1、Designation: D6487 10Standard Practice forPreparing Prints of Paste Printing Inks Using a HandOperated Laboratory Flat-Bed Press1This standard is issued under the fixed designation D6487; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revis
2、ion, 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. Scope*1.1 This practice covers the procedure for preparing printsof paste inks using a hand operated flat-bed
3、laboratory proofpress. The initial method was developed by the NationalPrinting Ink Research 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
4、 adapted to print by direct letterpress.3NOTE 1The proofing press described in this practice can also be usedwith printing gages in accordance with Practice D6846.1.3 This practice is applicable primarily to lithographic andletterpress inks that dry by oxidation or penetration. With theaddition of a
5、ppropriate 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 fil
6、m thicknesson the print, but evaluates film thickness equivalence by visualor instrumental comparisons of reflection 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
7、of thesafety 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 Docu
8、ments2.1 ASTM Standards:4D6073 Test Method for Relative Setting of Heatset PrintingInksD6846 Practice for Preparing Prints of Paste Printing Inkswith a Printing GageD7305 Test Method for Reflection Density of Printed Mat-ter2.2 ANSI Standards:5PH 2.30 Viewing Conditions for Graphic Arts andPhotograp
9、hyColor Prints, Transparencies and Photome-chanical ReproductionsCGATS.5 Graphic TechnologySpectral Measurements andColormetric Computation for Graphics Arts Images3. Summary of Practice3.1 Prints are prepared by metering the test ink onto abrayer, rolled out evenly, on the distribution plate accord
10、ing toa specified pattern, and then transferred to the printing plate.The substrate is clipped onto the impression plate, and theblanket cylinder is rolled over the inked plate six timesfollowed by once over the substrate.3.2 After the print is dry to the touch, it is evaluated versusthe target refl
11、ection density instrumentally or by visual com-parison with a standard reference print. Subsequent prints canbe made if the target reflection density has not been achievedor if a visual assessment indicates that either more or less inkis needed.4. Significance and Use4.1 Laboratory proofing of ink i
12、s 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 found1This practice is under the jurisdiction of ASTM Committee D01 on Paint andRelated Coatings, Mat
13、erials, and Applications and is the direct responsibility ofSubcommittee D01.56 on Printing Inks.Current edition approved July 15, 2010. Published July 2010. Originallyapproved in 1999. Last previous edition approved in 2004 as D6487 - 04. DOI:10.1520/D6487-10.2“The NPIRI Standard Procedure for Prep
14、aring Little Joe Prints,” AmericanInk Maker, March 1994 , pp. 42-50.3The apparatus used to develop this method was the Little Joe Offset ColorProofing Press.4For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of AS
15、TMStandards volume information, refer to the standards Document Summary page onthe ASTM website.5Available from American National Standards Institute, 13thFloor, 11 W. 42ndStreet, New York, NY 10036 or Committee on Graphic Arts Technical Standards,1899 Preston White Drive, Reston, VA 20191-4367.1*A
16、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.wide use for routine control proofing because it provides aneconomical method for producing reasonably large prints atfilm
17、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 userwhere there is an agreed upon specification for reflec
18、tiondensity or standard reference print.5. Apparatus5.1 Laboratory Flat-Bed Proof Press3, 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
19、revolutions down the length of the bed.Integral components include a distribution plate, printing plate,inking track guides, and impression plate (see Fig. A1.1). Thestandard printing plate is 100 by 152 mm (4 by 6 in.).5.2 Ink Pipette, or balance accurate to 0.001 g ink.5.3 Torque Screw Driver.5.4
20、Ink Knives.5.5 Brayer, with a 63.5-mm (212-in.) diameter and 152-mm(6-in.) length.5.6 Standard Daylight, preferably a D 50 light source con-forming to ANSI Standard PH 2.30.5.7 Reflection Densitometer (optional), conforming to TestMethod D7305.NOTE 2The filter systems in typical densitometers are su
21、itable onlyfor use with black, white, and the three process colors (yellow, magentaand cyan).5.8 Spectrophotometer (optional), calibrated according tomanufacturers instructions and used according to CGATS.5.6. Materials6.1 Ink Sample.6.2 Reference Print (optional).6.3 Printing Substrate cut to appro
22、ximately 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 theprinting 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 rubb
23、er gloves and safety glasses during cleanupto avoid solvent contact with skin and eyes. See suppliersMaterial Safety Data Sheets for further information on eachsolvent used.7.2 Equipment CautionsAvoid any operation that willscratch the metal distribution and printing plates or damage therubber blank
24、et on the impression cylinder.8. Flatbed Press Set Up8.1 Prepare the proof press as described in Annex A1 asseen in Fig. A1.1.9. Procedure for Dry Offset Printing (Letterset)9.1 Inspect and ensure that the printing plate, blanket andprint roll out area are clean and free from lint.9.2 Place guide tr
25、acks against printing plate and place a 140by 210-mm (512 by 812 in.) piece of test substrate on theimpression plate.9.3 Determine the approximate amount of ink that will givethe proper density. If uncoated paper, start with 0.6 mL or 0.6g of ink. For coated paper, start with 0.4 mL or 0.4 g of ink.
26、9.4 Using an ink knife or a pipette, apply the ink to thebrayer evenly across the roller.9.5 Roll the ink on the distribution plate with the brayeruntil a uniform ink film is created and the entire distributionplate has been used.9.6 Once a uniform film exists, roll the brayer from cornerto corner o
27、f 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 top to bottom and bottomto top moti
28、on.9.7 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 pass) should be less than the pressur
29、e for theprevious five passes. Push guide tracks away from printingplate.9.8 Repeat 9.6 and 9.7 to ink the brayer and again apply inkto the printing plate. Push guide tracks away from printingplate.9.9 Apply ink to the blanket by engaging cylinder, and passin forward motion over printing plate stopp
30、ing before theimpression plate. Disengage cylinder and return.9.10 Repeat 9.9 (apply ink to the blanket) for six blanketpasses over the printing plate (blanket is inked in forwardmotion only).9.11 Repeat 9.6 (inking the brayer), 9.7 (inking the printingplate), and 9.8.9.12 Prepare first print by eng
31、aging the blanket cylinder androlling it over the printing plate and the substrate on theimpression plate in a rapid continuous motion.9.13 Discard this print.9.14 Repeat 9.6 (inking the brayer), 9.7 (inking the plate),9.8, and 9.12 (making the print), and keep this print.9.15 Examine the print from
32、 9.14, preferably under astandard light source as per ANSI PH 2.30. If the operatorbelieves the target density has been reached, prepare threemore prints following the directions in 9.14. If the density iswrong, clean the press and start this procedure at 9.2 with adifferent amount of ink.9.16 Once
33、four acceptable prints have been made, clean thepress with an appropriate solvent and lint-free rags or tissues.6For printing ultra violet (UV) systems, use a special blanket and brayerformulated for the purpose.D6487 1029.17 For inks that dry by penetration or oxidation, lay the“good” prints out si
34、ngly on a bench top or clip to a line. Waitan appropriate amount of time prior to making test measure-ments, for example, 15 to 30 min. for initial densitometric orspectrophotometric evaluations, 72 h for chemical resistancetests.9.18 For letterpress printing, follow the procedure for dryoffest prin
35、ting with the following exceptions: In 9.3, tape orotherwise mount the substrate on the blanket cylinder, not onthe impression plate. Skip 9.1-9.12.In9.13, roll the blanketcylinder containing the substrate over the inked printing plateand then stop.NOTE 3For heat-set inks, apply heat or run through
36、the heat set testerin accordance with Test Method D6073. Energy-curable ink prints shouldbe passed through a UV lamp curing unit or other appropriate apparatus.10. Instrumental Verification of Reflection Density10.1 If the print is black, white, or a process color, use adensitometer with the appropr
37、iate filter. Otherwise, use a colorspectrophotometer. After the print has dried to the touch (15 to30 min), make five measurements, one in each corner 25 mm(1 in.) from each edge and one in the center, and compute themean.10.2 A small decrease in reflection density may occur onabsorbent substrates b
38、etween the initial measurements takenafter prints were made and those taken 24 h later due to dryback with some types of printing inks. This density decreaseshould be accounted for so that the final dry average densitymatches the target reflection density.10.3 When comparing results between laborato
39、ries, densi-tometers must be calibrated using the same aperture size, filter,band width, etc., and a certified reference material such as theT-Ref standard.11. Keywords11.1 dry offset proofing; letterset proofing; paste printinginks; printing inks; proofing of inksANNEX(Mandatory Information)A1. SET
40、TING UP THE PROOF PRESSA1.1 Tighten blanket to 8.13 Nm (6-in.) using a torquescrew driver. (Fig. A1.1)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
41、bed to maintain plate position.A1.3 Mark each guide track “Far” or “Near” 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 meta
42、lshims under the impression plate.A1.5 For older presses (models having a crank-handledrive), adjust height and level of printing and impression platesto produce uniform print in the following manner:A1.5.1 Hand tighten screw on printing plate and positionguide tracks against plate.A1.5.2 Clean all
43、surfaces with appropriate solvent andlint-free rags or tissues.A1.5.3 Apply 0.6 mL or 0.6 g of ink to the brayer uniformlydirectly from the pipet or with an ink knife.FIG. A1.1 Laboratory Flat-Bed Press Equipped with Push Handle, Set Up for Dry Offset ProofingD6487 103A1.5.4 Roll out the ink on the
44、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, roll brayer diagonally from corner to corner ofthe ink distribution plate to make a single “X” pattern. Thenmove brayer from top to b
45、ottom 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 diagonally from corner to corner of the ink distributionplate to make a single “X” pattern. Then move brayer from topto bottom and bottom
46、 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 is motion in one directiononly, left to right or right to left). Do not lift brayer betweenpasses. Pressure applied will depend on th
47、e 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 blanket cylinder by turning handle on topof carriage counter clockwise to the stop position.A1.5.8 Roll blanket cylinder to a position
48、 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.A1.5.1
49、0 Disengage blanket cylinder and roll ahead to posi-tion 12 mm (12 in.) before trailing edge of printing plate.Engage cylinder and make a stripe as in A1.5.8 and A1.5.9.A1.5.11 Measure the width of each stripe on the far and nearside of the printing plate (a total of four measurements). Properpress set up requires that both stripes have a constant width of8mm(516 in.).A1.5.12 If the stripes are not consistent, add shims under theprinting plate. After each adjustment, clean the printing plateand blanket and reapply ink to the plate as described inA1.5.4-A1.5.6. I
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