1、Designation:D748718Standard Practice forPolyurethane Raw Materials:Polyurethane Foam Cup Test1This standard is issued under the fixed designation D7487;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revision,the year of last revision.A numbe
2、r in parentheses indicates the year of last reapproval.Asuperscript epsilon()indicates an editorial change since the last revision or reapproval.1.Scope*1.1 This practice covers the determination of cream time(initiation time),top of cup time,free rise time,free rise height,string gel time(pull time
3、),tack free time,settle back,and freerise density of polyurethane foam formulations using a cupfoam test.1.2 Typical definitions,terms,and techniques are described;including procedures for mixing and transferring samples tothe foaming container;and data gathering and evaluation.However,agreement bet
4、ween the customer and the testinglaboratory for all these items must be obtained prior to use.1.3 The values stated in SI units are to be regarded asstandard.No other units of measurement are included in thisstandard.1.4 This standard does not purport to address all of thesafety concerns,if any,asso
5、ciated with its use.It is theresponsibility of the user of this standard to establish appro-priate safety,health,and environmental practices and deter-mine the applicability of regulatory limitations prior to use.NOTE1There is no known ISO equivalent to this standard.1.5 This international standard
6、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
7、 Documents2.1 ASTM Standards:2D883 Terminology Relating to PlasticsE691 Practice for Conducting an Interlaboratory Study toDetermine the Precision of a Test Method3.Terminology3.1 DefinitionsTerminology used in this practice followsthat defined in Terminology D883.3.2 Definitions of Terms Specific t
8、o This Standard:3.2.1 cream time(initiation time)the time between thestart of mixing and the point at which fine bubbles begin toappear.3.2.2 top of cup timethe time at which the crown of therising foam reaches the plane of the top of the cup.3.2.3 free rise time(end of rise time)the time at which t
9、hefoam stops expanding as observed visually.3.2.4 string gel time(pull time)time at which long“strings”of tacky material can be pulled away from the surfaceof the foam when the surface is touched by the edge of a tonguedepressor or similar implement.3.2.5 tack free timethe time at which the surface
10、of thefoam can be touched with a gloved finger or tongue depressorwithout sticking.3.2.6 free rise densitythe density in kg/m3of a polyure-thane foam prepared in an open cup.3.2.7 free rise heightheight of the foam at free rise time3.2.8 final heightheight of foam after specified time3.2.9%settle ba
11、ck(%recession,%sigh back,or%sinkback)percentage decrease from free rise height to final height3.2.10 resin blend(formulated polyol)complete ingredientformulation without the isocyanate4.Summary of Practice4.1 Specific events(cream time,initiation time,top of cuptime,free rise time,free rise height,s
12、tring gel time,and tackfree time)from a polyurethane foamed in a cup are measuredto verify the resin blend composition or levels of ingredients informulations used to make polyurethane foams.4.2 An estimation of the method precision is given.Anestimation of bias is not given because there is no suit
13、ablereference method.5.Significance and Use5.1 General Utility:5.1.1 It is useful to verify catalyst levels in a resin blend ora polyurethane system.1This practice is under the jurisdiction ofASTM Committee D20 on Plastics andis the direct responsibility of Subcommittee D20.22 on Cellular Materials-
14、Plasticsand Elastomers.Current edition approved Aug.1,2018.Published August 2018.Originallyapproved in 2008.Last previous edition approved in 2013 as D7487-131.DOI:10.1520/D7487-13E01.2For referenced ASTM standards,visit the ASTM website,www.astm.org,orcontact ASTM Customer Service at serviceastm.or
15、g.For Annual Book of ASTMStandards volume information,refer to the standards Document Summary page onthe ASTM website.*A Summary of Changes section appears at the end of this standardCopyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United StatesThis inte
16、rnational 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 5.1.2 This practice is suitable for research,quality control,specification testing,and process control.5.2 Limitations:5.2.1 Several of the measured parameters are subjective.Therefore,operator
