1、Designation: D5145 09 (Reapproved 2014)Standard Test Methods forNonvolatile and Pigment Content of Electrocoat Baths1This standard is issued under the fixed designation D5145; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the yea
2、r 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 the characterization of elec-trocoat baths through the determination of nonvolatile cont
3、entof inorganic pigment content.1.2 The values stated in SI units are to be regarded asstandard. No other units of measurement are included in thisstandard.1.3 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of the user of
4、 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:2D1193 Specification for Reagent WaterD2832 Guide for Determining Volatile and Nonvolatile Con-tent of Paint and Rela
5、ted CoatingsE180 Practice for Determining the Precision of ASTMMethods for Analysis and Testing of Industrial and Spe-cialty Chemicals (Withdrawn 2009)33. Summary of Test Method3.1 Two specimens are accurately weighed into aluminumweighing dishes. The dishes are placed in an oven at 110C for1 h, rew
6、eighed to obtain the nonvolatile matter content and, ifrequired, placed in a muffle furnace at 500C for2handweighed a third time to obtain the inorganic pigment content.4. Significance and Use4.1 The nonvolatile content and pigment content are mea-sures of total solids and inorganic pigment solids,
7、respectively,in electrocoat paints. In addition to production quality control,these properties are important in maintaining electrocoat bathsin the optimum range.4.2 Other test methods for determining nonvolatile contentof paint and paint related materials are described in GuideD2832.5. Apparatus5.1
8、 Analytical Balance with a sensitivity of 0.1 mg.5.2 Aluminum Weighing Dishes, 57 mm in diameter and 17mm deep. These commercial dishes may contain a lubricantused during their manufacture. This should be removed byheating the aluminum dishes on a hot plate at 300C untilvapors are no longer visible.
9、 Store the dishes in a desiccatoruntil needed.5.3 Syringes, 5-mL, disposable variety.5.4 Oven circulating, maintained at 110 6 2C.5.5 Muffle Furnace, maintained at 500 6 15C.6. Reagents6.1 Purity of WaterReferences to water shall be under-stood to mean water conforming to Type II of SpecificationD11
10、93.7. Sampling and Sample Preparation7.1 Obtain the sample while the electrocoat bath is underproper circulation so a uniform sample is obtained. In the caseof a ultrafiltrate sample, the material should be thoroughlymixed or stirred prior to drawing the sample, thereby ensuringuniformity.7.2 After
11、sampling, prior to removing the test specimen, it ismandatory the sample be shaken or stirred until it is homoge-neous and free of any settled material. This is particularlyimportant if there is a delay between sampling the bath andperforming this test procedure. The absence of settled materialshoul
12、d be ascertained visually or by inserting a spatula andscraping the bottom of the container. Continue to shake or stirthe sample until specimens are taken for measurement. ThisPoint is Very Important.1These test methods are under the jurisdiction of ASTM Committee D01 onPaint and Related Coatings, M
13、aterials, and Applications and are the directresponsibility of Subcommittee D01.21 on Chemical Analysis of Paints and PaintMaterials.Current edition approved July 1, 2014. Published July 2014. Originally approvedin 1990. Last previous edition approved in 2009 as D5145 09. DOI: 10.1520/D5145-09R14.2F
14、or referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.3The last approved version of this historical standard is refer
15、enced onwww.astm.org.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States1NONVOLATILE CONTENT8. Procedure8.1 Weigh two aluminum dishes separately, each to 0.1 mgand record as W1.8.2 Using a syringe, withdraw 1.0 to 1.5 mL of the wellmixed
16、sample, then quickly weigh the syringe to 0.1 mg,recording this weight as W2. Transfer the entire contents of thesyringe into the aluminum dish. Reweigh the empty syringe to0.1 mg and record as W3. In the case of ultrafiltrate clear liquidsor of low solids paints, increase the specimen size to 5 mL
17、andpreheat at 60C for 2 h. Duplicate this step with the secondaluminum dish (8.1).8.3 Add a few millilitres of water to the specimen in thealuminum dishes prior to placing them in the oven. Thisfacilitates uniform spreading of the material. Place the dishesin the 110C oven for 1 h.8.4 Remove the dis
18、hes from the oven and allow to cool toroom temperature in a desiccator. Reweigh them to 0.1 mg andrecord the weights as W4.8.5 Retain the dishes for measurement of inorganic pigmentcontent as detailed in a following section of these test methods.9. Calculation9.1 Calculate the percent nonvolatile co
19、ntent as follows:% NV 5W42 W1W22 W33100 (1)where:W1= weight of empty aluminum dish, g,W2= weight of syringe filled with sample, g,W3= weight of empty syringe, g, andW4= weight of dish and contents after1hat110C, g.10. Precision and Bias10.1 Precision is based on an interlaboratory study in whichthe
20、operators in each of ten laboratories analyzed in duplicateon 2 days, four different electrocoat-bath samples with non-volatile contents ranging from 0.30 to 25.2 %. The results wereanalyzed statistically in accordance with Practice E180. Theintralaboratory coefficient of variance was 1.6 % at 40 df
21、 andthe interlaboratory coefficient of variation was 2.3 % at 36 df.Based on these coefficients, the following criteria should beused for judging the acceptability of results at the 95 %confidence level.10.1.1 RepeatabilityTwo results, each the mean of dupli-cate determinations obtained by the same
22、operator on differentdays, should be considered suspect if they differ by more than4.6 % relative.10.1.2 ReproducibilityTwo results, each the mean of du-plicate determinations obtained by operators in differentlaboratories, should be considered suspect if they differ bymore than 6.7 % relative.10.2
23、Bias cannot be determined because there are no ac-cepted standards for nonvolatile content of electrocoat baths.INORGANIC PIGMENT CONTENT11. Procedure11.1 Place the weighing dishes used for the nonvolatilecontent determination in the muffle furnace at 500C for 2 h.11.2 After 2 h, remove the dishes f
24、rom the muffle furnace,transfer them to a desiccator and allow to cool to roomtemperature. After cooling, remove dishes and weigh to 0.1mg, recording these weights at W5.NOTE 1If an organic char is still present in the aluminum dish after 2h in the muffle furnace, continue heating in the furnace unt
25、il no char ispresent.12. Calculation12.1 Calculate the percent inorganic pigment as follows:% Inorganic Pigment EC Bath! 5W52 W1W22 W33100 (2)where:W1= weight of empty aluminum dish, g,W2= weight of syringe filled with sample, g,W3= weight of empty syringe, g, andW5= weight of aluminum dish and cont
26、ents after heating inmuffle furnace, g.13. Precision and Bias13.1 Precision estimates are based on an interlaboratorystudy in which the operators in ten different laboratoriesanalyzed in duplicate on 2 days, four electrocoat bath materialscontaining inorganic pigment content ranging from 0.17 to4.52
27、 weight %. The results were analyzed statistically inaccordance with Practice E180. The intralaboratory coefficientof variation was 2.2 % relative at 40 df and the interlaboratorycoefficient of variation was 10.8 % at 36 df. Based on thesecoefficients, the following criteria should be used for judgi
28、ngthe acceptability of results at the 95 % confidence level:13.1.1 RepeatabilityTwo results, each the mean of dupli-cate determinations, obtained by the same operator on differentdays, should be considered suspect if they differ by more than6.3 % relative.13.1.2 ReproducibilityTwo results, each the
29、mean of du-plicate determinations, obtained by operators in differentlaboratories, should be considered suspect if they differ bymore than 31.1 % relative.13.2 Bias cannot be determined because there are no ac-cepted standards for inorganic pigment content of electrocoatbaths.14. Keywords14.1 electr
30、ocoat bath; muffle furnace; nonvolatile content;pigment content; ultrafiltratesD5145 09 (2014)2ASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this standard. Users of this standard are expressly advised that determina
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