1、Designation: D4797 12 D4797 12aStandard 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
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 These test methods cover procedures for the gravimetric analysis of the binder and hydrochloric Acid (HC
3、L) insolubleparticles in white and yellow thermoplastic traffic markings. The HCL insoluble particles can be retroreflective optics, such as glassbeads or some other type of retroreflective optic, or non-retroreflective particles such as silica sand, or a combination of any twoor more of these mater
4、ials.1.2 This standard does not address the physical separation and the individual quantification of each component when a mixtureof two or more HCL insoluble materials is present. Rather it requires the user to visually evaluate the HCL insoluble material(obtained from following this test method) a
5、nd report the types of materials present.1.3 This standard does not purport to address the titanium dioxide or lead chromate pigment measurement (after ashing) whichis detailed in Test Methods D1394 and D126.1.4 This standard will attempt to address the interference of organic pigments with the bind
6、er results.1.5 The 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 the standard. The values given in parentheses are for information only.1.7 This stan
7、dard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibilityof the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatorylimitations prior to use.2. Referenced Documents2.1 AST
8、M Standards:2D126 Test Methods for Analysis of Yellow, Orange, and Green Pigments Containing Lead Chromate and Chromium OxideGreenD1394 Test Methods for Chemical Analysis of White Titanium PigmentsD7307 Practice for Sampling of Thermoplastic Traffic Marking MaterialsD7308 Practice for Sample Prepara
9、tion of Thermoplastic Traffic Marking MaterialsE177 Practice for Use of the Terms Precision and Bias in ASTM Test MethodsE691 Practice for Conducting an Interlaboratory Study to Determine the Precision of a Test Method3. Terminology3.1 Definitions of Terms Specific to This Standard:3.1.1 ash, nthe i
10、norganic components of thermoplastic traffic marking including the pigment, glass spheres, and filler.1 These test methods are under the jurisdiction of ASTM Committee D01 on Paint and Related Coatings, Materials, and Applications and are the direct responsibility ofSubcommittee D01.44 on Traffic Co
11、atings.Current edition approved June 1, 2012Nov. 1, 2012. Published August 2012December 2012. Originally approved in 1988. Last previous edition approved in 20072012as D4797D4797 12. 88 (2007). DOI: 10.1520/D4797-12.10.1520/D4797-12A.2 For referenced ASTM standards, visit the ASTM website, www.astm.
12、org, or contact ASTM Customer Service at serviceastm.org. For Annual Book of ASTM Standardsvolume information, refer to the standards Document Summary page on the ASTM website.This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what cha
13、nges have been made to the previous version. Becauseit may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current versionof the standard as published by ASTM is to be considered the offi
14、cial document.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States13.1.2 binder, nthe organic components (resinous components) of thermoplastic traffic marking that bind the pigments, glassspheres, and filler together as a unit.3.1.3 fille
15、r, nthe inorganic components of thermoplastic traffic marking not including the pigments, retroreflective optics, ornon-retroreflective particles that are considered functional.3.1.4 retroreflective optic, nfunctional particle that reflects and returns a relatively high proportion of light in a dire
16、ction closeto the light source. This characteristic is maintained over a wide variation of the angle made by the incident light ray and normalto the retroreflective surface. This includes a single component structure such as a spherical glass bead or a multi componentstructure with a core and a surf
17、ace covered with a small retroreflector.3.1.5 non-retroreflective particles, nfunctional particle that is insoluble in HCL, such as aluminum oxide, ground glass,quartz, etc., that are added for skid resistance or other non-retroreflective functional purpose.3.1.6 pigment, ntitanium dioxide, lead chr
18、omate colorants, and/or organic pigments.3.1.7 thermoplastic, nSee thermoplastic traffc marking.3.1.8 thermoplastic traffc marking, na highly filled 100 % total solids highway marking system that when heated to a moltenstate can be extruded or sprayed onto a road surface and when cooled forms a soli
19、d durable delineator.3.1.9 hydrochloric acid (HCL) insoluble particles, nretroreflective optics, such as glass beads or some other type ofretroreflective optic, or non-retroreflective particles such as silica sand, or a combination of any two or more of these materials.4. Summary of Test Method4.1 T
20、hermoplastic traffic marking material is prepared for the described test methods by melting a sample to its applicationtemperature under continuous agitation. The specimen is then poured into round patties on a non-stick surface such as a bakingpan. The patties are then broken into pieces for igniti
21、on in a muffle furnace. The percent binder is calculated from the ashedspecimen and the various tests for retroreflective optics, non-retroreflective particles, titanium dioxide, and lead chromate pigmentcan be performed later on the ashed residue. Determining the binder content of organic pigment c
22、ontaining thermoplastic may notbe as straight forward. Specimen selection and preparation are the same for each sample tested.5. Significance and Use5.1 The function of these test methods is to define the percent of binder and retroreflective optics or non-retroreflective particlesin the composition
23、 of the thermoplastic traffic marking as defined by the applicable specification for the manufacture of a specificthermoplastic traffic marking. The subsequent sample, as a result of ashing can be used to later test for the presence of titaniumdioxide, lead chromate and possibly organic pigments.6.
24、Apparatus6.1 Balance, analytical, accurate capable of weighing to 0.1 mg.6.2 Crucibles, 30+ mL, porcelain or aluminum pan.6.3 Desiccator.6.4 Furnace (Muffle), capable of maintaining 540C (1004F).6.5 Hot Plate or Heating Mantle, capable of heating a can of thermoplastic to 218C (425F).6.6 Sieve, 3 in
25、., 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 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
26、 Solution (HCL) (1 + 1 concentrated HCL diluted with equal volume of water).7.2 Hydrochloric Acid, Concentrated (HCL).D4797 12a28. Sampling8.1 Samples may be obtained in accordance with Practice D7307 by an appropriate quartering or riffle sampling method wheredeemed necessary considering the physic
27、al form of the material.9. Preparation of Specimens9.1 Melt a sample of thermoplastic traffic marking in accordance with Test Method D7308 to 218C (425F) (or permanufacturers recommended processing temperature) under continuous agitation on a hot plate or stir every 15 min in an oven setat 218C (425
28、F) or per manufactures recommended processing temperature.NOTE 1Road marking thermoplastic is manufactured in a wide variety of viscosities at 218C. Some viscosities are so low that the retroreflectiveoptics settle quickly. In order to prevent any settlement during the sampling process, removing the
29、 test sample at a lower temperature is warranted. Somethermoplastic test samples are best poured as low as 160C (320F) as long as they can flow into patties.9.2 Flow the sample out on a smooth clean non-stick surface and allow it to cool to room temperature. Patties approximately3 mm (18 in.) thick
30、are usually easy to break up specimens for the described analysis.9.3 Break the specimen into small pieces and weigh to the nearest 0.1 mg into a weighed crucible that is at least twice thevolume of specimen. The binder test can be done on samples as small as 10 g (0.353 g) and be effective. Larger
31、samples can supplymore retroreflective optics or non-retroreflective particles for their evaluation later if required.9.4 Cover the crucible and place into a muffle furnace preheated to 540C (1004F) and ash for 1 hour or until no carbonaceousmaterial remains.9.5 Remove the crucible with the ashed re
32、mains of the specimen and place into a desiccator and cool to room temperature.10. Percent Binder10.1 InterferencesIf yellow organic-pigment-containing road marking thermoplastic samples are ashed, the organic pigmentmay begin to degrade; therefore increasing the binder results. If the theoretical a
33、mount of organic pigment content of the sampleis known and assumption can be made as to whether some or all the organic pigment has degraded (depending on its degradationtemperature), then that amount can be accounted for in the calculation in Eq 1.10.2 ProcedureWeigh the crucible and ash (see Secti
34、on 9) to the nearest 0.1 mg and calculate the percent binder D as follows:D 5 (12 (SW) 3 100 (1)D4797 12a3where:where:S = ashed weight of thermoplastic specimen, g, (crucible + ash wt.) crucible wt.W = weight of thermoplastic specimen, g, (crucible + thermoplastic specimen) crucible wt.11. Percent R
35、etroreflective Optics (RO) or Non-retroreflective Particles (NRP) using Hydrochloric Acid (HCL)11.1 Procedure:11.1.1 Weigh the crucible and ash (see Section 9) to 0.1 mg and calculate the percent ash.11.1.2 After the ashed material has been weighed, transfer the ash to a 400-mL beaker or other acid-
36、proof container and withminimal pressure, break apart the ashed specimen without crushing the retroreflective optics.11.1.3 Add to the ash approximately 50 to 150 mL (1.7 to 5 oz.) of cold 1 + 1 HCL and stir occasionally until most of theeffervescence has ceased. (WarningThis is best performed under
37、 a vented hood. Also, this procedure can be performed usingwarmed HCL but is not necessary.)11.1.4 Immediately dilute the contents with as much water as possible to allow the RO or NRP to settle. Decant the water andparticulate carefully so as not to lose RO or NRP.11.1.5 If all the ash residue has
38、not gone into solution, reintroduce HCL solution and stir. Continuous agitation can best beachieved with a magnetic stirring bar and magnetic stirrer. Stirring with a spatula can achieve similar results.11.1.6 Continue adding HCL or diluting with water and decanting until the water is clear.11.1.7 T
39、hen 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 to remove any residue. If the RO or NRP do not appear clean, you shouldrepeat the acid washing process.11.1.8 Dry the sides and the bott
40、om of the sieve with a paper towel and dry for 1 hour in a gravity oven preheated to 100C(212F). If using a Buchner funnel and coffee filters, a vacuum can be pulled on the system to evacuate the water and then theRO/NRP-containing-filters can be dried in a oven or microwave oven.11.1.9 Place the si
41、eve or coffee filter in a desiccator and cool to 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 follows (see Note2):NOTE 2Most road marking thermoplastic-ashed-residue which is insoluble in HCL is a retroreflective optic
42、.%HCL Insoluble Particles 5R/W!3100 (2)where:where:R = weight of residue after acid wash (g) (not including sieve/filter wt.)W = original weight of thermoplastic specimen (g) (not including crucible wt.)11.1.11 After completing the calculation examine the sample of acid insoluble particles obtained
43、during the test to determinethe qualitative composition of the material. Include in the report the qualitative composition of the residue. For example, the HCLinsoluble particles obtained from this test are composed of 100 % retroreflective optics, or the HCL insoluble particles obtainedfrom this te
44、st are composed of both retroreflective optics and non-retroreflective particles.12. Precision and Bias312.1 No general statement of precision can be made because of lackThe precision of this test method is based on aninterlaboratory study of ASTM D4797of sufficient data at this time.12, Standard Te
45、st Methods for Gravimetric Analysis of Whiteand Yellow Thermoplastic Traffic Marking, conducted in 2012. Seven laboratories participated in the study, testing four differentthermoplastic materials. Every analyst was instructed to report four replicate test results in this study. Practice E691 was fo
46、llowedfor the study design; the details are given in ASTM Research Report No. RR:D01-1166.12.1.1 Repeatability Limit (r)Two test results obtained within one laboratory shall be judged not equivalent if they differ bymore than the “r” value for that material; “r” is the interval representing the crit
47、ical difference between two test results for the samepaint, obtained by the same operator using the same equipment on the same day in the same laboratory.12.1.1.1 Repeatability limits are listed in Table 1 and Table 2.12.1.2 Reproducibility Limit (R)Two test results shall be judged not equivalent if
48、 they differ by more than the “R” value forthat material; “R” is the interval representing the critical difference between two test results for the same paint, obtained by differentoperators using different equipment in different laboratories.12.1.2.1 Reproducibility limits are listed in Table 1 and
49、 Table 2.12.1.3 The above terms (repeatability limit and reproducibility limit) are used as specified in Practice E177.3 Supporting data have been filed at ASTM International Headquarters and may be obtained by requesting Research Report RR:D01-1166.D4797 12a412.1.4 Any judgment in accordance with statements 12.1.1 and 12.1.2 would have an approximate 95 % probability of beingcorrect.12.2 BiasNo statement of bias can be prepared At the time of the study, there was no accepted reference material suitable fordetermining the bias f
