ASTM D3123-2009 Standard Test Method for Spiral Flow of Low-Pressure Thermosetting Molding Compounds《低压热固性模制化合物的螺线流的试验方法》.pdf

1、Designation: D 3123 09Standard Test Method forSpiral Flow of Low-Pressure Thermosetting MoldingCompounds1This standard is issued under the fixed designation D 3123; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last r

2、evision. 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 test method covers a procedure for measuring thespiral flow of thermosetting molding compounds (soft or verysoft) desi

3、gned 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 temperature and pressur

4、ewith 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 safety and health pr

5、actices and determine the applica-bility of regulatory limitations prior to use.NOTE 1There is no known ISO equivalent to this test method.2. Referenced Documents2.1 ASTM Standards:2D 883 Terminology Relating to PlasticsD 958 Practice for Determining Temperatures of StandardASTM Molds for Test Speci

6、mens of Plastics3E 105 Practice for Probability Sampling Of Materials3. Terminology3.1 Definitions Definitions in this test method are consis-tent with Terminology D 883.4. Significance and Use4.1 The spiral flow of a thermosetting molding compound isa measure of the combined characteristics of fusi

7、on 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 similar or different moldingcompounds because it c

8、annot 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 Transfer Molding Press with a minimum 150 by150-mm

9、(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 with at least one peripheral sealinggroove. It is r

10、ecommended 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, reason-able correlations may be achieved between laboratories using presses withdifferent pot diameters. Typical examples are pr

11、esses 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 pot diam-eters, even within this listed range, have caused large differences inflow-length readings. Therefore, for best interlaboratory corre

12、lation it isrecommended that identical pot diameters be used.5.2 Standard Spiral-Flow Mold shown in Fig. 1 shall beutilized.6. Materials6.1 Molding Compound:1This test method is under the jurisdiction of ASTM Committee D20 on Plasticsand is the direct responsibility of Subcommittee D20.30 on Thermal

13、 Properties(Section D20.30.08).Current edition approved Sept. 1, 2009. Published September 2009. Originallyapproved in 1972. Last previous edition approved in 2004 as D 3123 - 98(2004).2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceast

14、m.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.3Withdrawn.1*A Summary of Changes section appears at the end of this standard.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959

15、, United States.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 commercially available molds are calibrated ininches, spiral-flow length will be

16、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 over awider range of flow lengths, but this has not yet been confirmed byinterlab

17、oratory 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 by their use.7. Sampling7.1 Unless otherwise agreed upon between the seller and

18、purchaser, sampling shall be in accordance with PracticeE 105. Sampling, based on engineering principles, prior topackaging shall be considered an acceptable alternative.8. Conditioning8.1 ConditioningAll molding compounds shall be testedin “as-received” condition. For referee testing, all materials

19、hall 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” moisture contentand tests shall be made as soon as possible once the contain

20、erhas 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 agents or lubricants. Several prelimi-nary moldings shall be made with the materia

21、l 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 temperature of 423 6 3 K (150 63C (302 6 5F) shall be maintained on the mold an

22、d transferplunger. Measure the temperature in accordance with theprocedures described in Practice D 958 or by thermocouplesattached to the mold and plunger. The temperature shall beallowed to reach equilibrium by waiting at least 3 min betweenmoldings.9.2.2 Transfer PressureThe actual pressure appli

23、ed 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 notFIG. 1 Standard Spiral-Flow MoldD3123092sufficiently accurate for determining transfer pressure. There-fore, the force exerted by the plunger shall be measured bysome means such

24、 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 plunger area insquare metres (or square inches).9.2.3 Charge MassThe mass of the compo

25、und 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 amount of compound and the dimen-sions of the transfer pot is critical in obtaining m

26、eaningful,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 is suggested as the starting chargemass.9.2.4 Transfer Plunger SpeedThe transfer pl

27、unger 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 the plunger shall be no more than 5seconds. Too long a dwell time before transferring

28、 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 recommendations for cure when possible.9.2.6 Transfer Plunger GroovesIf the transfer pl

29、unger 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. Procedure10.1 Heat the mold and transfer the plunger to 423 6 3K(150 6 3C (302 6 5F).10.2 P

30、lungers 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 compound to the nearest 0.1 g aspreviously determined to yielda3to3.5-mm (0.12 to 0.14-

31、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 flow length directly from the molded specimen at thepoint of farthest continuous flo

32、w 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 sample tested,11.1.2 Average spiral-flow length reported to the nearest6.35 mm (0.

33、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.12. Precision and Bias12.1 Statistical analysis of round-robin data4indicates thatwi

34、thin 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 bias statement for thistest method have not been successful. For this reason, data on

35、precision 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 to participate in the develop-ment of precision and bias data should contact the Cha

36、irman,Subcommittee D20.30 (Section 20.30.08), ASTM Interna-tional, 100 Barr Harbor Drive, West Conshohocken, PA 19428.13. Keywords13.1 spiral flow; thermosets4Round-robin data for this test method are available from ASTM Headquarters.Request RR: D20-1028.D3123093SUMMARY OF CHANGESCommittee D20 has i

37、dentified the location of selected changes to this standard since the last issue,D 3123 - 98(2004), that may impact the use of this standard. (September 1, 2009)(1) Updated ISO equivalency statement.(2) Updated precision and bias section.(3) Removed non-mandatory language where appropriate.ASTM Inte

38、rnational 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 rights, and the riskof infringement of such rights, are entirely

39、 their own responsibility.This standard is subject to revision at any time by the responsible technical committee and must be reviewed every five years andif not revised, either reapproved or withdrawn. Your comments are invited either for revision of this standard or for additional standardsand sho

40、uld be addressed to ASTM International Headquarters. Your comments will receive careful consideration at a meeting of theresponsible technical committee, which you may attend. If you feel that your comments have not received a fair hearing you shouldmake your views known to the ASTM Committee on Sta

41、ndards, at the address shown below.This standard is copyrighted by ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959,United States. Individual reprints (single or multiple copies) of this standard may be obtained by contacting ASTM at the aboveaddress or at 610-832-9585 (phone), 610-832-9555 (fax), or serviceastm.org (e-mail); or through the ASTM website(www.astm.org).D3123094