1、Designation: F 1444 00 (Reapproved 2004)Standard Test Method forDetermining Dynamic Thermal Response of Direct ThermalPaper-Label Printer Method1This standard is issued under the fixed designation F 1444; the number immediately following the designation indicates the year oforiginal adoption or, in
2、the case of revision, 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. Scope1.1 This test method covers the thermal response of directthermal papers to determine u
3、niformity within and betweenlots. This test method may also be used to test direct thermalproducts other than paper.1.2 The Hobart 18VP Thermal Label Printer2described inthis test method may be used for specification acceptance,product development or research applications, or both, andmanufacturing
4、control.1.3 Although a specific manufacturer has been identified forthis equipment, any thermal label printer with equivalent signaloutput capabilities and sample size requirements would besuitable.1.4 The values stated in inch-pound units are to be regardedas the standard. The SI units given in par
5、entheses, are forinformation only.1.5 This standard does not purport to address all of thesafety concerns, if 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 limita
6、tions prior to use. (WarningThistest method requires making power adjustments and triggerprinting while the protective cover is off, thereby exposing theuser to electrical hazards.)2. Referenced Document2.1 ANSI Standards:3IT 2.161995IT 2.1719953. Terminology3.1 Definitions of Terms Specific to This
7、 Standard:3.1.1 dynamic thermal response curvethe graphical rep-resentation of the response characteristic of a thermal printingsystem over a given range of print energies. The y-axis of thegraph is optical density (reflectance density), while the x-axis iscalibrated in terms of print energy or ener
8、gy density. Typicalunits for print energy are watts/dot or millijoules (mj), whereasthe units for print density are millijoules per square millimetre,mj/mm2.3.1.2 dynamic thermal sensitivitythe generation of thethermal response of thermal paper within a given printingsystem over a specific operating
9、 range of energy levels.4. Summary of Practice4.1 This practice is intended to determine the dynamicthermal sensitivity of direct thermal papers. The energy versusimage density relationship obtained is a characterization of agiven coating and base paper. Curves can be used to determineuniformity wit
10、hin and between direct thermal paper lots. Thetest equipment and test procedures are not intended to simulatethermal response under actual end use conditions in a facsimilemachine.4.2 To determine the dynamic thermal sensitivity of directthermal facsimile, chart, or label papers, a 2.5 in. (6.35 cm)
11、wide sample is fed into the printer (minimum 11 in. (27.94 cm)length is suggested).4.3 A voltage controller on the power board allows theadjustment of the power to the thermal head (watts per dot).Voltage squared is a function of energy usually expressed inwatts/dot or millijoules (mj).4.4 The therm
12、al response or density saturation curve can beobtained by generating one of six available label patterns ontest samples using a range of energy levels.5. Significance and Use5.1 This test method enables dynamic thermal responsecomparisons between direct thermal papers.5.2 This test method makes comp
13、arisons between andwithin thermal paper production lots from the same manufac-turer.1This test method is under the jurisdiction ofASTM Committee F05 on BusinessImaging Products and is the direct responsibility of Subcommittee F05.06 onCarbonless and Thermal Imaging Products.Current edition approved
14、Dec. 1, 2004. Published December 2004. Originallyapproved in 1992. Last previous edition approved in 2000 as F 1444 00.2The sole source of supply of the apparatus known to the committee at this timeis Hobart Canada Inc., Don Mills, Ontario, M3A 1B1 If you are aware ofalternative suppliers, please pr
15、ovide this information to ASTM InternationalHeadquarters. Your comments will receive careful consideration at a meeting of theresponsible technical committee1, which you may attend.3Available from American National Standards Institute, 25 West 43rd St., 4thFloor, New York, NY 10036.1Copyright ASTM I
16、nternational, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.6. Interferences6.1 Wide variations in environmental conditions(temperature/RH) could impact the image density obtainedwith the use of this test method.6.2 The length of elapsed time following imaging a
17、ndsubsequent image density measurements should be controlled.For best results, density measurements should be made within5 min of imaging. The exact time selected should remainconstant for all samples to be compared.6.3 Since the thermal facsimile papers are sensitive toprolonged exposure to light,
18、samples should be covered orotherwise protected prior to actual image testing. Excessiveexposure to light can affect final test results.6.4 Since differences in the basis weight and stiffness mayhave a significant effect on the results, comparisons should bemade between materials with similar physic
19、al properties.6.5 This test method does not predict performance inthermal printers but characterizes the coating sensitivity.6.6 Any residue or coating buildup on the printhead resistorelements (dots) may result in inaccurate test values and reduceprinthead life.7. Apparatus and Materials7.1 Hobart
20、18VP Thermal Label Printer.27.2 Electrical Wire and Electrical Insulated Box, to movepower supply voltage test point outside the printer housing.7.3 Digital Display Multimeter.7.4 Macbeth Model RD-517 Densitometer, or equivalent.8. Sampling, Test Specimens, and Test Units8.1 The test specimen shall
21、be a sheet or roll of thermalproduct handled only by their edges prior to testing.8.2 Samples should be cut into individual strips 2.5 in. (6.35cm) wide with a recommended minimum length of 11 in.(27.94 cm). At least ten sample strips will be needed for eachcurve generated.9. Calibration9.1 In calib
22、rating the test instrument, the use of solid areadensity control charts using specific power settings and thermalproduct with a known sensitivity level has been found to be thebest calibration method.9.2 Calibrate the densitometer according to manufacturersinstructions.10. Conditioning10.1 Although
23、no special conditioning of thermal papersamples is required, it would be prudent to compare only testsrun under the same environmental and aging conditions.11. Procedure11.1 Establishing the Voltage Test Points:11.1.1 Be sure the printer is unplugged, before opening theprinter cover. Connect test le
24、ads to the backside of the logicboard 1J5 connector at 1J5-1 ( + ) and 1J5-10 () points. Usinginsulated wire, bring the leads to an insulated electrical boxsuitable for multimeter lead connections.11.1.2 If the resistance value is not visible, the thermal headmay be removed from the printer. Followi
25、ng equipment manu-facturers instructions remove the thermal head and record thestamped resistance value (see Fig. 1). Reinstall the thermalhead following equipment manufacturers instructions.11.1.2.1 With the thermal head resistance value (V), calcu-late the voltages for the various watts/dot levels
26、 using thefollowing formula:voltage 5 =watts/dot! 3 resistance of head! 1 1.5 V (1)The number of test points required may vary but a minimumof ten ranging from 0.3 to 1.8 W/dot is recommended as astarting range. These calculations need only be made once fora given printhead. Table 1 shows a typical
27、table of test points.11.1.3 Load the test sample into the printer following theloading instructions listed on the inside cover of the printer.11.1.4 With the power on, and the multimeter attached tothe test leads, adjust the voltage to the highest calculated testpoint using the control pot on the po
28、wer supply board. Be sureto use a nonconducting alignment tool to adjust the voltagepotentiometer to avoid shorting out components on the powerboard. The potentiometer is located in the center of the printerpower supply board (see Fig. 2). Thermal head supply voltagelevels which exceed manufacturers
29、 recommended maximumlevel on the thermal head may shorten its life.11.1.5 Trigger the diagnostic switch (SW1) on the printerlogic board to print a test pattern. If a test pattern is not printedafter the second time the trigger is hit, the label detection pot(1J2) on the printer logic board may have
30、to be adjusted untila print is obtained (see Fig. 2). Although program switches onthe logic board allow the user to obtain six different testpatterns, all contain the six square blocks used to create thedensity curves (see Fig. 3).11.2 Generating the Thermal Response Curves:11.2.1 It is recommended
31、that at least three test prints oneach paper be run at each voltage setting. This will giveeighteen density blocks per paper type per voltage setting.Record one density reading on each of the six density blocksfor each of the three test patterns.11.2.2 Plot the average of the eighteen readings on gr
32、aphpaper with watts per dot on the “x-axis” and density on the“y-axis” (see Fig. 4 and ANSI IT2.16 and IT2.17.).FIG. 1 Hobart 18VP Thermal Printer,2Thermal HeadF 1444 00 (2004)211.2.3 Change the voltage setting, run another series ofsamples, read the density and plot the average density valueagainst
33、 the watts/dot.11.2.4 Repeat 11.2.1-11.2.3 for each test sample.11.2.5 A minimum of ten different test points (voltagelevels) should be used for density curve generation. However,additional points will better define the curve in the criticalregion, that region in which small increases in head temper
34、a-ture result in significant image density increases.12. Report12.1 Report the following information:12.1.1 Sample Identification:12.1.1.1 Coated roll batch or lot number,12.1.1.2 Manufacturer and product code,12.1.1.3 Date or time of manufacture, or both, if available,and12.1.1.4 The voltage determ
35、ined in 11.1.2.1. The exposuretime is established by the traversing mechanism of the printerand is not adjustable.12.1.2 Report the temperature and humidity of the ambienttest conditions.12.1.3 Report the density data obtained in tabular form or ascurves such as those shown in Fig. 4.12.1.4 The dens
36、ity versus watts/dot curves generated by thetest samples may be compared with the rate at which they reachsaturation (maximum density), the maximum density obtainedand the watts per dot at which the density starts to drop off.13. Precision and Bias13.1 Repeatable measurements on the same paper and s
37、ametest equipment should agree within 6 2 % of density for allpoints on the thermal response curve. This precision and biasstatement is based on the equipment listed in theApparatus andMaterials section of this test method.13.2 Measurements between laboratories may not be repro-ducible because of di
38、fferent test equipment and testers. ATABLE 1 Hobart Thermal Tester,2Watts/Dot to VoltageComparisonNOTE 1Resistance (V) will be stated on the thermal head. The 1.5 Vis the line loses from the voltage test points to the thermal head.Watts/Dot Voltage1.8 17.031.6 16.141.4 15.201.2 14.181.0 13.080.8 11.
39、850.7 11.190.6 10.470.5 9.690.4 8.820.3 7.84voltage 5 = watts/dot! 3 resistance of head! 1 1.5 Vhead resistance 5 134 VFIG. 2 Hobart 18VP Thermal Printer,2Circuit BoardsFIG. 3 Hobart 18VP Thermal Printer,2Diagnostic Test PatternF 1444 00 (2004)3laboratory correlation test may be used to minimize dif
40、ferencesbetween test equipment and establish a correlation betweenlaboratories.13.3 The precision of this test method is dependent upon theskill or experience of the operator, or both.13.4 The precision of this test method is not affected,provided that:13.4.1 The same test equipment is used,13.4.2 C
41、alibration procedures and frequency of calibrationare the same,13.4.3 The proper sample loading procedure is used, and13.4.4 Ambient conditions are similar.14. Keywords14.1 direct thermal paper; dynamic thermal response; dy-namic thermal response curve; thermal printer; thermal sensi-tivityASTM Inte
42、rnational 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
43、 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 reapproved or withdrawn. Your comments are invited either for revision of this standard or for additional standardsand sho
44、uld 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 Committee on Sta
45、ndards, 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).FIG. 4 Dynamic Thermal Response CurveF 1444 00 (2004)4
