1、Designation: D7487 18Standard 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.
2、A number 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
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 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 thesafe
5、ty concerns, if any, associated 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.NOTE 1There is no known ISO equivalent to this standard.1.5
6、 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 Tr
7、ade (TBT) Committee.2. Referenced 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
8、.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 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 (
9、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 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 f
10、ree 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 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 fo
11、am after specified time3.2.9 % settle back (% 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 ti
12、me, 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 blend composition or levels of ingredients informulations used to make polyurethane foams.4.2 An estimation of the method precision is given.
13、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 catalyst levels in a resin blend ora polyurethane system.1This practice is under the jurisdiction ofASTM Committee D20 on Plastics andis the direct r
14、esponsibility of Subcommittee D20.22 on Cellular Materials - 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 w
15、ebsite, 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.*A Summary of Changes section appears at the end of this standardCopyright ASTM International, 100 Barr Harbo
16、r 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 Recommendatio
17、ns issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.15.1.2 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 vari
18、ability and lab-to-lab vari-ability can 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. Form
19、ulationswith faster reaction times will likely have greater variability,particularly cream time (initiation time). Formulations withslower 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 wi
20、ll not be detectable using this practice.Confirmation of such contamination will potentially requirelarge-scale ( 20 liters) 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 ste
21、el shaft.6.2 Cups6.3 KnifeCutting length of 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 tothe nearest 0.1 g.6.7 TachometerCa
22、pable of measuring to the nearest rpm.6.8 RulerCapable of measuring to the nearest 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 quantitativ
23、e influence is not known at this time.If results are to be compared between laboratories located atsignificantly different elevations above sea level, it is advisableto measure the barometric pressure and develop a suitable,empirical correction factor. (WarningDiisocyanates are eye,skin, and respira
24、tory irritants at concentrations above theoccupational exposure limit (TLV or PEL). Diisocyanates cancause skin and respiratory sensitization (asthma) in somepeople. Once sensitized, it is essential to limit further exposureto diisocyanates. Use a combination of engineering controlsand personal prot
25、ective equipment, including respiratory, skinand eye protection, to prevent over-exposure to diisocyanates.Consult the product suppliers Safety Data Sheet (SDS) formore detailed information about potential health effects andother specific safety and handling instructions for the product)8. Procedure
26、8.1 Check the stirrer speed with a 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
27、of the reactants is as specifiedprior 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 seco
28、nd cup,results may vary.8.4 Immerse 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 nee
29、d to be established prior to testing.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
30、 and then remove the cup.8.7 Place 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 cu
31、p plus remaining foam tothe nearest 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!5Wcup1cut foam!2 Wempty cup!#where:W(foam)=
32、weight in grams of the remaining foam inthe cupW(cup + cut foam)= weight in grams of the cup plus remainingfoamW(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
33、 foam in the cupV(cup)= the volume of the cup in litresD7487 1829.1.2 An example of how to calculate % Settle Back asfollows:% Settle Back 5 Hrise2 Hfinal! 3100%/Hrisewhere:Hrise= free rise height of foam in millimetersHfinal= final foam height in millimeters10. Report10.1 Report all time results as
34、 previously agreed, typicallyto the nearest whole second.10.2 Report Free Rise Density as previously agreed,generally, Free Rise Density is reported to two decimal places.10.3 Report % Settle Back as previously agreed, generallyto the nearest percent.11. Precision and Bias11.1 PrecisionAttempts to d
35、evelop a precision and biasstatement 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
36、of dispute. Anyone wishing toparticipate in the development of precision and bias data is tocontact the Chairman, Subcommittee D20.22 (SectionD20.22.01), ASTM, 100 Barr Harbor Drive, WestConshohocken, PA 19428.12. Keywords12.1 cream time; cup test; foam testing; formulated polyol;free rise density;
37、free rise height; free rise time; 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 FORMULATI
38、ONSX1.1 ScopeX1.1.1 Information 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
39、 listedin Section 2.1.X1.3 TerminologyX1.3.1 Terminology for this appendix are as defined inSection 3.X1.4 ApparatusNOTE X1.1Users of this practice are encouraged to identify suppliersand parts that meet their specific needs for this practice.X1.4.1 Stirring stationStandard ServoDyne electronicmixer
40、 system, electronic digital timer, available from ColeParmer Instrument Company, 625 East Bunker Ct., VernonHills, IL 60061, United States, http:/ Three Blade Propeller3-in. diameter by516-in.diameter bore.X1.4.1.2 316 Stainless Steel Shaft12-in. long by516-in.diameter, cut to 7-in. length.X1.4.2 Pa
41、per Cups63 oz. unwaxed paper buckets.X1.4.3 Electric KnifeCutting length of the blade must begreater than the upper inner diameter of the cup.X1.4.4 ThermometersAccurate to 60.5C.X1.4.5 BeakersPolypropylene, 50-mL and 250-mL vol-umes.X1.4.6 Stop Watch or timerPreferably with greater thanfive memorie
42、s.X1.4.7 Tongue Depressors34 in. by 6 in.X1.4.8 BalanceCapacity of 100 g and capable of weigh-ing to the nearest 0.1 g.X1.5 ReagentsX1.5.1 Methylene Chloride or Acetone: Reagent grade.X1.6 ProcedureX1.6.1 Check the stirrer speed with a tachometer androtation direction in air with no load. Set the st
43、irrer speed at3000 rpm and the rotation such that the flow of air isdownward. Turn the stirrer off.X1.6.2 Weigh a cup and record the weight. Nest this cupinto another cup.X1.6.3 Wet-tare a 50-mL beaker with isocyanate. (Fill theempty beaker to the weight of 23.0 g for a rigid foam or 16.0g for a fle
44、xible foam. Quickly pour the isocyanate into a wastecontainer and drain the contents for three seconds. Set thebeaker upright and tare the wet beaker.) This procedureapproximately compensates for the amount of isocyanate thatwill not drain from the beaker when the isocyanate sample istransferred to
45、the tared cup containing the polyol.X1.6.4 Add the required amount of isocyanate, 23.0 g for arigid foam or 16.0 g for a flexible foam to the wet-tared beakerand record the weight to the nearest 0.1 g.D7487 183X1.6.5 Add the required amount of resin blend, 20 g for arigid foam or 35 g for a flexible
46、 foam, to the nested cups andrecord the weight to the nearest 0.1 g. Start mixing within oneminute of adding the resin blend to the cup.X1.6.6 Pour the isocyanate for three seconds into the papercups containing the resin blend.X1.6.7 Immerse the stirrer blade completely to a startingposition near th
47、e bottom of the cup.X1.6.8 Simultaneously, turn on the mixer switch, and startthe stopwatch. Mix the materials for five seconds.At the end offive seconds, remove the cup from the spinning mixing blade.X1.6.9 Place the cup in a fume hood and observe. Recordthe characteristic times as defined in Secti
48、on 3.X1.6.10 Clean the stirrer blade thoroughly after each test,with methylene chloride at 300 rpm.X1.6.11 Approximately 15 minutes after the start of mixing,use an electric knife to cut off the crown of the foam as closeto the top edge of the paper cup as possible.X1.6.12 Record the weight of the c
49、up plus remaining foamto the nearest 0.1 g.X1.7 CalculationsX1.7.1 Calculations for this appendix are as defined inSection 9.X1.8 Precision and BiasX1.8.1 A limited round robin was performed with fourlaboratories within a single company. Tables X1.1-X1.6 arebased on this round robin which was conducted in 2004 and arein general accordance with Practice E691, involving twomaterials tested by two operators in each of four laboratories.Each laboratory made duplicate determinations on each mate-rial on each
