1、Designation: D 2230 96 (Reapproved 2007)Standard Test Method forRubber PropertyExtrudability of UnvulcanizedCompounds1This standard is issued under the fixed designation D 2230; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the y
2、ear of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.1. Scope1.1 This test method covers the determination of the extrud-ability of unvulcanized SBR and NBR rubber compoundsth
3、rough a screw-type extruder equipped with ASTM ExtrusionDie, Garvey type. This test method is designed to allow theobservation of the appearance and contours of the extrusion.Rating systems are provided along with recipes for compoundsof known extrusion characteristics. The utility of the testmethod
4、 for evaluating rubbers or compounding materials otherthan those listed has not been established. Since extrusionmachines differ among laboratories, the procedure includestechniques that minimize differences between machines.1.2 The values stated in SI units are to be regarded as thestandard. The va
5、lues given in parentheses are for informationonly.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 practices and determine the applica-bility of r
6、egulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2D 3182 Practice for RubberMaterials, Equipment, andProcedures for Mixing Standard Compounds and Prepar-ing Standard Vulcanized SheetsD 3185 Test Methods for RubberEvaluation of SBR(Styrene-Butadiene Rubber) Including Mixtu
7、res With OilD 3187 Test Methods for RubberEvaluation of NBR(Acrylonitrile-Butadiene Rubber)2.2 ASTM Adjuncts:Appearance Ratings Photographs33. Summary of Test Method3.1 A standard compound is prepared and extruded througha specially shaped die that produces an extrusion having acombination of relati
8、vely flat surfaces, sharp corners, and thinsections. The operating conditions are varied until a satisfac-tory extrusion of the standard compound is obtained. The testcompound is then extruded, using the conditions just estab-lished, and the nature of the extrusion is rated visually forsmoothness, s
9、harp corners, and integrity of thin sections.4. Significance and Use4.1 One objective in the extrusion of rubber compounds isto obtain a smooth extrusion that closely reproduces thecontours of the extrusion die. This test method provides for asubjective determination of this under controlled conditi
10、ons.As the rating is subjective, it does not lend itself readily toincorporation as a specification requirement. It does not mea-sure other aspects of extrudability such as rate of extrusion ordie swell in a quantitative manner.5. Apparatus5.1 Mill, 150 by 300 mm (6 by 12 in.), as described inPracti
11、ce D 3182.5.2 DieASTM Extrusion Die, Garvey type, conforming tothe dimensions and shape shown in Fig. 1 shall be used.NOTE 1Good precision in the manufacture of the opening in the diecan be attained by ultrasonic machining. The die should be replaced whena dimension has changed by 0.02 mm (0.001 in.
12、) from its original valueor if the die is damaged.5.3 AdapterA hollow, cone-shaped ring insert taperedwith an angle of 30 6 15 (shown in Fig. 2) shall be used withthe die to contour the interior of the extruder head. This willreduce turbulent flow of the rubber.5.4 ExtruderA screw-type laboratory ex
13、truder having ascrew diameter of 50 mm or less and which will accommodatethe specified die may be used. The distance between the end ofthe screw and the die shall be from 1 to 2 times the diameterof the screw, the ratio of the length to diameter of the screwshall be 5:1 or greater, and the compressi
14、on ratio shall be 1:1.The use of breaker plates, screens, or spiders in the extruder is1This test method is under the jurisdiction of ASTM Committee D11 on Rubberand is the direct responsibility of Subcommittee D11.12 on Processability Tests.Current edition approved May 1, 2007. Published July 2007.
15、 Originally approvedin 1963. Last previous edition approved in 2002 as D 2230 96 (2002)e1.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Sum
16、mary page onthe ASTM website.3Glossy prints of Figs. 3 and 4 are available at a nominal cost from ASTMInternational Headquarters. Order Adjunct No. ADJD2230. Original adjunct pro-duced in 1986.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United
17、 States.not recommended. Solid or hollow screws are acceptable;however, fluid temperature shall be controlled in hollowscrews.5.4.1 The extruder shall be equipped with devices capableof monitoring the temperature of the barrel, the head, thedischarged heating fluid from the screw, and the surface of
18、 thedie. These monitoring devices shall have a sensitivity of60.5C (1F).5.5 Take-away ConveyerA motor-driven belt conveyor atleast 150 mm (6 in.) wide, at least 1.5 m (5 ft) long and variablein speed up to at least 75 mm/s (15 ft/min).5.6 Pyrometer or Equivalent Instruments, with a sensitivityof 60.
19、5C (1F) for measuring mill rolls and die surface.6. Materials: Standard Recipes6.1 The appropriate formulas and mixing procedures de-scribed in Test Methods D 3187 for NBR and Test MethodsD 3185 for SBR shall be used for preparing the standardDimension mm in. Dimension mm in.A 7.62 0.300 K 13.33 R 0
20、.525 RB 6.60 0.260 L 3.56 0.140C 4.44 0.175 M 3.301 R 0.130 RD 7.24 0.285 N 0.32 R 0.013 RE 7.62 0.300 O 20.32 R 0.800 RF 13.97 R 0.550 R P 0.25 R 0.010 RG 2.16 0.085 Q 3.56 0.140 RH 1.90 0.075 R 15.87 Dia 0.625 DiaI 3.05 0.120 S 0.13 0.005J 0.51 0.020 T 4.06 0.160Tolerance, 60.025 mm (60.001 in.)Ar
21、ea, 50 mm2(0.0776 in2)Thickness of die, 5 6 2.0 mm (0.197 6 0.79 in.)FIG. 1 ASTM Extrusion Die, Garvey TypeFIG. 2 Diagram Showing Stock Flow from End of Screw to ASTMExtrusion DieD 2230 96 (2007)2compound and test compound. The standard compound is usedto determine the proper combination of test con
22、ditions forevaluating the test compounds.6.2 The standard compound shall be mixed using the currentIndustry Reference Carbon Black (IRB) and either SBR 1500or NBR standard polymers as required. If a different compo-sition is to be evaluated, the reference and test compounds shallbe prepared by the s
23、ame recipe.NOTE 2If two batches must be blended to obtain sufficient materialfor a test, it is imperative that all mixes within a set receive equaltreatment, as extrusion characteristics change with milling or otherworking.7. Temperatures7.1 Mill Roll Temperature,506 5C (122 6 9F) shall beused for w
24、arm-up.7.2 Screw Fluid Temperature (if equipped for control), 4065C (104 6 9F).7.3 Barrel Temperature,706 10C (158 6 18F).7.4 Head Temperature,1106 15C (230 6 27F).7.5 Die Temperature,1106 15C (230 6 27F). The dietemperature may be allowed to reach equilibrium by conduc-tion or through application o
25、f external heat.7.6 The temperature ranges given in 7.2-7.5 are the rangeswithin which screw, barrel, head, and die temperatures may bevaried. The constancy of temperature, once set, should be62C.NOTE 3Certain rubbers may require temperatures for processing thatdo not fall within these limits. Indiv
26、idual adjustment must be made inthese cases.8. Procedure8.1 Weigh approximately 1 kg of standard compound andwarm up on the mill. The amount of stock required depends onthe size of the extruder. Set the mill rolls to form a rolling bank.Warm up the stock by banding it on the mill, and then cut theba
27、tch from side to side at 30-s intervals for 4 min. Record thestock temperature at the end of the warm-up operation.8.2 Set the rotational speed of the screw to 4.7 rad/s (45r/min). If the extrusion is not smooth, higher screw speeds maybe tried until a smooth delivery is obtained. Once the screwspee
28、d is established, it will remain unchanged during theevaluation of the samples being tested.8.3 Position the take-away conveyor so that the verticaldistance of the belt below the die opening does not exceed 25mm (1 in.) and the belt is centered below the extruder dieopening.8.4 Remove the die and re
29、move all stock from the die andextruder head. Replace the die and immediately proceed withthe following steps.8.5 Remove the stock from the mill in a continuous strip 3to 5 mm (0.12 to 0.20 in.) thick, adjusting the width to fit theflight width of the feed section of the screw. Feed the strip intoth
30、e extruder hopper until the barrel is full and the rubber beginsto extrude through the die. While continuing to feed theextruder, take the extrusion from the die by the take-awayconveyor. Avoid stretching the extrusion.8.6 By observation, determine when the extrusion hasreached a stable condition. M
31、easure the die temperature toensure that it has again stabilized at the set point. Select aspecimen approximately 250 mm (10 in.) in length that isrepresentative of the stable extrusion.8.7 Rate the extrusion by System A or B, described in 9.1and 9.2, respectively.8.8 If the rating for the standard
32、compound is not accept-able, adjust the extrusion temperatures within the prescribedlimitations in Section 7 and repeat the test on new batches ofthe standard compound until a rating of 4,4,4,4 by System A,or 10A by System B, is achieved. Once these conditions areestablished, do not change them duri
33、ng the evaluation of thetest compounds. If temperature changes are not successful,then try higher screw speeds as described in 8.2.8.9 Warm up the sample mix as described in 8.1 and repeat8.4-8.7 for the test or experimental rubber compounds, usingthe extrusion conditions established in 8.8.8.10 If
34、specimens are to be saved for reference purposes,rest them for 1 h with ends secured and then cure in open steamwith ends secured.9. Rating Systems9.1 System AThis system is based on four separate grad-ings, each grading represented by a digit. The first digit in therating refers to swelling or poro
35、sity, the second digit refers tosharpness and continuity of the 30 edge, the third digit refersto smoothness of the surface, and the fourth digit refers tosharpness and continuity of corners. The ratings range from 1(poor) to 4 (excellent) (see Fig. 3).39.2 System BIn this system, a combination of a
36、 digit anda letter of the alphabet is used to grade extrusions. The number,ranging from 1 (poor) to 10 (excellent), rates the sharpness andcontinuity of the 30 edge; the letter, ranging from A (excel-lent) to E (poor), rates the smoothness of the surface (see Fig.4).310. Report10.1 Report the follow
37、ing information:10.1.1 Stock identification.10.1.2 Extrusion conditions as follows:10.1.2.1 Stock temperature at end of warm-up,10.1.2.2 Screw temperature,10.1.2.3 Barrel temperature,10.1.2.4 Head temperature,10.1.2.5 Die temperature, and10.1.2.6 Screw rotational speed, (or angular speed), rad/s(r/m
38、in).10.1.3 Rating of the extrusion by either System A or SystemB, or both.11. Precision and Bias11.1 A precision statement is not directly applicable sinceboth Systems A and B yield only qualitative comparison datafor a candidate test compound versus a standard compound.11.2 Since no accepted refere
39、nce values can be determinedor theoretically calculated, no estimation of bias can be made.12. Keywords12.1 appearance; extrudability; extrusion; processabilityD 2230 96 (2007)3ASTM International takes no position respecting the validity of any patent rights asserted in connection with any item ment
40、ionedin 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 their own responsibility.This standard is subject to revision at any time by the responsible technical committee
41、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 should be addressed to ASTM International Headquarters. Your comments will receive careful consideration at a meeting
42、 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 Standards, at the address shown below.This standard is copyrighted by ASTM International, 100 Barr Harbor Drive, PO B
43、ox 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).FIG. 3 Appearance Ratings by Rating System AFIG. 4 Appearance Ratings by Rating System BD 2230 96 (2007)4
