Plastics Engineering - May 2014 - (Page 56)

Industry PAtEnts By roger Corneliussen Melt Mixing U.s. Patent 8,647,550 (February 11, 2014), "Process for introducing an additive into a Polymer Melt," Kevin Philip nelson and Dan g. siegel (curwood, inc., Oshkosh, Wisconsin, Usa). Melt blending polymers and additives are common and necessary steps in forming most plastics. Proper additive dispersion is critically important and often not achieved. nelson and siegel developed a process resulting in uniform and complete distribution by adding a water dispersion to a melt in a twin-screw extruder. the water vapor is vented during extrusion, resulting in a uniform distribution of very small additive particles. the additive may be a colorant, opacifier, flavorant, perfume, anti-microbial, fungicide, antioxidant, protein, enzyme, antiblocking agent, antistatic agent, antifog agent, slip agent, light stabilizer, light absorber, process aid, release agent, a reactive indicator compound, or taggant. drug delivery U.s. Patent 8,637,466 (January 28, 2014), "Multi-arm Polymeric alkanoate conjugates," antoni Kozlowski, samuel P. McManus, Jennifer riggs-sauthier, Xiaoming shen, and Wen Zhang (nektar therapeutics, san Francisco, california, Usa). although many approaches have been devised for improving medical drug delivery, they all have drawbacks. For example, certain drugs, such as the alkaloids, are notoriously difficult to 56 solubilize. there is a need for improved methods for delivering drugs with adequate bioavailability, bioactivity, and ease of use, with reduced side-effects. Kozlowski et al. developed multiarmed star polymer complexes for administrating drugs with high doses. the carrier consists of a core with watersoluble polyethylene glycol-like branches. attached to the branches are spacers and active agents such as anticancer agents. the star copolymers enable increased drug loading while avoiding impurities. the multi-arm polymer complexes are effective as anti-cancer and anti-tumor agents. nanofiber spinning U.s. Patent 8,647,540 (February 11, 2014), "apparatuses Having Outlet Elements and Methods for the Production of Microfibers and nanofibers," Ed Peno, roger lipton, and stephen Kay (Fiberio technology corp., Mcallen, texas, Usa). Fibers having small (e.g., micrometer to nanometer) diameters are useful in different fields, from clothing to military. Electrospinning is a major production method to make small fibers, but it is difficult to upgrade to large-scale commercial production. Peno, lipton, and Kay produced microfibers and nanofibers using centrifugal spinning. Here, a polymer melt or solution is continuously fed into a rotating (1000 to 25,000 rpm) container with exit nozzles. the rotation forces the melt or solution through the nozzles. During rotation, the exiting streams are fed into a collector and conditioned. temperatures range from 4 to 440°c. candidate materials for spinning include polyolefins, polyacetals, polyamides, polyesters, cellulose ether and esters, polyalkylene sulfides, polyarylene oxides, and polysulfones. toughened Fiber-reinforced Plastics U.s. Patent 8,637,598 (January 28, 2014), "long-Fibre-reinforced, thermoplastic Moulding compound, Method for Production thereof and Use thereof," Heinz Bernd, Bruno Wagner, thomas Borgner, and Olaf Herd (ticona gmbH, suizbach (taunus), germany). Plastics, especially polyolefins, are inexpensive, combining low intrinsic weight, good processability on an industrial scale, and excellent resistance to chemical effects or moisture. their applications are greatly extended by fillers and fibers. there is, however, much room for improvement. Bernd et al. developed long fiberreinforced thermoplastic molding materials with outstanding impact strength. their materials typically consist of 30 to 90 wt% thermoplastic polyolefin, 9 to 69 wt% glass-like reinforcing fiber, and 1 to 30 wt% 0.1 to 0.2-micron mineral particles. the molding material is first produced by pultrusion, and then pelletized for molding. applications include appliances, electrical devices, and automobiles. stiffened Melts U.s. Patent 8,647,551 (February 11, 2014), "Process for Producing Moldings with an increase in the Melt stiffness," andreas Dowe, rainer goering, Martin | Plastics EnginEEring | MaY 2014 | www.4spe.org | www.plasticsengineering.org http://www.4spe.org http://www.plasticsengineering.org

Plastics Engineering - May 2014

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