1、Designation:C28510(Reapproved 2015)1Standard Test Methods forSieve Analysis of Wet-Milled and Dry-Milled PorcelainEnamel1This standard is issued under the fixed designation C285;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revision,the yea
2、r of last revision.A number in parentheses indicates the year of last reapproval.Asuperscript epsilon()indicates an editorial change since the last revision or reapproval.1NOTESections 4 and 10 corrected editorially in May 2015.INTRODUCTIONThese test methods provide a rapid means of determining the
3、fineness of glass frit in wet-ordry-milled porcelain enamel coating materials by sieve analysis.Fineness is a key predicator offusibility,tearing,gloss,opacity,suspension in the slip,and ease of spraying because of the directrelationship to surface area.1.Scope1.1 These test methods cover the determ
4、ination of thefineness of frit in wet-or dry-milled porcelain enamels andother ceramic coatings for metals by means of the No.200(75-m)or No.325(45-m)sieve.1.2 The two methods appear as follows:SectionsMethod AReferee MethodMethod BRoutine Method4 to 910 to 141.3 Method A is intended for use where a
5、 referee method ofhigher accuracy is required,while Method B is intended tomeet the needs of normal enamel plant production controloperations where a rapid,simplified method of sieve testing isrequired.The accuracy of the simplified method has proved tobe entirely adequate for this use.The simplifie
6、d test,however,is not recommended where high accuracy is required.1.4 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 applic
7、a-bility of regulatory limitations prior to use.2.Referenced Documents2.1 ASTM Standards:2E11 Specification for Woven Wire Test Sieve Cloth and TestSieves3.Significance and Use3.1 The fineness of the frit has a direct bearing on many ofits properties,such as fusibility,tearing,gloss,opacity,suspen-s
8、ion in the slip,and ease of spraying.METHOD AREFEREE METHOD4.Apparatus4.1 BalanceThe balance or scale shall be of at least 500-gcapacity,and accurate to 0.1 g.4.2 SievesThe sieves shall conform to Specification E11.They shall include the No.40(425-m)sieve and also the No.200(75-m)or the No.325(45-m)
9、sieve,or both.A No.325sieve shall be used when the fineness is such that,from asample containing 100 g of dry solids,less than 2 g is retainedon a No.200 sieve.An 8-in.(203-mm)full-height sieve isrecommended.This height is preferred because there is lesstendency to flood or splash,and also because i
10、t fits commercialautomatic tapping and shaking machines.All sieves used for1These test methods are under the jurisdiction of ASTM Committee B08 onMetallic and Inorganic Coatings and are the direct responsibility of SubcommitteeB08.12 on Materials for Porcelain Enamel and Ceramic-Metal Systems.Curren
11、t edition approved May 1,2015.Published May 2015.Originallyapproved in 1951.Last previous edition approved in 2010 as C285 10.DOI:10.1520/C0285-10R15.2For referenced ASTM standards,visit the ASTM website,www.astm.org,orcontact ASTM Customer Service at serviceastm.org.For Annual Book of ASTMStandards
12、 volume information,refer to the standards Document Summary page onthe ASTM website.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 testing shall be standardized initially and after every 50 testsagainst a reference sieve tested by the Na
13、tional Bureau ofStandards and bearing its precision seal.The correction for thesieve used in this test shall be determined by sieving tests madein conformity with the procedure of this test method.Identicalsamples shall be sieved through the reference sieve and the testsieve.Test materials shall be
14、chosen so that 5 to 10%of thematerial will be retained on the reference sieve.The differencebetween the percentage residue on the reference sieve and thaton the test sieve is the amount of correction which shall bealgebraically added to,or subtracted from,the correction forthe reference sieve to obt
15、ain the final correction(Note 1).TheNo.40 sieve need not be calibrated.NOTE1For example,when comparing the reference sieve with a testsieve,should 8.5 g be retained on the reference sieve and 7.5 g on the testsieve,the total correction for the test sieve would then be 8.5 7.5,or+1.0.4.3 DryerA suita
16、ble means for drying the sieves and slipsample,without exceeding a temperature of 250F(122C),shall be provided.No dryer is needed for sieve tests ofdry-milled enamel.4.4 Mechanically Operated Sieve Shaker The mechanicalshaking device shall be such as to produce a lateral and verticalmotion of the sieve,accompanied by a jarring action so as tokeep the sample moving continuously over the surface of thesieve.If a machine shaker is to be used,the thoroughness ofsieving shall be tested by comparing a
