ASTM_F_1444_-_00.pdf

Designation:F 1444 00Standard 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 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 uniformity 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 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 parentheses,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 limitations prior to use.NOTE1WarningThis test method requires making power adjust-ments and trigger printing while the protective cover is off,therebyexposing the user to electrical hazards.2.Referenced Document2.1ANSI Standards:3IT 2.161995IT 2.1719953.Terminology3.1 Definitions of Terms Specific to This 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 energy 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 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 within 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)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 thermal 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 comparisons between andwithin thermal paper production lots from the same manufac-turer.6.Interferences6.1 Widevariationsinenvironmentalconditions(temperature/RH)could impact the image density obtainedwith the use of this test method.6.2 The length of elapsed time following imaging andsubsequent image density measurements should be controlled.For best results,density measurements should be made within5 min of imaging.The exact time selected should remain1This test method is under the jurisdiction ofASTM Committee F-5 on BusinessImaging Products and is the direct responsibility of Subcommittee F05.06 onCarbonless Copy Paper.Current edition approved June 10,2000.Published August 2000.Originallypublished as F 1444-92.Last previous edition F 1444-92(1996).2Manufactured by Hobart Canada Inc.,Don Mills,Ontario,M3A 1B1.3Available from American National Standards Institute,11 West 42nd St.,NewYork,NY 10036.1Copyright ASTM,100 Barr Harbor Drive,West Conshohocken,PA 19428-2959,United States.constant for all samples to be compared.6.3 Since the thermal facsimile papers are sensitive toprolonged exposure to light,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 physical properties.6.5 This test method does n