with their suppliers. Using such simulation soſtware, suppliers and designers can work together from the beginning of the development of a new part to design parts that are optimized for performance, castability and costs. Process simulation thereby becomes an invaluable com-
munication tool between designers and production engineers in an environment of ever shorter product development processes. Indeed, many OEMs now require their casting suppliers to use MagmaSoſt and oſten refuse to procure parts from foundries not utilizing this technology. While simulation has been established as a product design
tool in the plastics industry serving the medical device seg- ment, process simulation tools have not been adopted by manufacturing overall. Te main reason is that the simula- tion tools that were originally intended to be used only in the design process lacked the ability to consider the complex- ity of the entire injection-molding process. SigmaSoſt was introduced by Sigma, a fully owned subsidiary of Magma, to provide process simulation soſtware for polymer injection processes. It even simulates the elastomer injection process, i.e. for LSRs (liquid silicone rubbers), a material category not covered by traditional design simulation tools. Tis process-chain integrated simulation makes simulation
accessible to everyone, not only “simulation and meshing spe- cialists.” SigmaSoſt has been lauded as “the next generation of polymer simulation” because of its combination of ease-of-use and its capability to consider all details of the entire mold- making and molding process. Tis opens the utilization of this technology to designers with product responsibilities and production engineers, as no finite element meshing experience is required to use it. Based on the success and vast experience of its parent company Magma, Sigma is determined to provide comprehensive, accurate, yet easy-to-use soſtware to product producers and buyers of plastic and rubber parts.
Implementation at Tessy Plastics Tessy Plastics (Elbridge, NY), a global contract manu-
facturer serving the medical device industry, decided to implement this new approach and has been using SigmaSoſt for a year and the benefits are clear: the predicted cost and time-savings estimates have been met or exceeded. “First shot success” is becoming a regular occurrence at Tessy and doesn’t happen by accident. Te optimization of current production processes is accomplished daily. Process simula- tion soſtware must be comprehensive to meet the challenge of easily combining so many material, process and design variables. As with any advanced technology, training is required to facilitate successful implementation quickly. Te processor has fully trained five engineers in its use. Hav- ing a group of people trained, working as a team, eases the implementation of such new technology. It is very important to be able to share information and bounce ideas between
the team to speed up that learning process. Besides teaching the functionality of the soſtware, the provider (Sigma) also offered on-site implementation assistance within the existing engineering team. Te following is one example of the many successes that
the company realized in its medical business since the addi- tion of SigmaSoſt one year ago. Tessy was challenged by its customer to reduce the cycle
time of a product. One of the options discussed was to consider adding conformal cooling. A common method for implement- ing conformal cooling is to build the cavities using DMLS (Di- rect Metal Laser Sintering). Tis process is costly in comparison to more conventional tooling practices, so, before proceeding, the company ran a thermal analysis to both optimize the cool- ing design and to evaluate the conformal cooling against the original conventional cooling. Tis would help Tessy determine if the added cost in tooling would result in enough savings in cycle time to pay for the production changes. A multicycle thermal analysis was run on the original
tooling design with conventional cooling to determine the number of cycles required to stabilize the mold tempera- ture. Te simulated process was based on the actual current production process. An analysis was run on both the original and the conformal designs to determine the difference in solidification time. Te simulation of the initial design for the conformal cooling revealed that the original water layout did not control the temperature in the location that had the greatest impact on cycle time and, therefore, the design could be improved with conformal cooling. Without using process simulation and its multicycle capability, this would have been a very costly and time-consuming exercise for Tessy. Using process simulation, however, the company was able to quickly determine the root cause of the problem and engineer an optimum design. Te utilization of comprehensive process simulation like
MagmaSoſt and SigmaSoſt has an impact on almost every department of a metalcasting or molding operation. At Tessy, SigmaSoſt is located in the process engineering department and essentially allows the engineers to visualize every detail of the mold or part at any point in the overall process. Within the engineering department, it drives the user to be very specific about the process inputs which, in turn, improves the overall understanding and knowledge of the outcome. Its position within the company also allows for the simultaneous development of process and tooling as well as the documenta- tion of those developments. Tis is one aspect of how process simulation not only improves the communication within the process engineering department, but also improves the communication to the shop floor, explaining why the use of specific parameters to stay within a defined process window is necessary to assure the production of good parts, from the beginning to the end of the production run.