1、Designation: D 4708 07Standard Practice forPreparation of Uniform Free Films of Organic Coatings1This standard is issued under the fixed designation D 4708; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision.
2、 A number in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.1. Scope*1.1 This practice covers the preparation of free films oforganic coatings for use in determining the physical propertiesof the coating
3、s. Procedures are given for preparing free filmson three alternative substrates. These substrates are treated FEP(fluorinated ethylene-propylene) sheet, silicone coated paper,and halosilane coated glass plates.1.2 The values stated in SI units are to be regarded as thestandard. The values given in p
4、arentheses are for informationonly.1.3 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limit
5、ations prior to use.2. Referenced Documents2.1 ASTM Standards:2D 823 Practices for Producing Films of Uniform Thicknessof Paint, Varnish, and Related Products on Test PanelsD 1005 Test Method for Measurement of Dry-Film Thick-ness of Organic Coatings Using MicrometersD 1653 Test Methods for Water Va
6、por Transmission ofOrganic Coating FilmsD 2370 Test Method for Tensile Properties of OrganicCoatings3. Summary of Test Method3.1 Free films are prepared by depositing a uniform wetcoating of the test material on a release substrate. The appliedfilms are dried or baked, cut into appropriate size for
7、theintended physical property test, and then stripped from therelease substrate.4. Significance and Use4.1 Free films are required for conducting tests to evaluatephysical properties such as tensile and elongation (Test MethodD 2370), moisture vapor permeability (Test Methods D 1653),and other physi
8、cal properties of organic coatings where thesubstrate may interfere with the determination.5. Apparatus and Materials5.1 Equipment, for applying films of uniform thickness asdescribed in Practices D 823.5.2 Micrometer Film Thickness Gage, as described in TestMethod D 1005.5.3 Alternative Release Sub
9、strates:5.3.1 Sheet of FEP(polyhexafluoropropylene), preferably50-m (2-mils) thick, coated with a thin film of a drylubricant.3,45.3.2 Sheet of Silicone Coated Paper, preferably 125-m(5-mil) thick.5,45.3.3 Glass Plates, coated with halosilane compound.NOTE 1Other substrates that may be suitable are
10、250-m (10-mil)thick polyethylene, photographic paper, polished steel, and fluoropolymercoated metal panels.5.4 Precision Specimen Cutter, having a double blade witha foot to hold the sample.6,46. Procedure6.1 Prepare the free films by one of the following proce-dures:NOTE 2To prepare specimens for t
11、ensile property tests a precisionspecimen cutter must be used to ensure nick-free edges on the specimens.1This practice is under the jurisdiction of ASTM Committee D01 on Paint andRelated Coatings, Materials, and Applications and is the direct responsibility ofSubcommittee D01.23 on Physical Propert
12、ies of Applied Paint Films.Current edition approved Nov. 1, 2007. Published December 2007. Originallyapproved in 1987. Last previous edition approved in 2004 as D 4708 04.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Ann
13、ual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.3The sole source of supply of dry lubricant (MS-122 Fluorocarbon ReleaseAgent) known to the committee at this time is Miller-Stephenson Chemical Co.,Inc., 55 Backus Ave., Danbury, CT 06810.4
14、If you are aware of alternative suppliers, please provide this information toASTM International Headquarters. Your comments will receive careful consider-ation at a meeting of the responsible technical committee,1which you may attend.5The sole source of supply of silicone coated release paper, Form
15、RP-1K, size858 by 1114 in., known to the committee at this time is the Leneta Co., 15 WhitneyRd., Mahwah, NJ 07430.6The sole source of supply of the JDC Precision Sample Cutter known to thecommittee at this time is the Thwing-Albert Instrument Co., 14 West Collins Ave.,West Berlin, NJ 08091.1*A Summ
16、ary of Changes section appears at the end of this standard.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.Even with this instrument, it is necessary to cut each specimen indepen-dently, allowing at least 13 mm (12 in.) of waste betwe
17、en specimens.6.1.1 FEP Substrate:6.1.1.1 Apply each material to be tested to a sheet of FEPthat has been treated as follows: First, cover a smooth, flatpolished glass plate with a sheet of FEP. Coat the sheetuniformly with a light coat of a dry fluorocarbon lubricant andallow to dry for 24 h at stan
18、dard conditions. Then apply auniform wet coating of the test material on the sheet by one ofthe procedures given in Practices D 823.6.1.1.2 Dry the applied films in 23 6 2C (73.5 6 3.5F)and 50 6 5 % humidity, or bake under conditions mutuallyagreeable to the producer and the user. Dry film thickness
19、esmust not vary by more than the specified or agreed upontolerances of the average film thickness and must be free ofvisible flaws. Most films with a thickness of less than 50 m(2.0 mil) are very difficult to handle.6.1.1.3 When required for further treatment such as weath-ering, remount the coated
20、sheet on a convenient smooth, flatsubstrate such as a glass or steel panel.6.1.1.4 Age or expose the coated sheet to conditions mutu-ally agreed upon. At the end of the aging or exposure period,remove the sheet-backed film from the glass or metal substrateand cut the specimens to size using a sharp
21、knife or theprecision cutter (Note 2). Carefully strip the coating film fromthe sheet substrate.6.1.2 Silicone Coated Paper:6.1.2.1 Apply each material to a sheet of silicone coatedpaper. First, cover a smooth, flat substrate with a sheet of asilicone-coated release paper. Then apply a film of the m
22、aterialunder test, dry or cure, expose or treat if required, and preparetest specimens as described in 6.1.1.6.1.3 Halosilane Coated Glass PlatesApply each mate-rial to a glass plate coated with a halosilane compound. First,coat a glass plate with a thin film of a halosilane compound anddry. Then ap
23、ply a film of the material under test, dry or cure,expose or treat if required, and prepare test specimens asdescribed in 6.1.1.7. Keywords7.1 film; halosilane coated glass plates; lacquer; organiccoatings; paints and related coatings; polyhexafluoropylene(FEP) substrate; silicone-coated paper; subs
24、trates; surfacepreparation; tension (tensile) properties/tests; vapors; varnishesSUMMARY OF CHANGESCommittee D01 has identified the location of selected changes to this standard since the last issue(D 4708 - 99 (2004) that may impact the use of this standard. (Approved November 1, 2007.)(1) Deleted
25、reference to the procedure involving the use ofmercury and tin plate since this involves the use of a hazardousmaterial.ASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this standard. Users of this standard are express
26、ly 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 the responsible technical committee and must be reviewed every five years andif not revised,
27、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 careful consideration at a meeting of theresponsible technical committee, which you may att
28、end. 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 International, 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).D4708072
