ASTM_C_242_-_18.pdf

Designation:C24218Standard Terminology ofCeramic Whitewares and Related Products1This standard is issued under the fixed designation C242;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.1.Scope1.1 This terminology pertains to the terminology used inceramic whitewares and related products.1.2 Words adequately defined in standard dictionaries arenot included.Included are words that are peculiar to thisindustry.Double words,hyphenated words,or phrases arelisted alphabetically under the first word;additional importantwords are cross-referenced.1.3For definitions of terms relating to surface imperfec-tions on ceramics,refer to Terminology F109.1.4 This international standard was developed in accor-dance with internationally recognized principles on standard-ization established in the Decision on Principles for theDevelopment of International Standards,Guides and Recom-mendations issued by the World Trade Organization TechnicalBarriers to Trade(TBT)Committee.2.Referenced Documents2.1 ASTM Standards:2D1129 Terminology Relating to WaterE180 Practice for Determining the Precision of ASTMMethods for Analysis and Testing of Industrial and Spe-cialty Chemicals(Withdrawn 2009)3F109 Terminology Relating to Surface Imperfections onCeramicsF465 Practice for Developing Precision and Accuracy Dataon ASTM Method for the Analysis of Meat and MeatProducts(Withdrawn 1993)32.2 British Standard:4BS 2955 Glossary of Terms Relating to Powders3.Terminologyabsolute or true densitySee absolute or true density underdensity.absorbancethe logarithm of that fraction of an incident lightbeam that is dissipated in the sample,being neither trans-mitted nor reflected.absorbed moisturewater held mechanically in the materialand having physical properties not substantially differentfrom ordinary water at the same temperature and pressure.absorption(1)the relationship of the weight of the waterabsorbed by a ceramic specimen,subjected to prescribedimmersion procedure,to the weight of the dry specimen.(2)the capacity of a substance to take up a substance,usually a liquid or gas,with the formation of an apparentlyhomogeneous mixture.adsorptionthe capacity of a substance to accept and retainon its surface a layer of another substance,usually a gas ora liquid.agglomeratea jumbled mass or collection of two or moreparticles or aggregates,or a combination thereof,heldtogether by relatively weak cohesive forces caused by weakchemical bonding or an electrostatic surface charge gener-ated by handling or processing.DISCUSSIONCommon usage in powder technology(and BritishStandard BS 2955)has the terms“aggregate”and“agglomerate”interchanged in meaning from the definitions presented here,and caremust be taken to determine in context which definition is in use.aggregatea dense mass of particles held together by strongintermolecular or atomic cohesive forces that is stable tonormal mixing techniques,including high-speed stirring andultrasonics.alumina porcelainSee alumina porcelain under porcelain.alumina whitewareSee alumina whiteware under ceramicwhiteware.andalusitea polymorph,along with sillimanite and kyanite,of composition Al2O3SiO2which on firing dissociates toyield principally mullite.apparent or pycnometric densitySee apparent or pycnomet-ric density under density.apparent porositySee apparent porosity under porosity.1This terminology is under the jurisdiction of ASTM Committee C21 onCeramic Whitewares and Related Productsand is the direct responsibility ofSubcommittee C21.01 on Editorial and Terminology.Current edition approved Feb.1,2018.Published February 2015.Originallyapproved in 1950.Last previous edition approved in 2015 as C242 15.DOI:10.1520/C0242-18.2For 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.3The last approved version of this historical standard is referenced onwww.astm.org.4Available from British Standards Institute,2 Park St.,London,EnglandW1A 2B5.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United StatesThis international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for theDevelopment of International Standards,Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade(TBT)Committee.1 average particle sizea single value representing the entireparticle-size distribution.DISCUSSIONIt is essential to specify the basis under which theaverage is obtained.ball claya secondary clay,commonly characterized by thepresence of organic matter,high pla