Draft for com
3、ment77/35669DC ISBN 0 580 10393 5 Cooperating organizations The Fibres, Yarns and Fabrics Standards Committee, under whose direction this British Standard was prepared, consists of representatives from the following Government departments and scientific and industrial organizations: Association of J
4、ute Spinners and Manufacturers British Man-made Fibres Federation* British Nonwovens Manufacturers Association British Railways Board British Textile Employers Association* Central Council of the Irish Linen Industry Consumer Standards Advisory Committee of BSI Department of Industry, Chemicals and
5、Textiles International Wool Secretariat* Knitting Industries Federation Ltd.* Manchester Chamber of Commerce and Industry Ministry of Defence* Narrow Fabrics Federation Retail Trading Standards Association Textile Institute* Warp Knitters Association Ltd. The organizations marked with an asterisk in
6、 the above list, together with thefollowing, were directly represented on the committee entrusted with the preparation of this British Standard: British Carpet Manufacturers Association British Polyolefin Textiles Association British Textile Confederation Department of Industry, Laboratory of the Go
7、vernment Chemist Manchester Chamber of Commerce Soap and Detergent Industry Association Society of Dyers and Colourists Textile Research Council Wool Textile Delegation Amendments issued since publication Amd. No. Date of issue Comments 4965 November 1985 Indicated by a sideline in the marginBS2610:
8、1978 BSI 08-1999 i Contents Page Cooperating organizations Inside front cover Foreword ii 1 Scope 1 2 References 1 3 Principle 1 4 Definitions 1 5 Reagent 1 6 Apparatus 1 7 Calibration of the viscometer 2 8 Preparation of test specimens 3 9 Test procedure 4 10 Calculation and expression of results 4
9、 11 Report 4 Appendix A Preparation of the solvent 5 Appendix B Determination of copper 5 Appendix C Determination of ammonia 5 Appendix D Determination of nitrite 5 Appendix E Measurement of the volume (V) between top and bottom timing marks 5 Appendix F Measurement of the total volume (V o ) enclo
10、sed by the viscometer 5 Appendix G Weighing and introduction of specimens 6 Appendix H Calculation of the required mass of acetate or triacetate 6 Appendix J Pre-treatment of fibres which are difficult to dissolve 6 Appendix K Position and use of the middle timing mark 7 Figure 1 (1,2,3 and4). Visco
11、meter and ancillary apparatus 8 Figure 2 Blackened glass container for solvent 9 Figure 3 Observation tank with apparatus 9 Table 1 Concentration in solvent of cotton mixtures 3 Table 2 Ratios of cuprammonium fluidity to t 1 /t 2 7 Publications referred to Inside back coverBS2610:1978 ii BSI 08-1999
12、 Foreword This revision has been prepared under the direction of the Fibres, Yarns and Fabrics Standards Committee to take account of changes in techniques and apparatus, and to provide a procedure for mixtures of cellulosic fibres. It is well known that purified natural cellulose dissolves in cupra
13、mmonium hydroxide solution (referred to below as “cuprammonium”) to give a solution that is viscous even at low concentrations. Cellulose that has been partly hydrolyzed or oxidized dissolves to give less viscous (more fluid), solutions at the same concentration. Hydrolytic and oxidative treatments
14、weaken fibres and yarns of cotton, viscose, cupro, modal, deacetylated acetate, acetate or triacetate, and it has been shown that, following a series of such treatments, there is a close, though non-linear, relation between the fall in tensile strength and the fall in viscosity of a solution of give
15、n concentration. If, instead of the viscosity of a solution, its reciprocal, termed for the purposes of this standard “cuprammonium fluidity”, is compared with the loss in strength, it is found that, for many chemical treatments that weaken cellulose, the cuprammonium fluidity increases linearly wit
16、h the percentage fall in strength, over a wide range. For practical purposes, therefore, the cuprammonium fluidity enables a distinction to be made between mechanical and chemical damage, and affords a very convenient measure of the extent of chemical attack that the cellulose has undergone. However
17、, in the special case of damage caused by microorganism enzymes, there is unlikely to be a significant increase in the cuprammonium fluidity. Cotton fibres even after they have been scoured consist of almost undegraded cellulose, and normal bleaching treatments degrade the cellulose only to a modera
18、te extent. On the other hand, the treatments to which cellulose is subjected during the manufacture of viscose, cupro, modal, deacetylated acetate, acetate or triacetate, are much more severe, and the cuprammonium fluidities of their solutions are very much higher than those of cotton if all are mea
19、sured in solutions of the same concentration. The differences are so large that it is impracticable to employ the same viscometer to measure the cuprammonium fluidities of cotton, viscose, cupro, modal, deacetylated acetate, acetate or triacetate, at the same concentration. In practice, it is a grea
20、t convenience to use identical viscometers for all measurements, and this can be done if different standard concentrations are employed for cotton on the one hand and for viscose, cupro, modal, deacetylated acetate, acetate or triacetate on the other. With viscometers of the design employed in this
21、standard suitable concentrations are0.5% for cotton and2.0% for viscose, cupro, modal, deacetylated acetate, acetate or triacetate. When mixtures of cellulosic fibres are to be tested, somewhat different considerations apply, depending on the nature of the blend and on the source of the non-cotton c
22、omponent. In this case, it would be more appropriate to estimate the fluidity of the cotton component only, and for this reason, only methods for determination of the fluidity of the cotton component are given. Since the majority of mixtures are prepared before any treatment is applied which is like
23、ly to affect the fluidity, it can be assumed that any increase in the fluidity value for the cotton component reflects an increase in the fluidity value for the other component, although it should be noted that these changes may not be proportional.BS2610:1978 BSI 08-1999 iii Because of these consid
24、erations three basic methods for calculating test specimen size and test result are given, the first dealing with pure fibre, the second and the third dealing with mixtures of cotton with cellulosic man-made fibres. NOTECuprammonium fluidity is the reciprocal of the dynamic viscosity of a solution o
25、f cellulose of prescribed concentration in a cuprammonium solvent of prescribed composition measured under precisely defined conditions. These solutions commonly exhibit non-Newtonian flow behaviour. Cuprammonium fluidity does not, therefore, have absolute physical significance as does the fluidity
26、of a Newtonian liquid, although it has been expressed in reciprocal poises. It is considered that it should be regarded as an empirical quantity and because of this, the results are given in “units of cuprammonium fluidity”. A British Standard does not purport to include all the necessary provisions
27、 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. Summary of pages This document comprises a front cover, an inside front cover, pagesi toiv, pages1to10, an inside ba
28、ck cover and a back 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.iv blankBS2610:1978 BSI 08-1999 1 1 Scope This British Standard specifies a method for the determination of
29、 the cuprammonium fluidity of cotton, viscose, cupro, modal, deacetylated acetate, acetate or triacetate, and blends of cotton with cellulosic man-made fibres, in cuprammonium hydroxide solution. 2 References The titles of the publications referred to in this standard are listed on the inside back c
30、over. 3 Principle A weighed specimen of the material is dissolved in cuprammonium solvent of specified composition in a defined capillary viscometer. The viscometer and its contents are brought to a temperature of20 C and then the solution is allowed to flow through the capillary of the viscometer,
31、and the time is determined for the meniscus to fall from one fixed mark to the next. The cuprammonium fluidity is calculated by means of a formula containing two constants determined by calibrating the viscometer with a liquid of known kinematic viscosity. 4 Definitions For the purposes of this Brit
32、ish Standard the following definitions apply. 4.1 kinematic fluidity (of a solution) the reciprocal of the kinematic viscosity of the solution 4.2 cuprammonium fluidity (of a specimen ofcotton) the kinematic fluidity (expressed in units of cuprammonium fluidity) of a solution in the specified cupram
33、monium solvent containing0.5g of cellulose per100ml of solution, divided by the density of the solvent. A value of0.94g/cm 3for the density is sufficiently accurate. The cuprammonium fluidity of a specimen of cupro, viscose, modal or deacetylated acetate is similarly defined, except that a solution
34、containing2.0g of cellulose per100ml of solution is used. The cuprammonium fluidity of a specimen of cellulose acetate or triacetate is the cuprammonium fluidity of a solution containing acetate or triacetate equivalent to2.0g of regenerated cellulose per100ml of solution at20 C (see Appendix H) 5 R
35、eagent The following reagent is required. 5.1 Cuprammonium hydroxide solvent containing15 0.1g of copper,200 5g of ammonia, and less than0.5g nitrous acid per litre (referred to as cuprammonium solvent) 1) . The solution shall be free from any deposit. Guidance on the preparation of the solvent and
36、its analysis is given in Appendix A, Appendix B, Appendix C and Appendix D. 6 Apparatus 6.1 Viscometer and fittings. The viscometer shall be of the form illustrated in Figure 1. It consists of a glass tube A sealed to a capillary tube E, both being made of precision-bore tubing with the dimensions s
37、et out below. The instrument is fitted at its upper end with a plastics stopper incorporating a narrow plastics tube provided with a small plastics plug, and at its lower end with rubber tubing and screw clip. The body of the viscometer is provided with three timing rings B, C, D, etched around its
38、circumference. The dimensions of the viscometer 2)and the tolerances shall be as follows: 1) “Shirley cuprammonium” is suitable and available from BDH Ltd, Poole, Dorset. 2) The Shirley “X”-type viscometer, available from Shirley Developments Limited,856 Wilmslow Road, Didsbury, Manchester M208RX, i
39、s suitable. Internal diameter of capillaryE 0.88 0.01mm External diameter of capillaryE 6 2mm Length of capillary E 25 0.5mm Internal diameter of wide tube A 10 0.01mm Wall thickness of tube A 1 mm to 1.5 mm Height of ring B above flat end of capillary E 242 0.5mm Height of ring C above flat end of
40、capillary E 122 0.5mm Height of ring D above flat end of capillary E 62 0.5mm Length of instrument without closing devices 3002mm Length of funnel-shaped seal between wide tube and capillary approximately 10mmBS2610:1978 2 BSI 08-1999 6.2 Glass jackets for the support of the viscometers in the therm
41、ostat during the time required to bring the temperature to20 C and while the time of outflow is being measured. Suitable designs are given in Figure 1(2) for the first operation and Figure 1(3) for the second, but other designs may be equally convenient, provided that the viscometer is held vertical
42、ly while the solution flows out. 6.3 Brass supports for the jackets, with plumb-line or other means of verifying that the jacket is vertical while the time of the flow is being measured. One suitable design is illustrated in Figure 1(4). 6.4 Steel rod 1.6mm diameter, approximately300mm long. 6.5 Bla
43、ckened glass container (see Figure 2) for cuprammonium solvent with an unblackened strip approximately5mm wide down the container. 6.6 Short graduated burette. It is convenient, but not essential, to have the burette graduated in intervals of0.7ml. 6.7 Rotational device, for rotating the filled visc
44、ometers end-over-end at a speed of not more than4 r/min. 6.8 Glass thermostat, with stirrer, capable of being maintained at20 0.2 C. A glass accumulator jar approximately250mm 220mm 350mm has proved suitable. The vessel is conveniently illuminated from behind by means of a cylindrical electric light
45、 bulb and reflector. 6.9 Split-finger second timer or stop-watch graduated in seconds and fifths of a second. 7 Calibration of the viscometer 7.1 The calibration of the viscometer shall include the measurement of the following. a) The time of flow at20 0.2 C of a liquid of known kinematic fluidity f
46、lowing sufficiently slowly to avoid the need for a kinetic energy correction; from this the viscometer constant C is calculated. b) The volume (V) in millilitres between the top and bottom timing marks B and D, measured in accordance with Appendix E from which is calculated a correction constant K,
47、used in applying a kinetic energy correction to observations made on relatively fluid solutions. c) The total volume (V o ) in millilitres enclosed by the viscometer measured in accordance with Appendix F, and used in calculating the mass of cellulose necessary to obtain a solution of the desired co
48、ncentration. 7.2 The following are suitable calibrating liquids. a) An aqueous solution containing approximately65% by mass of commercially pure glycerol. The kinematic fluidity of this solution is determined in a BS/U/C viscometer 3)(see BS188) and is approximately8s/cm 2at20 0.2 C. b) Commercially
49、 pure phenylethanol, further purified by distillation. The kinematic fluidity of this substance is7.14s/cm 2at20 0.2 C. 7.3 Calculation of constants. If the calibrating liquid is a glycerol solution of kinematic fluidity approximately8s/cm 2 , the kinetic energy correction constant K is given by the formula K =0.131Vt gIf the calibrating liquid is phenylethanol, then K =0.117Vt p where t pis the time of flow (in s) of phenylethanol. The viscometer constant C is then calculated by inserting the values of the time of flow t (in s) and the
