1、Designation: F 2496 05Standard Practice forDetermining the Scratch Hardness and Scrape Adhesion ofPrints and Coatings1This standard is issued under the fixed designation F 2496; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the y
2、ear of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.1. Scope1.1 This practice describes procedures to obtain subjective,but comparative data for scratch hardness and scrape a
3、dhesionof 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, cloth, and so forth maybe subject to failure under mechanical force.1.3 This test method covers the determin
4、ation 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 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of the user of th
5、is 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 adhesionscratch resistancethe forc
6、e 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 cut through the film t
7、o 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 image life of printed media
8、 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 Factors in the office and ou
9、tdoor 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. Highly absorptive coatings i
10、n 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 performance.5. Interfer
11、ences5.1 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 of conditions, this tes
12、tpractice 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 printing mode, the typ
13、e of color and the amount of appliedink.5.4 The practice is intended to measure scratch resistance ofprinted media without specifying above-mentioned parameters.1This practice is under the jurisdiction of ASTM Committee F05 on BusinessImaging Products and is the direct responsibility of Subcommittee
14、 F05.07 on Ink JetImaging Products.Current edition approved June 1, 2005. Published June 2005.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.6. Apparatus6.1 Balanced Beam Scrape Adhesion and Mar Tester (Cata-log Number SG-8101)for e
15、xample 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 scraping loop or the stylus. The rod shall be setso that the scraping loop or the rounded stylus contacts testsurfaces directly bel
16、ow 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 the test sample against the stationary stylus.6.2 The loop shall be 1.6 mm (0.0825 in.) diameter rod, bentinto a “U” shape with an o
17、utside radius of 3.25 6 0.05 mm(0.128 6 0.002 in.) and hardened to Rockwell HRC 56 to 58,and shall be a smooth finish.6.3 The round stylus shall be a smooth cylinder 7.21 mm(0.284 in.) OD and 3.50 mm (0.138 in.) high with attaching rod9.67 mm (0.380 in.) long for assembling and hardened toRockwell H
18、RC 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 specimento 12 mm (0.5 in.) thick and 100 to 400 mm (4 to 16 in.) wideand long; the specimens should be at least 25 mm (1 in.) wide.6.
19、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. It ismaximum recommended weight for paper substrate without itsdamage. Higher weights can be used for film and plasticsubstrates.7
20、. 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 test specimens should be completely flat becausepaper curls can significantly alternate the scratch resistance.7.3 The test image c
21、an 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 usedfor comparison purposes.7.5 The recommended test image should consist of a stan-dardized arrangement of color patches printed usin
22、g print filescontaining the appropriate printer setup specific for eachapplication. This test image should contain color patches atmaximum print density of 100 % for each of the primary colorsof cyan, magenta, yellow and black, 200 % for the secondarycolors of red, green, and blue, and 300 % for com
23、posite black.7.6 The recommended color patches should be rectangularwith minimum diameter of 25.4 by 203 mm (1 by 8 in.).7.7 It is recommended that the samples be conditioned 24 hafter printing. The actual testing time after printing should bepresented in the report.7.8 At least three test specimens
24、 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 least 24 h after coating or printing.Specimens should be visually inspected for surface irregulari-ties, which could adversely affe
25、ct adhesion.8.2 The above conditioning step is pertinent only wheremedia evaluation or comparison is needed. Obviously, as aproduction tool, the conditioning period is not practical.Therefore, when media are coated in production, the specimensshould be obtained from each roll and checked as soon asp
26、ossible in a repeatable procedure appropriate to the operation.It is imperative that operators use caution in selecting andpreparing specimens to maintain good uniformity.9. Procedures9.1 Tests should be carried out under temperature andhumidity conditions similar to those of end use applications.9.
27、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.9.3 Ensure that the apparatus is level.9.4 Place the apparatus so that the weight holder is towardthe operator. This places the b
28、eam release on the operatorsright and allows freedom to move the test specimen manuallyunder the weighted scraping element. Insert the sharp circularrim into the holder as far as it will go and tighten the clampingscrew.9.5 Adjust the main bearing support so that the beam isbalanced in the horizonta
29、l 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 Examine the round stylus or the loop. Ensure that theoriginal smooth surface of the loop is intact. If the contactingsurface is wor
30、n, reverse the loop. When both sides are worn,replace with a new loop.9.7 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 the2The sole source of supply of the apparatus known to
31、the committee at this timeis Byk-Gardner, Rivers 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 com
32、mittee,1which you may attend.FIG. 1 Balanced Beam Scrape Adhesion TesterF2496052specimen can be moved in the direction of the operator andthere is an area at least 100 mm (5 in.) long by 12 mm (0.5 in.)wide on the sample parallel to the horizontal plane through thebeam.9.8 The stylus is moved in the
33、 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 such as paper and thin film and can limit thereproducibility of the practice.9.9 Place weights on the weight support using an initialamoun
34、t 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 full load is applied.Then slowly push the sliding platform in the direction of theoperator at approximate rate of 6 mm/s (0.125 in./s) for
35、adistance of at least 100 mm (5 in.).9.10 Maximum Load Procedure:9.10.1 If the coating is scratched, continue the testing usingsuccessfully smaller loads (100 g increments) until the coatingis not scratched. If the coating is not scratched by the initialscrape, continue the test using successive lar
36、ger 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 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: abov
37、e, 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 For 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 weigh
38、t support. Release thebeam and carefully lower it until the round stylus ( smoothcylinder is recommended) rests on the coated test specimen andthe full load is applied. Then slowly push the sliding platforminto the direction of the operator at a approximate rate of 6mm/s (0.125 in./s) for a distance
39、 of at least 100 mm (5 in.).Repeat the procedure five times. The stylus has to follow thesame path.9.11.2 Place 200-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 p
40、latform into the direction of the operator at aapproximate rate of 6 mm/s (0.125 in./s) for a distance of atleast 100-mm (5 in.). Repeat the procedure three times. 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 ro
41、und 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 6 mm/s (0.125 in./s) for a distance of atleast 100-mm (5 in.). It is single path procedure.9.11.4 Repeat the test three times at e
42、ach 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 adhesion accord-ing to the scale 15, where 1“poor” for the lowest rating and5“Excellent” as the highest rating. The average of three loadsis
43、 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 identification, including the printer,method of printing, and the media type,10.1.2 Relative humidity and temperature in the room,where printin
44、g 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 round stylus and the “U” shape loop surfacefinish, and10.1.7 Any unusual characteristics, that is, extremes orirregularities noted in test res
45、ults. 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 theunavailability of a standard reference for these properties.12. Keywords12.1 accelerate aging; adhesion; balanced beam scrape ad-hesion; b
46、alanced beam tester; bond strength; coatings; debond-ing; ink jet; media; printing; scrape adhesion; scratch hardness;scratch resistance; thicknessASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this standard. Users o
47、f 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 responsibility.This standard is subject to revision at any time by the responsible technical committee and must be reviewed every fiv
48、e 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 c
49、ommittee, 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 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 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).F2496053
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