Case Study: Software

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This is the simulated thermal output from an analysis Schnipke Engraving did on Sigma for a 50-cavity tool. The designer then morphed it onto the real mold in the machine.

Schnipke Engraving Co. (Ottoville, OH)—a leading manufacturer of plastic injection molded components and related services—boasts high-performance material experts specializing in precision micro-injection moldmaking, molding and over-molding operating in two world-class manufacturing facilities, equipped with automated assembly and packaging. A SIGMA customer since June 2010, Schnipke has completed many successful projects using SIGMASOFT® Thermoplastic Simulation Software from (Schaumburg, IL) SIGMA Plastic Services, Inc. in its design-to-part strategy.

The company, serving the medical, healthcare, industrial, defense, aerospace, automotive and consumer electronics markets, gets the CAD design solidified with NX from Siemens PLM Software (Plano, TX). “The iterations required in the simulation process are accomplished very timely due to the synchronous modeling that NX offers at Version 6,” notes Schnipke’s Mold Design Manager Greg Karns. “NX offers a tremendous amount of power without all the baggage that typical designs carry. The design environment has changed much over the last 30 years. Until a friend of mine sent me a video of the synchronous modeling, I had not seen anything in the past 10 years that impressed me enough to make a jump to another platform. In today’s world, it is critical to be compatible with many platforms and cultures.”

Enter SIGMASOFT for CAE. According to Shawn J. Schnee, Director of Process Engineering and Technology at Schnipke, in both the performance effectiveness and time savings provided by the stress analysis, part cooling, shear/fill runner balancing, pressure loss predictions and cycle time optimization inherent in this Sigma’s simulation software, Schnipke saw an immediate benefit from using SIGMASOFT. “This software is able to detect cavity filling behaviors of plastic materials, over-molding of inserts, curing behaviors of different thicknesses as well as design process validation,” he explains. “In addition, SIGMASOFT has the ability to consider other main stage variables such as water placement, various tool steel (conductivity), heating elements and hot runner systems. Moreover, SIGMASOFT® considers other types of molding processes such as LSR injection, insert molding and multi-component while simulating pressure loss accuracy within 1 to 7 percent—when all of the main factors are considered appropriately.”

Schnee notes Sigma is not an autonomous program—it requires an experienced user that must have a working knowledge of tool design, molding and materials (plastic and steel) engineering. “There can be a significant learning curve not only in the software but understanding and correlating the results of the analysis,” he comments. “Invest in a good training regiment as well as experienced staff. Once you start seeing the benefits of the software, you may begin to trust the models that are coming out of engineering to be gospel instead of just good guesses.” Schnee adds that it is difficult to determine how long training will take, as it depends on how familiar the designer is with the other disciplines involved in mold manufacture like metallurgy, processing and mechanical aspects.

Schnipke recently had success with a complex project. “We had to build four 50-cavity micro-molds with part weight of .0044 grams per cavity. There were a lot of challenges inherent in this application, including part weight, amount of cavities, tolerance banding as well as utilizing Ultem (PEI) as the material for the part,” Schnee elaborates. “And, the parts themselves had to be symmetrical to a mating component, which made runner balancing 10 times more complex. We had nearly 30 iterations of runner design through SIGMASOFT and after we built and ran the tool, we had zero modifications to the runner/gate designs since they were all built to our 3-D model. The balanced filling of each cavity is evident in our mold balance studies; part weights are within .0003 grams.

Moreover, Schnipke Engraving has found SIGMASOFT provides a comprehensive approach to determine the effect of polymer morphology based on their mold steel selections, delivery systems and water flow strategies. With this type of information, Schnipke is able to minimize the many inherent variables in the molding process that typically lead to costly iterative steps during design and process development. “I can’t disclose the financial advantages of utilizing SIGMASOFT, but I can say we have reduced our iterative design changes by 90 percent, compared to the way we previously did business,” he states.

Summing up the benefits of SIGMASOFT, Schnipke believes that SIGMASOFT goes above and beyond other simulation software. “Through our company’s lean initiatives, we’ve identified that our iterative designs were eating up our build timelines and ultimately disappointing our customers,” he says. “We have identified the main disconnect was in our predictive analysis tools. Our prior CAE estimates were very ambiguous and easily misinterpreted. We have seen immediate benefits of a far more accurate forecast we receive from SIGMASOFT, with less ‘tweaking’ time.”

For more information:
Schnipke Engraving Co. / (419) 453-3376
sschnee@schnipkeengraving.com / schnipkeengraving.com

Siemens PLM Software / (262) 207-3110
info.plm@siemens.com / plm.automation.siemens.com

SIGMA Plastic Services, Inc. / (847) 558-5600
contact@3dsigma.com / 3dsigma.com