1、Designation: F 1721 04Standard Practices forDetermining Stability of Direct Thermal Imaging Products1This standard is issued under the fixed designation F 1721; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revis
2、ion. 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 These practices cover the evaluation of the effect ofvarious solvents, light, heat, and humidity on direct thermalimaging produ
3、cts.1.2 These practices may be used to evaluate the perfor-mance of thermal products coated on paper, film, or othersubstrate for specific applications.1.3 These practices may be used for manufacturing control,development, and research.1.4 The sections in these practices appear in the followingseque
4、nce:Scope 1Referenced Documents 2Terminology 3PracticesSolvent Resistance 411Light Stability 1218Heat and Humidity Stability 1925Keywords 261.5 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 t
5、o establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2D 2244 Test Method for Calculation of Color Differencesfrom Instrumentally Measured ColorF 767 Test Method for Image Stability of Ch
6、emical Carbon-less Paper to LightF 1320 Test Method for Evaluating Thermal Paper Employ-ing a Facsimile Thermal Printer as a Test InstrumentF 1405 Test Method for Determining the Dynamic ThermalResponse of Direct Thermal Imaging ProductsAtlantekMethodF 1444 Test Method for Determining the Dynamic Th
7、ermalResponse of Direct Thermal PaperLabel Printer Method2.2 ANSI Standard:ANSI/CGATS 4-1993 Graphic TechnologyGraphic ArtsReflection Densitometry MeasurementsTerminology,Equations, Image Elements and Procedures33. Terminology3.1 Definition:3.1.1 direct thermal imaging product, npaper, film, orother
8、 substrate upon which a coating is applied; the imagingcomponents consist of a color former (leuco dye), a developer,a sensitizer, and antioxidants which react to form an imagewhen sufficiently heated from a thermal printhead.SOLVENT RESISTANCE4. Summary of Practice4.1 Select one or more of the solv
9、ents appropriate to theapplication for which the product will be used.4.2 Imaged samples including a control are measured foroptical density then subjected to contact by various solventmaterials for a specified time. Optionally, L*,a*,b* values canbe measured for the background using a spectrodensit
10、ometer.After the test time is completed, the samples are againmeasured for optical density and L*,a*,b* and compared to acontrol. The L*,a*,b* measurements will indicate changes inimage color.4.2.1 Most units which measure L*,a*,b* can provide thedifference values in the form of DL*, Da*, Db* and DE
11、. Referto the technical literature on color measurement for theinterpretation of these results.5. Significance and Use5.1 These procedures enable comparison of samples with acontrol under various solvent conditions to determine thestability of the image. The various solvents simulate conditionswhich
12、 may be encountered in the environment.5.2 The test may be used to judge which materials aresuitable for a specific situation and usage. The sensitivity of theproducts should match and the products should be for the sameapplication.1These practices are under the jurisdiction of ASTM Committee F05 on
13、Business Imaging Products and are the direct responsibility of SubcommitteeF05.06 on Carbonless and Thermal Imaging Products.Current edition approved Feb. 1, 2004. Published April 2004. Originallyapproved in 1996. Last previous edition approved in 1996 as F 172196.2For referenced ASTM standards, vis
14、it the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.3Available from American National Standards Institute, 25 W. 43rd St., 4thFloor, New York, NY 10
15、036.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.5.3 The procedure may be used for the evaluation of directimaging coatings on paper, film, or other substrate. The methodof imaging should be with the type of imaging unit for which
16、the product has been designed.6. Interferences6.1 Backing material will affect the reading taken with aspectrodensitometer. Specify which backing is used whentaking a reading.6.2 When reading L*,a*,b* values, also record observer,illuminator, and geometry of the instrument.7. Apparatus and Materials
17、7.1 Spectrodensitometer, with an aperture smaller than theimage area to be measured and meeting the requirements ofANSI/CGATS 4-1993, operating in visual density mode.7.2 Oven, operated at 100 6 4F (38 6 2C).7.3 Printer or Alternative Imaging Device.7.4 Weight2.5 lb/in.2(0.176 kg/cm2).7.5 PVC Film.7
18、.6 Cottonseed Oil.7.7 Castor Oil.7.8 Saturated Salt Solution.7.9 Ethyl Alcohol, 20 % v/v water, denatured.7.10 Isopropyl Alcohol.7.11 Pipette.7.12 OptionInstrument for the measurement of L*,a*,b*.8. Test Specimens8.1 The test specimens and control shall be sheets or takenfrom a roll of direct therma
19、l imaging product.8.2 Cut samples into individual sheets approximately 812 by11 in. (216 by 279 mm). A maximum of six sheets per sampleare required for testing.8.3 Employ a control sample whose characteristics havebeen previously established or to which all results will becompared.9. Calibration9.1
20、SpectrodensitometerCalibrate the densitometer in ac-cordance with the manufacturers recommendations.9.2 OptionL*,a*,b* InstrumentCalibrate the unit inaccordance with the manufacturers recommendations.10. Procedure10.1 Image the samples and control with a printer to providea series of images. Imaging
21、 may be achieved with a facsimilethermal printer employing a suitable test target (see TestMethod F 1320) or by imaging systems described in TestMethods F 1405 or F 1444. If possible, have some images be asolid block at least14 by14 in. (0.6 by 0.6 cm). Image allsamples in the same manner.10.2 Using
22、 the reflectance spectrodensitometer, measure theimage density of the samples and control after full densitydevelopment. Optionally, L*,a*,b* values may be measuredfor the background. A minimum of five measurements shouldbe taken and averaged to improve accuracy. Measurementsshould be made in the sa
23、me relative location on each sample.10.3 Wrap each imaged sample and imaged control withthree layers of PVC film, taking care to keep the samples flatand the film wrap wrinkle free. Place samples in an ovenestablished at 100 6 4F (386 2C) under a weight of 2.5lb/in.2for 16 h.10.4 Coat an imaged samp
24、le and imaged control withcottonseed oil or castor oil and place in an oven established at100 6 4F (38 6 2C) for 16 h. Use a pipet or similar deviceto ensure that an equivalent amount of oil is applied to eachsample.10.5 Immerse imaged sample and imaged control in waterfor 16 h at room temperature.
25、Upon removal, absorb excesswater with paper toweling and allow samples and control to airdry at room temperature.10.6 Immerse imaged sample and imaged control in asaturated sodium chloride salt solution for one hour at roomtemperature. Upon removal, absorb excess moisture with papertoweling and allo
26、w the samples to air dry at room temperature.10.7 Immerse imaged sample and imaged control in ethylalcohol (20 %, denatured) for1hatroom temperature. Uponremoval, blot excess solvent and allow the samples to air dry atroom temperature.10.8 Measure the optical density and L*,a*,b* of theimaged sample
27、s and the imaged control samples from 10.3 to10.7. Measure the same locations as originally measured in10.2. Most L*,a*,b* units will permit the measurement of thechange in color (4.2.1).10.9 Wipe an imaged sample and imaged control with aswab dampened with isopropyl alcohol. Visually compare theima
28、ge of the sample to the control.10.10 Compare the results of the samples to the control andestablish a ranking order.11. Report11.1 Report the following information:11.1.1 Dates that the test was conducted.11.1.2 Sample and control identification.11.1.3 Information regarding the equipment and materi
29、alsemployed in the tests.11.1.4 Method used to image the samples.11.1.5 Results of the individual tests including the numberof readings taken on each sample; the high, low, and average ofthe optical density and L*,a*,b* before and after each test;and relative results compared to the control.11.1.6 A
30、ny additional information regarding the test, thesamples, or the test conditions.LIGHT STABILITY12. Summary of Practice12.1 Samples and control are imaged on an appropriateprinter. Background and image densities are measured with aspectrodensitometer. Optionally, L*,a*,b* values can bemeasured for t
31、he background and images using a colorimeteror spectrodensitometer. Samples and control are placed in a5000-lux light chamber for 100 h. A longer time can be chosendepending on stability requirements. The minimum exposuretime shall be long enough to allow differentiation betweenimages that have acce
32、ptable stability and those that have poorF1721042stability. Following exposure, the background, and imagedensities, or optionally L*,a*,b*, are remeasured and com-pared to the original values. The L*,a*,b* measurements willindicate changes in color.12.1.1 Most instruments that measure L*,a*,b* can p
33、ro-vide the difference values in the form of DL*, Da*, Db* andDE. Refer to Test Method D 2244 for calculation of colordifferences based on instrumentally measured color coordi-nates.12.2 This practice can be used for the evaluation of directimaging coatings on paper, film, or other substrate. The me
34、thodof imaging should be with the type of imaging unit for whichthe product has been designed.13. Significance and Use13.1 This practice enables comparison of samples with acontrol under accelerated light conditions to determine thestability of the image and the background.14. Apparatus14.1 Spectrod
35、ensitometer, with an aperture smaller than theimage area to be measured and meeting the requirements ofANSI/CGATS 4-1993, operating in visual density mode.14.2 Cool White Fluorescent Lamp Light Boxdescribed inTest Method F 767 and operated to provide 5000 lux of totalradiation on the sample surface
36、or alternate equipment such asan exposure device that uses xenon arc radiation filtered tosimulate solar radiation through window glass. Test results maydiffer between laboratories, particularly when different types ofequipment are used, and will require comparative testing todetermine exposure time
37、s to produce equivalent test results.14.3 OptionInstrument for the measurement of L*,a*,b*.15. Test Specimens15.1 The test specimens and control shall be sheets or takenfrom a roll of direct thermal product.15.2 Cut samples into individual sheets approximately 812by 11 in. (216 by 279 mm).15.3 Emplo
38、y a control sample whose characteristics havebeen previously established or to which all results will becompared.16. Calibration16.1 SpectrodensitometerCalibrate the densitometer inaccordance with the manufacturers recommendations.16.2 OptionL*,a*,b* InstrumentCalibrate the unit inaccordance with th
39、e manufacturers recommendations.17. Procedure17.1 Image the samples and control with a printer to providea series of images. Imaging may be achieved with a facsimilethermal printer employing a suitable test target (see TestMethod F 1320) or by units described in Test Methods F 1405or F 1444. If poss
40、ible, have some images be a solid block atleast14 by14 in. (0.6 by 0.6 cm). Image all samples in the samemanner.17.2 Using the reflectance spectrodensitometer, measure thebackground and image densities of the samples and controlafter full density development. A minimum of five measure-ments shall be
41、 taken and averaged to improve accuracy.Measurements shall be made in the same relative location oneach sample.17.3 Option: Using the L*,a*,b* instrument, measure thebackground and image colors of the samples and the control. Aminimum of five measurements shall be taken and averaged toimprove accura
42、cy. Measurements shall be made in the samerelative location on each sample.17.4 Place the samples in a 5000-lx light chamber for 100 h.Caution must be taken to ensure that the samples are main-tained at constant temperature below 30C to avoid anypotential results from heat aging.NOTE 1A longer expos
43、ure time can be employed depending on thestability requirements of the application.17.5 After exposure, remeasure the image and backgrounddensities, or color (L*,a*,b*) of each in both the samples andcontrol using the same areas as used in 17.2 and 17.3.17.6 Compare the results for the samples and c
44、ontrol withmeasurements of the background and image obtained prior toexposure. Most L*,a*,b* instruments will provide data on thechange in color (12.1.1).18. Report18.1 Report the following information:18.1.1 Dates that the test was conducted.18.1.2 Sample and control identification.18.1.3 Informati
45、on regarding the equipment employed inthe tests.18.1.4 Method used to image the samples.18.1.5 Initial and final results of the individual tests includ-ing the number of measurements made on each sample; thehigh, low, and average readings; and relative results comparedto the control.18.1.6 Any addit
46、ional information regarding the test, thesamples, or the test conditions.HEAT AND HUMIDITY STABILITY19. Summary of Practice19.1 This practice employs samples that have been imagedand unimaged. Samples and control are imaged using anappropriate printer. Background and image density of eachsample are
47、measured and recorded. Optionally, L*,a*,b*values can be measured for the background using a spectroden-sitometer. Part of the samples are placed in a 140 6 4F (6062C) laboratory oven for 24 h. The other samples are placed ina temperature humidity chamber maintained at 104 6 4F (406 2C) and 90 6 5 %
48、 relative humidity for 14 days. At the endof the exposure time the background, image densities, and L*,a*,b* of the samples are reread and compared to the control.The L*,a*,b* measurements will indicate changes in imagecolor.19.1.1 Most units which measure L*,a*,b* can provide thedifference values i
49、n the form of DL*, Da*, Db* and DE. Referto the technical literature on color measurement for theinterpretation of these results.19.2 This practice can be used for the evaluation of directimaging coatings on paper, film, or other substrate. The methodF1721043of imaging should be with the type of imaging unit for whichthe product has been designed.20. Significance and Use20.1 This practice enables comparison of samples with acontrol under accelerated aging conditions to determine thestability of the background, imaged and unimaged product toheat
