1、Designation: F648 13Standard Specification forUltra-High-Molecular-Weight Polyethylene Powder andFabricated Form for Surgical Implants1This standard is issued under the fixed designation F648; the number immediately following the designation indicates the year of originaladoption or, in the case of
2、revision, the year of last revision.Anumber in parentheses indicates the year of last reapproval.Asuperscriptepsilon () indicates an editorial change since the last revision or reapproval.1. Scope1.1 This specification covers ultra-high molecular weightpolyethylene powder (UHMWPE) and fabricated for
3、ms 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 is subsequently produced (Section 5).This specification address
4、es material characteristics and doesnot apply to the packaged and sterilized finished implant.1.3 The requirements of this specification do not apply toUHMWPE virgin powder or fabricated forms intentionallycrosslinked or blended with other additives, for example,antioxidants.1.4 The biological respo
5、nse 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 values stated in SI units are to be regarded asstandard.1.6 The following precautionary caveat pertains only to thetest method portion, Section 7,
6、of this specification: 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
7、.2. Referenced Documents2.1 ASTM Standards:3D256 Test Methods for Determining the Izod PendulumImpact Resistance of PlasticsD638 Test Method for Tensile Properties of PlasticsD648 Test Method for Deflection Temperature of PlasticsUnder Flexural Load in the Edgewise PositionD790 Test Methods for Flex
8、ural Properties of Unreinforcedand Reinforced Plastics and Electrical Insulating Materi-alsD792 Test Methods for Density and Specific Gravity (Rela-tive Density) of Plastics by DisplacementD1505 Test Method for Density of Plastics by the Density-Gradient TechniqueD1898 Practice for Sampling of Plast
9、ics (Withdrawn 1998)4D4020 Specification for Ultra-High-Molecular-Weight Poly-ethylene Molding and Extrusion MaterialsF619 Practice for Extraction of Medical PlasticsF748 Practice for Selecting Generic Biological Test Methodsfor Materials and DevicesF749 Practice for Evaluating Material Extracts by
10、Intracuta-neous Injection in the RabbitF756 Practice for Assessment of Hemolytic Properties ofMaterialsF763 Practice for Short-Term Screening of Implant Materi-alsF813 Practice for Direct Contact Cell Culture Evaluation ofMaterials for Medical DevicesF895 Test Method forAgar Diffusion Cell Culture S
11、creeningfor CytotoxicityF981 Practice for Assessment of Compatibility of Biomate-rials for Surgical Implants with Respect to Effect ofMaterials on Muscle and Bone2.2 ISO Standards:5ISO 3451-1 PlasticsDetermination ofAsh, Part 1: GeneralMethodsISO 11542/2 PlasticsUltra-High Molecular Weight Poly-ethy
12、lene (UHMWPE) Moulding and ExtrusionMaterialsPart 2: Preparation of Test Specimens andDetermination1This specification is under the jurisdiction of ASTM Committee F04 onMedical and Surgical Materials and Devices and is the direct responsibility ofSubcommittee F04.11 on Polymeric Materials.Current ed
13、ition approved July 1, 2013. Published August 2013. Originallyapproved in 1980. Last previous edition approved in 2010 as F648 10a. DOI:10.1520/F0648-13.2The boldface numbers in parentheses refer to the list of references at the end ofthis specification.3For referenced ASTM standards, visit the ASTM
14、 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.4The last approved version of this historical standard is referenced onwww.astm.org.5Available from Interna
15、tional Organization for Standardization (ISO), 1, ch. dela Voie-Creuse, CP 56, CH-1211 Geneva 20, Switzerland, http:/www.iso.org.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States1ISO 9001 Quality Management Systems - RequirementsISO 134
16、85 Medical Devices Quality Management Systems Requirements for Regulatory Purposes3. Terminology3.1 Definitions of Terms Specific to This Standard:3.1.1 fabricated form, nany bulk shape of UHMWPE,fabricated from the virgin polymer powder and used during theprocess of fabricating surgical implants pr
17、ior 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-cable requirements of this specification. In present practice,this includes ram-extruded
18、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 and structure of thevirgin polymer.3.1.3 morphology index (MI), nratio of the total number
19、of 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 conditionsdescribed in A2.5.1 that has an essentially complete circum-ferential black boundary and a wh
20、ite 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 appears to trace out 50 % to 99 % of a flakesperimeter.3.1.6 virgin polymer powder, nform of UH
21、MWPE 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 accordance with Specification D4020.4.1.2 The resin type and solution viscosity number req
22、uire-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 Table 1.4.2.2 To promote uniformity between different lots of poly-mer powder, concentratio
23、n 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 1.4.3 Quality System Requirements:4.3.1 The UHMWPE powder as described in the scope ofthis spe
24、cification shall be produced in accordance with an ISO9001 or ISO 13485 certified Quality Management System.5. UHMWPE Fabricated Form Requirements5.1 Compositional Requirements:5.1.1 No stabilizers, antioxidants, or processing aids are tobe added to the virgin polymer powder during manufacture ofa f
25、abricated form.5.1.2 No stabilizers, antioxidants, or processing aids are tobe added to the fabricated form during manufacture of the finalimplant.5.2 Physical Requirements:5.2.1 Foreign Matter Requirements:5.2.1.1 When 5000 cm2is evaluated according to 7.2.2,there shall be no more than ten particle
26、s of extraneous mattervisible on the surface when visually inspected by a person withnormal or fully corrected 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 area examinedshall be reported.5.3 Mechanical Requi
27、rements:5.3.1 UHMWPE in fabricated form from which implantswill 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 temperature; Test Method D648 (1.8MPa), and Flexural modul
28、us; Test Methods D790 (secant, 2 %offset).5.4 Quality System Requirements:5.4.1 The UHMWPE fabricated forms as described in thescope of this specification shall be produced in accordance withan ISO 9001 or ISO 13485 certified Quality ManagementSystem.6. Sampling6.1 Where applicable, the requirements
29、 of this specificationshall be determined for each lot of powder and fabricated formby sampling sizes and procedures according to Practice D1898,or as agreed 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 m
30、ethod given in Specification D4020 at aconcentration of 0.02 %.TABLE 1 Requirements for UHMWPE PowdersProperty Test Method RequirementResin Type Type 1 Type 2 Type 3Viscosity Number, mL/g, ASTM D4020 (0.02 %) 2000-3200 3200 3200Elongation Stress, (Mini-mum)ASTM D4020 0.20 0.42 0.42Ash, mg/kg, (Maxim
31、um) ISO 3451-1 125 125 300Extraneous Matter, No.Particles, (Maximum)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.F648 1327.1.2 Determine the am
32、ount of extraneous matter by thefollowing procedure as agreed upon by 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 num
33、ber of particles ofextraneous matter in the four flasks.7.1.2.2 Visually examine (with 20/20 corrected vision ifnecessary) the four flasks and count the total number ofparticles of extraneous matter.7.1.3 Determine the following trace element concentrationsby the following methods, or by methods agr
34、eed upon by thepurchaser and seller.7.1.3.1 The elements Ti, Al, and Ca 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 determi
35、nedpotentiometrically, titrametrically, by neutron activationanalysis, by inductively coupled plasma mass spectroscopy(ICP/MS), or by the oxygen bomb combustion/UV-Vis spec-troscopy method.7.2 UHMWPE Fabricated Form:7.2.1 The requirement that there will be no addition of anystabilizer, antioxidant,
36、or processing aid during fabrication ofthe fabricated form shall be met by certification of thefabricator.7.2.2 Determine the amount of extraneous matter by thefollowing 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
37、Visually examine (with 20/20 corrected vision ifnecessary) a total area of 5000 cm2taken from locations withinthe fabricated form agreed upon by the purchaser and seller.7.2.3 Determine the density in accordance with Test Meth-ods D792 or D1505.7.2.4 Determine specific mechanical properties in accor
38、-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 otherwise specified, the testing described inTable 2 (except for ash) shall be conducted under standardconditions of 23 6 2C after sto
39、rage 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 long termclinical use in laboratory animals. The results of these studiesand the clinical history indicate an acceptable level of bi
40、ologi-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 of the materials are beingcontemplated, the recommendations of Practice F748 shouldbe considered and testing as described in Practi
41、ces F619, F749,F756, F763, F813, and F981 as well as Test Method F895.9. Keywords9.1 fabricated forms; powdered form; ultra-high molecularweight polyethyleneTABLE 2 Requirements for UHMWPE Fabricated FormsProperty Test Method RequirementResin Type Type 1 Type 2 Type 3Density, kg/m3ASTM D792 or D1505
42、 927-944 927-944 927-944Ash, mg/kg, (Maximum) ISO 3451-1 125 125 300Tensile Strength, 23C, MPa, (Mini-mum)ASTM D638, Type IV, 1.5 mm 0.5 mm,5.08 cm/minUltimate 40 40 27Yield 21 19 19Elongation, %, (Minimum) ASTM D638, Type IV, 5.08 cm/min 380 340 250Izod Impact Strength, kJ/m2, (Mini-mum)Annex A1 12
43、6 73 25F648 133ANNEXES(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 D256, Method
44、 A, UHMWPEgenerally 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 D256but introduces a much higher degree of stress concentrationinto the specimen by double notching with a razor b
45、lade. It isadvised that the user be familiar with Test Method D256 beforeattempting to use this test method.A1.2. ApparatusA1.2.1 The Izod type impact machine which conforms tothe requirements of Test Method D256, including the calibra-tion and checking methods, shall be used.A1.3. Test SpecimenA1.3
46、.1 The geometry and dimensions of the specimen aregiven in Fig. A1.1.A1.3.2 The specimens shall 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 No
47、tching of SpecimensA1.4.1 In the case of compression molding, the two notches(or width of two notches) shall be perpendicular to thedirection of application of molding pressure; if applicable. Theimpact resistance of a plastic material may be different if thenotch is perpendicular to, rather than pa
48、rallel to, the directionFIG. A1.1 Dimensions of Double Notched Izod Test SpecimenF648 134of molding. The same is true for specimens cut with or acrossthe grain of an anisotropic sheet or plate.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
49、 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. (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,perpendicularity, and offset of the two notches. One of thepossible measurement methods is given in A1.8.A1.5. ConditioningA1.5.1 ConditioningCondition the notched specimens at23 6 2C (73 6 4F) for not less than 16 h prior to testing.A1.5.2 Tes
