ASTM_F_1536_-_95_2015.pdf

Designation:F153695(Reapproved 2015)Standard Test Method forDetermining Strength and Setting Time of Synthetic Water-Activated Polyurethane Fiberglass Orthopaedic CastingTape1This standard is issued under the fixed designation F1536;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()indicates an editorial change since the last revision or reapproval.1.Scope1.1 This test method covers the functional diametral com-pression strength of cylindrical test specimens formed fromsynthetic fiberglass polyurethane casting materials.The testspecimens employed in this test method are similar in geom-etry and construction to casts used in orthopaedic applications.This test method is not intended to determine the strength ofthe base materials used for fabrication of the test specimen.1.2 The values stated in inch-pound units are to be regardedas standard.The values given in parentheses are mathematicalconversions to SI units that are provided for information onlyand are not considered standard.1.3 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.Specific warningstatements are given in 6.7.2.Referenced Documents2.1 ASTM Standards:2E4 Practices for Force Verification of Testing MachinesE691 Practice for Conducting an Interlaboratory Study toDetermine the Precision of a Test Method3.Terminology3.1 Definitions of Terms Specific to This Standard:3.1.1 diametral compression strengththe load per unitwidth in lbs/in.(Newtons/mm),calculated by dividing eitherthe peak failure load or the maximum deflection load by thenominal sample length(that is,manufacturers stated tapewidth).3.1.2 maximum deflection loadthe test cylinder is com-pressed 0.4 in.(10 mm)from the initial load position withoutnoticeable failure or a measurable decrease in load.The load at0.4 in.(10 mm)deflection shall be called the maximumdeflection load.3.1.3 peak failure loadfailure of the test cylinder with aconcomitant decrease in load prior to 0.4 in.(10 mm)diametralcompression.The highest load attained prior to the decreaseshall be called the peak failure load.4.Summary of Test Method4.1 Atest cylinder is prepared by immersing the casting tapein 75 6 2F(23.9 6 1.1C)water,squeezing per themanufacturers instructions under the surface of the water,andthen wrapping around either a 2.0 in.(50.8 mm)or 2.5 in.(63.5mm)outside diameter cylindrical mandrel.The tape is wrappedlayer upon layer producing a five layer cylinder.The testcylinder is removed from the mandrel after an initial settingperiod.After a specified time,the test specimen is positionedon its side between two flat platens in the testing machine andcompressed to determine its strength.Ambient temperature andhumidity are specified because of their pronounced effect onmaterial properties during the curing period.5.Significance and Use5.1 Diametral compression strength is an important measureof the mechanical properties of casting materials.This testmethod simulates the loading pattern seen in lower extremitycasting applications during ambulation.This test method can-not be used to determine cast life or measure bending or othermodes of cast failure.5.2 This test method measures but does not prescribe values.6.Apparatus6.1 Testing MachinesMachines used for compression test-ing shall conform to the requirements of Practices E4.Foruniversal machines with a common test space,calibration shallbe performed in compression.1This test method is under the jurisdiction ofASTM Committee F04 on Medicaland Surgical Materials and Devices and is the direct responsibility of SubcommitteeF04.15 on Material Test Methods.Current edition approved May 1,2015.Published July 2015.Originally approvedin 1995.Last previous edition approved in 2010 as F1536 95(2010).DOI:10.1520/F1536-95R15.2For referenced ASTM standards,visit 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.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 6.1.1 The surfaces of the flat platens shall be perpendicularto the loading axis and parallel at all times within 0.005 in./in.(1.3 mm/mm).Platen surfaces should be clean and free ofcorrosion.6.1.2 The testing machine shall be capable of producing aconstant compression rate between 1 to 10 in./min(25.4 to 254mm/min).6.1.3 The testing machine shall be capable of measuring thecompressive load within 60.5 lbs(2.2 N).6.2 Test Specimen Preparation MandrelA solid,cylindri-cal aluminum mandrel of sufficient length to accommoda