1、Designation: D7487 08D7487 13Standard 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 re
2、vision. 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, st
3、ringgel time (pull time), tack free time, settle back, and free rise density of polyurethane foam formulations using a cup foam test.1.2 Typical definitions, terms, and techniques are described; including procedures for mixing and transferring samples to thefoaming container; and data gathering and
4、evaluation. However, agreement between the customer and the testing laboratory forall these items must be obtained prior to use.1.3 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.1.4 This standard does not purport to address
5、all of the safety concerns, if any, associated with its use. It is the responsibilityof the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatorylimitations prior to use.NOTE 1There is no known ISO equivalent to this standard.2. Refe
6、renced Documents2.1 ASTM Standards:2D883 Terminology Relating to PlasticsE691 Practice for Conducting an Interlaboratory Study to Determine the Precision of a Test Method3. Terminology3.1 DefinitionsTerminology used in this practice follows that defined in Terminology D883.3.2 Definitions of Terms S
7、pecific to This Standard:3.2.1 cream time (initiation time)the time between the start of mixing and the point at which fine bubbles begin to appear.3.2.2 top of cup timethe time at which the crown of the rising foam reaches the plane of the top of the cup.3.2.3 free rise time (end of rise time)the t
8、ime at which the foam 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 surface of the foamwhen the surface is touched by the edge of a tongue depressor or similar implement.3.2.5 tack free timethe time at
9、 which the surface of the foam can be touched with a gloved finger or tongue depressor withoutsticking.3.2.6 free rise densitythe density in kg/m3 of a polyurethane 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
10、 time3.2.9 % settle back (% recession, % sigh back, or % sink back)percentage decrease from free rise height to final height3.2.10 resin blend (formulated polyol)complete ingredient formulation without the isocyanate1 This practice is under the jurisdiction of ASTM Committee D20 on Plastics and is t
11、he direct responsibility of Subcommittee D20.22 on Cellular Materials - Plastics andElastomers.Current edition approved Nov. 15, 2008Nov. 1, 2013. Published November 2008November 2013. DOI: 10.1520/D7487-08.Originally approved in 2008. Last previousedition approved in 2008 as D7487 - 08. DOI:10.1520
12、/D7487-13.2 For referencedASTM standards, visit theASTM website, www.astm.org, or contactASTM Customer Service at serviceastm.org. For Annual Book of ASTM Standardsvolume information, refer to the standards Document Summary page on the ASTM website.This document is not an ASTM standard and is intend
13、ed only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Becauseit may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current
14、 versionof the standard as published by ASTM is to be considered the official document.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States14. Summary of Practice4.1 Specific events (cream time, initiation time, top of cup time, free rise
15、time, free rise height, string gel time, and tack freetime) from a polyurethane foamed in a cup are measured to 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. An estimation of bias is not
16、given because there is no suitable referencemethod.5. Significance and Use5.1 General Utility:5.1.1 It is useful to verify catalyst levels in a resin blend or a polyurethane system.5.1.2 This practice is suitable for research, quality control, specification testing, and process control.5.2 Limitatio
17、ns:5.2.1 Several of the measured parameters are subjective. Therefore, operator-to-operator variability and lab-to-lab variabilitycan be much higher than that of a single operator.5.2.2 The variability of this practice is dependent on the consistency of mixing of the reactants.5.2.3 The estimation o
18、f precision in this practice is based on typical formulations for rigid and flexible foams. Formulations withfaster reaction times will likely have greater variability, particularly cream time (initiation time). Formulations with slower reactiontimes will likely have greater variability in the measu
19、rement of free rise time.5.2.4 It is possible that low-level (ppm, ppb) ingredient contamination will not be detectable using this practice. Confirmationof such contamination will potentially require large-scale ( 20 litres) tests and is out of the scope of this practice.6. Apparatus6.1 Stirrer for
20、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 the blade must be large enough to cleanly cut through the risen foam at the top of the cup.6.4 Thermometersaccurate to 60.5C.6.5 Stopwatchcapable of measur
21、ing to 0.1 s.6.6 Balancecapacity of 100 g and capable of weighing to 0.1 g.6.7 Tachometercapable of measuring to the nearest rpm.6.8 Rulercapable of measuring to 1 mm.7. Test Conditions7.1 Since isocyanates react with moisture, keep laboratory humidity low, preferably around 50 % relative humidity.7
22、.2 Some of the parameters are influenced by atmospheric pressure. The quantitative influence is not known at this time. Ifresults are to be compared between laboratories located at significantly different elevations above sea level, it is advisable tomeasure the barometric pressure and develop a sui
23、table, empirical correction factor. (WarningMany diisocyanates are knownor suspected sensitizers. Over-exposure to diisocyanates can lead to adverse health effects which may include the development ofoccupational asthma and other respiratory, skin, and eye effects. Engineering controls, or personal
24、protective equipment, or both,including respiratory, skin, and eye protection, are to be used when there is a potential for over-exposure to diisocyanates. Theproduct suppliers MaterialSafety Data Safety Sheet (MSDS)(SDS) provides more detailed information about potential adversehealth effects and o
25、ther important safety and handling information. Always follow the specific instructions provided on theMSDS.SDS.)8. Procedure8.1 Check the stirrer speed with a tachometer and rotation direction in air with no load and turn the stirrer off after checking.8.2 Weigh an empty cup and record the weight.8
26、.3 Weigh reactants into the cup in accordance with previously established order of addition.NOTE 2Ensure that the temperature of the reactants is as specified prior to use.NOTE 3This cup is then nested into another cup to prevent spilling chemicals in case the propeller cuts the first cup. Some prac
27、titioners use plasticcups 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.D7487 1328.4 Immerse the stirrer blade completely to a starting position in contact with the bottom of the cup and retract it slightly.8.5 Simultan
28、eously, turn on the mixer switch, and start the stopwatch.NOTE 5In some cases, it is better to ramp up the mixer speed. Such modifications need to be established prior to testing.8.6 Mix the materials for a specified time then, remove the cup from the spinning mixing blade.NOTE 6Care must be taken t
29、o remove the cup slowly so that splashing of 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 the cup in a fume hood and record the times as defined in Section 3.8.8 Clean the stirrer blade thoroughly after each tes
30、t.8.9 After a specified time, cut off the crown of the foam as close to the top edge of the paper cup as possible.8.10 Record the weight of the cup plus remaining foam to the 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 Densit
31、y can be determined is as follows:9.1.1.1 Calculate the weight of the foam in the cup as follows:Wfoam! 5Wcup1cut foam! 2Wempty cup!#where:W(foam) = weight in grams of the remaining foam in the cupW(cup + cut foam) = weight in grams of the cup plus remaining foamW(empty cup) = weight in grams of the
32、 empty cup9.1.1.2 Calculate the Free Rise Density as follows:Free Rise Density kg/m3!5g/L 5Wfoam!/Vcup!where:W(foam) = weight in grams of the remaining foam in the cupV(cup) = the volume of the cup in litres9.1.2 An example of how to calculate % Settle Back as follows:%Settle Back5Hrise2Hfinal! 3100
33、%/Hrisewhere:Hrise = free rise height of foam in millimetresHfinal = final foam height in millimetres10. Report10.1 Report all time results as previously agreed, typically to the nearest whole second.10.2 Report Free Rise Density as previously agreed, generally, Free Rise Density is reported to two
34、decimal places.10.3 Report % Settle Back as previously agreed, generally to the nearest percent.11. Precision and Bias11.1 PrecisionAttempts to develop a precision and bias statement for this practice have not been successful. For this reason,only estimates of data on precision and bias can be given
35、. Because this practice does not contain an acceptable numerical precisionand bias statement, it shall not be used as a referee test method in case of dispute.Anyone wishing to participate in the developmentof precision and bias data is to contact the Chairman, Subcommittee D20.22 (Section D20.22.01
36、),ASTM, 100 Barr Harbor Drive,West Conshohocken, PA 19428.12. Keywords12.1 cream time; cup test; foam testing; formulated polyol; free rise density; free rise height; free rise time; initiation time;isocyanate; polyurethane; pull time; raw material; resin blend; settle back; sigh back; sink back; st
37、ring gel time; tack free time;top of cup timeD7487 133APPENDIX(Nonmandatory Information)X1. EXAMPLE OF CUP FOAM TEST CONDITIONS FOR POLYURETHANE FOAM FORMULATIONSX1.1 ScopeX1.1.1 Information provided in this non-mandatory appendix is given to provide the reader with a more-specific example of testco
38、nditions as defined by one company. Other acceptable test conditions are possible.X1.2 Referenced DocumentsX1.2.1 Referenced documents for this appendix are as listed in Section 2.1.X1.3 TerminologyX1.3.1 Terminology for this appendix are as defined in Section 3.X1.4 ApparatusNOTE X1.1Specific suppl
39、iers and part numbers are provide below as examples and are based upon one companys experience. Other suppliers areavailable. Users of this practice are encouraged to identify suppliers and parts that meet their specific needs for this practice.X1.4.1 Stirring stationStandard ServoDyne system (catal
40、og #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 Blade Propeller3-in. diameter by 516-in. diameter bore (catalog #J-4553-68), available from Cole ParmerInstru
41、ment Co.X1.4.1.2 Stainless Steel Shaft12-in. long by 516-in. diameter, cut to 7-in. length (catalog #J-4553-50), available from ColeParmer Instrument Co.X1.4.2 Paper Cups1 L unwaxed, Dixie cup No. 2195, available from Dixie/Marathon.X1.4.3 Electric KnifeBlack or through the ASTM website(www.astm.org
42、). Permission rights to photocopy the standard may also be secured from the ASTM website (www.astm.org/COPYRIGHT/).TABLE X1.6 Estimated Precision for Free Rise TimeFree Rise Density in kg/m3Material Average SrA SRB rC RD nErigid resin blend 62.1 6.89 10.7 19.3 30.0 4flexible resin blend 123 10.9 18.
43、4 30.6 51.5 4ASr = within-laboratory standard deviation of the replicates.BSR = between-laboratory standard deviation of the averages.Cr = within-laboratory repeatability limit = 2.8*Sr.D R = between-laboratory reproducibility limit = 2.8*SR.En = number of laboratories contributing valid data for this material.D7487 137
