ASTM D3123-2009(2017) Standard Test Method for Spiral Flow of Low-Pressure Thermosetting Molding Compounds《低压热固性成型混合料螺旋流的标准试验方法》.pdf

1、Designation: D3123 09 (Reapproved 2017)Standard Test Method forSpiral Flow of Low-Pressure Thermosetting MoldingCompounds1This standard is issued under the fixed designation D3123; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, th

2、e 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 test method covers a procedure for measuring thespiral flow of thermosetting molding compounds (soft or

3、 verysoft) designed for molding pressures under 6.9 MPa (1000 psi).It is especially suited for those compounds used for encapsu-lation or other low pressure molding techniques. It involves theuse of a standard spiral flow mold in a transfer molding pressunder specified conditions of applied temperat

4、ure and pressurewith a controlled charge mass.1.2 The values stated in SI units are to be regarded asstandard.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-priate safet

5、y and health practices and determine the applica-bility of regulatory limitations prior to use.NOTE 1There is no known ISO equivalent to this test method.1.4 This international standard was developed in accor-dance with internationally recognized principles on standard-ization established in the Dec

6、ision 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:2D883 Terminology Relating to PlasticsD958 Practice for Determining Temperatures

7、of StandardASTM Molds for Test Specimens of Plastics (Withdrawn1995)3E105 Practice for Probability Sampling of Materials3. Terminology3.1 DefinitionsDefinitions in this test method are consis-tent with Terminology D883.4. Significance and Use4.1 The spiral flow of a thermosetting molding compound is

8、a measure of the combined characteristics of fusion underpressure, melt viscosity, and gelation rate under specificconditions.4.2 This test method is useful as a quality control test and asan acceptance criterion.4.3 This test method, by itself, is not a valid means forcomparing the moldability of s

9、imilar or different moldingcompounds because it cannot duplicate actual conditionsprevalent in different types of production molds.4.4 This test method is presently intended for use at atransfer pressure of 6.9 MPa (1000 psi) and a mold temperatureof 423 6 3 K (150 6 3C (302 6 5F).5. Apparatus5.1 Tr

10、ansfer Molding Press with a minimum 150 by150-mm (6 by 6-in.) platen area, transfer piston pressurepotentially greater than 6.9 MPa (1000 psi), sufficient clamppressure to prevent flashing, and a minimum plunger speed of25.4 mm (1 in.)/s without load. It is recommended that theplunger be equipped wi

11、th at least one peripheral sealinggroove. It is recommended that a pot diameter between 31.75and 44.45 mm (1.25 and 1.75 in.) be used whenever a choiceis possible.NOTE 2Preliminary evidence indicates that, in many cases, reasonablecorrelations may be achieved between laboratories using presses withd

12、ifferent pot diameters. Typical examples are presses with pot diameters of31.750, 38.100, and 44.450 mm (1.250, 1.500, and 1.750 in.). However, afew well-documented cases are recorded where differences in potdiameters, even within this listed range, have caused large differences inflow-length readin

13、gs. Therefore, for best interlaboratory correlation it isrecommended that identical pot diameters be used.5.2 Standard Spiral-Flow Mold shown in Fig. 1 shall beutilized.1This test method is under the jurisdiction of ASTM Committee D20 on Plasticsand is the direct responsibility of Subcommittee D20.3

14、0 on Thermal Properties(Section D20.30.08).Current edition approved Aug. 1, 2017. Published August 2017. Originallyapproved in 1972. Last previous edition approved in 2009 as D3123 - 09. DOI:10.1520/D3123-17.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Custome

15、r 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.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, Wes

16、t 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 Tr

17、ade Organization Technical Barriers to Trade (TBT) Committee.16. Materials6.1 Molding Compound:6.1.1 Any thermosetting molding compound with a spiralflow between 762 and 1270 mm (30 and 50 in.) as determinedat the standard temperature and pressure of this test can beevaluated.NOTE 3Since the only co

18、mmercially available molds are calibrated ininches, spiral-flow length will be reported in these units. Conversion to SIunits can readily be made by multiplying the flow length, in inches, by theappropriate conversion factor, 25.4 mm/in.NOTE 4There is considerable evidence that the test is usable ov

19、er awider range of flow lengths, but this has not yet been confirmed byinterlaboratory testing.6.1.2 FormThe form of the molding compound shall beloose powder or granules at 296 6 2 K (23 6 2C (73.4 63.6F).NOTE 5Preforms or pellets may be used if found necessary; however,flow length may be affected

20、by their use.7. Sampling7.1 Unless otherwise agreed upon between the seller andpurchaser, sampling shall be in accordance with Practice E105.Sampling, based on engineering principles, prior to packagingshall be considered an acceptable alternative.8. Conditioning8.1 ConditioningAll molding compounds

21、 shall be testedin “as-received” condition. For referee testing, all materialshall be shipped and stored in moisture-barrier containers.They shall be stored for a minimum of 24 h at the standardlaboratory temperature, before breaking the seal on the con-tainer. Take care to preserve the “as-received

22、” moisture contentand tests shall be made as soon as possible once the containerhas been opened. Alternative methods of conditioning samplesshall be mutually agreed upon between manufacturer andpurchaser.9. Test Conditions9.1 Spiral-Flow MoldThe mold shall be clean and freefrom any mold-release agen

23、ts or lubricants. Several prelimi-nary moldings shall be made with the material to be tested topurge the helical runner before beginning the test. Thisprocedure is essential when changing from one compound toanother and is recommended as a routine practice.9.2 Molding Conditions:9.2.1 TemperatureA t

24、emperature of 423 6 3 K (150 63C (302 6 5F) shall be maintained on the mold and transferplunger. Measure the temperature in accordance with theprocedures described in Practice D958 or by thermocouplesFIG. 1 Standard Spiral-Flow MoldD3123 09 (2017)2attached to the mold and plunger. The temperature sh

25、all beallowed to reach equilibrium by waiting at least 3 min betweenmoldings.9.2.2 Transfer PressureThe actual pressure applied to thecompound at the base of the pot shall be 6.90 6 0.17 MPa(1000 6 25 psi). In most presses, the gage pressure is notsufficiently accurate for determining transfer press

26、ure.Therefore, the force exerted by the plunger shall be measuredby some means such as an accurately calibrated direct-readingforce gage or proving ring. The actual transfer pressure is thencalculated as pascals (or pounds per square inch) by dividingthe force in newtons (or pounds-force) by the plu

27、nger area insquare metres (or square inches).9.2.3 Charge MassThe mass of the compound shall bedetermined empirically so that the thickness of the molded cull(cured compound on top of the sprue plate of the mold), aftertest, is between 3 and 3.5 mm (0.12 and 0.14 in.). Therelationship between the am

28、ount of compound and the dimen-sions of the transfer pot is critical in obtaining meaningful,reproducible spiral-flow values. The use of excessive amountsof compound will result in shorter, inconsistent spiral flows.For transfer pots 31.75 to 44.45 mm (1.25 to 1.75 in.) indiameter, 20 g of compound

29、is suggested as the starting chargemass.9.2.4 Transfer Plunger SpeedThe transfer plunger speedwithout load (as described in 5.1) shall be controlled between25 and 100 mm/s (1 and 4 in./s). The elapsed time betweeninsertion of the charge into the pot and the development ofpressure on the charge by th

30、e plunger shall be no more than 5seconds. Too long a dwell time before transferring will causeerratic results.9.2.5 Press Cure TimeSufficient cure time shall be used tofacilitate easy removal of the spiral from the mold. This timewill vary with the compound under test. Follow the manufac-turers reco

31、mmendations for cure when possible.9.2.6 Transfer Plunger GroovesIf the transfer plunger isequipped with grooves, they must be cleaned before each newmolding.9.3 Flow LengthFlow length shall be the farthest point atwhich the material completely fills the cross section of thehelix runner.10. Procedur

32、e10.1 Heat the mold and transfer the plunger to 423 6 3K(150 6 3C (302 6 5F).10.2 Plungers equipped with sealing grooves must becleaned free of compound before each molding.10.3 Using a force gage or proving ring, adjust the transferpressure to 6.90 6 0.17 MPa (1000 6 25 psi).10.4 Weigh out the comp

33、ound to the nearest 0.1 g aspreviously determined to yielda3to3.5-mm (0.12 to 0.14-in.)molded cull.10.5 Place the compound in the transfer pot and activate thetransfer cycle immediately. Cure the compound as recom-mended for easy removal.10.6 Open mold and remove the cured material. Read thespiral f

34、low length directly from the molded specimen at thepoint of farthest continuous flow to the nearest 0.25 in. (Note3).10.7 Repeat 10.4 to 10.6 until three consecutive flowreadings agree to within 65 % of their average.11. Report11.1 Report the following information:11.1.1 The accurate identity of the

35、 sample tested,11.1.2 Average spiral-flow length reported to the nearest6.35 mm (0.25 in.),11.1.3 The temperature and pressure used for the test,11.1.4 The form of the material (granulated, preformed,etc.),11.1.5 The average cull thickness and charge mass used, and11.1.6 The ram diameter and speed.1

36、2. Precision and Bias12.1 Statistical analysis of round-robin data4indicates thatwithin a given laboratory the averages of three flow lengthdeterminations on a typical material will not differ from eachother by more than 1.29 in. at a 95 % confidence level.Attempts to develop a full precision and bi

37、as statement for thistest method have not been successful. For this reason, data onprecision and bias cannot be given. Because this test methoddoes not contain a round-robin-based numerical precision andbias statement, it shall not be used as a referee test method incase of dispute. Anyone wishing t

38、o participate in the develop-ment of precision and bias data should contact the Chairman,Subcommittee D20.30 (Section 20.30.08), ASTMInternational, 100 Barr Harbor Drive, West Conshohocken, PA19428.13. Keywords13.1 spiral flow; thermosets4Round-robin data for this test method are available from ASTM

39、 Headquarters.Request RR:D20-1028.D3123 09 (2017)3ASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this standard. Users of this standard are expressly advised that determination of the validity of any such patent right

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