1、Designation: F1536 95 (Reapproved 2015)1Standard 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
2、 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.1NOTEEditorial corrections were made in June 2016.1. Scope1.1 T
3、his 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
4、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 only
5、and 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 limitati
6、ons 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 Speci
7、fic 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 cylin
8、der 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
9、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 sur
10、face 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, th
11、e 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 compre
12、ssion 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 failu
13、re.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. For1This test method is under the jurisdiction of ASTM Committee F04 on Medicaland Surgical Materials and Devices a
14、nd 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/F1536-95R15E01.2For referenced ASTM standards, visit the ASTM w
15、ebsite, 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 St
16、ates1universal machines with a common test space, calibration shallbe performed in compression.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 te
17、sting 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 suffic
18、ient length to accommodatethree test specimens without end contact shall be mounted in ahorizontal position (see Fig. 1). Either of two mandrel diam-eters may be used: Type I2.00 in. (50.8 mm) diameter, orType II2.50 in. (63.5 mm) diameter.6.2.1 OptionThree individual mandrels, either Type I orType
19、II, each capable of holding one test specimen, may besubstituted for a single, solid mandrel.6.3 Constant Tension MethodEach layer of tape shall bewrapped on the mandrel at a constant tension of 0.25 lbs/in.(4.5 g/mm) width of tape. Suggested methods for accomplish-ing this include the use of a dead
20、 weight clamped to the freeend of the tape while the horizontally mounted mandrel ismanually rotated (see Fig. 1), or the use of an automatedconstant torque winding mechanism (see Fig. 2).6.4 Water ContainerA container capable of holding atleast 1 gal (3.78 L) of water and of sufficient depth to all
21、owcomplete immersion of the casting tape.6.5 Release LinerA sheet form liner of nominal thickness,such as waxed paper, shall be used to cover the mandrel andprevent adhesion of the resin to the mandrel. The liner shallallow release of the cured specimen from the mandrel withminimal force, and shall
22、be easily removable from the speci-men inner diameter prior to compression testing.6.6 TimerA timing device accurate to 61s.6.7 GlovesGloves capable of protecting the hands fromcontact with the resin, for example, latex surgical gloves.(WarningContact with uncured or curing resins should beavoided.
23、These resins may adhere to the skin and be difficult toremove. In addition, most polyurethane resins contain isocya-nate to which some individuals are or may become sensitized.Gloves should be worn at all times when handling uncured orcuring casting tape.)FIG. 1 Manual Preparation MethodF1536 95 (20
24、15)126.8 ThermometerAdevice capable of measuring tempera-tures within 61F (0.5C) in the 70 to 80F (21.1 to 26.7C)range.7. Reagents and Materials7.1 At least three rolls of the casting tape shall be tested; oneroll for each of the three specified time periods. Three testcylinders shall be prepared fr
25、om each roll without the use ofmanual molding techniques.NOTE 1If testing of cylinders with the use of manual molding isdesired, a secondary group of samples should be prepared using thedesired molding technique.7.2 Water for initiation of the curing process shall bemaintained at 75 6 2F (23.9 6 1.1
26、C).7.2.1 The water shall be changed after three rolls have beenprepared.8. Sample Conditioning8.1 Store each package flat, with each roll on its side, at 706 5F (21.1 6 2.8C) for at least 24 h before use.8.2 Open each package immediately prior to use.9. Specimen Preparation9.1 Before opening each pa
27、ckage, record the manufacturersname, product description, size (width and length), and lotnumber.9.2 Wrap the release liner around the test specimen prepa-ration mandrel and secure with tape.9.3 Open the package and loosely grasp roll with coreperpendicular to fingers in palm of hand.9.4 Start the t
28、imer, fully immerse roll in water and squeezefollowing manufacturers instructions. Record immersion timeand number of squeezes.9.5 Remove the roll from the water and allow excess waterto drain for not more than five seconds. DO NOT SQUEEZEto remove excess water.9.6 Wrap a five-ply cylinder on the ma
29、ndrel as rapidly aspossible using constant tension (see Fig. 1 or Fig. 2). Eachsucceeding layer shall be aligned directly over the precedinglayer with complete overlap. Cut the tape at the end of the fifthply within 614 in. (6.4 mm) relative to the starting end of thefirst ply.9.7 Immediately wrap a
30、 second five-ply cylinder as rapidlyas possible by repeating 9.6.9.8 Immediately wrap a third five-ply cylinder as rapidly aspossible by repeating 9.6. Cut off excess tape.9.9 MoldingPrimary test samples should be preparedwithout the use of manual molding. If testing of samples withthe use of manual
31、 molding is desired, a secondary group ofsamples should be prepared using the desired molding tech-nique. Record the molding time and degree of manipulationused.9.10 Setting TimeThis is determined by a manual inden-tation test, that is, the time elapsed from the initial immersionuntil the test cylin
32、der cannot be indented by moderate finger-nail pressure. Begin indentation testing for material settingafter all three samples from a single roll are wrapped. Repeatthe test every 15 s until all samples are set. Record the threetimes and report the average as the setting time.9.11 After the test cyl
33、inders have set, remove them from themandrel taking care to avoid deforming them. Remove therelease liner from the inside of the test cylinders.9.12 Stand test specimens on end with enough space be-tween samples to allow air to freely circulate between thecylinders.10. Procedure10.1 Testing SpeedThe
34、 recommended constant crosshead(or actuator) speed shall be between 1 to 10 in./min (25.4 to254 mm/min). Report the exact speed.NOTE 2Testing speeds outside the recommended range may be usedprovided that there are no demonstrable rate-dependent effects on theFIG. 2 Automated Constant Torque Preparat
35、ion MethodF1536 95 (2015)13material and that complete data capture is assured at higher rates.10.2 Load Range SelectionSet the load range of thetesting machine so that the maximum expected load is at least20 % of the range selected.10.3 Thirty Minute Diametral Compression StrengthThistest is perform
36、ed 30 6 5 min after the time of initial immersionof the sample roll.10.3.1 Place each specimen, one at a time, between theplatens of the testing machine. Center the test cylinder on thelower platen, the platen being sufficiently large to support thespecimen over its entire length. Orient the test cy
37、linder so thatthe transition or overlap area, that is, where the first ply beginsand the fifth ply ends, is in contact with either the upper orlower platen.NOTE 3The presence or absence of an overlap between the first andfifth ply affects the strength of the transition area, by either increasing ord
38、ecreasing it from that of the surrounding area with a uniform number ofplies. Since sample failure generally occurs in regions of high tensilestress on the free outer wall of the test cylinder, it is important that theoverlap, or transition area, not be in the high tensile stress region.10.3.2 Bring
39、 the platens together until they just touch thetest cylinder, but no load has been applied.10.3.3 Initiate the test at the prescribed rate. Continue thetest at a uniform rate until the one of the following conditionsoccurs: either cylinder failure occurs or the maximum deflec-tion is reached.10.3.4
40、If the test cylinder has not set in 30 min, do not testfor the 30 min diametral compression strength.10.3.5 Record for each cylinder the maximum reading inpounds (Newtons), that is, the peak failure load or themaximum deflection load, whichever occurs first. The 30 mindiametral compression strength
41、is the average of the threevalues calculated from the readings.10.4 Sixty Minute Diametral Compression StrengthThistest is identical to the 30 min diametral compression test and isperformed 60 6 5 min after the time of initial immersion of thesample roll.10.5 Twenty-Four Hour Diametral Compression S
42、trengthThis test is identical to the 30 and 60 min diametral compres-sion tests and is performed 24 h 6 30 min after the time ofinitial immersion of the sample roll.10.5.1 Maintain specimens for the 24 h diametral compres-sion test at 75 6 5F (23.9 6 2.8C) and 50 6 10 % relativehumidity for the 24 h
43、 curing period.11. Report11.1 Report the following information:11.1.1 Product IdentityManufacturer, product description,product size (width and length) and manufacturing lot code;11.1.2 Initiation DataTotal immersion time and numberof squeezes used for initiation of polymerization;11.1.3 Set TimeAve
44、rage of the three measurements (inseconds);11.1.4 Constant Tension MethodManual or automated;11.1.5 Mandrel TypeType I or Type II;11.1.6 Testing SpeedReport crosshead or (actuator) dis-placement rate as inch/min (mm/min);11.1.7 Diametral Compression StrengthsAverage of thethree (3) calculated values
45、 for each roll tested at each timeinterval. Report the load type (peak failure or maximumdeflection); and11.1.8 MoldingDegree and duration of molding used on asecondary set of samples.12. Precision and Bias12.1 Precision and bias of this test method will be deter-mined after interlaboratory tests ar
46、e carried out and the resultstabulated. The interlaboratory tests will be carried out follow-ing Practices E691.13. Keywords13.1 orthopaedic casting tapediametral compressionstrength; orthopaedic casting tapemechanical testing; ortho-paedic casting tapesetting time; polyurethanebiomedicalapplication
47、s; polyurethane/fiberglass orthopaedic casting tapeAPPENDIX(Nonmandatory Information)X1. RATIONALEX1.1 The primary purpose of this test method is to providea standard method for determining the strength and setting timeof synthetic water-activated polyurethane fiberglass orthopae-dic casting tape. T
48、his includes sample preparation, testingprocedure, and data reporting.X1.2 Specimen preparation in this test method is not in-tended to duplicate all actual casting tape use. It is intended toproduce uniform samples upon which mechanical testing maybe performed with minimal variability.X1.3 Wrapping
49、 by hand may produce samples in whichthere are variations in adhesion between layers, or along thesample width because of variations in wrapping tension.Sample-to-sample variation may also be increased when usingmanual methods. Therefore, samples should be prepared usinga method that employs constant tension during wrapping of theplies (see Fig. 1 and Fig. 2).X1.4 Manual molding of the casting tape, while an integralpart of the normal cast application process, is extremelysubjective, making standardization of this process
