1、BRITISH STANDARD BS6909:1988 Method for Generation and counting of the airborne linting propensity of fabrics in the dry state UDC 677488:615.468.47:620.1BS6909:1988 This British Standard, having been prepared under the directionof the Textiles and Clothing Standards Committee, was published under t
2、he authorityof the Board of BSI andcomes into effect on 29January1988 BSI08-1999 The following BSI references relate to the work on this standard: Committee referenceTCM/47 Draft for comment86/36079 DC ISBN 0 580 16276 1 Committees responsible for this British Standard The preparation of this Britis
3、h Standard was entrusted by the Textiles and Clothing Standards Committee (TCM/-) to Technical CommitteeTCM/47, upon which the following bodies were represented: Adhesive Tape Manufacturers Association British Nonwovens Manufacturers Association Guild of Hospital Pharmacists Institute of Sterile Ser
4、vices Management Man-made Fibres Producers Committee Medical Sterile Products Association Sterilisation Packaging Materials Association Surgical Dressings Manufacturers Association Textile Research Council Amendments issued since publication Amd. No. Date of issue CommentsBS6909:1988 BSI 08-1999 i C
5、ontents Page Committees responsible Inside front cover Foreword ii 1 Scope 1 2 Definition 1 3 Principle 1 4 Apparatus 1 5 Atmosphere for conditioning and testing 1 6 Preparation of test specimens 1 7 Procedure 1 8 Calculation and expression of results 2 9 Test report 2 Appendix A Recommended flexing
6、 apparatus 3 Figure 1 Modified G/F tester 4 Figure 2 K/F Flex tester 5 Table 1 Requirements for apparatus 2 Publications referred to Inside back coverBS6909:1988 ii BSI 08-1999 Foreword This British Standard has been prepared under the direction of the Textiles and Clothing Standards Committee. When
7、 purchasing fabrics or garments for use in the micro-electronics industry, hospital operating theatres or similar environments, the manufacturer or user needs to know that linting (particle shedding) will not occur in use, thereby preventing loose particles from settling, for example, on electronic
8、components or in surgical wounds. 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 Standard does not of itself confer immunity from legal obligations. Summary
9、 of pages This document comprises a front cover, an inside front cover, pagesi andii, pages1 to6, an inside back 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 cov
10、er.BS6909:1988 BSI 08-1999 1 1 Scope This British Standard describes a method of testing fabrics for their linting propensity. The test is applicable to all fabrics. NOTE 1Absolute values will not normally be possible, but the method is suitable for comparisons between a wide range of surgical fabri
11、cs and between a wide range of clean room fabrics. The results may be used to assess the initial cleanliness and the lint generating potential of base/composite materials but should not be applied to end products. NOTE 2The titles of the publications referred to in this standard are listed on the in
12、side back cover. 2 Definition For the purposes of this British Standard the following definition applies. linting the action of shedding of airborne particles from a fabric on mechanical flexing 3 Principle The relative level of particles released from a fabric is determined when the fabric is subje
13、cted to a continuous twisting movement, during which air, with a known concentration of particles, at a controlled rate, is passed through a chamber enclosing the specimen. The level of particles above a minimum size carried out of the chamber is counted for successive periods of time. 4 Apparatus 4
14、.1 Flexing apparatus, complying with the requirements of either apparatus G/F or K/F as shown in Table 1 1)and consisting of two discs initially separated. One disc is fixed, whilst the other is able to advance towards the fixed disc with simultaneous rotation through a given angle. NOTEExamples of
15、suitable apparatus are illustrated in Figure 1 and Figure 2. 4.2 Particle counter, capable of sampling airborne particles via an outlet port(s) on the flexing apparatus. NOTEIn the selection of a suitable particle counter, attention is drawn to BS3406-7, which describes features of use of such parti
16、cle counters in order to standardize their operation and ensure consistency of performance. The user should decide which range of particle size(s) is most appropriate for the samples under test. 4.3 Laminar flow hood, for use with apparatus K/F. 4.4 Enclosure, with inlet and outlet ports and a remov
17、able lid for use with apparatus G/F. NOTEThis is used as an alternative to the hood given in4.3. 4.5 Means to produce the conditioning atmosphere specified in clause5. 4.6 Precision paper cutter, with sample holder or a cutting press with appropriate cutting die. 5 Atmosphere for conditioning and te
18、sting The atmosphere required for conditioning and testing shall be the standard temperate atmosphere for testing textiles specified in BS1051. 6 Preparation of test specimens 6.1 After receipt, handle the fabric as little as possible and do not sharply fold, wrinkle or crease it in any other way th
19、an by conditioning. Do not shake the specimens prior to testing, as this will yield incorrect results. 6.2 Cut two specimens in both machine direction and cross direction to a size specified in Table 1, as appropriate, and identify the inner and outer face of each specimen. For each direction one sp
20、ecimen shall be tested on the inner face and one on the outer face. 6.3 Condition the specimens to be tested in the standard atmosphere for testing specified in clause5 for at least24h. 7 Procedure 7.1 Conduct the test in the standard atmosphere for testing specified in clause5. 7.2 Allow an initial
21、 period of10min, or as indicated in the manufacturers operating instructions, for the particle counter(4.2) to warm up. 7.3 Open the chamber of the flexing apparatus(4.1) and attach a specimen to the fully separated disc holders and secure with either hose clips or spring clamps, ensuring that the f
22、abric is mounted such that the machine direction or cross direction is parallel to the axis of the flex tester. If using the G/F type, the circular disc shaped heads shall be turned to their extreme open condition before the specimen is attached. The length of the specimen shall be equal to the maxi
23、mum distance between the discs plus an allowance for clamping, i.e.230 2mm, and the width equal to the circumference of the discs plus a small overlap, i.e.305 2mm. 1) For the availability of a suitable flexing apparatus, contact Enquiry Section, BSI, Linford Wood, Milton Keynes, MK14 6LE, enclosing
24、 a stamped addressed envelope for reply.BS6909:1988 2 BSI 08-1999 Table 1 Requirements for apparatus 7.4 Close the chamber and run background particle counts without starting the flex unit. Continue counts until two consecutive counts agree within 20%. Record the average of the two final counts as b
25、ackground readings. NOTEAs an indication of an acceptable level of background counts to be used as a base line for starting the test, the following example is given: 7.5 Start the flexing action and simultaneously start the particle counter. At the end of the first counting period, record the count
26、and, if necessary, restart the counter. Continue recording the particle count, in the same manner, for ten successive counting periods. NOTEThe count rate is influenced by the tension and alignment of the specimen in the apparatus. If fraying of the specimen occurs, any results should be discounted.
27、 7.6 Test further specimens in accordance with the procedure described in7.3 to7.5. Determine the specimen mounted background count before running each specimen. NOTE 1Control fabrics should also be used. Suitable fabrics are those which have been shown by this method to have either a very low linti
28、ng, e.g.spunbonded material, or a high level of linting, e.g.balloon fabric, or perhaps a fabric which is known to have an acceptable level of linting for the proposed application. NOTE 2The ranking of samples under test can be done in a number of ways, e.g.by using the average first minute period c
29、ounts when most lint is likely to be generated. In this respect the ultimate ranking of samples is not specified. 8 Calculation and expression of results Subtract the respective background counts from the flexed specimen count for each fabric orientation for each counting period. Average each period
30、 count for each of the four specimens tested. Average the ten periods counted. 9 Test report The test report shall include the following information: a) the number and date of this British Standard, i.e.BS6909:1988; b) identification of the samples tested; c) the number of measurements carried out o
31、n the sample; d) the size of the specimen; e) the type of apparatus used, i.e.G/F or K/F; f) the size range of measured particles; g) the average of the ten successive counting periods; h) the highest and lowest average period counts for each of the four test specimens; j) details of control fabrics
32、 used; k) any deviations from this method. Type Chamber size Airflow rate Counting period Angle of twist Length of stroke Cycles per minute Specimen size Nominal initial separation of mounting discs Mounting disc diameter dm 3 dm 3 /h s Degrees mm mm mm mm G/F 7.0 0.7 430 40 60 1 440 5 150 5 45 2 23
33、0 2 305 2 210 90 1 K/F 30 3.0 30 3.0 36 1 150 5 105 5 70 2 150 2 150 2 100 75 1 G/F tester Particle size Range per minute 1.54m 5000to7000 34m 200to450 54m 30to80BS6909:1988 BSI 08-1999 3 Appendix A Recommended flexing apparatus A.1 G/F tester A.1.1 General The G/F tester is modified by extending th
34、e base305mm, lengthening the reciprocating shaft by190mm, and enclosing the specimen discs within a clear plastic chamber having a volume of7.0 0.7dm 3as illustrated in Figure 1(a). This chamber is provided with inlet and outlet ports, and a lid to allow the specimen to be mounted readily. NOTEThe p
35、osition of the inlet and outlet ports should be at the same height as the axis of the cylindrical specimen and half way along its length as illustrated in Figure 1(b). A.2 K/F flexing apparatus A.2.1 General A plastic box305mm 305mm 305mm with doors on the front and back is placed around the flexing
36、 discs and a port provided for the inlet probe of the particle counter as shown in Figure 2(a). NOTEThe position of the port for the inlet probe should be at the same height as the bottom specimen holder. Ideally, this equipment should be in a laminar flow hood(4.3) or clean room. If this is not ava
37、ilable the doors of the box and the ports for the reciprocating shaft and probe should be thoroughly sealed and a port provided with a micro filter for the incoming air.BS6909:1988 4 BSI 08-1999 Figure 1 Modified G/F testerBS 6909:1988 BSI 08-1999 5 Figure 2 K/F Flex tester6 blankBS6909:1988 BSI 08-
38、1999 Publications referred to BS1051, Glossary of terms relating to the conditioning, testing and mass determination of textiles. BS3406, Methods for determination of particle size distribution. BS3406-7, Recommendations for single particle light interaction methods. BS6909:1988 BSI 389 Chiswick Hig
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