1、Designation: D 6111 03Standard 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 (e) 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
3、 shapes 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 ite
4、mor 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
5、Plastic 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 t
6、o be regarded as thestandard.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
7、 prior to use.NOTE 1There is no similar or equivalent ISO standard.2. Referenced Documents2.1 ASTM Standards:D 618 Practice for Conditioning Plastics for Testing2D 883 Terminology Relating to Plastics2D 1622 Test Method for Apparent Density of Rigid CellularPlastics2D 1898 Practice for Sampling of P
8、lastics2D 5033 Guide for the Development of Standards Relating tothe Proper Use of Recycled Plastics3D 6108 Test Method for Compressive Properties of PlasticLumber and Shapes3E 1 Specification for ASTM Thermometers4E 12 Terminology Relating to Density and Specific Gravityof Solids, Liquids, and Gase
9、s5E 691 Practice for Conducting an Interlaboratory Study toDetermine the Precision of a Test Method63. 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 DiscussionSpecific gravity a
10、t 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 and dimensiona
11、l 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, and may be compo
12、sed 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.)3.1.4.1 Discussion
13、In 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 Plasticsand is the direc
14、t responsibility of Subcommittee D20.20 on Plastic Products (SectionD20.20.01).Current edition approved March 10, 2003. Published April 2003. Originallyapproved in 1997. Last previous edition approved in 1997 as D 6111 - 972Annual Book of ASTM Standards, Vol 08.01.3Annual Book of ASTM Standards, Vol
15、 08.03.4Annual Book of ASTM Standards, Vol 14.03.5Annual Book of ASTM Standards, Vol 15.05.6Annual Book of ASTM Standards, Vol 14.02.1*A Summary of Changes section appears at the end of this standard.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959,
16、United 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
17、= 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. Hence, this definition is based on weights in air.(Se
18、e Terminology E 12.)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 de
19、termined, 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 th
20、e average densityof a large item.5.2 Variations in density of a particular plastic lumber orshapes specimen may be due to changes in crystallinity, loss ofplasticizer/solvent content, differences in degree of foaming, orto other causes. Portions of a sample may differ in densitybecause of difference
21、 in 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 cross-sectional area of the specimen
22、 is required forfuture testing on a particular sample, it may be determinedfrom a specific gravity measurement, see Note 10 (Eq 5).6. Apparatus6.1 BalanceA balance large enough to accommodate thespecimen conveniently, with a precision within 1.0 mg, accu-racy within 0.05 % relative (that is 0.05 % o
23、f the weight of thespecimen in air), and equipped with a means of support for theimmersion cage.NOTE 3Assurance that the balance meets the performance require-ments should be provided by frequent checks on adjustments of zero pointand sensitivity and by periodic calibration for absolute accuracy, us
24、ingstandard masses.6.2 Immersion Cage:6.2.1 WireA corrosion-resistant wire for suspending thecage.6.2.2 CageA device 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 diagramme
25、d 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 the specimen,
26、 and should beeasily 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 above and below the standard tempera
27、ture, and having anice point for calibration. A thermometer short enough to behandled inside the balance case will be found convenient.ASTM Thermometer 23C (see Specification E 1) andAnschtz-type thermometers have been found satisfactory forthis purpose.7. Materials7.1 WaterThe water shall be distil
28、led, deionized, or dem-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 hollo
29、w, varying in material 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.FIG. 1 Typical Configuration of Test ApparatusD61110329. Test Specimens9.1 Test specimens for
30、determining the bulk specific gravityor bulk density of plastic lumber and shapes shall be cut fromthe “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. Car
31、e must be taken in cutting 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 4Expect for specified tolerances,
32、the specimen requirementsgiven in 9.1 and 9.2 above are the same for Test Method D 6108.Specimens prepared in accordance with Test Method D 6108 may,therefore, be used to determine bulk specific gravity or density prior tobeing subjected to the destructive compression tests.9.3 In such cases where t
33、he cross section is known orsuspected to be porous, hollow or contain voids, or both, thecut ends should be sealed to prevent the ingress of water fromproducing false results.NOTE 5Nominal 0.05 mm thick, unreinforced plastic packaging tapehas been found suitable for sealing the cut ends. Considering
34、 the weightof the tape compared to the weight of the specimen, as well as the relativedensity of the tape, use of this plastic tape to seal the cut ends will havea negligible effect on the final density and specific gravity calculations.Use of a different type of tape or an other method to seal the
35、cut ends may,however, require correction factors for accurate results.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 % r
36、elative humidity for not less than 40hours prior to test in accordance 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 stand
37、ardlaboratory 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 Weigh the specimen in air to the nearest 1.0 mg.Record this as a, the weight of the specimen in air.NOTE 6The specimen may be weighed i
38、n air after hanging from thewire. In this case, record the weight of the specimen, a = (weight ofspecimen + 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 i
39、mmersion cage to the wire such that it issuspended 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
40、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 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 re
41、commended.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 thenearest 1.0 mg. Record this weight as b (the weight of theimmersed specimen, wire, cage, and sinker). Unless otherwisespecified, weigh rapidly in o
42、rder to minimize absorption ofwater by the specimen.NOTE 7It may be necessary to change the sensitivity adjustment ofthe balance to overcome the damping effect 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 st
43、ep.Record this weight as w (weight of the wire, cage, and sinkerin liquid).NOTE 8It is convenient to mark the level of immersion by means ofa shallow notch filed in the wire. The finer the wire, the greater thetolerance which may be permitted in adjusting the level of immersionbetween weighing.NOTE
44、9If the wire and cage are left attached to the balance during aseries of determinations, the weight a may be determined either with theaid of a tare on the balance. In such cases, care must be taken that thechange of weight of the wire and cage (for example, from visible water)between readings does
45、not exceed the desired precision.11.7 Repeat the procedure for a minimum 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
46、 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 3 0.9976 (4)NOTE 10Bulk density i
47、n g/cm3may be converted to lb (mass)/ft3asfollows:g/cm33 62.43 5 lb/ft3(5)NOTE 11For right prismatic plastic lumber and shapes, the crosssectional area is often difficult to determine utilizing conventional mea-surement techniques. The specific gravity results may be used to calculatethe cross secti
48、onal area by calculating effective cross sectional area from:area, cm25 a1wb! / 0.9976 3 length, cm! (6)13. Report13.1 Report the following information:D611103313.1.1 Complete identification of the material or producttested, including type, source, manufacturers code number,form, principal dimension
49、s, and previous history,13.1.2 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
