1、VU AMERICAN SOCIETY FOR TESTING AND MATERIALS 1916 Race St.,Philadelphia,Pa.19103 Reprinted from the Annual Book of ASTM Standards,Copyright ASTM If not listed in the current combined index,will appear in the next edition.Standard Practice for COMPRESSION MOLDING TEST SPECIMENS OF ALLYL.MOLDING COMP
2、OUNDS This standard is issued under the fixed designation D 3027;the number immediately following the desiktion indicates thc year o f original adoption or,in the case of revision.the year of last revision.A number in parentheses indicam the year of last rrappcoval.A superscrpt cpdon(e)indicates an
3、edditoral change ince the last revidon or reapprod.l.SCoDe erties obtained with different compounds,or be-tween different batches of the same compound.3.2 If the molded specimens show evidence of low density areas due to trapped gases,the spec-imens should be discarded.A breathe step should:be used
4、in molding new specimens.It is critical.to hold to a relatively brief breathe cycle to avoid procuring the granules before full pm is applied,Such a condition would result in poorly knitted areas and lower strength in the molded specimen.1.1 This practice covers the procedure to be used.for compress
5、ion molding the test specimens required for Specification D 1636.in SI units are to be regarded as standard.The values in parentheses are given for information only.1.3 This standard may involve hazardous ma-terials,operations,and equipmen.This sandard does not purport i o address all ofihe safetu p
6、rob-lems associaed with its use.It is the responsibil-1.2 The values iy o f the user o f this sandard to establish appro-priate safety and health practices and determine the applicability o f regulatory limiations prior to use.2.Referenced Documents 2.1 ASTM Standards:D647 Practice for Design of Mol
7、ds for Test Specimens of Plastic Molding Materials2 D958 Practice for Determining Temperatures of Standard ASTM Molds for Test Speci-mens of Plastic2 D 1636 Specification for Allyl Molding Compounds3 D2863 Test Method for Measuring the Mini-mum Oxygen Concentration to Support Candle-Like Combustion
8、of Plastics(Oxy-gen Index)3 3.Significance and Use 4.Apparatus 4.1-Molds(See Notes 1 and 2)4.1.1 Impact,Flexural,Flame Resistance,and Oxygen Index Specimens-Use the single bar,single cavity,positive mold shown in the figure illustrating the Single Bar,Single Cavity Positive Mold in Practice D647.The
9、 test specimens for the Test Method D2863 oxygen index t e s t shall be molded to a 3.2 mm(1 8.in.)thickness and cut to a 6.4 mm(Ih in.)width.4.1.2 Elecrical Test Specimens-Use the 10 I.6-mm(4-in.)di.ameter positive mold shown in the figure illustrating the Mold for Disk Test Specimens in Practice D
10、 647.NOTE I-The molds shown in Practice D47 are hand molds.For ease of molding,they may be made semi-automatic by bolting them to the press piatens.NOTE 2-Chrome plating of the cavities is recom-mended but not necessary.4.2 Press-The hydraulic press shall be such,3.1 The conditions under which sampl
11、es are molded influence the properties of the speci-mens.In determining whether a given compound meets the specification requirements,it is impor-is also necessary for a valid comparison of prop-I This practice is under the jurisdiction of ASTM Commitcc D-20 on Plda and is the dinct responsibitity o
12、f Subcommitta 20.09 on SNmen-tion.arrent dtion approved Au&28,1987.Published October 1987.originally publisbcd ar D3027-72.J-astprevousdtion D3027-72(1981Yt.tant to hold to a standard set of conditions.This i An,&o/Siandu,.&d a.01.Annual Book o f ASTM Standur&,Vol 08.02.I-*.1,NOTICE:This standard ha
13、s either been superseded and replaced by a new version or discontinued.Contact ASTM International(www.astm.org)for the latest information.,ASTM D3027 87 0759530 0028547 3 that molding pressure on the specimen can be maintained at the value,and within the toler-ances prescribed in Table 1.4.3 Heating
14、 System-Any convenient method of heating the press platens or molds may be used provided that the heat source is constant enough to maintain the mold tempera-ture prescribed in Table 1 with I T C (35F).4.4 Temperature Measurement:4.4.1 Mold Temperature-A 76.2-mm(3-in.)immersion,mercury-filled thermo
15、meter having a temperature scale of not more than 25C(45F)per 25.4 mm(1 in.)of lenm,or a surface-probe.pyrometer graduated at 2 C intervals.4.4.2 Preheat Temperature-A needle-probe pyrometer graduated at 2fC intervals.4.5 Preheater-Any electronic heating equip ment capable of.heating the sample quan
16、tity required for the specimen being molded.to the temperature,and within the time prescribed in Table 1.4.6 Oven-Any-circulating air oven capable of heating the sample quantity required for the.specimen being molded to the temperature,and within the time prescribed in Table 1.D 3027 5.Procedure 5.1 Mold the test specimens in accordance with conditions A,B,or C,as prescribed in Table 1.The preheated material of condition B or C should be transferred to the mold immediately after the preheating c