A basic study is reported of extrusion and injection molding for melts of polyethylene and polystyrene filled with glass fibers. It is shown that glass fibers cause large increases in end pressure losses and decreases in extrudate swell. Flow visualization of injection molding studies indicates that polymer melts containing high loadings of glass fibers exhibit jetting in end gated molds. This is attributed to the reduction in extrudate swell. To avoid jetting, special care is required in design of gating.
Gas mixtures comprising H2:Ar:CH4 at various flow ratios were fed to a microwave plasma system during the preparation of Ti implants to form anticoagulation and antibacterial films composed of carbon-based nanowires (NWs). When the H2-flow ratio was increased, a phase transition (amorphization (α) → (α + quasi-α) → (α + quasi-α + NWs) → (α + quasi-α + NWs + multilayer-like NWs (MLNWs)) → (NWs/MLNWs with nanograins)) was observed within the films formed on Ti during the microwave plasma discharge. In addition to producing a nanostructural film made of NWs, plasma carbonization caused the formation of an NW/nanograin phase that can enhance the hydrophobic and anticoagulation properties. Moreover, antibacterial tests also demonstrated the crucial role played by the hydrophobic films made of NWs in improving the antibacterial performance of the implants. The enhanced anticoagulation and antibacterial properties render the nanostructural films made of NWs as one of the promising materials that can be used in the heart valves, coronary artery stents, and dental implant surgical kits.
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