1、Designation: D 3925 02Standard Practice forSampling Liquid Paints and Related Pigmented Coatings1This standard is issued under the fixed designation D 3925; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision.
2、 A number in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.This standard has been approved for use by agencies of the Department of Defense.1. Scope1.1 This practice describes methods of taking represen
3、tativesamples of fluid paint or pigmented coating products fromcontainers of any type.1.2 Two ISO standards, ISO 1513 and ISO 15528, cover thedetails and equipment for sampling of liquid paints andassociated materials in much greater detail than this standard.The reader is referred to those standard
4、s for more information1.3 The sampling of dry powder paints, clear coatings,mixed solvents, and nonpigmented materials of any type is notcovered in this procedure.1.4 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of the
5、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:D 1475 Test Method for Density of Liquid Coatings, Inks,and Related Products22.2 ISO Documents:ISO 1513 Paints
6、 and varnishesExamination and prepara-tion of samples for testing3ISO 15528 Paints, varnishes and raw materials for paintsand varnishesSampling33. Terminology3.1 Definitions of Term Specific to This Standard:3.1.1 batchthe quantity of liquid paint or coating pro-duced in the final mixing operation a
7、fter all productionprocesses are complete. For example, when a number ofpigment dispersions are reduced with additional vehicle to-gether in a large tank, the resulting final mixture is one batch.4. Significance and Use4.1 Samples are taken from batches, lots, and shipments ofpaint in order to deter
8、mine their uniformity and compliancewith specification requirements. It is very important that thesesamples be of convenient and economical size and that they berepresentative of the batch of paint at the time it was filled intoshipping or storage containers.4.2 The time and effort necessary to ensu
9、re that the sampleis representative of the original material will be repaid inreduction of laboratory work and elimination of possiblerejections of acceptable material.5. Sampling Considerations5.1 The use of common sense and good judgment isimportant even in the apparently simple task of taking sam
10、ples.5.2 Use care to ensure that all containers, agitating equip-ment, and sampling apparatus are clean and that they can in noway contaminate the sample being taken. Slight contaminationof the paint sample may lead to false test results.5.3 The sample container should be dry and not cooler thanthe
11、temperature of the area in which the sample is to be taken.5.4 Because pigmented coatings are dispersions and notsolutions, finely divided pigment particles dispersed in thecoating vehicle may settle upon standing. Consequently, thor-ough and careful agitation before sampling is necessary torestore
12、the paint to its original, uniform condition. The methodof agitating or stirring is therefore of prime importance.5.5 As soon as samples of paint are taken from the shippingor storage container, place them in clean, nonreactive, dry,air-tight containers to prevent evaporation. Do not storesamples in
13、 plastic bottles because volatile solvents may diffusethrough the walls. Loss of volatile solvents may introduceerrors in such tests as viscosity, weight per gallon, andnonvolatile content as well as other properties. If cap liners areused, they should also be nonreactive with the material. If thesa
14、mple is self reactive or highly volatile, appropriate samplecontainer precautions should be taken to prevent over-pressurization of the container.1This practice is under the jurisdiction of ASTM Committee D01 on Paint andRelated Coatings, Materials, and Applications and is the direct responsibility
15、ofSubcommittee D01.20 on Quality Assurance and Statistics.Current edition approved Aug. 10, 2002. Published October 2002. Originallypublished as D 3925 80. Last previous edition D 3925 91 (1996).2Annual Book of ASTM Standards, Vol 06.01.3Available from American National Standards Institute (ANSI), 2
16、5 W. 43rd St.,4th Floor, New York, NY 10036.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.5.6 When representative samples have been obtained andpackaged in clean, closed containers, deliver them promptly tothe testing laboratory. D
17、uring the period between sampling anddelivery to the testing laboratory it is important that samples bekept at temperatures from 40 to 100F (5 to 40C) becauseextremes of temperature may change properties of some paintproducts.6. Procedure6.1 Because of differences in physical properties, somewhatdif
18、ferent procedures are required for agitating and samplingthose paints containing water as the volatile component incomparison to those containing organic solvents. For coatingswith no volatile ingredients, use the method applicable tomaterials containing organic solvents.6.2 Pigmented Coatings Conta
19、ining Organic SolventsMaterials in this group are of many different types but allcontain organic solvents, not water, as their volatile portion andthey are fluids, not dry powders.6.2.1 Small Containers:6.2.1.1 When the batch to be sampled is filled in smallcontainers and batch numbers are marked on
20、 the container, putall containers from the same batch together. From each batchselect at random 1 % of, but not more than five containers,using the next larger whole number if a fraction results. Forexample, if there are 275 containers in a batch, select three fortest.6.2.1.2 After selection of the
21、filled, unopened containers,thoroughly agitate or stir the contents by the best meansavailable. Acceptable methods of mixing are mechanical shak-ing or stirring or hand stirring with a paddle, followed by“boxing,” that is pouring back and forth between the originaland a clean empty container. Mechan
22、ical shakers are desirablefor most materials since there is thorough agitation in a closedcontainer. To prevent evaporation, agitate in a closed containerlacquers and other coatings containing a highly volatile sol-vent.6.2.1.3 Before mechanical shaking, open the container andcheck to be sure that t
23、he pigment has not caked on the bottomof the container. If this condition exists, stir manually to breakup the hard settling and then put the containers on themechanical shaker.Agitate paints having a weight per gallon of11 lb (1.3 g/mL) or less on the shaker for 10 min and those witha weight per ga
24、llon of more than 11 lb for 20 min.6.2.1.4 Once the contents have been thoroughly agitated,pour half of the material into an empty container and take a 1qt (1 L) (or smaller if taken from a container of 1 qt or less)sample from each half. Determine the weight per gallon oneach sample in accordance w
25、ith Test Method D 1475. The twodeterminations should not differ more than 0.5 %. If the resultsdiffer by more than this the paint is not thoroughly mixed.Return the material to the original container, stir again, andrepeat the test.6.2.2 Containers Larger than 5 Gal:6.2.2.1 30 and 55-Gal DrumsFrom e
26、ach batch select atrandom 5 % of but not more than three containers. Drums maybe stirred satisfactorily by several means. With open-headtypes, mechanical or manual stirring may be used. Some drumscontain their own agitators; drum shakers or rollers may also beused. After thorough agitation, take sam
27、ples from the top andbottom of the drum and compare weights per gallon asdescribed in 6.2.1.4.6.2.2.2 250 to 500-Gal Containers (Tote Tanks)Select atrandom 25 % of all containers for test. Take samples from topand bottom of the container and compare weight per gallondeterminations as described in 6.
28、2.1.4.6.2.2.3 Tank Wagons and Tank CarsSample each com-partment of the wagon or car. Pigmented paints and coatingspackaged in large containers are generally formulated to beessentially nonsettling. Therefore, take samples from the top,middle, and bottom of the container and make weight-per-gallon de
29、terminations before any vigorous stirring is done. Ifthe resulting tests fall within the limits described earlier, nofurther agitation is necessary. Samples may be obtained with aBacon-bomb sampler or a “thief” apparatus.6.3 Pigmented Coatings Containing Water:6.3.1 Handle pigmented coatings contain
30、ing water (latexpaints, etc.) in a slightly different manner from solvent-thinnedcoatings. Water-thinned paints, if stirred too vigorously, have atendency to incorporate air bubbles, which sometimes result inchanging the physical properties of the paint.6.3.2 With the above consideration, take the s
31、amples inaccordance with the same general procedure outlined in 6.2 forpaints containing organic solvents. If it has been necessary toshake, stir, or agitate a water-thinned paint vigorously, deaeratethe samples before the weight-per-gallon tests are run.6.4 Sampling from Tanks at the FactoryMix the
32、 materialin the tank thoroughly before completely filling two 1-qt (1-L)containers. If the containers are to be filled from a valve on thebottom or side of the tank, mix the material, draw off at least5 gal (20 L) through the valve and return to the tank beforetaking the sample.6.5 Sampling During F
33、illing of Containers at the FactoryAfter the material is thoroughly mixed in the tank and filling ofcontainers has commenced, take a 1-qt (1-L) sample whenabout 25 gal (100 L) have been filled and another when about25 gal remain to be filled.7. Keywords7.1 samplingD3925022ASTM International takes no
34、 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 determination of the validity of any such patent rights, and the riskof infringement of such rights, are entirely their own respons
35、ibility.This standard is subject to revision at any time by the responsible technical committee and must be reviewed every five years andif not revised, either reapproved or withdrawn. Your comments are invited either for revision of this standard or for additional standardsand should be addressed t
36、o ASTM International Headquarters. Your comments will receive careful consideration at a meeting of theresponsible technical committee, which you may attend. If you feel that your comments have not received a fair hearing you shouldmake your views known to the ASTM Committee on Standards, at the add
37、ress shown below.This standard is copyrighted by ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959,United States. Individual reprints (single or multiple copies) of this standard may be obtained by contacting ASTM at the aboveaddress or at 610-832-9585 (phone), 610-832-9555 (fax), or serviceastm.org (e-mail); or through the ASTM website(www.astm.org).D3925023
