1、Designation: D 5644 01Standard Test Methods forRubber Compounding MaterialsDetermination of ParticleSize Distribution of Recycled Vulcanizate ParticulateRubber1This standard is issued under the fixed designation D 5644; the number immediately following the designation indicates the year oforiginal a
2、doption or, in the case of revision, 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. Scope1.1 These test methods describe the procedures for deter-mining average
3、particle size distribution of recycled vulcani-zate particulate.1.2 Method A describes the Ro-tap sieve test method for 60mesh or coarser particles.1.3 Method B describes the ultrasonic technique combinedwith optical microscope especially suitable for 80 mesh or finerparticles. This procedure is bas
4、ed on Test Method D 3849.1.4 The values stated in SI units are to 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 prac
5、tices and determine the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:D 297 Test Methods for Rubber ProductsChemicalAnalysis2D 1416 Test Methods for Rubber from Synthetic SourcesChemical Analysis2D 1566 Terminology Relating to Rubber2D 3182 Practice
6、for Rubber-Materials, Equipment, and Pro-cedures for Mixing Standard Compounds and PreparingStandard Vulcanized Sheets2D 3191 Test Methods for Carbon Black in SBR (Styrene-Butadiene Rubber)Recipe and Evaluation Procedures2D 3192 Test Methods for Carbon Black Evaluation in NR(Natural Rubber)2D 3849 T
7、est Method for Carbon BlackPrimary AggregateDimensions from Electron Micorscope Image Analysis2D 5603 Classification for Rubber CompoundingMaterialsRecycled Vulcanizate Particulate Rubber2E 11 Specification for Wire-Cloth Sieves for Testing Pur-poses3E 105 Practice for Probability Sampling of Materi
8、als33. Terminology3.1 Definitions:3.1.1 parent compound, noriginal compound used in theproduct.3.1.2 recycled vulcanizate rubber, nvulcanized rubberthat has been processed to give particulates or other forms ofdifferent shapes, sizes, and size distributions.3.1.3 DiscussionThe words “vulcanizate” an
9、d “vulca-nized rubber” are interchangeable. Additional terminologyassociated with this classification can be found in TerminologyD 1566.4. Significance and Use4.1 The particulate size distribution of vulcanizate particu-late rubber is used for the purpose of assigning a product meshor average partic
10、le size designation.4.2 The product designation for mesh size for the Ro-tapmethod (Method A, as follows) is based on the size designationscreen which allows a range for the upper limit retained ofmaximum 5 % for up to 850 m (20 mesh) particles, maximum10 % for 600 to 150 m (30 to 100 mesh), and max
11、imum 15 %for 128 to 75 m (120 to 200 mesh). No rubber particles shallbe retained on the zero screen (see Table 1, ClassificationD 5603).4.3 For Method A, the weight percent retained on a specificscreen is noted whereas in Method B (ultrasonic technique),the number of particles at a particular size i
12、s counted.4.4 Method B addresses problems that may be caused bytackiness and static electrical forces that recycled rubberparticles exert on each other to form agglomerates, especiallyfor 80 mesh or finer particles. This method eliminates agglom-erate formation by ultrasonically dispersing the parti
13、cles.4.5 Both methods can be used as a quality control tool.5. Method A: The Ro-tap Method5.1 Summary of Test Method1This test method is under the jurisdiction of ASTM Committee D11 on Rubberand is the direct responsibility of Subcommittee D11.26 on Recycled Rubber.Current edition approved Nov. 10,
14、2001. Published January 2002. Originallypublished as D 5644 - 96. Last previous edition D 5644 - 96.2Annual Book of ASTM Standards, Vol 09.01. 3Annual Book of ASTM Standards, Vol 14.02.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
15、5.1.1 Method ARo-tap Method5.1.1.1 A 100 6 1 g specimen of the recycled rubber iscombined with a fixed amount of talc and placed on top of aseries of mesh sieves, with the coarsest sieve being on top andthe finest on the bottom. The specimen is placed in a Ro-tapshaker for 10 to 20 min, depending on
16、 the grade of the recycledrubber. The weight of the rubber retained on the individualsieves is then recorded and the mesh designation of the productdetermined.6. Apparatus6.1 Mechanical Sieve Shaker4This is a mechanicallyoperated sieve shaker that imparts a uniform rotary and tappingmotion to a stac
17、k of 200-mm (8-in.) sieves in accordance with6.2. The sieve shaker should be adjusted to accommodate astack of sieves, receiver pan, and cover plate. The bottom stopsshould be adjusted to give a clearance of 1.5 mm (0.06 in.)between the bottom plate and the screens so that the screenswill be free to
18、 rotate. The sieve shaker machine shall bepowered with an electric motor operating 28.75 to 29.17 Hz(1725 to 1750 rpm). This will produce 2.33 to 2.60 Hz and 280to 320 rotary motions/min. The cover plate shall be fitted witha cork stopper that shall extend from 3.00 to 9.00 mm (0.118to 0.354 in.) ab
19、ove the metal recess. At no time shall a rubber,wood, or other material other than cork be permitted.6.2 Standard Sieves, stainless steel or brass, 200 mm (7.9in.) in diameter in accordance with Specification E 11. Thesieve set should include a lid and a bottom pan.6.3 Balance, with a sensitivity of
20、 0.1 g.6.4 Brush.6.4.1 A Tyler Model 1778-SB soft brass wire brush forcleaning sieves 100 mesh and coarser.6.4.2 A nylon bristle brush for cleaning sieves finer than 100mesh.6.5 Jar, capacity of 500 cm3(1 pint) with large opening.6.6 Rubber Balls,5with a diameter from 25 to 50 mm (1 to2 in.) or Plas
21、tic Rings, with a height of 20 6 3 mm, an outsidediameter of 60 6 3 mm, and an inside diameter of 58 6 3 mm.The height of the balls or rings must be lesss than the depth ofthe screens being used. Enough balls or rings are needed tohave two balls or rings per sieve. Balls and rings are not to beused
22、simultaneously.6.7 Talcum Powders, usually some mixture of magnesiumsilicate, silica, magnesium oxide, magnesium-aluminum sili-cate with at least 90 % of the particles being less than 40 m(approximately 400 mesh) in size.7. Procedure7.1 Select test screens appropriate to the particle sizedistributio
23、n of the product being tested. A set of two to sixsieves and a receiver pan are normally used. The actual numberof sieves is to be agreed upon by vendor and customer.7.2 Clean each screen with brush (see 6.4), making sure allparticles are removed from both sides of screen.7.3 Stack test screens in o
24、rder of increasing mesh size withsmallest number on top (coarsest) and highest number onbottom (finest). For products of 425 m (40 mesh) or finer, addtwo rubber balls or plastic rings per sieve. For products coarserthan 425 m (40 mesh), the use of rubber balls or plastic ringsas agitation aid is opt
25、ional. Rubber balls and plastic rings arenot to be used simultaneously. Same size balls shall be used onany one screen.7.4 Add bottom receiver pan to stack.7.5 Obtain approximately 150 to 200 g of vulcanizateparticulate rubber from the lot (refer to Practice E 105).7.6 Prepare a 100-g specimen as fo
26、llows:7.6.1 Weigh 100 g of specimen to the nearest gram.7.6.2 Weigh talc according to product gradation designa-tion. For products designated coarser than 300 m (50 mesh),weigh 5.0 g of talc. For products designated 300 m (50 mesh)or finer, weigh 15.0 g of talc.7.6.3 Add talc to specimen.7.6.4 Mix t
27、horoughly by placing talc and specimen in a500-cm3(1-pt) jar and shake the jar for a minimum of 1 min,until agglomerates are broken and talc is uniformly mixed.7.7 Place the specimen on the top sieve and place a cover onthe stack.7.8 Place the stack in the shaker.7.9 Activate the shaker for 10 min f
28、or products designatedcoarser then 300 m (50 mesh). For products designated 300m (50 mesh) or finer, activate the shaker for 20 min.7.10 After the shaker completes the appropriate cycle,remove the stack.7.11 Starting with the top sieve, remove the screenedfraction by gently tapping its contents to o
29、ne side and pouringthe contents on the balance and recording its mass to thenearest 0.1 g. Record any mass less than 0.1 g as trace.7.12 Brush any material adhering to the bottom of thescreen onto the next finer screen.7.13 Zero the balance in preparation for weighing theretained contents of the nex
30、t screen.7.14 Repeat 7.11 to 7.12 until all sieves in the stack and thebottom pan have been emptied, weighed, and recorded. Thisgives percent retained on each screen.8. Calculation8.1 The sum of the masses of each fraction from the sievesand the bottom pan shall not be less than the original mass of
31、the specimen plus mass of talc less 2 g, or greater than theoriginal mass of the specimen plus 100 % of talc added. Repeattest if either of these conditions occurs.8.2 To adjust for the addition of talc to the specimen, themass of the contents of the bottom pan is adjusted by thefollowing equation:x
32、 5 y 2 z 2 100! (1)where:x = mass of rubber in bottom pan,y = total mass of contents in bottom pan, andz = total mass of contents of all six sieves plus bottom pan.8.3 The top screen (zero screen) selected shall be one inwhich no rubber particles are retained. This “zero percent4The Ro-Tap Sieve Sha
33、ker meets the specified conditions and has been foundsatisfactory for this purpose, and is available from many scientific laboratorysuppliers.5Available from various sieve manufacturing suppliers.D 56442retained screen” is designated in Classification D 5603 Table 1(see Note 1).8.4 The second screen
34、 in the sieve deck is for productdesignation and can contain a maximum 5 % rubber particlesfor up to 850 m (20 mesh) and a maximum 10 % for finer than850 m (20 mesh) (see Note 1).NOTE 1An example of 8.3 and 8.4 is if an 850-m (20 mesh) sievecontains zero rubber particles and a 600-m (30-mesh) sieve
35、contains 3 %rubber particles, then the proper product designation for this material is600-m (30-mesh) particulate rubber product.9. Report9.1 Report the following information:9.1.1 Date of test,9.1.2 Proper identification of specimens,9.1.3 Identification of each sieve used,9.1.4 The residue mass on
36、 each sieve,9.1.5 The mass on the bottom pan and its adjusted mass, and9.1.6 The product mesh size determined for the specimen.10. Precision and Bias10.1 Round-robin testing will be conducted and precisionand bias statements will be balloted for inclusion when testingis completed.11. Keywords11.1 pa
37、rticle size distribution; recycled vulcanizate particu-late rubber12. Method BUltrasonic and Light MicroscopyTechnique12.1 Summary of Test Method12.1.1 Method BUltrasonic Technique12.1.1.1 A 25 6 1 mg specimen of recycled rubber isultrasonically dispersed in acetone, diluted appropriately, andplaced
38、 on a microscope slide for subsequent light opticalmicroscopic analysis. Photomicrographs are taken of the speci-men and then computer software is used to automaticallydetermine area measurements of the particles. The area mea-surements are mathematically converted to diameter data,which then can be
39、 used to produce statistical data andhistograms of the particle size distribution.13. Apparatus13.1 Test tubes, 75 by 10 mm glass, with corks.13.2 A benchtop tank-type ultrasonic dispersion bath withan output of 40 to 80 KHz and 105 to 270 W power.13.3 Glass microscope slides,25by75mm.13.4 Transfer
40、pipettes, disposable polyethylene type.13.5 Light Optical Microscope, requirements for a micro-scope for this test are that it should have a transmitted lightaccessory, and also a port to attach a camera. The microscopeshould be capable of magnifications of 303.13.6 Image Analysis System, which coul
41、d consist of acamera, a video TV camera, or a digital camera system.13.6.1 If a film camera is used, a photograph scanner will beneeded to be able to scan the images and transfer them to acomputer for subsequent image analysis.13.6.2 If a video rate TV camera system is used, it must beconnected to a
42、 computer frame-grabber card that will enablethe user to directly transfer images to the computer forsubsequent image analysis.13.6.3 If a digital camera is used, the images can be directlycaptured and transferred to a computer.13.7 Computer, with adequate speed and memory to be ableto do image anal
43、ysis. This may vary depending on what camerasystem is used for the analysis.13.7.1 Computer software capable of dimensional imageanalysis.13.7.2 Computer program to determine statistics and histo-gram information.13.7.3 Stage micrometer.14. Reagents and Materials14.1 Acetone, commercial grade.14.2 R
44、ecycled rubber crumb.15. Sampling15.1 Put 100 6 1 g of the recycled rubber in a cappedcontainer and shake it ten times to ensure that the specimen iswell-mixed and the fine particles present have not settled,before testing.16. Test Procedures16.1 Place 25 6 1 mg of recycled rubber ina3mlglass testtu
45、be.16.2 Add 1 ml of acetone to the test tube and place a corkstopper in the test tube. At the same time, prepare another testtube with 1 ml of acetone only and put in a cork stopper.16.3 Sonicate the specimen at 105 to 270 W for 5 min 6 15s in an ultrasonic bath filled to 55 6 2 mm with the surfacta
46、ntsolution recommended by the manufacturer of the ultrasonicbath or use a suitable substitute solution. The test tube shouldnot be touching the bottom of the ultrasonic bath, but should besuspended in the bath by suspending a beaker. Many manufac-turers have available, as an option, a basket in whic
47、h a beakercan be suspended above the bottom of the bath.16.4 Dilute the specimen by transferring 1 to 6 drops of thesonicated solution to the other test tube containing 1 cm3ofacetone and sonicate for an additional 5 min.16.4.1 The number of drops used for the dilution depends onthe mesh grade of th
48、e specimen being analyzed and will varyfrom 1 drop for 170 mesh grades and finer up to 6 drops for thelarger particle size grades. The optimum number of drops forbest dispersion for each individual mesh grade must bedetermined by experimentation.16.4.2 After the final 5 min sonification, immediately
49、 place3 sequential drops on a clean glass microscope slide and allowthe solvent to evaporate. For some grades, it may be desirableto swirl the solvent on the microscope slide gently while thesolvent is evaporating to get an even distribution of theparticles on the slide.17. Specimen Analysis and Instrument Calibration17.1 Using transmitted light, analyze the particles at 303magnification and take photomicrographs of the specimens andalso a stage micrometer (see 13.7.3) at that exact magnifica-tion.17.2 Transfer the images into a computer by either scanningthe
