Plastics Technology

JUL 2017

Plastics Technology - Dedicated to improving Plastics Processing.

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INJECTION MOLDING Easy-to-Use Process Monitor Designed for Shop-Floor Technicians A coating applied via chemical vapor deposition (CVD) has been shown to extend tool life by up to three times. U.K.-based Hardide Coatings Ltd. (a plant opened in Martinsville, Va., last year) reports that the coating—a metallic tungsten matrix with dispersed nano particles of tungsten carbide—has been used so far only in extrusion. "Pelletizing dies have been tested extensively, and the coating increased their life significantly," a Hardide source said. "The coating is also expected to deliver benefits to injection mold tooling." Hardide notes that traditional coatings are line-of-sight techniques, best suited for coating external surfaces, and not able to coat the inside of an extrusion die. In the CVD process, materials are crystallized from the gas phase to produce a conformal coating, typically 50 microns (0.002 in.) thick. Since the CVD coating is applied in a vacuum chamber, the size of parts is limited—typically around "shoebox" size. Hardide says the pore-free CVD coatings are highly resistant to acids, helping to protect steel from acids emitted in processing PVC or some flame-retardant additives. The company also sees potential in coatings for tools running filled materials. The coatings are said to combine hardness with toughness, providing impact and crack resistance. 713-677-3504 • hardide.com Nordson Corp., New Castle, Pa., has developed a new screw-and-barrel package optimized specifically for processing polylactic acid (PLA) biopolymer. Compared with standard designs, the new package is said to offer higher throughputs and improved quality while resisting the corrosive and abrasive effects of PLA compounds. Developed in collaboration with PLA suppliers, Nordson's new Xaloy PLA screw/barrel package incorporates three key elements: 1) screw geom- etries designed specifically for PLA that increase throughput while minimizing shear and controlling melt temperature; 2) mixing segments that deliver a homog- enized melt; and 3) screw and barrel materials that resist the mildly corrosive effects of PLA and the abrasion caused by compound ingredients. Screws consist of 17-4 ph stainless steel with Xaloy X-183 hardfacing. For extrusion (photo, top), the Xaloy Effi- cient barrier screw features a patented Xaloy Stratablend II mixer that provides homogenized melt temperatures for enhanced quality and productivity. For injection molding, the Xaloy EasyMelt screw (photo, bottom) can be tailored to a specific PLA grade to provide optimum temperature control and rapid recovery. When mixing is required, the Xaloy Z-Mixer can be added, which is particularly valuable for applica- tions requiring high clarity. Barrels in the new package are lined with Xaloy X-800 inlay, a nickel-based alloy with tungsten carbide that provides enhanced abrasion and corrosion resistance. 800-897-2830 • nordson.com This month sees the commercial release of new injection molding process-monitoring software from RJG Inc., Traverse City Mich., that was previewed at the K 2016 show in Dusseldorf (see Jan. '17 Keeping Up). RJG's CoPilot is designed to be so simple and easy to use that it can help technicians of all experience levels keep a process on target. Unlike RJG's eDART system, which monitors both machine and mold variables and is aimed at engineers, the CoPilot focuses on the machine param- eters of interest to shop-floor technicians and does not require advanced training. CoPilot takes data directly from the sensors on the machine—such as linear position transducers, hydraulic-pressure transducers, and load cells. The CoPilot monitors variables (sensed directly or calculated) such as backpressure, fill time and pressure, shot size, cushion, transfer position, pack/hold times and pressures, cycle time, cooling time, part- removal time, and material viscosity. The system compares actual process parameters to setpoints and issues real- time notifications if the process is out of limits. In such a case, any non-conforming parts are automatically contained, elimi- nating the need for sorting. CoPilot also offers step-by-step instructions on how to bring a process back to set parameters by prioritizing the most important out-of- spec variables. The system records who fixed the issue and when. For medical and automotive molders that must adhere to a validated process, CoPilot performs automatic process audits, in place of periodic manual process checks to confirm that setpoints on the press match what is on the setup sheet. Instead, the CoPilot does this 24/7 and in real time. CoPilot records change log data, showing what parame- ters were changed, when, and by whom. 231-947-3111 • rjginc.com CVD Carbide Coating Puts Wear Resistance In Hard-to-Reach Places Screw & Barrel Package For Extruding, Molding PLA SCREWS/BARRELS TOOLING 52 JULY 2017 Plastics Technology PTonline.com With Technology Keeping Up

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