1、Designation: F2496 05 (Reapproved 2011)1Standard Practice forDetermining the Scratch Hardness and Scrape Adhesion ofPrints and Coatings1This standard is issued under the fixed designation F2496; the number immediately following the designation indicates the year oforiginal adoption or, in the case o
2、f 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.1NOTERevised the units presentation and added a units statement editorially in October 2011.1. Scope1.1 Th
3、is practice describes procedures to obtain subjective,but comparative data for scratch hardness and scrape adhesionof coatings and color images produced by printers, copies andother reprographic devices.1.2 This method simulates conditions where the surface ofvarious substrates such as paper, film,
4、cloth, and so forth maybe subject to failure under mechanical force.1.3 This test method covers the determination of the scratchhardness and scrape adhesion of coatings. Results are ex-pressed in terms of force-to scratch coatings on substrates usedin printing.1.4 The values stated in inch-pound uni
5、ts are to be regardedas standard. The values given in parentheses are mathematicalconversions to SI units that are provided for information onlyand are not considered standard.1.5 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsib
6、ility 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:2.1.1 scratch hardnessthe force necessary to cut throughthe coating to the substrate.2.1.2 scrape adhesionscr
7、atch resistancethe force re-quired to scrape a path through the coating or print, when thestylus begins its motion. By moving a free edge of the testcoating against a round stylus or loop under a variable loadexpressed in grams, scrape resistance is determined as theminimum load in grams required to
8、 cut through the film to thesubstrate.3. Summary of Practice3.1 The scratch hardness and scrape adhesion is determinedby pushing the substrate with coating beneath a rounded stylusor loop that is loaded in increasing amounts (weights) until thecoating is scratched.4. Significance and Use4.1 The imag
9、e life of printed media displayed in bothtypical office and outdoor environments is dependent oncoating scratch resistance. While natural aging is the mostreliable method of assessing coating scratch resistance, thelength of the time required makes this method impractical formost materials.4.2 Facto
10、rs in the office and outdoor environments, such asheat, cold, thermal shock, ultraviolet/visible radiation andwater vapor can have similar effect on the scratch resistance ofcoatings and prints as mechanical force.4.3 Good scratch resistance is a prime consideration forcoated media and prints. Highl
11、y absorptive coatings in digitalprinting have a tendency to dusting, flaking and cracking whenfolded.4.4 This practice utilizing mechanical force allows com-parative studies of coated and printed media. It is most usefulin providing relative ratings for media which exhibit significantdifferences in
12、performance.5. Interferences5.1 Since the scratch resistance adhesion is dependent ontemperature and humidity, it is important that the effects ofmechanical force be assessed under the conditions appropriateto the end use applications. While printed media may behandled and displayed under a variety
13、of conditions, this testpractice is intended to measure scratch resistance in typicalindoor environments.5.2 The adhesion is dependent on temperature and should betested at the manufacturers recommended temperature for thebest performance.5.3 The scratch resistance of color images is dependent onthe
14、 printing mode, the type of color and the amount of appliedink.1This practice is under the jurisdiction of ASTM Committee F05 on BusinessImaging Products and is the direct responsibility of Subcommittee F05.07 on Ink JetImaging Products.Current edition approved Oct. 1, 2011. Published March 2012. Or
15、iginallyapproved in 2005. Last previous edition approved in 2005 as F249605. DOI:10.1520/F2496-05R11e1.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.5.4 The practice is intended to measure scratch resistance ofprinted media without
16、 specifying above-mentioned parameters.6. Apparatus6.1 Balanced Beam Scrape Adhesion and Mar Tester (Cata-log Number SG-8101)for example available from BykGard-ner2(Fig. 1) consisting of a balanced beam to which is secureda platform for supporting weights, and a rod at an angle of 45that holds the s
17、craping loop or the stylus. The rod shall be setso that the scraping loop or the rounded stylus contacts testsurfaces directly below the weights. On the other end of thebeam is a counter-weight. A cam is rotated to lower and raisethe stylus and a sample bed mounted on ball bearings is usedto move th
18、e test sample against the stationary stylus.6.2 The loop shall be 0.0825 in. (1.6 mm) diameter rod, bentinto a “U” shape with an outside radius of 0.128 6 0.002 in.(3.25 6 0.05 mm) and hardened to Rockwell HRC 56 to 58,and shall be a smooth finish.6.3 The round stylus shall be a smooth cylinder 0.28
19、4 in.(7.21 mm) OD and 0.138 in. (3.50 mm) high with attaching rod0.380 in. (9.67 mm) long for assembling and hardened toRockwell HRC 56 to 58.6.4 The loop and the stylus can be either chromium plated,nickel plated, or heat-treated polished steel.6.5 The testers are adjustable to accommodate flat spe
20、cimento 0.5 in. (12 mm) thick and 4 to 16 in. (100 to 400 mm) wideand long; the specimens should be at least 1 in. (25 mm) wide.6.6 Supplied with the Tester is a set of twelve slotted brassweights with storage track. In the adhesion test, weights areapplied in 100 g increments to a maximum of 2 kg.
21、It ismaximum recommended weight for paper substrate without itsdamage. Higher weights can be used for film and plasticsubstrates.7. Test Specimens7.1 The substrate, method of printing, ink or toner lay down,and handling of printed specimens shall be consistent with theiranticipated end use.7.2 The t
22、est specimens should be completely flat becausepaper curls can significantly alternate the scratch resistance.7.3 The test image can be any picture printed using printfiles containing the appropriate printer setup specific for eachapplication.7.4 The same test image and printer set up should be used
23、for comparison purposes.7.5 The recommended test image should consist of a stan-dardized arrangement of color patches printed using print filescontaining the appropriate printer setup specific for eachapplication. This test image should contain color patches atmaximum print density of 100 % for each
24、 of the primary colorsof cyan, magenta, yellow and black, 200 % for the secondarycolors of red, green, and blue, and 300 % for composite black.7.6 The recommended color patches should be rectangularwith minimum diameter of 1 by 8 in. (25.4 by 203 mm).7.7 It is recommended that the samples be conditi
25、oned 24 hafter printing. The actual testing time after printing should bepresented in the report.7.8 At least three test specimens have to be printed with atest image if prints scratch resistance is evaluated.8. Conditioning8.1 It is recommended that samples be conditioned at 23Cand 50 % RH for at l
26、east 24 h after coating or printing.Specimens should be visually inspected for surface irregulari-ties, which could adversely affect adhesion.8.2 The above conditioning step is pertinent only wheremedia evaluation or comparison is needed. Obviously, as aproduction tool, the conditioning period is no
27、t practical.Therefore, when media are coated in production, the specimensshould be obtained from each roll and checked as soon aspossible in a repeatable procedure appropriate to the operation.It is imperative that operators use caution in selecting andpreparing specimens to maintain good uniformity
28、.9. Procedures9.1 Tests should be carried out under temperature andhumidity conditions similar to those of end use applications.9.2 Test procedure can be carried using the rounded stylusor the loop. For paper substrates the round stylus is recom-mended if resistance to flaking, cracking is evaluated
29、.9.3 Ensure that the apparatus is level.9.4 Place the apparatus so that the weight holder is towardthe operator. This places the beam release on the operatorsright and allows freedom to move the test specimen manuallyunder the weighted scraping element. Insert the sharp circularrim into the holder a
30、s far as it will go and tighten the clampingscrew.9.5 Adjust the main bearing support so that the beam isbalanced in the horizontal plane when the loop is just touchingthe specimen surface. The alignment of the beam should besuch that the end of the loop is over the midline of the movabletable.9.6 E
31、xamine the round stylus or the loop. Ensure that theoriginal smooth surface of the loop is intact. If the contactingsurface is worn, reverse the loop. When both sides are worn,replace with a new loop.2The sole source of supply of the apparatus known to the committee at this timeis Byk-Gardner, River
32、s Park II, 9104 Guilford Road, Columbia, MD 21046. If youare aware of alternative suppliers, please provide this information to ASTMInternational Headquarters. Your comments will receive careful consideration at ameeting of the responsible technical committee,1which you may attend.FIG. 1 Balanced Be
33、am Scrape Adhesion TesterF2496 05 (2011)129.7 Raise the beam and lock it in the raised position. Wipethe round stylus with a clean cloth or chamois. Locate thespecimen on the siding platform against the stop so that thespecimen can be moved in the direction of the operator andthere is an area at lea
34、st 5 in. (100 mm) long by 0.5 in. (12 mm)wide on the sample parallel to the horizontal plane through thebeam.9.8 The stylus is moved in the direction of the operator andthe stylus is sliding on the surface of the tested materials.Moving the stylus in the opposite direction could crease softmaterials
35、 such as paper and thin film and can limit thereproducibility of the practice.9.9 Place weights on the weight support using an initialamount that is estimated to be appropriate for the particularcoating. Release the beam and carefully lower it until the looprests on the coated test specimen and the
36、full load is applied.Then slowly push the sliding platform in the direction of theoperator at approximate rate of 0.125 in./s (6 mm/s) for adistance of at least 5 in. (100 mm).9.10 Maximum Load Procedure:9.10.1 If the coating is scratched, continue the testing usingsuccessfully smaller loads (100 g
37、increments) until the coatingis not scratched. If the coating is not scratched by the initialscrape, continue the test using successive larger load (100 gincrements) until the coating is scratched or until the maximumload of 2 kg has been applied. Use a new area of the testsurface each time a scrape
38、 is made.9.10.2 When the critical load has been approximately lo-cated, repeat the test at least three times at each of threeloadings: above, below and at the load determined, in the firsttrial.Apply different loads in random fashion so that all scrapesat one load are not made in succession.9.10.3 F
39、or each applied load, tabulate the number of timesthe coating was scratched.9.11 Three Loads Procedure:9.11.1 Place 100-g load on the weight support. Release thebeam and carefully lower it until the round stylus ( smoothcylinder is recommended) rests on the coated test specimen andthe full load is a
40、pplied. Then slowly push the sliding platforminto the direction of the operator at a approximate rate of 0.125in./s (6 mm/s) for a distance of at least 5 in. (100 mm). Repeatthe procedure five times. The stylus has to follow the samepath.9.11.2 Place 200-g load on the weight support. Release thebeam
41、 and carefully lower it until the round stylus rests on thecoated test specimen and the full load is applied. Then slowlypush the sliding platform into the direction of the operator at aapproximate rate of 0.125 in./s (6 mm/s) for a distance of atleast 5 in. (100-mm). Repeat the procedure three time
42、s. Thestylus has to follow the same path.9.11.3 Place 500-g load on the weight support. Release thebeam and carefully lower it until the round stylus rests on thecoated test specimen and the full load is applied. Then slowlypush the sliding platform into the direction of the operator at aapproximate
43、 rate of 0.125 in./s (6 mm/s) for a distance of atleast 5 in. (100-mm). It is single path procedure.9.11.4 Repeat the test three times at each of three loading.Apply different loads in random fashion so that all scrapes atone load are not made in succession.9.11.5 Examine the coating surface. Rate a
44、dhesion accord-ing to the scale 15, where 1“poor” for the lowest rating and5“Excellent” as the highest rating. The average of three loadsis calculated.9.11.6 For each applied load, tabulate the rating and averagefor all three loads.10. Report10.1 Report the following information:10.1.1 Specimen iden
45、tification, including the printer,method of printing, and the media type,10.1.2 Relative humidity and temperature in the room,where printing is carried out, and time after printing,10.1.3 Load in grams at the scratch failure point,10.1.4 Each specimen rating,10.1.5 Average test result,10.1.6 The rou
46、nd stylus and the “U” shape loop surfacefinish, and10.1.7 Any unusual characteristics, that is, extremes orirregularities noted in test results. Include backing if requiredand the conditioning cycle if other than standard.11. Precision and Bias11.1 A statement of bias is not applicable in view of th
47、eunavailability of a standard reference for these properties.12. Keywords12.1 accelerate aging; adhesion; balanced beam scrape ad-hesion; balanced beam tester; bond strength; coatings; debond-ing; ink jet; media; printing; scrape adhesion; scratch hardness;scratch resistance; thicknessASTM Internati
48、onal 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 determination of the validity of any such patent rights, and the riskof infringement of such rights, are entirely thei
49、r 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 reapproved 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 feel that your comments have not received a fair hearing you shouldmake your views known to the ASTM
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