ASTM_C_374_-_14_2015e1.pdf

Designation:C37414(Reapproved 2015)1Standard Test Methods forFusion Flow of Porcelain Enamel Frits(Flow-ButtonMethods)1This standard is issued under the fixed designation C374;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 indicates the year of last reapproval.Asuperscript epsilon()indicates an editorial change since the last revision or reapproval.1NOTESections 3 and 8 corrected editorially in May 2015.INTRODUCTIONThis test provides a procedure to compare the fluidity of a glass frit or a porcelain enamel powderto a standard reference material at a fixed temperature above the samples glass temperature.1.Scope1.1 These test methods cover evaluation of the relativefusion flow characteristics of samples of a given porcelainenamel frit by comparison with an established standard for thatfrit.1.2 Two test methods are included,differing only in certaindetails of the samples and in the apparatus and procedure forpreparation of test specimens.Both test methods give equallyreproducible results and provide a satisfactory basis for com-parison of fusion flow of the sample with that of the establishedstandard.1.2.1 Test Method A employs granular particles of frit towhich a bonding agent has been added.Button specimens areformed under high pressure in a hydraulic press.1.2.2 Test Method B employs crushed,sized particles of fritto which a bonding agent has been added.Button specimensare formed in a steel mold by hand.1.3 The values stated in inch-pound units are to be regardedas standard.The values given in parentheses are mathematicalconversions to SI units that are provided for information onlyand are not considered standard.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 applica-bility of regulatory limitations prior to use.2.Referenced Document2.1 ASTM Standards:2E11 Specification for Woven Wire Test Sieve Cloth and TestSievesTEST METHOD A3.Apparatus3.1 Mortar,of hard steel,resistant to abrasion by theporcelain enamel frit,and conforming to the dimensions shownin Fig.1.NOTE1Suitable mortars are available commercially under the desig-nation“tool steel crushing mortar.”3.2 SievesNo.12(1.70-mm)and No.200(75-m)sievesconforming to Specification E11.3.3 Hydraulic Press,capable of developing 3500-lbf(15 600 N)force(Fig.2).3.4 Steel Mold Assembly,consisting of a die and plunger,and having an inside diameter of12in.(12.7 mm)over itslength of 218in.(54 mm)as illustrated in Fig.3.3.5 Fusion Flow Rack,preferably constructed of heat-resisting alloy and conforming to the detailed requirementsshown in Fig.4.4.Sample4.1 A representative sample of the frit to be tested shall beobtained,mixed thoroughly,and reduced by quartering toabout 25 g.This sample shall be crushed in a hard steel mortarto pass a No.12(1.70 mm)sieve and be retained on a No.200(75 m)sieve.1These 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.Current edition approved May 1,2015.Published May 2015.Originallyapproved in 1955.Last previous edition approved in 2014 as C374 14.DOI:10.1520/C0374-14R15E01.2For referenced ASTM standards,visit the ASTM website,www.astm.org,orcontact ASTM Customer Service at serviceastm.org.For Annual Book of ASTMStandards 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 4.2 For wet-ground enamels the sample shall be evaporatedto dryness in an evaporation dish.After cooling,the driedenamel shall be loosened and again pulverized using a pestleand mortar or similar apparatus.4.3 Dry ground samples of frit,ready-to-use powder,orenamel powder for dry electrostatic application may also betested.5.Test Specimen5.1 Weigh 3.5 6 0.05-g samples of the standard frit and ofthe material to be tested and thoroughly mix each of thesesamples with four or five drops of a 1%gum arabic solution.Mold fusion button test specimens of the standard and of thesample as directed in 5.2.For dry electrostatic powder samples,use four to five drops of acetone instead of the aqueous gumarabic solution.5.2 Place the sample in the steel mold.Place the moldassembly containing the sample in a hydraulic press and bringthe press up to 3000 to 3500 lbf(13.3 to 15.6 kN)total load,and immediately release(Fig.2).Force the formed button outof the mold with the plunger,taking care not to damage thebutton in any way that might change the dimensions.5.3 Dry the test specimens in a suitable oven at 212F(100C)for 1 h.NOTE2Special care must be exercised in drying buttons formed bythis method,b