1、Designation: F 648 07e1Standard Specification forUltra-High-Molecular-Weight Polyethylene Powder andFabricated Form for Surgical Implants1This standard is issued under the fixed designation F 648; the number immediately following the designation indicates the year oforiginal adoption or, in the case
2、 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.e1NOTETable 1 was editorially corrected in June 2007.1. Scope1.1 This specification covers ultra-high m
3、olecular weightpolyethylene powder (UHMWPE) and fabricated forms in-tended for use in surgical implants.1.2 The requirements of this specification apply to UHM-WPE in two forms. One is virgin polymer powder (Section 4).The second is any form fabricated from this powder fromwhich a finished product i
4、s subsequently produced (Section 5).This specification addresses material characteristics and doesnot apply to the packaged and sterilized finished implant.1.3 The provisions of Specification D 4020 apply. Specialrequirements detailed in this specification are added to describematerial which will be
5、 used in surgical implants.1.4 The biological response to polyethylene in soft tissueand bone has been well characterized by a history of clinicaluse (1, 2, 3)2and by laboratory studies (4, 5, 6).1.5 The following precautionary caveat pertains only to thetest method portion, Section 7, of this speci
6、fication: Thisstandard does not purport to address all of the safety concerns,if any, associated with its use. It is the responsibility of the userof this standard to establish appropriate safety and healthpractices and determine the applicability of regulatory limita-tions prior to use.2. Reference
7、d Documents2.1 ASTM Standards:3D 256 Test Methods for Determining the Izod PendulumImpact Resistance of PlasticsD 638 Test Method for Tensile Properties of PlasticsD 648 Test Method for Deflection Temperature of PlasticsUnder Flexural Load in the Edgewise PositionD 790 Test Methods for Flexural Prop
8、erties of Unreinforcedand Reinforced Plastics and Electrical Insulating MaterialsD 792 Test Methods for Density and Specific Gravity (Rela-tive Density) of Plastics by DisplacementD 1505 Test Method for Density of Plastics by the Density-Gradient TechniqueD 1898 Practice for Sampling of Plastics4D 4
9、020 Specification for Ultra-High-Molecular-WeightPolyethylene Molding and Extrusion MaterialsF 619 Practice for Extraction of Medical PlasticsF 748 Practice for Selecting Generic Biological Test Meth-ods for Materials and DevicesF 749 Practice for Evaluating Material Extracts by Intracu-taneous Inje
10、ction in the RabbitF 756 Practice for Assessment of Hemolytic Properties ofMaterialsF 763 Practice for Short-Term Screening of Implant Mate-rialsF 813 Practice for Direct Contact Cell Culture Evaluation ofMaterials for Medical DevicesF 895 Test Method for Agar Diffusion Cell Culture Screen-ing for C
11、ytotoxicityF 981 Practice for Assessment of Compatibility of Bioma-terials for Surgical Implants with Respect to Effect ofMaterials on Muscle and Bone2.2 ISO StandardsISO 527 Plastics: Determination of Tensile Properties5ISO 3451-1 PlasticsDetermination of Ash, Part 1: Gen-eral Methods5ISO 11542/2,
12、PlasticsUltra-High Molecular Weight Poly-ethylene (UHMWPE) Moulding and ExtrusionMaterialsPart 2: Preparation of Test Specimens andDetermination53. Terminology3.1 Definitions of Terms Specific to This Standard:1This specification is under the jurisdiction of ASTM Committee F04 onMedical and Surgical
13、 Materials and Devices and is the direct responsibility ofSubcommittee F04.11 on Polymeric Materials.Current edition approved Feb. 1, 2007. Published February 2007. Originallyapproved in 1996. Last previous edition approved in 2004 as F 648 04.2The boldface numbers in parentheses refer to the list o
14、f references at the end ofthis specification.3For 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.4Withdrawn.5Avai
15、lable from American National Standards Institute (ANSI), 25 W. 43rd St.,4th Floor, New York, NY 10036, http:/www.ansi.org.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.3.1.1 fabricated form, nany bulk shape of UHMWPE,fabricated fro
16、m the virgin polymer powder and used during theprocess of fabricating surgical implants prior to packaging andsterilization.3.1.1.1 DiscussionThis form results from the applicationof heat and pressure to the virgin polymer powder, and thematerial characteristics of this form are subject to the appli
17、-cable requirements of this specification. In present practice,this includes ram-extruded bars or molded blocks from whichthe final product form is machined, or a molded shape which issubsequently trimmed.3.1.2 generic property, nthat property which is deter-mined solely by the chemical composition
18、and structure of thevirgin polymer.3.1.3 morphology index (MI), nratio of the total numberof Type A and Type B indications (see Annex A2) to the totalsurface area examined in cm2.3.1.4 Type A non-fused flake, na Type A non-fused flake(A2.4.1 and Fig.A2.1) is an indication visible under conditionsdes
19、cribed in A2.5.1 that has an essentially complete circum-ferential black boundary and a white center.3.1.5 Type B non-fused flake, na Type B non-fused flake(A2.4.2 and Fig.A2.2) is an indication visible under conditionsdescribed in A2.5.1 that has a partially circumferential blackboundary that appea
20、rs to trace out 50 % to 99 % of a flakesperimeter.3.1.6 virgin polymer powder, nform of UHMWPE asobtained from the powder manufacturer and prior to fabricationinto a bulk shape.4. Virgin UHMWPE Powder Requirements4.1 Generic Properties:4.1.1 The virgin polymer shall be a homopolymer of ethyl-ene in
21、accordance with Specification D 4020.4.1.2 The resin type and solution viscosity number require-ments are listed in Table 1.4.2 Nongeneric Properties:4.2.1 When a 300 g sample is prepared and viewed inaccordance with 7.1.2, there shall be no more particles ofextraneous matter than that specified in
22、Table 1.4.2.2 To promote uniformity between different lots of poly-mer powder, concentration limits for trace elements have beenestablished and are listed in Table 1.4.2.3 When determined as described in ISO 3451-1, themean ash of duplicate samples shall not exceed the limitsestablished in Table 1.5
23、. UHMWPE Fabricated Form Requirements5.1 Compositional Requirements:5.1.1 No stabilizers or processing aids are to be added to thevirgin polymer powder during manufacture of a fabricatedform.5.2 Physical Requirements:5.2.1 Foreign Matter Requirements:5.2.1.1 When 3200 cm2is evaluated according to 7.
24、2.2,there shall be no more than ten particles of extraneous mattervisible on the surface when visually inspected by a person withnormal (corrected, if necessary) vision.5.2.2 Morphology Requirements:5.2.2.1 When evaluated according to Annex A2 the calcu-lated morphology index (MI) and total surface
25、area examinedshall be reported.5.3 Mechanical Requirements:5.3.1 UHMWPE in fabricated form from which implantsshall be made shall meet the requirements listed in Table 2.5.3.2 The following mechanical tests may be conductedbased on agreement between the vendor and purchaser:5.3.2.1 Deflection temper
26、ature; Test Method D 648 (1.8MPa), and Flexural modulus; Test Methods D 790 (secant, 2 %offset).6. Sampling6.1 Where applicable, the requirements of this specificationshall be determined for each lot of powder and fabricated formby sampling sizes and procedures according to PracticeD 1898, or as agr
27、eed upon between the purchaser and seller.7. Test Methods7.1 UHMWPE Powder:7.1.1 Determine the solution viscosity number in accor-dance with the method given in Specification D 4020 at aconcentration of 0.02 %.7.1.2 Determine the amount of extraneous matter by thefollowing procedure as agreed upon b
28、y the purchaser andseller.7.1.2.1 A 300 g sample is divided into four 75 g samples.Place a 75 g sample in each of four 1000 mL Erlenmeyerflasks, add 400 mL isopropyl alcohol, shake 5 min, and letsettle for 5 min. Count the total number of particles ofextraneous matter in the four flasks.7.1.2.2 Visu
29、ally examine (20/20 corrected vision if neces-sary) the four flasks and count the total number of particles ofextraneous matter.7.1.3 Determine the following trace element concentrationsby the following methods, or by methods agreed upon by thepurchaser and seller.7.1.3.1 The elements Ti, Al, and Ca
30、 may be determined byatomic absorption (AA) or emission spectroscopy (ES); induc-tively coupled plasma mass spectroscopy (ICP/MS); or induc-tively coupled plasma spectroscopy (ICP).7.1.3.2 The element chlorine (Cl) may be determined po-tentiometrically, titrametrically, by neutron activation analysi
31、s,TABLE 1 Requirements for UHMWPE PowdersProperty Test Method RequirementResin Type Type 1 Type 2 Type 3Viscosity Number, mL/g, ASTM D 4020 (0.02 %) 2000-3200 3200 3200Elongation Stress,(Minimum)ASTM D 4020 0.20 0.42 0.42Ash, mg/kg, (Maximum) ISO 3451-1 125 125 300Extraneous Matter, No.Particles, (M
32、aximum)4.2.1 3325Titanium, mg/kg, (Maximum) 7.1.3.1 40 40 150Aluminum, mg/kg, (Maximum) 7.1.3.1 20 20 100Calcium, mg/kg, (Maximum) 7.1.3.1 5550Chlorine, mg/kg, (Maximum) 7.1.3.2 30 30 90 Editorially corrected.F64807e12by inductively coupled plasma mass spectroscopy (ICP/MS),or by the oxygen bomb com
33、bustion/UV-Vis spectroscopymethod.7.2 UHMWPE Fabricated Form:7.2.1 The requirement that there will be no addition of anystabilizer or processing aid during fabrication of the fabricatedform shall be met by certification of the fabricator.7.2.2 Determine the amount of extraneous matter by thefollowin
34、g procedure.7.2.2.1 Prepare a number of test specimens from the fabri-cated form as agreed upon by the purchaser and seller.7.2.2.2 Visually examine (20/20 corrected vision if neces-sary) a total area of 3200 cm2taken from locations within thefabricated form agreed upon by the purchaser and seller.7
35、.2.3 Determine the density in accordance with Test Meth-ods D 792 or D 1505.7.2.4 Determine specific mechanical properties in accor-dance with the methods listed in Table 2. Mechanical testspecimens shall be produced by methods that represent thoseused to produce the fabricated form.7.2.5 Unless oth
36、erwise specified, the testing described inTable 2 (except for ash) shall be conducted under standardconditions of 23 6 2C after storage of the test specimens forat least 16 h.8. Biocompatibility8.1 This material has been shown to produce a well char-acterized level of biological response following l
37、ong termclinical use in laboratory animals. The results of these studiesand the clinical history indicate an acceptable level of biologi-cal response in the applications in which the material has beenutilized. When new applications of the material, or modifica-tion to the material or physical forms
38、of the materials are beingcontemplated, the recommendations of Practice F 748 shouldbe considered and testing as described in Practices F 619,F 749, F 756, F 763, F 813, and F 981 as well as Test MethodF 895.9. Keywords9.1 fabricated forms; powdered form; ultra-high molecularweight polyethyleneANNEX
39、ES(Mandatory Information)A1. IMPACT STRENGTHA1.1 General DescriptionA1.1.1 This test method covers the determination of theimpact resistance of Ultra-High Molecular Weight Polyethyl-ene (UHMWPE) which is extremely impact resistant. Whentested according to Test Method D 256, Method A, UHMWPEgenerally
40、 gives a non-break type for failure, rendering the testresult invalid. This test method specifies the same type ofpendulum impact test machine as given in Test Method D 256but introduces a much higher degree of stress concentrationinto the specimen by double notching with a razor blade. It isadvised
41、 that the user be familiar with Test Method D 256before attempting to use this test method.TABLE 2 Requirements for UHMWPE Fabricated FormsProperty Test Method RequirementResin Type Type 1 Type 2 Type 3Density, kg/m3ASTM D 792 orD 1505927-944 927-944 927-944Ash, mg/kg, (Maximum) ISO 3451-1 150 150 3
42、00Tensile Strength, 23C, MPa,(Minimum)AASTM D 638, Type IV,5.08 cm/minUltimate 40 40 27Yield ISO 527, 100 mm/min. 21 19 19Elongation, %, (Minimum)AASTM D 638, Type IV,5.08 cm/min380 340 250ISO 527, 100 mm/min.Izod Impact Strength, kJ/m2,(Minimum)BAnnex A1 126 73 25Charpy Impact Strength, kJ/m2,(Mini
43、mum)BISO/CD 11542/2.3 180 90 30AEither Test Method D 638 or ISO 527 may be used to determine tensilestrength and elongation, however the ISO 527 method will be considered thereferee method.BEither Charpy or Izod impact strength may be determined, however, theCharpy test will be considered the refere
44、e method.F64807e13A1.2 ApparatusA1.2.1 The Izod type impact machine which conforms tothe requirements of Test Method D 256, including the calibra-tion and checking methods, shall be used.A1.3 Test SpecimenA1.3.1 The geometry and dimensions of the specimen aregiven in Fig. A1.1.A1.3.2 The specimens s
45、hall be made from the fabricatedform.A1.3.3 Each specimen shall be free of twist and shall bebounded by mutually perpendicular pairs of plane parallelsurfaces, free from scratches, pits, and sink marks.A1.4 Notching of SpecimensA1.4.1 Notching shall be done on the sides parallel to thedirection of a
46、pplication of molding pressure; if applicable.A1.4.2 A 4.57 6 0.076 mm (0.180 6 0.003 in.) deep notchshall be made with a suitable machine by pressing in a 0.25mm (0.010 in.) thick single edge razor blade with a 15included angle at the cutting edge. The notching speed shall beless than 508 mm/min. (
47、20 in./min.).Anew blade shall be usedafter notching 40 specimens.A1.4.3 The calibration of the notching machine shall bechecked by direct measurement of the notch depth, perpen-dicularity, and offset of the two notches. One of the possiblemeasurement methods is given in A1.8.A1.5 ConditioningA1.5.1
48、ConditioningCondition the notched specimens at23 6 2C (73 6 4F) for not less than 16 h prior to test.A1.5.2 Test ConditionsConduct the test in the standardlaboratory atmosphere of 23 6 2C (73 6 4F).A1.6 ProcedureA1.6.1 At least five and preferably ten individual determi-nations of impact value must
49、be made on each sample to betested under the conditions prescribed.A1.6.2 Measure the width of each specimen in the areabetween notches twice with a micrometer to the nearest 0.025mm (0.001 in.) and record its average width. Carefully measurethe distance between the notch roots on the two sides of thespecimen. Use of an optical microscope may improve theaccuracy of this measurement. Record the average value andmultiply this number by the width of the specimen to get theremaining unnotched cross section area, AR. Also record theidentifying markings of the speci
