1、Designation: C 542 05Standard Specification forLock-Strip Gaskets1This standard is issued under the fixed designation C 542; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision. A number in parentheses indicat
2、es the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.This standard has been approved for use by agencies of the Department of Defense.1. Scope1.1 This specification defines the required properties oflock-strip gaskets where resi
3、stance to sunlight, weathering,flame, oxidation, permanent deformation under load, anddiminution of gripping pressure are prime essentials.NOTE 1The requirement of flame propagation may be waived by thearchitect or professional engineer when doing so does not conflict withlocal codes or ordinances.1
4、.2 This specification applies only to the “locking” com-pression type of gasket, sometimes referred to as the “zipper”type.NOTE 2Structural integrity and weather-tightness of the wall requiresthe sound design and installation of the entire system of which the gasketis only one component.1.3 The valu
5、es stated in SI units are to be regarded as thestandard.1.4 Test Method C 1166, as referenced in this specification,should be used to measure and describe the properties ofmaterials, products, or assemblies in response to heat andflame under controlled laboratory conditions and should not beused to
6、describe or appraise the fire hazard or fire risk ofmaterials, products, or assemblies under actual fire conditions.However, results of this test may be used as elements of a firerisk assessment which takes into account all of the factorswhich are pertinent to an assessment of the fire hazard of apa
7、rticular end use.1.5 The following precautionary caveat pertains only to thetest method portion, Section 7, of this specification: Thisstandard does not purport to address the safety concerns, ifany, associated with its use. It is the responsibility of the userof this standard to establish appropria
8、te safety and healthpractices and determine the applicability of regulatory limita-tions prior to use.1.6 The committee with jurisdiction over this standard is notaware of any comparable standards published by other orga-nizations.2. Referenced Documents2.1 ASTM Standards:2C 1166 Test Method for Fla
9、me Propagation of Dense andCellular Elastomeric Gaskets and AccessoriesD15 Methods of Compound and Sample Preparation forPhysical Testing of Rubber Products3D 395 Test Methods for Rubber PropertyCompressionSetD 412 Test Methods for Vulcanized Rubber and Thermo-plastic Rubbers and Thermoplastic Elast
10、omersTensionD 573 Test Method for RubberDeterioration in an AirOvenD 624 Test Method for Tear Strength of ConventionalVulcanized Rubber and Thermoplastic ElastomersD 746 Test Method for Brittleness Temperature of Plasticsand Elastomers by ImpactD 1149 Test Method for Rubber DeteriorationSurfaceOzone
11、 Cracking in a ChamberD 2240 Test Method for Rubber PropertyDurometerHardness2.2 Other Standard:Rubber Handbook, Specifications for Rubber Products43. Materials and Manufacture3.1 All materials and workmanship shall be in accordancewith good commercial practice.3.2 Gaskets shall be manufactured from
12、 an ozone-resistantcompound and shall not be dependent for ozone resistance onsurface protection which can be removed by abrasion, deter-gents, or other means.3.3 Gaskets shall be free of porosity, surface defects, anddimensional irregularities, particularly in the sealing area.3.4 Unless otherwise
13、specified, the material shall be black.3.5 Lubricants used in installation, shall be as recommendedby the gasket manufacturer.1This specification is under the jurisdiction of ASTM Committee C24 onBuilding Seals and Sealants and is the direct responsibility of Subcommittee C24.73on Compression Seal a
14、nd Lock-Strip Gaskets.Current edition approved May 1, 2005. Published June 2005. Originallyapproved in 1965 as C 542 65 T. Last previous edition approved in 2005 asC 542 94(2005).2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org.
15、 For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.3Discontinued; see 1975 Annual Book of ASTM Standards, Part 37. Replaced byPractice D 3182, Test Methods D 3190, and Test Methods D 3192.4Available from Rubber Manufacturers Associat
16、ion, 444 Madison Ave., NewYork, NY.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.4. Physical Properties4.1 The physical properties of the gasket shall conform tothe requirements specified in Table 1.5. Dimensions and Permissible Va
17、riations5.1 Minimum thickness of material between the lockingstrip cavity and the panel or rail channel shall be 2.5 mm (0.10in.).5.2 All cross-sectioned dimensions shall have an RMAClass 2 tolerance, as specified in Table 2 unless otherwiseagreed by the purchaser and seller.6. Sampling6.1 When proo
18、f of conformance with this specification isrequired, the samples shall be taken from the finished productwhenever possible.6.2 When the thickness or shape of the finished productmakes sampling, as specified in Section 6, impossible, themanufacturer shall, upon request of the purchaser at the time of
19、ordering, furnish a sufficient number of test slabs or blocksprepared in accordance with Methods D15 for the properperformance of the required tests. The slabs or blocks shall beprepared from the compound of the same source production lotused in the gasket.7. Test Methods7.1 Tensile Strength and Elo
20、ngationTest in accordancewith Test Methods D 412. Determine percentage change intensile strength and elongation after oven aging for 70 h at 1006 1C (212 6 2F).7.2 Tear ResistanceTest in accordance with Test MethodD 624 using Die C.7.3 HardnessTest in accordance with Test MethodD 2240, using a Type
21、A durometer. If size or shape of thespecimen precludes testing of the finished surface, makemeasurements on a squarely cut end or on a flat sliced or buffedsurface. Determine change in hardness after oven aging for 70hat1006 1C (212 6 2F).7.4 Compression SetTest in accordance with Test Meth-ods D 39
22、5, Method B. Hold the sample under test for 22 h at100 6 1C (212 6 2F). Buffed specimen, taken from material1.5 mm (116 in.) minimum thickness may be superimposed toa total thickness of 13.0 mm (12 in.).7.5 Brittleness TemperatureTest in accordance with TestMethod D 746.7.6 Ozone ResistanceTest in a
23、ccordance with TestMethod D 1149 (Specimen A). Use an ozone concentration of100 mPa, an exposure time of 40 6 2C (104 6 3.6F), and aspecimen elongation of 20 %.7.7 Heat AgingTest the effects of heat aging in accor-dance with Test Method D 573.7.8 Flame PropagationTest Method C 1166.7.8.1 This test i
24、s designed to differentiate the flame propa-gation characteristics of candidate materials used in lock-stripgaskets. It is a small-scale test which enables the specifier toexercise engineering prudence in the selection of materials. Itshould not be used to predict the performance of the testedmateri
25、al in an actual fire situation. It should not be used topredict fuel contribution, rate of flame spread, smoke genera-tion, or the nature of the products of combustion. Testconditions are those most conducive to flame propagation andthe method simulates the worst possible exposure condition.The spec
26、imen is mounted vertically. The igniting flame is hot;the fuel supply is unlimited; and the flame is not removed fromthe specimen throughout the test.TABLE 1 Physical Requirements and Test Methods for GasketsProperty Requirements Test MethodTensile strength, minA14 MPa (2000 psi) D 412Elongation at
27、rupture, min, % 175 D 412Tear resistance, min 214 N/linear cm (120 lbf/linear in.) D 624 (Die C)Hardness, durometer AA75 6 5 D 2240Compression set, max, %, 22 h at 100C (212F) 35 D 395 (Method B)Brittleness temperature, min 40C (40F) D 746Ozone resistance, 100 mPa ozone . .100 h at 40C (104F), 20 %
28、elongation no cracks 73 magnification D 1149 (Specimen A)Heat aging, 70 h at 100C (212F) D 573Change in hardness, maxLoss in tensile strength, max, %Loss in elongation, max, %0 to + 10 Durometer points1540Flame propagationB100 mm (4 in.), max. C 1166Lip pressureCExtruded section, minCorners, min7 N/
29、linear cm (4 lbf/linear in.)7 N/linear cm (4 lbf/linear in.)as specified (see 7.9)AIf a separate stock is used for the locking strip, it may have a hardness of 80 6 5 durometer points, and a minimum tensile strength of 12.5 MPa (1800 psi). In all otherrespects, it must meet these specifications.BThi
30、s requirement may be waived (see Note 1).CIn the case of molded corners with integral sealing devices, the requirement for corner lip pressure may be lowered by the architect or professional engineer.TABLE 2 Cross-Sectional Tolerances Lock-Strip GasketsRMA Class 2, Schedule I, CommercialADimension,m
31、m (in.)Tolerance,plus or minusOver 0 to 2.54 (0 to 0.10) incl. 0.32 (0.013)Over 2.54 to 4.06 (0.10 to 0.16) incl. 0.40 (0.016)Over 4.06 to 6.35 (0.16 to 0.25) incl. 0.50 (0.020)Over 6.35 to 10.16 (0.25 to 0.40) incl. 0.63 (0.025)Over 10.16 to 16.0 (0.40 to 0.63) incl. 0.80 (0.032)Over 16.0 to 25.4 (
32、0.63 to 1.00) incl. 1.00 (0.040)Over 25.4 to40.64 (1.00 to 1.60) incl. 1.25 (0.050)Over 40.64 to 63.5 (1.60 to 2.50) incl. 1.60 (0.063)ARubber Handbook, Specifications for Rubber Products, Table 12.C5420527.9 Lip Pressure:57.9.1 This test method determines the pressure exerted bythe gasket on collat
33、eral material positioned within the gasketchannel or channels. It simulates actual use conditions andprovides a measurement of the force required to open the lipsof the gasket channel to that distance representing the thicknessof material for which the gasket is designed. In the case ofdouble channe
34、l gaskets, this measurement is made with a solidmaterial of the intended thickness in position in the channelopposite to that being tested. Thus these measurements reflectthe forces to be encountered during application.7.9.2 Apparatus:7.9.2.1 The testing machine shall be a power-driventension-testin
35、g machine of the movable cross-head type,equipped with adjustable cross-head speed and a suitabledynamometer and indicating or recording device for measuringthe applied force within 62%.7.9.2.2 The grips to be used with the testing machinedescribed in 7.9.2.1 shall be of a type similar to those show
36、n inFig. 1. They shall exert a uniform pressure across the grippingsurface, increasing as the tension increases, so as to preventuneven slipping.7.9.2.3 The lip dividers used to separate the lips of the testspecimen shall be made of stainless steel as shown in Fig. 2.Their length shall be at least e
37、qual to that of the test specimen.7.9.2.4 The metal spacer to be used when testing double-channel gaskets, as shown in Fig. 1, shall be the same length asthe test specimen, the same thickness as the material the gasketis designed to hold, and at least 13 mm (12 in.) wider than thedepth of the channe
38、l.7.9.3 Test Specimen:7.9.3.1 The extruded test specimen shall be a piece of theactual gasket at least 25 mm (1 in.) in length. A minimum offour specimens from each lot shall be tested.7.9.4 Procedure:7.9.4.1 Place the test specimen in the testing machine asshown in Fig. 1, ensuring that the locking
39、 strip is in place andthat, if it is a double-channel-type gasket, the specified spaceris properly positioned in the channel opposite from that beingtested. Provide means of supporting the test assembly so thatwhen tension is applied to the channel lips, the assembly willremain in a horizontal posit
40、ion (Note 3). It is important toensure that the lip dividers have a secure hold on the gasket lipsand that they are also securely held by the grips of the machine.Conduct the test at 23 6 1C (73.4 6 1.8F).NOTE 3When testing single channel gaskets, the spacers obviouslycannot be used. However, some m
41、eans must be provided to hold the testspecimen in a horizontal position during testing.7.9.4.2 Separate the lips of the gasket channel at a uniformrate of 5.1 mm (0.20 in.)/min, until the distance between thelips is equal to the minimum thickness of the material they aredesigned to hold.7.9.4.3 When
42、 the lips have been separated the specifieddistance, stop the testing machine and record the amount offorce in lbf (or kgf) required to produce this opening.7.9.4.4 Repeat 7.9.4.1-7.9.4.3 until all of the extruded chan-nels of a minimum of four specimens of each type have beentested.7.9.4.5 Calculat
43、e the lip pressure of each channel tested asfollows:Lip pressure, N/linear cm lbf/linear in.!5F/L (1)where:F = force required to open the lips the specified distance, N(lbf), andL = length of test specimen in cm (in.), to the nearest 0.2cm (0.1 in.).7.9.5 ReportThe following test information shall b
44、ereported:7.9.5.1 Date of test,7.9.5.2 Type of testing machine used,7.9.5.3 Description or numbers of the lot or lots tested,7.9.5.4 The width of the filler strip to the nearest 0.025 mm(0.001 in.), and5Supporting data are available from ASTM Headquarters. Request RR: C24-1009.FIG. 1 Tension Tester
45、for Lip PressureC5420537.9.5.5 Lip pressure for each gasket channel tested. 8. Keywords8.1 compression; elastomer; elastomeric; gasket; locking;lock-strip; preformed; seal; strip; zipperFIG. 2 Lip DividersC542054ASTM International takes no position respecting the validity of any patent rights assert
46、ed in connection with any item mentionedin this standard. Users of this standard are expressly advised that determination of the validity of any such patent rights, and the riskof infringement of such rights, are entirely their own responsibility.This standard is subject to revision at any time by t
47、he responsible technical committee and must be reviewed every five years andif not revised, either reapproved or withdrawn. Your comments are invited either for revision of this standard or for additional standardsand should be addressed to ASTM International Headquarters. Your comments will receive
48、 careful consideration at a meeting of theresponsible technical committee, which you may attend. If you feel that your comments have not received a fair hearing you shouldmake your views known to the ASTM Committee on Standards, at the address shown below.This standard is copyrighted by ASTM Interna
49、tional, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959,United States. Individual reprints (single or multiple copies) of this standard may be obtained by contacting ASTM at the aboveaddress or at 610-832-9585 (phone), 610-832-9555 (fax), or serviceastm.org (e-mail); or through the ASTM website(www.astm.org).C542055
