1、ASTM DI543 b 0757530 002220b 7 W,d-O9-pS Designation:D 1543-86 4Nb AMERICAN SOCIETY FOR TESTING AND MATERIALS 1916 Race St.Philadelphia,Pa.19103 Reprinted from the Annual Book of A S T M Standards,Copflight ASTM If not listed in the.current combined index,will appear in the next edition.Standard Tes
2、t Method for COLOR PERMANENCE OF WHITE ARCHITECTURAL ENAMELS This standard is issued under the fixed designation D 1543;tlie number immediately following the designation indicates the year of original adoption or,in the caseof rehion,the year of last revision.A number in parenthes indicates the year
3、 of last reapproval.A superscript epsilon(e)indicates an editorial change since the last revision or reapproval.1.Scope 1.1 This test method describes a laboratory procedure for evaluatiog the color permanence of white architectural enamels.1.2 Tfis standard may involve hazardoris ma-terials.operati
4、ons,and eqtiipinetit.This standard does not pirrport to address all o f the safity prob-lems associated with its irse.It i s the responsibil-ity o f the user qf this standard to establish appro-priate safry and healii practices and determine the applicabilty o f regdatory littiirations prior to irse
5、.2.Referenced Document 2.1 ASTM Standard:D2224 Method for Calculation of Color Differences from Instrumentally Measured Color Coordinates 3.Summary of Method 3.1 Panels coated with the test enamels are exposed in the dark to an atmosphere of dry sulfur dioxide(SO,)for 24 li.Color measure-ments befor
6、e and after exposure are made to determine the color change.4.Significance and Use 4.1 Interior white enamels change color fre-quently in use.This test method describes a procedure in which enamels are exposed to a synthetic atmosphere that has been found to cause color changes approximately equal t
7、o those caused by home atmospheres.5.Apparatus 5.1 The apparatus for causing accelerated color change shall be assembled as shown in Fig.1 and shall consist of the following components:5.1.1 Glass Bottles,three 8-oz(250-mL)ca-pacity,with a minimum inside diameter of 2 in.(50 mm).5.1.2 Specitnen Rack
8、,corrosion-resistant that fits into the test chamber to hold test panels suspended from corrosion-resistanf hooks spaced on the rack so that the panels do not touch each other or the container.5.I.3 Test Chamber,gas-tight 5-gal(19-L)container,coated to prevent corrosion or made of corrosion-resistin
9、g matenai.Inlet and outlet tubes shall be provided.5.1.4 Tiibing-SuEcient tubing having%-in.(6.4-mm)inside diameter to connect the cylinder of sulfur dioxide,the bottle of sulfurk acid,the empty bottle,and the test chamber.The tubing shall be arranged so that the inlet openings are located near the
10、bottom of each container(Fig.1).6.Reagents 6.1 Sii&a Dioxide(SO2).6.2 Siric Acid(sp gr 1.84)-Concentrated sulfuric acid(H2S04).7.Procedure 7.1 Determine the color of the unexposed panels by measuring them in accordance with a test method mutually agreed upon between the purchaser and the manufacture
11、r.This test method is under the jurisdiction of ASTM Com-mittee D-1 on Paint and Related Coatings and Materials andis thedirectresponsibility o f Subcommittee Do1.27 on Accelerated Testing.Current edition approved April 25,1986.Published June 1986.Originally published as D 1543-58 T.LsLst previous e
12、dip D 1543-63(1981).Annual Book ofAsTh4 Standards.Vol 06.01.NOTICE:This standard has either been superseded and replaced by a new version or discontinued.Contact ASTM International(www.astm.org)for the latest information.NOTE-It is recommended that measurements to determine color change be made in a
13、ccordance with Method D 2244.7.2 Suspend the test panels in the test chamber so as to allow free circulation of the gas.7.3 Assemble the apparatus as shown in Fig.1.Fill one bottle half full with the H2S04.Adjust the inlet tube in the acid bottle so that the diffu-sion disk is 2 in.(50 mm)below the
14、surface of the acid.7.4 Pass SO2 from the cylinder through the sulfuric acid bubble jar,through the empty bottle into the test chamber.Adjust the flow to 100 to 150 bubbles per minute through the water bottle for the first 15 min to sweep out the test chamber,and then reduce it to 50 to 60 bubbles p
15、er minute for the remainder of the test.7.5 Continue the exposure of the test panels for 24 h f 15 min or any other period that is mutually agreeable.7.6 Remove the panels and determine their color in the same manner as before exposure D 1543(7.1).Panels must be measured within 1 h after completion
16、of the exposure.8.Calculation 8.1 Calculate the color difference between the before and after exposure in accordance with the requirements of the selected ASTM test method for color difference or the test method used by mutual agreement(see 7.1).9.Report posed and unexposed panels.10.Precision and Bias 10.1 This test method should predict color changes caused by home atmospheres within&lo%.Tests made by different laboratories should give a reproducibility of+5%.10.2 Bias has not been determined
