1、Designation: D 7487 08Standard Practice forPolyurethane Raw Materials: Polyurethane Foam Cup Test1This standard is issued under the fixed designation D 7487; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision
2、. 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 practice covers the determination of cream time(initiation time), top of cup time, free rise time, free rise height,string gel
3、 time (pull time), 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
4、.However, agreement between the customer and the testinglaboratory for all these items must be obtained prior to use.1.3 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-priat
5、e safety and health practices and determine the applica-bility of regulatory limitations prior to use.NOTE 1There is no known ISO equivalent to this standard.2. Referenced Documents2.1 ASTM Standards:2D 883 Terminology Relating to PlasticsE 691 Practice for Conducting an Interlaboratory Study toDete
6、rmine the Precision of a Test Method3. Terminology3.1 DefinitionsTerminology used in this practice followsthat defined in Terminology D 883.3.2 Definitions of Terms Specific to This Standard:3.2.1 cream time (initiation time)the time between thestart of mixing and the point at which fine bubbles beg
7、in 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 thefoam stops expanding as observed visually.3.2.4 string gel time (pull time)time at which long“strings” of tacky material
8、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 of thefoam can be touched with a gloved finger or tongue depressorwithout sticking.3.2.6 free rise densitythe density in
9、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 back (% recession, % sigh back, or % sinkback)percentage decrease from free rise height to finalheight3.2.10 resin blend
10、(formulated polyol)complete ingredi-ent formulation without the isocyanate4. Summary of Practice4.1 Specific events (cream time, initiation time, top of cuptime, free rise time, free rise height, string gel time, and tackfree time) from a polyurethane foamed in a cup are measuredto verify the resin
11、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 suitablereference method.5. Significance and Use5.1 General Utility:5.1.1 It is useful to verify catalys
12、t levels in a resin blend ora polyurethane system.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-to-operator variability and lab-to-lab vari-ability c
13、an be much higher than that of a single operator.5.2.2 The variability of this practice is dependent on theconsistency of mixing of the reactants.5.2.3 The estimation of precision in this practice is based ontypical formulations for rigid and flexible foams. Formulationswith faster reaction times wi
14、ll likely have greater variability,particularly cream time (initiation time). Formulations with1This practice is under the jurisdiction ofASTM Committee D20 on Plastics andis the direct responsibility of Subcommittee D20.22 on Cellular Materials - Plasticsand Elastomers.Current edition approved Nov.
15、 15, 2008. Published November 2008.2For 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.1Copyright ASTM Internatio
16、nal, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.slower reaction times will likely have greater variability in themeasurement of free rise time.5.2.4 It is possible that low-level (ppm, ppb) ingredientcontamination will not be detectable using this practice.Co
17、nfirmation of such contamination will potentially requirelarge-scale ( 20 litres) tests and is out of the scope of thispractice.6. Apparatus6.1 Stirrer for Mixing:6.1.1 Stirring motor,6.1.2 Propeller or other type of mixing apparatus, and6.1.3 Stainless steel shaft.6.2 Cups6.3 KnifeCutting length of
18、 the blade must be large enoughto cleanly cut through the risen foam at the top of the cup.6.4 Thermometersaccurate to 60.5C.6.5 Stopwatchcapable of measuring to 0.1 s.6.6 Balancecapacity of 100 g and capable of weighing to0.1 g.6.7 Tachometercapable of measuring to the nearest rpm.6.8 Rulercapable
19、of measuring to 1 mm.7. Test Conditions7.1 Since isocyanates react with moisture, keep laboratoryhumidity low, preferably around 50 % relative humidity.7.2 Some of the parameters are influenced by atmosphericpressure. The quantitative influence is not known at this time.If results are to be compared
20、 between laboratories located atsignificantly different elevations above sea level, it is advisableto measure the barometric pressure and develop a suitable,empirical correction factor. (WarningMany diisocyanatesare known or suspected sensitizers. Over-exposure to diisocy-anates can lead to adverse
21、health effects which may include thedevelopment of occupational asthma and other respiratory,skin, and eye effects. Engineering controls, or personal protec-tive equipment, or both, including respiratory, skin, and eyeprotection, are to be used when there is a potential forover-exposure to diisocyan
22、ates. The product suppliers Mate-rial Data Safety Sheet (MSDS) provides more detailed infor-mation about potential adverse health effects and other impor-tant safety and handling information. Always follow thespecific instructions provided on the MSDS.)8. Procedure8.1 Check the stirrer speed with a
23、tachometer and rotationdirection in air with no load and turn the stirrer off afterchecking.8.2 Weigh an empty cup and record the weight.8.3 Weigh reactants into the cup in accordance with previ-ously established order of addition.NOTE 2Ensure that the temperature of the reactants is as specifiedpri
24、or to use.NOTE 3This cup is then nested into another cup to prevent spillingchemicals in case the propeller cuts the first cup. Some practitioners useplastic cups with thicker walls and omit the second cup.NOTE 4If users elect to mix in one cup and pour into a second cup,results may vary.8.4 Immerse
25、 the stirrer blade completely to a startingposition in contact with the bottom of the cup and retract itslightly.8.5 Simultaneously, turn on the mixer switch, and start thestopwatch.NOTE 5In some cases, it is better to ramp up the mixer speed. Suchmodifications need to be established prior to testin
26、g.8.6 Mix the materials for a specified time then, remove thecup from the spinning mixing blade.NOTE 6Care must be taken to remove the cup slowly so that splashingof the reaction mixture does not occur. If appropriate, stop the mixer at theend of the specified time and then remove the cup.8.7 Place
27、the cup in a fume hood and record the times asdefined in Section 3.8.8 Clean the stirrer blade thoroughly after each test.8.9 After a specified time, cut off the crown of the foam asclose to the top edge of the paper cup as possible.8.10 Record the weight of the cup plus remaining foam tothe nearest
28、 0.1 g.9. Calculation9.1 Calculate the Free Rise Density and express as kg/m3.9.1.1 An example of how Free Rise Density can be deter-mined is as follows:9.1.1.1 Calculate the weight of the foam in the cup asfollows:Wfoam!5 Wcup 1 cut foam! Wempty cup!#where:W(foam)= weight in grams of the remainingf
29、oam in the cupW(cup + cut foam)= weight in grams of the cup plusremaining foamW(empty cup)= weight in grams of the empty cup9.1.1.2 Calculate the Free Rise Density as follows:Free Rise Density kg/m3! 5 g/L 5 Wfoam!/ Vcup!where:W(foam)= weight in grams of the remaining foam in thecupV(cup)= the volum
30、e of the cup in litres9.1.2 An example of how to calculate % Settle Back asfollows:% Settle Back 5 Hrise Hfinal! 3 100%/Hrisewhere:Hrise= free rise height of foam in millimetresHfinal= final foam height in millimetres10. Report10.1 Report all time results as previously agreed, typicallyto the neares
31、t whole second.10.2 Report Free Rise Density as previously agreed, gener-ally, Free Rise Density is reported to two decimal places.10.3 Report % Settle Back as previously agreed, generallyto the nearest percent.D748708211. Precision and Bias11.1 PrecisionAttempts to develop a precision and biasstate
32、ment for this practice have not been successful. For thisreason, only estimates of data on precision and bias can begiven. Because this practice does not contain an acceptablenumerical precision and bias statement, it shall not be used asa referee test method in case of dispute. Anyone wishing topar
33、ticipate in the development of precision and bias data is tocontact the Chairman, Subcommittee D20.22 (SectionD20.22.01), ASTM, 100 Barr Harbor Drive, West Consho-hocken, PA 19428.12. Keywords12.1 cream time; cup test; foam testing; formulated polyol;free rise density; free rise height; free rise ti
34、me; initiation time;isocyanate; polyurethane; pull time; raw material; resin blend;settle back; sigh back; sink back; string gel time; tack free time;top of cup timeAPPENDIX(Nonmandatory Information)X1. EXAMPLE OF CUP FOAM TEST CONDITIONS FOR POLYURETHANE FOAM FORMULATIONSX1.1 ScopeX1.1.1 Informatio
35、n provided in this non-mandatory appen-dix is given to provide the reader with a more-specific exampleof test conditions as defined by one company. Other acceptabletest conditions are possible.X1.2 Referenced DocumentsX1.2.1 Referenced documents for this appendix are as listedin Section 2.1.X1.3 Ter
36、minologyX1.3.1 Terminology for this appendix are as defined inSection 3.X1.4 ApparatusNOTE X1.1Specific suppliers and part numbers are provide below asexamples and are based upon one companys experience. Other suppliersare available. Users of this practice are encouraged to identify suppliersand par
37、ts that meet their specific needs for this practice.X1.4.1 Stirring stationStandard ServoDyne system (cata-log #J-4440-00), electronic digital time (115 volt AC; catalog#J-8683-50), available from Cole Parmer Instrument Co., Intl.Sales Div., 7425 N. Oak Park Avenue, Niles, IL 60714.X1.4.1.1 Three Bl
38、ade Propeller3-in. diameter by516-in.diameter bore (catalog #J-4553-68), available from ColeParmer Instrument Co.X1.4.1.2 Stainless Steel Shaft12-in. long by516-in. diam-eter, cut to 7-in. length (catalog #J-4553-50), available fromCole Parmer Instrument Co.X1.4.2 Paper Cups1 L unwaxed, Dixie cup No
39、. 2195,available from Dixie/Marathon.X1.4.3 Electric KnifeBlack or through the ASTM website(www.astm.org).TABLE X1.6 Estimated Precision for Free Rise TimeFree Rise Density in kg/m3Material Average SrASRBrCRDnErigid resin blend 62.1 6.89 10.7 19.3 30.0 4flexible resin blend 123 10.9 18.4 30.6 51.5 4
40、ASr= within-laboratory standard deviation of the replicates.BSR= between-laboratory standard deviation of the averages.Cr = within-laboratory repeatability limit = 2.8*Sr.DR = between-laboratory reproducibility limit = 2.8*SR.En = number of laboratories contributing valid data for this material.D7487085
