1、D8U DRAFT FOR PUBLIC COMMENT Latest date for receipt of comments hument 90/76838 British Standards Institution Ourref ACE/25 Technical Committee ACE/25 Rubber and elastomeric materials for aerospace DRAFT EUROPEAN STANDARD - AEROSPACE SERIES SEALANTS. TEST METHOD. DETERMINATION OF TACK FREE TIME. Th
2、is draft is now available for public comment and your views and technical comments on it would be appreciated. If you have no specific comments to make but find it generally acceptable it would be helpful if you would notify us accordingly. Suggestions entailing revision of the text should indicate
3、the preferred wording. Please quote the relevant clause number against any comment. The Co-ordination of the requirements of this draft with those of any related standards is of particular importance and you are invited to point out any areas where this may be necessary. All comments should be sent
4、to the Cornittee Secretary Mr N R Ledsham at the London- address below. The comments received will be passed to the committee concerned for their consideration; no acknowledgement will normally be sent. Requests for further copies of this draft should be sent to: Sales Administration (Drafts), BSI,
5、Linford Wood, Milton Keynes MK14 6LE. THIS IS A DRAFT AND MUST NOT BE REGARDED OR USED AS A BRITISH STANDARD Head Office Mancheder Office 2 Park Street London WIA 2BS Telephone 01-629 9000 Telex 266933 BSILON G Head Office 3 York Street Manchester M2 2A“ Telephone 061-832 3731 Telex 665969 BSIMAN G
6、825777 BSIMK G Sales 3096 DCL : Key words : Aerospace series Sealants Test method Detennfntion of -. tack-free time Srie arocpotiale Luft-und Raunfshrt Prodaits dtanchit Dichtmassen %idth 25 m, length minicum 150 mi, 5.3 The frame shall be treated with a releese egent. Optionel : frame of aluminiuE,
7、 70 rixa n 150 pm, thickness (3,O 2 0,4) pi. 0656SPOiSCT8 7 Cxditioning The base compound and hrrdener shall be stabilized st (23 2 2) “C in closed contsiaers for st leest 8 hours before testing. 8 Procedure A clean test panel (see clause 6.1) shall be covered with freshly mixed sealing compound to
8、a thickness of (3,O 2 0,4) XE. The right thickness is eesier obteined by means of o frame (see lote : clause 6.3). The test panel shall be kept at (i3 + - 2) OC and (50 + - 5) % rrletive hunidity throughout the test. At the end c.f the specified tack-free time, two polyethylene strips (see clause 6.
9、2) shall be applied to the whole length of the sealing compcwnd and held in place with contact pressure for 2 minutes. The strips shall then be slowly and evenly peeled off by hsnd Et right analis to the sealent surface. The sealant is considered tack-free if: the polyethylene strips come auzy clean
10、 end free of sealant. 9 Expression of results if no serlaat adheres to the polyethylene strips the result shzll be given es passing, othemise not psssing the test. 10 Test report The test report shal1,include the following informztion : e) identification of the s2ple, b) reference to this standard, c) test results, d date of testing. 065ESPOl?TE
