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1、BRITISH STANDARD AEROSPACE SERIES BS 4F 118: 1990 (Superseding BS 3F 118:1980) Specification for 50 g/m2 nylon parachute fabric Licensed Copy: sheffieldun sheffieldun, na, Fri Dec 01 07:36:37 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 4F 118:1990 This British Standard, having been prepared under
2、the direction of the Aerospace Standards Policy Committee, was published under the authority of the Board of BSI and comes into effect on 28 September 1990 BSI 01-2000 The following BSI references relate to the work on this standard: Committee reference ACE/54 Draft for comment 87/76860 DC ISBN 0 58
3、0 18515 X Committees responsible for this British Standard The preparation of this British Standard was entrusted by the Aerospace Standards Policy Committee (ACE/-) to Technical Committee ACE/54, upon which the following bodies were represented: British Fabric Association British Rubber Manufacture
4、rs Association British Textile Employers Association Man-made Fibres Producers Committee Ministry of Defence Society of British Aerospace Companies Ltd. Society of Dyers and Colourists Amendments issued since publication Amd. No.Date of issueComments Licensed Copy: sheffieldun sheffieldun, na, Fri D
5、ec 01 07:36:37 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 4F 118:1990 BSI 01-2000i Contents Page Committees responsibleInside front cover Forewordii 1Scope1 2General requirements1 3Yarn1 4Manufacture1 5Finish1 6Construction and properties of finished fabric2 7Permeability2 8Water extractable matt
6、er2 9Identification2 Appendix A Information to be supplied by the purchaser4 Appendix B Heat strength loss test4 Table 1 General requirements (given in BS F 100)1 Table 2 Construction and properties of finished fabric2 Table 3 Permeability requirements3 Publications referred toInside back cover Lice
7、nsed Copy: sheffieldun sheffieldun, na, Fri Dec 01 07:36:37 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 4F 118:1990 ii BSI 01-2000 Foreword This British Standard, prepared under the direction of the Aerospace Standards Policy Committee, is one of a series for textiles of a quality suitable for aer
8、ospace purposes, and is a revision of BS 3F 118:1980 which is withdrawn. During its preparation account has been taken of the fact that the term “permeability” is now used in place of “porosity”, and metric units for this property are included for the first time. Quality requirements as defined in t
9、he latest edition of BS F 100 are also included, as are details of information to be supplied by the purchaser and a test for heat strength loss. A British Standard does not purport to include all the necessary provisions of a contract. Users of British Standards are responsible for their correct ap
10、plication. 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, pages 1 to 6, an inside back cover and a back cover. This standard has been updated (see copyright d
11、ate) and may have had amendments incorporated. This will be indicated in the amendment table on the inside front cover. Licensed Copy: sheffieldun sheffieldun, na, Fri Dec 01 07:36:37 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 4F 118:1990 BSI 01-20001 1 Scope This British Standard specifies the r
12、equirements for a range of nylon fabrics, of nominal mass per unit area of 50 g/m2 for aerospace purposes, primarily for parachute canopies. NOTE 1The information to be supplied by the purchaser in the contract or order is listed in Appendix A. NOTE 2The titles of the publications referred to in thi
13、s standard are listed on the inside back cover. NOTE 3The latest revision of an Aerospace Series Standard is indicated by a prefix number. 2 General requirements 2.1 In addition to the requirements specified in clauses 2 to 9, the following sections and clauses of the latest edition of BS F 100 shal
14、l apply (see Table 1). 2.2 The breaking strength and extension at break of the yarn (see 3.2) shall be determined in accordance with BS 1932-1 except that the number of tests required to produce a package mean shall be 5. 2.3 The yarn twist shall be determined in accordance with BS 2085 except that
15、the number of tests required to produce a package mean shall be 5. 3 Yarn 3.1 Type The fabric shall be woven from continuous filament, round cross-section, high tenacity nylon 6.6 yarn manufactured from bright heat resistant polymer. 3.2 Properties 3.2.1 The yarn prior to twisting shall have the fol
16、lowing properties: a) a nominal linear density of 50 dtex and contain 15 filaments; b) a mean breaking strength per package of not less than 260 cN, and a mean extension at break per package not exceeding 30 %. 3.2.2 The yarn prior to twisting shall lost not more than 20 % of its original strength,
17、when tested in accordance with the heat strength loss test described in Appendix B. 4 Manufacture 4.1 The weave shall be plain. 4.2 In fabric 1302 a single black thread, the same count as the warp ends, shall be included in the fabric not less than 50 mm in from each finished edge, to distinguish th
18、is fabric from fabrics 556 and 854. 4.3 When fabric woven as 1302 is used to produce fabric 1307, the black identifying thread shall also be present in fabric 1307. 5 Finish 5.1 General 5.1.1 Except for fabric 1307, the fabric shall not be pressed or calendered and shall be supplied scoured and eith
19、er: a) undyed; or b) dyed (see 5.2). Table 1 General requirements (given in BS F 100) SectionTitleRequirements and tests 1GeneralAll requirements 2Quality requirementsRequirements for the manufacture of wide fabrics Requirements for dyed textiles Requirements for dimensions and tolerances: general a
20、nd wide fabrics Requirements for freedom from corrosive impurities Requirements for freedom from defects 3Physical testsTest for the determination of mass of wide fabrics Tests for breaking strength and extension under load of wide fabrics Test for tearing strength Test for air porositya of parachut
21、e fabrics 4Chemical testsTest for water extractable matter a In the context of the method of test specified in BS F 100 the words “porosity” and “permeability” are interchangeable. Licensed Copy: sheffieldun sheffieldun, na, Fri Dec 01 07:36:37 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 4F 118:19
22、90 2 BSI 01-2000 5.1.2 Fabric 1307 shall be supplied scoured, either: a) undyed; or b) dyed (see 5.2). and calendered on both sides. 5.2 Dyeing Where dyeing is required, the colour of the fabric shall be specified either by reference to a British Standard, e.g. BS 381 C, or otherwise by pattern. NOT
23、EThe requirement for dyed or undyed fabric should be specified in the contract or order (see Appendix A). 5.3 Calendering Where calendering is required, the method of calendering shall be at the discretion of the finisher provided that the finished fabric complies with Table 2 and clause 7 and has a
24、 similar appearance on both faces. 6 Construction and properties of finished fabric NOTE 1The minimum usable width of the finished fabric should be as stated by the purchaser in the contract or order (see Appendix A) but a minimum usable width of 920 mm is usually supplied. NOTE 2The fabric may be w
25、oven in multiple widths with leno weave selvedges, and slit to yield finished fabric of the minimum usable width stipulated. When tested in accordance with clause 2, the fabric in the finished state shall comply with the requirements of Table 2. 7 Permeability When tested in accordance with clause 2
26、, each piece of finished fabric shall have an average permeability as shown in Table 3. NOTEIt is most desirable that the average permeability of the fabric shall be as near as possible to the relevant mean figure shown in Table 3, and that the variation between the individual readings should be as
27、low as possible. 8 Water extractable matter When tested in accordance with clause 2, the amount of water extractable matter in the finished fabric shall not exceed 1.0 % by mass. 9 Identification The fabric shall be identified for ordering purposes by the number and date of this British Standard, i.
28、e. BS 4F 118:19901), together with the relevant designation given in Table 2 and, if required dyed, the colour. NOTEThis identification may be codified, e.g. fabric 854 required dyed olive drab may be identified as BS 4F 118/854/BS 381 C No. 298. Table 2 Construction and properties of finished fabri
29、c 1) Marking BS 4F 118:1990 on or in relation to a product represents a manufacturers declaration of conformity, i.e. a claim by or on behalf of the manufacturer that the product meets the requirements of the standard. The accuracy of the claim is therefore solely the responsibility of the person ma
30、king the claim. Such a declaration is not to be confused with third party certification of conformity, which may also be desirable. Designation Nominal yarn twist Minimum numbera of threads per centimetre Maximum mass per unit area Minimum average breaking strength Minimum breaking extension Minimum
31、b tearing strength WarpWeftWarpWeftWarpWeftWarpWeftWarpWeft 556 turns/m 160 or 295 turns/m Spinning39.539.5 g/m2 50 N/50 mm 510 N/50 mm 510 % 22 % 22 N 30 N 25 854 160 295 295 295 160 295 39.5385047547522223030 1302160 or 295 Spinning41.541.55251051022223227 1307160 or 295 Spinning39.539.55251051022
32、223025 a Calculated from the number of threads in a measured length of not less than 2 cm. b Warp tear means tearing across warp threads. Weft tear means tearing across weft threads. Licensed Copy: sheffieldun sheffieldun, na, Fri Dec 01 07:36:37 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 4F 118:
33、1990 BSI 01-20003 Table 3 Permeability requirements FabricAverage permeability 556 854 1302 1307 12.5 2.5a (3 800 750)b 23 2.5a (7 000 750)b 7 1.5a (2 150 450)b 2.5 1.5a ( 750 450)b a Average permeability readings refer to ft3/(ft2s), i.e. volume of air in cubic feet passing through 1 ft2 of fabric
34、in 1 s at 10 in (25.4 cm) water gauge. b Average permeability readings refer to L/(m2s), i.e. volume of air in litres passing through 1 m2 of fabric in 1 s at 25.4 cm (10 in) water gauge. Licensed Copy: sheffieldun sheffieldun, na, Fri Dec 01 07:36:37 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 4F
35、 118:1990 4 BSI 01-2000 Appendix A Information to be supplied by the purchaser The following information should be stated by the purchaser in his contract or order: a) the number of this British Standard, i.e. BS 4F 118; b) the fabric designation from Table 2; c) whether the fabric is required dyed
36、or undyed (see clause 5); d) the minimum usable width required (see clause 6). Appendix B Heat strength loss test B.1 Principle Specimens of yarn are heated in an oven for a specified time and temperature. The specimens are then removed from the oven, conditioned, and the breaking strength is determ
37、ined. The strength lost during treatment is expressed as a percentage of the unheated yarn breaking strength as determined from unheated comparison specimens. B.2 Definition strength loss. The breaking strength lost after a specified heat treatment. NOTEIt is usually expressed as a percentage of the
38、 original strength. B.3 Apparatus B.3.1 Tensile testing machine to BS 1610-1 graded to 1.0 or higher and fitted with the appropriate load cell and clamps. B.3.2 Laboratory oven of suitable size capable of providing temperatures within the range 150 C to 250 C with control of the selected temperature
39、 to 2 C. To ensure uniform temperature distribution the oven should preferably be fitted with a fan. It is important that the oven regains the set temperature within 3 min of shutting the door, without any appreciable overshoot (not greater than 2 C). The oven should be switched on at least 3 h befo
40、re use, or preferably left permanently switched on. B.3.3 Suitable timer B.3.4 Wrap wheel of 1 m circumference B.3.5 Heat resistant gloves B.3.6 Means of suspending the yarn samples in the oven, e.g. a frame or metal rod fitted with bulldog clips. B.3.7 Tie-on labels B.4 Conditioning and testing atm
41、osphere All samples are conditioned and all tests carried out in the standard atmosphere for testing defined in BS F 100, i.e. a relative humidity of 65 2 % and a temperature of 20 2 C. B.5 Test specimens B.5.1 Unwrap and discard the surface layers from each package to be tested. B.5.2 Using the wra
42、p wheel, run off from each package sufficient yarn to carry out five tests. B.5.3 Tie the free ends together to form a skein, release the retractable arm of the wrap wheel, and remove the skein, taking care not to damage the yarn. B.5.4 Double the skein and attach a label noting the specimen referen
43、ce. B.5.5 Repeat B.5.2 to B.5.4 for the unheated samples and place in the conditioning atmosphere while the first samples are heated. B.6 Procedure B.6.1 Set the oven temperature to 180 2 C. B.6.2 For the yarn that is to be heated, suspend each folded skein from a bulldog clip on the rod, or from a
44、hook on the frame. B.6.3 When the oven is controlling at the required temperature, open the oven door, insert the rod or hook frame and close the door. Complete this operation with minimum delay to avoid excessive loss of oven heat. B.6.4 Start the timer. B.6.5 After 60 1 min put on heat resistant g
45、loves, open the oven door and remove the rod or frame. Licensed Copy: sheffieldun sheffieldun, na, Fri Dec 01 07:36:37 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 4F 118:1990 BSI 01-20005 B.6.6 Hang the skeins to condition in the standard atmosphere for testing. Condition for a minimum of 2 h. B.6
46、.7 Determine the breaking strength of the unheated and the heated specimens. Use the following conditions: a) gauge length of 250 1 mm, a crosshead speed of 100 mm/min; b) gauge length of 500 1 mm, a crosshead speed of 200 mm/min. B.6.8 Record the breaking strength in newtons to the nearest 0.1 N. B
47、.7 Calculation and expression of results B.7.1 Calculate the mean breaking strength for the unheated control sample and for the heated sample in newtons. B.7.2 Calculate the percentage strength loss as follows. B.8 Report Report the percentage strength loss of the material tested to the nearest 0.1
48、%. Licensed Copy: sheffieldun sheffieldun, na, Fri Dec 01 07:36:37 GMT+00:00 2006, Uncontrolled Copy, (c) BSI 6 blank Licensed Copy: sheffieldun sheffieldun, na, Fri Dec 01 07:36:37 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 4F 118:1990 BSI 01-2000 Publications referred to BS F 100, Procedure for
49、 inspection and testing of textiles for aerospace purposes. BS 381 C, Specification for colours for identification, coding and special purposes. BS 1610, Materials testing machines and force verification equipment. BS 1610-1, Specification for the grading of the forces applied by materials testing machines. BS 1932, Methods of testing the strength of yarns from packages. BS 1932-1, Determination of breaking strength and extension. BS 2085, Method of test for determination of twist in yarns, direct counting method. Licensed C
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