NPE2018 Show Daily - Wednesday

NPE is truly ‘Breaking the Mold’ as a multifaceted experience, with activities, discoveries and opportunities to satisfy the needs of anyone who works in the plastics industry or has a need to know about plastics

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WEDNESDAY NPE 2018 : THE PLASTICS SHOW SHOW DAILY EXTRUSION | PRINTING | CONVERTING Booth W6663 WINDMOELLER & HOELSCHER P A S S I O N   F O R   I N N O V A T I O N If you extrude, print on or convert film, we manufacture the machinery you need. Technology you can count on. Come see what's new: TURBOCLEAN automated resin purging for fast job changes Film Performance Monitor (FPM) for FILMEX II cast film lines More Automaঞon = More Capable Robots By Mahew H. Naitove Plascs Technology Cartesian robots with the addiঞon of a servo wrist are an alternaঞve to six-axis arঞculated robots in some tasks. (Photo: Yushin) Walking around the injecঞon molding exhibits at NPE2018, you have no doubt noঞced that a machine standing on its own molding parts has become less common than elaborate automated cell demonstraঞons involving mulঞple upstream and downstream operaঞons. This reflects a gradual transiঞon occurring in molding plants. "We're seeing more beside-the- press automaঞon," says Chris Parrillo, naঞonal sales manager of Yushin America. "More inspecঞon, packaging, assembly, and product serializaঞon using hot stamping, laser engraving, barcode labeling, and RFID chips." "We're seeing more and more being done with takeout robots," adds Dino Caparco, Yushin's engineering operaঞons manager. "That means higher speeds and more complex end- of-arm tooling for jobs like insert molding or in-mold labeling combined with part removal." One consequence is growing interest in use of machine vision to assist robots. Robot vendors aribute this to mold- ers' increased emphasis on quality and to the declining cost and increasing miniaturizaঞon of vision components. It thus becomes ever more cost-effecঞve to mount cameras on the mold, machine frame, or the robot in order to check for short shots, color, proper degaঞng, proper insert loading, and com- plete ejecঞon from all caviঞes. There is also a growing trend to use vision for 100% inspecঞon of parts for dimensional measurement, label orientaঞon, and surface flaws. As many as 16-18 parameters can be checked at once on every part. Aendees at the last NPE in 2015 will have noted the ability of vision-guided robots to play basketball or miniature golf. In the real world, this translates into ability to locate parts on a conveyor and orient them for stacking and packing. Jim Healy, vice president of sales and markeঞng for Sepro America, notes that vision applicaঞons today typically sঞll rely on custom soluঞons; the future will almost certainly bring more plug-and-play simplicity. In Healy's view, the trend toward cell automaঞon explains the prevalence of six-axis, arঞculated robots at this year's NPE. Notwithstanding the extreme versaঞlity of such robots, most suppliers agree that jointed-arm ro- bots are beer applied to downstream funcঞons than to pull- ing parts out of a mold. As compared with linear robots, they are less aracঞve in speed, reach, payload capacity, and size of the work envelope that needs guarding—not to menঞon cost and addiঞonal programming effort. On the other hand, they may be advantageous in low-headroom circumstances. For the most part, however, sources at vendors like Sepro, Yushin, and Wimann Baenfeld agree that a linear robot with a servo wrist that adds five to seven degrees of freedom can compete favorably with jointed-arm types. At NPE, you can see linear robots operaঞng alone, or in pairs—handing off from one to another—or teaming up with jointed-arm robots for downstream operaঞons. Downstream cell operaঞons are ferঞle ground for other kinds of robots that may be less familiar to NPE aendees. One is SCARA robots, a type of very fast, extremely compact device typically used in assembly operaঞons to pick and place small, lightweight parts. They typically have three or four axes of freedom and speeds of up to 200 picks/min. They can access extremely confined spaces. A second type of high-speed, light-duty robot is the "spider," delta, or parallel robot. It has three arms connected to universal joints at the base. It can have three to six degrees of freedom and is capa- ble of up to 300 picks/min. Almost faster than the eye can follow, these robots can reposiঞon mulঞcavity parts for downstream operaঞons a[er they have been demolded by a linear robot, all within the press cycle, so no buffer area is required. A newer type of robot that has been gaining aenঞon late- ly is so-called "collaboraঞve" robots (or "cobots"), which are typically disঞnguished by modest cost, easy lead-through- teach programmability, and—most important—ability to oper- ate safely around humans without hard guarding in some ap- plicaঞons. Typically based on six- or seven-axis, jointed-arm designs, these robots use onboard vision and torque sensors to sense unintended contact with a foreign object and react very quickly to halt further movement. They are generally considered suitable for pick-and-place operaঞons down- stream of a molding machine, not for machine tending. As you can see here at the show, a growing number of vendors are coming out with such robots, and mainstream Cartesian robot suppliers are finding cobots to be a valuable addiঞon to their line. It is becoming ever more cost-effec- ve to mount cameras on the mold, machine frame, or the robot in order to check for short shots, color, proper degang, proper insert loading, and complete ejecon from all cavies. 22

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