1、Designation: D5628 18Standard Test Method forImpact Resistance of Flat, Rigid Plastic Specimens byMeans of a Falling Dart (Tup or Falling Mass)1This standard is issued under the fixed designation D5628; the number immediately following the designation indicates the year oforiginal adoption or, in th
2、e case of revision, the 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. Scope*1.1 This test method covers the determination of the thresh-old value of impact-failure e
3、nergy required to crack or breakflat, rigid plastic specimens under various specified conditionsof impact of a free-falling dart (tup), based on testing manyspecimens.1.2 The values stated in SI units are to be regarded as thestandard. The values in parentheses are for information only.1.3 This stan
4、dard 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, health, and environmental practices and deter-mine the applicability of regulatory limitations prior to use.Specific haz
5、ard statements are given in Section 8.NOTE 1This test method and ISO 6603-1 are technically equivalentonly when the test conditions and specimen geometry required forGeometry FE and the Bruceton Staircase method of calculation are used.1.4 This international standard was developed in accor-dance wit
6、h internationally recognized principles on standard-ization established in the Decision 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
7、:2D618 Practice for Conditioning Plastics for TestingD883 Terminology Relating to PlasticsD1600 Terminology forAbbreviated Terms Relating to Plas-ticsD1709 Test Methods for Impact Resistance of Plastic Filmby the Free-Falling Dart MethodD2444 Practice for Determination of the Impact Resistanceof The
8、rmoplastic Pipe and Fittings by Means of a Tup(Falling Weight)D3763 Test Method for High Speed Puncture Properties ofPlastics Using Load and Displacement SensorsD4000 Classification System for Specifying Plastic Materi-alsD5947 Test Methods for Physical Dimensions of SolidPlastics SpecimensD6779 Cla
9、ssification System for and Basis of Specificationfor Polyamide Molding and Extrusion Materials (PA)E691 Practice for Conducting an Interlaboratory Study toDetermine the Precision of a Test Method2.2 ISO Standards:3ISO 291 Standard Atmospheres for Conditioning and Test-ingISO 6603-1 PlasticsDetermina
10、tion of Multiaxial ImpactBehavior of Rigid PlasticsPart 1: Falling Dart Method3. Terminology3.1 Definitions:3.1.1 For definitions of plastic terms used in this testmethod, see Terminologies D883 and D1600.3.2 Definitions of Terms Specific to This Standard:3.2.1 failure (of test specimen)the presence
11、 of any crackor split, created by the impact of the falling tup, that can beseen by the naked eye under normal laboratory lightingconditions.3.2.2 mean-failure energy (mean-impact resistance)theenergy required to produce 50 % failures, equal to the productof the constant drop height and the mean-fai
12、lure mass, or, tothe product of the constant mass and the mean-failure height.3.2.3 mean-failure height (impact-failure height)theheight at which a standard mass, when dropped on testspecimens, will cause 50 % failures.NOTE 2Cracks usually start at the surface opposite the one that isstruck. Occasio
13、nally incipient cracking in glass-reinforced products, forexample, is difficult to differentiate from the reinforcing fibers. In suchcases, a penetrating dye can confirm the onset of crack formation.1This test method is under the jurisdiction ofASTM Committee D20 on Plasticsand is the direct respons
14、ibility of Subcommittee D20.10 on Mechanical Properties.Current edition approved May 1, 2018. Published June 2018. Originallyapproved in 1994. Last previous edition approved in 2010 as D5628 - 10. DOI:10.1520/D5628-18.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact AS
15、TM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.3Available from American National Standards Institute (ANSI), 25 W. 43rd St.,4th Floor, New York, NY 10036, http:/www.ansi.org.*A Summary of Ch
16、anges section appears at the end of this standardCopyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United StatesThis international standard was developed in accordance with internationally recognized principles on standardization established in the D
17、ecision on Principles for theDevelopment of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.13.2.4 mean-failure mass (impact-failure mass)the mass ofthe dart (tup) that, when dropped on the test specimens from ast
18、andard height, will cause 50 % failures.3.2.5 tupa dart with a hemispherical nose. See 7.2 andFig. 1.4. Summary of Test Method4.1 A free-falling dart (tup) is allowed to strike a supportedspecimen directly. Either a dart having a fixed mass is droppedfrom various heights, or a dart having an adjusta
19、ble mass isdropped from a fixed height. (See Fig. 2).4.2 The procedure determines the energy (mass height)that will cause 50 % of the specimens tested to fail (meanfailure energy).4.3 The technique used to determine mean failure energy iscommonly called the Bruceton Staircase Method or the Up-and-Do
20、wn Method (1).4Testing is concentrated near the mean,reducing the number of specimens required to obtain a reason-ably precise estimate of the impact resistance.4.4 Each test method permits the use of different tup and testspecimen geometries to obtain different modes of failure,permit easier sampli
21、ng, or test limited amounts of material.There is no known means for correlating the results of testsmade by different impact methods or procedures.5. Significance and Use5.1 Plastics are viscoelastic and therefore are likely to besensitive to changes in velocity of the mass falling on theirsurfaces.
22、 However, the velocity of a free-falling object is afunction of the square root of the drop height. A change of afactor of two in the drop height will cause a change of only 1.4in velocity. Hagan et al (2) found that the mean-failure energyof sheeting was constant at drop heights between 0.30 and 1.
23、4m. This suggests that a constant mass-variable height methodwill give the same results as the constant height-variable masstechnique. On the other hand, different materials responddifferently to changes in the velocity of impact. While bothconstant-mass and constant-height techniques are permitted
24、bythese methods, the constant-height method is to be used forthose materials that are found to be rate-sensitive in the rangeof velocities encountered in falling-weight types of impacttests.5.2 The test geometry FA causes a moderate level of stressconcentration and can be used for most plastics.5.3
25、Geometry FB causes a greater stress concentration andresults in failure of tough or thick specimens that do not failwith Geometry FA (3). This approach can produce a punchshear failure on thick sheet. If that type of failure isundesirable, Geometry FC is to be used. Geometry FB issuitable for resear
26、ch and development because of the smallertest area required.5.3.1 The conical configuration of the 12.7-mm diametertup used in Geometry FB minimizes problems with tuppenetration and sticking in failed specimens of some ductilematerials.5.4 The test conditions of Geometry FC are the same asthose of T
27、est MethodAof Test Method D1709. They have beenused in specifications for extruded sheeting.Alimitation of thisgeometry is that considerable material is required.5.5 The test conditions of Geometry FD are the same as forTest Method D3763.5.6 The test conditions of Geometry FE are the same as forISO
28、6603-1.5.7 Because of the nature of impact testing, the selection ofa test method and tup must be somewhat arbitrary. Although achoice of tup geometries is available, knowledge of the final orintended end-use application shall be considered.5.8 Clamping of the test specimen will improve the preci-si
29、on of the data. Therefore, clamping is recommended.However, with rigid specimens, valid determinations can bemade without clamping. Unclamped specimens tend to exhibitgreater impact resistance.5.9 Before proceeding with this test method, reference thespecification of the material being tested. Table
30、 1 of Classifi-cation System D4000 lists the ASTM materials standards thatcurrently exist. Any test specimens preparation, conditioning,dimensions, or testing parameters or combination thereofcovered in the relevantASTM materials specification shall takeprecedence over those mentioned in this test m
31、ethod. If thereare no relevant ASTM material specifications, then the defaultconditions apply.6. Interferences6.1 Falling-mass-impact-test results are dependent on thegeometry of both the falling mass and the support. Thus,impact tests are used only to obtain relative rankings ofmaterials. Impact va
32、lues cannot be considered absolute unlessthe geometry of the test equipment and specimen conform tothe end-use requirement. Data obtained by different procedureswithin this test method, or with different geometries, cannot, ingeneral, be compared directly with each other. However, therelative rankin
33、g of materials is expected to be the samebetween two test methods if the mode of failure and the impactvelocities are the same.6.1.1 Falling-mass-impact types of tests are not suitable forpredicting the relative ranking of materials at impact velocitiesdiffering greatly from those imposed by these t
34、est methods.6.2 As cracks usually start at the surface opposite the onethat is struck, the results can be greatly influenced by thequality of the surface of test specimens. Therefore, the com-position of this surface layer, its smoothness or texture, levelsof and type of texture, and the degree of o
35、rientation introducedduring the formation of the specimen (such as during injectionmolding) are very important variables. Flaws in this surfacewill also affect results.6.3 Impact properties of plastic materials can be verysensitive to temperature. This test can be carried out at any4The boldface num
36、bers in parentheses refer to a list of references at the end ofthe text.D5628 182Dimensions of Conical Dart (Not to scale.)Fig. 1(b)NOTE 1Unless specified, the tolerance on all dimensions shall be 62%.Position Dimension, mm Dimension, in.A 27.2 1.07B 15 0.59C 12.2 0.48D 6.4 0.25E 25.4 1F 12.7 0.5R 6
37、.350.05 0.2500.002(nose radius)r (radius) 0.8 0.03S (diameter)A6.4 0.25 251 251ALarger diameter shafts shall be used.FIG. 1 Tup Geometries for Geometries FA (1a), FB (1b), FC (1c), FD (1d), and FE (1e)D5628 183reasonable temperature and humidity, thus representing actualuse environments. However, th
38、is test method is intendedprimarily for rating materials under specific impact conditions.7. Apparatus7.1 Testing MachineThe apparatus shall be constructedessentially as is shown in Fig. 2. The geometry of the specimenclamp and tup shall conform to the dimensions given in 7.1.1and 7.2.7.1.1 Specimen
39、 ClampFor flat specimens, a two-pieceannular specimen clamp constructed as shown in Fig. 3 isrecommended. For Geometries FAand FD, the inside diametershall be 76.0 6 3.0 mm (3.00 6 0.12 in.). For Geometry FB,the inside diameter shall be 38.1 6 0.80 mm (1.5 6 0.03 in.).For Geometry FC, the inside dia
40、meter shall be 127.0 6 2.5 mm(5.00 6 0.10 in.). For Geometry FE an annular specimen clampconstructed as shown in Fig. 4 is required. The inside diametershall be 40 6 2 mm (1.57 6 0.08 in.) (see Table 1). ForGeometries FA, FB, FC, and FD, the inside edge of the upperor supporting surface of the lower
41、 clamp shall be roundedslightly; a radius of 0.8 mm (0.03 in.) has been found to besatisfactory. For Geometry FE this radius shall be 1 mm (0.04in.).7.1.1.1 Contoured specimens shall be firmly held in a jig sothat the point of impact will be the same for each specimen.7.1.2 Tup Support, capable of s
42、upporting a 13.5-kg (30-lb)mass, with a release mechanism and a centering device toensure uniform, reproducible drops.NOTE 3Reproducible drops are ensured through the use of a tube orcage within which the tup falls. In this event, care should be exercised sothat any friction that develops will not r
43、educe the velocity of the tupappreciably.7.1.3 Positioning DeviceMeans shall be provided forpositioning the tup so that the distance from the impingingsurface of the tup head to the test specimen is as specified.7.2 Tup:7.2.1 The tup used in Geometry FA shall have a 15.86 60.10-mm (0.625 6 0.004-in.
44、) diameter hemispherical head oftool steel hardened to 54 HRC or harder.Asteel shaft about 13mm (0.5 in.) in diameter shall be attached to the center of theflat surface of the head with its longitudinal axis at 90 to thatsurface. The length of the shaft shall be great enough toaccommodate the maximu
45、m mass required (see Fig. 1(a) andTable 1).FIG. 2 One Type of Falling Mass Impact TesterD5628 1847.2.2 The tup used in Geometry FB shall be made of toolsteel hardened to 54 HRC or harder. The head shall have adiameter of 12.76 0.1 mm (0.500 6 0.003 in.) with a conical(50 included angle) configuratio
46、n such that the conical surfaceis tangent to the hemispherical nose. A 6.4-mm (0.25-in.)diameter shaft is satisfactory (see Fig. 1(b) and Table 1).7.2.3 The tup used for Geometry FC shall be made of toolsteel hardened to 54 HRC or harder. The hemispherical headshall have a diameter of 38.1 6 0.4 mm
47、(1.5 6 0.015 in.). Asteel shaft about 13 mm (0.5 in.) in diameter shall be attachedto the center of the flat surface of the head with its longitudinalaxis at 90 to that surface. The length of the shaft shall be greatenough to accommodate the maximum mass (see Fig. 1(c) andTable 1).7.2.4 The tup used
48、 in Geometry FD shall have a 12.70 60.25-mm (0.500 6 0.010-in.) diameter hemispherical head oftool steel hardened to 54 HRC or harder. A steel shaft about 8mm (0.31 in.) in diameter shall be attached to the center of theflat surface of the head with its longitudinal axis at 90 to thesurface. The len
49、gth of the shaft shall be great enough toaccommodate the maximum mass required (see Fig. 1(d) andTable 1).7.2.5 The tup used in Geometry FE shall have a 20.0 60.2-mm (0.787 6 0.008-in.) diameter hemispherical head oftool steel hardened to 54 HRC or harder.Asteel shaft about 13FIG. 3 Support Plate/Specimen/Clamp Configuration for Geometries FA, FB, FC, and FDFIG. 4 Test-Specimen Support for Geometry FETABLE 1 Tup and Support Ring DimensionsGeometryDimensions, mm (in.)Tup Diameter Inside Diameter Support RingFA 15.86 0.10 76.0 3.0(0.625 0.004) (3.0
