1、Designation: D4797 12Standard Test Methods forGravimetric Analysis of White and Yellow ThermoplasticTraffic Marking1This standard is issued under the fixed designation D4797; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year
2、 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 These test methods cover procedures for the gravimetricanalysis of the binder and hydrochloric Acid (HCL) insolubl
3、eparticles in white and yellow thermoplastic traffic markings.The HCL insoluble particles can be retroreflective optics, suchas glass beads or some other type of retroreflective optic, ornon-retroreflective particles such as silica sand, or a combina-tion of any two or more of these materials.1.2 Th
4、is standard does not address the physical separationand the individual quantification of each component when amixture of two or more HCL insoluble materials is present.Rather it requires the user to visually evaluate the HCLinsoluble material (obtained from following this test method)and report the
5、types of materials present.1.3 This standard does not purport to address the titaniumdioxide or lead chromate pigment measurement (after ashing)which is detailed in Test Methods D1394 and D126.1.4 This standard will attempt to address the interference oforganic pigments with the binder results.1.5 T
6、he analytical procedures appear in the following order:SectionsPercent Binder 10Percent Retroreflective Optics orNon-Retroreflective Particles111.6 The values stated in SI units are to be regarded as thestandard. The values given in parentheses are for informationonly.1.7 This standard does not purp
7、ort 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 to use.2. Referenced Documents2.1 ASTM Standards:2D12
8、6 Test Methods for Analysis of Yellow, Orange, andGreen Pigments Containing Lead Chromate and Chro-mium Oxide GreenD1394 Test Methods for Chemical Analysis of White Tita-nium PigmentsD7307 Practice for Sampling of Thermoplastic Traffic Mark-ing MaterialsD7308 Practice for Sample Preparation of Therm
9、oplasticTraffic Marking Materials3. Terminology3.1 Definitions of Terms Specific to This Standard:3.1.1 ash, nthe inorganic components of thermoplastictraffic marking including the pigment, glass spheres, and filler.3.1.2 binder, nthe organic components (resinous compo-nents) of thermoplastic traffi
10、c marking that bind the pigments,glass spheres, and filler together as a unit.3.1.3 filler, nthe inorganic components of thermoplastictraffic marking not including the pigments, retroreflectiveoptics, or non-retroreflective particles that are consideredfunctional.3.1.4 retroreflective optic, nfuncti
11、onal particle that reflectsand returns a relatively high proportion of light in a directionclose to the light source. This characteristic is maintained overa wide variation of the angle made by the incident light ray andnormal to the retroreflective surface. This includes a singlecomponent structure
12、 such as a spherical glass bead or a multicomponent structure with a core and a surface covered with asmall retroreflector.3.1.5 non-retroreflective particles, nfunctional particlethat is insoluble in HCL, such as aluminum oxide, groundglass, quartz, etc., that are added for skid resistance or other
13、non-retroreflective functional purpose.3.1.6 pigment, ntitanium dioxide, lead chromate colo-rants, and/or organic pigments.1These test methods are under the jurisdiction of ASTM Committee D01 onPaint and Related Coatings, Materials, and Applications and are the directresponsibility of Subcommittee D
14、01.44 on Traffic Coatings.Current edition approved June 1, 2012. Published August 2012. Originallyapproved in 1988. Last previous edition approved in 2007 as D4797 88 (2007).DOI: 10.1520/D4797-12.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at
15、 serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States13.1.7 thermoplastic, nSee thermoplastic traffc mark
16、ing.3.1.8 thermoplastic traffc marking, na highly filled100 % total solids highway marking system that when heatedto a molten state can be extruded or sprayed onto a road surfaceand when cooled forms a solid durable delineator.3.1.9 hydrochloric acid (HCL) insoluble particles,nretroreflective optics
17、, such as glass beads or some othertype of retroreflective optic, or non-retroreflective particlessuch as silica sand, or a combination of any two or more ofthese materials.4. Summary of Test Method4.1 Thermoplastic traffic marking material is prepared forthe described test methods by melting a samp
18、le to its applica-tion temperature under continuous agitation. The specimen isthen poured into round patties on a non-stick surface such as abaking pan. The patties are then broken into pieces for ignitionin a muffle furnace. The percent binder is calculated from theashed specimen and the various te
19、sts for retroreflective optics,non-retroreflective particles, titanium dioxide, and lead chro-mate pigment can be performed later on the ashed residue.Determining the binder content of organic pigment containingthermoplastic may not be as straight forward. Specimenselection and preparation are the s
20、ame for each sample tested.5. Significance and Use5.1 The function of these test methods is to define thepercent of binder and retroreflective optics or non-retroreflective particles in the composition of the thermoplastictraffic marking as defined by the applicable specification for themanufacture
21、of a specific thermoplastic traffic marking. Thesubsequent sample, as a result of ashing can be used to latertest for the presence of titanium dioxide, lead chromate andpossibly organic pigments.6. Apparatus6.1 Balance, analytical, accurate to 0.1 mg.6.2 Crucibles, 30+ mL, porcelain or aluminum pan.
22、6.3 Desiccator.6.4 Furnace (Muffle), capable of maintaining 540C(1004F).6.5 Hot Plate or Heating Mantle, capable of heating a can ofthermoplastic to 218C (425F).6.6 Sieve, 3 in., 45-m (No. 325) (metal).6.7 Buchner Funnel.6.8 Vacuum Flask and Rubber Hose.6.9 Vacuum Pump.6.10 Oven capable of reaching
23、218C (425F).6.11 Microwave Oven.6.12 400 mL Beaker or acid proof container.6.13 Magnetic Stirring Bar.6.14 Magnetic Stirring Plate.6.15 Spatula.7. Reagents7.1 Hydrochloric Acid Solution (HCL) (1 + 1 concentratedHCL diluted with equal volume of water).7.2 Hydrochloric Acid, Concentrated (HCL).8. Samp
24、ling8.1 Samples may be obtained in accordance with PracticeD7307 by an appropriate quartering or riffle sampling methodwhere deemed necessary considering the physical form of thematerial.9. Preparation of Specimens9.1 Melt a sample of thermoplastic traffic marking inaccordance with Test Method D7308
25、 to 218C (425F) (or permanufacturers recommended processing temperature) undercontinuous agitation on a hot plate or stir every 15 min in anoven set at 218C (425F) or per manufactures recommendedprocessing temperature.NOTE 1Road marking thermoplastic is manufactured in a wide varietyof viscosities a
26、t 218C. Some viscosities are so low that the retroreflectiveoptics settle quickly. In order to prevent any settlement during thesampling process, removing the test sample at a lower temperature iswarranted. Some thermoplastic test samples are best poured as low as160C (320F) as long as they can flow
27、 into patties.9.2 Flow the sample out on a smooth clean non-stick surfaceand allow it to cool to room temperature. Patties approximately3mm(18 in.) thick are usually easy to break up specimens forthe described analysis.9.3 Break the specimen into small pieces and weigh to thenearest 0.1 mg into a we
28、ighed crucible that is at least twice thevolume of specimen. The binder test can be done on samples assmall as 10 g (0.353 g) and be effective. Larger samples cansupply more retroreflective optics or non-retroreflective par-ticles for their evaluation later if required.9.4 Cover the crucible and pla
29、ce into a muffle furnacepreheated to 540C (1004F) and ash for 1 hour or until nocarbonaceous material remains.9.5 Remove the crucible with the ashed remains of thespecimen and place into a desiccator and cool to roomtemperature.10. Percent Binder10.1 InterferencesIf yellow organic-pigment-containing
30、road marking thermoplastic samples are ashed, the organicpigment may begin to degrade; therefore increasing the binderresults. If the theoretical amount of organic pigment content ofthe sample is known and assumption can be made as to whethersome or all the organic pigment has degraded (depending on
31、 itsdegradation temperature), then that amount can be accountedfor in the calculation in Eq 1.10.2 ProcedureWeigh the crucible and ash (see Section 9)to the nearest 0.1 mg and calculate the percent binder D asfollows:D 5 (12 (SW) 3 100 (1)D4797 122where:S = ashed weight of thermoplastic specimen, g,
32、 (crucible +ash wt.) crucible wt.W = weight of thermoplastic specimen, g, (crucible + ther-moplastic specimen) crucible wt.11. Percent Retroreflective Optics (RO) or Non-retroreflective Particles (NRP) using HydrochloricAcid (HCL)11.1 Procedure:11.1.1 Weigh the crucible and ash (see Section 9) to 0.
33、1 mgand calculate the percent ash.11.1.2 After the ashed material has been weighed, transferthe ash to a 400-mL beaker or other acid-proof container andwith minimal pressure, break apart the ashed specimen withoutcrushing the retroreflective optics.11.1.3 Add to the ash approximately 50 to 150 mL (1
34、.7 to 5oz.) of cold 1 + 1 HCL and stir occasionally until most of theeffervescence has ceased. (WarningThis is best performedunder a vented hood. Also, this procedure can be performedusing warmed HCL but is not necessary.)11.1.4 Immediately dilute the contents with as much wateras possible to allow
35、the RO or NRP to settle. Decant the waterand particulate carefully so as not to lose RO or NRP.11.1.5 If all the ash residue has not gone into solution,reintroduce HCL solution and stir. Continuous agitation canbest be achieved with a magnetic stirring bar and magneticstirrer. Stirring with a spatul
36、a can achieve similar results.11.1.6 Continue adding HCL or diluting with water anddecanting until the water is clear.11.1.7 Then transfer the residue into a weighed 3-in. 45-m(No. 325) sieve or a Buchner funnel containing a weighedcorrugated coffee filter and wash with enough cold water toremove an
37、y residue. If the RO or NRP do not appear clean, youshould repeat the acid washing process.11.1.8 Dry the sides and the bottom of the sieve with a papertowel and dry for 1 hour in a gravity oven preheated to 100C(212F). If using a Buchner funnel and coffee filters, a vacuumcan be pulled on the syste
38、m to evacuate the water and then theRO/NRP-containing-filters can be dried in a oven or micro-wave oven.11.1.9 Place the sieve or coffee filter in a desiccator and coolto room temperature.11.1.10 Weigh the sieve/filter and HCL insoluble particles(RO or NRP) to 0.1 mg and calculate the percent as fol
39、lows(see Note 2):NOTE 2Most road marking thermoplastic-ashed-residue which isinsoluble in HCL is a retroreflective optic.%HCL Insoluble Particles 5 R/W! 3100 (2)where:R = weight of residue after acid wash (g) (not includingsieve/filter wt.)W = original weight of thermoplastic specimen (g) (notinclud
40、ing crucible wt.)11.1.11 After completing the calculation examine thesample of acid insoluble particles obtained during the test todetermine the qualitative composition of the material. Includein the report the qualitative composition of the residue. Forexample, the HCL insoluble particles obtained
41、from this testare composed of 100 % retroreflective optics, or the HCLinsoluble particles obtained from this test are composed of bothretroreflective optics and non-retroreflective particles.12. Precision and Bias12.1 No general statement of precision can be made becauseof lack of sufficient data at
42、 this time.12.2 No statement of bias can be prepared for this testmethod since there is no absolute method for use as a basis forcomparison.13. Keywords13.1 binder; lead chromate; non-retroreflective particles;organic pigment; retroreflective optics; thermoplastic trafficmarking material; titanium d
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