Smart Molding International 1-2021

42 smart_molding international 1/2021 sensors S ince 1971, Polyfab Corp. has been a custom thermoplastic injection molder. The American company supports the plastics molding industry needs of four major markets: medical, packaging, industrial, and commercial. In order to remain competitive in the ever-changing plastic molding indus - try, they must continuously adapt their monitoring processes with the ultimate goal of producing zero-defect quality assured parts. Brian Burhop is a Project Engineer with over 16 years of experience at Polyfab Corp. located in Sheboygan, Wisconsin. He takes the quality of their molded parts seriously. Monitoring the molding process for suspect parts prior to packaging or assembly easily with guaranteed results is key. For ten years now, cavity pressure technology with sensors and systems of Kistler have provided a highly effective, reliable basis for automated inspection. Integrated quality assurance increases customer satisfaction Burhop says, “Our partnership with Kistler came about because Polyfab Corp. is very much a molder based on scientific principles which we employ to establish and monitor our molding processes. Process monitoring and con - tainment is very important for our high- volume jobs. Our decision was based on very important factors, such as how user-friendly themonitoring equipment is, howeasy it is to acquire and interpret the data, how easily configurable it is with our machinery, and how easy it is to incorporate Kistler's sensors into the mold itself. Kistler's products were re - ally hands down the best choice for us in all those categories. Approximately 66% of Polyfab Corp. machinery is now equipped with Kistler monitoring and sensor technology.” The first challenge Burhop and his team faced was to greatly improve the accuracy of short-shot monitoring for a dispenser lid with a living hinge. To reduce non-fills during the injection molding process, the pressure at end of fill was monitoredwith a flushmounted sensor directly in the cavity. This allows formore accurate setting of the required minimum pressure which is affected by process variables including injection speed, and melt temperature. Burhop states, “Polyfab's customer return score prior to implementing Kistler in 2009 was above 10,000 PPM (parts per million). In 2017, we molded approximately 200million parts and our rate for customer returns was 98 PPM, which is `world class' performance. Our 2018 year-to-date PPMcustomer return rate is now `1 PPM'. This represents a drastic improvement after implement - ing Kistler's process monitoring systems (ComoNeo/ CoMo Injection), as well as Kistler's direct and indirect cavity pres - sure sensors into our machinery.” Automated assembly thanks to cavity pressure sensors Polyfab Corp. has also integrated Kistler's sensors into their automated assembly process, producing very posi - tive results. Burhop explains, “For auto - mated assembly in terms of parts which have a lot of value added as they step through the assembly process, Kistler's sensors ensure that we are not assem - Polyfab uses process monitoring systems from Kistler based on cavity pressure measurement to sustainably optimize the high-volume production of plastic parts for various industries. Thanks to them, it was possible to reduce the number of faulty parts in injection molding to a record-breaking 1 PPM (parts per million). How Polyfab trims its injection molding production to the highest quality