1、Designation: D6111 18Standard Test Method forBulk Density And Specific Gravity of Plastic Lumber andShapes by Displacement1This standard is issued under the fixed designation D6111; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, t
2、he 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 bulkdensity and specific gravity of plastic lumber and sh
3、apes 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 itemor
4、 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 Pla
5、stic 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 b
6、e 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, health, and environmental practices and deter-mine the applicability of regulatory li
7、mitations prior to use.NOTE 1There is no known ISO equivalent to this test method.1.6 This international standard was developed in accor-dance with internationally recognized principles on standard-ization established in the Decision on Principles for theDevelopment of International Standards, Guide
8、s and Recom-mendations issued by the World Trade Organization TechnicalBarriers to Trade (TBT) Committee.2. Referenced Documents2.1 ASTM Standards:2D618 Practice for Conditioning Plastics for TestingD883 Terminology Relating to PlasticsD1622 Test Method for Apparent Density of Rigid CellularPlastics
9、D1898 Practice for Sampling of Plastics (Withdrawn 1998)3D5033 Guide for Development ofASTM Standards Relatingto Recycling and Use of Recycled Plastics (Withdrawn2007)3D6108 Test Method for Compressive Properties of PlasticLumber and ShapesE1 Specification for ASTM Liquid-in-Glass ThermometersE12 Te
10、rminology Relating to Density and Specific Gravityof Solids, Liquids, and Gases (Withdrawn 1996)3E691 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 materialincluding voids in
11、herent in material as tested. (TerminologyD883)3.1.1.1 DiscussionSpecific gravity at 23/23C can beconverted to density 23C, g/cm3, as follows:D23C, g/cm35 sp gr 23/23C 30.9976 (1)3.1.2 plastic lumber, na manufactured product made pri-marily from plastic materials (filled or unfilled), typically used
12、as a building material for purposes similar to those of tradi-tional lumber, which is usually rectangular in cross-section.(Terminology D883)3.1.2.1 DiscussionPlastic lumber is typically supplied insizes similar to those of traditional lumber board, timber anddimension lumber; however the tolerances
13、 for plastic lumberand for traditional lumber are not necessarily the same.(Terminology D883)1This test method is under the jurisdiction of ASTM Committee D20 on Plasticsand is the direct responsibility of Subcommittee D20.20 on Plastic Lumber (SectionD20.20.01).Current edition approved June 1, 2018
14、. Published June 2018. Originallyapproved in 1997. Last previous edition approved in 2013 as D6111 - 13a. DOI:10.1520/D6111-18.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information
15、, refer to the standards Document Summary page onthe ASTM website.3The last approved version of this historical standard is referenced onwww.astm.org.*A Summary of Changes section appears at the end of this standardCopyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken,
16、PA 19428-2959. United StatesThis international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for theDevelopment of International Standards, Guides and Recommendations issued by the World Trade Organization
17、 Technical Barriers to Trade (TBT) Committee.13.1.3 plastic shape, na manufactured product made pri-marily from plastic materials (filled or unfilled), which is notnecessarily rectangular in cross section.3.1.4 resin, na solid or pseudosolid organic material oftenof high molecular weight, which exhi
18、bits a tendency to flowwhen subjected to stress, usually has a softening or meltingrange, and usually fractures conchoidally. (Terminology D883)3.1.4.1 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)t
19、he ratio of theweight in air of a unit volume of a permeable material(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
20、 be thefollowing:bulk specific gravity x/yC (2)where:x = temperature 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
21、. Hence, this definition is based on weights in air.(Terminology E12)3.2 Additional definition of terms applying to this testmethod appear in Terminology D883 and Guide D5033.4. Summary of Test Method4.1 Determine the weight of a specimen of the plasticlumber or shape in air. The specimen is then im
22、mersed inwater, its weight upon immersion is determined, 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 differen
23、tsampling units or specimens, or to indicate the average 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 cau
24、ses. It is possible thatportions of a sample will differ 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 D1622.5.3 Density is useful for calculating str
25、ength to weight andcost to weight ratios.5.4 If the cross-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 conven
26、iently, with a precision within 1.0 mg, accu-racy within 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, sen
27、sitivity,and absolute accuracy.6.2 Immersion Cage:6.2.1 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 cag
28、e diagrammed in Fig. 1.6.2.3 SinkerA sinker for use with 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 th
29、e specimen. It is important thatthe sinker be easily attached 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 abov
30、e and below the standard temperature, and having anice point for calibration.NOTE 3A thermometer short enough to be handled inside the balancecase will be found convenient. ASTM Thermometer 23C (see Specifica-tion E1) andAnschtz-type thermometers have been found satisfactory forthis purpose. Alterna
31、tive thermometers with equivalent or better accuracy,precision, and properties while covering the temperature range of 6.4 areacceptable.FIG. 1 Typical Configuration of Test ApparatusD61111827. Materials7.1 WaterThe water shall be distilled, deionized, or de-mineralized.8. Sampling8.1 The sampling u
32、nits used for the determination of spe-cific gravity shall be representative of the quantity of productfor which the data are required, in accordance with PracticeD1898.8.2 Plastic lumber and shapes are typically foamed, layeredor hollow, varying in material properties over the cross section.To esta
33、blish 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 shapes shall be cut fromthe “as manufacture
34、d” 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 cutting specimens toavoid changes in density resulting from compressive stresses orfrictional heati
35、ng.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 4Expect for specified tolerances, the specimen requirementsgiven in 9.1 and 9.2 above are the same for Test Method D6108.Itisacceptable, therefore, to u
36、se specimens prepared in accordance with TestMethod D6108 to determine bulk specific gravity or density prior to beingsubjected to the destructive compression tests.9.3 When the cross section of the material being tested isknown or suspected to be porous, hollow, or contain voids, orboth, seal the c
37、ut 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 the weight of the tape is small compared tothe weight of the specimens, use of the plastic tape wil
38、l 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 results.9.4 The specimen shall be free from oil, grease, and otherforeign matter.10. Conditioning10.1 C
39、onditioningUnless 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 accordance with Procedure A of PracticeD618. In cases of disagreement, the tolerances shall be 61Cand 62
40、% 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. In cases of disagreement, the tolerances shall be61C and 62 % relative humidity.11. Procedure11.1 W
41、eigh 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, record the weight ofthe specimen, a = (weight of specimen + wire + cage, in air) (weight of wire + ca
42、ge, 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 a marked distance above the base of the immersionvessel. Place the specimen in the cage, using sin
43、kers 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 adhering to the specimen, wire,cage, or sinker. Usually these bubbles can be removed byrubbing them wi
44、th 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 few drops of awetting agent shall be added.11.5 Determine the weight of the suspended specimen to
45、 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.11.5.1 For some materials, it will be necessary to change thesensitivity adjustment of the balanc
46、e 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 (weight of the wire, cage, and sinkerin liquid).11.6.1 It is acceptable to mark the level of immersio
47、n 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 thebalance during a series of determinations, determine the weighta with the aid of a tare on the ba
48、lance. 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 minimum of five specimensper sample.12. Calculation12.1 Calculate the bulk specific gravity of the sam
49、ple asfollows:Sp gr 23/23C 5 a/a1w 2 b! (3)D6111183where: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 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 30.9976 (4)12.2.1 The following formula is a means of converting bulkdensity in g/cm3to lb (mass)/ft3:g/cm3362.43 5 lb/ft3(5)12.2.2 For right pri
