1、Designation: D3003 01 (Reapproved 2012)Standard Test Method forPressure Mottling and Blocking Resistance of OrganicCoatings on Metal Substrates1This standard is issued under the fixed designation D3003; the number immediately following the designation indicates the year oforiginal adoption or, in th
2、e case of revision, 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 This test method covers determination of the pressuremottling and sticking, or blockin
3、g resistance of organic coat-ings applied to coil-coated or factory-coated metal prior tofabrication.1.2 The values stated in SI units are to be regarded as thestandard. The values given in parentheses are for informationonly.1.3 This standard does not purport to address all of thesafety concerns, i
4、f 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. Terminology2.1 Definitions of Terms Specific to This Standard:2.1.1 blocking or sticki
5、ng, nthe condition wherein coatedsurfaces adhere to each other.2.1.2 pressure mottling, nfilm distortion or uneven patterngiving a change of gloss and nonuniform appearance. It isusually caused by pressures within a painted coil or stackedpainted sheets or other painted products.3. Summary of Test M
6、ethod3.1 The coated metal is cut into suitably sized panels. Astack of these panels is then subjected to a specified pressureand temperature for a specified time to permit any pressuremottling and sticking or blocking to develop. The applied heatof the test apparatus is turned off and, after cooling
7、, thespecimens are examined for any signs of sticking (or blocking),and mottling. The results are rated on the 0 to 10 scale and maybe used in accepting or rejecting the coating in accordance withstandards established between the purchaser and the seller.4. Apparatus24.1 Suitable Hydraulic or Mechan
8、ical Press or Vise may beused. The equipment shall be capable of producing the requiredtest pressure in kilopascals (or pounds-force per square inch)and be equipped with a suitable device for measuring the forceapplied.5. Test Specimens and Conditions5.1 At least four, and preferably six, flat panel
9、s shall be cutfrom the coated stock, the age of which shall be within thelimits agreed upon between the purchaser and the seller.5.2 Panels should be at least 100 by 70 mm (4 by 2.5 in.) toprovide an adequate area for assessing the results. Where theequipment does not provide adequate pressure, smal
10、ler panelsmay be used. The minimum recommended size is 50 by 50 mm(2 by 2 in.).5.3 Use only flat panels. If necessary, file the edges smoothto ensure maximum contact between the surfaces. When theequipment permits, panels larger than the pressure plates maybe used, thus eliminating any effect from u
11、neven edges. Withthis method, the kilopascals (or pounds of force per squareinch) is calculated using only the panel area within the pressureplates.5.4 The film thickness of the coating under test shall be asspecified or agreed upon between the purchaser and the seller.5.5 The coated stock shall be
12、tested under the conditions ofpressure, temperature, and time mutually agreed upon betweenthe purchaser and the seller. Pressures ranging from 750 to2400 kPa (110 to 350 psi), temperatures from 43 to 60C (110to 140F), and times of 2 to 16 h have been used.5.6 In the absence of agreed or specified te
13、st conditions, apressure of 750 6 35 kPa (110 6 5 psi), a temperature of 436 1.5C (110 6 3F), and a time of 16 h shall be used.5.7 The total force applied is measured by a suitable gageand the pounds of force per kilopascals (or square inch) is1This test method is under the jurisdiction of ASTM Comm
14、ittee D01 on Paintand Related Coatings, Materials, and Applications and is the direct responsibility ofSubcommittee D01.53 on Coil Coated Metal.Current edition approved June 1, 2012. Published August 2012. Originallyapproved in 1971. Last previous edition approved in 2006 as D3003 01 (2006).DOI: 10.
15、1520/D3003-01R126.2Suitable equipment includes presses and drill press vises modified for use witha torque wrench if agreed upon between purchaser and seller (Hensley, W. L.,“Pressure Mottling Test,”Journal of Paint Technology, Vol 40, No. 517, February1968, p. 54A).Copyright ASTM International, 100
16、 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States1calculated by dividing the force by the area in square inches ofone side of one panel.6. Procedure6.1 Stack the panels face to back as used in production withboth face and back coatings applied. Limit the number ofpanel
17、s in the test to the quantity that can be heated rapidly toand maintained at the correct panel temperature throughout thetest.6.2 For presses having heating units, place the test panels inthe press and bring the heating platens in contact but with lightpressure. Turn on the heating unit, and heat th
18、e panels to therequired test temperature. When this temperature is reached,apply the required pressure and maintain it for the specifiedtime (6.4).6.3 Where the apparatus does not have built-in heatingunits, preheat the mechanical press or vise. Place the panels inthe press at room temperature with
19、very light contact and heatthe unit (press and panels) in an oven to the required tempera-ture. Then apply the proper pressure and return the unit to theoven for the specified time.6.4 Record the time only after the specified temperature andpressure are reached. Check the temperature and pressure at
20、intervals during the test.6.5 At the end of the specified time, turn off the heat andallow the panels to cool to room temperature under pressurebefore removal and separation.6.6 After removal from the press, grade the panels sepa-rately for both sticking (or blocking) and mottling in accor-dance wit
21、h Table 1. In assessing the results, ignore effects dueto sharp or uneven edges.6.7 Maintain panels that are to be reassessed for a mottlinggrade in accordance with Table 1 after a 24-h recovery periodat 24 6 3C (75 6 5F).6.8 For both properties assign each coating a grade that isthe arithmetic mean
22、 of all panels tested.7. Report7.1 Report the following information for each coating:7.1.1 Equipment used,7.1.2 Number of panels tested,7.1.3 Pressure (or force applied and surface area of testcoupons),7.1.4 Temperature and heating process (built-in or oven),7.1.5 Time,7.1.6 Grade for sticking or bl
23、ocking,7.1.7 Grade for mottling,7.1.8 Age of specimen,7.1.9 Size of panels tested,7.1.10 Dry film thickness of coupon, and7.1.11 Evaluation time (for example, immediate, 24 h, etc).8. Precision and Bias8.1 PrecisionIn an interlaboratory test of this test method,two operators in each of seven laborat
24、ories tested two differentcoatings, subjected to two treatments (pressure, temperature,and duration) and rated them for sticking (S), and pressuremottling (PM). The within-laboratory and between laboratorypooled standard deviations were found to be as follows:Pooled Standard DeviationsRatingParamete
25、rWithin-LaboratoryBetweenLaboratoryS 0.42 1.10PM 0.38 1.06Average 0.40 1.08Based on these results the following criteria should be usedin judging the acceptability of results at the 95 % confidencelevel.8.1.1 RepeatabilityTwo results, each the mean of the twosets of panels, obtained by the same oper
26、ator should beconsidered suspect if they differ by more than 1.2 units.8.1.2 ReproducibilityTwo results, each the mean of twosets of panels, obtained by operators in different laboratoriesshould be considered suspect if they differ by more than 3.7units.TABLE 1 ClassificationNOTE 1Intermediate grade
27、s are permissible to distinguish small differences.NOTE 2Reasonable force is defined as that which can be exerted by the fingers only, using the fingernails as the only prying instrument.NOTE 3The transfer of components of one coating onto or into another coating is also known as offsetting or picko
28、ff.Grade Sticking or Blocking Grade Mottling10 Panels fall apartno sticking. 10 no mottling immediately after separation.8 Slight tackiness or panels pull apart easily. 8 no mottling after 24-h separation.6 Panels pull apart with effort. No flexing or prying is required toaid separation.6 light perm
29、anent mottling after 24-h separation.4 Panels pull apart using reasonable force. Flexing may be re-quired (Note 2).4 heavy permanent mottling after 24-h separation.2 Panels require prying apart with a spatula or similar instrument. 2 light pickoff or transfer of one or both coatings (Note 3).0 Panel
30、s block together so they cannot be separated with aspatula or similar instrument, without using extreme force.0 one or both coatings show heavy pickoff down to the metal orbasecoat; or block together (Note 3).D3003 01 (2012)28.2 BiasThe procedure in this test method has no biasbecause only the value
31、 of pressure mottling is defined in thistest method.9. Keywords9.1 blocking resistance; pressure mottlingASTM 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
32、 determination of the validity of any such patent rights, and the riskof infringement of such rights, are entirely their own responsibility.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 reapprov
33、ed or withdrawn. Your comments are invited either for revision of this standard or for additional standardsand should be addressed to ASTM International Headquarters. Your comments will receive careful consideration at a meeting of theresponsible technical committee, which you may attend. If you fee
34、l that your comments have not received a fair hearing you shouldmake your views known to the ASTM Committee on Standards, at the address shown below.This standard is copyrighted by ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959,United States. Individual repr
35、ints (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). Permission rights to photocopy the standard may also be secured from the ASTM website (www.astm.org/COPYRIGHT/).D3003 01 (2012)3
