ASTM D6111-2009 6875 Standard Test Method for Bulk Density and Specific Gravity of Plastic Lumber and Shapes by Displacement《对塑料层材和形材特殊重量和体密度的标准试验方法》.pdf

1、Designation: D 6111 09Standard Test Method forBulk Density And Specific Gravity of Plastic Lumber andShapes by Displacement1This standard is issued under the fixed designation D 6111; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision,

2、 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. Scope1.1 This test method covers the determination of the bulkdensity and specific gravity of plastic lumber and s

3、hapes intheir “as manufactured” form. As such, this is a test method forevaluating the properties of plastic lumber or shapes as aproduct and not a material property test method.1.2 This test method is suitable for determining the bulkspecific gravity or bulk density by immersion of the entire itemo

4、r a representative cross section in water. This test methodinvolves the weighing of a one piece specimen in water, usinga sinker with plastics that are lighter than water. This testmethod is suitable for products that are wet by, but otherwisenot affected by water for the duration of the test.1.3 Pl

5、astic lumber and plastic shapes are currently madepredominately from recycled plastics. However, this testmethod would also be applicable to similar manufacturedplastic products made from virgin resins where the product isnon-homogeneous in the cross-section.1.4 The values stated in SI units are to

6、be regarded asstandard.1.5 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 regulatory limitations prior

7、 to use.NOTE 1There is no known ISO equivalent to this test method.2. Referenced Documents2.1 ASTM Standards:2D 618 Practice for Conditioning Plastics for TestingD 883 Terminology Relating to PlasticsD 1622 Test Method for Apparent Density of Rigid CellularPlasticsD 1898 Practice for Sampling of Pla

8、stics3D 5033 Guide for Development of ASTM Standards Relat-ing to Recycling and Use of Recycled Plastics3D 6108 Test Method for Compressive Properties of PlasticLumber and ShapesE1 Specification for ASTM Liquid-in-Glass ThermometersE12 Terminology Relating to Density and Specific Gravityof Solids, L

9、iquids, and Gases3E 691 Practice for Conducting an Interlaboratory Study toDetermine the Precision of a Test Method3. Terminology3.1 Definitions:3.1.1 density, bulkthe weight per unit volume of a mate-rial including voids inherent in material as tested. (See Termi-nology D 883.)3.1.1.1 DiscussionSpe

10、cific gravity at 23/23C can beconverted to density 23C, g/cm3, as follows:D23C, g/cm35 sp gr 23/23C 3 0.9976 (1)3.1.2 plastic lumber, na manufactured product composedof more than 50 weight percent resin, and in which the productgenerally is rectangular in cross-section and typically suppliedin board

11、 and dimensional lumber sizes, may be filled orunfilled, and may be composed of single or multiple resinblends.3.1.3 plastic shape, na manufactured product composedof more than 50 weight percent resin, and in which the productgenerally is not rectangular in cross-section, may be filled orunfilled, a

12、nd may be composed of single or multiple resinblends.3.1.4 resin, na solid or pseudosolid organic material oftenof high molecular weight, which exhibits a tendency to flowwhen subjected to stress, usually has a softening or meltingrange, and usually fractures conchoidally. (See TerminologyD 883.)3.1

13、.4.1 DiscussionIn a broad sense, the term is used todesignate any polymer that is a basic material for plastics.3.1.5 specific gravity, bulk (of solids)the ratio of theweight in air of a unit volume of a permeable material1This test method is under the jurisdiction of ASTM Committee D20 on Plasticsa

14、nd is the direct responsibility of Subcommittee D20.20 on Plastic Products (SectionD20.20.01).Current edition approved Sept. 1, 2009. Published September 2009. Originallyapproved in 1997. Last previous edition approved in 2003 as D 6111 - 03.2For referenced ASTM standards, visit the ASTM website, ww

15、w.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.3Withdrawn.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United

16、States.(including both permeable and impermeable voids normal tothe material) at a stated temperature to the weight in air ofequal density of an equal volume of gas-free distilled water ata stated temperature. The form of expression shall be thefollowing:bulk specific gravity x/yC (2)where:x = tempe

17、rature of the material, andy = temperature of the water.3.1.5.1 DiscussionThe accuracy of bulk density determi-nations is so low that corrections for air buoyancy andvariations in the value for the acceleration of gravity are notwarranted. Hence, this definition is based on weights in air.(See Termi

18、nology E12.)3.2 Additional definition of terms applying to this testmethod appear in Terminology D 883 and Guide D 5033.4. Summary of Test Method4.1 Determine the weight of a specimen of the plasticlumber or shape in air. The specimen is then immersed inwater, its weight upon immersion is determined

19、, and its bulkspecific gravity calculated.5. Significance and Use5.1 The specific gravity or density of a solid is a propertythat can be measured conveniently to follow physical changesin a sample, to indicate degree of uniformity among differentsampling units or specimens, or to indicate the averag

20、e densityof a large item.5.2 It is possible that variations in density of a particularplastic lumber or shapes specimen will be due to changes incrystallinity, loss of plasticizer/solvent content, differences indegree of foaming, or to other causes. It is possible thatportions of a sample will diffe

21、r in density because of differencein crystallinity, thermal history, porosity, and composition(types or proportions of resin, plasticizer, pigment, or filler).NOTE 2Reference is made to Test Method D 1622.5.3 Density is useful for calculating strength to weight andcost to weight ratios.5.4 If the cr

22、oss-sectional area of the specimen is required forfuture testing on a particular sample, it is acceptable todetermine it from a specific gravity measurement, see Eq 5.6. Apparatus6.1 BalanceA balance large enough to accommodate thespecimen conveniently, with a precision within 1.0 mg, accu-racy with

23、in 0.05 % relative (that is 0.05 % of the weight of thespecimen in air), and equipped with a means of support for theimmersion cage.6.1.1 Calibrate the balance at least annually in accordancewith the manufacturers instructions for zero point, sensitivity,and absolute accuracy.6.2 Immersion Cage:6.2.

24、1 WireA corrosion-resistant wire for suspending thecage.6.2.2 CageAdevice large enough to support the bottom ofthe specimen and when weighted will transfer the sinker forceto the specimen to keep it from floating. Refer to the sampleimmersion cage diagrammed in Fig. 1.6.2.3 SinkerA sinker for use wi

25、th specimens of plasticsthat have specific gravities less than 1.000. The sinker shall: becorrosion-resistant; have a specific gravity of not less than 7.0;have smooth surfaces and a regular shape; and be slightlyheavier than necessary to sink the specimen. It is important thatthe sinker be easily a

26、ttached to the cage.6.3 Immersion VesselA beaker, bucket, or other wide-mouthed vessel for holding the water and immersed cage.6.4 ThermometerA thermometer having not fewer thanfour divisions per C over a temperature range of not less than5C above and below the standard temperature, and having anice

27、 point for calibration. A thermometer short enough to behandled inside the balance case will be found convenient.ASTM Thermometer 23C (see Specification E1) andAnschtz-type thermometers have been found satisfactory forthis purpose.7. Materials7.1 WaterThe water shall be distilled, deionized, or dem-

28、ineralized.8. Sampling8.1 The sampling units used for the determination of spe-cific gravity shall be representative of the quantity of productfor which the data are required, in accordance with PracticeD 1898.8.2 Plastic lumber and shapes are typically foamed, layeredor hollow, varying in material

29、properties over the cross section.To establish the overall specific gravity for a section, completeunmachined elements or representative cross sections of theseelements shall be used.9. Test Specimens9.1 Test specimens for determining the bulk specific gravityor bulk density of plastic lumber and sh

30、apes shall be cut fromFIG. 1 Typical Configuration of Test ApparatusD6111092the “as manufactured” profile. Plastic lumber is generallynon-uniform through the cross-section; no machining opera-tions other than those required to provide flat, parallel endsshall be conducted. Care must be taken in cutt

31、ing specimens toavoid changes in density resulting from compressive stresses orfrictional heating.9.2 The standard test specimen shall be in the form of a rightcylinder or prism where height is twice its minimum cross-section or diameter.NOTE 3Expect for specified tolerances, the specimen requiremen

32、tsgiven in 9.1 and 9.2 above are the same for Test Method D 6108.Itisacceptable, therefore, to use specimens prepared in accordance with TestMethod D 6108 to determine bulk specific gravity or density prior to beingsubjected to the destructive compression tests.9.3 When the cross section of the mate

33、rial being tested isknown or suspected to be porous, hollow, or contain voids, orboth, seal the cut ends to prevent ingress of water fromproducing false results.9.3.1 Unreinforced plastic packaging tape that is nominally0.05 mm in thickness has been found suitable for sealing thecut ends. Because th

34、e weight of the tape is small compared tothe weight of the specimens, use of the plastic tape will have anegligible effect on the final density and specific gravitycalculations. Use of a different type of tape or any othermethod to seal the cut ends will require correction factors foraccurate result

35、s.9.4 The specimen shall be free from oil, grease, and otherforeign matter.10. Conditioning10.1 ConditioningUnless otherwise specified by the cus-tomer or product specifications, condition the test specimens at23 6 2C and 50 6 5 % relative humidity for not less than 40hours prior to test in accordan

36、ce with Procedure A of PracticeD 618. In cases of disagreement, the tolerances shall be 61Cand 62 % relative humidity.10.2 Test ConditionsUnless otherwise specified by thecustomer or product specification, conduct tests in the standardlaboratory atmosphere of 23 6 2C and 50 6 5 % relativehumidity. I

37、n cases of disagreement, the tolerances shall be61C and 62 % relative humidity.11. Procedure11.1 Weigh the specimen in air to the nearest 1.0 mg.Record this as a, the weight of the specimen in air.11.1.1 It is acceptable to weigh the specimen in air afterhanging from the wire. When this is done, rec

38、ord the weight ofthe specimen, a = (weight of specimen + wire + cage, in air) (weight of wire + cage, in air).11.2 Attach to the balance a piece of fine wire sufficientlylong to reach from the balance to the base of the immersionvessel. Attach the immersion cage to the wire such that it issuspended

39、a marked distance above the base of the immersionvessel. Place the specimen in the cage, using sinkers if needed.11.3 Completely immerse the suspended specimen (andsinkers, if used) in water (see 7.1) at a temperature of 23 61C. The vessel must not touch wire or specimen.11.4 Remove any bubbles adhe

40、ring to the specimen, wire,cage, or sinker. Usually these bubbles can be removed byrubbing them with another wire. If the bubbles cannot beremoved by this method or if bubbles are continuously formed(as from dissolved gases), the use of vacuum is recommended.If the water does not wet the specimen, a

41、 few drops of awetting agent shall be added.11.5 Determine the weight of the suspended specimen to thenearest 1.0 mg. Record this weight as b (the weight of theimmersed specimen, wire, cage, and sinker). Unless otherwisespecified, weigh rapidly in order to minimize absorption ofwater by the specimen

42、.11.5.1 For some materials, it will be necessary to change thesensitivity adjustment of the balance to overcome the dampingeffect of the immersed specimen.11.6 Weigh the wire, cage, and sinker, if used, in water withimmersion to the same depth as used in the previous step.Record this weight as w (we

43、ight of the wire, cage, and sinkerin liquid).11.6.1 It is acceptable to mark the level of immersion bymeans of a shallow notch in the wire. The finer the wire, thegreater the tolerance permitted in adjusting the level ofimmersion between weighing.11.6.2 When the wire and cage are left attached to th

44、ebalance during a series of determinations, determine the weighta with the aid of a tare on the balance. When this done, takecare that the change in weight of the wire and cage (forexample, from visible water) between readings does not exceedthe desired precision.11.7 Repeat the procedure for a mini

45、mum of five specimensper sample.12. Calculation12.1 Calculate the bulk specific gravity of the sample asfollows:Sp gr 23/23C 5 a/ a 1 w b! (3)where:a = overall weight of specimen, without wire or sinker, inair,b = overall weight of specimen (and of cage and sinker)completely immersed and of the wire

46、 partially im-mersed in liquid, andw = overall weight of totally immersed sinker, cage, andpartially immersed wire.12.2 Calculate the bulk density of the sample as follows:D23C, g/cm35 Sp Gr 23/23C 3 0.9976 (4)12.2.1 The following formula is a means of converting bulkdensity in g/cm3to lb (mass)/ft3

47、:g/cm33 62.43 5 lb/ft3(5)12.2.2 For right prismatic plastic lumber and shapes, thecross sectional area is often difficult to determine utilizingconventional measurement techniques. The following formulais a means to use specific gravity results to calculate the crosssectional area, by calculating th

48、e effective cross sectional area:area, cm25 a1wb! / 0.9976 3 length, cm! (6)13. Report13.1 Report the following information:D611109313.1.1 Complete identification of the material or producttested, including type, source, manufacturers code number,form, principal dimensions, and previous history,13.1

49、.2 Laboratory name,13.1.3 Date of test,13.1.4 Method of specimen preparation and conditioning,13.1.5 Dimensions of the specimen as tested,13.1.6 Average overall specific gravity for all specimensfrom a sampling unit, reported as sp gr 23/23C = , oraverage density reported as D23C= g/cm3,13.1.7 A measure of the degree of variation of specificgravity or density within the sampling unit such as the standarddeviation and number of determinations,13.1.8 Any evidence of porosity of the specimen includingmaterial or method used to seal the cut ends