1、Designation: D 6487 04Standard Practice forPreparing Prints of Paste Printing Inks by Rollouts on aLaboratory Flat-Bed Press1This standard is issued under the fixed designation D 6487; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision
2、, the year 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. Scope*1.1 This practice covers the procedure for preparing printsof paste inks using rollouts on a flat-bed labo
3、ratory proof press.The initial method was developed by the National Printing InkResearch Institute.21.2 This practice is applicable to the preparation of single-color solid-area prints by the dry offset process (also known asLetterset) on a flat substrate such as paper or metal. It canreadily be ada
4、pted to print by direct letterpress.NOTE 1The proofing press described in this practice can also be usedwith printing gages in accordance with Practice D 6846.1.3 This practice is applicable primarily to lithographic andletterpress inks that dry by oxidation or penetration. With theaddition of appro
5、priate drying or curing equipment, it is alsoapplicable to other systems such as heat-set or energy-curable.1.4 The instructions in this practice are intended to mini-mize the within-print and among-operator variability inherentin hand operations.1.5 This practice does not measure the actual film th
6、icknesson the print, but evaluates film thickness equivalence by visualor instrumental comparisons of optical density.1.6 The values stated in SI units are to be regarded as thestandard. The values given in parentheses are for informationonly.1.7 This standard does not purport to address all of thes
7、afety concerns, if any, associated with its use. It is theresponsibility of the users of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use. Specific precau-tions are given in Section 7.2. Referenced Documents2.
8、1 ASTM Standards:3D 6073 Test Method for Relative Setting of Heatset PrintingInks by the Sinvatrol TesterD 6846 Practice for Preparing Prints of Paste Printing Inkswith a Printing Gage2.2 ANSI Standards:4PH 2.17 Geometric Conditions for Reflection DensityPH 2.18 Spectral Conditions for the Measureme
9、nt of Opti-cal DensityPH 2.30 Viewing Conditions for Graphic Arts andPhotographyColor Prints, Transparencies and Photome-chanical ReproductionsCGATS.4 Graphic TechnologyGraphic Arts ReflectionDensitometry MeasurementsTerms, Equations, ImageElements and ProceduresCGATS.5 Graphic TechnologySpectral Me
10、asurements andColormetric Computation for Graphics Arts Images3. Summary of Practice3.1 The equipment is set up as described in Annex A1. Inorder to make a print, the test ink is metered onto a brayer,rolled out evenly on the distribution plate according to aspecified pattern, and then transferred t
11、o the printing plate. Theappropriate stock is clipped onto the impression plate, and theblanket cylinder is rolled over the inked plate six timesfollowed by once over the stock.3.2 After the print is set, it is checked against the targetoptical density instrumentally or by visual comparison with ast
12、andard print. Subsequent prints are made until the targetoptical density has been achieved.1This practice is under the jurisdiction of ASTM Committee D01 on Paint andRelated Coatings, Materials, and Applications and is the direct responsibility ofSubcommittee D01.56 on Printing Inks.Current edition
13、approved June 1, 2004. Published July 2004. Originally approvedin 1999. Last previous edition approved in 2001 as D 6487 - 01.2“The NPIRI Standard Procedure for Preparing Little Joe Prints,” American InkMaker, March 1994, pp. 42-50.3For referenced ASTM standards, visit the ASTM website, www.astm.org
14、, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.4Available from American National Standards Institute, 13thFloor, 11 W. 42ndStreet, New York, NY 10036 or Committee on Graphic Ar
15、ts Technical Standards,1899 Preston White Drive, Reston, VA 20191-4367.1*A Summary of Changes section appears at the end of this standard.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.4. Significance and Use4.1 Laboratory proofing o
16、f ink is necessary to establish areproducible prediction of print appearance and performanceproperties, most of which are highly sensitive to ink filmthickness. The apparatus described in this practice has foundwide use for routine control proofing because it provides aneconomical method for produci
17、ng reasonably large prints atfilm thicknesses comparable to those obtained on productionpresses.4.2 This practice does not duplicate the dynamics of a highspeed press, nevertheless, it is useful for quality control and forspecification acceptance between the producer and the user.5. Apparatus5.1 Lab
18、oratory Flat-Bed Proof Press5, having a press bedapproximately 914 mm (36 in.) long and 260 mm (1014 in.)wide, and a blanket6(impression) cylinder having a circum-ference of approximately 370 mm (1412 in.) such that thecylinder can make two revolutions down the length of the bed.Integral components
19、include a distribution plate, printing plate,inking track guides, and impression plate, (see Fig. 1). Thestandard printing plate is 100 by 152 mm (4 by 6 in.).5.2 Ink Pipet, or balance accurate to 0.001 g ink.5.3 Torque Screw Driver.5.4 Ink Knives.5.5 Brayer5,6, with a 63.5-mm (212-in.) diameter and
20、152-mm (6-in.) length.5.6 Standard Daylight, preferablyaD50light sourceconforming to ANSI Standard PH 2.30.5.7 Reflection Densitometer, (Optional), conforming toANSI Standard PH 2.17, having a set of Status T filtersconforming to ANSI Standard 2.18, and used according toCGATS.4.NOTE 2The filter syst
21、ems in typical densitometers are suitable onlyfor use with black, white, and the three process colors (yellow, magentaand cyan).5.8 Spectrophotometer, (Optional), hand-held, calibratedaccording to manufacturers instructions and used according toCGATS.5.6. Materials6.1 Ink Sample.6.2 Specification fo
22、r the target optical density; alternatively,a reference print to be matched.6.3 Printing Substrate such as paper or paperboard cut toapproximately 140 by 210 mm (512 by 812 in.).6.4 Solvent, appropriate to ink system.6.5 Lint-free Rags or Tissue.6.6 Shim Stock, metal or plastic, the same size as the
23、printing plate and 0.5, 1, 2, 5 or 10 mils in thickness.7. Hazards7.1 WarningSince solvents may be hazardous to the skinand eyes, wear rubber gloves and safety glasses during cleanupto avoid solvent contact with skin and eyes. In case of contact,wash skin with water; flush eyes for 15 min with water
24、 and calla physician. See suppliers Material Safety Data Sheets forfurther information on each solvent used.7.2 Equipment CautionsAvoid any operation that willscratch the metal distribution and printing plates or damage therubber blanket on the impression cylinder.8. Procedure for Dry Offset Printin
25、g (Letterset)8.1 Prepare the proofing press as described in Annex A1.Note that A1.5 covers older models having a crank-handledrive.A1.6 covers newer models having a push-handle drive asseen in Fig. 1.8.2 Clean press with appropriate solvent and lint-free rag ortissue. Remove lint from blanket and pr
26、inting plate using acamel hair brush.8.3 Place guide tracks against printing plate and place a 140by 210-mm (512 by 812-in.) piece of test stock on theimpression plate.5The apparatus used to develop this method was the Little Joe Offset ColorProofing Press.6For printing ultra violet (UV) systems, us
27、e a special blanket and brayerformulated for the purpose.FIG. 1 Laboratory Flat-Bed Press Equipped with Push Handle, Set Up for Dry Offset ProofingD64870428.4 Determine the approximate amount of ink that will givethe proper density. If uncoated stock, start with 0.6 mL or 0.6g of ink. For coated sto
28、ck, start with 0.4 mL or 0.4 g of ink.8.5 Using an ink knife or a pipet, apply the ink to the brayerevenly across the roller.8.6 Roll the ink on the distribution plate with the brayeruntil a uniform ink film is created and the entire distributionplate has been used.8.7 Once a uniform film exists, ro
29、ll the brayer from cornerto corner of the ink distribution plate to make a single “X”pattern. Then move the brayer from top to bottom and bottomto top without lifting (2 passes) along the middle of thedistribution plate. Turn brayer 180 (feet to point in oppositedirection) and repeat “X” pattern and
30、 top to bottom and bottomto top motion.8.8 Apply ink to printing plate with six passes of brayerusing a smooth motion (one pass is motion in one directiononly, left to right or right to left). Do not lift brayer betweenpasses. Pressure applied will depend on the ink rheology butlast pass (dressing p
31、ass) should be less than the pressure for theprevious five passes. Push guide tracks away from printingplate.8.9 Repeat 8.7 and 8.8 to ink the brayer and again apply inkto the printing plate. Push guide tracks away from printingplate.8.10 Apply ink to the blanket by engaging cylinder, andpass in for
32、ward motion over printing plate stopping before theimpression plate. Disengage cylinder and return.8.11 Repeat 8.10 (apply ink to the blanket) for six blanketpasses over the printing plate (Blanket is inked in forwardmotion only).8.12 Repeat 8.7 (inking the brayer), 8.8 (inking the printingplate), a
33、nd 8.9.8.13 Prepare first print by engaging the blanket cylinder androlling it over the printing plate and the paper on the impres-sion plate in a rapid continuous motion.8.14 Discard this print.8.15 Repeat 8.7 (inking the brayer), 8.8 (inking the plate),8.9, and 8.13 (making the print), and keep th
34、is print.8.16 Examine the print from 8.15, preferably under astandard light source. If the operator believes the target densityhas been reached, prepare three more prints following thedirections in 8.15. If the density is wrong, clean the press andstart this procedure at 8.3 with a different amount
35、of ink.8.17 Once four acceptable prints have been made, clean thepress with an appropriate solvent and lint-free rags or tissues.8.18 For inks that dry by penetration or oxidation, lay the“good” prints out singly on a bench top or clip to a line. Waitan appropriate amount of time prior to making tes
36、t measure-ments, for example, 15 to 30 min for initial densitometric orspectrophotometric evaluations, 72 h for chemical resistancetests.NOTE 3For heat-set inks, apply heat or run through the Sinvatrol inaccordance with Test Method D 6073. Energy-curable inks should be runthrough a UV lamp or other
37、appropriate apparatus.NOTE 4For letterpress printing, follow the procedure for dry offsetprinting with the following exceptions: In 8.3, tape or otherwise mount thestock on the blanket cylinder, not on the impression plate. Skip 8.10-8.12.In 8.13, roll the blanket cylinder containing the stock over
38、the inkedprinting plate and then stop.9. Instrumental Verification of Optical Density9.1 If the print is black, white, or a process color, use adensitometer with the appropriate filter and black backing.Otherwise, use a hand-held spectrophotometer. After the printhas set sufficiently (15 to 30 min),
39、 make five measurements,one in each corner 25 mm (1 in.) from each edge and one in thecenter, and compute the mean. A transparent template with fiveholes can be constructed for this purpose. Compute grand meanof mean reading per print to arrive at mean reading per test.9.2 A small decrease in optica
40、l density may occur betweenthe initial measurements taken after prints were made and thosetaken 24 h later. This density decrease should be accounted forso that the final dry average density matches the target opticaldensity.9.3 When comparing results between laboratories, densito-meters must be cal
41、ibrated to the same reference standard.10. Keywords10.1 dry offset proofing; letterset proofing; paste printinginks; printing inks; proofing of inksANNEX(Mandatory Information)A1. SETTING UP THE PROOF PRESSNOTE A1.1For printing UV inks, see Footnote 6.A1.1 Tighten blanket to 150 mm/kg (6-in.-pounds)
42、 using atorque screw driver.A1.2 Use the standard 100 by 150-mm (4 by 6-in.) printingplate. Mark the bottom of the plate “Leading Edge” and“Trailing Edge” and position it in this manner for every test.Mark outline of plate on bed to maintain plate position.A1.3 Mark each guide track “Far” or “Near”
43、and mark theirpositions on the bed to maintain position.A1.4 A smooth noncompressible shim should be placed ontop of the impression plate to provide a smooth surface forprinting. This may necessitate removal of one of the metalshims under the impression plate.A1.5 For older presses (models having a
44、crank-handledrive), adjust height and level of printing and impression platesto produce uniform print in the following manner:D6487043A1.5.1 Hand tighten screw on printing plate and positionguide tracks against plate.A1.5.2 Clean all surfaces with appropriate solvent andlint-free rags or tissues.A1.
45、5.3 Apply 0.6 mL or 0.6 g of ink to the brayer uniformlydirectly from the pipet or with an ink knife.A1.5.4 Roll out the ink on the ink distribution plate until auniform film is obtained. Minimize time to prevent excessivedrying.A1.5.5 To prepare brayer for application of ink to theprinting plate, r
46、oll brayer diagonally from corner to corner ofthe ink distribution plate to make a single “X” pattern. Thenmove brayer from top to bottom and bottom to top withoutlifting (2 passes) along middle of the ink distribution plate.Turn the brayer 180 (feet point in opposite direction) and rollbrayer diago
47、nally from corner to corner of the ink distributionplate to make a single “X” pattern. Then move brayer from topto bottom and bottom to top without lifting (2 passes) alongmiddle of the ink distribution plate.A1.5.6 Apply ink to printing plate with 6 passes of brayerusing a smooth motion (one pass i
48、s motion in one directiononly, left to right or right to left). Do not lift brayer betweenpasses. Pressure applied will depend on the ink rheology butthe last pass (dressing pass) should be less than the pressure forthe previous 5 passes. Push guide tracks away from printingplate.A1.5.7 Disengage bl
49、anket cylinder by turning handle on topof carriage counter clockwise to the stop position.A1.5.8 Roll blanket cylinder to a position located about 12mm (12 in.) past leading edge of printing plate. Engage blanketcylinder by turning handle on top of carriage clockwise to stopposition.A1.5.9 Maintain blanket in this position on printing platefor1stoproduce an ink stripe on blanket and an ink free stripeon the printing plate.A1.5.10 Disengage blanket cylinder and roll ahead to posi-tion 12 mm (12 in.) before trailing edge of printing plate.Engage cylinder and make
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