In this paper, high strain rate compression properties of aramid and ultrahigh molecular weight polyethylene composites in the out-of-plane direction are tested at room temperature on a Split Hopkinson Pressure Bar apparatus. Tests were conducted on composites reinforced with woven or Uni-Directional (UD) fabrics made from aramid or ultrahigh molecular weight polyethylene as well as on composites reinforced with hybrid reinforcement. The strain rate is varied in the tests by changing the projectile shooting pressure. Four different pressures 2, 4, 6 and 8 bar were selected to change the strain rate. Stress-strain and energy absorption behaviour of eight type of samples were noted. Hybrid samples showed better performance in the energy absorption compared with other samples. © SAGE Publications ...
The Ultra High Molecular Weight Polyethylene Fiber(UHMWPE Industry 2017 Market Research Report is a professional and in-depth study on the current state of the Ultra High Molecular Weight Polyethylene Fiber(UHMWPE industry.Firstly, the report provides a basic overview of the industry including definitions, classifications, applications and industry chain structure. The Ultra High Molecular Weight Polyethylene Fiber(UHMWPE market analysis is provided for the international market...
The Medical Grade Ultra-High Molecular Weight Polyethylene (UHMWPE) Market Research report is a professional and in-depth study on the current state of the.... ...
United States Ultra-high Molecular Weight Polyethylene (UHMWPE) Industry 2016 Market Research Report is a market research report available at US $3800 for a Single User PDF License from RnR Market Research Reports Library.
Global Medical Grade Ultra-High Molecular Weight Polyethylene (UHMWPE) Market Insights, Forecast to 2025 is a market research report available at US $3900 for a Single User PDF License from RnR Market Research Reports Library.
F2183-02(2008) Standard Test Method for Small Punch Testing of Ultra-High Molecular Weight Polyethylene Used in Surgical Implants (Withdrawn 2017)
Ultra-High Molecular Weight Polyethylene Market by Form (Sheets, Rods & Tubes), End-Use Industry (Aerospace, Defense, & Shipping, Healthcare & Medical, Mechanical Equipment), Region - Global - Market research report and industry analysis - 10828599
Global Ultra-High Molecular Weight Polyethylene Market Professional Survey Report 2019 Size and Share Published in 2019-09-02 Available for US$ 3500 at Researchmoz.us
[101 Pages Report] Check for Discount on Global and China Ultra High Molecular Weight Polyethylene (UHMWPE) Industry Report, 2017-2021 report by Research In China. Ultra High Molecular Weight Polyethylene (UHMWPE), a kind of linear...
... Ultra High Molecular Weight Polyethylene Market: global Industry - Market research report and industry analysis - 11295458
Uniaxial tension-unloading recovery, creep-recovery, and stress-controlled cyclic tests are first performed to investigate the recoverable viscoelasticity and irrecoverable viscoplasticity (including the uniaxial ratchetting) of ultrahigh molecular weight polyethylene (UHMWPE) polymer at room temperature. The results show that obvious time-dependent ratchetting occurs in the asymmetrical stress-controlled cyclic tension-compression and tension-tension tests of the UHMWPE, and total ratchetting strain consists of both recoverable viscoelastic and irrecoverable viscoplastic parts. Based on the experimental observation, a new viscoelastic-viscoplastic constitutive model is proposed to describe the time-dependent ratchetting of the UHMWPE. In the proposed model, the viscoplastic strain is set to be contributed simultaneously by the unified viscoplastic and creep ones. Meanwhile, a memory surface is introduced into the viscoelastic model to improve the description to the shapes of stress-strain ...
Ultra High Molecular Weight Polyethylene trade offers directory and Ultra High Molecular Weight Polyethylene business offers list. Trade leads from Ultra High Molecular Weight Polyethylene Suppliers and Ultra High Molecular Weight Polyethylene buyers provided by weiku.com.
Radiation cross-linked ultra high molecular weight polyethylenes (UHMWPEs) have been successfully used as wear resistant bearing surfaces in total joint arthroplasty. A recent development in this field is the incorporation of the antioxidant vitamin E into radiation cross-linked UHMWPE. This study investigates the effects of radiation cross-linking and vitamin E incorporation on the dielectric behavior of UHMWPE. The dielectric relaxations of virgin and 0.1 wt % vitamin E-blended UHMWPE and their irradiated counterparts (up to 300 kGy dose) were investigated. To determine the effect of vitamin E content alone, vitamin E-loaded UHMWPEs were used. The results showed that radiation cross-linking and vitamin E content both increased dielectric polarization in UHMWPE and under some conditions induced electrical conductivity. This result is significant because it shows that the conductive response of UHMWPE-bearing surfaces may depend on manufacturing processes and ...
Inquire for Ultra High Molecular Weight Polyethylene Fiber(UHMWPE) Market 2018 Competitive Analysis, Trends and Forecast till 2025, free sample copy report
Vanga-Bouanga, C. et Savoie, S. et Fréchette, M. F. et David, E.. 2015. « Synthesis and characterization of Ultra High Molecular Weight Polyethylene filled with boron nitride micro and nano-particles ». In 2015 Electrical Insulation Conference (EIC) (Seattle, WA, USA, June 7-10, 2015), p. 234-237. Piscataway, NJ, USA : IEEE ...
Research Report on Global Medical Ultra High Molecular Weight Polyethylene Sales Market Report 2017. The Report includes market price, demand, trends, size, Share, Growth, Forecast, Analysis & Overview.
This paper investigates the mechanism of wear-particle generation when a single asperity is passed over the surface of UHMWPE. A single asperity is modelled using a conical diamond-tip indenter attached to a nano-scratch tester. Scratches are produced by passing the indenter over the surface of the polymer in a single pass and multiple passes on a single track or on orthogonally intersecting tracks. The debris-generation process, as observed in the nano-scratch test, is complex and depends upon the direction of scratches. It is found that the rate of wear-debris generation is much higher when two consecutive scratches orthogonally intersect each other compared to when the scratches are made on the same track. Wall formation was observed between orthogonally intersecting scratches, and it is believed that this is central to the low-cycle wear mechanism in these systems. © 2004 Springer Science+Business Media, Inc ...
Copyright in the material you requested is held by the American Society of Mechanical Engineers (unless otherwise noted). This email ability is provided as a courtesy, and by using it you agree that you are requesting the material solely for personal, non-commercial use, and that it is subject to the American Society of Mechanical Engineers Terms of Use. The information provided in order to email this topic will not be used to send unsolicited email, nor will it be furnished to third parties. Please refer to the American Society of Mechanical Engineers Privacy Policy for further information ...
Most wear testing of orthopedic implant materials is undertaken with dilute bovine serum used as the lubricant. However, dilute bovine serum is different to the synovial fluid in which natural and artificial joints must operate. As part of a search for a lubricant which more closely resembles synovial fluid, a lubricant based on a mixture of sodium alginate and gellan gum, and which aimed to match the rheology of synovial fluid, was produced. It was employed in a wear test of ultra high molecular weight polyethylene pins rubbing against a metallic counterface. The test rig applied multidirectional motion to the test pins and had previously been shown to reproduce clinically relevant wear factors for ultra high molecular weight polyethylene. After 2.4 million cycles (125 km) of sliding in the presence of the new lubricant, a mean wear factor of 0.099 × 10−6 mm3/Nm was measured for the ultra high molecular weight polyethylene pins. This was over an order of magnitude less than when bovine serum was
Delrin acetal resins are thermoplastic polymers manufactured by the polymerization of formaldehyde. The use of Delrin in total hip prostheses was first suggested in the mid-1960s. The attraction of Delrin is that the creep resistance is ten times that of ultrahigh molecular weight polyethylene, the most usually used plastic material. In addition, Delrin is about five times harder than ultrahigh molecular weight polyethylene and thus will resist the abrasive action of bone chips and acrylic cement particles.. Since 1970, Delrin acetal polymer has been used in the Christiansen total hip prosthesis and in the Christiansen endoprosthesis. Up to the end of 1977, approximately 7000 surgical procedures had been carried out with the prosthesis. The results have been very good. Prostheses removed for cases of infection or loosening have not shown wear on the articulating Delrin components. Furthermore, histological studies of the surrounding tissue show a benign tissue response similar to that seen ...
0077]Preferably, the UHMWPE made from this embodiment has a polymeric structure with less than about 50% crystallinity, less than about 290 Å lamellar thickness and less than about 940 MPa tensile elastic modulus. Conventional UHMWPE, e.g., a bar stock, a shaped bar stock, a coating, or a fabricated article is provided. By conventional UHMWPE is meant commercially available high density (linear) polyethylene of molecular weights greater than about 500,000. Preferably, the UHMWPE starting material has an average molecular weight of greater than about 2 million. By initial average molecular weight is meant the average molecular weight of the UHMWPE starting material, prior to any irradiation. It is preferred that this UHMWPE is surrounded with an inert material that is substantially free of oxygen, e.g., nitrogen, argon or helium. In certain embodiments, a non-inert environment can be used. The UHMWPE is heated above its melting temperature for a time sufficient to allow all the crystals to ...
The Effect of Pressure-Induced Flow (PIF) Processing on the Thermal Stability and Mechanical Properties of Ultra-High Molecular Weight Polyethylene (UHMWPE) Gel
TY - JOUR. T1 - Electrostatic field may regulate proliferation and immune responses of macrophages induced by polyethylene wear particles. AU - Fang, Hsu Wei. AU - Sung, Ya Ting. AU - Su, Chen Ying. AU - Chen, Chia Chun. PY - 2017/8/1. Y1 - 2017/8/1. N2 - Effects of electrostatic field on the macrophage responses induced by ultra-high molecular weight polyethylene (UHMWPE) wear particles have been investigated in this study. An inverted cell culture system was applied to study the interactions between UHMWPE wear particles and macrophage cells. The electrostatic field induced device (EFID) was installed on the cell culture system. The high voltage and low current stimulations generated from EFID were first applied to the UHMWPE particles/macrophage co-culture system. The proliferation and tumor necrosis factor-alpha, interleukin (IL)-6, and IL-1β cytokine expressions of J774A.1 macrophage cells were analyzed. The EFID applied voltage of 0.5 kV, 1.0 kV, 1.3 kV, and 1.6 kV were investigated. Our ...
The extraction of the polyethylene material in this study shows that there is a molecular weight difference between the unaged and aged material, with the aged material showing broadening in the molecular weight distribution. This change can be explained by oxidative degradation, which is supported by the oxidation index. The test methodology shows that a larger ratio of solvent to sample is required to ensure extraction without gelation of the extracted material, and that 4 hours is sufficient to extract the larger molecular weight species. The impact of the molecular weight change on in vivo performance, however, cannot be discerned from this test ...
At present time the number of implantations of joint replacements as well as their revisions increases. Higher demands are required on the quality and longevity of implants. The aim of this work was to determine the degree of oxidative degradation and the amount of free/residual radicals in selected ultra-high molecular weight polyethylene (UHMWPE) components of the joint replacements and demonstrate that the measured values are closely connected with quality and lifetime of the polymer components. We tested both new (4 samples) and explanted (4 samples) UHMWPE polymers for total joint replacements. The samples were characterized by infrared spectroscopy (IR), electron spin resonance (ESR) and microhardness (MH) test. The IR measurements yielded the values of oxidation index and trans-vinylene index. The ESR measurements gave the free radicals concentration. In the group of new polyethylene components, we found oxidation index values ranging from 0.00-0.03 to 0.24. The trans-vinylene index values ranged
The cellular reaction to wear debris may result in the failure of an artificial joints fixation to the skeleton. The influence of debris opsinization on cell activity has received little attention. This study seeks to establish whether different proteinaceous culture environments may invoke variant cellular responses to debris challenge. Consideration of the zeta potential of a low density polyethylene particle group and an ex vitro ultrahigh molecular weight polyethylene particle group revealed that the nature of the protein adsorbants is related to the concentration of the proteins in solution. Furthermore, the composition of the adsorbed layer was shown to vary with the spectra of proteins in solution. In standard cell culture conditions zeta potential approached zero, indicating the high probability of particle agglomeration. Cell challenge studies with U937 macrophages showed that BSA and FCS protein adsorption mediated increased cell adhesion, while bovine IgG showed little change over ...
Introduction. The radiation crosslinking of ultra-high molecular weight polyethylene (UHMWPE) to enhance the properties of implants made from this polymer was reported as early as 1974 by Dumbleton.1 These studies were carried out at very high irradiation doses in air or nitrogen and resulted in excessive surface oxidation of the polymer and poor wear characteristics. The general radiation crosslinking of UHMWPE in the presence of gaseous mediating agents to enhance the mechanical properties of the polymer was reported as early as 1972 by Mitsui2 and in 1973 by Hagiwara.3. In order to reduce the required irradiation dose, authors 1 and 2 (Du Plessis and Grobbelaar) initiated a research and development programme in 1974 to investigate the potential of the radiation crosslinking of UHMWPE for application in orthopaedic prostheses by using a mediating gas or mixtures of mediating gases to enhance the degree of crosslinking of the UHMWPE and lower the required radiation dose. Almost 25 years later ...
Post-irradiation melting of ultra-high molecular weight polyethylene (UHMWPE) reduced the oxidation potential of UHMWPE in vivo. After mid-term (5- 10 yrs) use in vivo, there is detectable oxidation in irradiated and melted joint implant retrievals. The absorption of the synovial fluid lipid squalene was identified as a possible factor initiating oxidation. We investigated the role of lipids in UHMWPE oxidation by asking: (1) Do other synovial fluid lipids initiate oxidation in irradiated and melted UHMWPE?; (2) What is the effect of the absorption of multiple lipids on UHMWPE oxidation?; (3) How does lipid-initiated oxidation in vitro compare to what is observed in long-term retrievals? We diffused emulsified single and mixed lipids into irradiated and melted UHMWPE and accelerated aged them ...
... Looking for Ultra High Molecular Weight & Bb Uhmwpe Rbrb in UAE ? Get Suppliers / Manufacturers / Retailers of Ultra High Molecular Weight & Bb Uhmwpe Rbrb in UAE
TY - JOUR. T1 - Demonstration of a new technique using radioisotope tracers to measure the backside wear rate on tibial inserts. AU - Warner, Jacob. AU - Gladkis, Laura. AU - Smith, Paul. AU - Scarvell, Jennie. AU - Timmers, Heiko. PY - 2012. Y1 - 2012. N2 - Local backside wear measurements on ultrahigh molecular weight polyethylene (UHMWPE) tibial inserts in LCS mobile bearing knee prostheses have been performed using a new radioisotope tracing technique. The radioisotope tracers 97Ru and 101mRh were synthesized via a fusion evaporation reaction and recoilimplanted into cylindrical plugs of UHMWPE. The labelled plugs were carefully fitted into tibial inserts at two relevant locations. With bovine serum acting as a lubricant, the tibial inserts were then worn in vitro for 500,000 and 780,000 cycles, respectively, in a pneumatic knee motion simulator. Results reflect the non-linear change of wear during the wear-in phase and its evolution to a long-term steady-state rate. This new technique shows ...
Integra made sure to raise its voice among extremities players in fiscal year 2016 (ended Dec. 31) by releasing the Cadence Total Ankle System. Cadence added to the Integras growing mix of ankle replacement products. The company made its foray into ankle replacement in 2015 by acquiring the Salto Talaris and Salto Talaris XT prostheses from Tornier, and Cadence complements this product line with several features to accommodate many patient anatomies. Cadences side-specific, anatomical tibial and talar components avoid fibular impingement and minimize resected talar bone to preserve the ankles vascularity. Further, Cadences bearing inserts are made from a highly crosslinked ultra-high molecular weight polyethylene (UHMWPE) to improve wear characteristics. Cadences first clinical use in the United States was achieved in April 2016, and in Europe in September ...
I stopped by Colorado Plastic Products in Boulder today. They sell scraps of all sorts of materials, including high density polyethylene (HDPE), polytetrafluoroethylene (PTFE/Teflon), and ultra-high molecular weight polyethylene (UHMWPE), all of which are attractive for making ice carving tools.. I needed a low friction surface for a new hot wire ice cutter Im working on, so I picked out a nice sheet of UHMWPE. It has terrific properties for the application, including a low coefficient of friction, low water absorption, and a wide operating temperature range. Lars had suggested the stuff because it is used for ski bases and dog sled runners, so it should work very well.. ...
1. A process of producing a high strength polyethylene multi-filament yarn comprising the steps of:a) forming a slurry of an ultrahigh molecular weight polyethylene (UHMWPE) having an initial intrinsic viscosity (IV0) at least about 10 dl/g and an antioxidant in a solvent for said UHMWPE having an atmospheric pressure boiling point at least about 180.degree. C. at a temperature that is below the temperature at which the UHMWPE will dissolve in said solvent, the weight ratio of said UHMWPE to said solvent being from about 5:95 to about 95:5 and the weight ratio of said antioxidant to said solvent being from about 10 parts per million to about 1000 parts per million;b) feeding said slurry to an intermeshing co-rotating twin screw extruder wherein the screws in said twin screw extruder are comprised of multiple segments having a root diameter of Dr millimeters, an outside diameter of Do millimeters, the ratio Dr/Do is R, the rotational speed of the screws is ω revolutions per minute and following ...
The PRODISC®-L Total Disc Replacement is an artificial intervertebral disc made from metal and plastic that is used to treat pain associated with degenerative disc disease (DDD). DDD is defined as discogenic back pain (pain resulting from a degenerated intervertebral disc) with degeneration of the disc confirmed by patient history and radiographic studies. The PRODISC®-L Total Disc Replacement is implanted to replace a diseased or damaged intervertebral disc during a surgical procedure called spinal arthroplasty.. The PRODISC®-L Total Disc Replacement consists of three parts:. Two metal (cobalt-chrome alloy) endplates that are anchored to the top and bottom surfaces of the spinal bones (vertebrae) and a plastic (ultra-high molecular weight polyethylene, or UHMWPE) inlay that fits between the two endplates.. The plastic inlay and endplates help restore the natural distance between the two vertebrae (disc height). The top (superior) endplate can slide over the domed part of the inlay, which can ...
The Mobi-C® Cervical Disc Prosthesis (Mobi-C®) is a single use device for cervical intervertebral disc replacement at one level or two contiguous levels from C3 to C7 designed to maintain/restore segmental motion and disc height. The components of the Mobi-C® include a cobalt, chromium, molybdenum (CoCrMo per ISO 5832-12) alloy superior spinal plate, an inferior CoCrMo spinal plate, and an ultra-high molecular weight polyethylene (UHMWPE per ISO 5834-2) mobile insert. The inner contact surfaces of the superior and inferior spinal plates are spherical and flat, respectively. This allows for fully congruent contact surfaces between the spinal plates and mobile insert. The two lateral stops of the inferior plate are designed to control and limit the mobility of the mobile insert. The spinal plates, both superior and inferior, feature two rows of teeth which are designed to aid in initial and long term fixation and stability. The teeth are designed to sink into the bone to facilitate endplate ...
When Olympic hopefuls are sliding down icy tracks at speeds of 93 mph, those watching at the event or on television arent usually thinking about how the track was constructed, or what will happen to it when the Games are over.. But from a financial, environmental and engineering perspective, those questions are important-perhaps even more important than who wins the gold medal.. Thats why Purdue University professor Jan-Anders Mansson has been working for three years to engineer the ice out of Olympic sports like bobsled, luge and skeleton. Instead of the traditional ice, Mansson has proposed using an ultra-high molecular weight polyethylene to construct the surface of the 1.2-mile tracks.. Utilizing the same type of metal used to construct traditional ice tracks, the chosen polyethylene, a rotary device and a thermal camera, Mansson was able to accurately test the real-world sport at a representative laboratory scale.. In each experiment, the polyethylene-the winner out of 8 materials Mansson ...
BioPointe filtered tips are manufactured in USA and are certified by an independent laboratory to be free of RNase, DNase, DNA and Pyrogens. Sterilization is done through an Electronic Beam Process that does not alter the color or make the plastic brittle. Manufactured only using the highest-grade of virgin polypropylene and implementing a unique thin-wall design Super Seal provides a soft, flexible material to effortlessly achieve optimal fit and seals on a variety of pipettors Molded with ultra-high molecular weight polyethylene, the filters are completely inert and consistent in porosity. This insures that the BioPointe filters will not impede airflow and will protect samples and pipettor from harmful contamination. Because BioPointe manufactures its filters in a clean-room facility, every component is free of detrimental nucleic acid and enzymes. BioPointe Scientific uses the highest quality plastics and best manufacturing practices to consistently produce a superior product. With its thin-wall
The implant stability and biomechanical response of periprosthetic bone in acetabulum around total hip joint replacement (THR) devices depend on a host of parameters, including design of articulating materials, gait cycle and subject parameters. In this study, the impact of shell design (conventional, finned, spiked, and combined design) and liner material on the biomechanical response of periprosthetic bone has been analyzed using finite element (FE) method. Two different liner materials: high density polyethylene-20% hydroxyapatite-20% alumina (HDPE-20%HA-20%Al2O3) and highly cross-linked ultrahigh molecular weight polyethylene (HC-UHMWPE) were used. The subject parameters included bone condition and bodyweight. Physiologically relevant load cases of a gait cycle were considered. The deviation of mechanical condition of the periprosthetic bone due to implantation was least for the finned shell design. No significant deviation was observed at the bone region adjacent to the spikes and the fins. ...
[137 Pages Report] Check for Discount on Global High-density Polyethylene Market 2018-2022 report by Technavio. About High-density Polyethylene HDPE is a type of polyethylene...
TY - JOUR. T1 - Gene Expression Profile of Macrophage-Like U937 Cells in Response to Polyethylene Particles. A Novel Cell-Particle Culture System. AU - Matsusaki, Takashi. AU - Kawanabe, Keiichi. AU - Ise, Kentaro. AU - Nakayama, Tomitaka. AU - Toguchida, Junya. AU - Nakamura, Takashi. PY - 2007/10. Y1 - 2007/10. N2 - We investigated the gene expression profiles of U937 cells after contact with polyethylene particles. U937 cells were differentiated with phorbol 12-myristate 13-acetate, and cocultured with either retrieved polyethylene particles or commercially produced polyethylene particles (Ceridust 3615, Clariant Japan, Tokyo, Japan). To achieve consistent contact with the polyethylene particles, we used a rotating device. Phagocytosis of the polyethylene particles or retrieved polyethylene particles by differentiated U937 cells stimulated the release of cytokines including interleukin 1β, interleukin 6, interleukin 8, and vascular endothelial growth factor. Microarray analysis revealed that ...
2008. Journal Articles. Varadarajan R., Dapp, E.K., and Rimnac, C.M. (2008) Static Fracture Resistance of Ultra High Molecular Weight Polyethylene using the Single Specimen Normalization Method. Polymer Testing, 27:260-268. (PMC3563271).. Varadarajan, R., Rimnac, C.M. (2008) Evaluation of J-initiation Fracture Toughness of Ultra-high-molecular-weight Polyethylene used in Total Joint Replacements. Polymer Testing, 27:616-620. (PMC2911369) (PMID:20671815).. Rimnac, C., Pruitt, L. Implant Wear Symposium 2007 Engineering Work Group. How do material properties influence wear and fracture mechanisms? J. Am. Acad. Orthop. Surg. 2008;16 Suppl 1:s94-100. (PMID:18612023).. Sobieraj, M.C., Kurtz, S.M., Wang, A., Manley, M., Rimnac, C.M. (2008) Notched Stress-strain Behavior of a Conventional and a Sequentially Annealed Highly Crosslinked UHMWPE. Biomaterials, 29:4575-83. (PMC3573887) (PMID:18801567).. Medel, F., Kurtz, S.M., Klein, G., Levine, H., Sharkey, P., Austin, M., Kraay, M., Rimnac, C.M. (2008) ...
For high-demanding applications we also offer semiproducts from E_CTFE, PFA, FEP etc which resist against aggresive chemicals and extreme low and high temperatures. If you are interested in these materials, we would be pleased to discuss specefics with you.. ...
The present invention is directed to a polymeric prosthesis precoated with a bone cement compatible polymer. The bone cement compatible polymer coating, is provided by an activated powder mixture of polymethyl methacrylate and ultra high molecular weight polyethylene which is bonded to the outer surface of the prosthesis by sintering. Once bonded to a polymeric prosthesis in accordance with the present invention, the precoat strengthens the interface between a bone cement and a prosthesis when the prosthesis is later implanted. The inner layer of the prosthesis may be provided of cross-linked UHMWPE powder sintered with virgin UHMWPE powder or fibers to provide a intermediate layer(s) of the coating present on the prosthesis. The precoat also decreases the likelihood that the prosthesis will loosen and break away from the cement over time. The polymeric implant product of the present invention is particularly well suited for use as an acetabular cup or a tibia plateau in replacing hip joints and knee
Background: The objective of this 13-year prospective evaluation of highly cross-linked ultra high molecular weight polyethylene (HXLPE) was to (1) assess the long-term wear of HXLPE articulating with 2 femoral head sizes using radiostereometric analysis (RSA) and to (2) determine if osteolysis is a concern with this material through the use of plain radiographs and computerized tomography (CT). Methods: All patients received a Longevity HXLPE liner with tantalum beads and either a 28-mm or 36-mm femoral head. Twelve patients (6 in each head size group) agreed to return for 13-year RSA, plain radiograph, and CT follow-up. The 1-year and 13-year plain radiographs as well as the CT scans were analyzed for the presence of osteolysis. Results: The 13-year mean +/- standard error steady-state wear was 0.05 +/- 0.02 mm with no significant increase over time or between the 2 head size groups. Two patients CT scans showed radiolucent regions in the acetabulum of 4.51 cm(3) and 11.25 cm(3), ...
Quadrant Engineering Plastic Products (QEPP) is the worlds leading manufacturer of semi-finished products made from general engineering and high-performance plastics. Quadrant also designs, develops and produces finished parts and solutions for a broad variety of applications in many different industries globally. Its product range extends from polyamide (PA), polyacetal (POM) and ultra high molecular weight polyethylene (UHMW-PE) to high-performance materials such as fluoroplastics and polybenzimidazole (PBI), which features temperature resistance to over 425C (800F) while maintaining total dimensional stability. The semi-finished products are machined or thermoformed and used in a variety of industries ranging from electronics through packaging machinery to chemical processing for applications where properties such as non-stick characteristics, abrasion resistance, dimensional stability, chemical and acid resistance or purity are extremely important.. Quadrants global teams of product ...
Microporous film of ultra high molecular weight polyethylene with a high degree of moisture vapor transmission rate and a permeability to air that lies within a narrow range and a process for the production of a film with a high degree of moisture vapor transmission rate and a permeability to air that lies within a narrow range from a polyolefin by extruding a solution of the polyolefine in a first solvent, followed by cooling, the removal of the solvent and stretching of the film, in which the surface of one and only one side of the film is brought into close contact with a second solvent for the polyolefin before the film is contacted with the cooling agent.
The ceramic heads are made of either zirconia or alumina and are highly polished to reduce wear on the hip socket, which is made from Ultra High Molecular Weight Polyethylene (UHMPE). The head is fitted to a Morse-type taper titanium shaft that is then cemented into the femur. The heads are produced in a range of sizes with bore sizes and taper angles adjusted according to customer requirements. LUSAS is being used to investigate load-to-failure, fatigue and impact for these various configurations.. ...
A stent-graft fabricated from a thin-walled, high strength material provides for a more durable and lower profile endoprosthesis. The stent-graft comprises one or more stent segments covered with a fabric formed by the weaving, knitting or braiding of a biocompatible, high tensile strength, abrasion resistant, highly durable yarn such as ultra high molecular weight polyethylene. The one or more stent segments may be balloon expandable or self-expanding. The fabric may be attached to the stent segments utilizing any number of known materials and techniques. The fabric may be attached to the stent segments utilizing an attachment device that secures the fabric to a strut of the stent segment by sandwiching the fabric between itself and the stent strut.
Sisal fibers and finely powdered high-density polyethylene were surface functionalized using dichlorosilane (DS) under R-F plasma conditions to improve interfacial adhesion between the two dissimilar substrates. The functionalized polyethylene (70%) and sisal (30%) were compounded on four different ways using thermokinetic mixer and injected molded into composites specimens for test. Some improvements in mechanical properties of the composites due to the plasma treatments were achieved. Scanning Electronic Microscopy (SEM) data indicated that some compatibilization of the two plasma modified phases had taken place as compared to non-plasma treated composite. ...
Crystallization of polycarbonate (PC) was attempted by a precipitated method in a ternary system of PC/solvent/nonsolvent. Chloroform was used as a solvent, and isopropanol was used as a nonsolvent. Crystallization of PC was clearly observed as a powdery state when chloroform/isopropanol mixtures were prepared by 68/32 and 61/39 vol%. Crystallinity of PC was evaluated by differential scanning calorimeter and X-ray diffractometer. As the difference of solubility parameters between PC and binary solvent/nonsolvent mixtures became smaller, the relative crystallinity of PC was increased. The highest degree of PC crystallization was obtained when chloroform/isopropanol was mixed by 61/39 vol%. Subsequently, crystallized PC was used as a filler to high-density polyethylene (HDPE) composite. HDPE composite incorporated by crystallized PC filler improved its mechanical and thermal properties. Flexural modulus was increased from 620 to 990 N/mm2, and flexural strength was increased from 720 to 1080 ...